Editions to the Widget Manual

Editions to the Widget Manual

[Mauro Aranda]

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Hi everyone,

Prompted by [1], I started to work (slowly!) on a revision to the Widget
Manual.

My goals were to make it descriptive, well-organized, comprehensive, and
up-to date.  I also tried to preserve as much text as I could, although
I have the feeling that from the diff it might not look like that.

I added descriptions for the widget creation mechanism and added
mentions to the inheritance mechanism and completion mechanism, for
example.  I couldn't find the words to describe the :inline widgets
(there's a FIXME there).

I felt like it wasn't well-organized, so I rearranged some chapters.
Previously, commands and user options were described in various places,
and I tried to put them under common chapters.  I moved the default
widget description to be the very first one documented, so all
properties and default behavior can be described up-front.

To be comprehensive, I tried to cover all the properties that I felt
made sense, and with those descriptions I feel like the programmer
reading the library can acquire a better sense of how to use the
library.  I would like to add examples for the creation of widgets, and
my plan is to do that eventually.

And well, to be up-to-date it doesn't need much description from me.  I
added a lot of widgets that were previously undocumented, although I
did left out some that didn't seem to me like important enough (like the
insert-button, delete-button).  I did add mentions to those widgets, so
I think the curious reader can go on and inspect those widgets with the
Widget Browser.

At this point, I feel comfortable to share what I've done so far, so
that I can get some feedback.  Please help me by fixing my English,
recommending some cross-references, and of course, reviewing in general.
I hope this version is good enough for a first draft, and I'll
appreciate any comments I receive.

TIA,
Mauro.

[1]: https://lists.gnu.org/archive/html/emacs-devel/2023-07/msg00306.html



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From 1969dcccb4c9b2882cd2fedff3312cab700e4d5b Mon Sep 17 00:00:00 2001
From: Mauro Aranda <maurooaranda@gmail.com>
Date: Wed, 16 Aug 2023 20:25:22 -0300
Subject: [PATCH] A revision to the Widget manual

* doc/misc/widget.texi (Widgets Basics, Working with Widgets)
(Widgets and the Buffer, Widget Gallery, Customization): New chapters.
(Basic Types, Sexp Types): Demote to subsections.
(Widget Browser): Rename to Inspecting Widgets.
(Widget Properties): Remove.

(Top): Adapt menu to changes.
(Introduction): Rearrange text.  Move warnings to a better place, and
user options to the Customization chapter.
(User Interface): Don't fully describe commands and customization
options here.
(Setting Up the Buffer): Expand on widget creation process and add
documentation for useful functions which deal with
creation/conversion.
(Defining New Widgets): Expand the documentation on define-widget.
All relevant properties moved to the description of the default
widget, in Widget Gallery.
(Utilities): Add some more useful functions not previously documented.
(Wishlist): Remove out-of-date items.
---
 doc/misc/widget.texi | 2730 +++++++++++++++++++++++++++++++-----------
 1 file changed, 2043 insertions(+), 687 deletions(-)

diff --git a/doc/misc/widget.texi b/doc/misc/widget.texi
index 13b37ab5b54..41881378ab0 100644
--- a/doc/misc/widget.texi
+++ b/doc/misc/widget.texi
@@ -49,14 +49,16 @@ Top
 * Introduction::
 * User Interface::
 * Programming Example::
+* Widgets Basics::
 * Setting Up the Buffer::
-* Basic Types::
-* Sexp Types::
-* Widget Properties::
+* Working with Widgets::
+* Widgets and the Buffer::
+* Widget Gallery::
 * Defining New Widgets::
-* Widget Browser::
+* Inspecting Widgets::
 * Widget Minor Mode::
 * Utilities::
+* Customization::
 * Widget Wishlist::
 * GNU Free Documentation License::
 * Index::
@@ -68,7 +70,7 @@ Introduction
 Most graphical user interface toolkits provide a number of standard
 user interface controls (sometimes known as ``widgets'' or ``gadgets'').
 Emacs doesn't really support anything like this, except for an
-incredibly powerful text ``widget.''  On the other hand, Emacs does
+incredibly powerful text ``widget''.  On the other hand, Emacs does
 provide the necessary primitives to implement many other widgets
 within a text buffer.  The @code{widget} package simplifies this task.
 
@@ -85,13 +87,13 @@ Introduction
 @item editable-field
 An editable text field.  It can be either variable or fixed length.
 @item menu-choice
-Allows the user to choose one of multiple options from a menu, each
-option is itself a widget.  Only the selected option will be visible in
-the buffer.
+Allows the user to choose one of multiple options from a menu, where
+each option is itself a widget.  Only the selected option is visible
+in the buffer.
 @item radio-button-choice
 Allows the user to choose one of multiple options by activating radio
-buttons.  The options are implemented as widgets.  All options will be
-visible in the buffer.
+buttons.  The options are implemented as widgets.  All options are
+visible in the buffer, with the selected one marked as chosen.
 @item item
 A simple constant widget intended to be used in the @code{menu-choice} and
 @code{radio-button-choice} widgets.
@@ -201,12 +203,6 @@ User Interface
 
 Editable text fields are created by the @code{editable-field} widget.
 
-@strong{Warning:} In an @code{editable-field} widget, the editable
-field must not be adjacent to another widget---that won't work.
-You must put some text in between.  Either make this text part of
-the @code{editable-field} widget itself, or insert it with
-@code{widget-insert}.
-
 The @code{:format} keyword is useful for generating the necessary
 text; for instance, if you give it a value of @code{"Name: %v "},
 the @samp{Name: } part will provide the necessary separating text
@@ -215,17 +211,9 @@ User Interface
 @code{:size} keyword, the field will extend to the end of the
 line, and the terminating newline will provide separation after.
 
-@strong{Warning:} In an @code{editable-field} widget, the @samp{%v} escape
-must be preceded by some other text in the @code{:format} string
-(if specified).
-
 The editing text fields are highlighted with the
 @code{widget-field-face} face, making them easy to find.
 
-@deffn Face widget-field-face
-Face used for other editing fields.
-@end deffn
-
 @section Buttons
 
 @cindex widget buttons
@@ -233,24 +221,9 @@ User Interface
 Some portions of the buffer have an associated @dfn{action}, which can
 be @dfn{invoked} by a standard key or mouse command.  These portions
 are called @dfn{buttons}.  The default commands for activating a button
-are:
-
-@table @kbd
-@item @key{RET}
-@deffn Command widget-button-press @var{pos} &optional @var{event}
-Invoke the button at @var{pos}, defaulting to point.
-If point is not located on a button, invoke the binding in
-@code{widget-global-map} (by default the global map).
-@end deffn
-
-@kindex mouse-2 @r{(on button widgets})
-@item mouse-2
-@deffn Command widget-button-click @var{event}
-Invoke the button at the location of the mouse pointer.  If the mouse
-pointer is located in an editable text field, invoke the binding in
-@code{widget-global-map} (by default the global map).
-@end deffn
-@end table
+are @code{widget-button-press} and @code{widget-button-click}.  The
+user typically interacts with the buttons with a key, like @key{RET},
+or with the mouse buttons.
 
 There are several different kind of buttons, all of which are present in
 the example:
@@ -286,33 +259,15 @@ User Interface
 displayed as GUI buttons when possible.
 @end table
 
-To make them easier to locate, buttons are emphasized in the buffer.
-
-@deffn Face widget-button-face
-Face used for buttons.
-@end deffn
-
-@defopt widget-mouse-face
-Face used for highlighting a button when the mouse pointer moves across
-it.
-@end defopt
+To make them easier to locate, buttons are emphasized in the buffer
+with a distinctive face, like @code{widget-button-face} or
+@code{widget-mouse-face}.
 
 @section Navigation
 
 You can use all the normal Emacs commands to move around in a form
-buffer, plus you will have these additional commands:
-
-@table @kbd
-@item @key{TAB}
-@deffn Command widget-forward &optional count
-Move point @var{count} buttons or editing fields forward.
-@end deffn
-@item @kbd{M-@key{TAB}}
-@itemx @kbd{S-@key{TAB}}
-@deffn Command widget-backward &optional count
-Move point @var{count} buttons or editing fields backward.
-@end deffn
-@end table
+buffer, plus you will have these additional commands to navigate from
+widget to widget: @code{widget-forward} and @code{widget-backward}.
 
 @node Programming Example
 @chapter Programming Example
@@ -414,267 +369,794 @@ Programming Example
   (widget-setup))
 @end lisp
 
+@node Widgets Basics
+@chapter Widgets Basics
+@cindex widget object
+The Widget Library deals with widgets objects.  A widget object has
+properties whose value may be anything, be it numbers, strings,
+symbols, functions, etc.  Those properties are referred to as keywords
+and are responsible for the way a widget is represented in a buffer,
+and control the way a user or a program can interact with it.
+
+@cindex widget inheritance
+The library defines several widget types, and gives you a way to
+define new types as well.  In addition, widgets can derive from other
+types, creating a sort of widget inheritance.  In fact, all widgets
+defined in the Widget Library share a common parent, the @dfn{default}
+widget.  In this manual, when we talk about a default behavior, we
+usually mean the behavior as defined by this @code{default} widget.
+@xref{Widget Gallery}, for a description of each defined widget.
+
+Defining a new type that derives from a previous one is not mandatory
+to create widgets that work very different from a specified type.
+When creating a widget, you can override any default property,
+including functions, that control the widget.  That is, you can
+specialize a widget on creation, without having to define it as a new
+type of widget.
+
+In addition to the function for defining a widget, this library
+provides functions to create widgets, query and change its properties,
+respond to user events and destroy them.  The following sections
+describe them.
+
+@cindex widget value
+One important property of a widget is its @dfn{value}.  All widgets
+may have a value,  which is stored in a so-called @dfn{internal format}.
+For the rest of Emacs, the widget presents its value in a so-called
+@dfn{external format}.  Both formats can be equal or different, and
+each widget is responsible for defining how the conversion between
+each format should happen.
+
+@c FIXME: Briefly describe inline widgets?
+@c The inline concept is described elsewhere, and it's difficult to
+@c describe.
+
+The value property is an important property for almost all widgets,
+and perhaps more important for @code{editable-field} widgets.  This
+type of widgets allow the user to edit them via the usual editing
+commands in Emacs.  They can also be edited programmatically.
+@strong{Important:} You @emph{must} call @code{widget-setup} after
+modifying the value of a widget before the user is allowed to edit the
+widget again.  It is enough to call @code{widget-setup} once if you
+modify multiple widgets.  This is currently only necessary if the widget
+contains an editing field, but may be necessary for other widgets in the
+future.
+
+@cindex widget properties
+If your application needs to associate some information with the widget
+objects, for example a reference to the item being edited, it can be
+done with the @code{widget-put} and @code{widget-get} functions.  The
+property names, as shown, are keywords, so they must begin with a
+@samp{:}.
+
 @node Setting Up the Buffer
 @chapter Setting Up the Buffer
+@cindex widget creation, widget conversion
+To show the widgets in a buffer, you have to create them.  Widget
+creation is actually a two-step process: conversion and creation per
+se.  With simple projects, usually the conversion step isn't really
+important, and you only care about widget creation, so feel free to
+skip the conversion description until you really need to know it.
+
+Widget conversion is the process that involves taking a widget
+specification and transforming it into a @dfn{widget} object, suitable
+to be created, queried and manipulated with other widget functions.
+Widget creation is the process that takes a widget object and actually
+inserts it in the buffer.
+
+The simplest function to create a widget is @code{widget-create}, which
+gets a widget specification and returns a widget object.
+
+@defun widget-create type [ keyword argument ]@dots{} args
+Create and return a widget of type @var{type}, converting it.
+
+@var{type} is a symbol that specifies a widget type.  @var{keyword}
+may be one of the properties supported by the widget type, and
+@var{argument} specify the value for that property.  These keyword
+arguments can be used to overwrite the keyword arguments that are part
+of @var{type} by default, as well as to provide other properties not
+present in @var{type} by default.  @var{args} holds additional
+information for the creation of @var{type} and each widget type is
+responsible for handling that information in a specific way.
+
+The syntax for the @var{type} argument is described in @ref{Widget
+Gallery}, and in more detail in every widget where it's relevant.
+@end defun
+
+There are other functions for creating widgets, useful when you work
+with composite widgets.  That is, widgets that are part of other
+widgets.
 
-Widgets are created with @code{widget-create}, which returns a
-@dfn{widget} object.  This object can be queried and manipulated by
-other widget functions, until it is deleted with @code{widget-delete}.
-After the widgets have been created, @code{widget-setup} must be called
-to enable them.
+@defun widget-create-child-and-convert parent type &rest args
+Create a widget of type @var{type} as a child of @var{parent}.
 
-@defun widget-create type [ keyword argument ]@dots{}
-Create and return a widget of type @var{type}.
-The syntax for the @var{type} argument is described in @ref{Basic Types}.
+Before creating it, converts @var{type} using the keyword arguments
+provided in @var{args}.
+@c FIXME: Is this description useful?
+Adds the @code{:indent} property, unless it is already present, and
+sets it to the sum of the values of: @code{:indent} and @code{:offset}
+from @var{parent} and @code{:extra-offset} from @var{type}.
 
-The keyword arguments can be used to overwrite the keyword arguments
-that are part of @var{type}.
+Returns a widget object, with the property @code{:parent} set to
+@var{PARENT}.
 @end defun
 
-@defun widget-delete widget
-Delete @var{widget} and remove it from the buffer.
+@defun widget-create-child parent type
+Create a widget of type @var{type} as a child of @var{parent}.
+
+This function is like @code{widget-create-child-and-convert} but it
+doesn't convert @var{type}, so it expects an already converted widget.
 @end defun
 
+@defun widget-create-child-value parent type value
+Create a widget of type @var{type} as a child of @var{parent} with
+value @var{value}.
+
+This function is like @code{widget-create-child}, but it lets you
+specify a value for the widget.
+
+Converts @var{value} to the internal format, as specified by
+@var{type}, and stores it into the @code{:value} property of @var{type}.
+That means, @var{value} should be in the external format, as
+specified by @var{type}.
+@end defun
+
+All these creating functions described here use the function stored in
+the @code{:create} property.  So, to modify the creation logic for a
+widget, you can provide a different @code{:create} function.
+
+When you're done creating widgets and you're ready for the user to
+interact with the buffer, use the function @code{widget-setup}.
+
 @defun widget-setup
-Set up a buffer to support widgets.
+Setup the current buffer, so that editable widgets can be edited.
 
 This should be called after creating all the widgets and before allowing
 the user to edit them.
 @end defun
 
-If you want to insert text outside the widgets in the form, the
-recommended way to do that is with @code{widget-insert}.
+As mentioned, all these functions return a widget object.  That widget
+object can be queried and manipulated with widget functions that
+take widgets as arguments, until deleting it with the widgets
+functions available to delete widgets.  Even if you don't save the
+returned widget object, you still can interact programmatically with
+the widget.  @xref{Working with Widgets}.
 
-@defun widget-insert
-Insert the arguments, either strings or characters, at point.
-The inserted text will be read-only.
+@defun widget-delete widget
+Delete the widget @var{widget} and remove it from the buffer.
 @end defun
 
-There is a standard widget keymap which you might find useful.
+@defun widget-children-value-delete widget
+Delete all children and buttons in widget @var{widget}.
 
-@findex widget-button-press
-@findex widget-button-click
-@defvr Const widget-keymap
-@key{TAB} and @kbd{C-@key{TAB}} are bound to @code{widget-forward} and
-@code{widget-backward}, respectively.  @key{RET} and @kbd{mouse-2}
-are bound to @code{widget-button-press} and
-@code{widget-button-click}.
-@end defvr
+This function does not delete @var{widget} itself, only the widgets
+stored in the @code{:children} and @code{:buttons} properties.  It
+also sets those properties to @code{nil}.
+@end defun
 
-@defvar widget-global-map
-Keymap used by @code{widget-button-press} and @code{widget-button-click}
-when not on a button.  By default this is @code{global-map}.
-@end defvar
+As with the creation mechanism, the function stored in @code{:delete}
+controls the deletion mechanism for a widget.
 
-@node Basic Types
-@chapter Basic Types
+Additionally, the library provides a way to make a copy of a widget.
 
-This is the general syntax of a type specification:
+@defun widget-copy widget
+Makes a copy of widget @var{widget} and returns it.
 
-@example
-@var{name} ::= (@var{name} [@var{keyword} @var{argument}]... @var{args})
-     |   @var{name}
-@end example
+It uses the function stored in the @code{:copy} property of @var{widget}
+and returns the widget that that function returns.
+@end defun
 
-Where, @var{name} is a widget name, @var{keyword} is the name of a
-property, @var{argument} is the value of the property, and @var{args}
-are interpreted in a widget specific way.
+As discussed, there is a conversion step when creating a widget.  To
+do the conversion without actually creating the widget, you can use
+the @code{widget-convert} function.
 
-@cindex keyword arguments
-The following keyword arguments apply to all widgets:
+@defun widget-convert type &rest args
+Convert @var{type} to a widget object, using keyword arguments @var{args}.
 
-@table @code
-@cindex internal format
-@cindex external format
-@vindex value@r{ keyword}
-@item :value
-The initial value for widgets of this type.  Typically, a widget
-represents its value in two formats: external and internal.  The
-external format is the value as the rest of Emacs sees it, and the
-internal format is a representation that the widget defines and uses
-in a widget specific way.
+Returns a widget object, suitable for creation.  It calls the function
+stored in the @code{:convert-widget} property, after putting into the
+@code{:args} property the arguments that the widget in question needs.
+If @var{type} has a @code{:value} property, either originally or after
+doing the conversion, this function converts the value stored in
+@code{:value} to the internal format, and stores it into @code{:value}.
+@end defun
 
-Both formats might be the same for certain widgets and might differ
-for others, and there is no guarantee about which format the value
-stored in the @code{:value} property has.  However, when creating a
-widget or defining a new one (@pxref{Defining New Widgets}), the
-@code{:value} should be in the external format.
+Apart from only creating widgets in the buffer, It's useful to have
+plain text.  For inserting text, the recommended way is with the
+@code{widget-insert} function.
 
-@vindex format@r{ keyword}
-@item :format
-This string will be inserted in the buffer when you create a widget.
-The following @samp{%} escapes are available:
+@defun widget-insert &rest args
+Insert @var{args}, either strings or characters, at point.
 
-@table @samp
-@item %[
-@itemx %]
-The text inside will be marked as a button.
+Uses @code{insert} to perform the insertion, passing @var{args} as
+argument.  @xref{Insertion,,,elisp, the Emacs Lisp Reference Manual},
+for more information about @var{args}.
 
-By default, the text will be shown in @code{widget-button-face}, and
-surrounded by brackets.
+The resulting text will be read-only.
+@end defun
 
-@defopt widget-button-prefix
-String to prefix buttons.
-@end defopt
+@node Working with Widgets
+@chapter Working with Widgets
+This section covers the more important functions needed to query and
+manipulate widgets in a generic way.  Widgets may have additional
+functions for interacting with them, those are described in the
+description for each widget.  @xref{Widget Gallery}.
 
-@defopt widget-button-suffix
-String to suffix buttons.
-@end defopt
+@defun widgetp widget
+Non-@code{nil} if @var{widget} is a widget.
+@end defun
 
-@item %@{
-@itemx %@}
-The text inside will be displayed with the face specified by
-@code{:sample-face}.
+@defun widget-type widget
+Return the type of widget @var{widget}, a symbol.
 
-@item %v
-This will be replaced with the buffer representation of the widget's
-value.  What this is depends on the widget type.
+This function is useful to find out which kind of widget @var{widget}
+represents, i.e., the name of the widget type when the widget
+was created.
+@end defun
 
-@strong{Warning:} In an @code{editable-field} widget, the @samp{%v} escape
-must be preceded by some other text in the format string (if specified).
+@defun widget-member widget property
+Non-@code{nil} if widget @var{widget} has a value (even @code{nil}) for
+property @var{property}.
+@end defun
 
-@item %d
-Insert the string specified by @code{:doc} here.
+@defun widget-get widget property
+For widget @var{widget}, return the value of the property @var{property}.
 
-@item %h
-Like @samp{%d}, with the following modifications: If the documentation
-string is more than one line, it will add a button which will toggle
-between showing only the first line, and showing the full text.
-Furthermore, if there is no @code{:doc} property in the widget, it will
-instead examine the @code{:documentation-property} property.  If it is a
-lambda expression, it will be called with the widget's value as an
-argument, and the result will be used as the documentation text.
+@var{property} should be a keyword, and the value is what was last set by
+@code{widget-put} for @var{property}.
+@end defun
 
-@item %t
-Insert the string specified by @code{:tag} here, or the @code{princ}
-representation of the value if there is no tag.
+@defun widget-put widget property value
+For widget @var{widget}, set the property @var{property} to @var{value}.
+@var{property} should be a keyword, while @var{value} can be anything.
+@end defun
 
-@item %%
-Insert a literal @samp{%}.
-@end table
+@defun widget-at &optional pos
+Return the widget at position @var{pos}, or at point if @var{pos} is @code{nil}.
+@end defun
 
-@vindex button-face@r{ keyword}
-@item :button-face
-Face used to highlight text inside %[ %] in the format.
+@defun widget-field-at pos
+Return the widget field at position POS, or @code{nil} if there is none.
+@end defun
 
-@vindex button-prefix@r{ keyword}
-@vindex button-suffix@r{ keyword}
-@item :button-prefix
-@itemx :button-suffix
-Text around %[ %] in the format.
+@defun widget-apply widget property &rest args
+Apply the function stored in @var{property} to @var{widget}, passing @var{args}
+as additional arguments to the function.
 
-These can be
-@table @emph
-@item nil
-No text is inserted.
+Returns the result of that function call.
+@end defun
 
-@item a string
-The string is inserted literally.
+@defun widget-value widget
+Return the current value contained in @var{widget}.
 
-@item a symbol
-The value of the symbol is expanded according to this table.
-@end table
+Note that the value returned by this function might differ from what's
+stored in the @code{:value} property of @var{widget}.  This is because
+this function extracts the current value of @var{widget} from the
+buffer, taking editions into account.
 
-@vindex doc@r{ keyword}
-@item :doc
-The string inserted by the @samp{%d} escape in the format
-string.
+The value returned is in the external format, after getting it with
+the @code{:value-get} function.
 
-@vindex tag@r{ keyword}
-@item :tag
-The string inserted by the @samp{%t} escape in the format
-string.
+It is an error to call this function on an uninitialized widget.
+@end defun
 
-@vindex tag-glyph@r{ keyword}
-@item :tag-glyph
-Name of image to use instead of the string specified by @code{:tag} on
-Emacsen that supports it.
+@defun widget-value-set widget value
+Set the value contained in @var{widget} to @var{value}.
 
-@vindex help-echo@r{ keyword}
-@item :help-echo
-Specifies how to display a message whenever you move to the widget with
-either @code{widget-forward} or @code{widget-backward} or move the mouse
-over it (using the standard @code{help-echo} mechanism).  The argument
-is either a string to display, a function of one argument, the widget,
-which should return a string to display, or a form that evaluates to
-such a string.
+Converts @var{value} to the internal format, and then sets it by
+applying the @code{:value-set} function.
 
-@vindex follow-link@r{ keyword}
-@item :follow-link
-Specifies how to interpret a @key{mouse-1} click on the widget.
-@xref{Clickable Text,, Defining Clickable Text, elisp, the Emacs Lisp Reference Manual}.
+It is an error to call this function with an invalid @var{value}, that
+is, a value that @var{widget} cannot represent.
+@end defun
 
-@vindex indent@r{ keyword}
-@item :indent
-An integer indicating the absolute number of spaces to indent children
-of this widget.
+@defun widget-default-get widget
+Return the default external value of widget @var{widget}.
 
-@vindex offset@r{ keyword}
-@item :offset
-An integer indicating how many extra spaces to add to the widget's
-grandchildren compared to this widget.
+The default value is the one stored in @code{:value} or the result of
+applying the @code{:default-get} function to the arguments of
+@var{widget}, as stored in @code{:args}.  A value of @code{nil} is
+ignored by default, so in order for a widget to respect @code{nil} as
+a value, it has to override the @code{:default-get} function.
+@end defun
 
-@vindex extra-offset@r{ keyword}
-@item :extra-offset
-An integer indicating how many extra spaces to add to the widget's
-children compared to this widget.
+@defun widget-type-default-get widget
+Convert the @code{:type} attribute in @var{widget} and return its
+default value.
+@end defun
 
-@vindex notify@r{ keyword}
-@item :notify
-A function called each time the widget or a nested widget is changed.
-The function is called with two or three arguments.  The first argument
-is the widget itself, the second argument is the widget that was
-changed, and the third argument is the event leading to the change, if
-any.
+@defun widget-child-value-get widget
+Return the value of the first member of @code{:children} in
+@var{widget}.
+@end defun
 
-@vindex menu-tag@r{ keyword}
-@item :menu-tag
-Tag used in the menu when the widget is used as an option in a
-@code{menu-choice} widget.
+@defun widget-child-value-inline widget
+Return the inline value of the first member of @code{:children} in
+@var{widget}.
 
-@vindex menu-tag-get@r{ keyword}
-@item :menu-tag-get
-Function used for finding the tag when the widget is used as an option
-in a @code{menu-choice} widget.  By default, the tag used will be either the
-@code{:menu-tag} or @code{:tag} property if present, or the @code{princ}
-representation of the @code{:value} property if not.
+The inline value is whatever the function stored in
+@code{:value-inline} returns.
+@end defun
 
-@vindex match@r{ keyword}
-@item :match
-Should be a function called with two arguments, the widget and an
-external value, and should return non-@code{nil} if the widget can
-represent the specified value.
+@defun widget-type-value-create widget
+Create a child widget for @var{widget}, of type stored in
+@code{:type}.
 
-@vindex validate@r{ keyword}
-@item :validate
-A function which takes a widget as an argument, and returns @code{nil}
-if the widget's current value is valid for the widget.  Otherwise it
-should return the widget containing the invalid data, and set that
-widget's @code{:error} property to a string explaining the error.
+Creates the child widget taking the value from the @code{:value}
+property and stores the newly created widget in the @code{:children}
+property of @var{widget}.
+
+The value stored in @code{:type} should be an unconverted widget
+type.
+@end defun
 
-The following predefined function can be used:
+@defun widget-value-convert-widget widget
+Initializes the @code{:value} property of @var{widget} from
+@code{:args}.
 
-@defun widget-children-validate widget
-All the @code{:children} of @var{widget} must be valid.
+Sets @code{:args} to @code{nil} and returns the modified widget
+@var{widget}.
 @end defun
 
-@vindex tab-order@r{ keyword}
-@item :tab-order
-Specify the order in which widgets are traversed with
-@code{widget-forward} or @code{widget-backward}.  This is only partially
-implemented.
+@defun widget-value-value-get widget
+Return the value stored in @code{:value} for widget @var{widget}.
 
-@enumerate a
-@item
-Widgets with tabbing order @code{-1} are ignored.
+This is different to getting the current value for @var{widget} with
+@code{widget-value}, since that function extracts the value from the
+buffer.
+@end defun
 
-@item
-(Unimplemented) When on a widget with tabbing order @var{n}, go to the
-next widget in the buffer with tabbing order @var{n+1} or @code{nil},
-whichever comes first.
+@defun widget-apply-action widget &optional event
+Apply the function stored in @code{:action} to @var{widget}, in
+response to @var{event}.
 
-@item
-When on a widget with no tabbing order specified, go to the next widget
+It is an error to call this function with an inactive widget.
+@end defun
+
+@defun widget-parent-action widget &optional event
+Tell @code{:parent} of @var{widget} to handle @var{event}.
+
+Optional @var{event} is the event that triggered the action.
+@end defun
+
+@defun widget-child-validate widget
+Check that the first member of @code{:children} in @var{widget} is valid.
+
+To be valid means that the widget value passes the checks that the
+function stored in @code{:validate} makes.
+@end defun
+
+@defun widget-children-validate widget
+Check that all @code{:children} in @var{widget} are valid.
+
+Returns @code{nil} on success, or the first child that isn't valid.
+@end defun
+
+@defun widget-type-match widget value
+Return non-@code{nil} if @var{VALUE} matches the value for the
+@code{:type} widget.
+
+As with the other type functions, the widget stored in @code{:type}
+should be an unconverted widget.
+@end defun
+
+@defun widget-types-copy widget
+Copy the @code{:args} value in @var{widget} and store them in @code{:args}.
+
+Makes the copies by calling @code{widget-copy} on each element present
+in @code{:args}.  Returns the modified widget @var{widget}.
+@end defun
+
+@defun widget-types-convert-widget widget
+Convert the @code{:args} value in @var{widget} and store them in
+@code{args}.
+
+Returns the modified widget @var{widget}.
+@end defun
+
+@node Widgets and the Buffer
+@chapter Widgets and the Buffer
+This chapter describes commands that are specific to buffers that
+contain widgets.
+
+@defvr Const widget-keymap
+Keymap containing useful bindings for buffers containing widgets.
+
+Binds @key{TAB} and @kbd{C-@key{TAB}} to @code{widget-forward} and
+@code{widget-backward}, respectively.  It also binds @key{RET} to
+@code{widget-button-press} and @kbd{down-mouse-1} and
+@kbd{down-mouse-2} to @code{widget-button-click}.
+@end defvr
+
+There's also a keymap for events that the widget library doesn't need
+to handle.
+
+@defvar widget-global-map
+Keymap used by @code{widget-button-press} and @code{widget-button-click}
+when not on a button.  By default this is @code{global-map}.
+@end defvar
+
+In addition to these two keymaps, each widget might define a keymap of
+its own, active when events happen at that widget.
+
+
+The following navigation commands are available:
+
+@table @kbd
+@item @key{TAB}
+@deffn Command widget-forward &optional count
+Move point @var{count} buttons or editing fields forward.
+@end deffn
+@item @kbd{M-@key{TAB}}
+@itemx @kbd{S-@key{TAB}}
+@deffn Command widget-backward &optional count
+Move point @var{count} buttons or editing fields backward.
+@end deffn
+@end table
+
+
+When editing an @code{editable-field} widget, the following commands
+are available:
+
+@table @kbd
+@item @key{C-e}
+@deffn Command widget-end-of-line
+Move point to the end of field or end of line, whichever is first.
+@end deffn
+
+@item @kbd{C-k}
+@deffn Command widget-kill-line
+Kill to end of field or end of line, whichever is first.
+@end deffn
+
+@item @kbd{M-TAB}
+@deffn Command widget-complete
+Complete the content of the editable field at point.
+@end deffn
+
+@item @kbd{C-m}
+@deffn Command widget-field-activate
+Invoke the editable field at point.
+@end deffn
+@end table
+
+The following two are commands that can execute widget actions.
+@table @kbd
+@item @key{RET}
+@findex widget-button-press
+@deffn Command widget-button-press @var{pos} &optional @var{event}
+Invoke the button at @var{pos}, defaulting to point.
+
+Invocation means to run the function stored in the @code{:action}
+property.
+
+If point is not located on a button, invoke the binding in
+@code{widget-global-map} (by default the global map).
+@end deffn
+
+@kindex mouse-2 @r{(on button widgets})
+@item mouse-2
+@findex widget-button-click
+@deffn Command widget-button-click @var{event}
+Invoke the button at the location of the mouse pointer.
+
+If the mouse pointer is located in an editable text field, invoke the
+binding in @code{widget-global-map} (by default the global map).
+
+In case the mouse-click is on a widget, calls the function stored in
+the @code{:mouse-down-action} property.
+@end deffn
+@end table
+
+@node Widget Gallery
+@chapter Widget Gallery
+@cindex widget syntax
+All widgets can be created from a type specification.  The general
+syntax of a type specification is:
+
+@c FIXME: Add BNF reference here? If yes, what reference?
+@example
+@var{name} ::= (@var{name} [@var{keyword} @var{argument}]... @var{args})
+     |   @var{name}
+@end example
+
+Where @var{name} is a widget name, as defined with
+@code{define-widget}, @var{keyword} is the name of a property and
+@var{argument} is the value for that property, and @var{args} are
+interpreted in a widget specific way.  @xref{Defining New Widgets}.
+
+The most basic widget in the Widget Library is the @dfn{default}
+widget.  It provides the basic behavior for all other widgets, and all
+its properties are present by default in derived widgets.  You're
+seldom (if ever) going to effectively create a default widget, but
+here we describe its properties and behavior, so that we can describe
+other widgets only by mentioning the properties and behavior those
+other widgets specialize.
+
+@deffn Widget default
+Widget used as a base for other widgets.
+
+It provides most of the functionality that is referred to as ``by
+default'' in this text.  If you want to define a new widget from
+scratch, use the @code{default} widget as its base.
+@end deffn
+
+@cindex keyword arguments
+The following keyword arguments apply to all widgets:
+
+@table @code
+@vindex create@r{ keyword}
+@item :create
+Function to create a widget from scratch.
+
+The function takes one argument, a widget type, and creates a widget
+of that type, inserts it in the buffer, and returns a widget object.
+
+By default, it inserts the widget at point, using the format provided
+in the @code{:format} property.
+
+@vindex delete@r{ keyword}
+@item :delete
+Function to delete a widget.
+
+The function should take one argument, a widget, and should remove all
+traces of the widget from the buffer.
+
+The default value is:
+
+@defun widget-default-delete widget
+Remove @var{widget} from the buffer.
+Delete all @code{:children} and @code{:buttons} in @var{widget}.
+@end defun
+
+In most cases you should not change this value, but instead use
+@code{:value-delete} to make any additional cleanup.
+
+@cindex internal format
+@cindex external format
+@vindex value@r{ keyword}
+@item :value
+The initial value for widgets of this type.
+
+Typically, a widget represents its value in two formats: external and
+internal.  The external format is the value as the rest of Emacs sees
+it, and the internal format is a representation that the widget
+defines and uses in a widget specific way.
+
+Both formats might be the same for certain widgets and might differ
+for others, and there is no guarantee about which format the value
+stored in the @code{:value} property has.  However, when creating a
+widget or defining a new one (@pxref{Defining New Widgets}), the
+@code{:value} should be in the external format.
+
+@vindex value-to-internal@r{ keyword}
+@item :value-to-internal
+Function to convert the value to the internal format.
+
+The function takes two arguments, a widget and an external value, and
+returns the internal value.  The function is called on the present
+@code{:value} when the widget is created, and on any value set later
+with @code{widget-value-set}.
+
+@vindex value-to-external@r{ keyword}
+@item :value-to-external
+Function to convert the value to the external format.
+
+The function takes two arguments, a widget and an internal value, and
+returns the value in the external format.
+
+@vindex value-create@r{ keyword}
+@item :value-create
+Function to expand the @samp{%v} escape in the format string.
+
+It will be called with the widget as its argument and should insert a
+representation of the widget's value in the buffer.
+
+@vindex value-delete@r{ keyword}
+@item :value-delete
+A function that should remove the representation of the widget's value
+from the buffer.
+
+It will be called with the widget as its argument.  It doesn't have to
+remove the text, but it should release markers and delete nested widgets
+if these are not listed in @code{:children} or @code{:buttons}.
+
+By default, it's a no-op.
+
+@vindex value-get@r{ keyword}
+@item :value-get
+Function to extract the value of a widget, as it is displayed in the
+buffer.
+
+@vindex value-set@r{ keyword}
+@item :value-set
+Function that takes a widget and a value as arguments, and recreates
+it.
+
+The value must already be in the internal format for widget.  By
+default, it deletes the widget with the @code{:delete} function and
+creates it again with the @code{:create} function.
+
+@vindex value-inline@r{ keyword}
+@item :value-inline
+Function that takes a widget and returns its value, inlined.
+
+Inlined means that if the widget is not inline (i.e., its
+@code{:inline} property is @code{nil}), the return value is wrapped in
+a list.
+
+@vindex default-get@r{ keyword}
+@item :default-get
+Function that takes a widget and returns its default value.
+
+By default, it just returns the value stored in @code{:value}.
+
+@vindex format@r{ keyword}
+@item :format
+This string will be inserted in the buffer when you create a widget.
+The following @samp{%} escapes are available:
+
+@table @samp
+@item %[
+@itemx %]
+The text inside will be marked as a button.
+
+By default, the text will be shown in @code{widget-button-face}, and
+surrounded by brackets.
+
+@item %@{
+@itemx %@}
+The text inside will be displayed with the face specified by
+@code{:sample-face}.
+
+@item %v
+This will be replaced with the buffer representation of the widget's
+value.  What this is depends on the widget type.
+
+@item %d
+Insert the string specified by @code{:doc} here.
+
+@item %h
+Like @samp{%d}, with the following modifications: If the documentation
+string is more than one line, it will add a button which will toggle
+between showing only the first line, and showing the full text.
+Furthermore, if there is no @code{:doc} property in the widget, it will
+instead examine the @code{:documentation-property} property.  If it is a
+lambda expression, it will be called with the widget's value as an
+argument, and the result will be used as the documentation text.
+
+@item %t
+Insert the string specified by @code{:tag} here, or the @code{princ}
+representation of the value if there is no tag.
+
+@item %%
+Insert a literal @samp{%}.
+@end table
+
+@vindex button-face@r{ keyword}
+@item :button-face
+Face used to highlight text inside %[ %] in the format.
+
+@vindex button-prefix@r{ keyword}
+@vindex button-suffix@r{ keyword}
+@item :button-prefix
+@itemx :button-suffix
+Strings used as prefix and suffix for widgets that are buttons.
+
+By default, the values are @code{widget-button-prefix} and
+@code{widget-button-suffix}.
+
+Text around %[ %] in the format.
+
+These can be
+@table @emph
+@item nil
+No text is inserted.
+
+@item a string
+The string is inserted literally.
+
+@item a symbol
+The value of the symbol is expanded according to this table.
+@end table
+
+@vindex doc@r{ keyword}
+@item :doc
+The string inserted by the @samp{%d} escape in the format
+string.
+
+@vindex tag@r{ keyword}
+@item :tag
+The string inserted by the @samp{%t} escape in the format
+string.
+
+@vindex tag-glyph@r{ keyword}
+@item :tag-glyph
+Name of image to use instead of the string specified by @code{:tag} on
+Emacsen that supports it.
+
+@vindex help-echo@r{ keyword}
+@item :help-echo
+Specifies how to display a message whenever you move to the widget with
+either @code{widget-forward} or @code{widget-backward} or move the mouse
+over it (using the standard @code{help-echo} mechanism).
+
+The value is either a string to display, or a function of one
+argument, the widget.  If a function, it should return a string to
+display, or a form that evaluates to such a string.
+
+@vindex follow-link@r{ keyword}
+@item :follow-link
+Specifies how to interpret a @key{mouse-1} click on the widget.
+@xref{Clickable Text,, Defining Clickable Text, elisp, the Emacs Lisp Reference Manual}.
+
+@vindex indent@r{ keyword}
+@item :indent
+An integer indicating the absolute number of spaces to indent children
+of this widget.  Its value might be @code{nil} too, which corresponds
+to a value of 0.
+
+The default @code{:create} functions and the functions that create the
+value per se use this property as a rudimentary layout mechanism for
+the widgets.
+
+@vindex offset@r{ keyword}
+@item :offset
+An integer indicating how many extra spaces to add to the widget's
+grandchildren compared to this widget.
+
+@vindex extra-offset@r{ keyword}
+@item :extra-offset
+An integer indicating how many extra spaces to add to the widget's
+children compared to this widget.
+
+@vindex menu-tag@r{ keyword}
+@item :menu-tag
+Tag used in the menu when the widget is used as an option in a
+@code{menu-choice} widget.
+
+@vindex menu-tag-get@r{ keyword}
+@item :menu-tag-get
+Function that takes a widget and returns the tag when the widget is
+used as an option in a @code{menu-choice} widget.
+
+By default, the tag used will be either the @code{:menu-tag} or
+@code{:tag} property if present, or the @code{princ} representation of
+the @code{:value} property if not.
+
+@vindex match@r{ keyword}
+@item :match
+Should be a function called with two arguments, the widget and an
+external value, and should return non-@code{nil} if the widget can
+represent the specified value.
+
+@vindex validate@r{ keyword}
+@item :validate
+A function which takes a widget as an argument, and returns @code{nil}
+if the widget's current value is valid for the widget.
+
+Otherwise, it should return the widget containing the invalid data,
+and set that widget's @code{:error} property to a string explaining
+the error.
+
+By default, it always returns @code{nil}.
+
+@vindex tab-order@r{ keyword}
+@item :tab-order
+Specify the order in which widgets are traversed with
+@code{widget-forward} or @code{widget-backward}.  This is only partially
+implemented.
+@enumerate a
+@item
+Widgets with tabbing order @code{-1} are ignored.
+
+@item
+(Unimplemented) When on a widget with tabbing order @var{n}, go to the
+next widget in the buffer with tabbing order @var{n+1} or @code{nil},
+whichever comes first.
+
+@item
+When on a widget with no tabbing order specified, go to the next widget
 in the buffer with a positive tabbing order, or @code{nil}
 @end enumerate
 
@@ -683,46 +1165,249 @@ Basic Types
 The parent of a nested widget (e.g., a @code{menu-choice} item or an
 element of a @code{editable-list} widget).
 
-@vindex sibling-args@r{ keyword}
-@item :sibling-args
-This keyword is only used for members of a @code{radio-button-choice} or
-@code{checklist}.  The value should be a list of extra keyword
-arguments, which will be used when creating the @code{radio-button} or
-@code{checkbox} associated with this item.
+@vindex sibling-args@r{ keyword}
+@item :sibling-args
+This keyword is only used for members of a @code{radio-button-choice} or
+@code{checklist}.  The value should be a list of extra keyword
+arguments, which will be used when creating the @code{radio-button} or
+@code{checkbox} associated with this item.
+
+@vindex completions-function@r{ keyword}
+@item :completions-function
+Function that takes a widget and returns completion data for that
+widget, like @code{completion-at-point-functions} would.
+@xref{Completion,,,elisp, the Emacs Lisp Reference Manual}.  It's
+used by @code{editable-field} widgets to provide completions.
+
+By default, it looks into the property @code{:completions}, which
+should be a completion table.  If @code{:completions} is @code{nil},
+then it calls the function stored either in the @code{:complete} or
+@code{:complete-function} property.
+
+@vindex format-handler@r{ keyword}
+@item :format-handler
+Function to handle unknown @samp{%} escapes in the format string.
+
+It takes a widget and the character that follows the @samp{%} as
+arguments.  You can set this to allow your widget to handle
+non-standard escapes in your own specialized widgets.
+
+@findex widget-default-format-handler
+You should end up calling @code{widget-default-format-handler} to handle
+unknown escape sequences, which will handle the @samp{%h} and any future
+escape sequences, as well as give an error for unknown escapes.
+
+@vindex button-face-get@r{ keyword}
+@item :button-face-get
+Function to return the face used to fontify a widget button.
+
+Takes a widget and returns an appropriate face for the widget.  By
+default, it either returns the face stored in the @code{:button-face}
+property, or calls the @code{:button-face-get} function from the
+parent of the widget, if it has one.
+
+@vindex mouse-face-get@r{ keyword}
+@item :mouse-face-get
+Function to return the face used to fontify a widget when the mouse
+pointer hovers over it.
+
+Takes a widget and returns an appropriate face.  By default, it either
+returns the face stored in the @code{:mouse-face} property, or calls
+the @code{:button-face-get} function from the parent of the widget, if
+it has one.
+
+@vindex copy@r{ keyword}
+@item :copy
+Function to deep copy a widget type.
+
+It takes a shallow copy of the widget type as an argument (made by
+@code{copy-sequence}), and returns a deep copy.  The purpose of this
+is to avoid having different instances of combined widgets share
+nested attributes.
+
+Its value by default is @code{identity}.
+
+@vindex active@r{ keyword}
+@item :active
+Function that takes a widget and returns @code{t} if it is active.
+
+A widget might be effectively always active, if its
+@code{:always-active} property is @code{t}.
+
+@cindex active widget
+@cindex inactive widget
+@cindex activate a widget
+@cindex deactivate a widget
+Widgets can be in two states: active, which means they are modifiable by
+the user, or inactive, which means they cannot be modified by the user.
+You can query or set the state with the following code:
+
+@lisp
+;; Examine if @var{widget} is active or not.
+(if (widget-apply @var{widget} :active)
+    (message "Widget is active.")
+  (message "Widget is inactive.")
+
+;; Make @var{widget} inactive.
+(widget-apply @var{widget} :deactivate)
+
+;; Make @var{widget} active.
+(widget-apply @var{widget} :activate)
+@end lisp
+
+A widget is inactive if it, or any of its ancestors (found by
+following the @code{:parent} link), have been deactivated.  To make sure
+a widget is really active, you must therefore activate both it and
+all its ancestors.
+
+@lisp
+(while widget
+  (widget-apply widget :activate)
+  (setq widget (widget-get widget :parent)))
+@end lisp
+
+You can check if a widget has been made inactive by examining the value
+of the @code{:inactive} keyword.  If this is non-@code{nil}, the widget itself
+has been deactivated.  This is different from using the @code{:active}
+keyword, in that the latter tells you if the widget @strong{or} any of
+its ancestors have been deactivated.  Do not attempt to set the
+@code{:inactive} keyword directly.  Use the @code{:activate}
+@code{:deactivate} functions instead.
+
+@vindex activate@r{ keyword}
+@item :activate
+Function that takes a widget and makes it active for user
+modifications.
+
+@vindex deactivate@r{ keyword}
+@item :deactivate
+Function that takes a widget and makes it inactive for user
+modifications.
+
+@vindex action@r{ keyword}
+@item :action
+Function that takes a widget and optionally an event, and handles a
+user initiated event.
+
+By default, uses the @code{:notify} function to notify the widget's
+parent about the event.
+
+@vindex mouse-down-action@r{ keyword}
+@item :mouse-down-action
+Function that takes a widget and optionally an event, and handles a
+mouse click on the widget.
+
+By default, it does nothing.
+
+@vindex notify@r{ keyword}
+@item :notify
+A function called each time the widget or a nested widget is changed.
+
+The function is called with two or three arguments.  The first argument
+is the widget itself, the second argument is the widget that was
+changed, and the third argument is the event leading to the change, if
+any.
+
+By default, it passes the notification to the widget's parent.
+
+@vindex prompt-value@r{ keyword}
+@item :prompt-value
+Function to prompt for a value in the minibuffer.
+
+The function should take four arguments, a widget, a prompt (a
+string), a value and a boolean, and should return a value for the
+widget, entered by the user.
 
-@end table
+The prompt is the prompt to use.  The value is the default value to
+use, unless the fourtha argument is non-@code{nil}, in which case
+there is no default value.
 
-@deffn {User Option} widget-image-directory
-Directory where Widget should look for images.
-Widget will look here for a file with the same name as specified for the
-image, with either a @file{.xpm} (if supported) or @file{.xbm} extension.
-@end deffn
+The function should read the value using the method most natural for
+this widget, and does not have to check that it matches.
+@end table
 
-@deffn{User Option} widget-image-enable
-If non-@code{nil}, allow images to appear on displays where they are supported.
-@end deffn
+@menu
+* Basic Types::
+* Sexp Types::
+@end menu
 
+@node Basic Types
+@section Basic Types
 
 @menu
+* item::
 * link::
 * url-link::
 * info-link::
+* function-link::
+* variable-link::
+* face-link::
+* file-link::
+* emacs-library-link::
+* emacs-commentary-link::
 * push-button::
 * editable-field::
 * text::
 * menu-choice::
 * radio-button-choice::
-* item::
 * choice-item::
 * toggle::
+* radio-button-toggle::
 * checkbox::
 * checklist::
 * editable-list::
 * group::
+* documentation-string::
 @end menu
 
+@node item
+@subsection The @code{item} Widget
+@findex item@r{ widget}
+
+Syntax:
+
+@example
+@var{type} ::= (item [@var{keyword} @var{argument}]... @var{value})
+@end example
+
+A useful widget that holds a constant value, and can be included in
+other widgets.  Its super is the @code{default} widget.
+
+As can be seen in the syntax, the @code{item} widget is one of the
+widget that handles the @var{args} argument to @code{widget-create} in
+a specific way.  If present, @var{value} is used to initialize the
+@code{:value} property.  When created, it inserts the value as a
+string in the buffer.
+
+By default, it has the following properties:
+
+@table @code
+@item :convert-widget
+The function that allows it to handle @var{value}.
+
+@item :value-create
+Prints the representation of @code{:value} in the buffer.
+
+@item :value-get
+Returns the value stored in @code{:value}.
+
+@item :match
+A value matches the @code{item} widget if it's @code{equal} to its
+@code{:value}.
+
+@item :match-inline
+Inline values match the @code{item} widget if @code{:value} is a
+sublist of values.
+
+@item :action
+The @code{item} widget notifies itself of an event.
+
+@item :format
+By default, the @code{item} widget inserts its tag in the buffer.
+@end table
+
 @node link
-@section The @code{link} Widget
+@subsection The @code{link} Widget
 @findex link@r{ widget}
 
 Syntax:
@@ -731,22 +1416,42 @@ link
 @var{type} ::= (link [@var{keyword} @var{argument}]...  [ @var{value} ])
 @end example
 
+A widget to represent an embedded link.  Its super is the @code{item}
+widget.
+
 The @var{value}, if present, is used to initialize the @code{:value}
 property.  The value should be a string, which will be inserted in the
 buffer.
 
-By default the link will be shown in brackets.
+By default, it has the following properties:
 
-@defopt widget-link-prefix
-String to prefix links.
-@end defopt
+@table @code
+@item :button-prefix
+The value of @code{widget-link-prefix}.
 
-@defopt widget-link-suffix
-String to suffix links.
-@end defopt
+@item :button-suffix
+The value of @code{widget-link-suffix}.
+
+@item :keymap
+A custom keymap for the link widget, so that it can respond to mouse clicks.
+
+@item :follow-link
+This property allows the link to respect the value of
+@code{mouse-1-click-follows-link}.  @xref{Clickable Text,,,elisp, the Emacs Lisp Reference Manual}.
+
+@item :format
+Buttonizes the link, to make it clickable.
+
+If you override this property, you should make sure to provide the
+@samp{%[} and @samp{%]} escape sequences, so that the link is
+clickable.
+
+@end table
+
+By default the link will be shown in brackets.
 
 @node url-link
-@section The @code{url-link} Widget
+@subsection The @code{url-link} Widget
 @findex url-link@r{ widget}
 
 Syntax:
@@ -755,12 +1460,14 @@ url-link
 @var{type} ::= (url-link [@var{keyword} @var{argument}]...  @var{url})
 @end example
 
-@findex browse-url-browser-function@r{, and @code{url-link} widget}
-When this link is invoked, the @acronym{WWW} browser specified by
-@code{browse-url-browser-function} will be called with @var{url}.
+A widget to represent a link to a web page.  Its super is the
+@code{link} widget.
+
+It overrides the @code{:action} property to open up the @var{url}
+specified.
 
 @node info-link
-@section The @code{info-link} Widget
+@subsection The @code{info-link} Widget
 @findex info-link@r{ widget}
 
 Syntax:
@@ -769,11 +1476,104 @@ info-link
 @var{type} ::= (info-link [@var{keyword} @var{argument}]...  @var{address})
 @end example
 
-When this link is invoked, the built-in Info reader is started on
-@var{address}.
+A widget to represent a link to an info file.  Its super is the
+@code{link} widget.
+
+It overrides the @code{:action} property, to a function to start the
+built-in Info reader on @var{address}, when invoked.
+
+@node function-link
+@subsection The @code{function-link} Widget
+@findex function-link@r{ widget}
+Syntax:
+
+@example
+@var{type} ::= (function-link [@var{keyword} @var{argument}]...  @var{function})
+@end example
+
+A widget to represent a link to an Emacs function.  Its super is the
+@code{link} widget.
+
+It overrides the @code{:action} property, to a function to describe
+@var{function}.
+
+@node variable-link
+@subsection The @code{variable-link} Widget
+@findex variable-link@r{ widget}
+Syntax:
+
+@example
+@var{type} ::= (variable-link [@var{keyword} @var{argument}]...  @var{var})
+@end example
+
+A widget to represent a link to an Emacs variable.  Its super is the
+@code{link} widget.
+
+It overrides the @code{:action} property, to a function to describe
+@var{var}.
+
+@node face-link
+@subsection The @code{face-link} Widget
+@findex face-link@r{ widget}
+Syntax:
+
+@example
+@var{type} ::= (face-link [@var{keyword} @var{argument}]...  @var{face})
+@end example
+
+A widget to represent a link to an Emacs face.  Its super is the
+@code{link} widget.
+
+It overrides the @code{:action} property, to a function to describe
+@var{face}.
+
+@node file-link
+@subsection The @code{file-link} Widget
+@findex file-link@r{ widget}
+Syntax:
+
+@example
+@var{type} ::= (file-link [@var{keyword} @var{argument}]...  @var{file})
+@end example
+
+A widget to represent a link to a file.  Its super is the
+@code{link} widget.
+
+It overrides the @code{:action} property, to a function to find the file
+@var{file}.
+
+@node emacs-library-link
+@subsection The @code{emacs-library-link} Widget
+@findex emacs-library-link@r{ widget}
+Syntax:
+
+@example
+@var{type} ::= (emacs-library-link [@var{keyword} @var{argument}]...  @var{file})
+@end example
+
+A widget to represent a link to an Emacs Lisp file.  Its super is the
+@code{link} widget.
+
+It overrides the @code{:action} property, to a function to find the file
+@var{file}.
+
+@node emacs-commentary-link
+@subsection The @code{emacs-commentary-link} Widget
+@findex emacs-commentary-link@r{ widget}
+Syntax:
+
+@example
+@var{type} ::= (emacs-commentary-link [@var{keyword} @var{argument}]...  @var{file})
+@end example
+
+A widget to represent a link to the Comment section of an Emacs Lisp
+file.  Its super is the @code{link} widget.
+
+It overrides the @code{:action} property, to a function to find the file
+@var{file} and put point in the Comment section.
 
 @node  push-button
-@section The @code{push-button} Widget
+@subsection The @code{push-button} Widget
 @findex push-button@r{ widget}
 
 Syntax:
@@ -782,22 +1582,37 @@ push-button
 @var{type} ::= (push-button [@var{keyword} @var{argument}]...  [ @var{value} ])
 @end example
 
+A widget that acts as a pushable button.  Its super is the @code{item}
+widget.
+
 The @var{value}, if present, is used to initialize the @code{:value}
 property.  The value should be a string, which will be inserted in the
 buffer.
 
-By default the tag will be shown in brackets.
+By default, it has the following properties:
+@table @code
+@item :button-prefix
+The empty string.
 
-@defopt widget-push-button-prefix
-String to prefix push buttons.
-@end defopt
+@item :button-suffix
+The empty string.
 
-@defopt widget-push-button-suffix
-String to suffix push buttons.
-@end defopt
+@item :value-create
+Inserts a representation of the ``on'' and ``off'' states for the push
+button.
+
+The representation might be an image, stored in the @code{:tag-glyph}
+property, or text.  If it is text, it might be the value of the
+@code{:tag} property, or the @code{:value} of the widget, surrounded
+with @code{widget-push-button-prefix} and
+@code{widget-push-button-suffix}.  @xref{Customization}.
+
+@item :format
+Buttonizes the widget, to make it clickable.
+@end table
 
 @node editable-field
-@section The @code{editable-field} Widget
+@subsection The @code{editable-field} Widget
 @findex editable-field@r{ widget}
 
 Syntax:
@@ -806,56 +1621,137 @@ editable-field
 @var{type} ::= (editable-field [@var{keyword} @var{argument}]... [ @var{value} ])
 @end example
 
+A widget that can be edited by the user.  Its super is the
+@code{default} widget.
+
 The @var{value}, if present, is used to initialize the @code{:value}
 property.  The value should be a string, which will be inserted in the
-field.  This widget will match all string values.
+field.  If not present, @code{:value} is the empty string.
+
+@strong{Warning:} In an @code{editable-field} widget, the editable
+field must not be adjacent to another widget---that won't work.
+You must put some text in between.  Either make this text part of
+the @code{editable-field} widget itself, or insert it with
+@code{widget-insert}.
 
-The following extra properties are recognized:
+This widget either overrides or adds the following properties:
 
 @table @code
+@item :convert-widget
+Just like the @code{item} widget, this function allows it to
+initialize @code{:value} from @var{value}.
+
+@vindex keymap@r{ keyword}
+@vindex widget-field-keymap
+@item :keymap
+Keymap used in the editable field.
+
+The default value is @code{widget-field-keymap}, which allows the user
+to use all the normal editing commands, even if the buffer's major
+mode suppresses some of them.  Pressing @key{RET} invokes the function
+specified by @code{:action}.
+
+@item :format
+By default, it specifies to insert only the widget's value.
+
+@strong{Warning:} In an @code{editable-field} widget, the @samp{%v} escape
+must be preceded by some other text in the @code{:format} string (if
+specified).
+
 @vindex size@r{ keyword}
 @item :size
-The width of the editable field.@*
+The width of the editable field.
+
 By default the field will reach to the end of the line.
 
 @vindex value-face@r{ keyword}
 @item :value-face
-Face used for highlighting the editable field.  Default is
-@code{widget-field-face}, see @ref{User Interface}.
+Face used for highlighting the editable field.
+
+Default is @code{widget-field-face}, @pxref{User Interface}.
 
 @vindex secret@r{ keyword}
 @item :secret
-Character used to display the value.  You can set this to, e.g., @code{?*}
-if the field contains a password or other secret information.  By
-default, this is @code{nil}, and the value is not secret.
+Character used to display the value.
+
+You can set this to, e.g., @code{?*} if the field contains a password
+or other secret information.  By default, this is @code{nil}, and the
+value is not secret.
 
 @vindex valid-regexp@r{ keyword}
 @item :valid-regexp
 By default the @code{:validate} function will match the content of the
-field with the value of this attribute.  The default value is @code{""}
-which matches everything.
+field with the value of this attribute.
 
-@vindex keymap@r{ keyword}
-@vindex widget-field-keymap
-@item :keymap
-Keymap used in the editable field.  The default value is
-@code{widget-field-keymap}, which allows you to use all the normal
-editing commands, even if the buffer's major mode suppresses some of
-them.  Pressing @key{RET} invokes the function specified by
-@code{:action}.
+The default value is @code{""} which matches everything.
+
+@item :validate
+Returns @code{nil} if the current value of the widget matches the
+@code{:valid-regexp} value.
+
+@item :prompt-internal
+A function to read a value for widget, used by the
+@code{:prompt-value} function.
+
+@item :prompt-history
+A variable that holds the history of field minibuffer edits.
+
+@item :prompt-value
+A function that uses the @code{:prompt-internal} function and the
+@code{:prompt-history} value to prompt for a string, and retun the
+user response in the external format.
+
+@item :action
+When invoked, moves point to the next field.
+
+@item :value-create
+Function that takes care of creating the widget, respecting its
+@code{:size} and @code{:value}.
+
+@item :value-set
+Function to use to modify programatically the current value of the
+widget.
+
+@item :value-delete
+Function that removes the widget so it cannot be edited anymore.
+
+@item :value-get
+Function to return the current text in the widget.
+
+It takes an optional argument, @var{no-truncate}.  If
+@var{no-truncate} is nil, truncates trailing spaces.
+
+@item :match
+Function that makes the widget match any string value.
 @end table
 
 @node text
-@section The @code{text} Widget
+@subsection The @code{text} Widget
 @findex text@r{ widget}
 
+Syntax:
+
+@example
+@var{type} ::= (text [@var{keyword} @var{argument}]... [ @var{value} ])
+@end example
+
+A widget just like the @code{editable-field} widget, but intended for
+multiline text fields.  Its super is the @code{editable-field} widget.
+
+It overrides the following properties:
+
+@table @code
+@item :format
+By default, prints a tag and the value.
+
 @vindex widget-text-keymap
-This is just like @code{editable-field}, but intended for multiline text
-fields.  The default @code{:keymap} is @code{widget-text-keymap}, which
-does not rebind the @key{RET} key.
+@item :keymap
+The default is @code{widget-text-keymap}, which does not rebind the
+@key{RET} key.
+@end table
 
 @node menu-choice
-@section The @code{menu-choice} Widget
+@subsection The @code{menu-choice} Widget
 @findex menu-choice@r{ widget}
 
 Syntax:
@@ -864,21 +1760,37 @@ menu-choice
 @var{type} ::= (menu-choice [@var{keyword} @var{argument}]... @var{type} ... )
 @end example
 
+A widget to represent a menu of options.  Its super is the
+@code{default} widget.
+
 The @var{type} argument represents each possible choice.  The widget's
-value will be that of the chosen @var{type} argument.  This widget will
-match any value matching at least one of the specified @var{type}
-arguments.
+value will be that of the chosen @var{type} argument.
+
+It either overrides or adds the following properties:
 
 @table @code
+@item :convert-widget
+A function that takes care of converting each possible choice.
+
+@item :copy
+A function to copy each possible choice.
+
+@item :format
+By default, buttonize the tag and show the value.
+
 @vindex void@r{ keyword}
 @item :void
 Widget type used as a fallback when the value does not match any of the
 specified @var{type} arguments.
 
+By default this is an @code{item} widget.
+
 @vindex case-fold@r{ keyword}
 @item :case-fold
-Set this to @code{nil} if you don't want to ignore case when prompting for a
-choice through the minibuffer.
+If @code{nil} don't ignore case when prompting for a choice through
+the minibuffer.
+
+By default, its value is @code{t}.
 
