On Sun, May 04, 2025 at 07:17:46PM +0200, Manuel Giraud wrote:
> Thanks Alan.  I've tested your patch and here is what I observe. What's
> good:
> 
>        - SVG Emacs "widgets" are still using the default face color and
>          are updating accordingly when changing theme
> 
>        - I use Gnus and I see the same behaviour for the SVG icon in the
>          modeline
> 
>        - The german flag example provided by Billy is displayed
>          correctly (filled with black where needed) whatever the theme
>          in use
> 
>        - The example from Ihor shows 'x²=2' written in white on black
>          whatever the theme in use

Thanks for checking.

> What's not so good:
> 
> I use DocView (with mupdf to generate SVG pages) and I have set
> 'doc-view-svg-face' to "inherit default" so that DocView buffers are
> also following the theme.  This used to work but now, with this patch,
> it does not render correctly.  For example, the text stays black instead
> of white with a dark background theme.
> 
> Maybe, it is something that should be fixed in DocView (?)

We could probably fix it by getting Docview to set the :css property
for the SVG image to something like:

    svg {
      fill: currentcolor;
    }

Is the background OK?

The attached might work, but only if you're using librsvg 2.48 or
above... I can think of a way to fix *that* problem, but it'll need a
little more thought.

-- 
Alan Third