Re: Customizing fontsets

[Kenichi Handa <handa@m17n.org>]

In article <87llxqorkr.fsf@gnu.org>, Alex Schroeder <alex@gnu.org> writes:
> Oliver Scholz <alkibiades@gmx.de> writes:
>>  But wouldn't it be an option to add a `custom-set-fontsets' besides
>>  `custom-set-faces' and `custom-set-variables'? 
>>  In fact I started to work on it.

> I am happy to see somebody work on it!

Me too!!!

>>  Currently I wonder what the default values should be that a
>>  "fontset-widget" should present to the user. The return-value of
>>  `fontset-info' is simply to large, I think. It seems weird that a user
>>  should specify a fontset covering two or three charsets in her .emacs
>>  or in .Xresources -- and is confronted with a list of dozens of
>>  charsets then, when she wants to customize it later.

> I don't understand.  When you run M-x customize-fontset RET
> fontset-default RET, you expect to see a widget that explains the
> value of "fontset-default", and offer a way to change it.  Thus, all
> the info returned by (fontset-info "fontset-default") must be visible
> and editable at some point.

But, it is true that the value of fontset-info is very hard
to customize.  A fontset is created by new-fontset, and is
modified by the sequence of set-fontset-font.  In the
resulting fontset, the specified data are scattered around
in the char-table of the fontset.

I think the following idea will solve this problem.

The arguemnt FONTLIST of new-fontset is a list of this form:
    ((TARGET . FONT-SPEC) ...)
TARGET is a character, a cons (FROM-CHAR . TO-CHAR), or a
charset.  FONT-SPEC is (FAMILY . REGISTRY) or FONT-NAME.

The function set-fontset-font also takes the arguments
TARGET and FONT-SPEC.

In other words, a fontset can be re-created by the sequence
of (TARGET . FONT-SPEC).  So how about recording that
sequence as a list in each fontset (the order is important).
I think it's far user-friendly to customize that list than
to customize char-table elements.  In addition, we can use
the normal customization facility for a list (INS, DEL) at
the top level.

---
Ken'ichi HANDA
handa@m17n.org