 @vindex children@r{ keyword}
 @item :children
@@ -892,10 +1804,54 @@ menu-choice
 @vindex args@r{ keyword}
 @item :args
 The list of types.
+
+@item :value-create
+The function that inserts the current value for the widget.
+
+It inserts the first choice that matches, as with the @code{:match}
+function, the value of the widget.
+
+@item :value-get
+Returns the value of the first child for the widget (see the
+description for @code{:children} above).
+
+@item :value-inline
+Returns the inline value of the first child for the widget.
+
+@item :default-get
+The default value for this widget is the default value for the first
+choice, in case @code{:value} is missing.
+
+This means that if you want a specific default value for the
+@code{menu-choice} widget, you should either pass a @code{:value}
+property when creating it, or arrange the choices so that the first
+one can hold your desired default value.
+
+@item :mouse-down-action
+A function that takes care of showing a menu, if possible and desired.
+
+@item :action
+A function that takes care of getting a new choice for the widget.
+
+Depending on the number of choices available, it may show a menu or
+just toggle the choices, or even do nothing at all.
+
+After getting the choice, it recreates the widget and notifies it.
+
+@item :validate
+Returns @code{nil} if the widget's value is a valid choice.
+
+@item :match
+This widget will match any value matching at least one of the
+specified @var{type} arguments.
+
+@item :match-inline
+A function that returns non-@code{nil} if the values match the widget,
+taking into account the @code{:inline} property.
 @end table
 
 @node radio-button-choice
-@section The @code{radio-button-choice} Widget
+@subsection The @code{radio-button-choice} Widget
 @findex radio-button-choice@r{ widget}
 
 Syntax:
@@ -904,14 +1860,28 @@ radio-button-choice
 @var{type} ::= (radio-button-choice [@var{keyword} @var{argument}]...  @var{type} ... )
 @end example
 
-The component types specify the choices, with one radio button for
+A widget to represent a choice from multiple options.  Its super is
+the @code{default} widget.
+
+The component @var{types} specify the choices, with one radio button for
 each.  The widget's value will be that of the chosen @var{type}
-argument.  This widget matches any value that matches at least one of
-the specified @var{type} arguments.
+argument.
 
-The following extra properties are recognized.
+It overrides the following properties:
 
 @table @code
+@item :convert-widget
+As other composite widgets, a function that takes care of converting
+each available choice.
+
+@item :copy
+A function to copy each available choice.
+
+@item :action
+A function that checks if any radio button was pressed and activates
+the pressed one, possibly deactivating an old one.  Then, it notifies
+itself.
+
 @vindex entry-format@r{ keyword}
 @item :entry-format
 This string will be inserted for each entry in the list.
@@ -925,6 +1895,9 @@ radio-button-choice
 Insert a literal @samp{%}.
 @end table
 
+@item :format
+By default, it inserts its value.
+
 @vindex button-args@r{ keyword}
 @item :button-args
 A list of keywords to pass to the radio buttons.  Useful for setting,
@@ -940,42 +1913,55 @@ radio-button-choice
 
 @vindex choice@r{ keyword}
 @item :choice
-The current chosen type
+The current chosen type.
 
 @vindex args@r{ keyword}
 @item :args
 The list of types.
-@end table
 
-You can add extra radio button items to a @code{radio-button-choice}
-widget after it has been created with the function
-@code{widget-radio-add-item}.
+@item :value-create
+A function to insert all available choices.
 
-@defun widget-radio-add-item widget type
-Add to @code{radio-button-choice} widget @var{widget} a new radio button
-item of type @var{type}.
-@end defun
+@item :value-get
+Returns the value for the chosen widget.
 
-Please note that such items added after the @code{radio-button-choice}
-widget has been created will @strong{not} be properly destructed when
-you call @code{widget-delete}.
+@item :value-set
+A function to set the value to one of its available options.
 
-@node item
-@section The @code{item} Widget
-@findex item@r{ widget}
+@item :value-inline
+A function that returns the inline value of the child widget.
 
-Syntax:
+@item :offset
+By default, this widget has an offset of 4.
 
-@example
-@var{item} ::= (item [@var{keyword} @var{argument}]... @var{value})
-@end example
+@item :validate
+The widget validates if the current value is valid for one of its
+children.
+
+@item :match
+This widget matches any value that matches at least one of
+the specified @var{type} arguments.
+
+@item :match-inline
+Like the @code{:match} function, but taking into account inline
+values.
+@end table
+
+You can add extra radio button items to a @code{radio-button-choice}
+widget after it has been created with the function
+@code{widget-radio-add-item}.
+
+@defun widget-radio-add-item widget type
+Add to @code{radio-button-choice} widget @var{widget} a new radio button
+item of type @var{type}.
+@end defun
 
-The @var{value}, if present, is used to initialize the @code{:value}
-property.  The value should be a string, which will be inserted in the
-buffer.  This widget will only match the specified value.
+Please note that such items added after the @code{radio-button-choice}
+widget has been created will @strong{not} be properly destructed when
+you call @code{widget-delete}.
 
 @node choice-item
-@section The @code{choice-item} Widget
+@subsection The @code{choice-item} Widget
 @findex choice-item@r{ widget}
 
 Syntax:
@@ -984,14 +1970,26 @@ choice-item
 @var{item} ::= (choice-item [@var{keyword} @var{argument}]... @var{value})
 @end example
 
+A widget to represent a choice in a @code{menu-choice} widget.  Its
+super is the @code{item} widget.
+
 The @var{value}, if present, is used to initialize the @code{:value}
-property.  The value should be a string, which will be inserted in the
-buffer as a button.  Activating the button of a @code{choice-item} is
-equivalent to activating the parent widget.  This widget will only match
-the specified value.
+property.
+
+It overrides the following properties:
+
+@table @code
+@item :action
+Activating the button of a @code{choice-item} is equivalent to
+activating the parent widget.
+
+@item :format
+By default, it buttonizes the tag (i.e., its value) and adds a newline
+character at the end of the widget.
+@end table
 
 @node toggle
-@section The @code{toggle} Widget
+@subsection The @code{toggle} Widget
 @findex toggle@r{ widget}
 
 Syntax:
@@ -1000,43 +1998,136 @@ toggle
 @var{type} ::= (toggle [@var{keyword} @var{argument}]...)
 @end example
 
+A widget that can toggle between two states.  Its super is the
+@code{item} widget.
+
 The widget has two possible states, @samp{on} and @samp{off}, which
 correspond to a @code{t} or @code{nil} value, respectively.
 
-The following extra properties are recognized:
+It either overrides or adds the following properties:
 
 @table @code
+@item :format
+By default, it buttonizes the value and adds a newline at the end of
+the widget.
+
 @item :on
 A string representing the @samp{on} state.  By default the string
 @samp{on}.
+
 @item :off
 A string representing the @samp{off} state.  By default the string
 @samp{off}.
+
 @vindex on-glyph@r{ keyword}
 @item :on-glyph
 Name of a glyph to be used instead of the @samp{:on} text string, on
 emacsen that supports this.
+
 @vindex off-glyph@r{ keyword}
 @item :off-glyph
 Name of a glyph to be used instead of the @samp{:off} text string, on
 emacsen that supports this.
+
+@item :value-create
+A function for creating the widget's value, according to its
+@samp{:on} or @samp{:off} state.
+
+@item :action
+Function to toggle the state of the widget.  After toggling, it
+notifies itself.
+
+@item :match
+This widget matches anything.
+@end table
+
+@node radio-button-toggle
+@subsection The @code{radio-button-toggle} Widget
+@findex radio-button-toggle@r{ widget}
+Syntax:
+
+@example
+@var{type} ::= (radio-button-toggle [@var{keyword} @var{argument}]...)
+@end example
+
+A toggle to use in the @code{radio} widget.
+
+It overrides the following properties:
+
+@table @code
+@item :button-prefix
+The empty string.
+
+@item :button-suffix
+The empty string.
+
+@item :on
+The string ``(*)'', to represent the @samp{on} state.
+
+@item :off
+The string ``( )'', to represent the @samp{off} state.
+
+@item :on-glyph
+The name of an image to represent the @samp{on} state.
+
+@item :off-glpyh
+The name of an image to represent the @samp{off} state.
+
+@item :format
+By default, it buttonizes its value.
+
+@item :notify
+A function to notify its parent.
 @end table
 
 @node checkbox
-@section The @code{checkbox} Widget
+@subsection The @code{checkbox} Widget
 @findex checkbox@r{ widget}
 
-This widget has two possible states, @samp{selected} and
-@samp{unselected}, which corresponds to a @code{t} or @code{nil} value.
-
 Syntax:
 
 @example
 @var{type} ::= (checkbox [@var{keyword} @var{argument}]...)
 @end example
 
+A widget to represent a toggle widget, with a checkbox.  Its super is
+the @code{toggle} widget.
+
+This widget has two possible states, @samp{selected} and
+@samp{unselected}, which corresponds to a @code{t} or @code{nil}
+value, respectively.
+
+It either overrides or adds the following properties:
+
+@table @code
+@item :button-prefix
+The empty string.
+
+@item :button-suffix
+The empty string.
+
+@item :format
+By default, buttonizes the value.
+
+@item :on
+By default, the string ``[X]''.
+
+@item :off
+By default, the string ``[ ]''.
+
+@item :on-glyph
+The name of the image to use when the state is @samp{on}.
+
+@item :off-glyph
+The name of the image to use when the state is @samp{off}.
+
+@item :action
+A function that toggles the checkbox, notifies the parents and in the
+@samp{on} state, activates its siblings.
+@end table
+
 @node checklist
-@section The @code{checklist} Widget
+@subsection The @code{checklist} Widget
 @findex checklist@r{ widget}
 
 Syntax:
@@ -1045,14 +2136,26 @@ checklist
 @var{type} ::= (checklist [@var{keyword} @var{argument}]...  @var{type} ... )
 @end example
 
+A widget to represent a multiplice choice.  Its super is the
+@code{default} widget.
+
 The @var{type} arguments represent each checklist item.  The widget's
 value will be a list containing the values of all checked @var{type}
-arguments.  The checklist widget will match a list whose elements all
-match at least one of the specified @var{type} arguments.
+arguments.
 
-The following extra properties are recognized:
+It either overrides or adds the following properties:
 
 @table @code
+@item :convert-widget
+As other composite widgets, a function that takes care of converting
+each checklist item.
+
+@item :copy
+A function to copy each checklist item.
+
+@item :format
+By default, it inserts its value.
+
 @vindex entry-format@r{ keyword}
 @item :entry-format
 This string will be inserted for each entry in the list.
@@ -1066,14 +2169,6 @@ checklist
 Insert a literal @samp{%}.
 @end table
 
-@vindex greedy@r{ keyword}
-@item :greedy
-Usually a checklist will only match if the items are in the exact
-sequence given in the specification.  By setting @code{:greedy} to
-non-@code{nil}, it will allow the items to come in any sequence.
-However, if you extract the value they will be in the sequence given
-in the checklist, i.e., the original sequence is forgotten.
-
 @vindex button-args@r{ keyword}
 @item :button-args
 A list of keywords to pass to the checkboxes.  Useful for setting,
@@ -1090,10 +2185,35 @@ checklist
 @vindex args@r{ keyword}
 @item :args
 The list of types.
+
+@item :value-create
+The function that takes care of inserting all values.
+
+@item :value-get
+A function that returns all values of selected items.
+
+@item :validate
+A function that ensures all selected children are valid.
+
+@item :match
+The checklist widget will match a list whose elements all
+match at least one of the specified @var{type} arguments.
+
+@item :match-inline
+Like the @code{:match} function, but taking into account the
+@code{:inline} property.
+
+@vindex greedy@r{ keyword}
+@item :greedy
+Usually a checklist will only match if the items are in the exact
+sequence given in the specification.  By setting @code{:greedy} to
+non-@code{nil}, it will allow the items to come in any sequence.
+However, if you extract the value they will be in the sequence given
+in the checklist, i.e., the original sequence is forgotten.
 @end table
 
 @node editable-list
-@section The @code{editable-list} Widget
+@subsection The @code{editable-list} Widget
 @findex editable-list@r{ widget}
 
 Syntax:
@@ -1102,12 +2222,19 @@ editable-list
 @var{type} ::= (editable-list [@var{keyword} @var{argument}]... @var{type})
 @end example
 
-The value is a list, where each member represents one widget of type
-@var{type}.
+A widget that can hold a variable list of widgets of the same type,
+represented by @var{type}.  Its super is the @code{default} widget.
 
-The following extra properties are recognized:
+It either overrides or adds the following properties:
 
 @table @code
+@item :convert-widget
+As other composite widgets, a function that takes care of converting
+each type in @var{type}.
+
+@item :copy
+A function to copy the types given in @var{type}.
+
 @vindex entry-format@r{ keyword}
 @item :entry-format
 This string will be inserted for each entry in the list.
@@ -1117,9 +2244,9 @@ editable-list
 This will be replaced with the buffer representation of the @var{type}
 widget.
 @item %i
-Insert the @b{[INS]} button.
+Insert the @b{[INS]} button, a widget of type @code{insert-button}.
 @item %d
-Insert the @b{[DEL]} button.
+Insert the @b{[DEL]} button, a widget of type @code{delete-button}.
 @item %%
 Insert a literal @samp{%}.
 @end table
@@ -1140,6 +2267,18 @@ editable-list
 @item :buttons
 The widgets representing the insert and delete buttons.
 
+@item :format
+By default, insert its value and at the and adds an insert button.
+
+This is useful so that new elements can be added to the list upon user
+request.
+
+@item :format-handler
+A function that recognize the escape for inserting an insert button.
+
+@item :offset
+By default, this widget has an offset of 12.
+
 @vindex children@r{ keyword}
 @item :children
 The widgets representing the elements of the list.
@@ -1147,24 +2286,124 @@ editable-list
 @vindex args@r{ keyword}
 @item :args
 List whose @sc{car} is the type of the list elements.
+
+@item :insert-before
+Function to insert a new widget as a child of the @code{editable-list}
+widget.
+
+This function inserts a recently deleted child, if there is one.  That
+is useful, so that the user can move elements in a list easily.  If
+there is not a recently deleted child, it inserts a child with its
+default value.
+
+@item :delete-at
+Function to delete a child from the widget, and store it into the
+@code{:last-deleted} list, so that it can be reinserted when the
+@code{:insert-before} function executes.
+
+@item :value-create
+The function that takes care of inserting all values.
+
+@item :value-get
+Function that returns a list with the value of the child widgets.
+
+@item :validate
+This widget validates if all children validate.
+
+@item :match
+To match, the value must be a list and all the list members must match
+the specified @var{type}.
+
+@item :match-inline
+Like the @code{:match} function, but taking into account inline
+values and widgets.
 @end table
 
 @node group
-@section The @code{group} Widget
+@subsection The @code{group} Widget
 @findex group@r{ widget}
 
-This widget simply group other widgets together.
-
 Syntax:
 
 @example
 @var{type} ::= (group [@var{keyword} @var{argument}]... @var{type}...)
 @end example
 
-The value is a list, with one member for each @var{type}.
+A widget to group other widgets.  Its super is the @code{default}
+widget.
+
+Its value is a list, with one member for each @var{type}.
+
+It overrides the following properties:
+
+@table @code
+@item :convert-widget
+As other composite widgets, a function that takes care of converting
+each widget in @var{type}.
+
+@item :copy
+A function to copy the types given in @var{type}.
+
+@item :format
+By default, displays a newline character and its value.
+
+@item :value-create
+A function to create each of its components.
+
+@item :value-get
+The same function used by the @code{editable-list} widget.
+
+@item :default-get
+A function that returns a list whose members are the default values of
+each widget it groups.
+
+@item :validate
+This widget validates if all of its children validate.
+
+@item :match
+This widget matches a value that matches each of its components.
+
+@item :match-inline
+As @code{:match}, but taking into account widgets and values that are
+inline.
+@end table
+
+@node documentation-string
+@subsection The @code{documentation-string} Widget
+@findex documentation-string@r{ widget}
+Syntax:
+
+@example
+@var{type} ::= (documentation-string [@var{keyword} @var{argument}]... @var{value})
+@end example
+
+A widget to represent a documentation string.  Its super is the
+@code{item} widget.
+
+It either overrides or adds the following properties:
+
+@table @code
+@item :format
+By default, insert its value.
+
+@item :value-create
+Function to insert a documentation string, possibly hiding part of the
+documentation if its large.
+
+To show or hide the rest of the documentation, uses a
+@code{visibility} widget.
+
+@item :action
+Function to toggle showing the documentation upon an event.
+
+@item :visibility-widget
+A symbol, the type of the widget to use for the visibility widget.
+
+This is, by default, the symbol @code{visibility}.
+@end table
 
 @node Sexp Types
-@chapter Sexp Types
+@section Sexp Types
 @cindex sexp types
 
 A number of widgets for editing @dfn{s-expressions} (Lisp types), sexp
@@ -1179,7 +2418,7 @@ Sexp Types
 @end menu
 
 @node constants
-@section The Constant Widgets
+@subsection The Constant Widgets
 @cindex constant widgets
 
 The @code{const} widget can contain any Lisp expression, but the user is
@@ -1192,19 +2431,26 @@ constants
 @var{type} ::= (const [@var{keyword} @var{argument}]...  [ @var{value} ])
 @end example
 
-The @var{value}, if present, is used to initialize the @code{:value}
-property and can be any s-expression.
+Its super is the @code{item} widget.  The @var{value}, if present, is
+used to initialize the @code{:value} property and can be any
+s-expression.
 
 @deffn Widget const
 This will display any valid s-expression in an immutable part of the
 buffer.
+
+It overrides the @code{:prompt-value} function, to avoid prompting and
+just return the widget's value.
 @end deffn
 
 There are two variations of the @code{const} widget, namely
 @code{variable-item} and @code{function-item}.  These should contain a
-symbol with a variable or function binding.  The major difference from
-the @code{const} widget is that they will allow the user to see the
-variable or function documentation for the symbol.
+symbol with a variable or function binding, respectively.  The major
+difference from the @code{const} widget is that they will allow the
+user to see the variable or function documentation for the symbol.
+
+This is accomplished via using the @samp{%h} format escape, and adding
+an appropiate @code{:documentation-property} function for each widget.
 
 @deffn Widget variable-item
 An immutable symbol that is bound as a variable.
@@ -1215,7 +2461,7 @@ constants
 @end deffn
 
 @node generic
-@section Generic Sexp Widget
+@subsection Generic Sexp Widget
 @cindex generic sexp widget
 
 The @code{sexp} widget can contain any Lisp expression, and allows the
@@ -1228,23 +2474,42 @@ generic
 @end example
 
 @deffn Widget sexp
-This will allow you to edit any valid s-expression in an editable buffer
-field.
+This widget represents an editable field that's useful to edit any
+valid s-expression.
 
 The @code{sexp} widget takes the same keyword arguments as the
 @code{editable-field} widget.  @xref{editable-field}.
+
+Its default value is @code{nil}.
+@end deffn
+
+@deffn Widget restricted-sexp
+A widget to edit Lisp expressions restricted to certain values or
+types.  Its super is the @code{sexp} widget.
+
+It works just like the sexp widget, but it overrides the @code{:match}
+function to match for certain values.  To use this widget, either you
+must define a @code{:match} function or give a
+@code{:match-alternatives} property.  The @code{:match-alternatives}
+property holds a list of predicate functions to call when checking if
+a given value matches the widget.  Each predicate function will be
+called with one argument, the value to be matched, and should return
+non-@code{nil} on success.
+
+As an example, the @code{integer} widget overrides
+@code{:match-alternatives} to @code{(integerp)}.
 @end deffn
 
 @node atoms
-@section Atomic Sexp Widgets
+@subsection Atomic Sexp Widgets
 @cindex atomic sexp widget
 
 The atoms are s-expressions that do not consist of other s-expressions.
 For example, a string, a file name, or a symbol are atoms, while a list
 is a composite type.  You can edit the value of an atom with the
-following widgets.
+widgets described in this section.
 
-The syntax for all the atoms are:
+The syntax for all the atoms is:
 
 @example
 @var{type} ::= (@var{construct} [@var{keyword} @var{argument}]...  [ @var{value} ])
@@ -1252,68 +2517,151 @@ atoms
 
 The @var{value}, if present, is used to initialize the @code{:value}
 property and must be an expression of the same type as the widget.
-That is, the string widget can only be initialized with a string.
+That is, for example, the string widget can only be initialized with a
+string.
 
 All the atom widgets take the same keyword arguments as the
 @code{editable-field} widget.  @xref{editable-field}.
 
 @deffn Widget string
-Allows you to edit a string in an editable field.
+An editable field widget that can represent any Lisp string.
+
+It offers completion via the ispell library and the @code{:complete}
+property.
 @end deffn
 
 @deffn Widget regexp
-Allows you to edit a regular expression in an editable field.
+An editable field widget that can represent a regular expression.
+
+Overrides the @code{:match} and the @code{:validate} properties to
+check that the value is a valid regexp.
 @end deffn
 
 @deffn Widget character
-Allows you to enter a character in an editable field.
+An editable field widget that can represent a character.
+
+The character widget represents some characters (like the newline
+character) in a special manner, to make it easier for the user to see
+what's the content of the character field.
 @end deffn
 
 @deffn Widget file
-Allows you to edit a file name in an editable field.
+A widget for editing file names.
 
 Keywords:
 @table @code
+@item :completions
+Offers file name completion to the user.
+
+@item :prompt-value
+A function to read a file name from the minibuffer.
+
 @vindex must-match@r{ keyword}
 @item :must-match
-If this is set to non-@code{nil}, only existing file names will be
-allowed in the minibuffer.
+If this is set to non-@code{nil}, only existing file names are allowed
+when prompting for a value in the minibuffer.
+
+@item :match
+The widget matches if the value is a string, and the file whose name
+is that string is an existing file, or if @code{:must-match} is
+@code{nil}.
+
+@item :validate
+The widget is valid if its value matches.
+
 @end table
 @end deffn
 
 @deffn Widget directory
-Allows you to edit a directory name in an editable field.
-Similar to the @code{file} widget.
+A widget for editing directory names.
+
+Its super is the @code{file} widget, and it overrides the
+@code{:completions} property, to offer completions only for
+directories.
 @end deffn
 
 @deffn Widget symbol
-Allows you to edit a Lisp symbol in an editable field.
+A widget for editing a Lisp symbol.
+
+Its value by default is @code{nil}.
 @end deffn
 
 @deffn Widget function
-Allows you to edit a lambda expression, or a function name with completion.
+A widget for editing a lambda expression, or a function name, offering
+completion.  Its super is the @code{restricted-sexp} widget.
 @end deffn
 
 @deffn Widget variable
-Allows you to edit a variable name, with completion.
+A widget for editing variable names, offering completion.  Its super
+is the @code{symbol} widget.
 @end deffn
 
 @deffn Widget integer
-Allows you to edit an integer in an editable field.
+A widget for editing integers in an editable field.  Its super is the
+@code{restricted-sexp} widget.
+
+It has a default @code{:value} of 0.
+@end deffn
+
+@deffn Widget natnum
+A widget for editing non-negative integers.  Its super is the
+@code{restricted-sexp} widget.
+
+It has a default @code{:value} of 0.
+@end deffn
+
+@deffn Widget float
+A widget for editing a floating point number.  Its super is the
+@code{restricted-sexp} widget.
+
+It has a default @code{:value} of 0.0.
 @end deffn
 
 @deffn Widget number
-Allows you to edit a number in an editable field.
+A widget for editing a number, either floating point or integer.  Its
+super is the @code{restricted-sexp} widget.
+
+It has a default @code{:value} of 0.0.
 @end deffn
 
 @deffn Widget boolean
-Allows you to edit a boolean.  In Lisp this means a variable which is
-either @code{nil} meaning false, or non-@code{nil} meaning true.
+A widget for editing a boolean value.  Its super is the @code{toggle}
+widget.
+
+Its value may be @code{nil}, meaning false, or non-@code{nil}, meaning
+true.
+@end deffn
+
+@deffn Widget color
+A widget to edit a color name.
+
+In addition, shows a sample that shows the selected color, if any.
 @end deffn
 
+@deffn Widget other
+A widget useful as the last item in a @code{choice} widget, since it
+matches any value.
+
+Its super is the @code{sexp} widget, and its @code{:value} is
+@code{other}, by default.
+@end deffn
+
+@deffn Widget coding-system
+A widget that can represent a coding system name, offering
+completions.  @xref{Coding Systems,,,elisp, the Emacs Lisp Reference
+Manual}.  Its super is the @code{symbol} widget.
+
+It has a default value of @code{undecided}.
+@end deffn
+
+@deffn Widget key
+A widget to represent a key sequence.
+
+It uses a special keymap as the @code{:keymap}.
+@end deffn
 
 @node composite
-@section Composite Sexp Widgets
+@subsection Composite Sexp Widgets
 @cindex composite sexp widgets
 
 The syntax for the composite widget construct is:
@@ -1327,6 +2675,9 @@ composite
 will be displayed in the buffer, and will be editable by the user.
 
 @deffn Widget cons
+A widget to edit cons-cell values.  Its super is the @code{group}
+widget.
+
 The value of a @code{cons} widget must be a cons-cell whose @sc{car}
 and @sc{cdr} have two specified types.  It uses this syntax:
 
@@ -1336,8 +2687,10 @@ composite
 @end deffn
 
 @deffn Widget choice
-The value matched by a @code{choice} widget must have one of a fixed
-set of types.  The widget's syntax is as follows:
+A widget to hold a value of one of a fixed set of types.  Its super is
+the @code{menu-choice} widget.
+
+The widget's syntax is as follows:
 
 @example
 @var{type} ::= (choice [@var{keyword} @var{argument}]...  @var{type} ... )
@@ -1345,9 +2698,19 @@ composite
 
 The value of a @code{choice} widget can be anything that matches any of the
 @var{types}.
+
+This widget only displays the widget that corresponds to the current
+choice.
+@end deffn
+
+@deffn Widget radio
+A widget to hold a value of one of a fixed set of options.  Its super is
+the @code{radio-button-choice} widget.
 @end deffn
 
 @deffn Widget list
+A widget to edit a list value.  Its super is the @code{group} widget.
+
 The value of a @code{list} widget must be a list whose element types
 match the specified component types:
 
@@ -1355,15 +2718,18 @@ composite
 @var{type} ::= (list [@var{keyword} @var{argument}]...  @var{component-type}...)
 @end example
 
-Thus, @code{(list string number)} matches lists of two elements,
-the first being a string and the second being a number.
+Thus, for example, @code{(list string number)} matches lists of two
+elements, the first being a string and the second being a number.
 @end deffn
 
 @deffn Widget vector
+A widget to edit a vector value.  Its super is the @code{group}
+widget.
+
 The @code{vector} widget is like the @code{list} widget but matches
-vectors instead of lists.  Thus, @code{(vector string number)} matches
-vectors of two elements, the first being a string and the second being
-a number.
+vectors instead of lists.  Thus, for example, @code{(vector string
+number)} matches vectors of two elements, the first being a string and
+the second being a number.
 @end deffn
 
 The above suffice for specifying fixed size lists and vectors.  To get
@@ -1392,126 +2758,74 @@ composite
 trying to explain it here, I'll just suggest you meditate over it for
 a while.
 
-@deffn Widget set
-Specifies a type whose values are the lists whose elements all belong
-to a given set.  The order of elements of the list is not significant.
-Here's the syntax:
-
-@example
-@var{type} ::= (set [@var{keyword} @var{argument}]...  @var{permitted-element} ... )
-@end example
-
-Use @code{const} to specify each permitted element, like this:
-@code{(set (const a) (const b))}.
-@end deffn
-
-@deffn Widget repeat
-Specifies a list of any number of elements that fit a certain type.
-
-@example
-@var{type} ::= (repeat [@var{keyword} @var{argument}]...  @var{type})
-@end example
-@end deffn
-
-@node Widget Properties
-@chapter Properties
-@cindex properties of widgets
-@cindex widget properties
-
-You can examine or set the value of a widget by using the widget object
-that was returned by @code{widget-create}.
-
-@defun widget-value widget
-Return the current value contained in @var{widget}.
-It is an error to call this function on an uninitialized widget.
-@end defun
-
-@defun widget-value-set widget value
-Set the value contained in @var{widget} to @var{value}.
-It is an error to call this function with an invalid @var{value}.
-@end defun
-
-@strong{Important:} You @emph{must} call @code{widget-setup} after
-modifying the value of a widget before the user is allowed to edit the
-widget again.  It is enough to call @code{widget-setup} once if you
-modify multiple widgets.  This is currently only necessary if the widget
-contains an editing field, but may be necessary for other widgets in the
-future.
+@deffn Widget set
+A widget to hold a list of members from a fixed set.  Its super is the
+@code{checklist} widget.
 
-If your application needs to associate some information with the widget
-objects, for example a reference to the item being edited, it can be
-done with @code{widget-put} and @code{widget-get}.  The property names
-must begin with a @samp{:}.
+Its value is a list where the elements all belong to a given set.  The
+order of elements of the list is not significant.
 
-@defun widget-put widget property value
-In @var{widget} set @var{property} to @var{value}.
-@var{property} should be a symbol, while @var{value} can be anything.
-@end defun
+Here's the syntax:
 
-@defun widget-get widget property
-In @var{widget} return the value for @var{property}.
-@var{property} should be a symbol, the value is what was last set by
-@code{widget-put} for @var{property}.
-@end defun
+@example
+@var{type} ::= (set [@var{keyword} @var{argument}]...  @var{permitted-element} ... )
+@end example
 
-@defun widget-member widget property
-Non-@code{nil} if @var{widget} has a value (even @code{nil}) for
-property @var{property}.
-@end defun
+Use @code{const} to specify each permitted element, like this:
+@code{(set (const a) (const b))}.
+@end deffn
 
-@defun widget-apply widget property &rest args
-Apply the value of @var{property} to @var{widget}, passing @var{args}
-as additional arguments to the function.  Return the result of that
-function call.
-@end defun
+@deffn Widget repeat
+Specifies a list of any number of elements that fit a certain type.
+Its super is the @code{editable-list} widget.
 
-Occasionally it can be useful to know which kind of widget you have,
-i.e., the name of the widget type you gave when the widget was created.
+@example
+@var{type} ::= (repeat [@var{keyword} @var{argument}]...  @var{type})
+@end example
+@end deffn
 
-@defun widget-type widget
-Return the name of @var{widget}, a symbol.
-@end defun
+@deffn Widget plist
+A widget to edit property lists.  Its super is the @code{list} widget.
 
-@cindex active widget
-@cindex inactive widget
-@cindex activate a widget
-@cindex deactivate a widget
-Widgets can be in two states: active, which means they are modifiable by
-the user, or inactive, which means they cannot be modified by the user.
-You can query or set the state with the following code:
+It recognizes the following properties:
 
-@lisp
-;; Examine if @var{widget} is active or not.
-(if (widget-apply @var{widget} :active)
-    (message "Widget is active.")
-  (message "Widget is inactive.")
+@table @code
+@item :options
+A given set of recommended key-value values for the @code{plist}
+widget.  Each option shows up as a checklist item.
 
-;; Make @var{widget} inactive.
-(widget-apply @var{widget} :deactivate)
+@item :key-type
+The widget type to use for the plist keys.  By default, it uses the
+@code{symbol} widget.
 
-;; Make @var{widget} active.
-(widget-apply @var{widget} :activate)
-@end lisp
+@item :value-type
+The widget type to use for the plist values.  By default, it uses the
+@code{sexp} widget.
+@end table
+@end deffn
 
-A widget is inactive if it, or any of its ancestors (found by
-following the @code{:parent} link), have been deactivated.  To make sure
-a widget is really active, you must therefore activate both it and
-all its ancestors.
+@deffn Widget alist
+A widget to edit association lists.  Its super is the @code{list}
+widget.
 
-@lisp
-(while widget
-  (widget-apply widget :activate)
-  (setq widget (widget-get widget :parent)))
-@end lisp
+It recognizes the same properties that the @code{plist} widget, with
+the difference that the @code{:key-type} uses by default a @code{sexp}
+widget.
+@end deffn
 
-You can check if a widget has been made inactive by examining the value
-of the @code{:inactive} keyword.  If this is non-@code{nil}, the widget itself
-has been deactivated.  This is different from using the @code{:active}
-keyword, in that the latter tells you if the widget @strong{or} any of
-its ancestors have been deactivated.  Do not attempt to set the
-@code{:inactive} keyword directly.  Use the @code{:activate}
-@code{:deactivate} keywords instead.
+Most composite widgets do not allow for recursion.  That is, none of
+the contained widgets may be of the same type that is currently being
+defined.  To allow for this kind of widgets, there's the @code{lazy}
+widget.
+
+@deffn Widget lazy
+A base widget for recursive data structures.  Its super is the
+@code{default} widget.
 
+When instantiated, it contains a single inferior widget of the widget
+type specified in the @code{:type} property.  Its value is the same as
+the value of this inferior widget.
+@end deffn
 
 @node Defining New Widgets
 @chapter Defining New Widgets
@@ -1520,19 +2834,27 @@ Defining New Widgets
 
 You can define specialized widgets with @code{define-widget}.  It allows
 you to create a shorthand for more complex widgets, including specifying
-component widgets and new default values for the keyword
-arguments.
+component widgets and new default values for the keyword arguments.
 
 @defun define-widget name class doc &rest args
-Define a new widget type named @var{name} from @code{class}.
+Define a new widget type named @var{name} that derives from @var{class}.
 
-@var{name} and class should both be symbols, @code{class} should be one
-of the existing widget types.
+@var{name} and @var{class} should both be symbols, and @var{class}
+should be one of the existing widget types.
 
 The third argument @var{doc} is a documentation string for the widget.
 
-After the new widget has been defined, the following two calls will
-create identical widgets:
+@var{args} should be key-value pairs, overriding keyword values of
+@var{class}, or adding new recognized keywords for @var{name}.
+
+Usually, you'll want to derive from an existing widget type, like the
+@code{editable-field} widget, or the @code{default} widget, but it's
+also possible to derive from nothing, by passing a value of @code{nil}
+as @var{class}.  Note that if you do this, you're entirely responsible
+for defining a whole new default behavior for your widgets.
+
+After using this function, the following two calls will create
+identical widgets:
 
 @itemize @bullet
 @item
@@ -1555,170 +2877,67 @@ Defining New Widgets
 If you only want to specify defaults for keywords with no complex
 conversions, you can use @code{identity} as your conversion function.
 
-The following additional keyword arguments are useful when defining new
-widgets:
+When defining new widgets, the @code{:convert-widget} property might
+be useful:
+
 @table @code
 @vindex convert-widget@r{ keyword}
 @item :convert-widget
 Function to convert a widget type before creating a widget of that
-type.  It takes a widget type as an argument, and returns the converted
-widget type.  When a widget is created, this function is called for the
-widget type and all the widget's parent types, most derived first.
-
-The following predefined functions can be used here:
-
-@defun widget-types-convert-widget widget
-Convert @code{:args} as widget types in @var{widget}.
-@end defun
-
-@defun widget-value-convert-widget widget
-Initialize @code{:value} from @code{:args} in @var{widget}.
-@end defun
-
-@vindex copy@r{ keyword}
-@item :copy
-Function to deep copy a widget type.  It takes a shallow copy of the
-widget type as an argument (made by @code{copy-sequence}), and returns a
-deep copy.  The purpose of this is to avoid having different instances
-of combined widgets share nested attributes.
-
-The following predefined functions can be used here:
-
-@defun widget-types-copy widget
-Copy @code{:args} as widget types in @var{widget}.
-@end defun
-
-@vindex value-to-internal@r{ keyword}
-@item :value-to-internal
-Function to convert the value to the internal format.  The function
-takes two arguments, a widget and an external value, and returns the
-internal value.  The function is called on the present @code{:value}
-when the widget is created, and on any value set later with
-@code{widget-value-set}.
-
-@vindex value-to-external@r{ keyword}
-@item :value-to-external
-Function to convert the value to the external format.  The function
-takes two arguments, a widget and an internal value, and returns the
-external value.
-
-@vindex create@r{ keyword}
-@item :create
-Function to create a widget from scratch.  The function takes one
-argument, a widget type, and creates a widget of that type, inserts it
-in the buffer, and returns a widget object.
-
-@vindex delete@r{ keyword}
-@item :delete
-Function to delete a widget.  The function takes one argument, a widget,
-and should remove all traces of the widget from the buffer.
-
-The default value is:
-
-@defun widget-default-delete widget
-Remove @var{widget} from the buffer.
-Delete all @code{:children} and @code{:buttons} in @var{widget}.
-@end defun
-
-In most cases you should not change this value, but instead use
-@code{:value-delete} to make any additional cleanup.
-
-@vindex value-create@r{ keyword}
-@item :value-create
-Function to expand the @samp{%v} escape in the format string.  It will
-be called with the widget as its argument and should insert a
-representation of the widget's value in the buffer.
-
-Nested widgets should be listed in @code{:children} or @code{:buttons}
-to make sure they are automatically deleted.
-
-@vindex value-delete@r{ keyword}
-@item :value-delete
-Should remove the representation of the widget's value from the buffer.
-It will be called with the widget as its argument.  It doesn't have to
-remove the text, but it should release markers and delete nested widgets
-if these are not listed in @code{:children} or @code{:buttons}.
-
-@vindex value-get@r{ keyword}
-@item :value-get
-Function to extract the value of a widget, as it is displayed in the
-buffer.
-
-The following predefined function can be used here:
-
-@defun widget-value-value-get widget
-Return the @code{:value} property of @var{widget}.
-@end defun
-
-@vindex format-handler@r{ keyword}
-@item :format-handler
-Function to handle unknown @samp{%} escapes in the format string.  It
-will be called with the widget and the character that follows the
-@samp{%} as arguments.  You can set this to allow your widget to handle
-non-standard escapes.
-
-@findex widget-default-format-handler
-You should end up calling @code{widget-default-format-handler} to handle
-unknown escape sequences, which will handle the @samp{%h} and any future
-escape sequences, as well as give an error for unknown escapes.
-
-@vindex action@r{ keyword}
-@item :action
-Function to handle user initiated events.  By default, @code{:notify}
-the parent.
+type.
 
-The following predefined function can be used here:
-
-@defun widget-parent-action widget &optional event
-Tell @code{:parent} of @var{widget} to handle the @code{:action}.
-Optional @var{event} is the event that triggered the action.
-@end defun
+It takes a widget type as an argument, and returns the converted
+widget type.  When a widget is created, this function is called for
+the widget type and all the widget's parent types, most derived first.
 
-@vindex prompt-value@r{ keyword}
-@item :prompt-value
-Function to prompt for a value in the minibuffer.  The function should
-take four arguments, @var{widget}, @var{prompt}, @var{value}, and
-@var{unbound} and should return a value for widget entered by the user.
-@var{prompt} is the prompt to use.  @var{value} is the default value to
-use, unless @var{unbound} is non-@code{nil}, in which case there is no default
-value.  The function should read the value using the method most natural
-for this widget, and does not have to check that it matches.
+The predefined functions @code{widget-types-convert-widget} and
+@code{widget-value-convert-widget} can be used here.
 @end table
 
-If you want to define a new widget from scratch, use the @code{default}
-widget as its base.
-
-@deffn Widget default
-Widget used as a base for other widgets.
-
-It provides most of the functionality that is referred to as ``by
-default'' in this text.
-@end deffn
-
-@node Widget Browser
-@chapter Widget Browser
+@node Inspecting Widgets
+@chapter Inspecting Widgets
 @cindex widget browser
 
-There is a separate package to browse widgets.  This is intended to help
-programmers who want to examine the content of a widget.  The browser
-shows the value of each keyword, but uses links for certain keywords
-such as @samp{:parent}, which avoids printing cyclic structures.
+There is a separate package to browse widgets, in
+@samp{wid-browse.el}.  This is intended to help programmers who want
+to examine the content of a widget.  The browser shows the value of
+each keyword, but uses links for certain keywords such as
+@samp{:parent}, which avoids printing cyclic structures.
 
 @deffn Command widget-browse @var{widget}
 Create a widget browser for @var{widget}.
+
 When called interactively, prompt for @var{widget}.
 @end deffn
 
 @deffn Command widget-browse-other-window @var{widget}
 Create a widget browser for @var{widget} and show it in another window.
+
 When called interactively, prompt for @var{widget}.
 @end deffn
 
 @deffn Command widget-browse-at @var{pos}
 Create a widget browser for the widget at @var{pos}.
+
 When called interactively, use the position of point.
 @end deffn
 
+In addition, there's a function to describe the widget at point.
+
+@deffn Command widget-describe &optional widget-or-pos
+Describe the widget at point.
+
+When called from Lisp, @var{widget-or-pos} might be the widget to
+describe or a buffer position where a widget is present.  If
+@var{widget-or-pos} is @code{nil}, the widget to describe is the
+widget at point.
+
+This command sets up a help buffer for providing information about the
+widget, mainly its @code{:action} and @code{:mouse-down-action}
+functions, and provides links to describe it in more detail using the
+@code{widget-browse} commands described above.
+@end deffn
+
 @node  Widget Minor Mode
 @chapter Widget Minor Mode
 @cindex widget minor mode
@@ -1740,14 +2959,24 @@ Utilities
 @chapter Utilities
 @cindex utility functions for widgets
 
+Here we describe some utility functions that don't really have a place
+earlier in this manual.
+
 @defun widget-prompt-value widget prompt [ value unbound ]
 Prompt for a value matching @var{widget}, using @var{prompt}.
 The current value is assumed to be @var{value}, unless @var{unbound} is
 non-@code{nil}.
+
+Converts @var{widget} before prompting, and for prompting it uses the
+@code{:prompt-value} function.  This function returns the user
+``answer'', and it's an error if that answer doesn't match the widget,
+as with the @code{:match} function.
+
+If the answer matches the widget, returns the answer.
 @end defun
 
 @defun widget-get-sibling widget
-Get the item which @var{widget} is assumed to toggle.
+Get the item which @var{widget} should toggle.
 This is only meaningful for radio buttons or checkboxes in a list.
 @end defun
 
@@ -1773,6 +3002,142 @@ Utilities
 then the return value is the @var{value} of the chosen element.
 @end defun
 
+@defun widget-image-find image
+Create a graphical button from @var{image}, an image or a file name
+sans extension.
+
+If @var{image} is a file name, the file should be in
+@code{widget-image-directory}, or in a place where @code{find-image}
+will find it.
+@end defun
+
+@defun widget-image-insert widget tag image
+As part of @var{widget}, insert the text @var{tag} or, if supported,
+the image @var{image}.
+
+@var{image} should be as described in @code{widget-image-find}.
+@end defun
+
+@defun widget-echo-help pos
+Display help-echo text for the widget at @var{pos}.
+
+Uses the value of @code{:help-echo}.  If it is a function, it calls it
+to get a string.  Otherwise, it @code{eval}s it.
+@end defun
+
+@node  Customization
+@chapter Customization
+This chapter is about the customization options for the Widget
+library, for the end user.
+
+@deffn Face widget-field-face
+Face used for other editing fields.
+@end deffn
+
+@deffn Face widget-button-face
+Face used for buttons.
+@end deffn
+
+@defopt widget-mouse-face
+Face used for highlighting a button when the mouse pointer moves
+across it.
+
+The default value is @code{highlight}.
+@end defopt
+
+@defopt widget-image-directory
+Directory where Widget should look for images.
+
+Widget will look here for a file with the same name as specified for the
+image, with either a @file{.xpm} (if supported) or @file{.xbm} extension.
+@end defopt
+
+@defopt widget-image-enable
+If non-@code{nil}, allow images to appear on displays where they are supported.
+@end defopt
+
+@defopt widget-image-conversion
+An alist to convert symbols from image formats to file name suffixes.
+
+Each element is a cons cell (@var{format} . @var{suffix}), where
+@var{format} is a symbol that represents an image format and
+@var{suffix} is its correspondent suffix.
+@end defopt
+
+@defopt widget-button-prefix
+String to prefix buttons.
+@end defopt
+
+@defopt widget-button-suffix
+String to suffix buttons.
+@end defopt
+
+@defopt widget-push-button-prefix
+String to prefix push buttons.
+@end defopt
+
+@defopt widget-push-button-suffix
+String to suffix push buttons.
+@end defopt
+
+@defopt widget-link-prefix
+String to prefix links.
+@end defopt
+
+@defopt widget-link-suffix
+String to suffix links.
+@end defopt
+
+@defopt widget-choice-toggle
+If non-@code{nil}, toggle when there are just two options.
+
+By default, its value is @code{nil}.
+@end defopt
+
+@defopt widget-documentation-links
+If non-@code{nil}, add hyperlinks to documentation strings.
+@end defopt
+
+@defopt widget-documentation-link-regexp
+A regexp that matches potential links in documentation strings.  The
+link itself should match to the first group.
+@end defopt
+
+@defopt widget-documentation-link-p
+A predicate function to test if a string is useful as a link.  The
+function is called with one argument, a string, and should return
+non-@code{nil} if there should be a link for that string.
+
+By default, the value is @code{intern-soft}.
+@end defopt
+
+@defopt widget-documentation-link-type
+A symbol that represents a widget type to use for links in
+documentation strings.
+
+By default, the value is @code{documentation-link}.
+@end defopt
+
+@defopt widget-menu-max-size
+Maximum size for a popup menu.  By default, its value is 40.
+
+If a function ask you to choose from a menu that is larger than this
+value, it will use the minibuffer.
+@end defopt
+
+@defopt widget-menu-max-shortcuts
+Largest number of items for which it works to choose one with a
+character.
+
+For a larger number, use the minibuffer.
+@end defopt
+
+@defopt widget-menu-minibuffer-flag
+Whether to use the minibuffer to ask for a choice.
+
+If @code{nil}, the default, read a single character.
+@end defopt
+
 @node  Widget Wishlist
 @chapter Wishlist
 @cindex todo
@@ -1808,15 +3173,6 @@ Widget Wishlist
 @item
 Find a way to make glyphs look inactive.
 
-@item
-Add @code{property-list} widget.
-
-@item
-Add @code{association-list} widget.
-
-@item
-Add @code{key-binding} widget.
-
 @item
 Add @code{widget} widget for editing widget specifications.
 
-- 
2.34.1

RE: [External] : Editions to the Widget Manual

[Drew Adams]

Thanks for working on this, Mauro!

I don't work with texi (the original texi text
or patches or patched), but if you can point to
a non-texi version of the patched text (e.g.
plain-text or other) then if/when I get some
time I'll take a look.

Whether that happens or not, thanks again for
doing this.  It will really help, I'm sure.

Re: [External] : Editions to the Widget Manual

[Yuan Fu]

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Thanks for working on this Mauro! The overall structure is clearer, and the additional information is most welcome. I personally think it might be better to move the default widget to under section 8.1 Basic types, in its own subsection, so that it’s easier to look for. In the same vein, adding some cindexes could further help users to find the information they are looking for, when using the manual as a reference.

> On Aug 20, 2023, at 2:59 PM, Drew Adams <drew.adams@oracle.com> wrote:
> 
> Thanks for working on this, Mauro!
> 
> I don't work with texi (the original texi text
> or patches or patched), but if you can point to
> a non-texi version of the patched text (e.g.
> plain-text or other) then if/when I get some
> time I'll take a look.
> 
> Whether that happens or not, thanks again for
> doing this.  It will really help, I'm sure.

Here’s the old and new version in HTML format.

Yuan


[-- Attachment #2: widget.old.html --]
[-- Type: text/html, Size: 201840 bytes --]

[-- Attachment #3: widget.new.html --]
[-- Type: text/html, Size: 300211 bytes --]

Re: [External] : Editions to the Widget Manual

[Mauro Aranda]

On 20/8/23 18:59, Drew Adams wrote:
 > Thanks for working on this, Mauro!
 >
 > I don't work with texi (the original texi text
 > or patches or patched), but if you can point to
 > a non-texi version of the patched text (e.g.
 > plain-text or other) then if/when I get some
 > time I'll take a look.

I see that Yuan posted both the old version and the new one
to the list. Is that OK for you?

If you find the time, I'll really appreciate your comments.

Re: [External] : Editions to the Widget Manual

[Mauro Aranda]

On 20/8/23 20:56, Yuan Fu wrote:

 > Thanks for working on this Mauro! The overall structure is clearer,
 > and the additional information is most welcome. I personally think it
 > might be better to move the default widget to under section 8.1 Basic
 > types, in its own subsection, so that it’s easier to look for.

Thank you for your comments.  I can see why it would be better to move
the default widget description under Basic types.  I'll make that
change.

 > In the same vein, adding some cindexes could further help users to
 > find the information they are looking for, when using the manual as a
 > reference.

Yes, I left the index and references for the final step, so I can
re-read the manual several times to find out what to add.  I'll keep
working on that.

RE: [External] : Editions to the Widget Manual

[Drew Adams]

>  > Thanks for working on this, Mauro!
>  >
>  > I don't work with texi (the original texi text
>  > or patches or patched), but if you can point to
>  > a non-texi version of the patched text (e.g.
>  > plain-text or other) then if/when I get some
>  > time I'll take a look.
> 
> I see that Yuan posted both the old version and the new one
> to the list. Is that OK for you?

Not really.  I'd like to see just the proposed text
and the original, if possible.  Those HTML files are
of the entire manual - 64 pages.

Even a plain-text diff/patch would be more helpful
than texi.  But it's not important - don't go out
of your way just for me.

> If you find the time, I'll really appreciate your comments.

It won't be for a while, I'm afraid.  But hopefully
others will help.  A priori, I wouldn't worry too
much about the English.  If the logic is clear it
should be OK, and others will no doubt correct any
English problems.

Re: [External] : Editions to the Widget Manual

[Corwin Brust]

[-- Attachment #1: Type: text/plain, Size: 267 bytes --]

On Mon, Aug 21, 2023 at 10:42 AM Drew Adams <drew.adams@oracle.com> wrote:
>
> Even a plain-text diff/patch would be more helpful

I've attached plain text versions (makeinfo --plaintext) with and
without the patch as well as a diff -u contrasting them.  hth

[-- Attachment #2: widget.orig_texi.txt --]
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The Emacs Widget Library
1 Introduction
2 User Interface
  2.1 Editable Text Fields
  2.2 Buttons
  2.3 Navigation
3 Programming Example
4 Setting Up the Buffer
5 Basic Types
  5.1 The ‘link’ Widget
  5.2 The ‘url-link’ Widget
  5.3 The ‘info-link’ Widget
  5.4 The ‘push-button’ Widget
  5.5 The ‘editable-field’ Widget
  5.6 The ‘text’ Widget
  5.7 The ‘menu-choice’ Widget
  5.8 The ‘radio-button-choice’ Widget
  5.9 The ‘item’ Widget
  5.10 The ‘choice-item’ Widget
  5.11 The ‘toggle’ Widget
  5.12 The ‘checkbox’ Widget
  5.13 The ‘checklist’ Widget
  5.14 The ‘editable-list’ Widget
  5.15 The ‘group’ Widget
6 Sexp Types
  6.1 The Constant Widgets
  6.2 Generic Sexp Widget
  6.3 Atomic Sexp Widgets
  6.4 Composite Sexp Widgets
7 Properties
8 Defining New Widgets
9 Widget Browser
10 Widget Minor Mode
11 Utilities
12 Wishlist
Appendix A GNU Free Documentation License
Index
The Emacs Widget Library
************************

Copyright © 2000–2023 Free Software Foundation, Inc.

     Permission is granted to copy, distribute and/or modify this
     document under the terms of the GNU Free Documentation License,
     Version 1.3 or any later version published by the Free Software
     Foundation; with no Invariant Sections, with the Front-Cover Texts
     being “A GNU Manual”, and with the Back-Cover Texts as in (a)
     below.  A copy of the license is included in the section entitled
     “GNU Free Documentation License”.

     (a) The FSF’s Back-Cover Text is: “You have the freedom to copy and
     modify this GNU manual.”

1 Introduction
**************

Most graphical user interface toolkits provide a number of standard user
interface controls (sometimes known as “widgets” or “gadgets”).  Emacs
doesn’t really support anything like this, except for an incredibly
powerful text “widget.” On the other hand, Emacs does provide the
necessary primitives to implement many other widgets within a text
buffer.  The ‘widget’ package simplifies this task.

   The basic widgets are:

‘link’
     Areas of text with an associated action.  Intended for hypertext
     links embedded in text.
‘push-button’
     Like link, but intended for stand-alone buttons.
‘editable-field’
     An editable text field.  It can be either variable or fixed length.
‘menu-choice’
     Allows the user to choose one of multiple options from a menu, each
     option is itself a widget.  Only the selected option will be
     visible in the buffer.
‘radio-button-choice’
     Allows the user to choose one of multiple options by activating
     radio buttons.  The options are implemented as widgets.  All
     options will be visible in the buffer.
‘item’
     A simple constant widget intended to be used in the ‘menu-choice’
     and ‘radio-button-choice’ widgets.
‘choice-item’
     A button item only intended for use in choices.  When invoked, the
     user will be asked to select another option from the choice widget.
‘toggle’
     A simple ‘on’/‘off’ switch.
‘checkbox’
     A checkbox (‘[ ]’/‘[X]’).
‘editable-list’
     Create an editable list.  The user can insert or delete items in
     the list.  Each list item is itself a widget.

   Now, of what possible use can support for widgets be in a text
editor?  I’m glad you asked.  The answer is that widgets are useful for
implementing forms.  A “form” in Emacs is a buffer where the user is
supposed to fill out a number of fields, each of which has a specific
meaning.  The user is not supposed to change or delete any of the text
between the fields.  Examples of forms in Emacs are the ‘forms’ package
(of course), the customize buffers, the mail and news compose modes, and
the HTML form support in the ‘w3’ browser.

   The advantages for a programmer of using the ‘widget’ package to
implement forms are:

  1. More complex fields than just editable text are supported.
  2. You can give the users immediate feedback if they enter invalid
     data in a text field, and sometimes prevent entering invalid data.
  3. You can have fixed sized fields, thus allowing multiple fields to
     be lined up in columns.
  4. It is simple to query or set the value of a field.
  5. Editing happens in the buffer, not in the mini-buffer.
  6. Packages using the library get a uniform look, making them easier
     for the user to learn.
  7. As support for embedded graphics improve, the widget library will
     be extended to use the GUI features.  This means that your code
     using the widget library will also use the new graphic features
     automatically.

2 User Interface
****************

A form consists of read only text for documentation and some fields,
where each field contains two parts, a tag and a value.  The tags are
used to identify the fields, so the documentation can refer to the ‘foo
field’, meaning the field tagged with ‘Foo’.  Here is an example form:

     Here is some documentation.

     Name: My Name     *Choose*: This option
     Address:  Some Place
     In some City
     Some country.

     See also _other work_ for more information.

     Numbers: count to three below
     [INS] [DEL] One
     [INS] [DEL] Eh, two?
     [INS] [DEL] Five!
     [INS]

     Select multiple:

     [X] This
     [ ] That
     [X] Thus

     Select one:

     (*) One
     ( ) Another One.
     ( ) A Final One.

     [Apply Form] [Reset Form]

   The top level widgets in this example are tagged ‘Name’, ‘Choose’,
‘Address’, ‘_other work_’, ‘Numbers’, ‘Select multiple’, ‘Select one’,
‘[Apply Form]’, and ‘[Reset Form]’.  There are basically two things the
user can do within a form, namely editing the editable text fields and
activating the buttons.

2.1 Editable Text Fields
========================

In the example, the value for the ‘Name’ is most likely displayed in an
editable text field, and so are values for each of the members of the
‘Numbers’ list.  All the normal Emacs editing operations are available
for editing these fields.  The only restriction is that each change you
make must be contained within a single editable text field.  For
example, capitalizing all text from the middle of one field to the
middle of another field is prohibited.

   Editable text fields are created by the ‘editable-field’ widget.

   *Warning:* In an ‘editable-field’ widget, the editable field must not
be adjacent to another widget—that won’t work.  You must put some text
in between.  Either make this text part of the ‘editable-field’ widget
itself, or insert it with ‘widget-insert’.

   The ‘:format’ keyword is useful for generating the necessary text;
for instance, if you give it a value of ‘"Name: %v "’, the ‘Name: ’ part
will provide the necessary separating text before the field and the
trailing space will provide the separating text after the field.  If you
don’t include the ‘:size’ keyword, the field will extend to the end of
the line, and the terminating newline will provide separation after.

   *Warning:* In an ‘editable-field’ widget, the ‘%v’ escape must be
preceded by some other text in the ‘:format’ string (if specified).

   The editing text fields are highlighted with the ‘widget-field-face’
face, making them easy to find.

 -- Face: widget-field-face
     Face used for other editing fields.

2.2 Buttons
===========

Some portions of the buffer have an associated “action”, which can be
“invoked” by a standard key or mouse command.  These portions are called
“buttons”.  The default commands for activating a button are:

‘<RET>’
      -- Command: widget-button-press POS &optional EVENT
          Invoke the button at POS, defaulting to point.  If point is
          not located on a button, invoke the binding in
          ‘widget-global-map’ (by default the global map).

‘mouse-2’
      -- Command: widget-button-click EVENT
          Invoke the button at the location of the mouse pointer.  If
          the mouse pointer is located in an editable text field, invoke
          the binding in ‘widget-global-map’ (by default the global
          map).

   There are several different kind of buttons, all of which are present
in the example:

_The Option Field Tags_
     When you invoke one of these buttons, you will be asked to choose
     between a number of different options.  This is how you edit an
     option field.  Option fields are created by the ‘menu-choice’
     widget.  In the example, ‘Choose’ is an option field tag.
_The ‘[INS]’ and ‘[DEL]’ buttons_
     Activating these will insert or delete elements from an editable
     list.  The list is created by the ‘editable-list’ widget.
_Embedded Buttons_
     The ‘_other work_’ is an example of an embedded button.  Embedded
     buttons are not associated with any fields, but can serve any
     purpose, such as implementing hypertext references.  They are
     usually created by the ‘link’ widget.
_The ‘[ ]’ and ‘[X]’ buttons_
     Activating one of these will convert it to the other.  This is
     useful for implementing multiple-choice fields.  You can create
     them with the ‘checkbox’ widget.
_The ‘( )’ and ‘(*)’ buttons_
     Only one radio button in a ‘radio-button-choice’ widget can be
     selected at any time.  When you invoke one of the unselected radio
     buttons, it will be selected and the previous selected radio button
     will become unselected.
_The ‘[Apply Form]’ and ‘[Reset Form]’ buttons_
     These are explicit buttons made with the ‘push-button’ widget.  The
     main difference from the ‘link’ widget is that the buttons will be
     displayed as GUI buttons when possible.

   To make them easier to locate, buttons are emphasized in the buffer.

 -- Face: widget-button-face
     Face used for buttons.

 -- User Option: widget-mouse-face
     Face used for highlighting a button when the mouse pointer moves
     across it.

2.3 Navigation
==============

You can use all the normal Emacs commands to move around in a form
buffer, plus you will have these additional commands:

‘<TAB>’
      -- Command: widget-forward &optional count
          Move point COUNT buttons or editing fields forward.
‘M-<TAB>’
‘S-<TAB>’
      -- Command: widget-backward &optional count
          Move point COUNT buttons or editing fields backward.

3 Programming Example
*********************

Here is the code to implement the user interface example (*note User
Interface::).

     (require 'widget)

     (eval-when-compile
       (require 'wid-edit))

     (defvar widget-example-repeat)

     (defun widget-example ()
       "Create the widgets from the Widget manual."
       (interactive)
       (switch-to-buffer "*Widget Example*")
       (kill-all-local-variables)
       (make-local-variable 'widget-example-repeat)
       (let ((inhibit-read-only t))
         (erase-buffer))
       (remove-overlays)
       (widget-insert "Here is some documentation.\n\n")
       (widget-create 'editable-field
                      :size 13
                      :format "Name: %v " ; Text after the field!
                      "My Name")
       (widget-create 'menu-choice
                      :tag "Choose"
                      :value "This"
                      :help-echo "Choose me, please!"
                      :notify (lambda (widget &rest ignore)
                                (message "%s is a good choice!"
                                         (widget-value widget)))
                      '(item :tag "This option" :value "This")
                      '(choice-item "That option")
                      '(editable-field :menu-tag "No option" "Thus option"))
       (widget-create 'editable-field
                      :format "Address: %v"
                      "Some Place\nIn some City\nSome country.")
       (widget-insert "\nSee also ")
       (widget-create 'link
                      :notify (lambda (&rest ignore)
                                (widget-value-set widget-example-repeat
                                                  '("En" "To" "Tre"))
                                (widget-setup))
                      "other work")
       (widget-insert
         " for more information.\n\nNumbers: count to three below\n")
       (setq widget-example-repeat
             (widget-create 'editable-list
                            :entry-format "%i %d %v"
                            :notify
                            (lambda (widget &rest ignore)
                              (let ((old (widget-get widget
                                                     ':example-length))
                                    (new (length (widget-value widget))))
                                (unless (eq old new)
                                  (widget-put widget ':example-length new)
                                  (message "You can count to %d." new))))
                            :value '("One" "Eh, two?" "Five!")
                            '(editable-field :value "three")))
       (widget-insert "\n\nSelect multiple:\n\n")
       (widget-create 'checkbox t)
       (widget-insert " This\n")
       (widget-create 'checkbox nil)
       (widget-insert " That\n")
       (widget-create 'checkbox
                      :notify (lambda (&rest ignore) (message "Tickle"))
                      t)
       (widget-insert " Thus\n\nSelect one:\n\n")
       (widget-create 'radio-button-choice
                      :value "One"
                      :notify (lambda (widget &rest ignore)
                                (message "You selected %s"
                                         (widget-value widget)))
                      '(item "One") '(item "Another One.")
                      '(item "A Final One."))
       (widget-insert "\n")
       (widget-create 'push-button
                      :notify (lambda (&rest ignore)
                                (if (= (length
                                        (widget-value widget-example-repeat))
                                       3)
                                    (message "Congratulation!")
                                  (error "Three was the count!")))
                      "Apply Form")
       (widget-insert " ")
       (widget-create 'push-button
                      :notify (lambda (&rest ignore)
                                (widget-example))
                      "Reset Form")
       (widget-insert "\n")
       (use-local-map widget-keymap)
       (widget-setup))

4 Setting Up the Buffer
***********************

Widgets are created with ‘widget-create’, which returns a “widget”
object.  This object can be queried and manipulated by other widget
functions, until it is deleted with ‘widget-delete’.  After the widgets
have been created, ‘widget-setup’ must be called to enable them.

