bug#47074: Replace XPM icons with Unicode codepoints in customize/widgets

[Eli Zaretskii]

> Date: Thu, 11 Mar 2021 23:49:54 +0000
> From: Alan Third <alan@idiocy.org>
> Cc: Stefan Kangas <stefan@marxist.se>, 47074@debbugs.gnu.org
> 
> I've been thinking about this, and assuming we can extract the font
> name and size from the face in C then we can create a default CSS
> stylesheet that should make 1em in an SVG equivalent to the actual
> Emacs font height.

The font details can be accessed from Lisp as well, if that's more
convenient.

> Alas it doesn't resize the image as you scale with C-x C-+.

Why not? what is preventing that?

> Perhaps there is some way to mark certain SVGs as part of the UI and
> regenerate them?
> 
> Yet another alternative is to define a different text property (or
> whatever) that only draws SVGs, but on the fly so there's no caching
> and we can put them anywhere in the frame. But that might not be a
> good idea.

if these two paragraphs explain why the images currently don't resize
with the text scale, I don't think I follow the reasoning.  Please
elaborate.