tree-widget with unicode box chars

tree-widget with unicode box chars

[JD Smith]

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tree-widget.el provides both xpm icons and crude plain-text versions of the tree glyphs.  Most fixed-space fonts have unicode box-drawing characters, which can be used to draw high quality text-only trees.  Such unicode trees look identical in graphical or terminal Emacs (see attached for an example).  

This works just fine, but one small change is needed to accommodate this style.  `tree-widget-guide’ specifies a single vertical bar “guide” widget.  In the unicode tree, two separate vertical bars are needed — one “plain” (│), and one which connects to the horizontal “handle” preceding the node (├). A patch is attached implementing this.  For the default graphical-icon version to continue working, linking from nohandle-guide.* -> guide.* in etc/images/tree-widget/* would be necessary.


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--- -	2022-06-04 22:15:22.000000000 -0400
+++ tree-widget.el	2022-06-04 22:15:20.000000000 -0400
@@ -319,6 +319,7 @@
   '(
     ("guide"     . arrow)
     ("no-guide"  . arrow)
+    ("nohandle-guide" . arrow)
     ("end-guide" . arrow)
     ("handle"    . arrow)
     ("no-handle" . arrow)
@@ -440,6 +441,13 @@
   :format    "%t"
   )
 
+(define-widget 'tree-widget-nohandle-guide 'item
+  "Vertical guide line, when there is no handle."
+  :tag       " |"
+  ;;:tag-glyph (tree-widget-find-image "nohandle-guide")
+  :format    "%t" 
+  )
+
 (define-widget 'tree-widget-end-guide 'item
   "End of a vertical guide line."
   :tag       " \\=`"
@@ -483,6 +491,7 @@
   :empty-icon     'tree-widget-empty-icon
   :leaf-icon      'tree-widget-leaf-icon
   :guide          'tree-widget-guide
+  :nohandle-guide 'tree-widget-nohandle-guide
   :end-guide      'tree-widget-end-guide
   :no-guide       'tree-widget-no-guide
   :handle         'tree-widget-handle
@@ -612,11 +621,13 @@
 ;;;; Expanded node.
         (let ((args     (widget-get tree :args))
               (guide    (widget-get tree :guide))
+              (nohandle-guide (widget-get tree :nohandle-guide))
               (noguide  (widget-get tree :no-guide))
               (endguide (widget-get tree :end-guide))
               (handle   (widget-get tree :handle))
               (nohandle (widget-get tree :no-handle))
               (guidi    (tree-widget-find-image "guide"))
+              (nohandle-guidi (tree-widget-find-image "nohandle-guide"))
               (noguidi  (tree-widget-find-image "no-guide"))
               (endguidi (tree-widget-find-image "end-guide"))
               (handli   (tree-widget-find-image "handle"))
@@ -648,8 +659,8 @@
             ;; Insert guide lines elements from previous levels.
             (dolist (f (reverse flags))
               (widget-create-child-and-convert
-               tree (if f guide noguide)
-               :tag-glyph (if f guidi noguidi))
+               tree (if f nohandle-guide noguide)
+               :tag-glyph (if f nohandle-guidi noguidi))
               (widget-create-child-and-convert
                tree nohandle :tag-glyph nohandli))
             ;; Insert guide line element for this level.

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Re: tree-widget with unicode box chars

[Lars Ingebrigtsen]

JD Smith <jdtsmith@gmail.com> writes:

> This works just fine, but one small change is needed to accommodate
> this style.  `tree-widget-guide’ specifies a single vertical bar
> “guide” widget.  In the unicode tree, two separate vertical bars are
> needed — one “plain” (│), and one which connects to the horizontal
> “handle” preceding the node (├). A patch is attached implementing
> this.

Thanks; pushed to Emacs 29.

This change was small enough to apply without assigning copyright to the
FSF, but for future patches you want to submit, it might make sense to
get the paperwork started now, so that subsequent patches can be applied
speedily. Would you be willing to sign such paperwork?

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

Re: tree-widget with unicode box chars

[JD Smith]

Great.   Please don’t forget to link the images in etc/images/tree-widget/* (e.g. nohandle-guide.xpm -> guide.xpm), or the default icon-tree will have a mismatched & ugly vertical guide.  There are two “theme” directories there: `default' and `folder'. 
 
JD

> On Jun 5, 2022, at 10:00 AM, Lars Ingebrigtsen <larsi@gnus.org> wrote:
> 
> JD Smith <jdtsmith@gmail.com> writes:
> 
>> This works just fine, but one small change is needed to accommodate
>> this style.  `tree-widget-guide’ specifies a single vertical bar
>> “guide” widget.  In the unicode tree, two separate vertical bars are
>> needed — one “plain” (│), and one which connects to the horizontal
>> “handle” preceding the node (├). A patch is attached implementing
>> this.
> 
> Thanks; pushed to Emacs 29.

Re: tree-widget with unicode box chars

[Lars Ingebrigtsen]

JD Smith <jdtsmith@gmail.com> writes:

> Great.  Please don’t forget to link the images in
> etc/images/tree-widget/* (e.g. nohandle-guide.xpm -> guide.xpm), or
> the default icon-tree will have a mismatched & ugly vertical guide.
> There are two “theme” directories there: `default' and `folder'.

Now done, but as copies, since we don't seem to do symlinks in the repo.

-- 
(domestic pets only, the antidote for overdose, milk.)
   bloggy blog: http://lars.ingebrigtsen.no

Re: tree-widget with unicode box chars

[Daniele Nicolodi]

On 05/06/2022 04:21, JD Smith wrote:
> tree-widget.el provides both xpm icons and crude plain-text versions of 
> the tree glyphs.  Most fixed-space fonts have unicode box-drawing 
> characters, which can be used to draw high quality text-only trees. 
>   Such unicode trees look identical in graphical or terminal Emacs (see 
> attached for an example).

Which unicode characters did you use to draw the tree in the image?

Thank you.

Cheers,
Dan