 -- Function: widget-create type [ keyword argument ]...
     Create and return a widget of type TYPE.  The syntax for the TYPE
     argument is described in *note Basic Types::.

     The keyword arguments can be used to overwrite the keyword
     arguments that are part of TYPE.

 -- Function: widget-delete widget
     Delete WIDGET and remove it from the buffer.

 -- Function: widget-setup
     Set up a buffer to support widgets.

     This should be called after creating all the widgets and before
     allowing the user to edit them.

   If you want to insert text outside the widgets in the form, the
recommended way to do that is with ‘widget-insert’.

 -- Function: widget-insert
     Insert the arguments, either strings or characters, at point.  The
     inserted text will be read-only.

   There is a standard widget keymap which you might find useful.

 -- Const: widget-keymap
     <TAB> and ‘C-<TAB>’ are bound to ‘widget-forward’ and
     ‘widget-backward’, respectively.  <RET> and ‘mouse-2’ are bound to
     ‘widget-button-press’ and ‘widget-button-click’.

 -- Variable: widget-global-map
     Keymap used by ‘widget-button-press’ and ‘widget-button-click’ when
     not on a button.  By default this is ‘global-map’.

5 Basic Types
*************

This is the general syntax of a type specification:

     NAME ::= (NAME [KEYWORD ARGUMENT]... ARGS)
          |   NAME

   Where, NAME is a widget name, KEYWORD is the name of a property,
ARGUMENT is the value of the property, and ARGS are interpreted in a
widget specific way.

   The following keyword arguments apply to all widgets:

‘:value’
     The initial value for widgets of this type.  Typically, a widget
     represents its value in two formats: external and internal.  The
     external format is the value as the rest of Emacs sees it, and the
     internal format is a representation that the widget defines and
     uses in a widget specific way.

     Both formats might be the same for certain widgets and might differ
     for others, and there is no guarantee about which format the value
     stored in the ‘:value’ property has.  However, when creating a
     widget or defining a new one (*note Defining New Widgets::), the
     ‘:value’ should be in the external format.

‘:format’
     This string will be inserted in the buffer when you create a
     widget.  The following ‘%’ escapes are available:

     ‘%[’
     ‘%]’
          The text inside will be marked as a button.

          By default, the text will be shown in ‘widget-button-face’,
          and surrounded by brackets.

           -- User Option: widget-button-prefix
               String to prefix buttons.

           -- User Option: widget-button-suffix
               String to suffix buttons.

     ‘%{’
     ‘%}’
          The text inside will be displayed with the face specified by
          ‘:sample-face’.

     ‘%v’
          This will be replaced with the buffer representation of the
          widget’s value.  What this is depends on the widget type.

          *Warning:* In an ‘editable-field’ widget, the ‘%v’ escape must
          be preceded by some other text in the format string (if
          specified).

     ‘%d’
          Insert the string specified by ‘:doc’ here.

     ‘%h’
          Like ‘%d’, with the following modifications: If the
          documentation string is more than one line, it will add a
          button which will toggle between showing only the first line,
          and showing the full text.  Furthermore, if there is no ‘:doc’
          property in the widget, it will instead examine the
          ‘:documentation-property’ property.  If it is a lambda
          expression, it will be called with the widget’s value as an
          argument, and the result will be used as the documentation
          text.

     ‘%t’
          Insert the string specified by ‘:tag’ here, or the ‘princ’
          representation of the value if there is no tag.

     ‘%%’
          Insert a literal ‘%’.

‘:button-face’
     Face used to highlight text inside %[ %] in the format.

‘:button-prefix’
‘:button-suffix’
     Text around %[ %] in the format.

     These can be
     _nil_
          No text is inserted.

     _a string_
          The string is inserted literally.

     _a symbol_
          The value of the symbol is expanded according to this table.

‘:doc’
     The string inserted by the ‘%d’ escape in the format string.

‘:tag’
     The string inserted by the ‘%t’ escape in the format string.

‘:tag-glyph’
     Name of image to use instead of the string specified by ‘:tag’ on
     Emacsen that supports it.

‘:help-echo’
     Specifies how to display a message whenever you move to the widget
     with either ‘widget-forward’ or ‘widget-backward’ or move the mouse
     over it (using the standard ‘help-echo’ mechanism).  The argument
     is either a string to display, a function of one argument, the
     widget, which should return a string to display, or a form that
     evaluates to such a string.

‘:follow-link’
     Specifies how to interpret a <mouse-1> click on the widget.  *Note
     Defining Clickable Text: (elisp)Clickable Text.

‘:indent’
     An integer indicating the absolute number of spaces to indent
     children of this widget.

‘:offset’
     An integer indicating how many extra spaces to add to the widget’s
     grandchildren compared to this widget.

‘:extra-offset’
     An integer indicating how many extra spaces to add to the widget’s
     children compared to this widget.

‘:notify’
     A function called each time the widget or a nested widget is
     changed.  The function is called with two or three arguments.  The
     first argument is the widget itself, the second argument is the
     widget that was changed, and the third argument is the event
     leading to the change, if any.

‘:menu-tag’
     Tag used in the menu when the widget is used as an option in a
     ‘menu-choice’ widget.

‘:menu-tag-get’
     Function used for finding the tag when the widget is used as an
     option in a ‘menu-choice’ widget.  By default, the tag used will be
     either the ‘:menu-tag’ or ‘:tag’ property if present, or the
     ‘princ’ representation of the ‘:value’ property if not.

‘:match’
     Should be a function called with two arguments, the widget and an
     external value, and should return non-‘nil’ if the widget can
     represent the specified value.

‘:validate’
     A function which takes a widget as an argument, and returns ‘nil’
     if the widget’s current value is valid for the widget.  Otherwise
     it should return the widget containing the invalid data, and set
     that widget’s ‘:error’ property to a string explaining the error.

     The following predefined function can be used:

      -- Function: widget-children-validate widget
          All the ‘:children’ of WIDGET must be valid.

‘:tab-order’
     Specify the order in which widgets are traversed with
     ‘widget-forward’ or ‘widget-backward’.  This is only partially
     implemented.

       a. Widgets with tabbing order ‘-1’ are ignored.

       b. (Unimplemented) When on a widget with tabbing order N, go to
          the next widget in the buffer with tabbing order N+1 or ‘nil’,
          whichever comes first.

       c. When on a widget with no tabbing order specified, go to the
          next widget in the buffer with a positive tabbing order, or
          ‘nil’

‘:parent’
     The parent of a nested widget (e.g., a ‘menu-choice’ item or an
     element of a ‘editable-list’ widget).

‘:sibling-args’
     This keyword is only used for members of a ‘radio-button-choice’ or
     ‘checklist’.  The value should be a list of extra keyword
     arguments, which will be used when creating the ‘radio-button’ or
     ‘checkbox’ associated with this item.

 -- User Option: widget-image-directory
     Directory where Widget should look for images.  Widget will look
     here for a file with the same name as specified for the image, with
     either a ‘.xpm’ (if supported) or ‘.xbm’ extension.

 -- User Option: widget-image-enable
     If non-‘nil’, allow images to appear on displays where they are
     supported.

5.1 The ‘link’ Widget
=====================

Syntax:

     TYPE ::= (link [KEYWORD ARGUMENT]...  [ VALUE ])

   The VALUE, if present, is used to initialize the ‘:value’ property.
The value should be a string, which will be inserted in the buffer.

   By default the link will be shown in brackets.

 -- User Option: widget-link-prefix
     String to prefix links.

 -- User Option: widget-link-suffix
     String to suffix links.

5.2 The ‘url-link’ Widget
=========================

Syntax:

     TYPE ::= (url-link [KEYWORD ARGUMENT]...  URL)

   When this link is invoked, the WWW browser specified by
‘browse-url-browser-function’ will be called with URL.

5.3 The ‘info-link’ Widget
==========================

Syntax:

     TYPE ::= (info-link [KEYWORD ARGUMENT]...  ADDRESS)

   When this link is invoked, the built-in Info reader is started on
ADDRESS.

5.4 The ‘push-button’ Widget
============================

Syntax:

     TYPE ::= (push-button [KEYWORD ARGUMENT]...  [ VALUE ])

   The VALUE, if present, is used to initialize the ‘:value’ property.
The value should be a string, which will be inserted in the buffer.

   By default the tag will be shown in brackets.

 -- User Option: widget-push-button-prefix
     String to prefix push buttons.

 -- User Option: widget-push-button-suffix
     String to suffix push buttons.

5.5 The ‘editable-field’ Widget
===============================

Syntax:

     TYPE ::= (editable-field [KEYWORD ARGUMENT]... [ VALUE ])

   The VALUE, if present, is used to initialize the ‘:value’ property.
The value should be a string, which will be inserted in the field.  This
widget will match all string values.

   The following extra properties are recognized:

‘:size’
     The width of the editable field.
     By default the field will reach to the end of the line.

‘:value-face’
     Face used for highlighting the editable field.  Default is
     ‘widget-field-face’, see *note User Interface::.

‘:secret’
     Character used to display the value.  You can set this to, e.g.,
     ‘?*’ if the field contains a password or other secret information.
     By default, this is ‘nil’, and the value is not secret.

‘:valid-regexp’
     By default the ‘:validate’ function will match the content of the
     field with the value of this attribute.  The default value is ‘""’
     which matches everything.

‘:keymap’
     Keymap used in the editable field.  The default value is
     ‘widget-field-keymap’, which allows you to use all the normal
     editing commands, even if the buffer’s major mode suppresses some
     of them.  Pressing <RET> invokes the function specified by
     ‘:action’.

5.6 The ‘text’ Widget
=====================

This is just like ‘editable-field’, but intended for multiline text
fields.  The default ‘:keymap’ is ‘widget-text-keymap’, which does not
rebind the <RET> key.

5.7 The ‘menu-choice’ Widget
============================

Syntax:

     TYPE ::= (menu-choice [KEYWORD ARGUMENT]... TYPE ... )

   The TYPE argument represents each possible choice.  The widget’s
value will be that of the chosen TYPE argument.  This widget will match
any value matching at least one of the specified TYPE arguments.

‘:void’
     Widget type used as a fallback when the value does not match any of
     the specified TYPE arguments.

‘:case-fold’
     Set this to ‘nil’ if you don’t want to ignore case when prompting
     for a choice through the minibuffer.

‘:children’
     A list whose CAR is the widget representing the currently chosen
     type in the buffer.

‘:choice’
     The current chosen type.

‘:args’
     The list of types.

5.8 The ‘radio-button-choice’ Widget
====================================

Syntax:

     TYPE ::= (radio-button-choice [KEYWORD ARGUMENT]...  TYPE ... )

   The component types specify the choices, with one radio button for
each.  The widget’s value will be that of the chosen TYPE argument.
This widget matches any value that matches at least one of the specified
TYPE arguments.

   The following extra properties are recognized.

‘:entry-format’
     This string will be inserted for each entry in the list.  The
     following ‘%’ escapes are available:
     ‘%v’
          Replace with the buffer representation of the TYPE widget.
     ‘%b’
          Replace with the radio button.
     ‘%%’
          Insert a literal ‘%’.

‘:button-args’
     A list of keywords to pass to the radio buttons.  Useful for
     setting, e.g., the ‘:help-echo’ for each button.

‘:buttons’
     The widgets representing the radio buttons.

‘:children’
     The widgets representing each type.

‘:choice’
     The current chosen type

‘:args’
     The list of types.

   You can add extra radio button items to a ‘radio-button-choice’
widget after it has been created with the function
‘widget-radio-add-item’.

 -- Function: widget-radio-add-item widget type
     Add to ‘radio-button-choice’ widget WIDGET a new radio button item
     of type TYPE.

   Please note that such items added after the ‘radio-button-choice’
widget has been created will *not* be properly destructed when you call
‘widget-delete’.

5.9 The ‘item’ Widget
=====================

Syntax:

     ITEM ::= (item [KEYWORD ARGUMENT]... VALUE)

   The VALUE, if present, is used to initialize the ‘:value’ property.
The value should be a string, which will be inserted in the buffer.
This widget will only match the specified value.

5.10 The ‘choice-item’ Widget
=============================

Syntax:

     ITEM ::= (choice-item [KEYWORD ARGUMENT]... VALUE)

   The VALUE, if present, is used to initialize the ‘:value’ property.
The value should be a string, which will be inserted in the buffer as a
button.  Activating the button of a ‘choice-item’ is equivalent to
activating the parent widget.  This widget will only match the specified
value.

5.11 The ‘toggle’ Widget
========================

Syntax:

     TYPE ::= (toggle [KEYWORD ARGUMENT]...)

   The widget has two possible states, ‘on’ and ‘off’, which correspond
to a ‘t’ or ‘nil’ value, respectively.

   The following extra properties are recognized:

‘:on’
     A string representing the ‘on’ state.  By default the string ‘on’.
‘:off’
     A string representing the ‘off’ state.  By default the string
     ‘off’.
‘:on-glyph’
     Name of a glyph to be used instead of the ‘:on’ text string, on
     emacsen that supports this.
‘:off-glyph’
     Name of a glyph to be used instead of the ‘:off’ text string, on
     emacsen that supports this.

5.12 The ‘checkbox’ Widget
==========================

This widget has two possible states, ‘selected’ and ‘unselected’, which
corresponds to a ‘t’ or ‘nil’ value.

   Syntax:

     TYPE ::= (checkbox [KEYWORD ARGUMENT]...)

5.13 The ‘checklist’ Widget
===========================

Syntax:

     TYPE ::= (checklist [KEYWORD ARGUMENT]...  TYPE ... )

   The TYPE arguments represent each checklist item.  The widget’s value
will be a list containing the values of all checked TYPE arguments.  The
checklist widget will match a list whose elements all match at least one
of the specified TYPE arguments.

   The following extra properties are recognized:

‘:entry-format’
     This string will be inserted for each entry in the list.  The
     following ‘%’ escapes are available:
     ‘%v’
          Replaced with the buffer representation of the TYPE widget.
     ‘%b’
          Replace with the checkbox.
     ‘%%’
          Insert a literal ‘%’.

‘:greedy’
     Usually a checklist will only match if the items are in the exact
     sequence given in the specification.  By setting ‘:greedy’ to
     non-‘nil’, it will allow the items to come in any sequence.
     However, if you extract the value they will be in the sequence
     given in the checklist, i.e., the original sequence is forgotten.

‘:button-args’
     A list of keywords to pass to the checkboxes.  Useful for setting,
     e.g., the ‘:help-echo’ for each checkbox.

‘:buttons’
     The widgets representing the checkboxes.

‘:children’
     The widgets representing each type.

‘:args’
     The list of types.

5.14 The ‘editable-list’ Widget
===============================

Syntax:

     TYPE ::= (editable-list [KEYWORD ARGUMENT]... TYPE)

   The value is a list, where each member represents one widget of type
TYPE.

   The following extra properties are recognized:

‘:entry-format’
     This string will be inserted for each entry in the list.  The
     following ‘%’ escapes are available:
     ‘%v’
          This will be replaced with the buffer representation of the
          TYPE widget.
     ‘%i’
          Insert the [INS] button.
     ‘%d’
          Insert the [DEL] button.
     ‘%%’
          Insert a literal ‘%’.

‘:insert-button-args’
     A list of keyword arguments to pass to the insert buttons.

‘:delete-button-args’
     A list of keyword arguments to pass to the delete buttons.

‘:append-button-args’
     A list of keyword arguments to pass to the trailing insert button.

‘:buttons’
     The widgets representing the insert and delete buttons.

‘:children’
     The widgets representing the elements of the list.

‘:args’
     List whose CAR is the type of the list elements.

5.15 The ‘group’ Widget
=======================

This widget simply group other widgets together.

   Syntax:

     TYPE ::= (group [KEYWORD ARGUMENT]... TYPE...)

   The value is a list, with one member for each TYPE.

6 Sexp Types
************

A number of widgets for editing “s-expressions” (Lisp types), sexp for
short, are also available.  These basically fall in several categories
described in this section.

6.1 The Constant Widgets
========================

The ‘const’ widget can contain any Lisp expression, but the user is
prohibited from editing it, which is mainly useful as a component of one
of the composite widgets.

   The syntax for the ‘const’ widget is:

     TYPE ::= (const [KEYWORD ARGUMENT]...  [ VALUE ])

   The VALUE, if present, is used to initialize the ‘:value’ property
and can be any s-expression.

 -- Widget: const
     This will display any valid s-expression in an immutable part of
     the buffer.

   There are two variations of the ‘const’ widget, namely
‘variable-item’ and ‘function-item’.  These should contain a symbol with
a variable or function binding.  The major difference from the ‘const’
widget is that they will allow the user to see the variable or function
documentation for the symbol.

 -- Widget: variable-item
     An immutable symbol that is bound as a variable.

 -- Widget: function-item
     An immutable symbol that is bound as a function.

6.2 Generic Sexp Widget
=======================

The ‘sexp’ widget can contain any Lisp expression, and allows the user
to edit it inline in the buffer.

   The syntax for the ‘sexp’ widget is:

     TYPE ::= (sexp [KEYWORD ARGUMENT]...  [ VALUE ])

 -- Widget: sexp
     This will allow you to edit any valid s-expression in an editable
     buffer field.

     The ‘sexp’ widget takes the same keyword arguments as the
     ‘editable-field’ widget.  *Note editable-field::.

6.3 Atomic Sexp Widgets
=======================

The atoms are s-expressions that do not consist of other s-expressions.
For example, a string, a file name, or a symbol are atoms, while a list
is a composite type.  You can edit the value of an atom with the
following widgets.

   The syntax for all the atoms are:

     TYPE ::= (CONSTRUCT [KEYWORD ARGUMENT]...  [ VALUE ])

   The VALUE, if present, is used to initialize the ‘:value’ property
and must be an expression of the same type as the widget.  That is, the
string widget can only be initialized with a string.

   All the atom widgets take the same keyword arguments as the
‘editable-field’ widget.  *Note editable-field::.

 -- Widget: string
     Allows you to edit a string in an editable field.

 -- Widget: regexp
     Allows you to edit a regular expression in an editable field.

 -- Widget: character
     Allows you to enter a character in an editable field.

 -- Widget: file
     Allows you to edit a file name in an editable field.

     Keywords:
     ‘:must-match’
          If this is set to non-‘nil’, only existing file names will be
          allowed in the minibuffer.

 -- Widget: directory
     Allows you to edit a directory name in an editable field.  Similar
     to the ‘file’ widget.

 -- Widget: symbol
     Allows you to edit a Lisp symbol in an editable field.

 -- Widget: function
     Allows you to edit a lambda expression, or a function name with
     completion.

 -- Widget: variable
     Allows you to edit a variable name, with completion.

 -- Widget: integer
     Allows you to edit an integer in an editable field.

 -- Widget: number
     Allows you to edit a number in an editable field.

 -- Widget: boolean
     Allows you to edit a boolean.  In Lisp this means a variable which
     is either ‘nil’ meaning false, or non-‘nil’ meaning true.

6.4 Composite Sexp Widgets
==========================

The syntax for the composite widget construct is:

     TYPE ::= (CONSTRUCT [KEYWORD ARGUMENT]...  COMPONENT...)

where each COMPONENT must be a widget type.  Each component widget will
be displayed in the buffer, and will be editable by the user.

 -- Widget: cons
     The value of a ‘cons’ widget must be a cons-cell whose CAR and CDR
     have two specified types.  It uses this syntax:

          TYPE ::= (cons [KEYWORD ARGUMENT]...  CAR-TYPE CDR-TYPE)

 -- Widget: choice
     The value matched by a ‘choice’ widget must have one of a fixed set
     of types.  The widget’s syntax is as follows:

          TYPE ::= (choice [KEYWORD ARGUMENT]...  TYPE ... )

     The value of a ‘choice’ widget can be anything that matches any of
     the TYPES.

 -- Widget: list
     The value of a ‘list’ widget must be a list whose element types
     match the specified component types:

          TYPE ::= (list [KEYWORD ARGUMENT]...  COMPONENT-TYPE...)

     Thus, ‘(list string number)’ matches lists of two elements, the
     first being a string and the second being a number.

 -- Widget: vector
     The ‘vector’ widget is like the ‘list’ widget but matches vectors
     instead of lists.  Thus, ‘(vector string number)’ matches vectors
     of two elements, the first being a string and the second being a
     number.

   The above suffice for specifying fixed size lists and vectors.  To
get variable length lists and vectors, you can use a ‘choice’, ‘set’, or
‘repeat’ widget together with the ‘:inline’ keyword.  If any component
of a composite widget has the ‘:inline’ keyword set, its value must be a
list which will then be spliced into the composite.  For example, to
specify a list whose first element must be a file name, and whose
remaining elements should either be the symbol ‘t’ or two strings (file
names), you can use the following widget specification:

     (list file
           (choice (const t)
                   (list :inline t
                         :value ("foo" "bar")
                         string string)))

   The value of a widget of this type will either have the form ‘(file
t)’ or ‘(file STRING STRING)’.

   This concept of ‘:inline’ may be hard to understand.  It was
certainly hard to implement, so instead of confusing you more by trying
to explain it here, I’ll just suggest you meditate over it for a while.

 -- Widget: set
     Specifies a type whose values are the lists whose elements all
     belong to a given set.  The order of elements of the list is not
     significant.  Here’s the syntax:

          TYPE ::= (set [KEYWORD ARGUMENT]...  PERMITTED-ELEMENT ... )

     Use ‘const’ to specify each permitted element, like this: ‘(set
     (const a) (const b))’.

 -- Widget: repeat
     Specifies a list of any number of elements that fit a certain type.

          TYPE ::= (repeat [KEYWORD ARGUMENT]...  TYPE)

7 Properties
************

You can examine or set the value of a widget by using the widget object
that was returned by ‘widget-create’.

 -- Function: widget-value widget
     Return the current value contained in WIDGET.  It is an error to
     call this function on an uninitialized widget.

 -- Function: widget-value-set widget value
     Set the value contained in WIDGET to VALUE.  It is an error to call
     this function with an invalid VALUE.

   *Important:* You _must_ call ‘widget-setup’ after modifying the value
of a widget before the user is allowed to edit the widget again.  It is
enough to call ‘widget-setup’ once if you modify multiple widgets.  This
is currently only necessary if the widget contains an editing field, but
may be necessary for other widgets in the future.

   If your application needs to associate some information with the
widget objects, for example a reference to the item being edited, it can
be done with ‘widget-put’ and ‘widget-get’.  The property names must
begin with a ‘:’.

 -- Function: widget-put widget property value
     In WIDGET set PROPERTY to VALUE.  PROPERTY should be a symbol,
     while VALUE can be anything.

 -- Function: widget-get widget property
     In WIDGET return the value for PROPERTY.  PROPERTY should be a
     symbol, the value is what was last set by ‘widget-put’ for
     PROPERTY.

 -- Function: widget-member widget property
     Non-‘nil’ if WIDGET has a value (even ‘nil’) for property PROPERTY.

 -- Function: widget-apply widget property &rest args
     Apply the value of PROPERTY to WIDGET, passing ARGS as additional
     arguments to the function.  Return the result of that function
     call.

   Occasionally it can be useful to know which kind of widget you have,
i.e., the name of the widget type you gave when the widget was created.

 -- Function: widget-type widget
     Return the name of WIDGET, a symbol.

   Widgets can be in two states: active, which means they are modifiable
by the user, or inactive, which means they cannot be modified by the
user.  You can query or set the state with the following code:

     ;; Examine if WIDGET is active or not.
     (if (widget-apply WIDGET :active)
         (message "Widget is active.")
       (message "Widget is inactive.")

     ;; Make WIDGET inactive.
     (widget-apply WIDGET :deactivate)

     ;; Make WIDGET active.
     (widget-apply WIDGET :activate)

   A widget is inactive if it, or any of its ancestors (found by
following the ‘:parent’ link), have been deactivated.  To make sure a
widget is really active, you must therefore activate both it and all its
ancestors.

     (while widget
       (widget-apply widget :activate)
       (setq widget (widget-get widget :parent)))

   You can check if a widget has been made inactive by examining the
value of the ‘:inactive’ keyword.  If this is non-‘nil’, the widget
itself has been deactivated.  This is different from using the ‘:active’
keyword, in that the latter tells you if the widget *or* any of its
ancestors have been deactivated.  Do not attempt to set the ‘:inactive’
keyword directly.  Use the ‘:activate’ ‘:deactivate’ keywords instead.

8 Defining New Widgets
**********************

You can define specialized widgets with ‘define-widget’.  It allows you
to create a shorthand for more complex widgets, including specifying
component widgets and new default values for the keyword arguments.

 -- Function: define-widget name class doc &rest args
     Define a new widget type named NAME from ‘class’.

     NAME and class should both be symbols, ‘class’ should be one of the
     existing widget types.

     The third argument DOC is a documentation string for the widget.

     After the new widget has been defined, the following two calls will
     create identical widgets:

        •      (widget-create NAME)

        •      (apply widget-create CLASS ARGS)

   Using ‘define-widget’ just stores the definition of the widget type
in the ‘widget-type’ property of NAME, which is what ‘widget-create’
uses.

   If you only want to specify defaults for keywords with no complex
conversions, you can use ‘identity’ as your conversion function.

   The following additional keyword arguments are useful when defining
new widgets:
‘:convert-widget’
     Function to convert a widget type before creating a widget of that
     type.  It takes a widget type as an argument, and returns the
     converted widget type.  When a widget is created, this function is
     called for the widget type and all the widget’s parent types, most
     derived first.

     The following predefined functions can be used here:

      -- Function: widget-types-convert-widget widget
          Convert ‘:args’ as widget types in WIDGET.

      -- Function: widget-value-convert-widget widget
          Initialize ‘:value’ from ‘:args’ in WIDGET.

‘:copy’
     Function to deep copy a widget type.  It takes a shallow copy of
     the widget type as an argument (made by ‘copy-sequence’), and
     returns a deep copy.  The purpose of this is to avoid having
     different instances of combined widgets share nested attributes.

     The following predefined functions can be used here:

      -- Function: widget-types-copy widget
          Copy ‘:args’ as widget types in WIDGET.

‘:value-to-internal’
     Function to convert the value to the internal format.  The function
     takes two arguments, a widget and an external value, and returns
     the internal value.  The function is called on the present ‘:value’
     when the widget is created, and on any value set later with
     ‘widget-value-set’.

‘:value-to-external’
     Function to convert the value to the external format.  The function
     takes two arguments, a widget and an internal value, and returns
     the external value.

‘:create’
     Function to create a widget from scratch.  The function takes one
     argument, a widget type, and creates a widget of that type, inserts
     it in the buffer, and returns a widget object.

‘:delete’
     Function to delete a widget.  The function takes one argument, a
     widget, and should remove all traces of the widget from the buffer.

     The default value is:

      -- Function: widget-default-delete widget
          Remove WIDGET from the buffer.  Delete all ‘:children’ and
          ‘:buttons’ in WIDGET.

     In most cases you should not change this value, but instead use
     ‘:value-delete’ to make any additional cleanup.

‘:value-create’
     Function to expand the ‘%v’ escape in the format string.  It will
     be called with the widget as its argument and should insert a
     representation of the widget’s value in the buffer.

     Nested widgets should be listed in ‘:children’ or ‘:buttons’ to
     make sure they are automatically deleted.

‘:value-delete’
     Should remove the representation of the widget’s value from the
     buffer.  It will be called with the widget as its argument.  It
     doesn’t have to remove the text, but it should release markers and
     delete nested widgets if these are not listed in ‘:children’ or
     ‘:buttons’.

‘:value-get’
     Function to extract the value of a widget, as it is displayed in
     the buffer.

     The following predefined function can be used here:

      -- Function: widget-value-value-get widget
          Return the ‘:value’ property of WIDGET.

‘:format-handler’
     Function to handle unknown ‘%’ escapes in the format string.  It
     will be called with the widget and the character that follows the
     ‘%’ as arguments.  You can set this to allow your widget to handle
     non-standard escapes.

     You should end up calling ‘widget-default-format-handler’ to handle
     unknown escape sequences, which will handle the ‘%h’ and any future
     escape sequences, as well as give an error for unknown escapes.

‘:action’
     Function to handle user initiated events.  By default, ‘:notify’
     the parent.

     The following predefined function can be used here:

      -- Function: widget-parent-action widget &optional event
          Tell ‘:parent’ of WIDGET to handle the ‘:action’.  Optional
          EVENT is the event that triggered the action.

‘:prompt-value’
     Function to prompt for a value in the minibuffer.  The function
     should take four arguments, WIDGET, PROMPT, VALUE, and UNBOUND and
     should return a value for widget entered by the user.  PROMPT is
     the prompt to use.  VALUE is the default value to use, unless
     UNBOUND is non-‘nil’, in which case there is no default value.  The
     function should read the value using the method most natural for
     this widget, and does not have to check that it matches.

   If you want to define a new widget from scratch, use the ‘default’
widget as its base.

 -- Widget: default
     Widget used as a base for other widgets.

     It provides most of the functionality that is referred to as “by
     default” in this text.

9 Widget Browser
****************

There is a separate package to browse widgets.  This is intended to help
programmers who want to examine the content of a widget.  The browser
shows the value of each keyword, but uses links for certain keywords
such as ‘:parent’, which avoids printing cyclic structures.

 -- Command: widget-browse WIDGET
     Create a widget browser for WIDGET.  When called interactively,
     prompt for WIDGET.

 -- Command: widget-browse-other-window WIDGET
     Create a widget browser for WIDGET and show it in another window.
     When called interactively, prompt for WIDGET.

 -- Command: widget-browse-at POS
     Create a widget browser for the widget at POS.  When called
     interactively, use the position of point.

10 Widget Minor Mode
********************

There is a minor mode for manipulating widgets in major modes that don’t
provide any support for widgets themselves.  This is mostly intended to
be useful for programmers doing experiments.

 -- Command: widget-minor-mode
     Toggle minor mode for traversing widgets.  With arg, turn widget
     mode on if and only if arg is positive.

 -- Variable: widget-minor-mode-keymap
     Keymap used in ‘widget-minor-mode’.

11 Utilities
************

 -- Function: widget-prompt-value widget prompt [ value unbound ]
     Prompt for a value matching WIDGET, using PROMPT.  The current
     value is assumed to be VALUE, unless UNBOUND is non-‘nil’.

 -- Function: widget-get-sibling widget
     Get the item which WIDGET is assumed to toggle.  This is only
     meaningful for radio buttons or checkboxes in a list.

 -- Function: widget-choose title items &optional event
     Prompt the user to choose an item from a list of options.

     TITLE is the name of the list of options.  ITEMS should be a menu,
     with its items in the simple format or in the extended format.
     *Note Defining Menus: (elisp)Defining Menus.  Independently of the
     format, you don’t have to provide a title for the menu, just pass
     the desired title in TITLE.  The optional EVENT is an input event.
     If EVENT is a mouse event and the number of elements in ITEMS is
     less than the user option ‘widget-menu-max-size’, then
     ‘widget-choose’ uses a popup menu to prompt the user.  Otherwise,
     ‘widget-choose’ uses the minibuffer.

     When ITEMS is a keymap menu, the returned value is the symbol in
     the key vector, as in the argument of ‘define-key’ (*note
     (elisp)Changing Key Bindings::).  When ITEMS is a list whose
     selectable items are of the form (NAME .  VALUE) (i.e., the
     simplified format), then the return value is the VALUE of the
     chosen element.

12 Wishlist
***********

   • It should be possible to add or remove items from a list with ‘C-k’
     and ‘C-o’ (suggested by RMS).

   • The ‘[INS]’ and ‘[DEL]’ buttons should be replaced by a single dash
     (‘-’).  The dash should be a button that, when invoked, asks
     whether you want to add or delete an item (RMS wanted to git rid of
     the ugly buttons, the dash is my idea).

   • The ‘menu-choice’ tag should be prettier, something like the
     abbreviated menus in Open Look.

   • Finish ‘:tab-order’.

   • Make indentation work with glyphs and proportional fonts.

   • Add commands to show overview of object and class hierarchies to
     the browser.

   • Find a way to disable mouse highlight for inactive widgets.

   • Find a way to make glyphs look inactive.

   • Add ‘property-list’ widget.

   • Add ‘association-list’ widget.

   • Add ‘key-binding’ widget.

   • Add ‘widget’ widget for editing widget specifications.

   • Find clean way to implement variable length list.  See
     ‘TeX-printer-list’ for an explanation.

   • ‘C-h’ in ‘widget-prompt-value’ should give type specific help.

   • Add a ‘mailto’ widget.

Appendix A GNU Free Documentation License
*****************************************

                     Version 1.3, 3 November 2008

     Copyright © 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
     <https://fsf.org/>

     Everyone is permitted to copy and distribute verbatim copies
     of this license document, but changing it is not allowed.

  0. PREAMBLE

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     This License is a kind of “copyleft”, which means that derivative
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     It complements the GNU General Public License, which is a copyleft
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     We have designed this License in order to use it for manuals for
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Index
*****

This is an alphabetical listing of all concepts, functions, commands,
variables, and widgets described in this manual.

* Menu:

* action keyword:                        Defining New Widgets.
                                                             (line 1333)
* activate a widget:                     Widget Properties.  (line 1181)
* active widget:                         Widget Properties.  (line 1181)
* append-button-args keyword:            editable-list.      (line  919)
* args keyword:                          menu-choice.        (line  731)
* args keyword <1>:                      radio-button-choice.
                                                             (line  771)
* args keyword <2>:                      checklist.          (line  885)
* args keyword <3>:                      editable-list.      (line  928)
* atomic sexp widget:                    atoms.              (line  999)
* basic widgets:                         Introduction.       (line   63)
* boolean:                               atoms.              (line 1052)
* browse-url-browser-function, and url-link widget: url-link.
                                                             (line  629)
* button widgets:                        User Interface.     (line  200)
* button-args keyword:                   radio-button-choice.
                                                             (line  758)
* button-args keyword <1>:               checklist.          (line  875)
* button-face keyword:                   Basic Types.        (line  486)
* button-prefix keyword:                 Basic Types.        (line  489)
* button-suffix keyword:                 Basic Types.        (line  489)
* buttons keyword:                       radio-button-choice.
                                                             (line  762)
* buttons keyword <1>:                   checklist.          (line  879)
* buttons keyword <2>:                   editable-list.      (line  922)
* case-fold keyword:                     menu-choice.        (line  720)
* character:                             atoms.              (line 1021)
* checkbox widget:                       checkbox.           (line  837)
* checklist widget:                      checklist.          (line  847)
* children keyword:                      menu-choice.        (line  724)
* children keyword <1>:                  radio-button-choice.
                                                             (line  765)
* children keyword <2>:                  checklist.          (line  882)
* children keyword <3>:                  editable-list.      (line  925)
* choice:                                composite.          (line 1072)
* choice keyword:                        menu-choice.        (line  728)
* choice keyword <1>:                    radio-button-choice.
                                                             (line  768)
* choice-item widget:                    choice-item.        (line  800)
* composite sexp widgets:                composite.          (line 1059)
* cons:                                  composite.          (line 1066)
* const:                                 constants.          (line  963)
* constant widgets:                      constants.          (line  952)
* convert-widget keyword:                Defining New Widgets.
                                                             (line 1243)
* copy keyword:                          Defining New Widgets.
                                                             (line 1258)
* create keyword:                        Defining New Widgets.
                                                             (line 1281)
* deactivate a widget:                   Widget Properties.  (line 1181)
* default:                               Defining New Widgets.
                                                             (line 1355)
* define-widget:                         Defining New Widgets.
                                                             (line 1219)
* defining new widgets:                  Defining New Widgets.
                                                             (line 1215)
* delete keyword:                        Defining New Widgets.
                                                             (line 1286)
* delete-button-args keyword:            editable-list.      (line  916)
* directory:                             atoms.              (line 1032)
* doc keyword:                           Basic Types.        (line  503)
* editable-field widget:                 editable-field.     (line  663)
* editable-list widget:                  editable-list.      (line  891)
* embedded buttons:                      User Interface.     (line  227)
* entry-format keyword:                  radio-button-choice.
                                                             (line  748)
* entry-format keyword <1>:              checklist.          (line  858)
* entry-format keyword <2>:              editable-list.      (line  900)
* example of using widgets:              Programming Example.
                                                             (line  273)
* external format:                       Basic Types.        (line  422)
* extra-offset keyword:                  Basic Types.        (line  533)
* file:                                  atoms.              (line 1024)
* follow-link keyword:                   Basic Types.        (line  521)
* format keyword:                        Basic Types.        (line  435)
* format-handler keyword:                Defining New Widgets.
                                                             (line 1323)
* function:                              atoms.              (line 1039)
* function-item:                         constants.          (line  976)
* generic sexp widget:                   generic.            (line  982)
* greedy keyword:                        checklist.          (line  868)
* group widget:                          group.              (line  934)
* help-echo keyword:                     Basic Types.        (line  513)
* inactive widget:                       Widget Properties.  (line 1181)
* indent keyword:                        Basic Types.        (line  525)
* info-link widget:                      info-link.          (line  635)
* insert-button-args keyword:            editable-list.      (line  913)
* integer:                               atoms.              (line 1046)
* internal format:                       Basic Types.        (line  422)
* item widget:                           item.               (line  789)
* keymap keyword:                        editable-field.     (line  691)
* keyword arguments:                     Basic Types.        (line  420)
* link widget:                           link.               (line  607)
* list:                                  composite.          (line 1081)
* match keyword:                         Basic Types.        (line  554)
* menu-choice widget:                    menu-choice.        (line  708)
* menu-tag keyword:                      Basic Types.        (line  544)
* menu-tag-get keyword:                  Basic Types.        (line  548)
* mouse-2 (on button widgets):           User Interface.     (line  210)
* must-match keyword:                    atoms.              (line 1028)
* new widgets:                           Defining New Widgets.
                                                             (line 1215)
* notify keyword:                        Basic Types.        (line  537)
* number:                                atoms.              (line 1049)
* off-glyph keyword:                     toggle.             (line  829)
* offset keyword:                        Basic Types.        (line  529)
* on-glyph keyword:                      toggle.             (line  826)
* option field tag:                      User Interface.     (line  220)
* parent keyword:                        Basic Types.        (line  585)
* prompt-value keyword:                  Defining New Widgets.
                                                             (line 1343)
* properties of widgets:                 Widget Properties.  (line 1136)
* push-button widget:                    push-button.        (line  645)
* radio-button-choice widget:            radio-button-choice.
                                                             (line  737)
* regexp:                                atoms.              (line 1018)
* repeat:                                composite.          (line 1128)
* secret keyword:                        editable-field.     (line  681)
* set:                                   composite.          (line 1118)
* sexp:                                  generic.            (line  989)
* sexp types:                            Sexp Types.         (line  945)
* sibling-args keyword:                  Basic Types.        (line  589)
* size keyword:                          editable-field.     (line  673)
* string:                                atoms.              (line 1015)
* symbol:                                atoms.              (line 1036)
* tab-order keyword:                     Basic Types.        (line  570)
* tag keyword:                           Basic Types.        (line  506)
* tag-glyph keyword:                     Basic Types.        (line  509)
* text widget:                           text.               (line  701)
* todo:                                  Widget Wishlist.    (line 1429)
* toggle widget:                         toggle.             (line  813)
* url-link widget:                       url-link.           (line  625)
* utility functions for widgets:         Utilities.          (line 1398)
* valid-regexp keyword:                  editable-field.     (line  686)
* validate keyword:                      Basic Types.        (line  559)
* value keyword:                         Basic Types.        (line  422)
* value-create keyword:                  Defining New Widgets.
                                                             (line 1299)
* value-delete keyword:                  Defining New Widgets.
                                                             (line 1307)
* value-face keyword:                    editable-field.     (line  677)
* value-get keyword:                     Defining New Widgets.
                                                             (line 1314)
* value-to-external keyword:             Defining New Widgets.
                                                             (line 1276)
* value-to-internal keyword:             Defining New Widgets.
                                                             (line 1269)
* variable:                              atoms.              (line 1043)
* variable-item:                         constants.          (line  973)
* vector:                                composite.          (line 1090)
* void keyword:                          menu-choice.        (line  716)
* widget browser:                        Widget Browser.     (line 1364)
* widget buttons:                        User Interface.     (line  200)
* widget library, why use it:            Introduction.       (line  103)
* widget minor mode:                     Widget Minor Mode.  (line 1384)
* widget properties:                     Widget Properties.  (line 1136)
* widget-apply:                          Widget Properties.  (line 1170)
* widget-backward:                       User Interface.     (line  267)
* widget-browse:                         Widget Browser.     (line 1369)
* widget-browse-at:                      Widget Browser.     (line 1377)
* widget-browse-other-window:            Widget Browser.     (line 1373)
* widget-button-click:                   User Interface.     (line  211)
* widget-button-click <1>:               Setting Up the Buffer.
                                                             (line  399)
* widget-button-face:                    User Interface.     (line  249)
* widget-button-prefix:                  Basic Types.        (line  446)
* widget-button-press:                   User Interface.     (line  205)
* widget-button-press <1>:               Setting Up the Buffer.
                                                             (line  399)
* widget-button-suffix:                  Basic Types.        (line  449)
* widget-children-validate:              Basic Types.        (line  567)
* widget-choose:                         Utilities.          (line 1406)
* widget-create:                         Setting Up the Buffer.
                                                             (line  374)
* widget-default-delete:                 Defining New Widgets.
                                                             (line 1292)
* widget-default-format-handler:         Defining New Widgets.
                                                             (line 1329)
* widget-delete:                         Setting Up the Buffer.
                                                             (line  381)
* widget-field-face:                     User Interface.     (line  194)
* widget-field-keymap:                   editable-field.     (line  691)
* widget-forward:                        User Interface.     (line  263)
* widget-get:                            Widget Properties.  (line 1162)
* widget-get-sibling:                    Utilities.          (line 1402)
* widget-global-map:                     Setting Up the Buffer.
                                                             (line  404)
* widget-image-directory:                Basic Types.        (line  595)
* widget-image-enable:                   Basic Types.        (line  600)
* widget-insert:                         Setting Up the Buffer.
                                                             (line  393)
* widget-keymap:                         Setting Up the Buffer.
                                                             (line  399)
* widget-link-prefix:                    link.               (line  616)
* widget-link-suffix:                    link.               (line  619)
* widget-member:                         Widget Properties.  (line 1167)
* widget-minor-mode:                     Widget Minor Mode.  (line 1388)
* widget-minor-mode-keymap:              Widget Minor Mode.  (line 1392)
* widget-mouse-face:                     User Interface.     (line  252)
* widget-parent-action:                  Defining New Widgets.
                                                             (line 1339)
* widget-prompt-value:                   Utilities.          (line 1398)
* widget-push-button-prefix:             push-button.        (line  654)
* widget-push-button-suffix:             push-button.        (line  657)
* widget-put:                            Widget Properties.  (line 1158)
* widget-radio-add-item:                 radio-button-choice.
                                                             (line  778)
* widget-setup:                          Setting Up the Buffer.
                                                             (line  384)
* widget-text-keymap:                    text.               (line  701)
* widget-type:                           Widget Properties.  (line 1178)
* widget-types-convert-widget:           Defining New Widgets.
                                                             (line 1252)
* widget-types-copy:                     Defining New Widgets.
                                                             (line 1266)
* widget-value:                          Widget Properties.  (line 1139)
* widget-value-convert-widget:           Defining New Widgets.
                                                             (line 1255)
* widget-value-set:                      Widget Properties.  (line 1143)
* widget-value-value-get:                Defining New Widgets.
                                                             (line 1320)
* widgets, basic types:                  Introduction.       (line   63)
* widgets, programming example:          Programming Example.
                                                             (line  273)


[-- Attachment #3: widget.txt.patch --]
[-- Type: application/octet-stream, Size: 141634 bytes --]

--- widget.orig_texi.txt	2023-08-21 11:45:19.141060600 -0500
+++ widget.texi.txt	2023-08-21 11:43:40.847561200 -0500
@@ -5,34 +5,46 @@
   2.2 Buttons
   2.3 Navigation
 3 Programming Example
-4 Setting Up the Buffer
-5 Basic Types
-  5.1 The ‘link’ Widget
-  5.2 The ‘url-link’ Widget
-  5.3 The ‘info-link’ Widget
-  5.4 The ‘push-button’ Widget
-  5.5 The ‘editable-field’ Widget
-  5.6 The ‘text’ Widget
-  5.7 The ‘menu-choice’ Widget
-  5.8 The ‘radio-button-choice’ Widget
-  5.9 The ‘item’ Widget
-  5.10 The ‘choice-item’ Widget
-  5.11 The ‘toggle’ Widget
-  5.12 The ‘checkbox’ Widget
-  5.13 The ‘checklist’ Widget
-  5.14 The ‘editable-list’ Widget
-  5.15 The ‘group’ Widget
-6 Sexp Types
-  6.1 The Constant Widgets
-  6.2 Generic Sexp Widget
-  6.3 Atomic Sexp Widgets
-  6.4 Composite Sexp Widgets
-7 Properties
-8 Defining New Widgets
-9 Widget Browser
-10 Widget Minor Mode
-11 Utilities
-12 Wishlist
+4 Widgets Basics
+5 Setting Up the Buffer
+6 Working with Widgets
+7 Widgets and the Buffer
+8 Widget Gallery
+  8.1 Basic Types
+    8.1.1 The ‘item’ Widget
+    8.1.2 The ‘link’ Widget
+    8.1.3 The ‘url-link’ Widget
+    8.1.4 The ‘info-link’ Widget
+    8.1.5 The ‘function-link’ Widget
+    8.1.6 The ‘variable-link’ Widget
+    8.1.7 The ‘face-link’ Widget
+    8.1.8 The ‘file-link’ Widget
+    8.1.9 The ‘emacs-library-link’ Widget
+    8.1.10 The ‘emacs-commentary-link’ Widget
+    8.1.11 The ‘push-button’ Widget
+    8.1.12 The ‘editable-field’ Widget
+    8.1.13 The ‘text’ Widget
+    8.1.14 The ‘menu-choice’ Widget
+    8.1.15 The ‘radio-button-choice’ Widget
+    8.1.16 The ‘choice-item’ Widget
+    8.1.17 The ‘toggle’ Widget
+    8.1.18 The ‘radio-button-toggle’ Widget
+    8.1.19 The ‘checkbox’ Widget
+    8.1.20 The ‘checklist’ Widget
+    8.1.21 The ‘editable-list’ Widget
+    8.1.22 The ‘group’ Widget
+    8.1.23 The ‘documentation-string’ Widget
+  8.2 Sexp Types
+    8.2.1 The Constant Widgets
+    8.2.2 Generic Sexp Widget
+    8.2.3 Atomic Sexp Widgets
+    8.2.4 Composite Sexp Widgets
+9 Defining New Widgets
+10 Inspecting Widgets
+11 Widget Minor Mode
+12 Utilities
+13 Customization
+14 Wishlist
 Appendix A GNU Free Documentation License
 Index
 The Emacs Widget Library
@@ -57,7 +69,7 @@
 Most graphical user interface toolkits provide a number of standard user
 interface controls (sometimes known as “widgets” or “gadgets”).  Emacs
 doesn’t really support anything like this, except for an incredibly
-powerful text “widget.” On the other hand, Emacs does provide the
+powerful text “widget”.  On the other hand, Emacs does provide the
 necessary primitives to implement many other widgets within a text
 buffer.  The ‘widget’ package simplifies this task.
 
@@ -71,13 +83,14 @@
 ‘editable-field’
      An editable text field.  It can be either variable or fixed length.
 ‘menu-choice’
-     Allows the user to choose one of multiple options from a menu, each
-     option is itself a widget.  Only the selected option will be
+     Allows the user to choose one of multiple options from a menu,
+     where each option is itself a widget.  Only the selected option is
      visible in the buffer.
 ‘radio-button-choice’
      Allows the user to choose one of multiple options by activating
      radio buttons.  The options are implemented as widgets.  All
-     options will be visible in the buffer.
+     options are visible in the buffer, with the selected one marked as
+     chosen.
 ‘item’
      A simple constant widget intended to be used in the ‘menu-choice’
      and ‘radio-button-choice’ widgets.
@@ -174,11 +187,6 @@
 
    Editable text fields are created by the ‘editable-field’ widget.
 
-   *Warning:* In an ‘editable-field’ widget, the editable field must not
-be adjacent to another widget—that won’t work.  You must put some text
-in between.  Either make this text part of the ‘editable-field’ widget
-itself, or insert it with ‘widget-insert’.
-
    The ‘:format’ keyword is useful for generating the necessary text;
 for instance, if you give it a value of ‘"Name: %v "’, the ‘Name: ’ part
 will provide the necessary separating text before the field and the
@@ -186,34 +194,18 @@
 don’t include the ‘:size’ keyword, the field will extend to the end of
 the line, and the terminating newline will provide separation after.
 
-   *Warning:* In an ‘editable-field’ widget, the ‘%v’ escape must be
-preceded by some other text in the ‘:format’ string (if specified).
-
    The editing text fields are highlighted with the ‘widget-field-face’
 face, making them easy to find.
 
- -- Face: widget-field-face
-     Face used for other editing fields.
-
 2.2 Buttons
 ===========
 
 Some portions of the buffer have an associated “action”, which can be
 “invoked” by a standard key or mouse command.  These portions are called
-“buttons”.  The default commands for activating a button are:
-
-‘<RET>’
-      -- Command: widget-button-press POS &optional EVENT
-          Invoke the button at POS, defaulting to point.  If point is
-          not located on a button, invoke the binding in
-          ‘widget-global-map’ (by default the global map).
-
-‘mouse-2’
-      -- Command: widget-button-click EVENT
-          Invoke the button at the location of the mouse pointer.  If
-          the mouse pointer is located in an editable text field, invoke
-          the binding in ‘widget-global-map’ (by default the global
-          map).
+“buttons”.  The default commands for activating a button are
+‘widget-button-press’ and ‘widget-button-click’.  The user typically
+interacts with the buttons with a key, like <RET>, or with the mouse
+buttons.
 
    There are several different kind of buttons, all of which are present
 in the example:
@@ -245,28 +237,16 @@
      main difference from the ‘link’ widget is that the buttons will be
      displayed as GUI buttons when possible.
 
-   To make them easier to locate, buttons are emphasized in the buffer.
-
- -- Face: widget-button-face
-     Face used for buttons.
-
- -- User Option: widget-mouse-face
-     Face used for highlighting a button when the mouse pointer moves
-     across it.
+   To make them easier to locate, buttons are emphasized in the buffer
+with a distinctive face, like ‘widget-button-face’ or
+‘widget-mouse-face’.
 
 2.3 Navigation
 ==============
 
 You can use all the normal Emacs commands to move around in a form
-buffer, plus you will have these additional commands:
-
-‘<TAB>’
-      -- Command: widget-forward &optional count
-          Move point COUNT buttons or editing fields forward.
-‘M-<TAB>’
-‘S-<TAB>’
-      -- Command: widget-backward &optional count
-          Move point COUNT buttons or editing fields backward.
+buffer, plus you will have these additional commands to navigate from
+widget to widget: ‘widget-forward’ and ‘widget-backward’.
 
 3 Programming Example
 *********************
@@ -364,68 +344,474 @@
        (use-local-map widget-keymap)
        (widget-setup))
 
-4 Setting Up the Buffer
-***********************
+4 Widgets Basics
+****************
 
-Widgets are created with ‘widget-create’, which returns a “widget”
-object.  This object can be queried and manipulated by other widget
-functions, until it is deleted with ‘widget-delete’.  After the widgets
-have been created, ‘widget-setup’ must be called to enable them.
-
- -- Function: widget-create type [ keyword argument ]...
-     Create and return a widget of type TYPE.  The syntax for the TYPE
-     argument is described in *note Basic Types::.
+The Widget Library deals with widgets objects.  A widget object has
+properties whose value may be anything, be it numbers, strings, symbols,
+functions, etc.  Those properties are referred to as keywords and are
+responsible for the way a widget is represented in a buffer, and control
+the way a user or a program can interact with it.
+
+   The library defines several widget types, and gives you a way to
+define new types as well.  In addition, widgets can derive from other
+types, creating a sort of widget inheritance.  In fact, all widgets
+defined in the Widget Library share a common parent, the “default”
+widget.  In this manual, when we talk about a default behavior, we
+usually mean the behavior as defined by this ‘default’ widget.  *Note
+Widget Gallery::, for a description of each defined widget.
+
+   Defining a new type that derives from a previous one is not mandatory
+to create widgets that work very different from a specified type.  When
+creating a widget, you can override any default property, including
+functions, that control the widget.  That is, you can specialize a
+widget on creation, without having to define it as a new type of widget.
+
+   In addition to the function for defining a widget, this library
+provides functions to create widgets, query and change its properties,
+respond to user events and destroy them.  The following sections
+describe them.
+
+   One important property of a widget is its “value”.  All widgets may
+have a value, which is stored in a so-called “internal format”.  For the
+rest of Emacs, the widget presents its value in a so-called “external
+format”.  Both formats can be equal or different, and each widget is
+responsible for defining how the conversion between each format should
+happen.
+
+   The value property is an important property for almost all widgets,
+and perhaps more important for ‘editable-field’ widgets.  This type of
+widgets allow the user to edit them via the usual editing commands in
+Emacs.  They can also be edited programmatically.  *Important:* You
+_must_ call ‘widget-setup’ after modifying the value of a widget before
+the user is allowed to edit the widget again.  It is enough to call
+‘widget-setup’ once if you modify multiple widgets.  This is currently
+only necessary if the widget contains an editing field, but may be
+necessary for other widgets in the future.
 
-     The keyword arguments can be used to overwrite the keyword
-     arguments that are part of TYPE.
+   If your application needs to associate some information with the
+widget objects, for example a reference to the item being edited, it can
+be done with the ‘widget-put’ and ‘widget-get’ functions.  The property
+names, as shown, are keywords, so they must begin with a ‘:’.
 
- -- Function: widget-delete widget
-     Delete WIDGET and remove it from the buffer.
+5 Setting Up the Buffer
+***********************
+
+To show the widgets in a buffer, you have to create them.  Widget
+creation is actually a two-step process: conversion and creation per se.
+With simple projects, usually the conversion step isn’t really
+important, and you only care about widget creation, so feel free to skip
+the conversion description until you really need to know it.
+
+   Widget conversion is the process that involves taking a widget
+specification and transforming it into a “widget” object, suitable to be
+created, queried and manipulated with other widget functions.  Widget
+creation is the process that takes a widget object and actually inserts
+it in the buffer.
+
+   The simplest function to create a widget is ‘widget-create’, which
+gets a widget specification and returns a widget object.
+
+ -- Function: widget-create type [ keyword argument ]... args
+     Create and return a widget of type TYPE, converting it.
+
+     TYPE is a symbol that specifies a widget type.  KEYWORD may be one
+     of the properties supported by the widget type, and ARGUMENT
+     specify the value for that property.  These keyword arguments can
+     be used to overwrite the keyword arguments that are part of TYPE by
+     default, as well as to provide other properties not present in TYPE
+     by default.  ARGS holds additional information for the creation of
+     TYPE and each widget type is responsible for handling that
+     information in a specific way.
+
+     The syntax for the TYPE argument is described in *note Widget
+     Gallery::, and in more detail in every widget where it’s relevant.
+
+   There are other functions for creating widgets, useful when you work
+with composite widgets.  That is, widgets that are part of other
+widgets.
+
+ -- Function: widget-create-child-and-convert parent type &rest args
+     Create a widget of type TYPE as a child of PARENT.
+
+     Before creating it, converts TYPE using the keyword arguments
+     provided in ARGS.  Adds the ‘:indent’ property, unless it is
+     already present, and sets it to the sum of the values of: ‘:indent’
+     and ‘:offset’ from PARENT and ‘:extra-offset’ from TYPE.
+
+     Returns a widget object, with the property ‘:parent’ set to PARENT.
+
+ -- Function: widget-create-child parent type
+     Create a widget of type TYPE as a child of PARENT.
+
+     This function is like ‘widget-create-child-and-convert’ but it
+     doesn’t convert TYPE, so it expects an already converted widget.
+
+ -- Function: widget-create-child-value parent type value
+     Create a widget of type TYPE as a child of PARENT with value VALUE.
+
+     This function is like ‘widget-create-child’, but it lets you
+     specify a value for the widget.
+
+     Converts VALUE to the internal format, as specified by TYPE, and
+     stores it into the ‘:value’ property of TYPE.  That means, VALUE
+     should be in the external format, as specified by TYPE.
+
+   All these creating functions described here use the function stored
+in the ‘:create’ property.  So, to modify the creation logic for a
+widget, you can provide a different ‘:create’ function.
+
+   When you’re done creating widgets and you’re ready for the user to
+interact with the buffer, use the function ‘widget-setup’.
 
  -- Function: widget-setup
-     Set up a buffer to support widgets.
+     Setup the current buffer, so that editable widgets can be edited.
 
      This should be called after creating all the widgets and before
      allowing the user to edit them.
 
-   If you want to insert text outside the widgets in the form, the
-recommended way to do that is with ‘widget-insert’.
+   As mentioned, all these functions return a widget object.  That
+widget object can be queried and manipulated with widget functions that
+take widgets as arguments, until deleting it with the widgets functions
+available to delete widgets.  Even if you don’t save the returned widget
+object, you still can interact programmatically with the widget.  *Note
+Working with Widgets::.
+
+ -- Function: widget-delete widget
+     Delete the widget WIDGET and remove it from the buffer.
+
+ -- Function: widget-children-value-delete widget
+     Delete all children and buttons in widget WIDGET.
+
+     This function does not delete WIDGET itself, only the widgets
+     stored in the ‘:children’ and ‘:buttons’ properties.  It also sets
+     those properties to ‘nil’.
+
+   As with the creation mechanism, the function stored in ‘:delete’
+controls the deletion mechanism for a widget.
+
+   Additionally, the library provides a way to make a copy of a widget.
+
+ -- Function: widget-copy widget
+     Makes a copy of widget WIDGET and returns it.
+
+     It uses the function stored in the ‘:copy’ property of WIDGET and
+     returns the widget that that function returns.
+
+   As discussed, there is a conversion step when creating a widget.  To
+do the conversion without actually creating the widget, you can use the
+‘widget-convert’ function.
+
+ -- Function: widget-convert type &rest args
+     Convert TYPE to a widget object, using keyword arguments ARGS.
+
+     Returns a widget object, suitable for creation.  It calls the
+     function stored in the ‘:convert-widget’ property, after putting
+     into the ‘:args’ property the arguments that the widget in question
+     needs.  If TYPE has a ‘:value’ property, either originally or after
+     doing the conversion, this function converts the value stored in
+     ‘:value’ to the internal format, and stores it into ‘:value’.
+
+   Apart from only creating widgets in the buffer, It’s useful to have
+plain text.  For inserting text, the recommended way is with the
+‘widget-insert’ function.
+
+ -- Function: widget-insert &rest args
+     Insert ARGS, either strings or characters, at point.
+
+     Uses ‘insert’ to perform the insertion, passing ARGS as argument.
+     *Note (elisp)Insertion::, for more information about ARGS.
+
+     The resulting text will be read-only.
+
+6 Working with Widgets
+**********************
+
+This section covers the more important functions needed to query and
+manipulate widgets in a generic way.  Widgets may have additional
+functions for interacting with them, those are described in the
+description for each widget.  *Note Widget Gallery::.
+
+ -- Function: widgetp widget
+     Non-‘nil’ if WIDGET is a widget.
+
+ -- Function: widget-type widget
+     Return the type of widget WIDGET, a symbol.
+
+     This function is useful to find out which kind of widget WIDGET
+     represents, i.e., the name of the widget type when the widget was
+     created.
+
+ -- Function: widget-member widget property
+     Non-‘nil’ if widget WIDGET has a value (even ‘nil’) for property
+     PROPERTY.
+
+ -- Function: widget-get widget property
+     For widget WIDGET, return the value of the property PROPERTY.
+
+     PROPERTY should be a keyword, and the value is what was last set by
+     ‘widget-put’ for PROPERTY.
+
+ -- Function: widget-put widget property value
+     For widget WIDGET, set the property PROPERTY to VALUE.  PROPERTY
+     should be a keyword, while VALUE can be anything.
+
+ -- Function: widget-at &optional pos
+     Return the widget at position POS, or at point if POS is ‘nil’.
+
+ -- Function: widget-field-at pos
+     Return the widget field at position POS, or ‘nil’ if there is none.
+
+ -- Function: widget-apply widget property &rest args
+     Apply the function stored in PROPERTY to WIDGET, passing ARGS as
+     additional arguments to the function.
+
+     Returns the result of that function call.
+
+ -- Function: widget-value widget
+     Return the current value contained in WIDGET.
+
+     Note that the value returned by this function might differ from
+     what’s stored in the ‘:value’ property of WIDGET.  This is because
+     this function extracts the current value of WIDGET from the buffer,
+     taking editions into account.
+
+     The value returned is in the external format, after getting it with
+     the ‘:value-get’ function.
+
+     It is an error to call this function on an uninitialized widget.
+
+ -- Function: widget-value-set widget value
+     Set the value contained in WIDGET to VALUE.
+
+     Converts VALUE to the internal format, and then sets it by applying
+     the ‘:value-set’ function.
+
+     It is an error to call this function with an invalid VALUE, that
+     is, a value that WIDGET cannot represent.
+
+ -- Function: widget-default-get widget
+     Return the default external value of widget WIDGET.
+
+     The default value is the one stored in ‘:value’ or the result of
+     applying the ‘:default-get’ function to the arguments of WIDGET, as
+     stored in ‘:args’.  A value of ‘nil’ is ignored by default, so in
+     order for a widget to respect ‘nil’ as a value, it has to override
+     the ‘:default-get’ function.
+
+ -- Function: widget-type-default-get widget
+     Convert the ‘:type’ attribute in WIDGET and return its default
+     value.
+
+ -- Function: widget-child-value-get widget
+     Return the value of the first member of ‘:children’ in WIDGET.
+
+ -- Function: widget-child-value-inline widget
+     Return the inline value of the first member of ‘:children’ in
+     WIDGET.
+
+     The inline value is whatever the function stored in ‘:value-inline’
+     returns.
+
+ -- Function: widget-type-value-create widget
+     Create a child widget for WIDGET, of type stored in ‘:type’.
+
+     Creates the child widget taking the value from the ‘:value’
+     property and stores the newly created widget in the ‘:children’
+     property of WIDGET.
+
+     The value stored in ‘:type’ should be an unconverted widget type.
 
