Get accent color from system stylesheet

[danirabbit]

You can use Gtk foreign drawing API to get the correct accent color from the stylesheet. Consider this commit in Gala:

https://github.com/elementary/gala/pull/909/files#diff-7621626af936a6bd469f8302ec5666ca88e146bb87af769b507a010f30ee55d3R398

[JoseExposito]

Hi Daniel,

Thank you very much for your report!

Yes, that is something that is definitely in my wish-list and a must have for elementary OS 6.
I didn't investigate it much yet, however, I don't like the idea of adding Gtk as a dependency. It is a big one a KDE/LXQt/etc users will complain.

Do you know if there is another way of getting it? A GSetting maybe? Otherwise, I could just generate a elementary OS build with a #ifdef 🤔

[danirabbit]

Hm not reliably. I guess you could try to read /org/gnome/desktop/interface/gtk-theme and guess from a set of hardcoded colors, but this solution would work for any Gtk desktop and stylesheet

[JoseExposito]

I finally decided to use GTK to get both the background color and the border color. Reading the current theme and using a hardcoded color was just too hacky and difficult to maintain:
https://github.com/JoseExposito/touchegg/blob/master/src/utils/color.cpp#L55

I don't have access to elementary OS 6, so I can not test it with the new accent color selector. It should wok ™️ but it will be nice to test it before I release v2.0.3. Could you confirm it please?

BTW, does Gala on elementary OS 6 add a border to the tiling preview? I didn't find a reference to Gtk.STYLE_PROPERTY_BORDER_COLOR. Not sure if it is a bug or the intended behaviour.

---

For those who prefer to not install GTK and/or leave some RAM unused (this feature increases RAM usage from 800kb to ~5MB, but c'mon guys, this flies on a Raspberry Pi 4), I added a flag to NOT compile with GTK:
https://github.com/JoseExposito/touchegg/blob/master/HACKING.md#cmake--dauto_colorsonoff

[danirabbit]

I can confirm that the correct accent color is loaded on session start, but it doesn't seem to update during the session if the user changes their accent color

I don't believe we do add a border for tiling previews

Also, I added you to the allowlist for builds.elementary.io :)

[JoseExposito]

Weird, I calculate the new color just before every animated gesture...

Thank you so much for giving me access, I'll do some testing 😄