- -- Function: widget-insert
-     Insert the arguments, either strings or characters, at point.  The
-     inserted text will be read-only.
+ -- Function: widget-value-convert-widget widget
+     Initializes the ‘:value’ property of WIDGET from ‘:args’.
 
-   There is a standard widget keymap which you might find useful.
+     Sets ‘:args’ to ‘nil’ and returns the modified widget WIDGET.
+
+ -- Function: widget-value-value-get widget
+     Return the value stored in ‘:value’ for widget WIDGET.
+
+     This is different to getting the current value for WIDGET with
+     ‘widget-value’, since that function extracts the value from the
+     buffer.
+
+ -- Function: widget-apply-action widget &optional event
+     Apply the function stored in ‘:action’ to WIDGET, in response to
+     EVENT.
+
+     It is an error to call this function with an inactive widget.
+
+ -- Function: widget-parent-action widget &optional event
+     Tell ‘:parent’ of WIDGET to handle EVENT.
+
+     Optional EVENT is the event that triggered the action.
+
+ -- Function: widget-child-validate widget
+     Check that the first member of ‘:children’ in WIDGET is valid.
+
+     To be valid means that the widget value passes the checks that the
+     function stored in ‘:validate’ makes.
+
+ -- Function: widget-children-validate widget
+     Check that all ‘:children’ in WIDGET are valid.
+
+     Returns ‘nil’ on success, or the first child that isn’t valid.
+
+ -- Function: widget-type-match widget value
+     Return non-‘nil’ if VALUE matches the value for the ‘:type’ widget.
+
+     As with the other type functions, the widget stored in ‘:type’
+     should be an unconverted widget.
+
+ -- Function: widget-types-copy widget
+     Copy the ‘:args’ value in WIDGET and store them in ‘:args’.
+
+     Makes the copies by calling ‘widget-copy’ on each element present
+     in ‘:args’.  Returns the modified widget WIDGET.
+
+ -- Function: widget-types-convert-widget widget
+     Convert the ‘:args’ value in WIDGET and store them in ‘args’.
+
+     Returns the modified widget WIDGET.
+
+7 Widgets and the Buffer
+************************
+
+This chapter describes commands that are specific to buffers that
+contain widgets.
 
  -- Const: widget-keymap
-     <TAB> and ‘C-<TAB>’ are bound to ‘widget-forward’ and
-     ‘widget-backward’, respectively.  <RET> and ‘mouse-2’ are bound to
-     ‘widget-button-press’ and ‘widget-button-click’.
+     Keymap containing useful bindings for buffers containing widgets.
+
+     Binds <TAB> and ‘C-<TAB>’ to ‘widget-forward’ and
+     ‘widget-backward’, respectively.  It also binds <RET> to
+     ‘widget-button-press’ and ‘down-mouse-1’ and ‘down-mouse-2’ to
+     ‘widget-button-click’.
+
+   There’s also a keymap for events that the widget library doesn’t need
+to handle.
 
  -- Variable: widget-global-map
      Keymap used by ‘widget-button-press’ and ‘widget-button-click’ when
      not on a button.  By default this is ‘global-map’.
 
-5 Basic Types
-*************
+   In addition to these two keymaps, each widget might define a keymap
+of its own, active when events happen at that widget.
+
+   The following navigation commands are available:
+
+‘<TAB>’
+      -- Command: widget-forward &optional count
+          Move point COUNT buttons or editing fields forward.
+‘M-<TAB>’
+‘S-<TAB>’
+      -- Command: widget-backward &optional count
+          Move point COUNT buttons or editing fields backward.
+
+   When editing an ‘editable-field’ widget, the following commands are
+available:
+
+‘<C-e>’
+      -- Command: widget-end-of-line
+          Move point to the end of field or end of line, whichever is
+          first.
+
+‘C-k’
+      -- Command: widget-kill-line
+          Kill to end of field or end of line, whichever is first.
+
+‘M-TAB’
+      -- Command: widget-complete
+          Complete the content of the editable field at point.
+
+‘C-m’
+      -- Command: widget-field-activate
+          Invoke the editable field at point.
+
+   The following two are commands that can execute widget actions.
+‘<RET>’
+      -- Command: widget-button-press POS &optional EVENT
+          Invoke the button at POS, defaulting to point.
 
-This is the general syntax of a type specification:
+          Invocation means to run the function stored in the ‘:action’
+          property.
+
+          If point is not located on a button, invoke the binding in
+          ‘widget-global-map’ (by default the global map).
+
+‘mouse-2’
+      -- Command: widget-button-click EVENT
+          Invoke the button at the location of the mouse pointer.
+
+          If the mouse pointer is located in an editable text field,
+          invoke the binding in ‘widget-global-map’ (by default the
+          global map).
+
+          In case the mouse-click is on a widget, calls the function
+          stored in the ‘:mouse-down-action’ property.
+
+8 Widget Gallery
+****************
+
+All widgets can be created from a type specification.  The general
+syntax of a type specification is:
 
      NAME ::= (NAME [KEYWORD ARGUMENT]... ARGS)
           |   NAME
 
-   Where, NAME is a widget name, KEYWORD is the name of a property,
-ARGUMENT is the value of the property, and ARGS are interpreted in a
-widget specific way.
+   Where NAME is a widget name, as defined with ‘define-widget’, KEYWORD
+is the name of a property and ARGUMENT is the value for that property,
+and ARGS are interpreted in a widget specific way.  *Note Defining New
+Widgets::.
+
+   The most basic widget in the Widget Library is the “default” widget.
+It provides the basic behavior for all other widgets, and all its
+properties are present by default in derived widgets.  You’re seldom (if
+ever) going to effectively create a default widget, but here we describe
+its properties and behavior, so that we can describe other widgets only
+by mentioning the properties and behavior those other widgets
+specialize.
+
+ -- Widget: default
+     Widget used as a base for other widgets.
+
+     It provides most of the functionality that is referred to as “by
+     default” in this text.  If you want to define a new widget from
+     scratch, use the ‘default’ widget as its base.
 
    The following keyword arguments apply to all widgets:
 
+‘:create’
+     Function to create a widget from scratch.
+
+     The function takes one argument, a widget type, and creates a
+     widget of that type, inserts it in the buffer, and returns a widget
+     object.
+
+     By default, it inserts the widget at point, using the format
+     provided in the ‘:format’ property.
+
+‘:delete’
+     Function to delete a widget.
+
+     The function should take one argument, a widget, and should remove
+     all traces of the widget from the buffer.
+
+     The default value is:
+
+      -- Function: widget-default-delete widget
+          Remove WIDGET from the buffer.  Delete all ‘:children’ and
+          ‘:buttons’ in WIDGET.
+
+     In most cases you should not change this value, but instead use
+     ‘:value-delete’ to make any additional cleanup.
+
 ‘:value’
-     The initial value for widgets of this type.  Typically, a widget
-     represents its value in two formats: external and internal.  The
-     external format is the value as the rest of Emacs sees it, and the
-     internal format is a representation that the widget defines and
-     uses in a widget specific way.
+     The initial value for widgets of this type.
+
+     Typically, a widget represents its value in two formats: external
+     and internal.  The external format is the value as the rest of
+     Emacs sees it, and the internal format is a representation that the
+     widget defines and uses in a widget specific way.
 
      Both formats might be the same for certain widgets and might differ
      for others, and there is no guarantee about which format the value
@@ -433,6 +819,59 @@
      widget or defining a new one (*note Defining New Widgets::), the
      ‘:value’ should be in the external format.
 
+‘:value-to-internal’
+     Function to convert the value to the internal format.
+
+     The function takes two arguments, a widget and an external value,
+     and returns the internal value.  The function is called on the
+     present ‘:value’ when the widget is created, and on any value set
+     later with ‘widget-value-set’.
+
+‘:value-to-external’
+     Function to convert the value to the external format.
+
+     The function takes two arguments, a widget and an internal value,
+     and returns the value in the external format.
+
+‘:value-create’
+     Function to expand the ‘%v’ escape in the format string.
+
+     It will be called with the widget as its argument and should insert
+     a representation of the widget’s value in the buffer.
+
+‘:value-delete’
+     A function that should remove the representation of the widget’s
+     value from the buffer.
+
+     It will be called with the widget as its argument.  It doesn’t have
+     to remove the text, but it should release markers and delete nested
+     widgets if these are not listed in ‘:children’ or ‘:buttons’.
+
+     By default, it’s a no-op.
+
+‘:value-get’
+     Function to extract the value of a widget, as it is displayed in
+     the buffer.
+
+‘:value-set’
+     Function that takes a widget and a value as arguments, and
+     recreates it.
+
+     The value must already be in the internal format for widget.  By
+     default, it deletes the widget with the ‘:delete’ function and
+     creates it again with the ‘:create’ function.
+
+‘:value-inline’
+     Function that takes a widget and returns its value, inlined.
+
+     Inlined means that if the widget is not inline (i.e., its ‘:inline’
+     property is ‘nil’), the return value is wrapped in a list.
+
+‘:default-get’
+     Function that takes a widget and returns its default value.
+
+     By default, it just returns the value stored in ‘:value’.
+
 ‘:format’
      This string will be inserted in the buffer when you create a
      widget.  The following ‘%’ escapes are available:
@@ -444,12 +883,6 @@
           By default, the text will be shown in ‘widget-button-face’,
           and surrounded by brackets.
 
-           -- User Option: widget-button-prefix
-               String to prefix buttons.
-
-           -- User Option: widget-button-suffix
-               String to suffix buttons.
-
      ‘%{’
      ‘%}’
           The text inside will be displayed with the face specified by
@@ -459,10 +892,6 @@
           This will be replaced with the buffer representation of the
           widget’s value.  What this is depends on the widget type.
 
-          *Warning:* In an ‘editable-field’ widget, the ‘%v’ escape must
-          be preceded by some other text in the format string (if
-          specified).
-
      ‘%d’
           Insert the string specified by ‘:doc’ here.
 
@@ -489,6 +918,11 @@
 
 ‘:button-prefix’
 ‘:button-suffix’
+     Strings used as prefix and suffix for widgets that are buttons.
+
+     By default, the values are ‘widget-button-prefix’ and
+     ‘widget-button-suffix’.
+
      Text around %[ %] in the format.
 
      These can be
@@ -514,10 +948,11 @@
 ‘:help-echo’
      Specifies how to display a message whenever you move to the widget
      with either ‘widget-forward’ or ‘widget-backward’ or move the mouse
-     over it (using the standard ‘help-echo’ mechanism).  The argument
-     is either a string to display, a function of one argument, the
-     widget, which should return a string to display, or a form that
-     evaluates to such a string.
+     over it (using the standard ‘help-echo’ mechanism).
+
+     The value is either a string to display, or a function of one
+     argument, the widget.  If a function, it should return a string to
+     display, or a form that evaluates to such a string.
 
 ‘:follow-link’
      Specifies how to interpret a <mouse-1> click on the widget.  *Note
@@ -525,7 +960,12 @@
 
 ‘:indent’
      An integer indicating the absolute number of spaces to indent
-     children of this widget.
+     children of this widget.  Its value might be ‘nil’ too, which
+     corresponds to a value of 0.
+
+     The default ‘:create’ functions and the functions that create the
+     value per se use this property as a rudimentary layout mechanism
+     for the widgets.
 
 ‘:offset’
      An integer indicating how many extra spaces to add to the widget’s
@@ -535,22 +975,17 @@
      An integer indicating how many extra spaces to add to the widget’s
      children compared to this widget.
 
-‘:notify’
-     A function called each time the widget or a nested widget is
-     changed.  The function is called with two or three arguments.  The
-     first argument is the widget itself, the second argument is the
-     widget that was changed, and the third argument is the event
-     leading to the change, if any.
-
 ‘:menu-tag’
      Tag used in the menu when the widget is used as an option in a
      ‘menu-choice’ widget.
 
 ‘:menu-tag-get’
-     Function used for finding the tag when the widget is used as an
-     option in a ‘menu-choice’ widget.  By default, the tag used will be
-     either the ‘:menu-tag’ or ‘:tag’ property if present, or the
-     ‘princ’ representation of the ‘:value’ property if not.
+     Function that takes a widget and returns the tag when the widget is
+     used as an option in a ‘menu-choice’ widget.
+
+     By default, the tag used will be either the ‘:menu-tag’ or ‘:tag’
+     property if present, or the ‘princ’ representation of the ‘:value’
+     property if not.
 
 ‘:match’
      Should be a function called with two arguments, the widget and an
@@ -559,20 +994,18 @@
 
 ‘:validate’
      A function which takes a widget as an argument, and returns ‘nil’
-     if the widget’s current value is valid for the widget.  Otherwise
-     it should return the widget containing the invalid data, and set
-     that widget’s ‘:error’ property to a string explaining the error.
+     if the widget’s current value is valid for the widget.
 
-     The following predefined function can be used:
+     Otherwise, it should return the widget containing the invalid data,
+     and set that widget’s ‘:error’ property to a string explaining the
+     error.
 
-      -- Function: widget-children-validate widget
-          All the ‘:children’ of WIDGET must be valid.
+     By default, it always returns ‘nil’.
 
 ‘:tab-order’
      Specify the order in which widgets are traversed with
      ‘widget-forward’ or ‘widget-backward’.  This is only partially
      implemented.
-
        a. Widgets with tabbing order ‘-1’ are ignored.
 
        b. (Unimplemented) When on a widget with tabbing order N, go to
@@ -593,134 +1026,508 @@
      arguments, which will be used when creating the ‘radio-button’ or
      ‘checkbox’ associated with this item.
 
- -- User Option: widget-image-directory
-     Directory where Widget should look for images.  Widget will look
-     here for a file with the same name as specified for the image, with
-     either a ‘.xpm’ (if supported) or ‘.xbm’ extension.
+‘:completions-function’
+     Function that takes a widget and returns completion data for that
+     widget, like ‘completion-at-point-functions’ would.  *Note
+     (elisp)Completion::.  It’s used by ‘editable-field’ widgets to
+     provide completions.
+
+     By default, it looks into the property ‘:completions’, which should
+     be a completion table.  If ‘:completions’ is ‘nil’, then it calls
+     the function stored either in the ‘:complete’ or
+     ‘:complete-function’ property.
 
- -- User Option: widget-image-enable
-     If non-‘nil’, allow images to appear on displays where they are
-     supported.
+‘:format-handler’
+     Function to handle unknown ‘%’ escapes in the format string.
+
+     It takes a widget and the character that follows the ‘%’ as
+     arguments.  You can set this to allow your widget to handle
+     non-standard escapes in your own specialized widgets.
+
+     You should end up calling ‘widget-default-format-handler’ to handle
+     unknown escape sequences, which will handle the ‘%h’ and any future
+     escape sequences, as well as give an error for unknown escapes.
+
+‘:button-face-get’
+     Function to return the face used to fontify a widget button.
+
+     Takes a widget and returns an appropriate face for the widget.  By
+     default, it either returns the face stored in the ‘:button-face’
+     property, or calls the ‘:button-face-get’ function from the parent
+     of the widget, if it has one.
+
+‘:mouse-face-get’
+     Function to return the face used to fontify a widget when the mouse
+     pointer hovers over it.
+
+     Takes a widget and returns an appropriate face.  By default, it
+     either returns the face stored in the ‘:mouse-face’ property, or
+     calls the ‘:button-face-get’ function from the parent of the
+     widget, if it has one.
+
+‘:copy’
+     Function to deep copy a widget type.
+
+     It takes a shallow copy of the widget type as an argument (made by
+     ‘copy-sequence’), and returns a deep copy.  The purpose of this is
+     to avoid having different instances of combined widgets share
+     nested attributes.
+
+     Its value by default is ‘identity’.
+
+‘:active’
+     Function that takes a widget and returns ‘t’ if it is active.
+
+     A widget might be effectively always active, if its
+     ‘:always-active’ property is ‘t’.
+
+     Widgets can be in two states: active, which means they are
+     modifiable by the user, or inactive, which means they cannot be
+     modified by the user.  You can query or set the state with the
+     following code:
+
+          ;; Examine if WIDGET is active or not.
+          (if (widget-apply WIDGET :active)
+              (message "Widget is active.")
+            (message "Widget is inactive.")
+
+          ;; Make WIDGET inactive.
+          (widget-apply WIDGET :deactivate)
+
+          ;; Make WIDGET active.
+          (widget-apply WIDGET :activate)
+
+     A widget is inactive if it, or any of its ancestors (found by
+     following the ‘:parent’ link), have been deactivated.  To make sure
+     a widget is really active, you must therefore activate both it and
+     all its ancestors.
+
+          (while widget
+            (widget-apply widget :activate)
+            (setq widget (widget-get widget :parent)))
+
+     You can check if a widget has been made inactive by examining the
+     value of the ‘:inactive’ keyword.  If this is non-‘nil’, the widget
+     itself has been deactivated.  This is different from using the
+     ‘:active’ keyword, in that the latter tells you if the widget *or*
+     any of its ancestors have been deactivated.  Do not attempt to set
+     the ‘:inactive’ keyword directly.  Use the ‘:activate’
+     ‘:deactivate’ functions instead.
+
+‘:activate’
+     Function that takes a widget and makes it active for user
+     modifications.
+
+‘:deactivate’
+     Function that takes a widget and makes it inactive for user
+     modifications.
+
+‘:action’
+     Function that takes a widget and optionally an event, and handles a
+     user initiated event.
+
+     By default, uses the ‘:notify’ function to notify the widget’s
+     parent about the event.
+
+‘:mouse-down-action’
+     Function that takes a widget and optionally an event, and handles a
+     mouse click on the widget.
+
+     By default, it does nothing.
+
+‘:notify’
+     A function called each time the widget or a nested widget is
+     changed.
+
+     The function is called with two or three arguments.  The first
+     argument is the widget itself, the second argument is the widget
+     that was changed, and the third argument is the event leading to
+     the change, if any.
+
+     By default, it passes the notification to the widget’s parent.
+
+‘:prompt-value’
+     Function to prompt for a value in the minibuffer.
+
+     The function should take four arguments, a widget, a prompt (a
+     string), a value and a boolean, and should return a value for the
+     widget, entered by the user.
+
+     The prompt is the prompt to use.  The value is the default value to
+     use, unless the fourtha argument is non-‘nil’, in which case there
+     is no default value.
+
+     The function should read the value using the method most natural
+     for this widget, and does not have to check that it matches.
+
+8.1 Basic Types
+===============
+
+8.1.1 The ‘item’ Widget
+-----------------------
+
+Syntax:
+
+     TYPE ::= (item [KEYWORD ARGUMENT]... VALUE)
 
-5.1 The ‘link’ Widget
-=====================
+   A useful widget that holds a constant value, and can be included in
+other widgets.  Its super is the ‘default’ widget.
+
+   As can be seen in the syntax, the ‘item’ widget is one of the widget
+that handles the ARGS argument to ‘widget-create’ in a specific way.  If
+present, VALUE is used to initialize the ‘:value’ property.  When
+created, it inserts the value as a string in the buffer.
+
+   By default, it has the following properties:
+
+‘:convert-widget’
+     The function that allows it to handle VALUE.
+
+‘:value-create’
+     Prints the representation of ‘:value’ in the buffer.
+
+‘:value-get’
+     Returns the value stored in ‘:value’.
+
+‘:match’
+     A value matches the ‘item’ widget if it’s ‘equal’ to its ‘:value’.
+
+‘:match-inline’
+     Inline values match the ‘item’ widget if ‘:value’ is a sublist of
+     values.
+
+‘:action’
+     The ‘item’ widget notifies itself of an event.
+
+‘:format’
+     By default, the ‘item’ widget inserts its tag in the buffer.
+
+8.1.2 The ‘link’ Widget
+-----------------------
 
 Syntax:
 
      TYPE ::= (link [KEYWORD ARGUMENT]...  [ VALUE ])
 
+   A widget to represent an embedded link.  Its super is the ‘item’
+widget.
+
    The VALUE, if present, is used to initialize the ‘:value’ property.
 The value should be a string, which will be inserted in the buffer.
 
-   By default the link will be shown in brackets.
+   By default, it has the following properties:
 
- -- User Option: widget-link-prefix
-     String to prefix links.
+‘:button-prefix’
+     The value of ‘widget-link-prefix’.
 
- -- User Option: widget-link-suffix
-     String to suffix links.
+‘:button-suffix’
+     The value of ‘widget-link-suffix’.
+
+‘:keymap’
+     A custom keymap for the link widget, so that it can respond to
+     mouse clicks.
+
+‘:follow-link’
+     This property allows the link to respect the value of
+     ‘mouse-1-click-follows-link’.  *Note (elisp)Clickable Text::.
+
+‘:format’
+     Buttonizes the link, to make it clickable.
+
+     If you override this property, you should make sure to provide the
+     ‘%[’ and ‘%]’ escape sequences, so that the link is clickable.
+
+   By default the link will be shown in brackets.
 
-5.2 The ‘url-link’ Widget
-=========================
+8.1.3 The ‘url-link’ Widget
+---------------------------
 
 Syntax:
 
      TYPE ::= (url-link [KEYWORD ARGUMENT]...  URL)
 
-   When this link is invoked, the WWW browser specified by
-‘browse-url-browser-function’ will be called with URL.
+   A widget to represent a link to a web page.  Its super is the ‘link’
+widget.
+
+   It overrides the ‘:action’ property to open up the URL specified.
 
-5.3 The ‘info-link’ Widget
-==========================
+8.1.4 The ‘info-link’ Widget
+----------------------------
 
 Syntax:
 
      TYPE ::= (info-link [KEYWORD ARGUMENT]...  ADDRESS)
 
-   When this link is invoked, the built-in Info reader is started on
-ADDRESS.
+   A widget to represent a link to an info file.  Its super is the
+‘link’ widget.
+
+   It overrides the ‘:action’ property, to a function to start the
+built-in Info reader on ADDRESS, when invoked.
 
-5.4 The ‘push-button’ Widget
-============================
+8.1.5 The ‘function-link’ Widget
+--------------------------------
+
+Syntax:
+
+     TYPE ::= (function-link [KEYWORD ARGUMENT]...  FUNCTION)
+
+   A widget to represent a link to an Emacs function.  Its super is the
+‘link’ widget.
+
+   It overrides the ‘:action’ property, to a function to describe
+FUNCTION.
+
+8.1.6 The ‘variable-link’ Widget
+--------------------------------
+
+Syntax:
+
+     TYPE ::= (variable-link [KEYWORD ARGUMENT]...  VAR)
+
+   A widget to represent a link to an Emacs variable.  Its super is the
+‘link’ widget.
+
+   It overrides the ‘:action’ property, to a function to describe VAR.
+
+8.1.7 The ‘face-link’ Widget
+----------------------------
+
+Syntax:
+
+     TYPE ::= (face-link [KEYWORD ARGUMENT]...  FACE)
+
+   A widget to represent a link to an Emacs face.  Its super is the
+‘link’ widget.
+
+   It overrides the ‘:action’ property, to a function to describe FACE.
+
+8.1.8 The ‘file-link’ Widget
+----------------------------
+
+Syntax:
+
+     TYPE ::= (file-link [KEYWORD ARGUMENT]...  FILE)
+
+   A widget to represent a link to a file.  Its super is the ‘link’
+widget.
+
+   It overrides the ‘:action’ property, to a function to find the file
+FILE.
+
+8.1.9 The ‘emacs-library-link’ Widget
+-------------------------------------
+
+Syntax:
+
+     TYPE ::= (emacs-library-link [KEYWORD ARGUMENT]...  FILE)
+
+   A widget to represent a link to an Emacs Lisp file.  Its super is the
+‘link’ widget.
+
+   It overrides the ‘:action’ property, to a function to find the file
+FILE.
+
+8.1.10 The ‘emacs-commentary-link’ Widget
+-----------------------------------------
+
+Syntax:
+
+     TYPE ::= (emacs-commentary-link [KEYWORD ARGUMENT]...  FILE)
+
+   A widget to represent a link to the Comment section of an Emacs Lisp
+file.  Its super is the ‘link’ widget.
+
+   It overrides the ‘:action’ property, to a function to find the file
+FILE and put point in the Comment section.
+
+8.1.11 The ‘push-button’ Widget
+-------------------------------
 
 Syntax:
 
      TYPE ::= (push-button [KEYWORD ARGUMENT]...  [ VALUE ])
 
+   A widget that acts as a pushable button.  Its super is the ‘item’
+widget.
+
    The VALUE, if present, is used to initialize the ‘:value’ property.
 The value should be a string, which will be inserted in the buffer.
 
-   By default the tag will be shown in brackets.
+   By default, it has the following properties:
+‘:button-prefix’
+     The empty string.
 
- -- User Option: widget-push-button-prefix
-     String to prefix push buttons.
+‘:button-suffix’
+     The empty string.
 
- -- User Option: widget-push-button-suffix
-     String to suffix push buttons.
+‘:value-create’
+     Inserts a representation of the “on” and “off” states for the push
+     button.
+
+     The representation might be an image, stored in the ‘:tag-glyph’
+     property, or text.  If it is text, it might be the value of the
+     ‘:tag’ property, or the ‘:value’ of the widget, surrounded with
+     ‘widget-push-button-prefix’ and ‘widget-push-button-suffix’.  *Note
+     Customization::.
 
-5.5 The ‘editable-field’ Widget
-===============================
+‘:format’
+     Buttonizes the widget, to make it clickable.
+
+8.1.12 The ‘editable-field’ Widget
+----------------------------------
 
 Syntax:
 
      TYPE ::= (editable-field [KEYWORD ARGUMENT]... [ VALUE ])
 
+   A widget that can be edited by the user.  Its super is the ‘default’
+widget.
+
    The VALUE, if present, is used to initialize the ‘:value’ property.
-The value should be a string, which will be inserted in the field.  This
-widget will match all string values.
+The value should be a string, which will be inserted in the field.  If
+not present, ‘:value’ is the empty string.
 
-   The following extra properties are recognized:
+   *Warning:* In an ‘editable-field’ widget, the editable field must not
+be adjacent to another widget—that won’t work.  You must put some text
+in between.  Either make this text part of the ‘editable-field’ widget
+itself, or insert it with ‘widget-insert’.
+
+   This widget either overrides or adds the following properties:
+
+‘:convert-widget’
+     Just like the ‘item’ widget, this function allows it to initialize
+     ‘:value’ from VALUE.
+
+‘:keymap’
+     Keymap used in the editable field.
+
+     The default value is ‘widget-field-keymap’, which allows the user
+     to use all the normal editing commands, even if the buffer’s major
+     mode suppresses some of them.  Pressing <RET> invokes the function
+     specified by ‘:action’.
+
+‘:format’
+     By default, it specifies to insert only the widget’s value.
+
+     *Warning:* In an ‘editable-field’ widget, the ‘%v’ escape must be
+     preceded by some other text in the ‘:format’ string (if specified).
 
 ‘:size’
      The width of the editable field.
+
      By default the field will reach to the end of the line.
 
 ‘:value-face’
-     Face used for highlighting the editable field.  Default is
-     ‘widget-field-face’, see *note User Interface::.
+     Face used for highlighting the editable field.
+
+     Default is ‘widget-field-face’, *note User Interface::.
 
 ‘:secret’
-     Character used to display the value.  You can set this to, e.g.,
-     ‘?*’ if the field contains a password or other secret information.
-     By default, this is ‘nil’, and the value is not secret.
+     Character used to display the value.
+
+     You can set this to, e.g., ‘?*’ if the field contains a password or
+     other secret information.  By default, this is ‘nil’, and the value
+     is not secret.
 
 ‘:valid-regexp’
      By default the ‘:validate’ function will match the content of the
-     field with the value of this attribute.  The default value is ‘""’
-     which matches everything.
+     field with the value of this attribute.
+
+     The default value is ‘""’ which matches everything.
+
+‘:validate’
+     Returns ‘nil’ if the current value of the widget matches the
+     ‘:valid-regexp’ value.
+
+‘:prompt-internal’
+     A function to read a value for widget, used by the ‘:prompt-value’
+     function.
+
+‘:prompt-history’
+     A variable that holds the history of field minibuffer edits.
+
+‘:prompt-value’
+     A function that uses the ‘:prompt-internal’ function and the
+     ‘:prompt-history’ value to prompt for a string, and retun the user
+     response in the external format.
+
+‘:action’
+     When invoked, moves point to the next field.
+
+‘:value-create’
+     Function that takes care of creating the widget, respecting its
+     ‘:size’ and ‘:value’.
+
+‘:value-set’
+     Function to use to modify programatically the current value of the
+     widget.
+
+‘:value-delete’
+     Function that removes the widget so it cannot be edited anymore.
+
+‘:value-get’
+     Function to return the current text in the widget.
+
+     It takes an optional argument, NO-TRUNCATE.  If NO-TRUNCATE is nil,
+     truncates trailing spaces.
+
+‘:match’
+     Function that makes the widget match any string value.
+
+8.1.13 The ‘text’ Widget
+------------------------
+
+Syntax:
+
+     TYPE ::= (text [KEYWORD ARGUMENT]... [ VALUE ])
+
+   A widget just like the ‘editable-field’ widget, but intended for
+multiline text fields.  Its super is the ‘editable-field’ widget.
+
+   It overrides the following properties:
+
+‘:format’
+     By default, prints a tag and the value.
 
 ‘:keymap’
-     Keymap used in the editable field.  The default value is
-     ‘widget-field-keymap’, which allows you to use all the normal
-     editing commands, even if the buffer’s major mode suppresses some
-     of them.  Pressing <RET> invokes the function specified by
-     ‘:action’.
-
-5.6 The ‘text’ Widget
-=====================
-
-This is just like ‘editable-field’, but intended for multiline text
-fields.  The default ‘:keymap’ is ‘widget-text-keymap’, which does not
-rebind the <RET> key.
+     The default is ‘widget-text-keymap’, which does not rebind the
+     <RET> key.
 
-5.7 The ‘menu-choice’ Widget
-============================
+8.1.14 The ‘menu-choice’ Widget
+-------------------------------
 
 Syntax:
 
      TYPE ::= (menu-choice [KEYWORD ARGUMENT]... TYPE ... )
 
+   A widget to represent a menu of options.  Its super is the ‘default’
+widget.
+
    The TYPE argument represents each possible choice.  The widget’s
-value will be that of the chosen TYPE argument.  This widget will match
-any value matching at least one of the specified TYPE arguments.
+value will be that of the chosen TYPE argument.
+
+   It either overrides or adds the following properties:
+
+‘:convert-widget’
+     A function that takes care of converting each possible choice.
+
+‘:copy’
+     A function to copy each possible choice.
+
+‘:format’
+     By default, buttonize the tag and show the value.
 
 ‘:void’
      Widget type used as a fallback when the value does not match any of
      the specified TYPE arguments.
 
+     By default this is an ‘item’ widget.
+
 ‘:case-fold’
-     Set this to ‘nil’ if you don’t want to ignore case when prompting
-     for a choice through the minibuffer.
+     If ‘nil’ don’t ignore case when prompting for a choice through the
+     minibuffer.
+
+     By default, its value is ‘t’.
 
 ‘:children’
      A list whose CAR is the widget representing the currently chosen
@@ -732,19 +1539,77 @@
 ‘:args’
      The list of types.
 
-5.8 The ‘radio-button-choice’ Widget
-====================================
+‘:value-create’
+     The function that inserts the current value for the widget.
+
+     It inserts the first choice that matches, as with the ‘:match’
+     function, the value of the widget.
+
+‘:value-get’
+     Returns the value of the first child for the widget (see the
+     description for ‘:children’ above).
+
+‘:value-inline’
+     Returns the inline value of the first child for the widget.
+
+‘:default-get’
+     The default value for this widget is the default value for the
+     first choice, in case ‘:value’ is missing.
+
+     This means that if you want a specific default value for the
+     ‘menu-choice’ widget, you should either pass a ‘:value’ property
+     when creating it, or arrange the choices so that the first one can
+     hold your desired default value.
+
+‘:mouse-down-action’
+     A function that takes care of showing a menu, if possible and
+     desired.
+
+‘:action’
+     A function that takes care of getting a new choice for the widget.
+
+     Depending on the number of choices available, it may show a menu or
+     just toggle the choices, or even do nothing at all.
+
+     After getting the choice, it recreates the widget and notifies it.
+
+‘:validate’
+     Returns ‘nil’ if the widget’s value is a valid choice.
+
+‘:match’
+     This widget will match any value matching at least one of the
+     specified TYPE arguments.
+
+‘:match-inline’
+     A function that returns non-‘nil’ if the values match the widget,
+     taking into account the ‘:inline’ property.
+
+8.1.15 The ‘radio-button-choice’ Widget
+---------------------------------------
 
 Syntax:
 
      TYPE ::= (radio-button-choice [KEYWORD ARGUMENT]...  TYPE ... )
 
-   The component types specify the choices, with one radio button for
+   A widget to represent a choice from multiple options.  Its super is
+the ‘default’ widget.
+
+   The component TYPES specify the choices, with one radio button for
 each.  The widget’s value will be that of the chosen TYPE argument.
-This widget matches any value that matches at least one of the specified
-TYPE arguments.
 
-   The following extra properties are recognized.
+   It overrides the following properties:
+
+‘:convert-widget’
+     As other composite widgets, a function that takes care of
+     converting each available choice.
+
+‘:copy’
+     A function to copy each available choice.
+
+‘:action’
+     A function that checks if any radio button was pressed and
+     activates the pressed one, possibly deactivating an old one.  Then,
+     it notifies itself.
 
 ‘:entry-format’
      This string will be inserted for each entry in the list.  The
@@ -756,6 +1621,9 @@
      ‘%%’
           Insert a literal ‘%’.
 
+‘:format’
+     By default, it inserts its value.
+
 ‘:button-args’
      A list of keywords to pass to the radio buttons.  Useful for
      setting, e.g., the ‘:help-echo’ for each button.
@@ -767,11 +1635,37 @@
      The widgets representing each type.
 
 ‘:choice’
-     The current chosen type
+     The current chosen type.
 
 ‘:args’
      The list of types.
 
+‘:value-create’
+     A function to insert all available choices.
+
+‘:value-get’
+     Returns the value for the chosen widget.
+
+‘:value-set’
+     A function to set the value to one of its available options.
+
+‘:value-inline’
+     A function that returns the inline value of the child widget.
+
+‘:offset’
+     By default, this widget has an offset of 4.
+
+‘:validate’
+     The widget validates if the current value is valid for one of its
+     children.
+
+‘:match’
+     This widget matches any value that matches at least one of the
+     specified TYPE arguments.
+
+‘:match-inline’
+     Like the ‘:match’ function, but taking into account inline values.
+
    You can add extra radio button items to a ‘radio-button-choice’
 widget after it has been created with the function
 ‘widget-radio-add-item’.
@@ -784,77 +1678,172 @@
 widget has been created will *not* be properly destructed when you call
 ‘widget-delete’.
 
-5.9 The ‘item’ Widget
-=====================
+8.1.16 The ‘choice-item’ Widget
+-------------------------------
 
 Syntax:
 
-     ITEM ::= (item [KEYWORD ARGUMENT]... VALUE)
+     ITEM ::= (choice-item [KEYWORD ARGUMENT]... VALUE)
 
-   The VALUE, if present, is used to initialize the ‘:value’ property.
-The value should be a string, which will be inserted in the buffer.
-This widget will only match the specified value.
+   A widget to represent a choice in a ‘menu-choice’ widget.  Its super
+is the ‘item’ widget.
 
-5.10 The ‘choice-item’ Widget
-=============================
+   The VALUE, if present, is used to initialize the ‘:value’ property.
 
-Syntax:
+   It overrides the following properties:
 
-     ITEM ::= (choice-item [KEYWORD ARGUMENT]... VALUE)
+‘:action’
+     Activating the button of a ‘choice-item’ is equivalent to
+     activating the parent widget.
 
-   The VALUE, if present, is used to initialize the ‘:value’ property.
-The value should be a string, which will be inserted in the buffer as a
-button.  Activating the button of a ‘choice-item’ is equivalent to
-activating the parent widget.  This widget will only match the specified
-value.
+‘:format’
+     By default, it buttonizes the tag (i.e., its value) and adds a
+     newline character at the end of the widget.
 
-5.11 The ‘toggle’ Widget
-========================
+8.1.17 The ‘toggle’ Widget
+--------------------------
 
 Syntax:
 
      TYPE ::= (toggle [KEYWORD ARGUMENT]...)
 
+   A widget that can toggle between two states.  Its super is the ‘item’
+widget.
+
    The widget has two possible states, ‘on’ and ‘off’, which correspond
 to a ‘t’ or ‘nil’ value, respectively.
 
-   The following extra properties are recognized:
+   It either overrides or adds the following properties:
+
+‘:format’
+     By default, it buttonizes the value and adds a newline at the end
+     of the widget.
 
 ‘:on’
      A string representing the ‘on’ state.  By default the string ‘on’.
+
 ‘:off’
      A string representing the ‘off’ state.  By default the string
      ‘off’.
+
 ‘:on-glyph’
      Name of a glyph to be used instead of the ‘:on’ text string, on
      emacsen that supports this.
+
 ‘:off-glyph’
      Name of a glyph to be used instead of the ‘:off’ text string, on
      emacsen that supports this.
 
-5.12 The ‘checkbox’ Widget
-==========================
+‘:value-create’
+     A function for creating the widget’s value, according to its ‘:on’
+     or ‘:off’ state.
+
+‘:action’
+     Function to toggle the state of the widget.  After toggling, it
+     notifies itself.
+
+‘:match’
+     This widget matches anything.
+
+8.1.18 The ‘radio-button-toggle’ Widget
+---------------------------------------
+
+Syntax:
+
+     TYPE ::= (radio-button-toggle [KEYWORD ARGUMENT]...)
+
+   A toggle to use in the ‘radio’ widget.
+
+   It overrides the following properties:
+
+‘:button-prefix’
+     The empty string.
+
+‘:button-suffix’
+     The empty string.
+
+‘:on’
+     The string “(*)”, to represent the ‘on’ state.
+
+‘:off’
+     The string “( )”, to represent the ‘off’ state.
+
+‘:on-glyph’
+     The name of an image to represent the ‘on’ state.
+
+‘:off-glpyh’
+     The name of an image to represent the ‘off’ state.
+
+‘:format’
+     By default, it buttonizes its value.
+
+‘:notify’
+     A function to notify its parent.
 
-This widget has two possible states, ‘selected’ and ‘unselected’, which
-corresponds to a ‘t’ or ‘nil’ value.
+8.1.19 The ‘checkbox’ Widget
+----------------------------
 
-   Syntax:
+Syntax:
 
      TYPE ::= (checkbox [KEYWORD ARGUMENT]...)
 
-5.13 The ‘checklist’ Widget
-===========================
+   A widget to represent a toggle widget, with a checkbox.  Its super is
+the ‘toggle’ widget.
+
+   This widget has two possible states, ‘selected’ and ‘unselected’,
+which corresponds to a ‘t’ or ‘nil’ value, respectively.
+
+   It either overrides or adds the following properties:
+
+‘:button-prefix’
+     The empty string.
+
+‘:button-suffix’
+     The empty string.
+
+‘:format’
+     By default, buttonizes the value.
+
+‘:on’
+     By default, the string “[X]”.
+
+‘:off’
+     By default, the string “[ ]”.
+
+‘:on-glyph’
+     The name of the image to use when the state is ‘on’.
+
+‘:off-glyph’
+     The name of the image to use when the state is ‘off’.
+
+‘:action’
+     A function that toggles the checkbox, notifies the parents and in
+     the ‘on’ state, activates its siblings.
+
+8.1.20 The ‘checklist’ Widget
+-----------------------------
 
 Syntax:
 
      TYPE ::= (checklist [KEYWORD ARGUMENT]...  TYPE ... )
 
+   A widget to represent a multiplice choice.  Its super is the
+‘default’ widget.
+
    The TYPE arguments represent each checklist item.  The widget’s value
-will be a list containing the values of all checked TYPE arguments.  The
-checklist widget will match a list whose elements all match at least one
-of the specified TYPE arguments.
+will be a list containing the values of all checked TYPE arguments.
 
-   The following extra properties are recognized:
+   It either overrides or adds the following properties:
+
+‘:convert-widget’
+     As other composite widgets, a function that takes care of
+     converting each checklist item.
+
+‘:copy’
+     A function to copy each checklist item.
+
+‘:format’
+     By default, it inserts its value.
 
 ‘:entry-format’
      This string will be inserted for each entry in the list.  The
@@ -866,13 +1855,6 @@
      ‘%%’
           Insert a literal ‘%’.
 
-‘:greedy’
-     Usually a checklist will only match if the items are in the exact
-     sequence given in the specification.  By setting ‘:greedy’ to
-     non-‘nil’, it will allow the items to come in any sequence.
-     However, if you extract the value they will be in the sequence
-     given in the checklist, i.e., the original sequence is forgotten.
-
 ‘:button-args’
      A list of keywords to pass to the checkboxes.  Useful for setting,
      e.g., the ‘:help-echo’ for each checkbox.
@@ -886,17 +1868,48 @@
 ‘:args’
      The list of types.
 
-5.14 The ‘editable-list’ Widget
-===============================
+‘:value-create’
+     The function that takes care of inserting all values.
+
+‘:value-get’
+     A function that returns all values of selected items.
+
+‘:validate’
+     A function that ensures all selected children are valid.
+
+‘:match’
+     The checklist widget will match a list whose elements all match at
+     least one of the specified TYPE arguments.
+
+‘:match-inline’
+     Like the ‘:match’ function, but taking into account the ‘:inline’
+     property.
+
+‘:greedy’
+     Usually a checklist will only match if the items are in the exact
+     sequence given in the specification.  By setting ‘:greedy’ to
+     non-‘nil’, it will allow the items to come in any sequence.
+     However, if you extract the value they will be in the sequence
+     given in the checklist, i.e., the original sequence is forgotten.
+
+8.1.21 The ‘editable-list’ Widget
+---------------------------------
 
 Syntax:
 
      TYPE ::= (editable-list [KEYWORD ARGUMENT]... TYPE)
 
-   The value is a list, where each member represents one widget of type
-TYPE.
+   A widget that can hold a variable list of widgets of the same type,
+represented by TYPE.  Its super is the ‘default’ widget.
 
-   The following extra properties are recognized:
+   It either overrides or adds the following properties:
+
+‘:convert-widget’
+     As other composite widgets, a function that takes care of
+     converting each type in TYPE.
+
+‘:copy’
+     A function to copy the types given in TYPE.
 
 ‘:entry-format’
      This string will be inserted for each entry in the list.  The
@@ -905,9 +1918,9 @@
           This will be replaced with the buffer representation of the
           TYPE widget.
      ‘%i’
-          Insert the [INS] button.
+          Insert the [INS] button, a widget of type ‘insert-button’.
      ‘%d’
-          Insert the [DEL] button.
+          Insert the [DEL] button, a widget of type ‘delete-button’.
      ‘%%’
           Insert a literal ‘%’.
 
@@ -923,32 +1936,138 @@
 ‘:buttons’
      The widgets representing the insert and delete buttons.
 
+‘:format’
+     By default, insert its value and at the and adds an insert button.
+
+     This is useful so that new elements can be added to the list upon
+     user request.
+
+‘:format-handler’
+     A function that recognize the escape for inserting an insert
+     button.
+
+‘:offset’
+     By default, this widget has an offset of 12.
+
 ‘:children’
      The widgets representing the elements of the list.
 
 ‘:args’
      List whose CAR is the type of the list elements.
 
-5.15 The ‘group’ Widget
-=======================
+‘:insert-before’
+     Function to insert a new widget as a child of the ‘editable-list’
+     widget.
+
+     This function inserts a recently deleted child, if there is one.
+     That is useful, so that the user can move elements in a list
+     easily.  If there is not a recently deleted child, it inserts a
+     child with its default value.
+
+‘:delete-at’
+     Function to delete a child from the widget, and store it into the
+     ‘:last-deleted’ list, so that it can be reinserted when the
+     ‘:insert-before’ function executes.
+
+‘:value-create’
+     The function that takes care of inserting all values.
+
+‘:value-get’
+     Function that returns a list with the value of the child widgets.
+
+‘:validate’
+     This widget validates if all children validate.
 
-This widget simply group other widgets together.
+‘:match’
+     To match, the value must be a list and all the list members must
+     match the specified TYPE.
+
+‘:match-inline’
+     Like the ‘:match’ function, but taking into account inline values
+     and widgets.
 
-   Syntax:
+8.1.22 The ‘group’ Widget
+-------------------------
+
+Syntax:
 
      TYPE ::= (group [KEYWORD ARGUMENT]... TYPE...)
 
-   The value is a list, with one member for each TYPE.
+   A widget to group other widgets.  Its super is the ‘default’ widget.
 
-6 Sexp Types
-************
+   Its value is a list, with one member for each TYPE.
+
+   It overrides the following properties:
+
+‘:convert-widget’
+     As other composite widgets, a function that takes care of
+     converting each widget in TYPE.
+
+‘:copy’
+     A function to copy the types given in TYPE.
+
+‘:format’
+     By default, displays a newline character and its value.
+
+‘:value-create’
+     A function to create each of its components.
+
+‘:value-get’
+     The same function used by the ‘editable-list’ widget.
+
+‘:default-get’
+     A function that returns a list whose members are the default values
+     of each widget it groups.
+
+‘:validate’
+     This widget validates if all of its children validate.
+
+‘:match’
+     This widget matches a value that matches each of its components.
+
+‘:match-inline’
+     As ‘:match’, but taking into account widgets and values that are
+     inline.
+
+8.1.23 The ‘documentation-string’ Widget
+----------------------------------------
+
+Syntax:
+
+     TYPE ::= (documentation-string [KEYWORD ARGUMENT]... VALUE)
+
+   A widget to represent a documentation string.  Its super is the
+‘item’ widget.
+
+   It either overrides or adds the following properties:
+
+‘:format’
+     By default, insert its value.
+
+‘:value-create’
+     Function to insert a documentation string, possibly hiding part of
+     the documentation if its large.
+
+     To show or hide the rest of the documentation, uses a ‘visibility’
+     widget.
+
+‘:action’
+     Function to toggle showing the documentation upon an event.
+
+‘:visibility-widget’
+     A symbol, the type of the widget to use for the visibility widget.
+
+     This is, by default, the symbol ‘visibility’.
+
+8.2 Sexp Types
+==============
 
 A number of widgets for editing “s-expressions” (Lisp types), sexp for
 short, are also available.  These basically fall in several categories
 described in this section.
 
-6.1 The Constant Widgets
-========================
+8.2.1 The Constant Widgets
+--------------------------
 
 The ‘const’ widget can contain any Lisp expression, but the user is
 prohibited from editing it, which is mainly useful as a component of one
@@ -958,18 +2077,24 @@
 
      TYPE ::= (const [KEYWORD ARGUMENT]...  [ VALUE ])
 
-   The VALUE, if present, is used to initialize the ‘:value’ property
-and can be any s-expression.
+   Its super is the ‘item’ widget.  The VALUE, if present, is used to
+initialize the ‘:value’ property and can be any s-expression.
 
  -- Widget: const
      This will display any valid s-expression in an immutable part of
      the buffer.
 
+     It overrides the ‘:prompt-value’ function, to avoid prompting and
+     just return the widget’s value.
+
    There are two variations of the ‘const’ widget, namely
 ‘variable-item’ and ‘function-item’.  These should contain a symbol with
-a variable or function binding.  The major difference from the ‘const’
-widget is that they will allow the user to see the variable or function
-documentation for the symbol.
+a variable or function binding, respectively.  The major difference from
+the ‘const’ widget is that they will allow the user to see the variable
+or function documentation for the symbol.
+
+   This is accomplished via using the ‘%h’ format escape, and adding an
+appropiate ‘:documentation-property’ function for each widget.
 
  -- Widget: variable-item
      An immutable symbol that is bound as a variable.
@@ -977,8 +2102,8 @@
  -- Widget: function-item
      An immutable symbol that is bound as a function.
 
-6.2 Generic Sexp Widget
-=======================
+8.2.2 Generic Sexp Widget
+-------------------------
 
 The ‘sexp’ widget can contain any Lisp expression, and allows the user
 to edit it inline in the buffer.
@@ -988,74 +2113,165 @@
      TYPE ::= (sexp [KEYWORD ARGUMENT]...  [ VALUE ])
 
  -- Widget: sexp
-     This will allow you to edit any valid s-expression in an editable
-     buffer field.
+     This widget represents an editable field that’s useful to edit any
+     valid s-expression.
 
      The ‘sexp’ widget takes the same keyword arguments as the
      ‘editable-field’ widget.  *Note editable-field::.
 
-6.3 Atomic Sexp Widgets
-=======================
+     Its default value is ‘nil’.
+
+ -- Widget: restricted-sexp
+     A widget to edit Lisp expressions restricted to certain values or
+     types.  Its super is the ‘sexp’ widget.
+
+     It works just like the sexp widget, but it overrides the ‘:match’
+     function to match for certain values.  To use this widget, either
+     you must define a ‘:match’ function or give a ‘:match-alternatives’
+     property.  The ‘:match-alternatives’ property holds a list of
+     predicate functions to call when checking if a given value matches
+     the widget.  Each predicate function will be called with one
+     argument, the value to be matched, and should return non-‘nil’ on
+     success.
+
+     As an example, the ‘integer’ widget overrides ‘:match-alternatives’
+     to ‘(integerp)’.
+
+8.2.3 Atomic Sexp Widgets
+-------------------------
 
 The atoms are s-expressions that do not consist of other s-expressions.
 For example, a string, a file name, or a symbol are atoms, while a list
-is a composite type.  You can edit the value of an atom with the
-following widgets.
+is a composite type.  You can edit the value of an atom with the widgets
+described in this section.
 
-   The syntax for all the atoms are:
+   The syntax for all the atoms is:
 
      TYPE ::= (CONSTRUCT [KEYWORD ARGUMENT]...  [ VALUE ])
 
    The VALUE, if present, is used to initialize the ‘:value’ property
-and must be an expression of the same type as the widget.  That is, the
-string widget can only be initialized with a string.
+and must be an expression of the same type as the widget.  That is, for
+example, the string widget can only be initialized with a string.
 
    All the atom widgets take the same keyword arguments as the
 ‘editable-field’ widget.  *Note editable-field::.
 
  -- Widget: string
-     Allows you to edit a string in an editable field.
+     An editable field widget that can represent any Lisp string.
+
+     It offers completion via the ispell library and the ‘:complete’
+     property.
 
  -- Widget: regexp
-     Allows you to edit a regular expression in an editable field.
+     An editable field widget that can represent a regular expression.
+
+     Overrides the ‘:match’ and the ‘:validate’ properties to check that
+     the value is a valid regexp.
 
  -- Widget: character
-     Allows you to enter a character in an editable field.
+     An editable field widget that can represent a character.
+
+     The character widget represents some characters (like the newline
+     character) in a special manner, to make it easier for the user to
+     see what’s the content of the character field.
 
  -- Widget: file
-     Allows you to edit a file name in an editable field.
+     A widget for editing file names.
 
      Keywords:
+     ‘:completions’
+          Offers file name completion to the user.
+
+     ‘:prompt-value’
+          A function to read a file name from the minibuffer.
+
      ‘:must-match’
-          If this is set to non-‘nil’, only existing file names will be
-          allowed in the minibuffer.
+          If this is set to non-‘nil’, only existing file names are
+          allowed when prompting for a value in the minibuffer.
+
+     ‘:match’
+          The widget matches if the value is a string, and the file
+          whose name is that string is an existing file, or if
+          ‘:must-match’ is ‘nil’.
+
+     ‘:validate’
+          The widget is valid if its value matches.
 
  -- Widget: directory
-     Allows you to edit a directory name in an editable field.  Similar
-     to the ‘file’ widget.
+     A widget for editing directory names.
+
+     Its super is the ‘file’ widget, and it overrides the ‘:completions’
+     property, to offer completions only for directories.
 
  -- Widget: symbol
-     Allows you to edit a Lisp symbol in an editable field.
+     A widget for editing a Lisp symbol.
+
+     Its value by default is ‘nil’.
 
  -- Widget: function
-     Allows you to edit a lambda expression, or a function name with
-     completion.
+     A widget for editing a lambda expression, or a function name,
+     offering completion.  Its super is the ‘restricted-sexp’ widget.
 
  -- Widget: variable
-     Allows you to edit a variable name, with completion.
+     A widget for editing variable names, offering completion.  Its
+     super is the ‘symbol’ widget.
 
  -- Widget: integer
-     Allows you to edit an integer in an editable field.
+     A widget for editing integers in an editable field.  Its super is
+     the ‘restricted-sexp’ widget.
+
+     It has a default ‘:value’ of 0.
+
+ -- Widget: natnum
+     A widget for editing non-negative integers.  Its super is the
+     ‘restricted-sexp’ widget.
+
+     It has a default ‘:value’ of 0.
+
+ -- Widget: float
+     A widget for editing a floating point number.  Its super is the
+     ‘restricted-sexp’ widget.
+
+     It has a default ‘:value’ of 0.0.
 
  -- Widget: number
-     Allows you to edit a number in an editable field.
+     A widget for editing a number, either floating point or integer.
+     Its super is the ‘restricted-sexp’ widget.
+
+     It has a default ‘:value’ of 0.0.
 
  -- Widget: boolean
-     Allows you to edit a boolean.  In Lisp this means a variable which
-     is either ‘nil’ meaning false, or non-‘nil’ meaning true.
+     A widget for editing a boolean value.  Its super is the ‘toggle’
+     widget.
+
+     Its value may be ‘nil’, meaning false, or non-‘nil’, meaning true.
+
+ -- Widget: color
+     A widget to edit a color name.
+
+     In addition, shows a sample that shows the selected color, if any.
+
+ -- Widget: other
+     A widget useful as the last item in a ‘choice’ widget, since it
+     matches any value.
+
+     Its super is the ‘sexp’ widget, and its ‘:value’ is ‘other’, by
+     default.
+
+ -- Widget: coding-system
+     A widget that can represent a coding system name, offering
+     completions.  *Note (elisp)Coding Systems::.  Its super is the
+     ‘symbol’ widget.
+
+     It has a default value of ‘undecided’.
+
+ -- Widget: key
+     A widget to represent a key sequence.
+
+     It uses a special keymap as the ‘:keymap’.
 
-6.4 Composite Sexp Widgets
-==========================
+8.2.4 Composite Sexp Widgets
+----------------------------
 
 The syntax for the composite widget construct is:
 
@@ -1065,34 +2281,50 @@
 be displayed in the buffer, and will be editable by the user.
 
  -- Widget: cons
+     A widget to edit cons-cell values.  Its super is the ‘group’
+     widget.
+
      The value of a ‘cons’ widget must be a cons-cell whose CAR and CDR
      have two specified types.  It uses this syntax:
 
           TYPE ::= (cons [KEYWORD ARGUMENT]...  CAR-TYPE CDR-TYPE)
 
  -- Widget: choice
-     The value matched by a ‘choice’ widget must have one of a fixed set
-     of types.  The widget’s syntax is as follows:
+     A widget to hold a value of one of a fixed set of types.  Its super
+     is the ‘menu-choice’ widget.
+
+     The widget’s syntax is as follows:
 
           TYPE ::= (choice [KEYWORD ARGUMENT]...  TYPE ... )
 
      The value of a ‘choice’ widget can be anything that matches any of
      the TYPES.
 
+     This widget only displays the widget that corresponds to the
+     current choice.
+
+ -- Widget: radio
+     A widget to hold a value of one of a fixed set of options.  Its
+     super is the ‘radio-button-choice’ widget.
+
  -- Widget: list
+     A widget to edit a list value.  Its super is the ‘group’ widget.
+
      The value of a ‘list’ widget must be a list whose element types
      match the specified component types:
 
           TYPE ::= (list [KEYWORD ARGUMENT]...  COMPONENT-TYPE...)
 
-     Thus, ‘(list string number)’ matches lists of two elements, the
-     first being a string and the second being a number.
+     Thus, for example, ‘(list string number)’ matches lists of two
+     elements, the first being a string and the second being a number.
 
  -- Widget: vector
+     A widget to edit a vector value.  Its super is the ‘group’ widget.
+
      The ‘vector’ widget is like the ‘list’ widget but matches vectors
-     instead of lists.  Thus, ‘(vector string number)’ matches vectors
-     of two elements, the first being a string and the second being a
-     number.
+     instead of lists.  Thus, for example, ‘(vector string number)’
+     matches vectors of two elements, the first being a string and the
+     second being a number.
 
    The above suffice for specifying fixed size lists and vectors.  To
 get variable length lists and vectors, you can use a ‘choice’, ‘set’, or
@@ -1117,9 +2349,13 @@
 to explain it here, I’ll just suggest you meditate over it for a while.
 
  -- Widget: set
-     Specifies a type whose values are the lists whose elements all
-     belong to a given set.  The order of elements of the list is not
-     significant.  Here’s the syntax:
+     A widget to hold a list of members from a fixed set.  Its super is
+     the ‘checklist’ widget.
+
+     Its value is a list where the elements all belong to a given set.
+     The order of elements of the list is not significant.
+
+     Here’s the syntax:
 
           TYPE ::= (set [KEYWORD ARGUMENT]...  PERMITTED-ELEMENT ... )
 
@@ -1128,89 +2364,47 @@
 
  -- Widget: repeat
      Specifies a list of any number of elements that fit a certain type.
+     Its super is the ‘editable-list’ widget.
 
           TYPE ::= (repeat [KEYWORD ARGUMENT]...  TYPE)
 
-7 Properties
-************
-
-You can examine or set the value of a widget by using the widget object
-that was returned by ‘widget-create’.
-
- -- Function: widget-value widget
-     Return the current value contained in WIDGET.  It is an error to
-     call this function on an uninitialized widget.
-
- -- Function: widget-value-set widget value
-     Set the value contained in WIDGET to VALUE.  It is an error to call
-     this function with an invalid VALUE.
+ -- Widget: plist
+     A widget to edit property lists.  Its super is the ‘list’ widget.
 
-   *Important:* You _must_ call ‘widget-setup’ after modifying the value
-of a widget before the user is allowed to edit the widget again.  It is
-enough to call ‘widget-setup’ once if you modify multiple widgets.  This
-is currently only necessary if the widget contains an editing field, but
-may be necessary for other widgets in the future.
+     It recognizes the following properties:
 
-   If your application needs to associate some information with the
-widget objects, for example a reference to the item being edited, it can
-be done with ‘widget-put’ and ‘widget-get’.  The property names must
-begin with a ‘:’.
+     ‘:options’
+          A given set of recommended key-value values for the ‘plist’
+          widget.  Each option shows up as a checklist item.
 
- -- Function: widget-put widget property value
-     In WIDGET set PROPERTY to VALUE.  PROPERTY should be a symbol,
-     while VALUE can be anything.
+     ‘:key-type’
+          The widget type to use for the plist keys.  By default, it
+          uses the ‘symbol’ widget.
 
- -- Function: widget-get widget property
-     In WIDGET return the value for PROPERTY.  PROPERTY should be a
-     symbol, the value is what was last set by ‘widget-put’ for
-     PROPERTY.
+     ‘:value-type’
+          The widget type to use for the plist values.  By default, it
+          uses the ‘sexp’ widget.
 
- -- Function: widget-member widget property
-     Non-‘nil’ if WIDGET has a value (even ‘nil’) for property PROPERTY.
+ -- Widget: alist
+     A widget to edit association lists.  Its super is the ‘list’
+     widget.
 
- -- Function: widget-apply widget property &rest args
-     Apply the value of PROPERTY to WIDGET, passing ARGS as additional
-     arguments to the function.  Return the result of that function
-     call.
+     It recognizes the same properties that the ‘plist’ widget, with the
+     difference that the ‘:key-type’ uses by default a ‘sexp’ widget.
 
-   Occasionally it can be useful to know which kind of widget you have,
-i.e., the name of the widget type you gave when the widget was created.
+   Most composite widgets do not allow for recursion.  That is, none of
+the contained widgets may be of the same type that is currently being
+defined.  To allow for this kind of widgets, there’s the ‘lazy’ widget.
 
- -- Function: widget-type widget
-     Return the name of WIDGET, a symbol.
+ -- Widget: lazy
+     A base widget for recursive data structures.  Its super is the
+     ‘default’ widget.
 
-   Widgets can be in two states: active, which means they are modifiable
-by the user, or inactive, which means they cannot be modified by the
-user.  You can query or set the state with the following code:
-
-     ;; Examine if WIDGET is active or not.
-     (if (widget-apply WIDGET :active)
-         (message "Widget is active.")
-       (message "Widget is inactive.")
-
-     ;; Make WIDGET inactive.
-     (widget-apply WIDGET :deactivate)
-
-     ;; Make WIDGET active.
-     (widget-apply WIDGET :activate)
-
-   A widget is inactive if it, or any of its ancestors (found by
-following the ‘:parent’ link), have been deactivated.  To make sure a
-widget is really active, you must therefore activate both it and all its
-ancestors.
-
-     (while widget
-       (widget-apply widget :activate)
-       (setq widget (widget-get widget :parent)))
-
-   You can check if a widget has been made inactive by examining the
-value of the ‘:inactive’ keyword.  If this is non-‘nil’, the widget
-itself has been deactivated.  This is different from using the ‘:active’
-keyword, in that the latter tells you if the widget *or* any of its
-ancestors have been deactivated.  Do not attempt to set the ‘:inactive’
-keyword directly.  Use the ‘:activate’ ‘:deactivate’ keywords instead.
+     When instantiated, it contains a single inferior widget of the
+     widget type specified in the ‘:type’ property.  Its value is the
+     same as the value of this inferior widget.
 
-8 Defining New Widgets
+9 Defining New Widgets
 **********************
 
 You can define specialized widgets with ‘define-widget’.  It allows you
@@ -1218,15 +2412,24 @@
 component widgets and new default values for the keyword arguments.
 
  -- Function: define-widget name class doc &rest args
-     Define a new widget type named NAME from ‘class’.
+     Define a new widget type named NAME that derives from CLASS.
 
-     NAME and class should both be symbols, ‘class’ should be one of the
-     existing widget types.
+     NAME and CLASS should both be symbols, and CLASS should be one of
+     the existing widget types.
 
      The third argument DOC is a documentation string for the widget.
 
-     After the new widget has been defined, the following two calls will
-     create identical widgets:
+     ARGS should be key-value pairs, overriding keyword values of CLASS,
+     or adding new recognized keywords for NAME.
+
+     Usually, you’ll want to derive from an existing widget type, like
+     the ‘editable-field’ widget, or the ‘default’ widget, but it’s also
+     possible to derive from nothing, by passing a value of ‘nil’ as
+     CLASS.  Note that if you do this, you’re entirely responsible for
+     defining a whole new default behavior for your widgets.
+
+     After using this function, the following two calls will create
+     identical widgets:
 
         •      (widget-create NAME)
 
@@ -1239,147 +2442,61 @@
    If you only want to specify defaults for keywords with no complex
 conversions, you can use ‘identity’ as your conversion function.
 
-   The following additional keyword arguments are useful when defining
-new widgets:
+   When defining new widgets, the ‘:convert-widget’ property might be
+useful:
+
 ‘:convert-widget’
      Function to convert a widget type before creating a widget of that
-     type.  It takes a widget type as an argument, and returns the
-     converted widget type.  When a widget is created, this function is
-     called for the widget type and all the widget’s parent types, most
-     derived first.
-
-     The following predefined functions can be used here:
-
-      -- Function: widget-types-convert-widget widget
-          Convert ‘:args’ as widget types in WIDGET.
-
-      -- Function: widget-value-convert-widget widget
-          Initialize ‘:value’ from ‘:args’ in WIDGET.
-
-‘:copy’
-     Function to deep copy a widget type.  It takes a shallow copy of
-     the widget type as an argument (made by ‘copy-sequence’), and
-     returns a deep copy.  The purpose of this is to avoid having
-     different instances of combined widgets share nested attributes.
-
-     The following predefined functions can be used here:
-
-      -- Function: widget-types-copy widget
-          Copy ‘:args’ as widget types in WIDGET.
-
-‘:value-to-internal’
-     Function to convert the value to the internal format.  The function
-     takes two arguments, a widget and an external value, and returns
-     the internal value.  The function is called on the present ‘:value’
-     when the widget is created, and on any value set later with
-     ‘widget-value-set’.
+     type.
 
-‘:value-to-external’
-     Function to convert the value to the external format.  The function
-     takes two arguments, a widget and an internal value, and returns
-     the external value.
-
-‘:create’
-     Function to create a widget from scratch.  The function takes one
-     argument, a widget type, and creates a widget of that type, inserts
-     it in the buffer, and returns a widget object.
-
-‘:delete’
-     Function to delete a widget.  The function takes one argument, a
-     widget, and should remove all traces of the widget from the buffer.
-
-     The default value is:
-
-      -- Function: widget-default-delete widget
-          Remove WIDGET from the buffer.  Delete all ‘:children’ and
-          ‘:buttons’ in WIDGET.
-
-     In most cases you should not change this value, but instead use
-     ‘:value-delete’ to make any additional cleanup.
-
-‘:value-create’
-     Function to expand the ‘%v’ escape in the format string.  It will
-     be called with the widget as its argument and should insert a
-     representation of the widget’s value in the buffer.
-
-     Nested widgets should be listed in ‘:children’ or ‘:buttons’ to
-     make sure they are automatically deleted.
-
-‘:value-delete’
-     Should remove the representation of the widget’s value from the
-     buffer.  It will be called with the widget as its argument.  It
-     doesn’t have to remove the text, but it should release markers and
-     delete nested widgets if these are not listed in ‘:children’ or
-     ‘:buttons’.
-
-‘:value-get’
-     Function to extract the value of a widget, as it is displayed in
-     the buffer.
+     It takes a widget type as an argument, and returns the converted
+     widget type.  When a widget is created, this function is called for
+     the widget type and all the widget’s parent types, most derived
+     first.
 
-     The following predefined function can be used here:
+     The predefined functions ‘widget-types-convert-widget’ and
+     ‘widget-value-convert-widget’ can be used here.
 
-      -- Function: widget-value-value-get widget
-          Return the ‘:value’ property of WIDGET.
-
-‘:format-handler’
-     Function to handle unknown ‘%’ escapes in the format string.  It
-     will be called with the widget and the character that follows the
-     ‘%’ as arguments.  You can set this to allow your widget to handle
-     non-standard escapes.
-
-     You should end up calling ‘widget-default-format-handler’ to handle
-     unknown escape sequences, which will handle the ‘%h’ and any future
-     escape sequences, as well as give an error for unknown escapes.
-
-‘:action’
-     Function to handle user initiated events.  By default, ‘:notify’
-     the parent.
+10 Inspecting Widgets
+*********************
 
-     The following predefined function can be used here:
+There is a separate package to browse widgets, in ‘wid-browse.el’.  This
+is intended to help programmers who want to examine the content of a
+widget.  The browser shows the value of each keyword, but uses links for
+certain keywords such as ‘:parent’, which avoids printing cyclic
+structures.
 
-      -- Function: widget-parent-action widget &optional event
-          Tell ‘:parent’ of WIDGET to handle the ‘:action’.  Optional
-          EVENT is the event that triggered the action.
+ -- Command: widget-browse WIDGET
+     Create a widget browser for WIDGET.
 
-‘:prompt-value’
-     Function to prompt for a value in the minibuffer.  The function
-     should take four arguments, WIDGET, PROMPT, VALUE, and UNBOUND and
-     should return a value for widget entered by the user.  PROMPT is
-     the prompt to use.  VALUE is the default value to use, unless
-     UNBOUND is non-‘nil’, in which case there is no default value.  The
-     function should read the value using the method most natural for
-     this widget, and does not have to check that it matches.
+     When called interactively, prompt for WIDGET.
 
-   If you want to define a new widget from scratch, use the ‘default’
-widget as its base.
+ -- Command: widget-browse-other-window WIDGET
+     Create a widget browser for WIDGET and show it in another window.
 
- -- Widget: default
-     Widget used as a base for other widgets.
+     When called interactively, prompt for WIDGET.
 
-     It provides most of the functionality that is referred to as “by
-     default” in this text.
+ -- Command: widget-browse-at POS
+     Create a widget browser for the widget at POS.
 
-9 Widget Browser
-****************
+     When called interactively, use the position of point.
 
-There is a separate package to browse widgets.  This is intended to help
-programmers who want to examine the content of a widget.  The browser
-shows the value of each keyword, but uses links for certain keywords
-such as ‘:parent’, which avoids printing cyclic structures.
+   In addition, there’s a function to describe the widget at point.
 
- -- Command: widget-browse WIDGET
-     Create a widget browser for WIDGET.  When called interactively,
-     prompt for WIDGET.
+ -- Command: widget-describe &optional widget-or-pos
+     Describe the widget at point.
 
- -- Command: widget-browse-other-window WIDGET
-     Create a widget browser for WIDGET and show it in another window.
-     When called interactively, prompt for WIDGET.
+     When called from Lisp, WIDGET-OR-POS might be the widget to
+     describe or a buffer position where a widget is present.  If
+     WIDGET-OR-POS is ‘nil’, the widget to describe is the widget at
+     point.
 
- -- Command: widget-browse-at POS
-     Create a widget browser for the widget at POS.  When called
-     interactively, use the position of point.
+     This command sets up a help buffer for providing information about
+     the widget, mainly its ‘:action’ and ‘:mouse-down-action’
+     functions, and provides links to describe it in more detail using
+     the ‘widget-browse’ commands described above.
 
-10 Widget Minor Mode
+11 Widget Minor Mode
 ********************
 
 There is a minor mode for manipulating widgets in major modes that don’t
@@ -1393,16 +2510,26 @@
  -- Variable: widget-minor-mode-keymap
      Keymap used in ‘widget-minor-mode’.
 
-11 Utilities
+12 Utilities
 ************
 
+Here we describe some utility functions that don’t really have a place
+earlier in this manual.
+
  -- Function: widget-prompt-value widget prompt [ value unbound ]
      Prompt for a value matching WIDGET, using PROMPT.  The current
      value is assumed to be VALUE, unless UNBOUND is non-‘nil’.
 
+     Converts WIDGET before prompting, and for prompting it uses the
+     ‘:prompt-value’ function.  This function returns the user “answer”,
+     and it’s an error if that answer doesn’t match the widget, as with
+     the ‘:match’ function.
+
+     If the answer matches the widget, returns the answer.
+
  -- Function: widget-get-sibling widget
-     Get the item which WIDGET is assumed to toggle.  This is only
-     meaningful for radio buttons or checkboxes in a list.
+     Get the item which WIDGET should toggle.  This is only meaningful
+     for radio buttons or checkboxes in a list.
 
  -- Function: widget-choose title items &optional event
      Prompt the user to choose an item from a list of options.
@@ -1424,7 +2551,124 @@
      simplified format), then the return value is the VALUE of the
      chosen element.
 
-12 Wishlist
+ -- Function: widget-image-find image
+     Create a graphical button from IMAGE, an image or a file name sans
+     extension.
+
+     If IMAGE is a file name, the file should be in
+     ‘widget-image-directory’, or in a place where ‘find-image’ will
+     find it.
+
+ -- Function: widget-image-insert widget tag image
+     As part of WIDGET, insert the text TAG or, if supported, the image
+     IMAGE.
+
+     IMAGE should be as described in ‘widget-image-find’.
+
+ -- Function: widget-echo-help pos
+     Display help-echo text for the widget at POS.
+
+     Uses the value of ‘:help-echo’.  If it is a function, it calls it
+     to get a string.  Otherwise, it ‘eval’s it.
+
+13 Customization
+****************
+
+This chapter is about the customization options for the Widget library,
+for the end user.
+
+ -- Face: widget-field-face
+     Face used for other editing fields.
+
+ -- Face: widget-button-face
+     Face used for buttons.
+
+ -- User Option: widget-mouse-face
+     Face used for highlighting a button when the mouse pointer moves
+     across it.
+
+     The default value is ‘highlight’.
+
+ -- User Option: widget-image-directory
+     Directory where Widget should look for images.
+
+     Widget will look here for a file with the same name as specified
+     for the image, with either a ‘.xpm’ (if supported) or ‘.xbm’
+     extension.
+
+ -- User Option: widget-image-enable
+     If non-‘nil’, allow images to appear on displays where they are
+     supported.
+
+ -- User Option: widget-image-conversion
+     An alist to convert symbols from image formats to file name
+     suffixes.
+
+     Each element is a cons cell (FORMAT .  SUFFIX), where FORMAT is a
+     symbol that represents an image format and SUFFIX is its
+     correspondent suffix.
+
+ -- User Option: widget-button-prefix
+     String to prefix buttons.
+
+ -- User Option: widget-button-suffix
+     String to suffix buttons.
+
+ -- User Option: widget-push-button-prefix
+     String to prefix push buttons.
+
+ -- User Option: widget-push-button-suffix
+     String to suffix push buttons.
+
+ -- User Option: widget-link-prefix
+     String to prefix links.
+
+ -- User Option: widget-link-suffix
+     String to suffix links.
+
+ -- User Option: widget-choice-toggle
+     If non-‘nil’, toggle when there are just two options.
+
+     By default, its value is ‘nil’.
+
+ -- User Option: widget-documentation-links
+     If non-‘nil’, add hyperlinks to documentation strings.
+
+ -- User Option: widget-documentation-link-regexp
+     A regexp that matches potential links in documentation strings.
+     The link itself should match to the first group.
+
+ -- User Option: widget-documentation-link-p
+     A predicate function to test if a string is useful as a link.  The
+     function is called with one argument, a string, and should return
+     non-‘nil’ if there should be a link for that string.
+
+     By default, the value is ‘intern-soft’.
+
+ -- User Option: widget-documentation-link-type
+     A symbol that represents a widget type to use for links in
+     documentation strings.
+
+     By default, the value is ‘documentation-link’.
+
+ -- User Option: widget-menu-max-size
+     Maximum size for a popup menu.  By default, its value is 40.
+
+     If a function ask you to choose from a menu that is larger than
+     this value, it will use the minibuffer.
+
+ -- User Option: widget-menu-max-shortcuts
+     Largest number of items for which it works to choose one with a
+     character.
+
+     For a larger number, use the minibuffer.
+
+ -- User Option: widget-menu-minibuffer-flag
+     Whether to use the minibuffer to ask for a choice.
+
+     If ‘nil’, the default, read a single character.
+
+14 Wishlist
 ***********
 
    • It should be possible to add or remove items from a list with ‘C-k’
@@ -1449,12 +2693,6 @@
 
    • Find a way to make glyphs look inactive.
 
-   • Add ‘property-list’ widget.
-
-   • Add ‘association-list’ widget.
-
-   • Add ‘key-binding’ widget.
-
    • Add ‘widget’ widget for editing widget specifications.
 
    • Find clean way to implement variable length list.  See
@@ -1951,229 +3189,318 @@
 
 * Menu:
 
-* action keyword:                        Defining New Widgets.
-                                                             (line 1333)
-* activate a widget:                     Widget Properties.  (line 1181)
-* active widget:                         Widget Properties.  (line 1181)
-* append-button-args keyword:            editable-list.      (line  919)
-* args keyword:                          menu-choice.        (line  731)
+* action keyword:                        Widget Gallery.     (line 1124)
+* activate a widget:                     Widget Gallery.     (line 1083)
+* activate keyword:                      Widget Gallery.     (line 1116)
+* active keyword:                        Widget Gallery.     (line 1077)
+* active widget:                         Widget Gallery.     (line 1083)
+* alist:                                 composite.          (line 2387)
+* append-button-args keyword:            editable-list.      (line 1932)
+* args keyword:                          menu-choice.        (line 1538)
 * args keyword <1>:                      radio-button-choice.
-                                                             (line  771)
-* args keyword <2>:                      checklist.          (line  885)
-* args keyword <3>:                      editable-list.      (line  928)
-* atomic sexp widget:                    atoms.              (line  999)
-* basic widgets:                         Introduction.       (line   63)
-* boolean:                               atoms.              (line 1052)
-* browse-url-browser-function, and url-link widget: url-link.
-                                                             (line  629)
-* button widgets:                        User Interface.     (line  200)
+                                                             (line 1639)
+* args keyword <2>:                      checklist.          (line 1867)
+* args keyword <3>:                      editable-list.      (line 1954)
+* atomic sexp widget:                    atoms.              (line 2142)
+* basic widgets:                         Introduction.       (line   75)
+* boolean:                               atoms.              (line 2242)
+* button widgets:                        User Interface.     (line  202)
 * button-args keyword:                   radio-button-choice.
-                                                             (line  758)
-* button-args keyword <1>:               checklist.          (line  875)
-* button-face keyword:                   Basic Types.        (line  486)
-* button-prefix keyword:                 Basic Types.        (line  489)
-* button-suffix keyword:                 Basic Types.        (line  489)
+                                                             (line 1626)
+* button-args keyword <1>:               checklist.          (line 1857)
+* button-face keyword:                   Widget Gallery.     (line  915)
+* button-face-get keyword:               Widget Gallery.     (line 1050)
+* button-prefix keyword:                 Widget Gallery.     (line  918)
+* button-suffix keyword:                 Widget Gallery.     (line  918)
 * buttons keyword:                       radio-button-choice.
-                                                             (line  762)
-* buttons keyword <1>:                   checklist.          (line  879)
-* buttons keyword <2>:                   editable-list.      (line  922)
-* case-fold keyword:                     menu-choice.        (line  720)
-* character:                             atoms.              (line 1021)
-* checkbox widget:                       checkbox.           (line  837)
-* checklist widget:                      checklist.          (line  847)
-* children keyword:                      menu-choice.        (line  724)
+                                                             (line 1630)
+* buttons keyword <1>:                   checklist.          (line 1861)
+* buttons keyword <2>:                   editable-list.      (line 1935)
+* case-fold keyword:                     menu-choice.        (line 1525)
+* character:                             atoms.              (line 2170)
+* checkbox widget:                       checkbox.           (line 1785)
+* checklist widget:                      checklist.          (line 1825)
+* children keyword:                      menu-choice.        (line 1531)
 * children keyword <1>:                  radio-button-choice.
-                                                             (line  765)
-* children keyword <2>:                  checklist.          (line  882)
-* children keyword <3>:                  editable-list.      (line  925)
-* choice:                                composite.          (line 1072)
-* choice keyword:                        menu-choice.        (line  728)
+                                                             (line 1633)
+* children keyword <2>:                  checklist.          (line 1864)
+* children keyword <3>:                  editable-list.      (line 1951)
+* choice:                                composite.          (line 2291)
+* choice keyword:                        menu-choice.        (line 1535)
 * choice keyword <1>:                    radio-button-choice.
-                                                             (line  768)
-* choice-item widget:                    choice-item.        (line  800)
-* composite sexp widgets:                composite.          (line 1059)
-* cons:                                  composite.          (line 1066)
-* const:                                 constants.          (line  963)
-* constant widgets:                      constants.          (line  952)
+                                                             (line 1636)
+* choice-item widget:                    choice-item.        (line 1683)
+* coding-system:                         atoms.              (line 2260)
+* color:                                 atoms.              (line 2248)
+* completions-function keyword:          Widget Gallery.     (line 1028)
+* composite sexp widgets:                composite.          (line 2275)
+* cons:                                  composite.          (line 2282)
+* const:                                 constants.          (line 2082)
+* constant widgets:                      constants.          (line 2071)
 * convert-widget keyword:                Defining New Widgets.
-                                                             (line 1243)
-* copy keyword:                          Defining New Widgets.
-                                                             (line 1258)
-* create keyword:                        Defining New Widgets.
-                                                             (line 1281)
-* deactivate a widget:                   Widget Properties.  (line 1181)
-* default:                               Defining New Widgets.
-                                                             (line 1355)
+                                                             (line 2447)
+* copy keyword:                          Widget Gallery.     (line 1067)
+* create keyword:                        Widget Gallery.     (line  782)
+* deactivate a widget:                   Widget Gallery.     (line 1083)
+* deactivate keyword:                    Widget Gallery.     (line 1120)
+* default:                               Widget Gallery.     (line  773)
+* default-get keyword:                   Widget Gallery.     (line  869)
 * define-widget:                         Defining New Widgets.
-                                                             (line 1219)
+                                                             (line 2413)
 * defining new widgets:                  Defining New Widgets.
-                                                             (line 1215)
-* delete keyword:                        Defining New Widgets.
-                                                             (line 1286)
-* delete-button-args keyword:            editable-list.      (line  916)
-* directory:                             atoms.              (line 1032)
-* doc keyword:                           Basic Types.        (line  503)
-* editable-field widget:                 editable-field.     (line  663)
-* editable-list widget:                  editable-list.      (line  891)
-* embedded buttons:                      User Interface.     (line  227)
+                                                             (line 2409)
+* delete keyword:                        Widget Gallery.     (line  792)
+* delete-button-args keyword:            editable-list.      (line 1929)
+* directory:                             atoms.              (line 2199)
+* doc keyword:                           Widget Gallery.     (line  937)
+* documentation-string widget:           documentation-string.
+                                                             (line 2034)
+* editable-field widget:                 editable-field.     (line 1378)
+* editable-list widget:                  editable-list.      (line 1897)
+* emacs-commentary-link widget:          emacs-commentary-link.
+                                                             (line 1332)
+* emacs-library-link widget:             emacs-library-link. (line 1319)
+* embedded buttons:                      User Interface.     (line  219)
 * entry-format keyword:                  radio-button-choice.
-                                                             (line  748)
-* entry-format keyword <1>:              checklist.          (line  858)
-* entry-format keyword <2>:              editable-list.      (line  900)
+                                                             (line 1613)
+* entry-format keyword <1>:              checklist.          (line 1847)
+* entry-format keyword <2>:              editable-list.      (line 1913)
 * example of using widgets:              Programming Example.
-                                                             (line  273)
-* external format:                       Basic Types.        (line  422)
-* extra-offset keyword:                  Basic Types.        (line  533)
-* file:                                  atoms.              (line 1024)
-* follow-link keyword:                   Basic Types.        (line  521)
-* format keyword:                        Basic Types.        (line  435)
-* format-handler keyword:                Defining New Widgets.
-                                                             (line 1323)
-* function:                              atoms.              (line 1039)
-* function-item:                         constants.          (line  976)
-* generic sexp widget:                   generic.            (line  982)
-* greedy keyword:                        checklist.          (line  868)
-* group widget:                          group.              (line  934)
-* help-echo keyword:                     Basic Types.        (line  513)
-* inactive widget:                       Widget Properties.  (line 1181)
-* indent keyword:                        Basic Types.        (line  525)
-* info-link widget:                      info-link.          (line  635)
-* insert-button-args keyword:            editable-list.      (line  913)
-* integer:                               atoms.              (line 1046)
-* internal format:                       Basic Types.        (line  422)
-* item widget:                           item.               (line  789)
-* keymap keyword:                        editable-field.     (line  691)
-* keyword arguments:                     Basic Types.        (line  420)
-* link widget:                           link.               (line  607)
-* list:                                  composite.          (line 1081)
-* match keyword:                         Basic Types.        (line  554)
-* menu-choice widget:                    menu-choice.        (line  708)
-* menu-tag keyword:                      Basic Types.        (line  544)
-* menu-tag-get keyword:                  Basic Types.        (line  548)
-* mouse-2 (on button widgets):           User Interface.     (line  210)
-* must-match keyword:                    atoms.              (line 1028)
+                                                             (line  253)
+* external format:                       Widget Gallery.     (line  807)
+* extra-offset keyword:                  Widget Gallery.     (line  973)
+* face-link widget:                      face-link.          (line 1294)
+* file:                                  atoms.              (line 2177)
+* file-link widget:                      file-link.          (line 1306)
+* float:                                 atoms.              (line 2230)
+* follow-link keyword:                   Widget Gallery.     (line  956)
+* format keyword:                        Widget Gallery.     (line  874)
+* format-handler keyword:                Widget Gallery.     (line 1039)
+* function:                              atoms.              (line 2210)
+* function-item:                         constants.          (line 2101)
+* function-link widget:                  function-link.      (line 1269)
+* generic sexp widget:                   generic.            (line 2107)
+* greedy keyword:                        checklist.          (line 1887)
+* group widget:                          group.              (line 1991)
+* help-echo keyword:                     Widget Gallery.     (line  947)
+* inactive widget:                       Widget Gallery.     (line 1083)
+* indent keyword:                        Widget Gallery.     (line  960)
+* info-link widget:                      info-link.          (line 1256)
+* insert-button-args keyword:            editable-list.      (line 1926)
+* integer:                               atoms.              (line 2218)
+* internal format:                       Widget Gallery.     (line  807)
+* item widget:                           item.               (line 1168)
+* key:                                   atoms.              (line 2267)
+* keymap keyword:                        editable-field.     (line 1400)
+* keyword arguments:                     Widget Gallery.     (line  780)
+* lazy:                                  composite.          (line 2398)
+* link widget:                           link.               (line 1207)
+* list:                                  composite.          (line 2309)
+* match keyword:                         Widget Gallery.     (line  989)
+* menu-choice widget:                    menu-choice.        (line 1498)
+* menu-tag keyword:                      Widget Gallery.     (line  977)
+* menu-tag-get keyword:                  Widget Gallery.     (line  981)
+* mouse-2 (on button widgets):           Widgets and the Buffer.
+                                                             (line  740)
+* mouse-down-action keyword:             Widget Gallery.     (line 1131)
+* mouse-face-get keyword:                Widget Gallery.     (line 1058)
+* must-match keyword:                    atoms.              (line 2187)
+* natnum:                                atoms.              (line 2224)
 * new widgets:                           Defining New Widgets.
-                                                             (line 1215)
-* notify keyword:                        Basic Types.        (line  537)
-* number:                                atoms.              (line 1049)
-* off-glyph keyword:                     toggle.             (line  829)
-* offset keyword:                        Basic Types.        (line  529)
-* on-glyph keyword:                      toggle.             (line  826)
-* option field tag:                      User Interface.     (line  220)
-* parent keyword:                        Basic Types.        (line  585)
-* prompt-value keyword:                  Defining New Widgets.
-                                                             (line 1343)
-* properties of widgets:                 Widget Properties.  (line 1136)
-* push-button widget:                    push-button.        (line  645)
+                                                             (line 2409)
+* notify keyword:                        Widget Gallery.     (line 1137)
+* number:                                atoms.              (line 2236)
+* off-glyph keyword:                     toggle.             (line 1732)
+* offset keyword:                        Widget Gallery.     (line  969)
+* on-glyph keyword:                      toggle.             (line 1728)
+* option field tag:                      User Interface.     (line  212)
+* other:                                 atoms.              (line 2253)
+* parent keyword:                        Widget Gallery.     (line 1018)
+* plist:                                 composite.          (line 2370)
+* prompt-value keyword:                  Widget Gallery.     (line 1148)
+* push-button widget:                    push-button.        (line 1345)
+* radio:                                 composite.          (line 2305)
 * radio-button-choice widget:            radio-button-choice.
-                                                             (line  737)
-* regexp:                                atoms.              (line 1018)
-* repeat:                                composite.          (line 1128)
-* secret keyword:                        editable-field.     (line  681)
-* set:                                   composite.          (line 1118)
-* sexp:                                  generic.            (line  989)
-* sexp types:                            Sexp Types.         (line  945)
-* sibling-args keyword:                  Basic Types.        (line  589)
-* size keyword:                          editable-field.     (line  673)
-* string:                                atoms.              (line 1015)
-* symbol:                                atoms.              (line 1036)
-* tab-order keyword:                     Basic Types.        (line  570)
-* tag keyword:                           Basic Types.        (line  506)
-* tag-glyph keyword:                     Basic Types.        (line  509)
-* text widget:                           text.               (line  701)
-* todo:                                  Widget Wishlist.    (line 1429)
-* toggle widget:                         toggle.             (line  813)
-* url-link widget:                       url-link.           (line  625)
-* utility functions for widgets:         Utilities.          (line 1398)
-* valid-regexp keyword:                  editable-field.     (line  686)
-* validate keyword:                      Basic Types.        (line  559)
-* value keyword:                         Basic Types.        (line  422)
-* value-create keyword:                  Defining New Widgets.
-                                                             (line 1299)
-* value-delete keyword:                  Defining New Widgets.
-                                                             (line 1307)
-* value-face keyword:                    editable-field.     (line  677)
-* value-get keyword:                     Defining New Widgets.
-                                                             (line 1314)
-* value-to-external keyword:             Defining New Widgets.
-                                                             (line 1276)
-* value-to-internal keyword:             Defining New Widgets.
-                                                             (line 1269)
-* variable:                              atoms.              (line 1043)
-* variable-item:                         constants.          (line  973)
-* vector:                                composite.          (line 1090)
-* void keyword:                          menu-choice.        (line  716)
-* widget browser:                        Widget Browser.     (line 1364)
-* widget buttons:                        User Interface.     (line  200)
-* widget library, why use it:            Introduction.       (line  103)
-* widget minor mode:                     Widget Minor Mode.  (line 1384)
-* widget properties:                     Widget Properties.  (line 1136)
-* widget-apply:                          Widget Properties.  (line 1170)
-* widget-backward:                       User Interface.     (line  267)
-* widget-browse:                         Widget Browser.     (line 1369)
-* widget-browse-at:                      Widget Browser.     (line 1377)
-* widget-browse-other-window:            Widget Browser.     (line 1373)
-* widget-button-click:                   User Interface.     (line  211)
-* widget-button-click <1>:               Setting Up the Buffer.
-                                                             (line  399)
-* widget-button-face:                    User Interface.     (line  249)
-* widget-button-prefix:                  Basic Types.        (line  446)
-* widget-button-press:                   User Interface.     (line  205)
-* widget-button-press <1>:               Setting Up the Buffer.
+                                                             (line 1589)
+* radio-button-toggle widget:            radio-button-toggle.
+                                                             (line 1750)
+* regexp:                                atoms.              (line 2164)
+* repeat:                                composite.          (line 2364)
+* restricted-sexp:                       generic.            (line 2123)
+* secret keyword:                        editable-field.     (line 1424)
+* set:                                   composite.          (line 2350)
+* sexp:                                  generic.            (line 2114)
+* sexp types:                            Sexp Types.         (line 2064)
+* sibling-args keyword:                  Widget Gallery.     (line 1022)
+* size keyword:                          editable-field.     (line 1414)
+* string:                                atoms.              (line 2158)
+* symbol:                                atoms.              (line 2205)
+* tab-order keyword:                     Widget Gallery.     (line 1004)
+* tag keyword:                           Widget Gallery.     (line  940)
+* tag-glyph keyword:                     Widget Gallery.     (line  943)
+* text widget:                           text.               (line 1479)
+* todo:                                  Widget Wishlist.    (line 2673)
+* toggle widget:                         toggle.             (line 1705)
+* url-link widget:                       url-link.           (line 1244)
+* utility functions for widgets:         Utilities.          (line 2515)
+* valid-regexp keyword:                  editable-field.     (line 1431)
+* validate keyword:                      Widget Gallery.     (line  994)
+* value keyword:                         Widget Gallery.     (line  807)
+* value-create keyword:                  Widget Gallery.     (line  835)
+* value-delete keyword:                  Widget Gallery.     (line  841)
+* value-face keyword:                    editable-field.     (line 1419)
+* value-get keyword:                     Widget Gallery.     (line  851)
+* value-inline keyword:                  Widget Gallery.     (line  863)
+* value-set keyword:                     Widget Gallery.     (line  855)
+* value-to-external keyword:             Widget Gallery.     (line  829)
+* value-to-internal keyword:             Widget Gallery.     (line  821)
+* variable:                              atoms.              (line 2214)
+* variable-item:                         constants.          (line 2098)
+* variable-link widget:                  variable-link.      (line 1282)
+* vector:                                composite.          (line 2320)
+* void keyword:                          menu-choice.        (line 1519)
+* widget browser:                        Inspecting Widgets. (line 2462)
+* widget buttons:                        User Interface.     (line  202)
+* widget creation, widget conversion:    Setting Up the Buffer.
                                                              (line  399)
-* widget-button-suffix:                  Basic Types.        (line  449)
-* widget-children-validate:              Basic Types.        (line  567)
-* widget-choose:                         Utilities.          (line 1406)
+* widget inheritance:                    Widgets Basics.     (line  355)
+* widget library, why use it:            Introduction.       (line  116)
+* widget minor mode:                     Widget Minor Mode.  (line 2501)
+* widget object:                         Widgets Basics.     (line  349)
+* widget properties:                     Widgets Basics.     (line  391)
+* widget syntax:                         Widget Gallery.     (line  754)
+* widget value:                          Widgets Basics.     (line  374)
+* widget-apply:                          Working with Widgets.
+                                                             (line  564)
+* widget-apply-action:                   Working with Widgets.
+                                                             (line  636)
+* widget-at:                             Working with Widgets.
+                                                             (line  558)
+* widget-backward:                       Widgets and the Buffer.
+                                                             (line  706)
+* widget-browse:                         Inspecting Widgets. (line 2468)
+* widget-browse-at:                      Inspecting Widgets. (line 2478)
+* widget-browse-other-window:            Inspecting Widgets. (line 2473)
+* widget-button-click:                   Widgets and the Buffer.
+                                                             (line  741)
+* widget-button-click <1>:               Widgets and the Buffer.
+                                                             (line  741)
+* widget-button-face:                    Customization.      (line 2582)
+* widget-button-prefix:                  Customization.      (line 2610)
+* widget-button-press:                   Widgets and the Buffer.
+                                                             (line  731)
+* widget-button-press <1>:               Widgets and the Buffer.
+                                                             (line  731)
+* widget-button-suffix:                  Customization.      (line 2613)
+* widget-child-validate:                 Working with Widgets.
+                                                             (line  647)
+* widget-child-value-get:                Working with Widgets.
+                                                             (line  605)
+* widget-child-value-inline:             Working with Widgets.
+                                                             (line  608)
+* widget-children-validate:              Working with Widgets.
+                                                             (line  653)
+* widget-children-value-delete:          Setting Up the Buffer.
+                                                             (line  482)
+* widget-choice-toggle:                  Customization.      (line 2628)
+* widget-choose:                         Utilities.          (line 2533)
+* widget-complete:                       Widgets and the Buffer.
+                                                             (line  722)
+* widget-convert:                        Setting Up the Buffer.
+                                                             (line  504)
+* widget-copy:                           Setting Up the Buffer.
+                                                             (line  494)
 * widget-create:                         Setting Up the Buffer.
-                                                             (line  374)
-* widget-default-delete:                 Defining New Widgets.
-                                                             (line 1292)
-* widget-default-format-handler:         Defining New Widgets.
-                                                             (line 1329)
+                                                             (line  414)
+* widget-create-child:                   Setting Up the Buffer.
+                                                             (line  443)
+* widget-create-child-and-convert:       Setting Up the Buffer.
+                                                             (line  433)
+* widget-create-child-value:             Setting Up the Buffer.
+                                                             (line  449)
+* widget-default-delete:                 Widget Gallery.     (line  800)
+* widget-default-format-handler:         Widget Gallery.     (line 1046)
+* widget-default-get:                    Working with Widgets.
+                                                             (line  592)
 * widget-delete:                         Setting Up the Buffer.
-                                                             (line  381)
-* widget-field-face:                     User Interface.     (line  194)
-* widget-field-keymap:                   editable-field.     (line  691)
-* widget-forward:                        User Interface.     (line  263)
-* widget-get:                            Widget Properties.  (line 1162)
-* widget-get-sibling:                    Utilities.          (line 1402)
-* widget-global-map:                     Setting Up the Buffer.
-                                                             (line  404)
-* widget-image-directory:                Basic Types.        (line  595)
-* widget-image-enable:                   Basic Types.        (line  600)
+                                                             (line  479)
+* widget-describe:                       Inspecting Widgets. (line 2485)
+* widget-documentation-link-p:           Customization.      (line 2640)
+* widget-documentation-link-regexp:      Customization.      (line 2636)
+* widget-documentation-link-type:        Customization.      (line 2647)
+* widget-documentation-links:            Customization.      (line 2633)
+* widget-echo-help:                      Utilities.          (line 2567)
+* widget-end-of-line:                    Widgets and the Buffer.
+                                                             (line  713)
+* widget-field-activate:                 Widgets and the Buffer.
+                                                             (line  726)
+* widget-field-at:                       Working with Widgets.
+                                                             (line  561)
+* widget-field-face:                     Customization.      (line 2579)
+* widget-field-keymap:                   editable-field.     (line 1400)
+* widget-forward:                        Widgets and the Buffer.
+                                                             (line  702)
+* widget-get:                            Working with Widgets.
+                                                             (line  548)
+* widget-get-sibling:                    Utilities.          (line 2529)
+* widget-global-map:                     Widgets and the Buffer.
+                                                             (line  692)
+* widget-image-conversion:               Customization.      (line 2602)
+* widget-image-directory:                Customization.      (line 2591)
+* widget-image-enable:                   Customization.      (line 2598)
+* widget-image-find:                     Utilities.          (line 2553)
+* widget-image-insert:                   Utilities.          (line 2561)
 * widget-insert:                         Setting Up the Buffer.
-                                                             (line  393)
-* widget-keymap:                         Setting Up the Buffer.
-                                                             (line  399)
-* widget-link-prefix:                    link.               (line  616)
-* widget-link-suffix:                    link.               (line  619)
-* widget-member:                         Widget Properties.  (line 1167)
-* widget-minor-mode:                     Widget Minor Mode.  (line 1388)
-* widget-minor-mode-keymap:              Widget Minor Mode.  (line 1392)
-* widget-mouse-face:                     User Interface.     (line  252)
-* widget-parent-action:                  Defining New Widgets.
-                                                             (line 1339)
-* widget-prompt-value:                   Utilities.          (line 1398)
-* widget-push-button-prefix:             push-button.        (line  654)
-* widget-push-button-suffix:             push-button.        (line  657)
-* widget-put:                            Widget Properties.  (line 1158)
+                                                             (line  518)
+* widget-keymap:                         Widgets and the Buffer.
+                                                             (line  681)
+* widget-kill-line:                      Widgets and the Buffer.
+                                                             (line  718)
+* widget-link-prefix:                    Customization.      (line 2622)
+* widget-link-suffix:                    Customization.      (line 2625)
+* widget-member:                         Working with Widgets.
+                                                             (line  544)
+* widget-menu-max-shortcuts:             Customization.      (line 2659)
+* widget-menu-max-size:                  Customization.      (line 2653)
+* widget-menu-minibuffer-flag:           Customization.      (line 2665)
+* widget-minor-mode:                     Widget Minor Mode.  (line 2505)
+* widget-minor-mode-keymap:              Widget Minor Mode.  (line 2509)
+* widget-mouse-face:                     Customization.      (line 2585)
+* widget-parent-action:                  Working with Widgets.
+                                                             (line  642)
+* widget-prompt-value:                   Utilities.          (line 2518)
+* widget-push-button-prefix:             Customization.      (line 2616)
+* widget-push-button-suffix:             Customization.      (line 2619)
+* widget-put:                            Working with Widgets.
+                                                             (line  554)
 * widget-radio-add-item:                 radio-button-choice.
-                                                             (line  778)
+                                                             (line 1672)
 * widget-setup:                          Setting Up the Buffer.
-                                                             (line  384)
-* widget-text-keymap:                    text.               (line  701)
-* widget-type:                           Widget Properties.  (line 1178)
-* widget-types-convert-widget:           Defining New Widgets.
-                                                             (line 1252)
-* widget-types-copy:                     Defining New Widgets.
-                                                             (line 1266)
-* widget-value:                          Widget Properties.  (line 1139)
-* widget-value-convert-widget:           Defining New Widgets.
-                                                             (line 1255)
-* widget-value-set:                      Widget Properties.  (line 1143)
-* widget-value-value-get:                Defining New Widgets.
-                                                             (line 1320)
-* widgets, basic types:                  Introduction.       (line   63)
+                                                             (line  466)
+* widget-text-keymap:                    text.               (line 1491)
+* widget-type:                           Working with Widgets.
+                                                             (line  537)
+* widget-type-default-get:               Working with Widgets.
+                                                             (line  601)
+* widget-type-match:                     Working with Widgets.
+                                                             (line  658)
+* widget-type-value-create:              Working with Widgets.
+                                                             (line  615)
+* widget-types-convert-widget:           Working with Widgets.
+                                                             (line  670)
+* widget-types-copy:                     Working with Widgets.
+                                                             (line  664)
+* widget-value:                          Working with Widgets.
+                                                             (line  570)
+* widget-value-convert-widget:           Working with Widgets.
+                                                             (line  624)
+* widget-value-set:                      Working with Widgets.
+                                                             (line  583)
+* widget-value-value-get:                Working with Widgets.
+                                                             (line  629)
+* widgetp:                               Working with Widgets.
+                                                             (line  534)
+* widgets, basic types:                  Introduction.       (line   75)
 * widgets, programming example:          Programming Example.
-                                                             (line  273)
+                                                             (line  253)
 

[-- Attachment #4: widget.texi.txt --]
[-- Type: text/plain, Size: 141967 bytes --]

The Emacs Widget Library
1 Introduction
2 User Interface
  2.1 Editable Text Fields
  2.2 Buttons
  2.3 Navigation
3 Programming Example
4 Widgets Basics
5 Setting Up the Buffer
6 Working with Widgets
7 Widgets and the Buffer
8 Widget Gallery
  8.1 Basic Types
    8.1.1 The ‘item’ Widget
    8.1.2 The ‘link’ Widget
    8.1.3 The ‘url-link’ Widget
    8.1.4 The ‘info-link’ Widget
    8.1.5 The ‘function-link’ Widget
    8.1.6 The ‘variable-link’ Widget
    8.1.7 The ‘face-link’ Widget
    8.1.8 The ‘file-link’ Widget
    8.1.9 The ‘emacs-library-link’ Widget
    8.1.10 The ‘emacs-commentary-link’ Widget
    8.1.11 The ‘push-button’ Widget
    8.1.12 The ‘editable-field’ Widget
    8.1.13 The ‘text’ Widget
    8.1.14 The ‘menu-choice’ Widget
    8.1.15 The ‘radio-button-choice’ Widget
    8.1.16 The ‘choice-item’ Widget
    8.1.17 The ‘toggle’ Widget
    8.1.18 The ‘radio-button-toggle’ Widget
    8.1.19 The ‘checkbox’ Widget
    8.1.20 The ‘checklist’ Widget
    8.1.21 The ‘editable-list’ Widget
    8.1.22 The ‘group’ Widget
    8.1.23 The ‘documentation-string’ Widget
  8.2 Sexp Types
    8.2.1 The Constant Widgets
    8.2.2 Generic Sexp Widget
    8.2.3 Atomic Sexp Widgets
    8.2.4 Composite Sexp Widgets
9 Defining New Widgets
10 Inspecting Widgets
11 Widget Minor Mode
12 Utilities
13 Customization
14 Wishlist
Appendix A GNU Free Documentation License
Index
The Emacs Widget Library
************************

Copyright © 2000–2023 Free Software Foundation, Inc.

     Permission is granted to copy, distribute and/or modify this
     document under the terms of the GNU Free Documentation License,
     Version 1.3 or any later version published by the Free Software
     Foundation; with no Invariant Sections, with the Front-Cover Texts
     being “A GNU Manual”, and with the Back-Cover Texts as in (a)
     below.  A copy of the license is included in the section entitled
     “GNU Free Documentation License”.

     (a) The FSF’s Back-Cover Text is: “You have the freedom to copy and
     modify this GNU manual.”

1 Introduction
**************

Most graphical user interface toolkits provide a number of standard user
interface controls (sometimes known as “widgets” or “gadgets”).  Emacs
doesn’t really support anything like this, except for an incredibly
powerful text “widget”.  On the other hand, Emacs does provide the
necessary primitives to implement many other widgets within a text
buffer.  The ‘widget’ package simplifies this task.

   The basic widgets are:

‘link’
     Areas of text with an associated action.  Intended for hypertext
     links embedded in text.
‘push-button’
     Like link, but intended for stand-alone buttons.
‘editable-field’
     An editable text field.  It can be either variable or fixed length.
‘menu-choice’
     Allows the user to choose one of multiple options from a menu,
     where each option is itself a widget.  Only the selected option is
     visible in the buffer.
‘radio-button-choice’
     Allows the user to choose one of multiple options by activating
     radio buttons.  The options are implemented as widgets.  All
     options are visible in the buffer, with the selected one marked as
     chosen.
‘item’
     A simple constant widget intended to be used in the ‘menu-choice’
     and ‘radio-button-choice’ widgets.
‘choice-item’
     A button item only intended for use in choices.  When invoked, the
     user will be asked to select another option from the choice widget.
‘toggle’
     A simple ‘on’/‘off’ switch.
‘checkbox’
     A checkbox (‘[ ]’/‘[X]’).
‘editable-list’
     Create an editable list.  The user can insert or delete items in
     the list.  Each list item is itself a widget.

   Now, of what possible use can support for widgets be in a text
editor?  I’m glad you asked.  The answer is that widgets are useful for
implementing forms.  A “form” in Emacs is a buffer where the user is
supposed to fill out a number of fields, each of which has a specific
meaning.  The user is not supposed to change or delete any of the text
between the fields.  Examples of forms in Emacs are the ‘forms’ package
(of course), the customize buffers, the mail and news compose modes, and
the HTML form support in the ‘w3’ browser.

   The advantages for a programmer of using the ‘widget’ package to
implement forms are:

  1. More complex fields than just editable text are supported.
  2. You can give the users immediate feedback if they enter invalid
     data in a text field, and sometimes prevent entering invalid data.
  3. You can have fixed sized fields, thus allowing multiple fields to
     be lined up in columns.
  4. It is simple to query or set the value of a field.
  5. Editing happens in the buffer, not in the mini-buffer.
  6. Packages using the library get a uniform look, making them easier
     for the user to learn.
  7. As support for embedded graphics improve, the widget library will
     be extended to use the GUI features.  This means that your code
     using the widget library will also use the new graphic features
     automatically.

2 User Interface
****************

A form consists of read only text for documentation and some fields,
where each field contains two parts, a tag and a value.  The tags are
used to identify the fields, so the documentation can refer to the ‘foo
field’, meaning the field tagged with ‘Foo’.  Here is an example form:

     Here is some documentation.

     Name: My Name     *Choose*: This option
     Address:  Some Place
     In some City
     Some country.

     See also _other work_ for more information.

     Numbers: count to three below
     [INS] [DEL] One
     [INS] [DEL] Eh, two?
     [INS] [DEL] Five!
     [INS]

     Select multiple:

     [X] This
     [ ] That
     [X] Thus

     Select one:

     (*) One
     ( ) Another One.
     ( ) A Final One.

     [Apply Form] [Reset Form]

   The top level widgets in this example are tagged ‘Name’, ‘Choose’,
‘Address’, ‘_other work_’, ‘Numbers’, ‘Select multiple’, ‘Select one’,
‘[Apply Form]’, and ‘[Reset Form]’.  There are basically two things the
user can do within a form, namely editing the editable text fields and
activating the buttons.

2.1 Editable Text Fields
========================

In the example, the value for the ‘Name’ is most likely displayed in an
editable text field, and so are values for each of the members of the
‘Numbers’ list.  All the normal Emacs editing operations are available
for editing these fields.  The only restriction is that each change you
make must be contained within a single editable text field.  For
example, capitalizing all text from the middle of one field to the
middle of another field is prohibited.

   Editable text fields are created by the ‘editable-field’ widget.

   The ‘:format’ keyword is useful for generating the necessary text;
for instance, if you give it a value of ‘"Name: %v "’, the ‘Name: ’ part
will provide the necessary separating text before the field and the
trailing space will provide the separating text after the field.  If you
don’t include the ‘:size’ keyword, the field will extend to the end of
the line, and the terminating newline will provide separation after.

   The editing text fields are highlighted with the ‘widget-field-face’
face, making them easy to find.

2.2 Buttons
===========

Some portions of the buffer have an associated “action”, which can be
“invoked” by a standard key or mouse command.  These portions are called
“buttons”.  The default commands for activating a button are
‘widget-button-press’ and ‘widget-button-click’.  The user typically
interacts with the buttons with a key, like <RET>, or with the mouse
buttons.

   There are several different kind of buttons, all of which are present
in the example:

_The Option Field Tags_
     When you invoke one of these buttons, you will be asked to choose
     between a number of different options.  This is how you edit an
     option field.  Option fields are created by the ‘menu-choice’
     widget.  In the example, ‘Choose’ is an option field tag.
_The ‘[INS]’ and ‘[DEL]’ buttons_
     Activating these will insert or delete elements from an editable
     list.  The list is created by the ‘editable-list’ widget.
_Embedded Buttons_
     The ‘_other work_’ is an example of an embedded button.  Embedded
     buttons are not associated with any fields, but can serve any
     purpose, such as implementing hypertext references.  They are
     usually created by the ‘link’ widget.
_The ‘[ ]’ and ‘[X]’ buttons_
     Activating one of these will convert it to the other.  This is
     useful for implementing multiple-choice fields.  You can create
     them with the ‘checkbox’ widget.
_The ‘( )’ and ‘(*)’ buttons_
     Only one radio button in a ‘radio-button-choice’ widget can be
     selected at any time.  When you invoke one of the unselected radio
     buttons, it will be selected and the previous selected radio button
     will become unselected.
_The ‘[Apply Form]’ and ‘[Reset Form]’ buttons_
     These are explicit buttons made with the ‘push-button’ widget.  The
     main difference from the ‘link’ widget is that the buttons will be
     displayed as GUI buttons when possible.

   To make them easier to locate, buttons are emphasized in the buffer
with a distinctive face, like ‘widget-button-face’ or
‘widget-mouse-face’.

2.3 Navigation
==============

You can use all the normal Emacs commands to move around in a form
buffer, plus you will have these additional commands to navigate from
widget to widget: ‘widget-forward’ and ‘widget-backward’.

3 Programming Example
*********************

Here is the code to implement the user interface example (*note User
Interface::).

     (require 'widget)

     (eval-when-compile
       (require 'wid-edit))

     (defvar widget-example-repeat)

     (defun widget-example ()
       "Create the widgets from the Widget manual."
       (interactive)
       (switch-to-buffer "*Widget Example*")
       (kill-all-local-variables)
       (make-local-variable 'widget-example-repeat)
       (let ((inhibit-read-only t))
         (erase-buffer))
       (remove-overlays)
       (widget-insert "Here is some documentation.\n\n")
       (widget-create 'editable-field
                      :size 13
                      :format "Name: %v " ; Text after the field!
                      "My Name")
       (widget-create 'menu-choice
                      :tag "Choose"
                      :value "This"
                      :help-echo "Choose me, please!"
                      :notify (lambda (widget &rest ignore)
                                (message "%s is a good choice!"
                                         (widget-value widget)))
                      '(item :tag "This option" :value "This")
                      '(choice-item "That option")
                      '(editable-field :menu-tag "No option" "Thus option"))
       (widget-create 'editable-field
                      :format "Address: %v"
                      "Some Place\nIn some City\nSome country.")
       (widget-insert "\nSee also ")
       (widget-create 'link
                      :notify (lambda (&rest ignore)
                                (widget-value-set widget-example-repeat
                                                  '("En" "To" "Tre"))
                                (widget-setup))
                      "other work")
       (widget-insert
         " for more information.\n\nNumbers: count to three below\n")
       (setq widget-example-repeat
             (widget-create 'editable-list
                            :entry-format "%i %d %v"
                            :notify
                            (lambda (widget &rest ignore)
                              (let ((old (widget-get widget
                                                     ':example-length))
                                    (new (length (widget-value widget))))
                                (unless (eq old new)
                                  (widget-put widget ':example-length new)
                                  (message "You can count to %d." new))))
                            :value '("One" "Eh, two?" "Five!")
                            '(editable-field :value "three")))
       (widget-insert "\n\nSelect multiple:\n\n")
       (widget-create 'checkbox t)
       (widget-insert " This\n")
       (widget-create 'checkbox nil)
       (widget-insert " That\n")
       (widget-create 'checkbox
                      :notify (lambda (&rest ignore) (message "Tickle"))
                      t)
       (widget-insert " Thus\n\nSelect one:\n\n")
       (widget-create 'radio-button-choice
                      :value "One"
                      :notify (lambda (widget &rest ignore)
                                (message "You selected %s"
                                         (widget-value widget)))
                      '(item "One") '(item "Another One.")
                      '(item "A Final One."))
       (widget-insert "\n")
       (widget-create 'push-button
                      :notify (lambda (&rest ignore)
                                (if (= (length
                                        (widget-value widget-example-repeat))
                                       3)
                                    (message "Congratulation!")
                                  (error "Three was the count!")))
                      "Apply Form")
       (widget-insert " ")
       (widget-create 'push-button
                      :notify (lambda (&rest ignore)
                                (widget-example))
                      "Reset Form")
       (widget-insert "\n")
       (use-local-map widget-keymap)
       (widget-setup))

4 Widgets Basics
****************

The Widget Library deals with widgets objects.  A widget object has
properties whose value may be anything, be it numbers, strings, symbols,
functions, etc.  Those properties are referred to as keywords and are
responsible for the way a widget is represented in a buffer, and control
the way a user or a program can interact with it.

   The library defines several widget types, and gives you a way to
define new types as well.  In addition, widgets can derive from other
types, creating a sort of widget inheritance.  In fact, all widgets
defined in the Widget Library share a common parent, the “default”
widget.  In this manual, when we talk about a default behavior, we
usually mean the behavior as defined by this ‘default’ widget.  *Note
Widget Gallery::, for a description of each defined widget.

   Defining a new type that derives from a previous one is not mandatory
to create widgets that work very different from a specified type.  When
creating a widget, you can override any default property, including
functions, that control the widget.  That is, you can specialize a
widget on creation, without having to define it as a new type of widget.

   In addition to the function for defining a widget, this library
provides functions to create widgets, query and change its properties,
respond to user events and destroy them.  The following sections
describe them.

   One important property of a widget is its “value”.  All widgets may
have a value, which is stored in a so-called “internal format”.  For the
rest of Emacs, the widget presents its value in a so-called “external
format”.  Both formats can be equal or different, and each widget is
responsible for defining how the conversion between each format should
happen.

   The value property is an important property for almost all widgets,
and perhaps more important for ‘editable-field’ widgets.  This type of
widgets allow the user to edit them via the usual editing commands in
Emacs.  They can also be edited programmatically.  *Important:* You
_must_ call ‘widget-setup’ after modifying the value of a widget before
the user is allowed to edit the widget again.  It is enough to call
‘widget-setup’ once if you modify multiple widgets.  This is currently
only necessary if the widget contains an editing field, but may be
necessary for other widgets in the future.

   If your application needs to associate some information with the
widget objects, for example a reference to the item being edited, it can
be done with the ‘widget-put’ and ‘widget-get’ functions.  The property
names, as shown, are keywords, so they must begin with a ‘:’.

5 Setting Up the Buffer
***********************

To show the widgets in a buffer, you have to create them.  Widget
creation is actually a two-step process: conversion and creation per se.
With simple projects, usually the conversion step isn’t really
important, and you only care about widget creation, so feel free to skip
the conversion description until you really need to know it.

   Widget conversion is the process that involves taking a widget
specification and transforming it into a “widget” object, suitable to be
created, queried and manipulated with other widget functions.  Widget
creation is the process that takes a widget object and actually inserts
it in the buffer.

   The simplest function to create a widget is ‘widget-create’, which
gets a widget specification and returns a widget object.

 -- Function: widget-create type [ keyword argument ]... args
     Create and return a widget of type TYPE, converting it.

     TYPE is a symbol that specifies a widget type.  KEYWORD may be one
     of the properties supported by the widget type, and ARGUMENT
     specify the value for that property.  These keyword arguments can
     be used to overwrite the keyword arguments that are part of TYPE by
     default, as well as to provide other properties not present in TYPE
     by default.  ARGS holds additional information for the creation of
     TYPE and each widget type is responsible for handling that
     information in a specific way.

     The syntax for the TYPE argument is described in *note Widget
     Gallery::, and in more detail in every widget where it’s relevant.

   There are other functions for creating widgets, useful when you work
with composite widgets.  That is, widgets that are part of other
widgets.

 -- Function: widget-create-child-and-convert parent type &rest args
     Create a widget of type TYPE as a child of PARENT.

     Before creating it, converts TYPE using the keyword arguments
     provided in ARGS.  Adds the ‘:indent’ property, unless it is
     already present, and sets it to the sum of the values of: ‘:indent’
     and ‘:offset’ from PARENT and ‘:extra-offset’ from TYPE.

     Returns a widget object, with the property ‘:parent’ set to PARENT.

 -- Function: widget-create-child parent type
     Create a widget of type TYPE as a child of PARENT.

     This function is like ‘widget-create-child-and-convert’ but it
     doesn’t convert TYPE, so it expects an already converted widget.

 -- Function: widget-create-child-value parent type value
     Create a widget of type TYPE as a child of PARENT with value VALUE.

     This function is like ‘widget-create-child’, but it lets you
     specify a value for the widget.

     Converts VALUE to the internal format, as specified by TYPE, and
     stores it into the ‘:value’ property of TYPE.  That means, VALUE
     should be in the external format, as specified by TYPE.

   All these creating functions described here use the function stored
in the ‘:create’ property.  So, to modify the creation logic for a
widget, you can provide a different ‘:create’ function.

   When you’re done creating widgets and you’re ready for the user to
interact with the buffer, use the function ‘widget-setup’.

 -- Function: widget-setup
     Setup the current buffer, so that editable widgets can be edited.

     This should be called after creating all the widgets and before
     allowing the user to edit them.

   As mentioned, all these functions return a widget object.  That
widget object can be queried and manipulated with widget functions that
take widgets as arguments, until deleting it with the widgets functions
available to delete widgets.  Even if you don’t save the returned widget
object, you still can interact programmatically with the widget.  *Note
Working with Widgets::.

 -- Function: widget-delete widget
     Delete the widget WIDGET and remove it from the buffer.

 -- Function: widget-children-value-delete widget
     Delete all children and buttons in widget WIDGET.

     This function does not delete WIDGET itself, only the widgets
     stored in the ‘:children’ and ‘:buttons’ properties.  It also sets
     those properties to ‘nil’.

   As with the creation mechanism, the function stored in ‘:delete’
controls the deletion mechanism for a widget.

   Additionally, the library provides a way to make a copy of a widget.

 -- Function: widget-copy widget
     Makes a copy of widget WIDGET and returns it.

     It uses the function stored in the ‘:copy’ property of WIDGET and
     returns the widget that that function returns.

   As discussed, there is a conversion step when creating a widget.  To
do the conversion without actually creating the widget, you can use the
‘widget-convert’ function.

 -- Function: widget-convert type &rest args
     Convert TYPE to a widget object, using keyword arguments ARGS.

     Returns a widget object, suitable for creation.  It calls the
     function stored in the ‘:convert-widget’ property, after putting
     into the ‘:args’ property the arguments that the widget in question
     needs.  If TYPE has a ‘:value’ property, either originally or after
     doing the conversion, this function converts the value stored in
     ‘:value’ to the internal format, and stores it into ‘:value’.

   Apart from only creating widgets in the buffer, It’s useful to have
plain text.  For inserting text, the recommended way is with the
‘widget-insert’ function.

 -- Function: widget-insert &rest args
     Insert ARGS, either strings or characters, at point.

     Uses ‘insert’ to perform the insertion, passing ARGS as argument.
     *Note (elisp)Insertion::, for more information about ARGS.

     The resulting text will be read-only.

6 Working with Widgets
**********************

This section covers the more important functions needed to query and
manipulate widgets in a generic way.  Widgets may have additional
functions for interacting with them, those are described in the
description for each widget.  *Note Widget Gallery::.

 -- Function: widgetp widget
     Non-‘nil’ if WIDGET is a widget.

 -- Function: widget-type widget
     Return the type of widget WIDGET, a symbol.

     This function is useful to find out which kind of widget WIDGET
     represents, i.e., the name of the widget type when the widget was
     created.

 -- Function: widget-member widget property
     Non-‘nil’ if widget WIDGET has a value (even ‘nil’) for property
     PROPERTY.

 -- Function: widget-get widget property
     For widget WIDGET, return the value of the property PROPERTY.

     PROPERTY should be a keyword, and the value is what was last set by
     ‘widget-put’ for PROPERTY.

 -- Function: widget-put widget property value
     For widget WIDGET, set the property PROPERTY to VALUE.  PROPERTY
     should be a keyword, while VALUE can be anything.

 -- Function: widget-at &optional pos
     Return the widget at position POS, or at point if POS is ‘nil’.

 -- Function: widget-field-at pos
     Return the widget field at position POS, or ‘nil’ if there is none.

 -- Function: widget-apply widget property &rest args
     Apply the function stored in PROPERTY to WIDGET, passing ARGS as
     additional arguments to the function.

     Returns the result of that function call.

 -- Function: widget-value widget
     Return the current value contained in WIDGET.

     Note that the value returned by this function might differ from
     what’s stored in the ‘:value’ property of WIDGET.  This is because
     this function extracts the current value of WIDGET from the buffer,
     taking editions into account.

     The value returned is in the external format, after getting it with
     the ‘:value-get’ function.

     It is an error to call this function on an uninitialized widget.

 -- Function: widget-value-set widget value
     Set the value contained in WIDGET to VALUE.

     Converts VALUE to the internal format, and then sets it by applying
     the ‘:value-set’ function.

     It is an error to call this function with an invalid VALUE, that
     is, a value that WIDGET cannot represent.

 -- Function: widget-default-get widget
     Return the default external value of widget WIDGET.

     The default value is the one stored in ‘:value’ or the result of
     applying the ‘:default-get’ function to the arguments of WIDGET, as
     stored in ‘:args’.  A value of ‘nil’ is ignored by default, so in
     order for a widget to respect ‘nil’ as a value, it has to override
     the ‘:default-get’ function.

 -- Function: widget-type-default-get widget
     Convert the ‘:type’ attribute in WIDGET and return its default
     value.

 -- Function: widget-child-value-get widget
     Return the value of the first member of ‘:children’ in WIDGET.

 -- Function: widget-child-value-inline widget
     Return the inline value of the first member of ‘:children’ in
     WIDGET.

     The inline value is whatever the function stored in ‘:value-inline’
     returns.

 -- Function: widget-type-value-create widget
     Create a child widget for WIDGET, of type stored in ‘:type’.

     Creates the child widget taking the value from the ‘:value’
     property and stores the newly created widget in the ‘:children’
     property of WIDGET.

     The value stored in ‘:type’ should be an unconverted widget type.

 -- Function: widget-value-convert-widget widget
     Initializes the ‘:value’ property of WIDGET from ‘:args’.

     Sets ‘:args’ to ‘nil’ and returns the modified widget WIDGET.

 -- Function: widget-value-value-get widget
     Return the value stored in ‘:value’ for widget WIDGET.

     This is different to getting the current value for WIDGET with
     ‘widget-value’, since that function extracts the value from the
     buffer.

 -- Function: widget-apply-action widget &optional event
     Apply the function stored in ‘:action’ to WIDGET, in response to
     EVENT.

     It is an error to call this function with an inactive widget.

 -- Function: widget-parent-action widget &optional event
     Tell ‘:parent’ of WIDGET to handle EVENT.

     Optional EVENT is the event that triggered the action.

 -- Function: widget-child-validate widget
     Check that the first member of ‘:children’ in WIDGET is valid.

     To be valid means that the widget value passes the checks that the
     function stored in ‘:validate’ makes.

 -- Function: widget-children-validate widget
     Check that all ‘:children’ in WIDGET are valid.

     Returns ‘nil’ on success, or the first child that isn’t valid.

 -- Function: widget-type-match widget value
     Return non-‘nil’ if VALUE matches the value for the ‘:type’ widget.

     As with the other type functions, the widget stored in ‘:type’
     should be an unconverted widget.

 -- Function: widget-types-copy widget
     Copy the ‘:args’ value in WIDGET and store them in ‘:args’.

     Makes the copies by calling ‘widget-copy’ on each element present
     in ‘:args’.  Returns the modified widget WIDGET.

 -- Function: widget-types-convert-widget widget
     Convert the ‘:args’ value in WIDGET and store them in ‘args’.

     Returns the modified widget WIDGET.

7 Widgets and the Buffer
************************

This chapter describes commands that are specific to buffers that
contain widgets.

 -- Const: widget-keymap
     Keymap containing useful bindings for buffers containing widgets.

     Binds <TAB> and ‘C-<TAB>’ to ‘widget-forward’ and
     ‘widget-backward’, respectively.  It also binds <RET> to
     ‘widget-button-press’ and ‘down-mouse-1’ and ‘down-mouse-2’ to
     ‘widget-button-click’.

   There’s also a keymap for events that the widget library doesn’t need
to handle.

 -- Variable: widget-global-map
     Keymap used by ‘widget-button-press’ and ‘widget-button-click’ when
     not on a button.  By default this is ‘global-map’.

   In addition to these two keymaps, each widget might define a keymap
of its own, active when events happen at that widget.

   The following navigation commands are available:

‘<TAB>’
      -- Command: widget-forward &optional count
          Move point COUNT buttons or editing fields forward.
‘M-<TAB>’
‘S-<TAB>’
      -- Command: widget-backward &optional count
          Move point COUNT buttons or editing fields backward.

   When editing an ‘editable-field’ widget, the following commands are
available:

‘<C-e>’
      -- Command: widget-end-of-line
          Move point to the end of field or end of line, whichever is
          first.

‘C-k’
      -- Command: widget-kill-line
          Kill to end of field or end of line, whichever is first.

‘M-TAB’
      -- Command: widget-complete
          Complete the content of the editable field at point.

‘C-m’
      -- Command: widget-field-activate
          Invoke the editable field at point.

   The following two are commands that can execute widget actions.
‘<RET>’
      -- Command: widget-button-press POS &optional EVENT
          Invoke the button at POS, defaulting to point.

          Invocation means to run the function stored in the ‘:action’
          property.

          If point is not located on a button, invoke the binding in
          ‘widget-global-map’ (by default the global map).

‘mouse-2’
      -- Command: widget-button-click EVENT
          Invoke the button at the location of the mouse pointer.

          If the mouse pointer is located in an editable text field,
          invoke the binding in ‘widget-global-map’ (by default the
          global map).

          In case the mouse-click is on a widget, calls the function
          stored in the ‘:mouse-down-action’ property.

8 Widget Gallery
****************

All widgets can be created from a type specification.  The general
syntax of a type specification is:

     NAME ::= (NAME [KEYWORD ARGUMENT]... ARGS)
          |   NAME

   Where NAME is a widget name, as defined with ‘define-widget’, KEYWORD
is the name of a property and ARGUMENT is the value for that property,
and ARGS are interpreted in a widget specific way.  *Note Defining New
Widgets::.

   The most basic widget in the Widget Library is the “default” widget.
It provides the basic behavior for all other widgets, and all its
properties are present by default in derived widgets.  You’re seldom (if
ever) going to effectively create a default widget, but here we describe
its properties and behavior, so that we can describe other widgets only
by mentioning the properties and behavior those other widgets
specialize.

 -- Widget: default
     Widget used as a base for other widgets.

     It provides most of the functionality that is referred to as “by
     default” in this text.  If you want to define a new widget from
     scratch, use the ‘default’ widget as its base.

   The following keyword arguments apply to all widgets:

‘:create’
     Function to create a widget from scratch.

     The function takes one argument, a widget type, and creates a
     widget of that type, inserts it in the buffer, and returns a widget
     object.

     By default, it inserts the widget at point, using the format
     provided in the ‘:format’ property.

‘:delete’
     Function to delete a widget.

     The function should take one argument, a widget, and should remove
     all traces of the widget from the buffer.

     The default value is:

      -- Function: widget-default-delete widget
          Remove WIDGET from the buffer.  Delete all ‘:children’ and
          ‘:buttons’ in WIDGET.

     In most cases you should not change this value, but instead use
     ‘:value-delete’ to make any additional cleanup.

‘:value’
     The initial value for widgets of this type.

     Typically, a widget represents its value in two formats: external
     and internal.  The external format is the value as the rest of
     Emacs sees it, and the internal format is a representation that the
     widget defines and uses in a widget specific way.

     Both formats might be the same for certain widgets and might differ
     for others, and there is no guarantee about which format the value
     stored in the ‘:value’ property has.  However, when creating a
     widget or defining a new one (*note Defining New Widgets::), the
     ‘:value’ should be in the external format.

‘:value-to-internal’
     Function to convert the value to the internal format.

     The function takes two arguments, a widget and an external value,
     and returns the internal value.  The function is called on the
     present ‘:value’ when the widget is created, and on any value set
     later with ‘widget-value-set’.

‘:value-to-external’
     Function to convert the value to the external format.

     The function takes two arguments, a widget and an internal value,
     and returns the value in the external format.

‘:value-create’
     Function to expand the ‘%v’ escape in the format string.

     It will be called with the widget as its argument and should insert
     a representation of the widget’s value in the buffer.

‘:value-delete’
     A function that should remove the representation of the widget’s
     value from the buffer.

     It will be called with the widget as its argument.  It doesn’t have
     to remove the text, but it should release markers and delete nested
     widgets if these are not listed in ‘:children’ or ‘:buttons’.

     By default, it’s a no-op.

‘:value-get’
     Function to extract the value of a widget, as it is displayed in
     the buffer.

‘:value-set’
     Function that takes a widget and a value as arguments, and
     recreates it.

     The value must already be in the internal format for widget.  By
     default, it deletes the widget with the ‘:delete’ function and
     creates it again with the ‘:create’ function.

‘:value-inline’
     Function that takes a widget and returns its value, inlined.

     Inlined means that if the widget is not inline (i.e., its ‘:inline’
     property is ‘nil’), the return value is wrapped in a list.

‘:default-get’
     Function that takes a widget and returns its default value.

     By default, it just returns the value stored in ‘:value’.

‘:format’
     This string will be inserted in the buffer when you create a
     widget.  The following ‘%’ escapes are available:

     ‘%[’
     ‘%]’
          The text inside will be marked as a button.

          By default, the text will be shown in ‘widget-button-face’,
          and surrounded by brackets.

     ‘%{’
     ‘%}’
          The text inside will be displayed with the face specified by
          ‘:sample-face’.

     ‘%v’
          This will be replaced with the buffer representation of the
          widget’s value.  What this is depends on the widget type.

     ‘%d’
          Insert the string specified by ‘:doc’ here.

     ‘%h’
          Like ‘%d’, with the following modifications: If the
          documentation string is more than one line, it will add a
          button which will toggle between showing only the first line,
          and showing the full text.  Furthermore, if there is no ‘:doc’
          property in the widget, it will instead examine the
          ‘:documentation-property’ property.  If it is a lambda
          expression, it will be called with the widget’s value as an
          argument, and the result will be used as the documentation
          text.

     ‘%t’
          Insert the string specified by ‘:tag’ here, or the ‘princ’
          representation of the value if there is no tag.

     ‘%%’
          Insert a literal ‘%’.

‘:button-face’
     Face used to highlight text inside %[ %] in the format.

‘:button-prefix’
‘:button-suffix’
     Strings used as prefix and suffix for widgets that are buttons.

     By default, the values are ‘widget-button-prefix’ and
     ‘widget-button-suffix’.

     Text around %[ %] in the format.

     These can be
     _nil_
          No text is inserted.

     _a string_
          The string is inserted literally.

     _a symbol_
          The value of the symbol is expanded according to this table.

‘:doc’
     The string inserted by the ‘%d’ escape in the format string.

‘:tag’
     The string inserted by the ‘%t’ escape in the format string.

‘:tag-glyph’
     Name of image to use instead of the string specified by ‘:tag’ on
     Emacsen that supports it.

‘:help-echo’
     Specifies how to display a message whenever you move to the widget
     with either ‘widget-forward’ or ‘widget-backward’ or move the mouse
     over it (using the standard ‘help-echo’ mechanism).

     The value is either a string to display, or a function of one
     argument, the widget.  If a function, it should return a string to
     display, or a form that evaluates to such a string.

‘:follow-link’
     Specifies how to interpret a <mouse-1> click on the widget.  *Note
     Defining Clickable Text: (elisp)Clickable Text.

‘:indent’
     An integer indicating the absolute number of spaces to indent
     children of this widget.  Its value might be ‘nil’ too, which
     corresponds to a value of 0.

     The default ‘:create’ functions and the functions that create the
     value per se use this property as a rudimentary layout mechanism
     for the widgets.

‘:offset’
     An integer indicating how many extra spaces to add to the widget’s
     grandchildren compared to this widget.

‘:extra-offset’
     An integer indicating how many extra spaces to add to the widget’s
     children compared to this widget.

‘:menu-tag’
     Tag used in the menu when the widget is used as an option in a
     ‘menu-choice’ widget.

‘:menu-tag-get’
     Function that takes a widget and returns the tag when the widget is
     used as an option in a ‘menu-choice’ widget.

     By default, the tag used will be either the ‘:menu-tag’ or ‘:tag’
     property if present, or the ‘princ’ representation of the ‘:value’
     property if not.

‘:match’
     Should be a function called with two arguments, the widget and an
     external value, and should return non-‘nil’ if the widget can
     represent the specified value.

‘:validate’
     A function which takes a widget as an argument, and returns ‘nil’
     if the widget’s current value is valid for the widget.

     Otherwise, it should return the widget containing the invalid data,
     and set that widget’s ‘:error’ property to a string explaining the
     error.

     By default, it always returns ‘nil’.

‘:tab-order’
     Specify the order in which widgets are traversed with
     ‘widget-forward’ or ‘widget-backward’.  This is only partially
     implemented.
       a. Widgets with tabbing order ‘-1’ are ignored.

       b. (Unimplemented) When on a widget with tabbing order N, go to
          the next widget in the buffer with tabbing order N+1 or ‘nil’,
          whichever comes first.

       c. When on a widget with no tabbing order specified, go to the
          next widget in the buffer with a positive tabbing order, or
          ‘nil’

‘:parent’
     The parent of a nested widget (e.g., a ‘menu-choice’ item or an
     element of a ‘editable-list’ widget).

‘:sibling-args’
     This keyword is only used for members of a ‘radio-button-choice’ or
     ‘checklist’.  The value should be a list of extra keyword
     arguments, which will be used when creating the ‘radio-button’ or
     ‘checkbox’ associated with this item.

‘:completions-function’
     Function that takes a widget and returns completion data for that
     widget, like ‘completion-at-point-functions’ would.  *Note
     (elisp)Completion::.  It’s used by ‘editable-field’ widgets to
     provide completions.

     By default, it looks into the property ‘:completions’, which should
     be a completion table.  If ‘:completions’ is ‘nil’, then it calls
     the function stored either in the ‘:complete’ or
     ‘:complete-function’ property.

‘:format-handler’
     Function to handle unknown ‘%’ escapes in the format string.

     It takes a widget and the character that follows the ‘%’ as
     arguments.  You can set this to allow your widget to handle
     non-standard escapes in your own specialized widgets.

     You should end up calling ‘widget-default-format-handler’ to handle
     unknown escape sequences, which will handle the ‘%h’ and any future
     escape sequences, as well as give an error for unknown escapes.

‘:button-face-get’
     Function to return the face used to fontify a widget button.

     Takes a widget and returns an appropriate face for the widget.  By
     default, it either returns the face stored in the ‘:button-face’
     property, or calls the ‘:button-face-get’ function from the parent
     of the widget, if it has one.

‘:mouse-face-get’
     Function to return the face used to fontify a widget when the mouse
     pointer hovers over it.

     Takes a widget and returns an appropriate face.  By default, it
     either returns the face stored in the ‘:mouse-face’ property, or
     calls the ‘:button-face-get’ function from the parent of the
     widget, if it has one.

‘:copy’
     Function to deep copy a widget type.

     It takes a shallow copy of the widget type as an argument (made by
     ‘copy-sequence’), and returns a deep copy.  The purpose of this is
     to avoid having different instances of combined widgets share
     nested attributes.

     Its value by default is ‘identity’.

‘:active’
     Function that takes a widget and returns ‘t’ if it is active.

     A widget might be effectively always active, if its
     ‘:always-active’ property is ‘t’.

     Widgets can be in two states: active, which means they are
     modifiable by the user, or inactive, which means they cannot be
     modified by the user.  You can query or set the state with the
     following code:

          ;; Examine if WIDGET is active or not.
          (if (widget-apply WIDGET :active)
              (message "Widget is active.")
            (message "Widget is inactive.")

          ;; Make WIDGET inactive.
          (widget-apply WIDGET :deactivate)

          ;; Make WIDGET active.
          (widget-apply WIDGET :activate)

     A widget is inactive if it, or any of its ancestors (found by
     following the ‘:parent’ link), have been deactivated.  To make sure
     a widget is really active, you must therefore activate both it and
     all its ancestors.

          (while widget
            (widget-apply widget :activate)
            (setq widget (widget-get widget :parent)))

     You can check if a widget has been made inactive by examining the
     value of the ‘:inactive’ keyword.  If this is non-‘nil’, the widget
     itself has been deactivated.  This is different from using the
     ‘:active’ keyword, in that the latter tells you if the widget *or*
     any of its ancestors have been deactivated.  Do not attempt to set
     the ‘:inactive’ keyword directly.  Use the ‘:activate’
     ‘:deactivate’ functions instead.

‘:activate’
     Function that takes a widget and makes it active for user
     modifications.

‘:deactivate’
     Function that takes a widget and makes it inactive for user
     modifications.

‘:action’
     Function that takes a widget and optionally an event, and handles a
     user initiated event.

     By default, uses the ‘:notify’ function to notify the widget’s
     parent about the event.

‘:mouse-down-action’
     Function that takes a widget and optionally an event, and handles a
     mouse click on the widget.

     By default, it does nothing.

‘:notify’
     A function called each time the widget or a nested widget is
     changed.

     The function is called with two or three arguments.  The first
     argument is the widget itself, the second argument is the widget
     that was changed, and the third argument is the event leading to
     the change, if any.

     By default, it passes the notification to the widget’s parent.

‘:prompt-value’
     Function to prompt for a value in the minibuffer.

     The function should take four arguments, a widget, a prompt (a
     string), a value and a boolean, and should return a value for the
     widget, entered by the user.

     The prompt is the prompt to use.  The value is the default value to
     use, unless the fourtha argument is non-‘nil’, in which case there
     is no default value.

     The function should read the value using the method most natural
     for this widget, and does not have to check that it matches.

8.1 Basic Types
===============

8.1.1 The ‘item’ Widget
-----------------------

Syntax:

     TYPE ::= (item [KEYWORD ARGUMENT]... VALUE)

   A useful widget that holds a constant value, and can be included in
other widgets.  Its super is the ‘default’ widget.

   As can be seen in the syntax, the ‘item’ widget is one of the widget
that handles the ARGS argument to ‘widget-create’ in a specific way.  If
present, VALUE is used to initialize the ‘:value’ property.  When
created, it inserts the value as a string in the buffer.

   By default, it has the following properties:

‘:convert-widget’
     The function that allows it to handle VALUE.

‘:value-create’
     Prints the representation of ‘:value’ in the buffer.

‘:value-get’
     Returns the value stored in ‘:value’.

‘:match’
     A value matches the ‘item’ widget if it’s ‘equal’ to its ‘:value’.

‘:match-inline’
     Inline values match the ‘item’ widget if ‘:value’ is a sublist of
     values.

‘:action’
     The ‘item’ widget notifies itself of an event.

‘:format’
     By default, the ‘item’ widget inserts its tag in the buffer.

8.1.2 The ‘link’ Widget
-----------------------

Syntax:

     TYPE ::= (link [KEYWORD ARGUMENT]...  [ VALUE ])

   A widget to represent an embedded link.  Its super is the ‘item’
widget.

   The VALUE, if present, is used to initialize the ‘:value’ property.
The value should be a string, which will be inserted in the buffer.

   By default, it has the following properties:

‘:button-prefix’
     The value of ‘widget-link-prefix’.

‘:button-suffix’
     The value of ‘widget-link-suffix’.

‘:keymap’
     A custom keymap for the link widget, so that it can respond to
     mouse clicks.

‘:follow-link’
     This property allows the link to respect the value of
     ‘mouse-1-click-follows-link’.  *Note (elisp)Clickable Text::.

‘:format’
     Buttonizes the link, to make it clickable.

     If you override this property, you should make sure to provide the
     ‘%[’ and ‘%]’ escape sequences, so that the link is clickable.

   By default the link will be shown in brackets.

8.1.3 The ‘url-link’ Widget
---------------------------

Syntax:

     TYPE ::= (url-link [KEYWORD ARGUMENT]...  URL)

   A widget to represent a link to a web page.  Its super is the ‘link’
widget.

   It overrides the ‘:action’ property to open up the URL specified.

8.1.4 The ‘info-link’ Widget
----------------------------

Syntax:

     TYPE ::= (info-link [KEYWORD ARGUMENT]...  ADDRESS)

   A widget to represent a link to an info file.  Its super is the
‘link’ widget.

   It overrides the ‘:action’ property, to a function to start the
built-in Info reader on ADDRESS, when invoked.

8.1.5 The ‘function-link’ Widget
--------------------------------

Syntax:

     TYPE ::= (function-link [KEYWORD ARGUMENT]...  FUNCTION)

   A widget to represent a link to an Emacs function.  Its super is the
‘link’ widget.

   It overrides the ‘:action’ property, to a function to describe
FUNCTION.

8.1.6 The ‘variable-link’ Widget
--------------------------------

Syntax:

     TYPE ::= (variable-link [KEYWORD ARGUMENT]...  VAR)

   A widget to represent a link to an Emacs variable.  Its super is the
‘link’ widget.

   It overrides the ‘:action’ property, to a function to describe VAR.

8.1.7 The ‘face-link’ Widget
----------------------------

Syntax:

     TYPE ::= (face-link [KEYWORD ARGUMENT]...  FACE)

   A widget to represent a link to an Emacs face.  Its super is the
‘link’ widget.

   It overrides the ‘:action’ property, to a function to describe FACE.

8.1.8 The ‘file-link’ Widget
----------------------------

Syntax:

     TYPE ::= (file-link [KEYWORD ARGUMENT]...  FILE)

   A widget to represent a link to a file.  Its super is the ‘link’
widget.

   It overrides the ‘:action’ property, to a function to find the file
FILE.

8.1.9 The ‘emacs-library-link’ Widget
-------------------------------------

Syntax:

     TYPE ::= (emacs-library-link [KEYWORD ARGUMENT]...  FILE)

   A widget to represent a link to an Emacs Lisp file.  Its super is the
‘link’ widget.

   It overrides the ‘:action’ property, to a function to find the file
FILE.

8.1.10 The ‘emacs-commentary-link’ Widget
-----------------------------------------

Syntax:

     TYPE ::= (emacs-commentary-link [KEYWORD ARGUMENT]...  FILE)

   A widget to represent a link to the Comment section of an Emacs Lisp
file.  Its super is the ‘link’ widget.

   It overrides the ‘:action’ property, to a function to find the file
FILE and put point in the Comment section.

8.1.11 The ‘push-button’ Widget
-------------------------------

Syntax:

     TYPE ::= (push-button [KEYWORD ARGUMENT]...  [ VALUE ])

   A widget that acts as a pushable button.  Its super is the ‘item’
widget.

   The VALUE, if present, is used to initialize the ‘:value’ property.
The value should be a string, which will be inserted in the buffer.

   By default, it has the following properties:
‘:button-prefix’
     The empty string.

‘:button-suffix’
     The empty string.

‘:value-create’
     Inserts a representation of the “on” and “off” states for the push
     button.

     The representation might be an image, stored in the ‘:tag-glyph’
     property, or text.  If it is text, it might be the value of the
     ‘:tag’ property, or the ‘:value’ of the widget, surrounded with
     ‘widget-push-button-prefix’ and ‘widget-push-button-suffix’.  *Note
     Customization::.

‘:format’
     Buttonizes the widget, to make it clickable.

8.1.12 The ‘editable-field’ Widget
----------------------------------

Syntax:

     TYPE ::= (editable-field [KEYWORD ARGUMENT]... [ VALUE ])

   A widget that can be edited by the user.  Its super is the ‘default’
widget.

   The VALUE, if present, is used to initialize the ‘:value’ property.
The value should be a string, which will be inserted in the field.  If
not present, ‘:value’ is the empty string.

   *Warning:* In an ‘editable-field’ widget, the editable field must not
be adjacent to another widget—that won’t work.  You must put some text
in between.  Either make this text part of the ‘editable-field’ widget
itself, or insert it with ‘widget-insert’.

   This widget either overrides or adds the following properties:

‘:convert-widget’
     Just like the ‘item’ widget, this function allows it to initialize
     ‘:value’ from VALUE.

‘:keymap’
     Keymap used in the editable field.

     The default value is ‘widget-field-keymap’, which allows the user
     to use all the normal editing commands, even if the buffer’s major
     mode suppresses some of them.  Pressing <RET> invokes the function
     specified by ‘:action’.

‘:format’
     By default, it specifies to insert only the widget’s value.

     *Warning:* In an ‘editable-field’ widget, the ‘%v’ escape must be
     preceded by some other text in the ‘:format’ string (if specified).

‘:size’
     The width of the editable field.

     By default the field will reach to the end of the line.

‘:value-face’
     Face used for highlighting the editable field.

     Default is ‘widget-field-face’, *note User Interface::.

‘:secret’
     Character used to display the value.

     You can set this to, e.g., ‘?*’ if the field contains a password or
     other secret information.  By default, this is ‘nil’, and the value
     is not secret.

‘:valid-regexp’
     By default the ‘:validate’ function will match the content of the
     field with the value of this attribute.

     The default value is ‘""’ which matches everything.

‘:validate’
     Returns ‘nil’ if the current value of the widget matches the
     ‘:valid-regexp’ value.

‘:prompt-internal’
     A function to read a value for widget, used by the ‘:prompt-value’
     function.

‘:prompt-history’
     A variable that holds the history of field minibuffer edits.

‘:prompt-value’
     A function that uses the ‘:prompt-internal’ function and the
     ‘:prompt-history’ value to prompt for a string, and retun the user
     response in the external format.

‘:action’
     When invoked, moves point to the next field.

‘:value-create’
     Function that takes care of creating the widget, respecting its
     ‘:size’ and ‘:value’.

‘:value-set’
     Function to use to modify programatically the current value of the
     widget.

‘:value-delete’
     Function that removes the widget so it cannot be edited anymore.

‘:value-get’
     Function to return the current text in the widget.

     It takes an optional argument, NO-TRUNCATE.  If NO-TRUNCATE is nil,
     truncates trailing spaces.

‘:match’
     Function that makes the widget match any string value.

8.1.13 The ‘text’ Widget
------------------------

Syntax:

     TYPE ::= (text [KEYWORD ARGUMENT]... [ VALUE ])

   A widget just like the ‘editable-field’ widget, but intended for
multiline text fields.  Its super is the ‘editable-field’ widget.

   It overrides the following properties:

‘:format’
     By default, prints a tag and the value.

‘:keymap’
     The default is ‘widget-text-keymap’, which does not rebind the
     <RET> key.

8.1.14 The ‘menu-choice’ Widget
-------------------------------

Syntax:

     TYPE ::= (menu-choice [KEYWORD ARGUMENT]... TYPE ... )

   A widget to represent a menu of options.  Its super is the ‘default’
widget.

   The TYPE argument represents each possible choice.  The widget’s
value will be that of the chosen TYPE argument.

   It either overrides or adds the following properties:

‘:convert-widget’
     A function that takes care of converting each possible choice.

‘:copy’
     A function to copy each possible choice.

‘:format’
     By default, buttonize the tag and show the value.

‘:void’
     Widget type used as a fallback when the value does not match any of
     the specified TYPE arguments.

     By default this is an ‘item’ widget.

‘:case-fold’
     If ‘nil’ don’t ignore case when prompting for a choice through the
     minibuffer.

     By default, its value is ‘t’.

‘:children’
     A list whose CAR is the widget representing the currently chosen
     type in the buffer.

‘:choice’
     The current chosen type.

‘:args’
     The list of types.

‘:value-create’
     The function that inserts the current value for the widget.

     It inserts the first choice that matches, as with the ‘:match’
     function, the value of the widget.

‘:value-get’
     Returns the value of the first child for the widget (see the
     description for ‘:children’ above).

‘:value-inline’
     Returns the inline value of the first child for the widget.

‘:default-get’
     The default value for this widget is the default value for the
     first choice, in case ‘:value’ is missing.

     This means that if you want a specific default value for the
     ‘menu-choice’ widget, you should either pass a ‘:value’ property
     when creating it, or arrange the choices so that the first one can
     hold your desired default value.

‘:mouse-down-action’
     A function that takes care of showing a menu, if possible and
     desired.

‘:action’
     A function that takes care of getting a new choice for the widget.

     Depending on the number of choices available, it may show a menu or
     just toggle the choices, or even do nothing at all.

     After getting the choice, it recreates the widget and notifies it.

‘:validate’
     Returns ‘nil’ if the widget’s value is a valid choice.

‘:match’
     This widget will match any value matching at least one of the
     specified TYPE arguments.

‘:match-inline’
     A function that returns non-‘nil’ if the values match the widget,
     taking into account the ‘:inline’ property.

8.1.15 The ‘radio-button-choice’ Widget
---------------------------------------

Syntax:

     TYPE ::= (radio-button-choice [KEYWORD ARGUMENT]...  TYPE ... )

   A widget to represent a choice from multiple options.  Its super is
the ‘default’ widget.

   The component TYPES specify the choices, with one radio button for
each.  The widget’s value will be that of the chosen TYPE argument.

   It overrides the following properties:

‘:convert-widget’
     As other composite widgets, a function that takes care of
     converting each available choice.

‘:copy’
     A function to copy each available choice.

‘:action’
     A function that checks if any radio button was pressed and
     activates the pressed one, possibly deactivating an old one.  Then,
     it notifies itself.

‘:entry-format’
     This string will be inserted for each entry in the list.  The
     following ‘%’ escapes are available:
     ‘%v’
          Replace with the buffer representation of the TYPE widget.
     ‘%b’
          Replace with the radio button.
     ‘%%’
          Insert a literal ‘%’.

‘:format’
     By default, it inserts its value.

‘:button-args’
     A list of keywords to pass to the radio buttons.  Useful for
     setting, e.g., the ‘:help-echo’ for each button.

‘:buttons’
     The widgets representing the radio buttons.

‘:children’
     The widgets representing each type.

‘:choice’
     The current chosen type.

‘:args’
     The list of types.

‘:value-create’
     A function to insert all available choices.

‘:value-get’
     Returns the value for the chosen widget.

‘:value-set’
     A function to set the value to one of its available options.

‘:value-inline’
     A function that returns the inline value of the child widget.

‘:offset’
     By default, this widget has an offset of 4.

‘:validate’
     The widget validates if the current value is valid for one of its
     children.

‘:match’
     This widget matches any value that matches at least one of the
     specified TYPE arguments.

‘:match-inline’
     Like the ‘:match’ function, but taking into account inline values.

   You can add extra radio button items to a ‘radio-button-choice’
widget after it has been created with the function
‘widget-radio-add-item’.

 -- Function: widget-radio-add-item widget type
     Add to ‘radio-button-choice’ widget WIDGET a new radio button item
     of type TYPE.

   Please note that such items added after the ‘radio-button-choice’
widget has been created will *not* be properly destructed when you call
‘widget-delete’.

8.1.16 The ‘choice-item’ Widget
-------------------------------

Syntax:

     ITEM ::= (choice-item [KEYWORD ARGUMENT]... VALUE)

   A widget to represent a choice in a ‘menu-choice’ widget.  Its super
is the ‘item’ widget.

   The VALUE, if present, is used to initialize the ‘:value’ property.

   It overrides the following properties:

‘:action’
     Activating the button of a ‘choice-item’ is equivalent to
     activating the parent widget.

‘:format’
     By default, it buttonizes the tag (i.e., its value) and adds a
     newline character at the end of the widget.

8.1.17 The ‘toggle’ Widget
--------------------------

Syntax:

     TYPE ::= (toggle [KEYWORD ARGUMENT]...)

   A widget that can toggle between two states.  Its super is the ‘item’
widget.

   The widget has two possible states, ‘on’ and ‘off’, which correspond
to a ‘t’ or ‘nil’ value, respectively.

   It either overrides or adds the following properties:

‘:format’
     By default, it buttonizes the value and adds a newline at the end
     of the widget.

‘:on’
     A string representing the ‘on’ state.  By default the string ‘on’.

‘:off’
     A string representing the ‘off’ state.  By default the string
     ‘off’.

‘:on-glyph’
     Name of a glyph to be used instead of the ‘:on’ text string, on
     emacsen that supports this.

‘:off-glyph’
     Name of a glyph to be used instead of the ‘:off’ text string, on
     emacsen that supports this.

‘:value-create’
     A function for creating the widget’s value, according to its ‘:on’
     or ‘:off’ state.

‘:action’
     Function to toggle the state of the widget.  After toggling, it
     notifies itself.

‘:match’
     This widget matches anything.

8.1.18 The ‘radio-button-toggle’ Widget
---------------------------------------

Syntax:

     TYPE ::= (radio-button-toggle [KEYWORD ARGUMENT]...)

   A toggle to use in the ‘radio’ widget.

   It overrides the following properties:

‘:button-prefix’
     The empty string.

‘:button-suffix’
     The empty string.

‘:on’
     The string “(*)”, to represent the ‘on’ state.

‘:off’
     The string “( )”, to represent the ‘off’ state.

‘:on-glyph’
     The name of an image to represent the ‘on’ state.

‘:off-glpyh’
     The name of an image to represent the ‘off’ state.

‘:format’
     By default, it buttonizes its value.

‘:notify’
     A function to notify its parent.

8.1.19 The ‘checkbox’ Widget
----------------------------

Syntax:

     TYPE ::= (checkbox [KEYWORD ARGUMENT]...)

   A widget to represent a toggle widget, with a checkbox.  Its super is
the ‘toggle’ widget.

   This widget has two possible states, ‘selected’ and ‘unselected’,
which corresponds to a ‘t’ or ‘nil’ value, respectively.

   It either overrides or adds the following properties:

‘:button-prefix’
     The empty string.

‘:button-suffix’
     The empty string.

‘:format’
     By default, buttonizes the value.

‘:on’
     By default, the string “[X]”.

‘:off’
     By default, the string “[ ]”.

‘:on-glyph’
     The name of the image to use when the state is ‘on’.

‘:off-glyph’
     The name of the image to use when the state is ‘off’.

‘:action’
     A function that toggles the checkbox, notifies the parents and in
     the ‘on’ state, activates its siblings.

8.1.20 The ‘checklist’ Widget
-----------------------------

Syntax:

     TYPE ::= (checklist [KEYWORD ARGUMENT]...  TYPE ... )

   A widget to represent a multiplice choice.  Its super is the
‘default’ widget.

   The TYPE arguments represent each checklist item.  The widget’s value
will be a list containing the values of all checked TYPE arguments.

   It either overrides or adds the following properties:

‘:convert-widget’
     As other composite widgets, a function that takes care of
     converting each checklist item.

‘:copy’
     A function to copy each checklist item.

‘:format’
     By default, it inserts its value.

‘:entry-format’
     This string will be inserted for each entry in the list.  The
     following ‘%’ escapes are available:
     ‘%v’
          Replaced with the buffer representation of the TYPE widget.
     ‘%b’
          Replace with the checkbox.
     ‘%%’
          Insert a literal ‘%’.

‘:button-args’
     A list of keywords to pass to the checkboxes.  Useful for setting,
     e.g., the ‘:help-echo’ for each checkbox.

‘:buttons’
     The widgets representing the checkboxes.

‘:children’
     The widgets representing each type.

‘:args’
     The list of types.

‘:value-create’
     The function that takes care of inserting all values.

‘:value-get’
     A function that returns all values of selected items.

‘:validate’
     A function that ensures all selected children are valid.

‘:match’
     The checklist widget will match a list whose elements all match at
     least one of the specified TYPE arguments.

‘:match-inline’
     Like the ‘:match’ function, but taking into account the ‘:inline’
     property.

‘:greedy’
     Usually a checklist will only match if the items are in the exact
     sequence given in the specification.  By setting ‘:greedy’ to
     non-‘nil’, it will allow the items to come in any sequence.
     However, if you extract the value they will be in the sequence
     given in the checklist, i.e., the original sequence is forgotten.

8.1.21 The ‘editable-list’ Widget
---------------------------------

Syntax:

     TYPE ::= (editable-list [KEYWORD ARGUMENT]... TYPE)

   A widget that can hold a variable list of widgets of the same type,
represented by TYPE.  Its super is the ‘default’ widget.

   It either overrides or adds the following properties:

‘:convert-widget’
     As other composite widgets, a function that takes care of
     converting each type in TYPE.

‘:copy’
     A function to copy the types given in TYPE.

‘:entry-format’
     This string will be inserted for each entry in the list.  The
     following ‘%’ escapes are available:
     ‘%v’
          This will be replaced with the buffer representation of the
          TYPE widget.
     ‘%i’
          Insert the [INS] button, a widget of type ‘insert-button’.
     ‘%d’
          Insert the [DEL] button, a widget of type ‘delete-button’.
     ‘%%’
          Insert a literal ‘%’.

‘:insert-button-args’
     A list of keyword arguments to pass to the insert buttons.

‘:delete-button-args’
     A list of keyword arguments to pass to the delete buttons.

‘:append-button-args’
     A list of keyword arguments to pass to the trailing insert button.

‘:buttons’
     The widgets representing the insert and delete buttons.

‘:format’
     By default, insert its value and at the and adds an insert button.

     This is useful so that new elements can be added to the list upon
     user request.

‘:format-handler’
     A function that recognize the escape for inserting an insert
     button.

‘:offset’
     By default, this widget has an offset of 12.

‘:children’
     The widgets representing the elements of the list.

‘:args’
     List whose CAR is the type of the list elements.

‘:insert-before’
     Function to insert a new widget as a child of the ‘editable-list’
     widget.

     This function inserts a recently deleted child, if there is one.
     That is useful, so that the user can move elements in a list
     easily.  If there is not a recently deleted child, it inserts a
     child with its default value.

‘:delete-at’
     Function to delete a child from the widget, and store it into the
     ‘:last-deleted’ list, so that it can be reinserted when the
     ‘:insert-before’ function executes.

‘:value-create’
     The function that takes care of inserting all values.

‘:value-get’
     Function that returns a list with the value of the child widgets.

‘:validate’
     This widget validates if all children validate.

‘:match’
     To match, the value must be a list and all the list members must
     match the specified TYPE.

‘:match-inline’
     Like the ‘:match’ function, but taking into account inline values
     and widgets.

8.1.22 The ‘group’ Widget
-------------------------

Syntax:

     TYPE ::= (group [KEYWORD ARGUMENT]... TYPE...)

   A widget to group other widgets.  Its super is the ‘default’ widget.

   Its value is a list, with one member for each TYPE.

   It overrides the following properties:

‘:convert-widget’
     As other composite widgets, a function that takes care of
     converting each widget in TYPE.

‘:copy’
     A function to copy the types given in TYPE.

‘:format’
     By default, displays a newline character and its value.

‘:value-create’
     A function to create each of its components.

‘:value-get’
     The same function used by the ‘editable-list’ widget.

‘:default-get’
     A function that returns a list whose members are the default values
     of each widget it groups.

‘:validate’
     This widget validates if all of its children validate.

‘:match’
     This widget matches a value that matches each of its components.

‘:match-inline’
     As ‘:match’, but taking into account widgets and values that are
     inline.

8.1.23 The ‘documentation-string’ Widget
----------------------------------------

Syntax:

     TYPE ::= (documentation-string [KEYWORD ARGUMENT]... VALUE)

   A widget to represent a documentation string.  Its super is the
‘item’ widget.

   It either overrides or adds the following properties:

‘:format’
     By default, insert its value.

‘:value-create’
     Function to insert a documentation string, possibly hiding part of
     the documentation if its large.

     To show or hide the rest of the documentation, uses a ‘visibility’
     widget.

‘:action’
     Function to toggle showing the documentation upon an event.

‘:visibility-widget’
     A symbol, the type of the widget to use for the visibility widget.

     This is, by default, the symbol ‘visibility’.

8.2 Sexp Types
==============

A number of widgets for editing “s-expressions” (Lisp types), sexp for
short, are also available.  These basically fall in several categories
described in this section.

8.2.1 The Constant Widgets
--------------------------

The ‘const’ widget can contain any Lisp expression, but the user is
prohibited from editing it, which is mainly useful as a component of one
of the composite widgets.

   The syntax for the ‘const’ widget is:

     TYPE ::= (const [KEYWORD ARGUMENT]...  [ VALUE ])

   Its super is the ‘item’ widget.  The VALUE, if present, is used to
initialize the ‘:value’ property and can be any s-expression.

 -- Widget: const
     This will display any valid s-expression in an immutable part of
     the buffer.

     It overrides the ‘:prompt-value’ function, to avoid prompting and
     just return the widget’s value.

   There are two variations of the ‘const’ widget, namely
‘variable-item’ and ‘function-item’.  These should contain a symbol with
a variable or function binding, respectively.  The major difference from
the ‘const’ widget is that they will allow the user to see the variable
or function documentation for the symbol.

   This is accomplished via using the ‘%h’ format escape, and adding an
appropiate ‘:documentation-property’ function for each widget.

 -- Widget: variable-item
     An immutable symbol that is bound as a variable.

 -- Widget: function-item
     An immutable symbol that is bound as a function.

8.2.2 Generic Sexp Widget
-------------------------

The ‘sexp’ widget can contain any Lisp expression, and allows the user
to edit it inline in the buffer.

   The syntax for the ‘sexp’ widget is:

     TYPE ::= (sexp [KEYWORD ARGUMENT]...  [ VALUE ])

 -- Widget: sexp
     This widget represents an editable field that’s useful to edit any
     valid s-expression.

     The ‘sexp’ widget takes the same keyword arguments as the
     ‘editable-field’ widget.  *Note editable-field::.

     Its default value is ‘nil’.

 -- Widget: restricted-sexp
     A widget to edit Lisp expressions restricted to certain values or
     types.  Its super is the ‘sexp’ widget.

     It works just like the sexp widget, but it overrides the ‘:match’
     function to match for certain values.  To use this widget, either
     you must define a ‘:match’ function or give a ‘:match-alternatives’
     property.  The ‘:match-alternatives’ property holds a list of
     predicate functions to call when checking if a given value matches
     the widget.  Each predicate function will be called with one
     argument, the value to be matched, and should return non-‘nil’ on
     success.

     As an example, the ‘integer’ widget overrides ‘:match-alternatives’
     to ‘(integerp)’.

8.2.3 Atomic Sexp Widgets
-------------------------

The atoms are s-expressions that do not consist of other s-expressions.
For example, a string, a file name, or a symbol are atoms, while a list
is a composite type.  You can edit the value of an atom with the widgets
described in this section.

   The syntax for all the atoms is:

     TYPE ::= (CONSTRUCT [KEYWORD ARGUMENT]...  [ VALUE ])

   The VALUE, if present, is used to initialize the ‘:value’ property
and must be an expression of the same type as the widget.  That is, for
example, the string widget can only be initialized with a string.

   All the atom widgets take the same keyword arguments as the
‘editable-field’ widget.  *Note editable-field::.

 -- Widget: string
     An editable field widget that can represent any Lisp string.

     It offers completion via the ispell library and the ‘:complete’
     property.

 -- Widget: regexp
     An editable field widget that can represent a regular expression.

     Overrides the ‘:match’ and the ‘:validate’ properties to check that
     the value is a valid regexp.

 -- Widget: character
     An editable field widget that can represent a character.

     The character widget represents some characters (like the newline
     character) in a special manner, to make it easier for the user to
     see what’s the content of the character field.

 -- Widget: file
     A widget for editing file names.

     Keywords:
     ‘:completions’
          Offers file name completion to the user.

     ‘:prompt-value’
          A function to read a file name from the minibuffer.

     ‘:must-match’
          If this is set to non-‘nil’, only existing file names are
          allowed when prompting for a value in the minibuffer.

     ‘:match’
          The widget matches if the value is a string, and the file
          whose name is that string is an existing file, or if
          ‘:must-match’ is ‘nil’.

     ‘:validate’
          The widget is valid if its value matches.

 -- Widget: directory
     A widget for editing directory names.

     Its super is the ‘file’ widget, and it overrides the ‘:completions’
     property, to offer completions only for directories.

 -- Widget: symbol
     A widget for editing a Lisp symbol.

     Its value by default is ‘nil’.

 -- Widget: function
     A widget for editing a lambda expression, or a function name,
     offering completion.  Its super is the ‘restricted-sexp’ widget.

 -- Widget: variable
     A widget for editing variable names, offering completion.  Its
     super is the ‘symbol’ widget.

 -- Widget: integer
     A widget for editing integers in an editable field.  Its super is
     the ‘restricted-sexp’ widget.

     It has a default ‘:value’ of 0.

 -- Widget: natnum
     A widget for editing non-negative integers.  Its super is the
     ‘restricted-sexp’ widget.

     It has a default ‘:value’ of 0.

 -- Widget: float
     A widget for editing a floating point number.  Its super is the
     ‘restricted-sexp’ widget.

     It has a default ‘:value’ of 0.0.

 -- Widget: number
     A widget for editing a number, either floating point or integer.
     Its super is the ‘restricted-sexp’ widget.

     It has a default ‘:value’ of 0.0.

 -- Widget: boolean
     A widget for editing a boolean value.  Its super is the ‘toggle’
     widget.

     Its value may be ‘nil’, meaning false, or non-‘nil’, meaning true.

 -- Widget: color
     A widget to edit a color name.

     In addition, shows a sample that shows the selected color, if any.

 -- Widget: other
     A widget useful as the last item in a ‘choice’ widget, since it
     matches any value.

     Its super is the ‘sexp’ widget, and its ‘:value’ is ‘other’, by
     default.

 -- Widget: coding-system
     A widget that can represent a coding system name, offering
     completions.  *Note (elisp)Coding Systems::.  Its super is the
     ‘symbol’ widget.

     It has a default value of ‘undecided’.

 -- Widget: key
     A widget to represent a key sequence.

     It uses a special keymap as the ‘:keymap’.

8.2.4 Composite Sexp Widgets
----------------------------

The syntax for the composite widget construct is:

     TYPE ::= (CONSTRUCT [KEYWORD ARGUMENT]...  COMPONENT...)

where each COMPONENT must be a widget type.  Each component widget will
be displayed in the buffer, and will be editable by the user.

 -- Widget: cons
     A widget to edit cons-cell values.  Its super is the ‘group’
     widget.

     The value of a ‘cons’ widget must be a cons-cell whose CAR and CDR
     have two specified types.  It uses this syntax:

          TYPE ::= (cons [KEYWORD ARGUMENT]...  CAR-TYPE CDR-TYPE)

 -- Widget: choice
     A widget to hold a value of one of a fixed set of types.  Its super
     is the ‘menu-choice’ widget.

     The widget’s syntax is as follows:

          TYPE ::= (choice [KEYWORD ARGUMENT]...  TYPE ... )

     The value of a ‘choice’ widget can be anything that matches any of
     the TYPES.

     This widget only displays the widget that corresponds to the
     current choice.

 -- Widget: radio
     A widget to hold a value of one of a fixed set of options.  Its
     super is the ‘radio-button-choice’ widget.

 -- Widget: list
     A widget to edit a list value.  Its super is the ‘group’ widget.

     The value of a ‘list’ widget must be a list whose element types
     match the specified component types:

          TYPE ::= (list [KEYWORD ARGUMENT]...  COMPONENT-TYPE...)

     Thus, for example, ‘(list string number)’ matches lists of two
     elements, the first being a string and the second being a number.

 -- Widget: vector
     A widget to edit a vector value.  Its super is the ‘group’ widget.

     The ‘vector’ widget is like the ‘list’ widget but matches vectors
     instead of lists.  Thus, for example, ‘(vector string number)’
     matches vectors of two elements, the first being a string and the
     second being a number.

   The above suffice for specifying fixed size lists and vectors.  To
get variable length lists and vectors, you can use a ‘choice’, ‘set’, or
‘repeat’ widget together with the ‘:inline’ keyword.  If any component
of a composite widget has the ‘:inline’ keyword set, its value must be a
list which will then be spliced into the composite.  For example, to
specify a list whose first element must be a file name, and whose
remaining elements should either be the symbol ‘t’ or two strings (file
names), you can use the following widget specification:

     (list file
           (choice (const t)
                   (list :inline t
                         :value ("foo" "bar")
                         string string)))

   The value of a widget of this type will either have the form ‘(file
t)’ or ‘(file STRING STRING)’.

   This concept of ‘:inline’ may be hard to understand.  It was
certainly hard to implement, so instead of confusing you more by trying
to explain it here, I’ll just suggest you meditate over it for a while.

 -- Widget: set
     A widget to hold a list of members from a fixed set.  Its super is
     the ‘checklist’ widget.

     Its value is a list where the elements all belong to a given set.
     The order of elements of the list is not significant.

     Here’s the syntax:

          TYPE ::= (set [KEYWORD ARGUMENT]...  PERMITTED-ELEMENT ... )

     Use ‘const’ to specify each permitted element, like this: ‘(set
     (const a) (const b))’.

 -- Widget: repeat
     Specifies a list of any number of elements that fit a certain type.
     Its super is the ‘editable-list’ widget.

          TYPE ::= (repeat [KEYWORD ARGUMENT]...  TYPE)

 -- Widget: plist
     A widget to edit property lists.  Its super is the ‘list’ widget.

     It recognizes the following properties:

     ‘:options’
          A given set of recommended key-value values for the ‘plist’
          widget.  Each option shows up as a checklist item.

     ‘:key-type’
          The widget type to use for the plist keys.  By default, it
          uses the ‘symbol’ widget.

     ‘:value-type’
          The widget type to use for the plist values.  By default, it
          uses the ‘sexp’ widget.

 -- Widget: alist
     A widget to edit association lists.  Its super is the ‘list’
     widget.

     It recognizes the same properties that the ‘plist’ widget, with the
     difference that the ‘:key-type’ uses by default a ‘sexp’ widget.

   Most composite widgets do not allow for recursion.  That is, none of
the contained widgets may be of the same type that is currently being
defined.  To allow for this kind of widgets, there’s the ‘lazy’ widget.

 -- Widget: lazy
     A base widget for recursive data structures.  Its super is the
     ‘default’ widget.

     When instantiated, it contains a single inferior widget of the
     widget type specified in the ‘:type’ property.  Its value is the
     same as the value of this inferior widget.

9 Defining New Widgets
**********************

You can define specialized widgets with ‘define-widget’.  It allows you
to create a shorthand for more complex widgets, including specifying
component widgets and new default values for the keyword arguments.

 -- Function: define-widget name class doc &rest args
     Define a new widget type named NAME that derives from CLASS.

     NAME and CLASS should both be symbols, and CLASS should be one of
     the existing widget types.

     The third argument DOC is a documentation string for the widget.

     ARGS should be key-value pairs, overriding keyword values of CLASS,
     or adding new recognized keywords for NAME.

     Usually, you’ll want to derive from an existing widget type, like
     the ‘editable-field’ widget, or the ‘default’ widget, but it’s also
     possible to derive from nothing, by passing a value of ‘nil’ as
     CLASS.  Note that if you do this, you’re entirely responsible for
     defining a whole new default behavior for your widgets.

     After using this function, the following two calls will create
     identical widgets:

        •      (widget-create NAME)

        •      (apply widget-create CLASS ARGS)

   Using ‘define-widget’ just stores the definition of the widget type
in the ‘widget-type’ property of NAME, which is what ‘widget-create’
uses.

   If you only want to specify defaults for keywords with no complex
conversions, you can use ‘identity’ as your conversion function.

   When defining new widgets, the ‘:convert-widget’ property might be
useful:

‘:convert-widget’
     Function to convert a widget type before creating a widget of that
     type.

     It takes a widget type as an argument, and returns the converted
     widget type.  When a widget is created, this function is called for
     the widget type and all the widget’s parent types, most derived
     first.

     The predefined functions ‘widget-types-convert-widget’ and
     ‘widget-value-convert-widget’ can be used here.

10 Inspecting Widgets
*********************

There is a separate package to browse widgets, in ‘wid-browse.el’.  This
is intended to help programmers who want to examine the content of a
widget.  The browser shows the value of each keyword, but uses links for
certain keywords such as ‘:parent’, which avoids printing cyclic
structures.

 -- Command: widget-browse WIDGET
     Create a widget browser for WIDGET.

     When called interactively, prompt for WIDGET.

 -- Command: widget-browse-other-window WIDGET
     Create a widget browser for WIDGET and show it in another window.

     When called interactively, prompt for WIDGET.

 -- Command: widget-browse-at POS
     Create a widget browser for the widget at POS.

     When called interactively, use the position of point.

   In addition, there’s a function to describe the widget at point.

 -- Command: widget-describe &optional widget-or-pos
     Describe the widget at point.

     When called from Lisp, WIDGET-OR-POS might be the widget to
     describe or a buffer position where a widget is present.  If
     WIDGET-OR-POS is ‘nil’, the widget to describe is the widget at
     point.

     This command sets up a help buffer for providing information about
     the widget, mainly its ‘:action’ and ‘:mouse-down-action’
     functions, and provides links to describe it in more detail using
     the ‘widget-browse’ commands described above.

11 Widget Minor Mode
********************

There is a minor mode for manipulating widgets in major modes that don’t
provide any support for widgets themselves.  This is mostly intended to
be useful for programmers doing experiments.

 -- Command: widget-minor-mode
     Toggle minor mode for traversing widgets.  With arg, turn widget
     mode on if and only if arg is positive.

 -- Variable: widget-minor-mode-keymap
     Keymap used in ‘widget-minor-mode’.

12 Utilities
************

Here we describe some utility functions that don’t really have a place
earlier in this manual.

 -- Function: widget-prompt-value widget prompt [ value unbound ]
     Prompt for a value matching WIDGET, using PROMPT.  The current
     value is assumed to be VALUE, unless UNBOUND is non-‘nil’.

     Converts WIDGET before prompting, and for prompting it uses the
     ‘:prompt-value’ function.  This function returns the user “answer”,
     and it’s an error if that answer doesn’t match the widget, as with
     the ‘:match’ function.

     If the answer matches the widget, returns the answer.

 -- Function: widget-get-sibling widget
     Get the item which WIDGET should toggle.  This is only meaningful
     for radio buttons or checkboxes in a list.

 -- Function: widget-choose title items &optional event
     Prompt the user to choose an item from a list of options.

     TITLE is the name of the list of options.  ITEMS should be a menu,
     with its items in the simple format or in the extended format.
     *Note Defining Menus: (elisp)Defining Menus.  Independently of the
     format, you don’t have to provide a title for the menu, just pass
     the desired title in TITLE.  The optional EVENT is an input event.
     If EVENT is a mouse event and the number of elements in ITEMS is
     less than the user option ‘widget-menu-max-size’, then
     ‘widget-choose’ uses a popup menu to prompt the user.  Otherwise,
     ‘widget-choose’ uses the minibuffer.

     When ITEMS is a keymap menu, the returned value is the symbol in
     the key vector, as in the argument of ‘define-key’ (*note
     (elisp)Changing Key Bindings::).  When ITEMS is a list whose
     selectable items are of the form (NAME .  VALUE) (i.e., the
     simplified format), then the return value is the VALUE of the
     chosen element.

 -- Function: widget-image-find image
     Create a graphical button from IMAGE, an image or a file name sans
     extension.

     If IMAGE is a file name, the file should be in
     ‘widget-image-directory’, or in a place where ‘find-image’ will
     find it.

 -- Function: widget-image-insert widget tag image
     As part of WIDGET, insert the text TAG or, if supported, the image
     IMAGE.

     IMAGE should be as described in ‘widget-image-find’.

 -- Function: widget-echo-help pos
     Display help-echo text for the widget at POS.

     Uses the value of ‘:help-echo’.  If it is a function, it calls it
     to get a string.  Otherwise, it ‘eval’s it.

13 Customization
****************

This chapter is about the customization options for the Widget library,
for the end user.

 -- Face: widget-field-face
     Face used for other editing fields.

 -- Face: widget-button-face
     Face used for buttons.

 -- User Option: widget-mouse-face
     Face used for highlighting a button when the mouse pointer moves
     across it.

     The default value is ‘highlight’.

 -- User Option: widget-image-directory
     Directory where Widget should look for images.

     Widget will look here for a file with the same name as specified
     for the image, with either a ‘.xpm’ (if supported) or ‘.xbm’
     extension.

 -- User Option: widget-image-enable
     If non-‘nil’, allow images to appear on displays where they are
     supported.

 -- User Option: widget-image-conversion
     An alist to convert symbols from image formats to file name
     suffixes.

     Each element is a cons cell (FORMAT .  SUFFIX), where FORMAT is a
     symbol that represents an image format and SUFFIX is its
     correspondent suffix.

 -- User Option: widget-button-prefix
     String to prefix buttons.

 -- User Option: widget-button-suffix
     String to suffix buttons.

 -- User Option: widget-push-button-prefix
     String to prefix push buttons.

 -- User Option: widget-push-button-suffix
     String to suffix push buttons.

 -- User Option: widget-link-prefix
     String to prefix links.

 -- User Option: widget-link-suffix
     String to suffix links.

 -- User Option: widget-choice-toggle
     If non-‘nil’, toggle when there are just two options.

     By default, its value is ‘nil’.

 -- User Option: widget-documentation-links
     If non-‘nil’, add hyperlinks to documentation strings.

 -- User Option: widget-documentation-link-regexp
     A regexp that matches potential links in documentation strings.
     The link itself should match to the first group.

 -- User Option: widget-documentation-link-p
     A predicate function to test if a string is useful as a link.  The
     function is called with one argument, a string, and should return
     non-‘nil’ if there should be a link for that string.

     By default, the value is ‘intern-soft’.

 -- User Option: widget-documentation-link-type
     A symbol that represents a widget type to use for links in
     documentation strings.

     By default, the value is ‘documentation-link’.

 -- User Option: widget-menu-max-size
     Maximum size for a popup menu.  By default, its value is 40.

     If a function ask you to choose from a menu that is larger than
     this value, it will use the minibuffer.

 -- User Option: widget-menu-max-shortcuts
     Largest number of items for which it works to choose one with a
     character.

     For a larger number, use the minibuffer.

 -- User Option: widget-menu-minibuffer-flag
     Whether to use the minibuffer to ask for a choice.

     If ‘nil’, the default, read a single character.

14 Wishlist
***********

   • It should be possible to add or remove items from a list with ‘C-k’
     and ‘C-o’ (suggested by RMS).

   • The ‘[INS]’ and ‘[DEL]’ buttons should be replaced by a single dash
     (‘-’).  The dash should be a button that, when invoked, asks
     whether you want to add or delete an item (RMS wanted to git rid of
     the ugly buttons, the dash is my idea).

   • The ‘menu-choice’ tag should be prettier, something like the
     abbreviated menus in Open Look.

   • Finish ‘:tab-order’.

   • Make indentation work with glyphs and proportional fonts.

   • Add commands to show overview of object and class hierarchies to
     the browser.

   • Find a way to disable mouse highlight for inactive widgets.

   • Find a way to make glyphs look inactive.

   • Add ‘widget’ widget for editing widget specifications.

   • Find clean way to implement variable length list.  See
     ‘TeX-printer-list’ for an explanation.

   • ‘C-h’ in ‘widget-prompt-value’ should give type specific help.

   • Add a ‘mailto’ widget.

Appendix A GNU Free Documentation License
*****************************************

                     Version 1.3, 3 November 2008

     Copyright © 2000, 2001, 2002, 2007, 2008 Free Software Foundation, Inc.
     <https://fsf.org/>

     Everyone is permitted to copy and distribute verbatim copies
     of this license document, but changing it is not allowed.

  0. PREAMBLE

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     functional and useful document “free” in the sense of freedom: to
     assure everyone the effective freedom to copy and redistribute it,
     with or without modifying it, either commercially or
     noncommercially.  Secondarily, this License preserves for the
     author and publisher a way to get credit for their work, while not
     being considered responsible for modifications made by others.

     This License is a kind of “copyleft”, which means that derivative
     works of the document must themselves be free in the same sense.
     It complements the GNU General Public License, which is a copyleft
     license designed for free software.

     We have designed this License in order to use it for manuals for
     free software, because free software needs free documentation: a
     free program should come with manuals providing the same freedoms
     that the software does.  But this License is not limited to
     software manuals; it can be used for any textual work, regardless
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     instruction or reference.

  1. APPLICABILITY AND DEFINITIONS

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  5. COMBINING DOCUMENTS

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  10. FUTURE REVISIONS OF THIS LICENSE

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ADDENDUM: How to use this License for your documents
====================================================

To use this License in a document you have written, include a copy of
the License in the document and put the following copyright and license
notices just after the title page:

       Copyright (C)  YEAR  YOUR NAME.
       Permission is granted to copy, distribute and/or modify this document
       under the terms of the GNU Free Documentation License, Version 1.3
       or any later version published by the Free Software Foundation;
       with no Invariant Sections, no Front-Cover Texts, and no Back-Cover
       Texts.  A copy of the license is included in the section entitled ``GNU
       Free Documentation License''.

   If you have Invariant Sections, Front-Cover Texts and Back-Cover
Texts, replace the “with...Texts.” line with this:

         with the Invariant Sections being LIST THEIR TITLES, with
         the Front-Cover Texts being LIST, and with the Back-Cover Texts
         being LIST.

   If you have Invariant Sections without Cover Texts, or some other
combination of the three, merge those two alternatives to suit the
situation.

   If your document contains nontrivial examples of program code, we
recommend releasing these examples in parallel under your choice of free
software license, such as the GNU General Public License, to permit
their use in free software.

Index
*****

This is an alphabetical listing of all concepts, functions, commands,
variables, and widgets described in this manual.

* Menu:

* action keyword:                        Widget Gallery.     (line 1124)
* activate a widget:                     Widget Gallery.     (line 1083)
* activate keyword:                      Widget Gallery.     (line 1116)
* active keyword:                        Widget Gallery.     (line 1077)
* active widget:                         Widget Gallery.     (line 1083)
* alist:                                 composite.          (line 2387)
* append-button-args keyword:            editable-list.      (line 1932)
* args keyword:                          menu-choice.        (line 1538)
* args keyword <1>:                      radio-button-choice.
                                                             (line 1639)
* args keyword <2>:                      checklist.          (line 1867)
* args keyword <3>:                      editable-list.      (line 1954)
* atomic sexp widget:                    atoms.              (line 2142)
* basic widgets:                         Introduction.       (line   75)
* boolean:                               atoms.              (line 2242)
* button widgets:                        User Interface.     (line  202)
* button-args keyword:                   radio-button-choice.
                                                             (line 1626)
* button-args keyword <1>:               checklist.          (line 1857)
* button-face keyword:                   Widget Gallery.     (line  915)
* button-face-get keyword:               Widget Gallery.     (line 1050)
* button-prefix keyword:                 Widget Gallery.     (line  918)
* button-suffix keyword:                 Widget Gallery.     (line  918)
* buttons keyword:                       radio-button-choice.
                                                             (line 1630)
* buttons keyword <1>:                   checklist.          (line 1861)
* buttons keyword <2>:                   editable-list.      (line 1935)
* case-fold keyword:                     menu-choice.        (line 1525)
* character:                             atoms.              (line 2170)
* checkbox widget:                       checkbox.           (line 1785)
* checklist widget:                      checklist.          (line 1825)
* children keyword:                      menu-choice.        (line 1531)
* children keyword <1>:                  radio-button-choice.
                                                             (line 1633)
* children keyword <2>:                  checklist.          (line 1864)
* children keyword <3>:                  editable-list.      (line 1951)
* choice:                                composite.          (line 2291)
* choice keyword:                        menu-choice.        (line 1535)
* choice keyword <1>:                    radio-button-choice.
                                                             (line 1636)
* choice-item widget:                    choice-item.        (line 1683)
* coding-system:                         atoms.              (line 2260)
* color:                                 atoms.              (line 2248)
* completions-function keyword:          Widget Gallery.     (line 1028)
* composite sexp widgets:                composite.          (line 2275)
* cons:                                  composite.          (line 2282)
* const:                                 constants.          (line 2082)
* constant widgets:                      constants.          (line 2071)
* convert-widget keyword:                Defining New Widgets.
                                                             (line 2447)
* copy keyword:                          Widget Gallery.     (line 1067)
* create keyword:                        Widget Gallery.     (line  782)
* deactivate a widget:                   Widget Gallery.     (line 1083)
* deactivate keyword:                    Widget Gallery.     (line 1120)
* default:                               Widget Gallery.     (line  773)
* default-get keyword:                   Widget Gallery.     (line  869)
* define-widget:                         Defining New Widgets.
                                                             (line 2413)
* defining new widgets:                  Defining New Widgets.
                                                             (line 2409)
* delete keyword:                        Widget Gallery.     (line  792)
* delete-button-args keyword:            editable-list.      (line 1929)
* directory:                             atoms.              (line 2199)
* doc keyword:                           Widget Gallery.     (line  937)
* documentation-string widget:           documentation-string.
                                                             (line 2034)
* editable-field widget:                 editable-field.     (line 1378)
* editable-list widget:                  editable-list.      (line 1897)
* emacs-commentary-link widget:          emacs-commentary-link.
                                                             (line 1332)
* emacs-library-link widget:             emacs-library-link. (line 1319)
* embedded buttons:                      User Interface.     (line  219)
* entry-format keyword:                  radio-button-choice.
                                                             (line 1613)
* entry-format keyword <1>:              checklist.          (line 1847)
* entry-format keyword <2>:              editable-list.      (line 1913)
* example of using widgets:              Programming Example.
                                                             (line  253)
* external format:                       Widget Gallery.     (line  807)
* extra-offset keyword:                  Widget Gallery.     (line  973)
* face-link widget:                      face-link.          (line 1294)
* file:                                  atoms.              (line 2177)
* file-link widget:                      file-link.          (line 1306)
* float:                                 atoms.              (line 2230)
* follow-link keyword:                   Widget Gallery.     (line  956)
* format keyword:                        Widget Gallery.     (line  874)
* format-handler keyword:                Widget Gallery.     (line 1039)
* function:                              atoms.              (line 2210)
* function-item:                         constants.          (line 2101)
* function-link widget:                  function-link.      (line 1269)
* generic sexp widget:                   generic.            (line 2107)
* greedy keyword:                        checklist.          (line 1887)
* group widget:                          group.              (line 1991)
* help-echo keyword:                     Widget Gallery.     (line  947)
* inactive widget:                       Widget Gallery.     (line 1083)
* indent keyword:                        Widget Gallery.     (line  960)
* info-link widget:                      info-link.          (line 1256)
* insert-button-args keyword:            editable-list.      (line 1926)
* integer:                               atoms.              (line 2218)
* internal format:                       Widget Gallery.     (line  807)
* item widget:                           item.               (line 1168)
* key:                                   atoms.              (line 2267)
* keymap keyword:                        editable-field.     (line 1400)
* keyword arguments:                     Widget Gallery.     (line  780)
* lazy:                                  composite.          (line 2398)
* link widget:                           link.               (line 1207)
* list:                                  composite.          (line 2309)
* match keyword:                         Widget Gallery.     (line  989)
* menu-choice widget:                    menu-choice.        (line 1498)
* menu-tag keyword:                      Widget Gallery.     (line  977)
* menu-tag-get keyword:                  Widget Gallery.     (line  981)
* mouse-2 (on button widgets):           Widgets and the Buffer.
                                                             (line  740)
* mouse-down-action keyword:             Widget Gallery.     (line 1131)
* mouse-face-get keyword:                Widget Gallery.     (line 1058)
* must-match keyword:                    atoms.              (line 2187)
* natnum:                                atoms.              (line 2224)
* new widgets:                           Defining New Widgets.
                                                             (line 2409)
* notify keyword:                        Widget Gallery.     (line 1137)
* number:                                atoms.              (line 2236)
* off-glyph keyword:                     toggle.             (line 1732)
* offset keyword:                        Widget Gallery.     (line  969)
* on-glyph keyword:                      toggle.             (line 1728)
* option field tag:                      User Interface.     (line  212)
* other:                                 atoms.              (line 2253)
* parent keyword:                        Widget Gallery.     (line 1018)
* plist:                                 composite.          (line 2370)
* prompt-value keyword:                  Widget Gallery.     (line 1148)
* push-button widget:                    push-button.        (line 1345)
* radio:                                 composite.          (line 2305)
* radio-button-choice widget:            radio-button-choice.
                                                             (line 1589)
* radio-button-toggle widget:            radio-button-toggle.
                                                             (line 1750)
* regexp:                                atoms.              (line 2164)
* repeat:                                composite.          (line 2364)
* restricted-sexp:                       generic.            (line 2123)
* secret keyword:                        editable-field.     (line 1424)
* set:                                   composite.          (line 2350)
* sexp:                                  generic.            (line 2114)
* sexp types:                            Sexp Types.         (line 2064)
* sibling-args keyword:                  Widget Gallery.     (line 1022)
* size keyword:                          editable-field.     (line 1414)
* string:                                atoms.              (line 2158)
* symbol:                                atoms.              (line 2205)
* tab-order keyword:                     Widget Gallery.     (line 1004)
* tag keyword:                           Widget Gallery.     (line  940)
* tag-glyph keyword:                     Widget Gallery.     (line  943)
* text widget:                           text.               (line 1479)
* todo:                                  Widget Wishlist.    (line 2673)
* toggle widget:                         toggle.             (line 1705)
* url-link widget:                       url-link.           (line 1244)
* utility functions for widgets:         Utilities.          (line 2515)
* valid-regexp keyword:                  editable-field.     (line 1431)
* validate keyword:                      Widget Gallery.     (line  994)
* value keyword:                         Widget Gallery.     (line  807)
* value-create keyword:                  Widget Gallery.     (line  835)
* value-delete keyword:                  Widget Gallery.     (line  841)
* value-face keyword:                    editable-field.     (line 1419)
* value-get keyword:                     Widget Gallery.     (line  851)
* value-inline keyword:                  Widget Gallery.     (line  863)
* value-set keyword:                     Widget Gallery.     (line  855)
* value-to-external keyword:             Widget Gallery.     (line  829)
* value-to-internal keyword:             Widget Gallery.     (line  821)
* variable:                              atoms.              (line 2214)
* variable-item:                         constants.          (line 2098)
* variable-link widget:                  variable-link.      (line 1282)
* vector:                                composite.          (line 2320)
* void keyword:                          menu-choice.        (line 1519)
* widget browser:                        Inspecting Widgets. (line 2462)
* widget buttons:                        User Interface.     (line  202)
* widget creation, widget conversion:    Setting Up the Buffer.
                                                             (line  399)
* widget inheritance:                    Widgets Basics.     (line  355)
* widget library, why use it:            Introduction.       (line  116)
* widget minor mode:                     Widget Minor Mode.  (line 2501)
* widget object:                         Widgets Basics.     (line  349)
* widget properties:                     Widgets Basics.     (line  391)
* widget syntax:                         Widget Gallery.     (line  754)
* widget value:                          Widgets Basics.     (line  374)
* widget-apply:                          Working with Widgets.
                                                             (line  564)
* widget-apply-action:                   Working with Widgets.
                                                             (line  636)
* widget-at:                             Working with Widgets.
                                                             (line  558)
* widget-backward:                       Widgets and the Buffer.
                                                             (line  706)
* widget-browse:                         Inspecting Widgets. (line 2468)
* widget-browse-at:                      Inspecting Widgets. (line 2478)
* widget-browse-other-window:            Inspecting Widgets. (line 2473)
* widget-button-click:                   Widgets and the Buffer.
                                                             (line  741)
* widget-button-click <1>:               Widgets and the Buffer.
                                                             (line  741)
* widget-button-face:                    Customization.      (line 2582)
* widget-button-prefix:                  Customization.      (line 2610)
* widget-button-press:                   Widgets and the Buffer.
                                                             (line  731)
* widget-button-press <1>:               Widgets and the Buffer.
                                                             (line  731)
* widget-button-suffix:                  Customization.      (line 2613)
* widget-child-validate:                 Working with Widgets.
                                                             (line  647)
* widget-child-value-get:                Working with Widgets.
                                                             (line  605)
* widget-child-value-inline:             Working with Widgets.
                                                             (line  608)
* widget-children-validate:              Working with Widgets.
                                                             (line  653)
* widget-children-value-delete:          Setting Up the Buffer.
                                                             (line  482)
* widget-choice-toggle:                  Customization.      (line 2628)
* widget-choose:                         Utilities.          (line 2533)
* widget-complete:                       Widgets and the Buffer.
                                                             (line  722)
* widget-convert:                        Setting Up the Buffer.
                                                             (line  504)
* widget-copy:                           Setting Up the Buffer.
                                                             (line  494)
* widget-create:                         Setting Up the Buffer.
                                                             (line  414)
* widget-create-child:                   Setting Up the Buffer.
                                                             (line  443)
* widget-create-child-and-convert:       Setting Up the Buffer.
                                                             (line  433)
* widget-create-child-value:             Setting Up the Buffer.
                                                             (line  449)
* widget-default-delete:                 Widget Gallery.     (line  800)
* widget-default-format-handler:         Widget Gallery.     (line 1046)
* widget-default-get:                    Working with Widgets.
                                                             (line  592)
* widget-delete:                         Setting Up the Buffer.
                                                             (line  479)
* widget-describe:                       Inspecting Widgets. (line 2485)
* widget-documentation-link-p:           Customization.      (line 2640)
* widget-documentation-link-regexp:      Customization.      (line 2636)
* widget-documentation-link-type:        Customization.      (line 2647)
* widget-documentation-links:            Customization.      (line 2633)
* widget-echo-help:                      Utilities.          (line 2567)
* widget-end-of-line:                    Widgets and the Buffer.
                                                             (line  713)
* widget-field-activate:                 Widgets and the Buffer.
                                                             (line  726)
* widget-field-at:                       Working with Widgets.
                                                             (line  561)
* widget-field-face:                     Customization.      (line 2579)
* widget-field-keymap:                   editable-field.     (line 1400)
* widget-forward:                        Widgets and the Buffer.
                                                             (line  702)
* widget-get:                            Working with Widgets.
                                                             (line  548)
* widget-get-sibling:                    Utilities.          (line 2529)
* widget-global-map:                     Widgets and the Buffer.
                                                             (line  692)
* widget-image-conversion:               Customization.      (line 2602)
* widget-image-directory:                Customization.      (line 2591)
* widget-image-enable:                   Customization.      (line 2598)
* widget-image-find:                     Utilities.          (line 2553)
* widget-image-insert:                   Utilities.          (line 2561)
* widget-insert:                         Setting Up the Buffer.
                                                             (line  518)
* widget-keymap:                         Widgets and the Buffer.
                                                             (line  681)
* widget-kill-line:                      Widgets and the Buffer.
                                                             (line  718)
* widget-link-prefix:                    Customization.      (line 2622)
* widget-link-suffix:                    Customization.      (line 2625)
* widget-member:                         Working with Widgets.
                                                             (line  544)
* widget-menu-max-shortcuts:             Customization.      (line 2659)
* widget-menu-max-size:                  Customization.      (line 2653)
* widget-menu-minibuffer-flag:           Customization.      (line 2665)
* widget-minor-mode:                     Widget Minor Mode.  (line 2505)
* widget-minor-mode-keymap:              Widget Minor Mode.  (line 2509)
* widget-mouse-face:                     Customization.      (line 2585)
* widget-parent-action:                  Working with Widgets.
                                                             (line  642)
* widget-prompt-value:                   Utilities.          (line 2518)
* widget-push-button-prefix:             Customization.      (line 2616)
* widget-push-button-suffix:             Customization.      (line 2619)
* widget-put:                            Working with Widgets.
                                                             (line  554)
* widget-radio-add-item:                 radio-button-choice.
                                                             (line 1672)
* widget-setup:                          Setting Up the Buffer.
                                                             (line  466)
* widget-text-keymap:                    text.               (line 1491)
* widget-type:                           Working with Widgets.
                                                             (line  537)
* widget-type-default-get:               Working with Widgets.
                                                             (line  601)
* widget-type-match:                     Working with Widgets.
                                                             (line  658)
* widget-type-value-create:              Working with Widgets.
                                                             (line  615)
* widget-types-convert-widget:           Working with Widgets.
                                                             (line  670)
* widget-types-copy:                     Working with Widgets.
                                                             (line  664)
* widget-value:                          Working with Widgets.
                                                             (line  570)
* widget-value-convert-widget:           Working with Widgets.
                                                             (line  624)
* widget-value-set:                      Working with Widgets.
                                                             (line  583)
* widget-value-value-get:                Working with Widgets.
                                                             (line  629)
* widgetp:                               Working with Widgets.
                                                             (line  534)
* widgets, basic types:                  Introduction.       (line   75)
* widgets, programming example:          Programming Example.
                                                             (line  253)

RE: [External] : Editions to the Widget Manual

[Drew Adams]

> > Even a plain-text diff/patch would be more helpful
> 
> I've attached plain text versions (makeinfo --plaintext) with and
> without the patch as well as a diff -u contrasting them.  hth

Thanks, Corwin.

Re: Editions to the Widget Manual

[Eli Zaretskii]

> Date: Sun, 20 Aug 2023 07:31:46 -0300
> From: Mauro Aranda <maurooaranda@gmail.com>
> Cc: Drew Adams <drew.adams@oracle.com>, Bryce Carson <bovine@cyberscientist.ca>
> Prompted by [1], I started to work (slowly!) on a revision to the Widget
> Manual.

Thanks.

Do you think the version you have is good enough to install, perhaps
even on the emacs-29 release branch?

Re: Editions to the Widget Manual

[Mauro Aranda]

On 2/9/23 04:25, Eli Zaretskii wrote:
 >> Date: Sun, 20 Aug 2023 07:31:46 -0300
 >> From: Mauro Aranda <maurooaranda@gmail.com>
 >> Cc: Drew Adams <drew.adams@oracle.com>, Bryce Carson 
<bovine@cyberscientist.ca>
 >> Prompted by [1], I started to work (slowly!) on a revision to the Widget
 >> Manual.
 >
 > Thanks.
 >
 > Do you think the version you have is good enough to install, perhaps
 > even on the emacs-29 release branch?

I think is good enough, yes.  But I based the changes on what's on
master, so I'll have to check if some text needs to be different for the
release branch.

I'll send the patch as soon as I do that.

Re: Editions to the Widget Manual

[Eli Zaretskii]

> Date: Sat, 2 Sep 2023 07:15:20 -0300
> Cc: emacs-devel@gnu.org, drew.adams@oracle.com, bovine@cyberscientist.ca
> From: Mauro Aranda <maurooaranda@gmail.com>
> 
> On 2/9/23 04:25, Eli Zaretskii wrote:
>  > Do you think the version you have is good enough to install, perhaps
>  > even on the emacs-29 release branch?
> 
> I think is good enough, yes.  But I based the changes on what's on
> master, so I'll have to check if some text needs to be different for the
> release branch.
> 
> I'll send the patch as soon as I do that.

Thanks.

Re: Editions to the Widget Manual

[Mauro Aranda]

[-- Attachment #1: Type: text/plain, Size: 1109 bytes --]

On 2/9/23 07:26, Eli Zaretskii wrote:
 >> Date: Sat, 2 Sep 2023 07:15:20 -0300
 >> Cc: emacs-devel@gnu.org, drew.adams@oracle.com, bovine@cyberscientist.ca
 >> From: Mauro Aranda <maurooaranda@gmail.com>
 >>
 >> On 2/9/23 04:25, Eli Zaretskii wrote:
 >>  > Do you think the version you have is good enough to install, perhaps
 >>  > even on the emacs-29 release branch?
 >>
 >> I think is good enough, yes.  But I based the changes on what's on
 >> master, so I'll have to check if some text needs to be different for the
 >> release branch.
 >>
 >> I'll send the patch as soon as I do that.
 >
 > Thanks.

Thanks to you for taking a look at this, really.  I'm just happy to be
able to contribute something back to Emacs.

As for the changes, I didn't need to adapt anything for the emacs-29
branch.  I attach a patch against it, in which I also incorporated the
change suggested by Yuan Fu of moving the default widget to its own
subsection.  My next step would be to come up with short examples
demonstrating how to use the more important widgets and functions.
Hopefully it doesn't take me too long.

[-- Attachment #2: 0001-A-revision-to-the-Widget-manual.patch --]
[-- Type: text/x-patch, Size: 115549 bytes --]

From 5a19d4fe4a48f38c3bdee7ed8eb93c78c542b9d9 Mon Sep 17 00:00:00 2001
From: Mauro Aranda <maurooaranda@gmail.com>
Date: Sat, 2 Sep 2023 07:55:12 -0300
Subject: [PATCH] A revision to the Widget manual

* doc/misc/widget.texi (Widgets Basics, Working with Widgets)
(Widgets and the Buffer, Widget Gallery, Customization): New chapters.
(Basic Types, Sexp Types): Demote to subsections.
(Widget Browser): Rename to Inspecting Widgets.
(Widget Properties): Remove.

(Top): Adapt menu to changes.
(Introduction): Rearrange text.  Move warnings to a better place, and
user options to the Customization chapter.
(User Interface): Don't fully describe commands and customization
options here.
(Setting Up the Buffer): Expand on widget creation process and add
documentation for useful functions which deal with
creation/conversion.
(Defining New Widgets): Expand the documentation on define-widget.
All relevant properties moved to the description of the default
widget, in Widget Gallery.
(Utilities): Add some more useful functions not previously documented.
(Wishlist): Remove out-of-date items.
---
 doc/misc/widget.texi | 2779 +++++++++++++++++++++++++++++++-----------
 1 file changed, 2070 insertions(+), 709 deletions(-)

diff --git a/doc/misc/widget.texi b/doc/misc/widget.texi
index 13b37ab5b54..eb411f29c5c 100644
--- a/doc/misc/widget.texi
+++ b/doc/misc/widget.texi
@@ -49,14 +49,16 @@ Top
 * Introduction::
 * User Interface::
 * Programming Example::
+* Widgets Basics::
 * Setting Up the Buffer::
-* Basic Types::
-* Sexp Types::
-* Widget Properties::
+* Working with Widgets::
+* Widgets and the Buffer::
+* Widget Gallery::
 * Defining New Widgets::
-* Widget Browser::
+* Inspecting Widgets::
 * Widget Minor Mode::
 * Utilities::
+* Customization::
 * Widget Wishlist::
 * GNU Free Documentation License::
 * Index::
@@ -68,7 +70,7 @@ Introduction
 Most graphical user interface toolkits provide a number of standard
 user interface controls (sometimes known as ``widgets'' or ``gadgets'').
 Emacs doesn't really support anything like this, except for an
-incredibly powerful text ``widget.''  On the other hand, Emacs does
+incredibly powerful text ``widget''.  On the other hand, Emacs does
 provide the necessary primitives to implement many other widgets
 within a text buffer.  The @code{widget} package simplifies this task.
 
@@ -85,13 +87,13 @@ Introduction
 @item editable-field
 An editable text field.  It can be either variable or fixed length.
 @item menu-choice
-Allows the user to choose one of multiple options from a menu, each
-option is itself a widget.  Only the selected option will be visible in
-the buffer.
+Allows the user to choose one of multiple options from a menu, where
+each option is itself a widget.  Only the selected option is visible
+in the buffer.
 @item radio-button-choice
 Allows the user to choose one of multiple options by activating radio
-buttons.  The options are implemented as widgets.  All options will be
-visible in the buffer.
+buttons.  The options are implemented as widgets.  All options are
+visible in the buffer, with the selected one marked as chosen.
 @item item
 A simple constant widget intended to be used in the @code{menu-choice} and
 @code{radio-button-choice} widgets.
@@ -137,9 +139,9 @@ Introduction
 Packages using the library get a uniform look, making them easier for
 the user to learn.
 @item
-As support for embedded graphics improve, the widget library will be
+As support for embedded graphics improve, the Widget library will be
 extended to use the GUI features.  This means that your code using the
-widget library will also use the new graphic features automatically.
+Widget library will also use the new graphic features automatically.
 @end enumerate
 
 @node User Interface
@@ -201,12 +203,6 @@ User Interface
 
 Editable text fields are created by the @code{editable-field} widget.
 
-@strong{Warning:} In an @code{editable-field} widget, the editable
-field must not be adjacent to another widget---that won't work.
-You must put some text in between.  Either make this text part of
-the @code{editable-field} widget itself, or insert it with
-@code{widget-insert}.
-
 The @code{:format} keyword is useful for generating the necessary
 text; for instance, if you give it a value of @code{"Name: %v "},
 the @samp{Name: } part will provide the necessary separating text
@@ -215,17 +211,9 @@ User Interface
 @code{:size} keyword, the field will extend to the end of the
 line, and the terminating newline will provide separation after.
 
-@strong{Warning:} In an @code{editable-field} widget, the @samp{%v} escape
-must be preceded by some other text in the @code{:format} string
-(if specified).
-
 The editing text fields are highlighted with the
 @code{widget-field-face} face, making them easy to find.
 
-@deffn Face widget-field-face
-Face used for other editing fields.
-@end deffn
-
 @section Buttons
 
 @cindex widget buttons
@@ -233,24 +221,9 @@ User Interface
 Some portions of the buffer have an associated @dfn{action}, which can
 be @dfn{invoked} by a standard key or mouse command.  These portions
 are called @dfn{buttons}.  The default commands for activating a button
-are:
-
-@table @kbd
-@item @key{RET}
-@deffn Command widget-button-press @var{pos} &optional @var{event}
-Invoke the button at @var{pos}, defaulting to point.
-If point is not located on a button, invoke the binding in
-@code{widget-global-map} (by default the global map).
-@end deffn
-
-@kindex mouse-2 @r{(on button widgets})
-@item mouse-2
-@deffn Command widget-button-click @var{event}
-Invoke the button at the location of the mouse pointer.  If the mouse
-pointer is located in an editable text field, invoke the binding in
-@code{widget-global-map} (by default the global map).
-@end deffn
-@end table
+are @code{widget-button-press} and @code{widget-button-click}.  The
+user typically interacts with the buttons with a key, like @key{RET},
+or with the mouse buttons.
 
 There are several different kind of buttons, all of which are present in
 the example:
@@ -286,33 +259,15 @@ User Interface
 displayed as GUI buttons when possible.
 @end table
 
-To make them easier to locate, buttons are emphasized in the buffer.
-
-@deffn Face widget-button-face
-Face used for buttons.
-@end deffn
-
-@defopt widget-mouse-face
-Face used for highlighting a button when the mouse pointer moves across
-it.
-@end defopt
+To make them easier to locate, buttons are emphasized in the buffer
+with a distinctive face, like @code{widget-button-face} or
+@code{widget-mouse-face}.
 
 @section Navigation
 
 You can use all the normal Emacs commands to move around in a form
-buffer, plus you will have these additional commands:
-
-@table @kbd
-@item @key{TAB}
-@deffn Command widget-forward &optional count
-Move point @var{count} buttons or editing fields forward.
-@end deffn
-@item @kbd{M-@key{TAB}}
-@itemx @kbd{S-@key{TAB}}
-@deffn Command widget-backward &optional count
-Move point @var{count} buttons or editing fields backward.
-@end deffn
-@end table
+buffer, plus you will have these additional commands to navigate from
+widget to widget: @code{widget-forward} and @code{widget-backward}.
 
 @node Programming Example
 @chapter Programming Example
@@ -414,315 +369,1050 @@ Programming Example
   (widget-setup))
 @end lisp
 
+@node Widgets Basics
+@chapter Widgets Basics
+@cindex widget object
+The Widget Library deals with widgets objects.  A widget object has
+properties whose value may be anything, be it numbers, strings,
+symbols, functions, etc.  Those properties are referred to as keywords
+and are responsible for the way a widget is represented in a buffer,
+and control the way a user or a program can interact with it.
+
+@cindex widget inheritance
+The library defines several widget types, and gives you a way to
+define new types as well.  In addition, widgets can derive from other
+types, creating a sort of widget inheritance.  In fact, all widgets
+defined in the Widget Library share a common parent, the @dfn{default}
+widget.  In this manual, when we talk about a default behavior, we
+usually mean the behavior as defined by this @code{default} widget.
+@xref{Widget Gallery}, for a description of each defined widget.
+
+Defining a new type that derives from a previous one is not mandatory
+to create widgets that work very different from a specified type.
+When creating a widget, you can override any default property,
+including functions, that control the widget.  That is, you can
+specialize a widget on creation, without having to define it as a new
+type of widget.
+
+In addition to the function for defining a widget, this library
+provides functions to create widgets, query and change its properties,
+respond to user events and destroy them.  The following sections
+describe them.
+
+@cindex widget value
+One important property of a widget is its @dfn{value}.  All widgets
+may have a value,  which is stored in a so-called @dfn{internal format}.
+For the rest of Emacs, the widget presents its value in a so-called
+@dfn{external format}.  Both formats can be equal or different, and
+each widget is responsible for defining how the conversion between
+each format should happen.
+
+@c FIXME: Briefly describe inline widgets?
+@c The inline concept is described elsewhere, and it's difficult to
+@c describe.
+
+The value property is an important property for almost all widgets,
+and perhaps more important for @code{editable-field} widgets.  This
+type of widgets allow the user to edit them via the usual editing
+commands in Emacs.  They can also be edited programmatically.
+@strong{Important:} You @emph{must} call @code{widget-setup} after
+modifying the value of a widget before the user is allowed to edit the
+widget again.  It is enough to call @code{widget-setup} once if you
+modify multiple widgets.  This is currently only necessary if the widget
+contains an editing field, but may be necessary for other widgets in the
+future.
+
+@cindex widget properties
+If your application needs to associate some information with the widget
+objects, for example a reference to the item being edited, it can be
+done with the @code{widget-put} and @code{widget-get} functions.  The
+property names, as shown, are keywords, so they must begin with a
+@samp{:}.
+
 @node Setting Up the Buffer
 @chapter Setting Up the Buffer
+@cindex widget creation, widget conversion
+To show the widgets in a buffer, you have to create them.  Widget
+creation is actually a two-step process: conversion and creation per
+se.  With simple projects, usually the conversion step isn't really
+important, and you only care about widget creation, so feel free to
+skip the conversion description until you really need to know it.
+
+Widget conversion is the process that involves taking a widget
+specification and transforming it into a @dfn{widget} object, suitable
+to be created, queried and manipulated with other widget functions.
+Widget creation is the process that takes a widget object and actually
+inserts it in the buffer.
+
+The simplest function to create a widget is @code{widget-create}, which
+gets a widget specification and returns a widget object.
+
+@defun widget-create type [ keyword argument ]@dots{} args
+Create and return a widget of type @var{type}, converting it.
+
+@var{type} is a symbol that specifies a widget type.  @var{keyword}
+may be one of the properties supported by the widget type, and
+@var{argument} specify the value for that property.  These keyword
+arguments can be used to overwrite the keyword arguments that are part
+of @var{type} by default, as well as to provide other properties not
+present in @var{type} by default.  @var{args} holds additional
+information for the creation of @var{type} and each widget type is
+responsible for handling that information in a specific way.
+
+The syntax for the @var{type} argument is described in @ref{Widget
+Gallery}, and in more detail in every widget where it's relevant.
+@end defun
+
+There are other functions for creating widgets, useful when you work
+with composite widgets.  That is, widgets that are part of other
+widgets.
 
-Widgets are created with @code{widget-create}, which returns a
-@dfn{widget} object.  This object can be queried and manipulated by
-other widget functions, until it is deleted with @code{widget-delete}.
-After the widgets have been created, @code{widget-setup} must be called
-to enable them.
+@defun widget-create-child-and-convert parent type &rest args
+Create a widget of type @var{type} as a child of @var{parent}.
 
-@defun widget-create type [ keyword argument ]@dots{}
-Create and return a widget of type @var{type}.
-The syntax for the @var{type} argument is described in @ref{Basic Types}.
+Before creating it, converts @var{type} using the keyword arguments
+provided in @var{args}.
+@c FIXME: Is this description useful?
+Adds the @code{:indent} property, unless it is already present, and
+sets it to the sum of the values of: @code{:indent} and @code{:offset}
+from @var{parent} and @code{:extra-offset} from @var{type}.
 
-The keyword arguments can be used to overwrite the keyword arguments
-that are part of @var{type}.
+Returns a widget object, with the property @code{:parent} set to
+@var{PARENT}.
 @end defun
 
-@defun widget-delete widget
-Delete @var{widget} and remove it from the buffer.
+@defun widget-create-child parent type
+Create a widget of type @var{type} as a child of @var{parent}.
+
+This function is like @code{widget-create-child-and-convert} but it
+doesn't convert @var{type}, so it expects an already converted widget.
 @end defun
 
+@defun widget-create-child-value parent type value
+Create a widget of type @var{type} as a child of @var{parent} with
+value @var{value}.
+
+This function is like @code{widget-create-child}, but it lets you
+specify a value for the widget.
+
+Converts @var{value} to the internal format, as specified by
+@var{type}, and stores it into the @code{:value} property of @var{type}.
+That means, @var{value} should be in the external format, as
+specified by @var{type}.
+@end defun
+
+All these creating functions described here use the function stored in
+the @code{:create} property.  So, to modify the creation logic for a
+widget, you can provide a different @code{:create} function.
+
+When you're done creating widgets and you're ready for the user to
+interact with the buffer, use the function @code{widget-setup}.
+
 @defun widget-setup
-Set up a buffer to support widgets.
+Setup the current buffer, so that editable widgets can be edited.
 
 This should be called after creating all the widgets and before allowing
 the user to edit them.
 @end defun
 
-If you want to insert text outside the widgets in the form, the
-recommended way to do that is with @code{widget-insert}.
+As mentioned, all these functions return a widget object.  That widget
+object can be queried and manipulated with widget functions that
+take widgets as arguments, until deleting it with the widgets
+functions available to delete widgets.  Even if you don't save the
+returned widget object, you still can interact programmatically with
+the widget.  @xref{Working with Widgets}.
 
-@defun widget-insert
-Insert the arguments, either strings or characters, at point.
-The inserted text will be read-only.
+@defun widget-delete widget
+Delete the widget @var{widget} and remove it from the buffer.
 @end defun
 
-There is a standard widget keymap which you might find useful.
+@defun widget-children-value-delete widget
+Delete all children and buttons in widget @var{widget}.
 
-@findex widget-button-press
-@findex widget-button-click
-@defvr Const widget-keymap
-@key{TAB} and @kbd{C-@key{TAB}} are bound to @code{widget-forward} and
-@code{widget-backward}, respectively.  @key{RET} and @kbd{mouse-2}
-are bound to @code{widget-button-press} and
-@code{widget-button-click}.
-@end defvr
+This function does not delete @var{widget} itself, only the widgets
+stored in the @code{:children} and @code{:buttons} properties.  It
+also sets those properties to @code{nil}.
+@end defun
 
-@defvar widget-global-map
-Keymap used by @code{widget-button-press} and @code{widget-button-click}
-when not on a button.  By default this is @code{global-map}.
-@end defvar
+As with the creation mechanism, the function stored in @code{:delete}
+controls the deletion mechanism for a widget.
 
-@node Basic Types
-@chapter Basic Types
+Additionally, the library provides a way to make a copy of a widget.
 
-This is the general syntax of a type specification:
+@defun widget-copy widget
+Makes a copy of widget @var{widget} and returns it.
 
-@example
-@var{name} ::= (@var{name} [@var{keyword} @var{argument}]... @var{args})
-     |   @var{name}
-@end example
+It uses the function stored in the @code{:copy} property of @var{widget}
+and returns the widget that that function returns.
+@end defun
 
-Where, @var{name} is a widget name, @var{keyword} is the name of a
-property, @var{argument} is the value of the property, and @var{args}
-are interpreted in a widget specific way.
+As discussed, there is a conversion step when creating a widget.  To
+do the conversion without actually creating the widget, you can use
+the @code{widget-convert} function.
 
-@cindex keyword arguments
-The following keyword arguments apply to all widgets:
+@defun widget-convert type &rest args
+Convert @var{type} to a widget object, using keyword arguments @var{args}.
 
-@table @code
-@cindex internal format
-@cindex external format
-@vindex value@r{ keyword}
-@item :value
-The initial value for widgets of this type.  Typically, a widget
-represents its value in two formats: external and internal.  The
-external format is the value as the rest of Emacs sees it, and the
-internal format is a representation that the widget defines and uses
-in a widget specific way.
+Returns a widget object, suitable for creation.  It calls the function
+stored in the @code{:convert-widget} property, after putting into the
+@code{:args} property the arguments that the widget in question needs.
+If @var{type} has a @code{:value} property, either originally or after
+doing the conversion, this function converts the value stored in
+@code{:value} to the internal format, and stores it into @code{:value}.
+@end defun
 
-Both formats might be the same for certain widgets and might differ
-for others, and there is no guarantee about which format the value
-stored in the @code{:value} property has.  However, when creating a
-widget or defining a new one (@pxref{Defining New Widgets}), the
-@code{:value} should be in the external format.
+Apart from only creating widgets in the buffer, It's useful to have
+plain text.  For inserting text, the recommended way is with the
+@code{widget-insert} function.
 
-@vindex format@r{ keyword}
-@item :format
-This string will be inserted in the buffer when you create a widget.
-The following @samp{%} escapes are available:
+@defun widget-insert &rest args
+Insert @var{args}, either strings or characters, at point.
 
-@table @samp
-@item %[
-@itemx %]
-The text inside will be marked as a button.
+Uses @code{insert} to perform the insertion, passing @var{args} as
+argument.  @xref{Insertion,,,elisp, the Emacs Lisp Reference Manual},
+for more information about @var{args}.
 
-By default, the text will be shown in @code{widget-button-face}, and
-surrounded by brackets.
+The resulting text will be read-only.
+@end defun
 
-@defopt widget-button-prefix
-String to prefix buttons.
-@end defopt
+@node Working with Widgets
+@chapter Working with Widgets
+This section covers the more important functions needed to query and
+manipulate widgets in a generic way.  Widgets may have additional
+functions for interacting with them, those are described in the
+description for each widget.  @xref{Widget Gallery}.
 
-@defopt widget-button-suffix
-String to suffix buttons.
-@end defopt
+@defun widgetp widget
+Non-@code{nil} if @var{widget} is a widget.
+@end defun
 
-@item %@{
-@itemx %@}
-The text inside will be displayed with the face specified by
-@code{:sample-face}.
+@defun widget-type widget
+Return the type of widget @var{widget}, a symbol.
 
-@item %v
-This will be replaced with the buffer representation of the widget's
-value.  What this is depends on the widget type.
+This function is useful to find out which kind of widget @var{widget}
+represents, i.e., the name of the widget type when the widget
+was created.
+@end defun
 
-@strong{Warning:} In an @code{editable-field} widget, the @samp{%v} escape
-must be preceded by some other text in the format string (if specified).
+@defun widget-member widget property
+Non-@code{nil} if widget @var{widget} has a value (even @code{nil}) for
+property @var{property}.
+@end defun
 
-@item %d
-Insert the string specified by @code{:doc} here.
+@defun widget-get widget property
+For widget @var{widget}, return the value of the property @var{property}.
 
-@item %h
-Like @samp{%d}, with the following modifications: If the documentation
-string is more than one line, it will add a button which will toggle
-between showing only the first line, and showing the full text.
-Furthermore, if there is no @code{:doc} property in the widget, it will
-instead examine the @code{:documentation-property} property.  If it is a
-lambda expression, it will be called with the widget's value as an
-argument, and the result will be used as the documentation text.
+@var{property} should be a keyword, and the value is what was last set by
+@code{widget-put} for @var{property}.
+@end defun
 
-@item %t
-Insert the string specified by @code{:tag} here, or the @code{princ}
-representation of the value if there is no tag.
+@defun widget-put widget property value
+For widget @var{widget}, set the property @var{property} to @var{value}.
+@var{property} should be a keyword, while @var{value} can be anything.
+@end defun
 
-@item %%
-Insert a literal @samp{%}.
-@end table
+@defun widget-at &optional pos
+Return the widget at position @var{pos}, or at point if @var{pos} is @code{nil}.
+@end defun
 
-@vindex button-face@r{ keyword}
-@item :button-face
-Face used to highlight text inside %[ %] in the format.
+@defun widget-field-at pos
+Return the widget field at position POS, or @code{nil} if there is none.
+@end defun
 
-@vindex button-prefix@r{ keyword}
-@vindex button-suffix@r{ keyword}
-@item :button-prefix
-@itemx :button-suffix
-Text around %[ %] in the format.
+@defun widget-apply widget property &rest args
+Apply the function stored in @var{property} to @var{widget}, passing @var{args}
+as additional arguments to the function.
 
-These can be
-@table @emph
-@item nil
-No text is inserted.
+Returns the result of that function call.
+@end defun
 
-@item a string
-The string is inserted literally.
+@defun widget-value widget
+Return the current value contained in @var{widget}.
 
-@item a symbol
-The value of the symbol is expanded according to this table.
-@end table
+Note that the value returned by this function might differ from what's
+stored in the @code{:value} property of @var{widget}.  This is because
+this function extracts the current value of @var{widget} from the
+buffer, taking editions into account.
 
-@vindex doc@r{ keyword}
-@item :doc
-The string inserted by the @samp{%d} escape in the format
-string.
+The value returned is in the external format, after getting it with
+the @code{:value-get} function.
 
-@vindex tag@r{ keyword}
-@item :tag
-The string inserted by the @samp{%t} escape in the format
-string.
+It is an error to call this function on an uninitialized widget.
+@end defun
 
-@vindex tag-glyph@r{ keyword}
-@item :tag-glyph
-Name of image to use instead of the string specified by @code{:tag} on
-Emacsen that supports it.
+@defun widget-value-set widget value
+Set the value contained in @var{widget} to @var{value}.
 
-@vindex help-echo@r{ keyword}
-@item :help-echo
-Specifies how to display a message whenever you move to the widget with
-either @code{widget-forward} or @code{widget-backward} or move the mouse
-over it (using the standard @code{help-echo} mechanism).  The argument
-is either a string to display, a function of one argument, the widget,
-which should return a string to display, or a form that evaluates to
-such a string.
+Converts @var{value} to the internal format, and then sets it by
+applying the @code{:value-set} function.
 
-@vindex follow-link@r{ keyword}
-@item :follow-link
-Specifies how to interpret a @key{mouse-1} click on the widget.
-@xref{Clickable Text,, Defining Clickable Text, elisp, the Emacs Lisp Reference Manual}.
+It is an error to call this function with an invalid @var{value}, that
+is, a value that @var{widget} cannot represent.
+@end defun
 
-@vindex indent@r{ keyword}
-@item :indent
-An integer indicating the absolute number of spaces to indent children
-of this widget.
+@defun widget-default-get widget
+Return the default external value of widget @var{widget}.
 
-@vindex offset@r{ keyword}
-@item :offset
-An integer indicating how many extra spaces to add to the widget's
-grandchildren compared to this widget.
+The default value is the one stored in @code{:value} or the result of
+applying the @code{:default-get} function to the arguments of
+@var{widget}, as stored in @code{:args}.  A value of @code{nil} is
+ignored by default, so in order for a widget to respect @code{nil} as
+a value, it has to override the @code{:default-get} function.
+@end defun
 
-@vindex extra-offset@r{ keyword}
-@item :extra-offset
-An integer indicating how many extra spaces to add to the widget's
-children compared to this widget.
+@defun widget-type-default-get widget
+Convert the @code{:type} attribute in @var{widget} and return its
+default value.
+@end defun
 
-@vindex notify@r{ keyword}
-@item :notify
-A function called each time the widget or a nested widget is changed.
-The function is called with two or three arguments.  The first argument
-is the widget itself, the second argument is the widget that was
-changed, and the third argument is the event leading to the change, if
-any.
+@defun widget-child-value-get widget
+Return the value of the first member of @code{:children} in
+@var{widget}.
+@end defun
 
-@vindex menu-tag@r{ keyword}
-@item :menu-tag
-Tag used in the menu when the widget is used as an option in a
-@code{menu-choice} widget.
+@defun widget-child-value-inline widget
+Return the inline value of the first member of @code{:children} in
+@var{widget}.
 
-@vindex menu-tag-get@r{ keyword}
-@item :menu-tag-get
-Function used for finding the tag when the widget is used as an option
-in a @code{menu-choice} widget.  By default, the tag used will be either the
-@code{:menu-tag} or @code{:tag} property if present, or the @code{princ}
-representation of the @code{:value} property if not.
+The inline value is whatever the function stored in
+@code{:value-inline} returns.
+@end defun
 
-@vindex match@r{ keyword}
-@item :match
-Should be a function called with two arguments, the widget and an
-external value, and should return non-@code{nil} if the widget can
-represent the specified value.
+@defun widget-type-value-create widget
+Create a child widget for @var{widget}, of type stored in
+@code{:type}.
 
-@vindex validate@r{ keyword}
-@item :validate
-A function which takes a widget as an argument, and returns @code{nil}
-if the widget's current value is valid for the widget.  Otherwise it
-should return the widget containing the invalid data, and set that
-widget's @code{:error} property to a string explaining the error.
+Creates the child widget taking the value from the @code{:value}
+property and stores the newly created widget in the @code{:children}
+property of @var{widget}.
+
+The value stored in @code{:type} should be an unconverted widget
+type.
+@end defun
 
-The following predefined function can be used:
+@defun widget-value-convert-widget widget
+Initializes the @code{:value} property of @var{widget} from
+@code{:args}.
 
-@defun widget-children-validate widget
-All the @code{:children} of @var{widget} must be valid.
+Sets @code{:args} to @code{nil} and returns the modified widget
+@var{widget}.
 @end defun
 
-@vindex tab-order@r{ keyword}
-@item :tab-order
-Specify the order in which widgets are traversed with
-@code{widget-forward} or @code{widget-backward}.  This is only partially
-implemented.
+@defun widget-value-value-get widget
+Return the value stored in @code{:value} for widget @var{widget}.
 
-@enumerate a
-@item
-Widgets with tabbing order @code{-1} are ignored.
+This is different to getting the current value for @var{widget} with
+@code{widget-value}, since that function extracts the value from the
+buffer.
+@end defun
 
-@item
-(Unimplemented) When on a widget with tabbing order @var{n}, go to the
-next widget in the buffer with tabbing order @var{n+1} or @code{nil},
-whichever comes first.
+@defun widget-apply-action widget &optional event
+Apply the function stored in @code{:action} to @var{widget}, in
+response to @var{event}.
 
-@item
-When on a widget with no tabbing order specified, go to the next widget
+It is an error to call this function with an inactive widget.
+@end defun
+
+@defun widget-parent-action widget &optional event
+Tell @code{:parent} of @var{widget} to handle @var{event}.
+
+Optional @var{event} is the event that triggered the action.
+@end defun
+
+@defun widget-child-validate widget
+Check that the first member of @code{:children} in @var{widget} is valid.
+
+To be valid means that the widget value passes the checks that the
+function stored in @code{:validate} makes.
+@end defun
+
+@defun widget-children-validate widget
+Check that all @code{:children} in @var{widget} are valid.
+
+Returns @code{nil} on success, or the first child that isn't valid.
+@end defun
+
+@defun widget-type-match widget value
+Return non-@code{nil} if @var{VALUE} matches the value for the
+@code{:type} widget.
+
+As with the other type functions, the widget stored in @code{:type}
+should be an unconverted widget.
+@end defun
+
+@defun widget-types-copy widget
+Copy the @code{:args} value in @var{widget} and store them in @code{:args}.
+
+Makes the copies by calling @code{widget-copy} on each element present
+in @code{:args}.  Returns the modified widget @var{widget}.
+@end defun
+
+@defun widget-types-convert-widget widget
+Convert the @code{:args} value in @var{widget} and store them in
+@code{args}.
+
+Returns the modified widget @var{widget}.
+@end defun
+
+@node Widgets and the Buffer
+@chapter Widgets and the Buffer
+This chapter describes commands that are specific to buffers that
+contain widgets.
+
+@cindex widget keybindings
+@defvr Const widget-keymap
+Keymap containing useful bindings for buffers containing widgets.
+
+Binds @key{TAB} and @kbd{C-@key{TAB}} to @code{widget-forward} and
+@code{widget-backward}, respectively.  It also binds @key{RET} to
+@code{widget-button-press} and @kbd{down-mouse-1} and
+@kbd{down-mouse-2} to @code{widget-button-click}.
+@end defvr
+
+There's also a keymap for events that the Widget library doesn't need
+to handle.
+
+@defvar widget-global-map
+Keymap used by @code{widget-button-press} and @code{widget-button-click}
+when not on a button.  By default this is @code{global-map}.
+@end defvar
+
+In addition to these two keymaps, each widget might define a keymap of
+its own, active when events happen at that widget.
+
+@cindex widget navigation
+The following navigation commands are available:
+
+@table @kbd
+@item @key{TAB}
+@deffn Command widget-forward &optional count
+Move point @var{count} buttons or editing fields forward.
+@end deffn
+@item @kbd{M-@key{TAB}}
+@itemx @kbd{S-@key{TAB}}
+@deffn Command widget-backward &optional count
+Move point @var{count} buttons or editing fields backward.
+@end deffn
+@end table
+
+
+When editing an @code{editable-field} widget, the following commands
+are available:
+
+@table @kbd
+@item @key{C-e}
+@deffn Command widget-end-of-line
+Move point to the end of field or end of line, whichever is first.
+@end deffn
+
+@item @kbd{C-k}
+@deffn Command widget-kill-line
+Kill to end of field or end of line, whichever is first.
+@end deffn
+
+@item @kbd{M-TAB}
+@deffn Command widget-complete
+Complete the content of the editable field at point.
+@end deffn
+
+@item @kbd{C-m}
+@deffn Command widget-field-activate
+Invoke the editable field at point.
+@end deffn
+@end table
+
+The following two are commands that can execute widget actions.
+@table @kbd
+@item @key{RET}
+@findex widget-button-press
+@deffn Command widget-button-press @var{pos} &optional @var{event}
+Invoke the button at @var{pos}, defaulting to point.
+
+Invocation means to run the function stored in the @code{:action}
+property.
+
+If point is not located on a button, invoke the binding in
+@code{widget-global-map} (by default the global map).
+@end deffn
+
+@kindex mouse-2 @r{(on button widgets})
+@item mouse-2
+@findex widget-button-click
+@deffn Command widget-button-click @var{event}
+Invoke the button at the location of the mouse pointer.
+
+If the mouse pointer is located in an editable text field, invoke the
+binding in @code{widget-global-map} (by default the global map).
+
+In case the mouse-click is on a widget, calls the function stored in
+the @code{:mouse-down-action} property.
+@end deffn
+@end table
+
+@node Widget Gallery
+@chapter Widget Gallery
+@cindex widget syntax
+All widgets can be created from a type specification.  The general
+syntax of a type specification is:
+
+@c FIXME: Add BNF reference here? If yes, what reference?
+@example
+@var{name} ::= (@var{name} [@var{keyword} @var{argument}]... @var{args})
+     |   @var{name}
+@end example
+
+Where @var{name} is a widget name, as defined with
+@code{define-widget}, @var{keyword} is the name of a property and
+@var{argument} is the value for that property, and @var{args} are
+interpreted in a widget specific way.  @xref{Defining New Widgets}.
+
+@menu
+* Basic Types::
+* Sexp Types::
+@end menu
+
+@node Basic Types
+@section Basic Types
+
+@menu
+* default::
+* item::
+* link::
+* url-link::
+* info-link::
+* function-link::
+* variable-link::
+* face-link::
+* file-link::
+* emacs-library-link::
+* emacs-commentary-link::
+* push-button::
+* editable-field::
+* text::
+* menu-choice::
+* radio-button-choice::
+* choice-item::
+* toggle::
+* radio-button-toggle::
+* checkbox::
+* checklist::
+* editable-list::
+* group::
+* documentation-string::
+@end menu
+
+@node default
+@subsection The @code{default} Widget
+@findex default@r{ widget}
+The most basic widget in the Widget Library is the @dfn{default}
+widget.  It provides the basic behavior for all other widgets, and all
+its properties are present by default in derived widgets.  You're
+seldom (if ever) going to effectively create a default widget, but
+here we describe its properties and behavior, so that we can describe
+other widgets only by mentioning the properties and behavior those
+other widgets specialize.
+
+@deffn Widget default
+Widget used as a base for other widgets.
+
+It provides most of the functionality that is referred to as ``by
+default'' in this text.  If you want to define a new widget from
+scratch, use the @code{default} widget as its base.
+@end deffn
+
+@cindex keyword arguments
+The following keyword arguments apply to all widgets:
+
+@table @code
+@vindex create@r{ keyword}
+@item :create
+Function to create a widget from scratch.
+
+The function takes one argument, a widget type, and creates a widget
+of that type, inserts it in the buffer, and returns a widget object.
+
+By default, it inserts the widget at point, using the format provided
+in the @code{:format} property.
+
+@vindex delete@r{ keyword}
+@item :delete
+Function to delete a widget.
+
+The function should take one argument, a widget, and should remove all
+traces of the widget from the buffer.
+
+The default value is:
+
+@defun widget-default-delete widget
+Remove @var{widget} from the buffer.
+Delete all @code{:children} and @code{:buttons} in @var{widget}.
+@end defun
+
+In most cases you should not change this value, but instead use
+@code{:value-delete} to make any additional cleanup.
+
+@cindex internal format
+@cindex external format
+@vindex value@r{ keyword}
+@item :value
+The initial value for widgets of this type.
+
+Typically, a widget represents its value in two formats: external and
+internal.  The external format is the value as the rest of Emacs sees
+it, and the internal format is a representation that the widget
+defines and uses in a widget specific way.
+
+Both formats might be the same for certain widgets and might differ
+for others, and there is no guarantee about which format the value
+stored in the @code{:value} property has.  However, when creating a
+widget or defining a new one (@pxref{Defining New Widgets}), the
+@code{:value} should be in the external format.
+
+@vindex value-to-internal@r{ keyword}
+@item :value-to-internal
+Function to convert the value to the internal format.
+
+The function takes two arguments, a widget and an external value, and
+returns the internal value.  The function is called on the present
+@code{:value} when the widget is created, and on any value set later
+with @code{widget-value-set}.
+
+@vindex value-to-external@r{ keyword}
+@item :value-to-external
+Function to convert the value to the external format.
+
+The function takes two arguments, a widget and an internal value, and
+returns the value in the external format.
+
+@vindex value-create@r{ keyword}
+@item :value-create
+Function to expand the @samp{%v} escape in the format string.
+
+It will be called with the widget as its argument and should insert a
+representation of the widget's value in the buffer.
+
+@vindex value-delete@r{ keyword}
+@item :value-delete
+A function that should remove the representation of the widget's value
+from the buffer.
+
+It will be called with the widget as its argument.  It doesn't have to
+remove the text, but it should release markers and delete nested widgets
+if these are not listed in @code{:children} or @code{:buttons}.
+
+By default, it's a no-op.
+
+@vindex value-get@r{ keyword}
+@item :value-get
+Function to extract the value of a widget, as it is displayed in the
+buffer.
+
+@vindex value-set@r{ keyword}
+@item :value-set
+Function that takes a widget and a value as arguments, and recreates
+it.
+
+The value must already be in the internal format for widget.  By
+default, it deletes the widget with the @code{:delete} function and
+creates it again with the @code{:create} function.
+
+@vindex value-inline@r{ keyword}
+@item :value-inline
+Function that takes a widget and returns its value, inlined.
+
+Inlined means that if the widget is not inline (i.e., its
+@code{:inline} property is @code{nil}), the return value is wrapped in
+a list.
+
+@vindex default-get@r{ keyword}
+@item :default-get
+Function that takes a widget and returns its default value.
+
+By default, it just returns the value stored in @code{:value}.
+
+@vindex format@r{ keyword}
+@item :format
+This string will be inserted in the buffer when you create a widget.
+The following @samp{%} escapes are available:
+
+@table @samp
+@item %[
+@itemx %]
+The text inside will be marked as a button.
+
+By default, the text will be shown in @code{widget-button-face}, and
+surrounded by brackets.
+
+@item %@{
+@itemx %@}
+The text inside will be displayed with the face specified by
+@code{:sample-face}.
+
+@item %v
+This will be replaced with the buffer representation of the widget's
+value.  What this is depends on the widget type.
+
+@item %d
+Insert the string specified by @code{:doc} here.
+
+@item %h
+Like @samp{%d}, with the following modifications: If the documentation
+string is more than one line, it will add a button which will toggle
+between showing only the first line, and showing the full text.
+Furthermore, if there is no @code{:doc} property in the widget, it will
+instead examine the @code{:documentation-property} property.  If it is a
+lambda expression, it will be called with the widget's value as an
+argument, and the result will be used as the documentation text.
+
+@item %t
+Insert the string specified by @code{:tag} here, or the @code{princ}
+representation of the value if there is no tag.
+
+@item %%
+Insert a literal @samp{%}.
+@end table
+
+@vindex button-face@r{ keyword}
+@item :button-face
+Face used to highlight text inside %[ %] in the format.
+
+@vindex button-prefix@r{ keyword}
+@vindex button-suffix@r{ keyword}
+@item :button-prefix
+@itemx :button-suffix
+Strings used as prefix and suffix for widgets that are buttons.
+
+By default, the values are @code{widget-button-prefix} and
+@code{widget-button-suffix}.
+
+Text around %[ %] in the format.
+
+These can be
+@table @emph
+@item nil
+No text is inserted.
+
+@item a string
+The string is inserted literally.
+
+@item a symbol
+The value of the symbol is expanded according to this table.
+@end table
+
+@vindex doc@r{ keyword}
+@item :doc
+The string inserted by the @samp{%d} escape in the format
+string.
+
+@vindex tag@r{ keyword}
+@item :tag
+The string inserted by the @samp{%t} escape in the format
+string.
+
+@vindex tag-glyph@r{ keyword}
+@item :tag-glyph
+Name of image to use instead of the string specified by @code{:tag} on
+Emacsen that supports it.
+
+@vindex help-echo@r{ keyword}
+@item :help-echo
+Specifies how to display a message whenever you move to the widget with
+either @code{widget-forward} or @code{widget-backward} or move the mouse
+over it (using the standard @code{help-echo} mechanism).
+
+The value is either a string to display, or a function of one
+argument, the widget.  If a function, it should return a string to
+display, or a form that evaluates to such a string.
+
+@vindex follow-link@r{ keyword}
+@item :follow-link
+Specifies how to interpret a @key{mouse-1} click on the widget.
+@xref{Clickable Text,, Defining Clickable Text, elisp, the Emacs Lisp Reference Manual}.
+
+@vindex indent@r{ keyword}
+@item :indent
+An integer indicating the absolute number of spaces to indent children
+of this widget.  Its value might be @code{nil} too, which corresponds
+to a value of 0.
+
+The default @code{:create} functions and the functions that create the
+value per se use this property as a rudimentary layout mechanism for
+the widgets.
+
+@vindex offset@r{ keyword}
+@item :offset
+An integer indicating how many extra spaces to add to the widget's
+grandchildren compared to this widget.
+
+@vindex extra-offset@r{ keyword}
+@item :extra-offset
+An integer indicating how many extra spaces to add to the widget's
+children compared to this widget.
+
+@vindex menu-tag@r{ keyword}
+@item :menu-tag
+Tag used in the menu when the widget is used as an option in a
+@code{menu-choice} widget.
+
+@vindex menu-tag-get@r{ keyword}
+@item :menu-tag-get
+Function that takes a widget and returns the tag when the widget is
+used as an option in a @code{menu-choice} widget.
+
+By default, the tag used will be either the @code{:menu-tag} or
+@code{:tag} property if present, or the @code{princ} representation of
+the @code{:value} property if not.
+
+@vindex match@r{ keyword}
+@item :match
+Should be a function called with two arguments, the widget and an
+external value, and should return non-@code{nil} if the widget can
+represent the specified value.
+
+@vindex validate@r{ keyword}
+@item :validate
+A function which takes a widget as an argument, and returns @code{nil}
+if the widget's current value is valid for the widget.
+
+Otherwise, it should return the widget containing the invalid data,
+and set that widget's @code{:error} property to a string explaining
+the error.
+
+By default, it always returns @code{nil}.
+
+@vindex tab-order@r{ keyword}
+@item :tab-order
+Specify the order in which widgets are traversed with
+@code{widget-forward} or @code{widget-backward}.  This is only partially
+implemented.
+@enumerate a
+@item
+Widgets with tabbing order @code{-1} are ignored.
+
+@item
+(Unimplemented) When on a widget with tabbing order @var{n}, go to the
+next widget in the buffer with tabbing order @var{n+1} or @code{nil},
+whichever comes first.
+
+@item
+When on a widget with no tabbing order specified, go to the next widget
 in the buffer with a positive tabbing order, or @code{nil}
 @end enumerate
 
-@vindex parent@r{ keyword}
-@item :parent
-The parent of a nested widget (e.g., a @code{menu-choice} item or an
-element of a @code{editable-list} widget).
+@vindex parent@r{ keyword}
+@item :parent
+The parent of a nested widget (e.g., a @code{menu-choice} item or an
+element of a @code{editable-list} widget).
+
+@vindex sibling-args@r{ keyword}
+@item :sibling-args
+This keyword is only used for members of a @code{radio-button-choice} or
+@code{checklist}.  The value should be a list of extra keyword
+arguments, which will be used when creating the @code{radio-button} or
+@code{checkbox} associated with this item.
+
+@vindex completions-function@r{ keyword}
+@item :completions-function
+Function that takes a widget and returns completion data for that
+widget, like @code{completion-at-point-functions} would.
+@xref{Completion,,,elisp, the Emacs Lisp Reference Manual}.  It's
+used by @code{editable-field} widgets to provide completions.
+
+By default, it looks into the property @code{:completions}, which
+should be a completion table.  If @code{:completions} is @code{nil},
+then it calls the function stored either in the @code{:complete} or
+@code{:complete-function} property.
+
+@vindex format-handler@r{ keyword}
+@item :format-handler
+Function to handle unknown @samp{%} escapes in the format string.
+
+It takes a widget and the character that follows the @samp{%} as
+arguments.  You can set this to allow your widget to handle
+non-standard escapes in your own specialized widgets.
+
+@findex widget-default-format-handler
+You should end up calling @code{widget-default-format-handler} to handle
+unknown escape sequences, which will handle the @samp{%h} and any future
+escape sequences, as well as give an error for unknown escapes.
+
+@vindex button-face-get@r{ keyword}
+@item :button-face-get
+Function to return the face used to fontify a widget button.
+
+Takes a widget and returns an appropriate face for the widget.  By
+default, it either returns the face stored in the @code{:button-face}
+property, or calls the @code{:button-face-get} function from the
+parent of the widget, if it has one.
+
+@vindex mouse-face-get@r{ keyword}
+@item :mouse-face-get
+Function to return the face used to fontify a widget when the mouse
+pointer hovers over it.
+
+Takes a widget and returns an appropriate face.  By default, it either
+returns the face stored in the @code{:mouse-face} property, or calls
+the @code{:button-face-get} function from the parent of the widget, if
+it has one.
+
+@vindex copy@r{ keyword}
+@item :copy
+Function to deep copy a widget type.
+
+It takes a shallow copy of the widget type as an argument (made by
+@code{copy-sequence}), and returns a deep copy.  The purpose of this
+is to avoid having different instances of combined widgets share
+nested attributes.
+
+Its value by default is @code{identity}.
+
+@vindex active@r{ keyword}
+@item :active
+Function that takes a widget and returns @code{t} if it is active.
+
+A widget might be effectively always active, if its
+@code{:always-active} property is @code{t}.
+
+@cindex active widget
+@cindex inactive widget
+@cindex activate a widget
+@cindex deactivate a widget
+Widgets can be in two states: active, which means they are modifiable by
+the user, or inactive, which means they cannot be modified by the user.
+You can query or set the state with the following code:
+
+@lisp
+;; Examine if @var{widget} is active or not.
+(if (widget-apply @var{widget} :active)
+    (message "Widget is active.")
+  (message "Widget is inactive.")
+
+;; Make @var{widget} inactive.
+(widget-apply @var{widget} :deactivate)
+
+;; Make @var{widget} active.
+(widget-apply @var{widget} :activate)
+@end lisp
+
+A widget is inactive if it, or any of its ancestors (found by
+following the @code{:parent} link), have been deactivated.  To make sure
+a widget is really active, you must therefore activate both it and
+all its ancestors.
+
+@lisp
+(while widget
+  (widget-apply widget :activate)
+  (setq widget (widget-get widget :parent)))
+@end lisp
+
+You can check if a widget has been made inactive by examining the value
+of the @code{:inactive} keyword.  If this is non-@code{nil}, the widget itself
+has been deactivated.  This is different from using the @code{:active}
+keyword, in that the latter tells you if the widget @strong{or} any of
+its ancestors have been deactivated.  Do not attempt to set the
+@code{:inactive} keyword directly.  Use the @code{:activate}
+@code{:deactivate} functions instead.
+
+@vindex activate@r{ keyword}
+@item :activate
+Function that takes a widget and makes it active for user
+modifications.
+
+@vindex deactivate@r{ keyword}
+@item :deactivate
+Function that takes a widget and makes it inactive for user
+modifications.
+
+@vindex action@r{ keyword}
+@item :action
+Function that takes a widget and optionally an event, and handles a
+user initiated event.
+
+By default, uses the @code{:notify} function to notify the widget's
+parent about the event.
+
+@vindex mouse-down-action@r{ keyword}
+@item :mouse-down-action
+Function that takes a widget and optionally an event, and handles a
+mouse click on the widget.
+
+By default, it does nothing.
+
+@vindex notify@r{ keyword}
+@item :notify
+A function called each time the widget or a nested widget is changed.
+
+The function is called with two or three arguments.  The first argument
+is the widget itself, the second argument is the widget that was
+changed, and the third argument is the event leading to the change, if
+any.
+
+By default, it passes the notification to the widget's parent.
+
+@vindex prompt-value@r{ keyword}
+@item :prompt-value
+Function to prompt for a value in the minibuffer.
+
+The function should take four arguments, a widget, a prompt (a
+string), a value and a boolean, and should return a value for the
+widget, entered by the user.
+
+The prompt is the prompt to use.  The value is the default value to
+use, unless the fourtha argument is non-@code{nil}, in which case
+there is no default value.
+
+The function should read the value using the method most natural for
+this widget, and does not have to check that it matches.
+@end table
+
+@node item
+@subsection The @code{item} Widget
+@findex item@r{ widget}
+
+Syntax:
+
+@example
+@var{type} ::= (item [@var{keyword} @var{argument}]... @var{value})
+@end example
 
-@vindex sibling-args@r{ keyword}
-@item :sibling-args
-This keyword is only used for members of a @code{radio-button-choice} or
-@code{checklist}.  The value should be a list of extra keyword
-arguments, which will be used when creating the @code{radio-button} or
-@code{checkbox} associated with this item.
+A useful widget that holds a constant value, and can be included in
+other widgets.  Its super is the @code{default} widget.
 
-@end table
+As can be seen in the syntax, the @code{item} widget is one of the
+widget that handles the @var{args} argument to @code{widget-create} in
+a specific way.  If present, @var{value} is used to initialize the
+@code{:value} property.  When created, it inserts the value as a
+string in the buffer.
 
-@deffn {User Option} widget-image-directory
-Directory where Widget should look for images.
-Widget will look here for a file with the same name as specified for the
-image, with either a @file{.xpm} (if supported) or @file{.xbm} extension.
-@end deffn
+By default, it has the following properties:
 
-@deffn{User Option} widget-image-enable
-If non-@code{nil}, allow images to appear on displays where they are supported.
-@end deffn
+@table @code
+@item :convert-widget
+The function that allows it to handle @var{value}.
 
+@item :value-create
+Prints the representation of @code{:value} in the buffer.
 
-@menu
-* link::
-* url-link::
-* info-link::
-* push-button::
-* editable-field::
-* text::
-* menu-choice::
-* radio-button-choice::
-* item::
-* choice-item::
-* toggle::
-* checkbox::
-* checklist::
-* editable-list::
-* group::
-@end menu
+@item :value-get
+Returns the value stored in @code{:value}.
+
+@item :match
+A value matches the @code{item} widget if it's @code{equal} to its
+@code{:value}.
+
+@item :match-inline
+Inline values match the @code{item} widget if @code{:value} is a
+sublist of values.
+
+@item :action
+The @code{item} widget notifies itself of an event.
+
+@item :format
+By default, the @code{item} widget inserts its tag in the buffer.
+@end table
 
 @node link
-@section The @code{link} Widget
+@subsection The @code{link} Widget
 @findex link@r{ widget}
 
 Syntax:
@@ -731,22 +1421,42 @@ link
 @var{type} ::= (link [@var{keyword} @var{argument}]...  [ @var{value} ])
 @end example
 
+A widget to represent an embedded link.  Its super is the @code{item}
+widget.
+
 The @var{value}, if present, is used to initialize the @code{:value}
 property.  The value should be a string, which will be inserted in the
 buffer.
 
-By default the link will be shown in brackets.
+By default, it has the following properties:
 
-@defopt widget-link-prefix
-String to prefix links.
-@end defopt
+@table @code
+@item :button-prefix
+The value of @code{widget-link-prefix}.
 
-@defopt widget-link-suffix
-String to suffix links.
-@end defopt
+@item :button-suffix
+The value of @code{widget-link-suffix}.
+
+@item :keymap
+A custom keymap for the link widget, so that it can respond to mouse clicks.
+
+@item :follow-link
+This property allows the link to respect the value of
+@code{mouse-1-click-follows-link}.  @xref{Clickable Text,,,elisp, the Emacs Lisp Reference Manual}.
+
+@item :format
+Buttonizes the link, to make it clickable.
+
+If you override this property, you should make sure to provide the
+@samp{%[} and @samp{%]} escape sequences, so that the link is
+clickable.
+
+@end table
+
+By default the link will be shown in brackets.
 
 @node url-link
-@section The @code{url-link} Widget
+@subsection The @code{url-link} Widget
 @findex url-link@r{ widget}
 
 Syntax:
@@ -755,12 +1465,14 @@ url-link
 @var{type} ::= (url-link [@var{keyword} @var{argument}]...  @var{url})
 @end example
 
-@findex browse-url-browser-function@r{, and @code{url-link} widget}
-When this link is invoked, the @acronym{WWW} browser specified by
-@code{browse-url-browser-function} will be called with @var{url}.
+A widget to represent a link to a web page.  Its super is the
+@code{link} widget.
+
+It overrides the @code{:action} property to open up the @var{url}
+specified.
 
 @node info-link
-@section The @code{info-link} Widget
+@subsection The @code{info-link} Widget
 @findex info-link@r{ widget}
 
 Syntax:
@@ -769,11 +1481,104 @@ info-link
 @var{type} ::= (info-link [@var{keyword} @var{argument}]...  @var{address})
 @end example
 
-When this link is invoked, the built-in Info reader is started on
-@var{address}.
+A widget to represent a link to an info file.  Its super is the
+@code{link} widget.
+
+It overrides the @code{:action} property, to a function to start the
+built-in Info reader on @var{address}, when invoked.
+
+@node function-link
+@subsection The @code{function-link} Widget
+@findex function-link@r{ widget}
+Syntax:
+
+@example
+@var{type} ::= (function-link [@var{keyword} @var{argument}]...  @var{function})
+@end example
+
+A widget to represent a link to an Emacs function.  Its super is the
+@code{link} widget.
+
+It overrides the @code{:action} property, to a function to describe
+@var{function}.
+
+@node variable-link
+@subsection The @code{variable-link} Widget
+@findex variable-link@r{ widget}
+Syntax:
+
+@example
+@var{type} ::= (variable-link [@var{keyword} @var{argument}]...  @var{var})
+@end example
+
+A widget to represent a link to an Emacs variable.  Its super is the
+@code{link} widget.
+
+It overrides the @code{:action} property, to a function to describe
+@var{var}.
+
+@node face-link
+@subsection The @code{face-link} Widget
+@findex face-link@r{ widget}
+Syntax:
+
+@example
+@var{type} ::= (face-link [@var{keyword} @var{argument}]...  @var{face})
+@end example
+
+A widget to represent a link to an Emacs face.  Its super is the
+@code{link} widget.
+
+It overrides the @code{:action} property, to a function to describe
+@var{face}.
+
+@node file-link
+@subsection The @code{file-link} Widget
+@findex file-link@r{ widget}
+Syntax:
+
+@example
+@var{type} ::= (file-link [@var{keyword} @var{argument}]...  @var{file})
+@end example
+
+A widget to represent a link to a file.  Its super is the
+@code{link} widget.
+
+It overrides the @code{:action} property, to a function to find the file
+@var{file}.
+
+@node emacs-library-link
+@subsection The @code{emacs-library-link} Widget
+@findex emacs-library-link@r{ widget}
+Syntax:
+
+@example
+@var{type} ::= (emacs-library-link [@var{keyword} @var{argument}]...  @var{file})
+@end example
+
+A widget to represent a link to an Emacs Lisp file.  Its super is the
+@code{link} widget.
+
+It overrides the @code{:action} property, to a function to find the file
+@var{file}.
+
+@node emacs-commentary-link
+@subsection The @code{emacs-commentary-link} Widget
+@findex emacs-commentary-link@r{ widget}
+Syntax:
+
+@example
+@var{type} ::= (emacs-commentary-link [@var{keyword} @var{argument}]...  @var{file})
+@end example
+
+A widget to represent a link to the Comment section of an Emacs Lisp
+file.  Its super is the @code{link} widget.
+
+It overrides the @code{:action} property, to a function to find the file
+@var{file} and put point in the Comment section.
 
 @node  push-button
-@section The @code{push-button} Widget
+@subsection The @code{push-button} Widget
 @findex push-button@r{ widget}
 
 Syntax:
@@ -782,22 +1587,37 @@ push-button
 @var{type} ::= (push-button [@var{keyword} @var{argument}]...  [ @var{value} ])
 @end example
 
+A widget that acts as a pushable button.  Its super is the @code{item}
+widget.
+
 The @var{value}, if present, is used to initialize the @code{:value}
 property.  The value should be a string, which will be inserted in the
 buffer.
 
-By default the tag will be shown in brackets.
+By default, it has the following properties:
+@table @code
+@item :button-prefix
+The empty string.
 
-@defopt widget-push-button-prefix
-String to prefix push buttons.
-@end defopt
+@item :button-suffix
+The empty string.
 
-@defopt widget-push-button-suffix
-String to suffix push buttons.
-@end defopt
+@item :value-create
+Inserts a representation of the ``on'' and ``off'' states for the push
+button.
+
+The representation might be an image, stored in the @code{:tag-glyph}
+property, or text.  If it is text, it might be the value of the
+@code{:tag} property, or the @code{:value} of the widget, surrounded
+with @code{widget-push-button-prefix} and
+@code{widget-push-button-suffix}.  @xref{Customization}.
+
+@item :format
+Buttonizes the widget, to make it clickable.
+@end table
 
 @node editable-field
-@section The @code{editable-field} Widget
+@subsection The @code{editable-field} Widget
 @findex editable-field@r{ widget}
 
 Syntax:
@@ -806,56 +1626,137 @@ editable-field
 @var{type} ::= (editable-field [@var{keyword} @var{argument}]... [ @var{value} ])
 @end example
 
+A widget that can be edited by the user.  Its super is the
+@code{default} widget.
+
 The @var{value}, if present, is used to initialize the @code{:value}
 property.  The value should be a string, which will be inserted in the
-field.  This widget will match all string values.
+field.  If not present, @code{:value} is the empty string.
+
+@strong{Warning:} In an @code{editable-field} widget, the editable
+field must not be adjacent to another widget---that won't work.
+You must put some text in between.  Either make this text part of
+the @code{editable-field} widget itself, or insert it with
+@code{widget-insert}.
 
-The following extra properties are recognized:
+This widget either overrides or adds the following properties:
 
 @table @code
+@item :convert-widget
+Just like the @code{item} widget, this function allows it to
+initialize @code{:value} from @var{value}.
+
+@vindex keymap@r{ keyword}
+@vindex widget-field-keymap
+@item :keymap
+Keymap used in the editable field.
+
+The default value is @code{widget-field-keymap}, which allows the user
+to use all the normal editing commands, even if the buffer's major
+mode suppresses some of them.  Pressing @key{RET} invokes the function
+specified by @code{:action}.
+
+@item :format
+By default, it specifies to insert only the widget's value.
+
+@strong{Warning:} In an @code{editable-field} widget, the @samp{%v} escape
+must be preceded by some other text in the @code{:format} string (if
+specified).
+
 @vindex size@r{ keyword}
 @item :size
-The width of the editable field.@*
+The width of the editable field.
+
 By default the field will reach to the end of the line.
 
 @vindex value-face@r{ keyword}
 @item :value-face
-Face used for highlighting the editable field.  Default is
-@code{widget-field-face}, see @ref{User Interface}.
+Face used for highlighting the editable field.
+
+Default is @code{widget-field-face}, @pxref{User Interface}.
 
 @vindex secret@r{ keyword}
 @item :secret
-Character used to display the value.  You can set this to, e.g., @code{?*}
-if the field contains a password or other secret information.  By
-default, this is @code{nil}, and the value is not secret.
+Character used to display the value.
+
+You can set this to, e.g., @code{?*} if the field contains a password
+or other secret information.  By default, this is @code{nil}, and the
+value is not secret.
 
 @vindex valid-regexp@r{ keyword}
 @item :valid-regexp
 By default the @code{:validate} function will match the content of the
-field with the value of this attribute.  The default value is @code{""}
-which matches everything.
+field with the value of this attribute.
 
-@vindex keymap@r{ keyword}
-@vindex widget-field-keymap
-@item :keymap
-Keymap used in the editable field.  The default value is
-@code{widget-field-keymap}, which allows you to use all the normal
-editing commands, even if the buffer's major mode suppresses some of
-them.  Pressing @key{RET} invokes the function specified by
-@code{:action}.
+The default value is @code{""} which matches everything.
+
+@item :validate
+Returns @code{nil} if the current value of the widget matches the
+@code{:valid-regexp} value.
+
+@item :prompt-internal
+A function to read a value for widget, used by the
+@code{:prompt-value} function.
+
+@item :prompt-history
+A variable that holds the history of field minibuffer edits.
+
+@item :prompt-value
+A function that uses the @code{:prompt-internal} function and the
+@code{:prompt-history} value to prompt for a string, and retun the
+user response in the external format.
+
+@item :action
+When invoked, moves point to the next field.
+
+@item :value-create
+Function that takes care of creating the widget, respecting its
+@code{:size} and @code{:value}.
+
+@item :value-set
+Function to use to modify programatically the current value of the
+widget.
+
+@item :value-delete
+Function that removes the widget so it cannot be edited anymore.
+
+@item :value-get
+Function to return the current text in the widget.
+
+It takes an optional argument, @var{no-truncate}.  If
+@var{no-truncate} is nil, truncates trailing spaces.
+
+@item :match
+Function that makes the widget match any string value.
 @end table
 
 @node text
-@section The @code{text} Widget
+@subsection The @code{text} Widget
 @findex text@r{ widget}
 
+Syntax:
+
+@example
+@var{type} ::= (text [@var{keyword} @var{argument}]... [ @var{value} ])
+@end example
+
+A widget just like the @code{editable-field} widget, but intended for
+multiline text fields.  Its super is the @code{editable-field} widget.
+
+It overrides the following properties:
+
+@table @code
+@item :format
+By default, prints a tag and the value.
+
 @vindex widget-text-keymap
-This is just like @code{editable-field}, but intended for multiline text
-fields.  The default @code{:keymap} is @code{widget-text-keymap}, which
-does not rebind the @key{RET} key.
+@item :keymap
+The default is @code{widget-text-keymap}, which does not rebind the
+@key{RET} key.
+@end table
 
 @node menu-choice
-@section The @code{menu-choice} Widget
+@subsection The @code{menu-choice} Widget
 @findex menu-choice@r{ widget}
 
 Syntax:
@@ -864,21 +1765,37 @@ menu-choice
 @var{type} ::= (menu-choice [@var{keyword} @var{argument}]... @var{type} ... )
 @end example
 
+A widget to represent a menu of options.  Its super is the
+@code{default} widget.
+
 The @var{type} argument represents each possible choice.  The widget's
-value will be that of the chosen @var{type} argument.  This widget will
-match any value matching at least one of the specified @var{type}
-arguments.
+value will be that of the chosen @var{type} argument.
+
+It either overrides or adds the following properties:
 
 @table @code
+@item :convert-widget
+A function that takes care of converting each possible choice.
+
+@item :copy
+A function to copy each possible choice.
+
+@item :format
+By default, buttonize the tag and show the value.
+
 @vindex void@r{ keyword}
 @item :void
 Widget type used as a fallback when the value does not match any of the
 specified @var{type} arguments.
 
+By default this is an @code{item} widget.
+
 @vindex case-fold@r{ keyword}
 @item :case-fold
-Set this to @code{nil} if you don't want to ignore case when prompting for a
-choice through the minibuffer.
+If @code{nil} don't ignore case when prompting for a choice through
+the minibuffer.
+
+By default, its value is @code{t}.
 
 @vindex children@r{ keyword}
 @item :children
@@ -892,10 +1809,54 @@ menu-choice
 @vindex args@r{ keyword}
 @item :args
 The list of types.
+
+@item :value-create
+The function that inserts the current value for the widget.
+
+It inserts the first choice that matches, as with the @code{:match}
+function, the value of the widget.
+
+@item :value-get
+Returns the value of the first child for the widget (see the
+description for @code{:children} above).
+
+@item :value-inline
+Returns the inline value of the first child for the widget.
+
+@item :default-get
+The default value for this widget is the default value for the first
+choice, in case @code{:value} is missing.
+
+This means that if you want a specific default value for the
+@code{menu-choice} widget, you should either pass a @code{:value}
+property when creating it, or arrange the choices so that the first
+one can hold your desired default value.
+
+@item :mouse-down-action
+A function that takes care of showing a menu, if possible and desired.
+
+@item :action
+A function that takes care of getting a new choice for the widget.
+
+Depending on the number of choices available, it may show a menu or
+just toggle the choices, or even do nothing at all.
+
+After getting the choice, it recreates the widget and notifies it.
+
+@item :validate
+Returns @code{nil} if the widget's value is a valid choice.
+
+@item :match
+This widget will match any value matching at least one of the
+specified @var{type} arguments.
+
+@item :match-inline
+A function that returns non-@code{nil} if the values match the widget,
+taking into account the @code{:inline} property.
 @end table
 
 @node radio-button-choice
-@section The @code{radio-button-choice} Widget
+@subsection The @code{radio-button-choice} Widget
 @findex radio-button-choice@r{ widget}
 
 Syntax:
@@ -904,14 +1865,28 @@ radio-button-choice
 @var{type} ::= (radio-button-choice [@var{keyword} @var{argument}]...  @var{type} ... )
 @end example
 
-The component types specify the choices, with one radio button for
+A widget to represent a choice from multiple options.  Its super is
+the @code{default} widget.
+
+The component @var{types} specify the choices, with one radio button for
 each.  The widget's value will be that of the chosen @var{type}
-argument.  This widget matches any value that matches at least one of
-the specified @var{type} arguments.
+argument.
 
-The following extra properties are recognized.
+It overrides the following properties:
 
 @table @code
+@item :convert-widget
+As other composite widgets, a function that takes care of converting
+each available choice.
+
+@item :copy
+A function to copy each available choice.
+
+@item :action
+A function that checks if any radio button was pressed and activates
+the pressed one, possibly deactivating an old one.  Then, it notifies
+itself.
+
 @vindex entry-format@r{ keyword}
 @item :entry-format
 This string will be inserted for each entry in the list.
@@ -925,6 +1900,9 @@ radio-button-choice
 Insert a literal @samp{%}.
 @end table
 
+@item :format
+By default, it inserts its value.
+
 @vindex button-args@r{ keyword}
 @item :button-args
 A list of keywords to pass to the radio buttons.  Useful for setting,
@@ -940,42 +1918,55 @@ radio-button-choice
 
 @vindex choice@r{ keyword}
 @item :choice
-The current chosen type
+The current chosen type.
 
 @vindex args@r{ keyword}
 @item :args
 The list of types.
-@end table
 
-You can add extra radio button items to a @code{radio-button-choice}
-widget after it has been created with the function
-@code{widget-radio-add-item}.
+@item :value-create
+A function to insert all available choices.
 
-@defun widget-radio-add-item widget type
-Add to @code{radio-button-choice} widget @var{widget} a new radio button
-item of type @var{type}.
-@end defun
+@item :value-get
+Returns the value for the chosen widget.
 
-Please note that such items added after the @code{radio-button-choice}
-widget has been created will @strong{not} be properly destructed when
-you call @code{widget-delete}.
+@item :value-set
+A function to set the value to one of its available options.
 
-@node item
-@section The @code{item} Widget
-@findex item@r{ widget}
+@item :value-inline
+A function that returns the inline value of the child widget.
 
-Syntax:
+@item :offset
+By default, this widget has an offset of 4.
 
-@example
-@var{item} ::= (item [@var{keyword} @var{argument}]... @var{value})
-@end example
+@item :validate
+The widget validates if the current value is valid for one of its
+children.
+
+@item :match
+This widget matches any value that matches at least one of
+the specified @var{type} arguments.
+
+@item :match-inline
+Like the @code{:match} function, but taking into account inline
+values.
+@end table
+
+You can add extra radio button items to a @code{radio-button-choice}
+widget after it has been created with the function
+@code{widget-radio-add-item}.
+
+@defun widget-radio-add-item widget type
+Add to @code{radio-button-choice} widget @var{widget} a new radio button
+item of type @var{type}.
+@end defun
 
-The @var{value}, if present, is used to initialize the @code{:value}
-property.  The value should be a string, which will be inserted in the
-buffer.  This widget will only match the specified value.
+Please note that such items added after the @code{radio-button-choice}
+widget has been created will @strong{not} be properly destructed when
+you call @code{widget-delete}.
 
 @node choice-item
-@section The @code{choice-item} Widget
+@subsection The @code{choice-item} Widget
 @findex choice-item@r{ widget}
 
 Syntax:
@@ -984,14 +1975,26 @@ choice-item
 @var{item} ::= (choice-item [@var{keyword} @var{argument}]... @var{value})
 @end example
 
+A widget to represent a choice in a @code{menu-choice} widget.  Its
+super is the @code{item} widget.
+
 The @var{value}, if present, is used to initialize the @code{:value}
-property.  The value should be a string, which will be inserted in the
-buffer as a button.  Activating the button of a @code{choice-item} is
-equivalent to activating the parent widget.  This widget will only match
-the specified value.
+property.
+
+It overrides the following properties:
+
+@table @code
+@item :action
+Activating the button of a @code{choice-item} is equivalent to
+activating the parent widget.
+
+@item :format
+By default, it buttonizes the tag (i.e., its value) and adds a newline
+character at the end of the widget.
+@end table
 
 @node toggle
-@section The @code{toggle} Widget
+@subsection The @code{toggle} Widget
 @findex toggle@r{ widget}
 
 Syntax:
@@ -1000,43 +2003,136 @@ toggle
 @var{type} ::= (toggle [@var{keyword} @var{argument}]...)
 @end example
 
+A widget that can toggle between two states.  Its super is the
+@code{item} widget.
+
 The widget has two possible states, @samp{on} and @samp{off}, which
 correspond to a @code{t} or @code{nil} value, respectively.
 
-The following extra properties are recognized:
+It either overrides or adds the following properties:
 
 @table @code
+@item :format
+By default, it buttonizes the value and adds a newline at the end of
+the widget.
+
 @item :on
 A string representing the @samp{on} state.  By default the string
 @samp{on}.
+
 @item :off
 A string representing the @samp{off} state.  By default the string
 @samp{off}.
+
 @vindex on-glyph@r{ keyword}
 @item :on-glyph
 Name of a glyph to be used instead of the @samp{:on} text string, on
 emacsen that supports this.
+
 @vindex off-glyph@r{ keyword}
 @item :off-glyph
 Name of a glyph to be used instead of the @samp{:off} text string, on
 emacsen that supports this.
+
+@item :value-create
+A function for creating the widget's value, according to its
+@samp{:on} or @samp{:off} state.
+
+@item :action
+Function to toggle the state of the widget.  After toggling, it
+notifies itself.
+
+@item :match
+This widget matches anything.
+@end table
+
+@node radio-button-toggle
+@subsection The @code{radio-button-toggle} Widget
+@findex radio-button-toggle@r{ widget}
+Syntax:
+
+@example
+@var{type} ::= (radio-button-toggle [@var{keyword} @var{argument}]...)
+@end example
+
+A toggle to use in the @code{radio} widget.
+
+It overrides the following properties:
+
+@table @code
+@item :button-prefix
+The empty string.
+
+@item :button-suffix
+The empty string.
+
+@item :on
+The string ``(*)'', to represent the @samp{on} state.
+
+@item :off
+The string ``( )'', to represent the @samp{off} state.
+
+@item :on-glyph
+The name of an image to represent the @samp{on} state.
+
+@item :off-glpyh
+The name of an image to represent the @samp{off} state.
+
+@item :format
+By default, it buttonizes its value.
+
+@item :notify
+A function to notify its parent.
 @end table
 
 @node checkbox
-@section The @code{checkbox} Widget
+@subsection The @code{checkbox} Widget
 @findex checkbox@r{ widget}
 
-This widget has two possible states, @samp{selected} and
-@samp{unselected}, which corresponds to a @code{t} or @code{nil} value.
-
 Syntax:
 
 @example
 @var{type} ::= (checkbox [@var{keyword} @var{argument}]...)
 @end example
 
+A widget to represent a toggle widget, with a checkbox.  Its super is
+the @code{toggle} widget.
+
+This widget has two possible states, @samp{selected} and
+@samp{unselected}, which corresponds to a @code{t} or @code{nil}
+value, respectively.
+
+It either overrides or adds the following properties:
+
+@table @code
+@item :button-prefix
+The empty string.
+
+@item :button-suffix
+The empty string.
+
+@item :format
+By default, buttonizes the value.
+
+@item :on
+By default, the string ``[X]''.
+
+@item :off
+By default, the string ``[ ]''.
+
+@item :on-glyph
+The name of the image to use when the state is @samp{on}.
+
+@item :off-glyph
+The name of the image to use when the state is @samp{off}.
+
+@item :action
+A function that toggles the checkbox, notifies the parents and in the
+@samp{on} state, activates its siblings.
+@end table
+
 @node checklist
-@section The @code{checklist} Widget
+@subsection The @code{checklist} Widget
 @findex checklist@r{ widget}
 
 Syntax:
@@ -1045,14 +2141,26 @@ checklist
 @var{type} ::= (checklist [@var{keyword} @var{argument}]...  @var{type} ... )
 @end example
 
+A widget to represent a multiplice choice.  Its super is the
+@code{default} widget.
+
 The @var{type} arguments represent each checklist item.  The widget's
 value will be a list containing the values of all checked @var{type}
-arguments.  The checklist widget will match a list whose elements all
-match at least one of the specified @var{type} arguments.
+arguments.
 
-The following extra properties are recognized:
+It either overrides or adds the following properties:
 
 @table @code
+@item :convert-widget
+As other composite widgets, a function that takes care of converting
+each checklist item.
+
+@item :copy
+A function to copy each checklist item.
+
+@item :format
+By default, it inserts its value.
+
 @vindex entry-format@r{ keyword}
 @item :entry-format
 This string will be inserted for each entry in the list.
@@ -1066,14 +2174,6 @@ checklist
 Insert a literal @samp{%}.
 @end table
 
-@vindex greedy@r{ keyword}
-@item :greedy
-Usually a checklist will only match if the items are in the exact
-sequence given in the specification.  By setting @code{:greedy} to
-non-@code{nil}, it will allow the items to come in any sequence.
-However, if you extract the value they will be in the sequence given
-in the checklist, i.e., the original sequence is forgotten.
-
 @vindex button-args@r{ keyword}
 @item :button-args
 A list of keywords to pass to the checkboxes.  Useful for setting,
@@ -1090,10 +2190,35 @@ checklist
 @vindex args@r{ keyword}
 @item :args
 The list of types.
+
+@item :value-create
+The function that takes care of inserting all values.
+
+@item :value-get
+A function that returns all values of selected items.
+
+@item :validate
+A function that ensures all selected children are valid.
+
+@item :match
+The checklist widget will match a list whose elements all
+match at least one of the specified @var{type} arguments.
+
+@item :match-inline
+Like the @code{:match} function, but taking into account the
+@code{:inline} property.
+
+@vindex greedy@r{ keyword}
+@item :greedy
+Usually a checklist will only match if the items are in the exact
+sequence given in the specification.  By setting @code{:greedy} to
+non-@code{nil}, it will allow the items to come in any sequence.
+However, if you extract the value they will be in the sequence given
+in the checklist, i.e., the original sequence is forgotten.
 @end table
 
 @node editable-list
-@section The @code{editable-list} Widget
+@subsection The @code{editable-list} Widget
 @findex editable-list@r{ widget}
 
 Syntax:
@@ -1102,12 +2227,19 @@ editable-list
 @var{type} ::= (editable-list [@var{keyword} @var{argument}]... @var{type})
 @end example
 
-The value is a list, where each member represents one widget of type
-@var{type}.
+A widget that can hold a variable list of widgets of the same type,
+represented by @var{type}.  Its super is the @code{default} widget.
 
-The following extra properties are recognized:
+It either overrides or adds the following properties:
 
 @table @code
+@item :convert-widget
+As other composite widgets, a function that takes care of converting
+each type in @var{type}.
+
+@item :copy
+A function to copy the types given in @var{type}.
+
 @vindex entry-format@r{ keyword}
 @item :entry-format
 This string will be inserted for each entry in the list.
@@ -1117,9 +2249,9 @@ editable-list
 This will be replaced with the buffer representation of the @var{type}
 widget.
 @item %i
-Insert the @b{[INS]} button.
+Insert the @b{[INS]} button, a widget of type @code{insert-button}.
 @item %d
-Insert the @b{[DEL]} button.
+Insert the @b{[DEL]} button, a widget of type @code{delete-button}.
 @item %%
 Insert a literal @samp{%}.
 @end table
@@ -1140,6 +2272,18 @@ editable-list
 @item :buttons
 The widgets representing the insert and delete buttons.
 
+@item :format
+By default, insert its value and at the and adds an insert button.
+
+This is useful so that new elements can be added to the list upon user
+request.
+
+@item :format-handler
+A function that recognize the escape for inserting an insert button.
+
+@item :offset
+By default, this widget has an offset of 12.
+
 @vindex children@r{ keyword}
 @item :children
 The widgets representing the elements of the list.
@@ -1147,24 +2291,124 @@ editable-list
 @vindex args@r{ keyword}
 @item :args
 List whose @sc{car} is the type of the list elements.
+
+@item :insert-before
+Function to insert a new widget as a child of the @code{editable-list}
+widget.
+
+This function inserts a recently deleted child, if there is one.  That
+is useful, so that the user can move elements in a list easily.  If
+there is not a recently deleted child, it inserts a child with its
+default value.
+
+@item :delete-at
+Function to delete a child from the widget, and store it into the
+@code{:last-deleted} list, so that it can be reinserted when the
+@code{:insert-before} function executes.
+
+@item :value-create
+The function that takes care of inserting all values.
+
+@item :value-get
+Function that returns a list with the value of the child widgets.
+
+@item :validate
+This widget validates if all children validate.
+
+@item :match
+To match, the value must be a list and all the list members must match
+the specified @var{type}.
+
+@item :match-inline
+Like the @code{:match} function, but taking into account inline
+values and widgets.
 @end table
 
 @node group
-@section The @code{group} Widget
+@subsection The @code{group} Widget
 @findex group@r{ widget}
 
-This widget simply group other widgets together.
-
 Syntax:
 
 @example
 @var{type} ::= (group [@var{keyword} @var{argument}]... @var{type}...)
 @end example
 
-The value is a list, with one member for each @var{type}.
+A widget to group other widgets.  Its super is the @code{default}
+widget.
+
+Its value is a list, with one member for each @var{type}.
+
+It overrides the following properties:
+
+@table @code
+@item :convert-widget
+As other composite widgets, a function that takes care of converting
+each widget in @var{type}.
+
+@item :copy
+A function to copy the types given in @var{type}.
+
+@item :format
+By default, displays a newline character and its value.
+
+@item :value-create
+A function to create each of its components.
+
+@item :value-get
+The same function used by the @code{editable-list} widget.
+
+@item :default-get
+A function that returns a list whose members are the default values of
+each widget it groups.
+
+@item :validate
+This widget validates if all of its children validate.
+
+@item :match
+This widget matches a value that matches each of its components.
+
+@item :match-inline
+As @code{:match}, but taking into account widgets and values that are
+inline.
+@end table
+
+@node documentation-string
+@subsection The @code{documentation-string} Widget
+@findex documentation-string@r{ widget}
+Syntax:
+
+@example
+@var{type} ::= (documentation-string [@var{keyword} @var{argument}]... @var{value})
+@end example
+
+A widget to represent a documentation string.  Its super is the
+@code{item} widget.
+
+It either overrides or adds the following properties:
+
+@table @code
+@item :format
+By default, insert its value.
+
+@item :value-create
+Function to insert a documentation string, possibly hiding part of the
+documentation if its large.
+
+To show or hide the rest of the documentation, uses a
+@code{visibility} widget.
+
+@item :action
+Function to toggle showing the documentation upon an event.
+
+@item :visibility-widget
+A symbol, the type of the widget to use for the visibility widget.
+
+This is, by default, the symbol @code{visibility}.
+@end table
 
 @node Sexp Types
-@chapter Sexp Types
+@section Sexp Types
 @cindex sexp types
 
 A number of widgets for editing @dfn{s-expressions} (Lisp types), sexp
@@ -1179,7 +2423,7 @@ Sexp Types
 @end menu
 
 @node constants
-@section The Constant Widgets
+@subsection The Constant Widgets
 @cindex constant widgets
 
 The @code{const} widget can contain any Lisp expression, but the user is
@@ -1192,19 +2436,26 @@ constants
 @var{type} ::= (const [@var{keyword} @var{argument}]...  [ @var{value} ])
 @end example
 
-The @var{value}, if present, is used to initialize the @code{:value}
-property and can be any s-expression.
+Its super is the @code{item} widget.  The @var{value}, if present, is
+used to initialize the @code{:value} property and can be any
+s-expression.
 
 @deffn Widget const
 This will display any valid s-expression in an immutable part of the
 buffer.
+
+It overrides the @code{:prompt-value} function, to avoid prompting and
+just return the widget's value.
 @end deffn
 
 There are two variations of the @code{const} widget, namely
 @code{variable-item} and @code{function-item}.  These should contain a
-symbol with a variable or function binding.  The major difference from
-the @code{const} widget is that they will allow the user to see the
-variable or function documentation for the symbol.
+symbol with a variable or function binding, respectively.  The major
+difference from the @code{const} widget is that they will allow the
+user to see the variable or function documentation for the symbol.
+
+This is accomplished via using the @samp{%h} format escape, and adding
+an appropiate @code{:documentation-property} function for each widget.
 
 @deffn Widget variable-item
 An immutable symbol that is bound as a variable.
@@ -1215,7 +2466,7 @@ constants
 @end deffn
 
 @node generic
-@section Generic Sexp Widget
+@subsection Generic Sexp Widget
 @cindex generic sexp widget
 
 The @code{sexp} widget can contain any Lisp expression, and allows the
@@ -1228,23 +2479,42 @@ generic
 @end example
 
 @deffn Widget sexp
-This will allow you to edit any valid s-expression in an editable buffer
-field.
+This widget represents an editable field that's useful to edit any
+valid s-expression.
 
 The @code{sexp} widget takes the same keyword arguments as the
 @code{editable-field} widget.  @xref{editable-field}.
+
+Its default value is @code{nil}.
+@end deffn
+
+@deffn Widget restricted-sexp
+A widget to edit Lisp expressions restricted to certain values or
+types.  Its super is the @code{sexp} widget.
+
+It works just like the sexp widget, but it overrides the @code{:match}
+function to match for certain values.  To use this widget, either you
+must define a @code{:match} function or give a
+@code{:match-alternatives} property.  The @code{:match-alternatives}
+property holds a list of predicate functions to call when checking if
+a given value matches the widget.  Each predicate function will be
+called with one argument, the value to be matched, and should return
+non-@code{nil} on success.
+
+As an example, the @code{integer} widget overrides
+@code{:match-alternatives} to @code{(integerp)}.
 @end deffn
 
 @node atoms
-@section Atomic Sexp Widgets
+@subsection Atomic Sexp Widgets
 @cindex atomic sexp widget
 
 The atoms are s-expressions that do not consist of other s-expressions.
 For example, a string, a file name, or a symbol are atoms, while a list
 is a composite type.  You can edit the value of an atom with the
-following widgets.
+widgets described in this section.
 
-The syntax for all the atoms are:
+The syntax for all the atoms is:
 
 @example
 @var{type} ::= (@var{construct} [@var{keyword} @var{argument}]...  [ @var{value} ])
@@ -1252,68 +2522,151 @@ atoms
 
 The @var{value}, if present, is used to initialize the @code{:value}
 property and must be an expression of the same type as the widget.
-That is, the string widget can only be initialized with a string.
+That is, for example, the string widget can only be initialized with a
+string.
 
 All the atom widgets take the same keyword arguments as the
 @code{editable-field} widget.  @xref{editable-field}.
 
 @deffn Widget string
-Allows you to edit a string in an editable field.
+An editable field widget that can represent any Lisp string.
+
+It offers completion via the ispell library and the @code{:complete}
+property.
 @end deffn
 
 @deffn Widget regexp
-Allows you to edit a regular expression in an editable field.
+An editable field widget that can represent a regular expression.
+
+Overrides the @code{:match} and the @code{:validate} properties to
+check that the value is a valid regexp.
 @end deffn
 
 @deffn Widget character
-Allows you to enter a character in an editable field.
+An editable field widget that can represent a character.
+
+The character widget represents some characters (like the newline
+character) in a special manner, to make it easier for the user to see
+what's the content of the character field.
 @end deffn
 
 @deffn Widget file
-Allows you to edit a file name in an editable field.
+A widget for editing file names.
 
 Keywords:
 @table @code
+@item :completions
+Offers file name completion to the user.
+
+@item :prompt-value
+A function to read a file name from the minibuffer.
+
 @vindex must-match@r{ keyword}
 @item :must-match
-If this is set to non-@code{nil}, only existing file names will be
-allowed in the minibuffer.
+If this is set to non-@code{nil}, only existing file names are allowed
+when prompting for a value in the minibuffer.
+
+@item :match
+The widget matches if the value is a string, and the file whose name
+is that string is an existing file, or if @code{:must-match} is
+@code{nil}.
+
+@item :validate
+The widget is valid if its value matches.
+
 @end table
 @end deffn
 
 @deffn Widget directory
-Allows you to edit a directory name in an editable field.
-Similar to the @code{file} widget.
+A widget for editing directory names.
+
+Its super is the @code{file} widget, and it overrides the
+@code{:completions} property, to offer completions only for
+directories.
 @end deffn
 
 @deffn Widget symbol
-Allows you to edit a Lisp symbol in an editable field.
+A widget for editing a Lisp symbol.
+
+Its value by default is @code{nil}.
 @end deffn
 
 @deffn Widget function
-Allows you to edit a lambda expression, or a function name with completion.
+A widget for editing a lambda expression, or a function name, offering
+completion.  Its super is the @code{restricted-sexp} widget.
 @end deffn
 
 @deffn Widget variable
-Allows you to edit a variable name, with completion.
+A widget for editing variable names, offering completion.  Its super
+is the @code{symbol} widget.
 @end deffn
 
 @deffn Widget integer
-Allows you to edit an integer in an editable field.
+A widget for editing integers in an editable field.  Its super is the
+@code{restricted-sexp} widget.
+
+It has a default @code{:value} of 0.
+@end deffn
+
+@deffn Widget natnum
+A widget for editing non-negative integers.  Its super is the
+@code{restricted-sexp} widget.
+
+It has a default @code{:value} of 0.
+@end deffn
+
+@deffn Widget float
+A widget for editing a floating point number.  Its super is the
+@code{restricted-sexp} widget.
+
+It has a default @code{:value} of 0.0.
 @end deffn
 
 @deffn Widget number
-Allows you to edit a number in an editable field.
+A widget for editing a number, either floating point or integer.  Its
+super is the @code{restricted-sexp} widget.
+
+It has a default @code{:value} of 0.0.
 @end deffn
 
 @deffn Widget boolean
-Allows you to edit a boolean.  In Lisp this means a variable which is
-either @code{nil} meaning false, or non-@code{nil} meaning true.
+A widget for editing a boolean value.  Its super is the @code{toggle}
+widget.
+
+Its value may be @code{nil}, meaning false, or non-@code{nil}, meaning
+true.
+@end deffn
+
+@deffn Widget color
+A widget to edit a color name.
+
+In addition, shows a sample that shows the selected color, if any.
 @end deffn
 
+@deffn Widget other
+A widget useful as the last item in a @code{choice} widget, since it
+matches any value.
+
+Its super is the @code{sexp} widget, and its @code{:value} is
+@code{other}, by default.
+@end deffn
+
+@deffn Widget coding-system
+A widget that can represent a coding system name, offering
+completions.  @xref{Coding Systems,,,elisp, the Emacs Lisp Reference
+Manual}.  Its super is the @code{symbol} widget.
+
+It has a default value of @code{undecided}.
+@end deffn
+
+@deffn Widget key
+A widget to represent a key sequence.
+
+It uses a special keymap as the @code{:keymap}.
+@end deffn
 
 @node composite
-@section Composite Sexp Widgets
+@subsection Composite Sexp Widgets
 @cindex composite sexp widgets
 
 The syntax for the composite widget construct is:
@@ -1327,6 +2680,9 @@ composite
 will be displayed in the buffer, and will be editable by the user.
 
 @deffn Widget cons
+A widget to edit cons-cell values.  Its super is the @code{group}
+widget.
+
 The value of a @code{cons} widget must be a cons-cell whose @sc{car}
 and @sc{cdr} have two specified types.  It uses this syntax:
 
@@ -1336,8 +2692,10 @@ composite
 @end deffn
 
 @deffn Widget choice
-The value matched by a @code{choice} widget must have one of a fixed
-set of types.  The widget's syntax is as follows:
+A widget to hold a value of one of a fixed set of types.  Its super is
+the @code{menu-choice} widget.
+
+The widget's syntax is as follows:
 
 @example
 @var{type} ::= (choice [@var{keyword} @var{argument}]...  @var{type} ... )
@@ -1345,9 +2703,19 @@ composite
 
 The value of a @code{choice} widget can be anything that matches any of the
 @var{types}.
+
+This widget only displays the widget that corresponds to the current
+choice.
+@end deffn
+
+@deffn Widget radio
+A widget to hold a value of one of a fixed set of options.  Its super is
+the @code{radio-button-choice} widget.
 @end deffn
 
 @deffn Widget list
+A widget to edit a list value.  Its super is the @code{group} widget.
+
 The value of a @code{list} widget must be a list whose element types
 match the specified component types:
 
@@ -1355,15 +2723,18 @@ composite
 @var{type} ::= (list [@var{keyword} @var{argument}]...  @var{component-type}...)
 @end example
 
-Thus, @code{(list string number)} matches lists of two elements,
-the first being a string and the second being a number.
+Thus, for example, @code{(list string number)} matches lists of two
+elements, the first being a string and the second being a number.
 @end deffn
 
 @deffn Widget vector
+A widget to edit a vector value.  Its super is the @code{group}
+widget.
+
 The @code{vector} widget is like the @code{list} widget but matches
-vectors instead of lists.  Thus, @code{(vector string number)} matches
-vectors of two elements, the first being a string and the second being
-a number.
+vectors instead of lists.  Thus, for example, @code{(vector string
+number)} matches vectors of two elements, the first being a string and
+the second being a number.
 @end deffn
 
 The above suffice for specifying fixed size lists and vectors.  To get
@@ -1392,126 +2763,74 @@ composite
 trying to explain it here, I'll just suggest you meditate over it for
 a while.
 
-@deffn Widget set
-Specifies a type whose values are the lists whose elements all belong
-to a given set.  The order of elements of the list is not significant.
-Here's the syntax:
-
-@example
-@var{type} ::= (set [@var{keyword} @var{argument}]...  @var{permitted-element} ... )
-@end example
-
-Use @code{const} to specify each permitted element, like this:
-@code{(set (const a) (const b))}.
-@end deffn
-
-@deffn Widget repeat
-Specifies a list of any number of elements that fit a certain type.
-
-@example
-@var{type} ::= (repeat [@var{keyword} @var{argument}]...  @var{type})
-@end example
-@end deffn
-
-@node Widget Properties
-@chapter Properties
-@cindex properties of widgets
-@cindex widget properties
-
-You can examine or set the value of a widget by using the widget object
-that was returned by @code{widget-create}.
-
-@defun widget-value widget
-Return the current value contained in @var{widget}.
-It is an error to call this function on an uninitialized widget.
-@end defun
-
-@defun widget-value-set widget value
-Set the value contained in @var{widget} to @var{value}.
-It is an error to call this function with an invalid @var{value}.
-@end defun
-
-@strong{Important:} You @emph{must} call @code{widget-setup} after
-modifying the value of a widget before the user is allowed to edit the
-widget again.  It is enough to call @code{widget-setup} once if you
-modify multiple widgets.  This is currently only necessary if the widget
-contains an editing field, but may be necessary for other widgets in the
-future.
+@deffn Widget set
+A widget to hold a list of members from a fixed set.  Its super is the
+@code{checklist} widget.
 
-If your application needs to associate some information with the widget
-objects, for example a reference to the item being edited, it can be
-done with @code{widget-put} and @code{widget-get}.  The property names
-must begin with a @samp{:}.
+Its value is a list where the elements all belong to a given set.  The
+order of elements of the list is not significant.
 
-@defun widget-put widget property value
-In @var{widget} set @var{property} to @var{value}.
-@var{property} should be a symbol, while @var{value} can be anything.
-@end defun
+Here's the syntax:
 
-@defun widget-get widget property
-In @var{widget} return the value for @var{property}.
-@var{property} should be a symbol, the value is what was last set by
-@code{widget-put} for @var{property}.
-@end defun
+@example
+@var{type} ::= (set [@var{keyword} @var{argument}]...  @var{permitted-element} ... )
+@end example
 
-@defun widget-member widget property
-Non-@code{nil} if @var{widget} has a value (even @code{nil}) for
-property @var{property}.
-@end defun
+Use @code{const} to specify each permitted element, like this:
+@code{(set (const a) (const b))}.
+@end deffn
 
-@defun widget-apply widget property &rest args
-Apply the value of @var{property} to @var{widget}, passing @var{args}
-as additional arguments to the function.  Return the result of that
-function call.
-@end defun
+@deffn Widget repeat
+Specifies a list of any number of elements that fit a certain type.
+Its super is the @code{editable-list} widget.
 
-Occasionally it can be useful to know which kind of widget you have,
-i.e., the name of the widget type you gave when the widget was created.
+@example
+@var{type} ::= (repeat [@var{keyword} @var{argument}]...  @var{type})
+@end example
+@end deffn
 
-@defun widget-type widget
-Return the name of @var{widget}, a symbol.
-@end defun
+@deffn Widget plist
+A widget to edit property lists.  Its super is the @code{list} widget.
 
-@cindex active widget
-@cindex inactive widget
-@cindex activate a widget
-@cindex deactivate a widget
-Widgets can be in two states: active, which means they are modifiable by
-the user, or inactive, which means they cannot be modified by the user.
-You can query or set the state with the following code:
+It recognizes the following properties:
 
-@lisp
-;; Examine if @var{widget} is active or not.
-(if (widget-apply @var{widget} :active)
-    (message "Widget is active.")
-  (message "Widget is inactive.")
+@table @code
+@item :options
+A given set of recommended key-value values for the @code{plist}
+widget.  Each option shows up as a checklist item.
 
-;; Make @var{widget} inactive.
-(widget-apply @var{widget} :deactivate)
+@item :key-type
+The widget type to use for the plist keys.  By default, it uses the
+@code{symbol} widget.
 
-;; Make @var{widget} active.
-(widget-apply @var{widget} :activate)
-@end lisp
+@item :value-type
+The widget type to use for the plist values.  By default, it uses the
+@code{sexp} widget.
+@end table
+@end deffn
 
-A widget is inactive if it, or any of its ancestors (found by
-following the @code{:parent} link), have been deactivated.  To make sure
-a widget is really active, you must therefore activate both it and
-all its ancestors.
+@deffn Widget alist
+A widget to edit association lists.  Its super is the @code{list}
+widget.
 
-@lisp
-(while widget
-  (widget-apply widget :activate)
-  (setq widget (widget-get widget :parent)))
-@end lisp
+It recognizes the same properties that the @code{plist} widget, with
+the difference that the @code{:key-type} uses by default a @code{sexp}
+widget.
+@end deffn
 
-You can check if a widget has been made inactive by examining the value
-of the @code{:inactive} keyword.  If this is non-@code{nil}, the widget itself
-has been deactivated.  This is different from using the @code{:active}
-keyword, in that the latter tells you if the widget @strong{or} any of
-its ancestors have been deactivated.  Do not attempt to set the
-@code{:inactive} keyword directly.  Use the @code{:activate}
-@code{:deactivate} keywords instead.
+Most composite widgets do not allow for recursion.  That is, none of
+the contained widgets may be of the same type that is currently being
+defined.  To allow for this kind of widgets, there's the @code{lazy}
+widget.
+
+@deffn Widget lazy
+A base widget for recursive data structures.  Its super is the
+@code{default} widget.
 
+When instantiated, it contains a single inferior widget of the widget
+type specified in the @code{:type} property.  Its value is the same as
+the value of this inferior widget.
+@end deffn
 
 @node Defining New Widgets
 @chapter Defining New Widgets
@@ -1520,19 +2839,27 @@ Defining New Widgets
 
 You can define specialized widgets with @code{define-widget}.  It allows
 you to create a shorthand for more complex widgets, including specifying
-component widgets and new default values for the keyword
-arguments.
+component widgets and new default values for the keyword arguments.
 
 @defun define-widget name class doc &rest args
-Define a new widget type named @var{name} from @code{class}.
+Define a new widget type named @var{name} that derives from @var{class}.
 
-@var{name} and class should both be symbols, @code{class} should be one
-of the existing widget types.
+@var{name} and @var{class} should both be symbols, and @var{class}
+should be one of the existing widget types.
 
 The third argument @var{doc} is a documentation string for the widget.
 
-After the new widget has been defined, the following two calls will
-create identical widgets:
+@var{args} should be key-value pairs, overriding keyword values of
+@var{class}, or adding new recognized keywords for @var{name}.
+
+Usually, you'll want to derive from an existing widget type, like the
+@code{editable-field} widget, or the @code{default} widget, but it's
+also possible to derive from nothing, by passing a value of @code{nil}
+as @var{class}.  Note that if you do this, you're entirely responsible
+for defining a whole new default behavior for your widgets.
+
+After using this function, the following two calls will create
+identical widgets:
 
 @itemize @bullet
 @item
@@ -1555,170 +2882,67 @@ Defining New Widgets
 If you only want to specify defaults for keywords with no complex
 conversions, you can use @code{identity} as your conversion function.
 
-The following additional keyword arguments are useful when defining new
-widgets:
+When defining new widgets, the @code{:convert-widget} property might
+be useful:
+
 @table @code
 @vindex convert-widget@r{ keyword}
 @item :convert-widget
 Function to convert a widget type before creating a widget of that
-type.  It takes a widget type as an argument, and returns the converted
-widget type.  When a widget is created, this function is called for the
-widget type and all the widget's parent types, most derived first.
-
-The following predefined functions can be used here:
-
-@defun widget-types-convert-widget widget
-Convert @code{:args} as widget types in @var{widget}.
-@end defun
-
-@defun widget-value-convert-widget widget
-Initialize @code{:value} from @code{:args} in @var{widget}.
-@end defun
-
-@vindex copy@r{ keyword}
-@item :copy
-Function to deep copy a widget type.  It takes a shallow copy of the
-widget type as an argument (made by @code{copy-sequence}), and returns a
-deep copy.  The purpose of this is to avoid having different instances
-of combined widgets share nested attributes.
-
-The following predefined functions can be used here:
-
-@defun widget-types-copy widget
-Copy @code{:args} as widget types in @var{widget}.
-@end defun
-
-@vindex value-to-internal@r{ keyword}
-@item :value-to-internal
-Function to convert the value to the internal format.  The function
-takes two arguments, a widget and an external value, and returns the
-internal value.  The function is called on the present @code{:value}
-when the widget is created, and on any value set later with
-@code{widget-value-set}.
-
-@vindex value-to-external@r{ keyword}
-@item :value-to-external
-Function to convert the value to the external format.  The function
-takes two arguments, a widget and an internal value, and returns the
-external value.
-
-@vindex create@r{ keyword}
-@item :create
-Function to create a widget from scratch.  The function takes one
-argument, a widget type, and creates a widget of that type, inserts it
-in the buffer, and returns a widget object.
-
-@vindex delete@r{ keyword}
-@item :delete
-Function to delete a widget.  The function takes one argument, a widget,
-and should remove all traces of the widget from the buffer.
-
-The default value is:
-
-@defun widget-default-delete widget
-Remove @var{widget} from the buffer.
-Delete all @code{:children} and @code{:buttons} in @var{widget}.
-@end defun
-
-In most cases you should not change this value, but instead use
-@code{:value-delete} to make any additional cleanup.
-
-@vindex value-create@r{ keyword}
-@item :value-create
-Function to expand the @samp{%v} escape in the format string.  It will
-be called with the widget as its argument and should insert a
-representation of the widget's value in the buffer.
-
-Nested widgets should be listed in @code{:children} or @code{:buttons}
-to make sure they are automatically deleted.
-
-@vindex value-delete@r{ keyword}
-@item :value-delete
-Should remove the representation of the widget's value from the buffer.
-It will be called with the widget as its argument.  It doesn't have to
-remove the text, but it should release markers and delete nested widgets
-if these are not listed in @code{:children} or @code{:buttons}.
-
-@vindex value-get@r{ keyword}
-@item :value-get
-Function to extract the value of a widget, as it is displayed in the
-buffer.
-
-The following predefined function can be used here:
-
-@defun widget-value-value-get widget
-Return the @code{:value} property of @var{widget}.
-@end defun
-
-@vindex format-handler@r{ keyword}
-@item :format-handler
-Function to handle unknown @samp{%} escapes in the format string.  It
-will be called with the widget and the character that follows the
-@samp{%} as arguments.  You can set this to allow your widget to handle
-non-standard escapes.
-
-@findex widget-default-format-handler
-You should end up calling @code{widget-default-format-handler} to handle
-unknown escape sequences, which will handle the @samp{%h} and any future
-escape sequences, as well as give an error for unknown escapes.
-
-@vindex action@r{ keyword}
-@item :action
-Function to handle user initiated events.  By default, @code{:notify}
-the parent.
+type.
 
-The following predefined function can be used here:
-
-@defun widget-parent-action widget &optional event
-Tell @code{:parent} of @var{widget} to handle the @code{:action}.
-Optional @var{event} is the event that triggered the action.
-@end defun
+It takes a widget type as an argument, and returns the converted
+widget type.  When a widget is created, this function is called for
+the widget type and all the widget's parent types, most derived first.
 
-@vindex prompt-value@r{ keyword}
-@item :prompt-value
-Function to prompt for a value in the minibuffer.  The function should
-take four arguments, @var{widget}, @var{prompt}, @var{value}, and
-@var{unbound} and should return a value for widget entered by the user.
-@var{prompt} is the prompt to use.  @var{value} is the default value to
-use, unless @var{unbound} is non-@code{nil}, in which case there is no default
-value.  The function should read the value using the method most natural
-for this widget, and does not have to check that it matches.
+The predefined functions @code{widget-types-convert-widget} and
+@code{widget-value-convert-widget} can be used here.
 @end table
 
-If you want to define a new widget from scratch, use the @code{default}
-widget as its base.
-
-@deffn Widget default
-Widget used as a base for other widgets.
-
-It provides most of the functionality that is referred to as ``by
-default'' in this text.
-@end deffn
-
-@node Widget Browser
-@chapter Widget Browser
+@node Inspecting Widgets
+@chapter Inspecting Widgets
 @cindex widget browser
 
-There is a separate package to browse widgets.  This is intended to help
-programmers who want to examine the content of a widget.  The browser
-shows the value of each keyword, but uses links for certain keywords
-such as @samp{:parent}, which avoids printing cyclic structures.
+There is a separate package to browse widgets, in
+@samp{wid-browse.el}.  This is intended to help programmers who want
+to examine the content of a widget.  The browser shows the value of
+each keyword, but uses links for certain keywords such as
+@samp{:parent}, which avoids printing cyclic structures.
 
 @deffn Command widget-browse @var{widget}
 Create a widget browser for @var{widget}.
+
 When called interactively, prompt for @var{widget}.
 @end deffn
 
 @deffn Command widget-browse-other-window @var{widget}
 Create a widget browser for @var{widget} and show it in another window.
+
 When called interactively, prompt for @var{widget}.
 @end deffn
 
 @deffn Command widget-browse-at @var{pos}
 Create a widget browser for the widget at @var{pos}.
+
 When called interactively, use the position of point.
 @end deffn
 
+In addition, there's a function to describe the widget at point.
+
+@deffn Command widget-describe &optional widget-or-pos
+Describe the widget at point.
+
+When called from Lisp, @var{widget-or-pos} might be the widget to
+describe or a buffer position where a widget is present.  If
+@var{widget-or-pos} is @code{nil}, the widget to describe is the
+widget at point.
+
+This command sets up a help buffer for providing information about the
+widget, mainly its @code{:action} and @code{:mouse-down-action}
+functions, and provides links to describe it in more detail using the
+@code{widget-browse} commands described above.
+@end deffn
+
 @node  Widget Minor Mode
 @chapter Widget Minor Mode
 @cindex widget minor mode
@@ -1740,14 +2964,24 @@ Utilities
 @chapter Utilities
 @cindex utility functions for widgets
 
+Here we describe some utility functions that don't really have a place
+earlier in this manual.
+
 @defun widget-prompt-value widget prompt [ value unbound ]
 Prompt for a value matching @var{widget}, using @var{prompt}.
 The current value is assumed to be @var{value}, unless @var{unbound} is
 non-@code{nil}.
+
+Converts @var{widget} before prompting, and for prompting it uses the
+@code{:prompt-value} function.  This function returns the user
+``answer'', and it's an error if that answer doesn't match the widget,
+as with the @code{:match} function.
+
+If the answer matches the widget, returns the answer.
 @end defun
 
 @defun widget-get-sibling widget
-Get the item which @var{widget} is assumed to toggle.
+Get the item which @var{widget} should toggle.
 This is only meaningful for radio buttons or checkboxes in a list.
 @end defun
 
@@ -1773,6 +3007,142 @@ Utilities
 then the return value is the @var{value} of the chosen element.
 @end defun
 
+@defun widget-image-find image
+Create a graphical button from @var{image}, an image or a file name
+sans extension.
+
+If @var{image} is a file name, the file should be in
+@code{widget-image-directory}, or in a place where @code{find-image}
+will find it.
+@end defun
+
+@defun widget-image-insert widget tag image
+As part of @var{widget}, insert the text @var{tag} or, if supported,
+the image @var{image}.
+
+@var{image} should be as described in @code{widget-image-find}.
+@end defun
+
+@defun widget-echo-help pos
+Display help-echo text for the widget at @var{pos}.
+
+Uses the value of @code{:help-echo}.  If it is a function, it calls it
+to get a string.  Otherwise, it @code{eval}s it.
+@end defun
+
+@node  Customization
+@chapter Customization
+This chapter is about the customization options for the Widget
+library, for the end user.
+
+@deffn Face widget-field-face
+Face used for other editing fields.
+@end deffn
+
+@deffn Face widget-button-face
+Face used for buttons.
+@end deffn
+
+@defopt widget-mouse-face
+Face used for highlighting a button when the mouse pointer moves
+across it.
+
+The default value is @code{highlight}.
+@end defopt
+
+@defopt widget-image-directory
+Directory where Widget should look for images.
+
+Widget will look here for a file with the same name as specified for the
+image, with either a @file{.xpm} (if supported) or @file{.xbm} extension.
+@end defopt
+
+@defopt widget-image-enable
+If non-@code{nil}, allow images to appear on displays where they are supported.
+@end defopt
+
+@defopt widget-image-conversion
+An alist to convert symbols from image formats to file name suffixes.
+
+Each element is a cons cell (@var{format} . @var{suffix}), where
+@var{format} is a symbol that represents an image format and
+@var{suffix} is its correspondent suffix.
+@end defopt
+
+@defopt widget-button-prefix
+String to prefix buttons.
+@end defopt
+
+@defopt widget-button-suffix
+String to suffix buttons.
+@end defopt
+
+@defopt widget-push-button-prefix
+String to prefix push buttons.
+@end defopt
+
+@defopt widget-push-button-suffix
+String to suffix push buttons.
+@end defopt
+
+@defopt widget-link-prefix
+String to prefix links.
+@end defopt
+
+@defopt widget-link-suffix
+String to suffix links.
+@end defopt
+
+@defopt widget-choice-toggle
+If non-@code{nil}, toggle when there are just two options.
+
+By default, its value is @code{nil}.
+@end defopt
+
+@defopt widget-documentation-links
+If non-@code{nil}, add hyperlinks to documentation strings.
+@end defopt
+
+@defopt widget-documentation-link-regexp
+A regexp that matches potential links in documentation strings.  The
+link itself should match to the first group.
+@end defopt
+
+@defopt widget-documentation-link-p
+A predicate function to test if a string is useful as a link.  The
+function is called with one argument, a string, and should return
+non-@code{nil} if there should be a link for that string.
+
+By default, the value is @code{intern-soft}.
+@end defopt
+
+@defopt widget-documentation-link-type
+A symbol that represents a widget type to use for links in
+documentation strings.
+
+By default, the value is @code{documentation-link}.
+@end defopt
+
+@defopt widget-menu-max-size
+Maximum size for a popup menu.  By default, its value is 40.
+
+If a function ask you to choose from a menu that is larger than this
+value, it will use the minibuffer.
+@end defopt
+
+@defopt widget-menu-max-shortcuts
+Largest number of items for which it works to choose one with a
+character.
+
+For a larger number, use the minibuffer.
+@end defopt
+
+@defopt widget-menu-minibuffer-flag
+Whether to use the minibuffer to ask for a choice.
+
+If @code{nil}, the default, read a single character.
+@end defopt
+
 @node  Widget Wishlist
 @chapter Wishlist
 @cindex todo
@@ -1808,15 +3178,6 @@ Widget Wishlist
 @item
 Find a way to make glyphs look inactive.
 
-@item
-Add @code{property-list} widget.
-
-@item
-Add @code{association-list} widget.
-
-@item
-Add @code{key-binding} widget.
-
 @item
 Add @code{widget} widget for editing widget specifications.
 
-- 
2.34.1

Re: Editions to the Widget Manual

[Eli Zaretskii]

> Date: Sat, 2 Sep 2023 08:14:53 -0300
> Cc: emacs-devel@gnu.org, drew.adams@oracle.com, bovine@cyberscientist.ca
> From: Mauro Aranda <maurooaranda@gmail.com>
> 
> On 2/9/23 07:26, Eli Zaretskii wrote:
>  >> Date: Sat, 2 Sep 2023 07:15:20 -0300
>  >> Cc: emacs-devel@gnu.org, drew.adams@oracle.com, bovine@cyberscientist.ca
>  >> From: Mauro Aranda <maurooaranda@gmail.com>
>  >>
>  >> On 2/9/23 04:25, Eli Zaretskii wrote:
>  >>  > Do you think the version you have is good enough to install, perhaps
>  >>  > even on the emacs-29 release branch?
>  >>
>  >> I think is good enough, yes.  But I based the changes on what's on
>  >> master, so I'll have to check if some text needs to be different for the
>  >> release branch.
>  >>
>  >> I'll send the patch as soon as I do that.
>  >
>  > Thanks.
> 
> Thanks to you for taking a look at this, really.  I'm just happy to be
> able to contribute something back to Emacs.
> 
> As for the changes, I didn't need to adapt anything for the emacs-29
> branch.  I attach a patch against it, in which I also incorporated the
> change suggested by Yuan Fu of moving the default widget to its own
> subsection.  My next step would be to come up with short examples
> demonstrating how to use the more important widgets and functions.
> Hopefully it doesn't take me too long.

Thanks, I installed this on the emacs-29 branch.