How do i use style on a scale?

[MatheusTT]

Sorry if it is simple, but i can't figure it out how to change the colors of a scale widget conditionally. I got a widget that i use on a sidebar for volume control, and i was trying to make it change the color of the scale if the master volume is muted. This is what i did so far:

Did someone do something similar?

[viandoxdev]

Set a class conditionally and style that class, the css that goes into :style isn't scss, since it's passed straight to GTK.

[MatheusTT]

Ok, that's solves the problem with my widget, but i have another one that is a music widget, and i was wondering if i could get the colors from the cover and use it to theme the scales, is it possible, or it will just have to use a "static color"?

[viandoxdev]

you can probably do that with a literal widget and some imagemagick/libvip magic but i don't know how it would perform (might be a bit slow so you'd want to cache things, i.e hash name and artist and use that has a filename in a directory).

[MatheusTT]

Sorry, I didn't spoke it right, i already have a script to fetch the colors. I didn't thought of using a literal widget, but then how yould the colors change dinamically? is there some way to do a temporary .scss file?

[viandoxdev]

Thats a pretty hard problem, probably something you'd be better off writing a patch for (native performance), you might be able to use gtk css variables but I doubt it. Other than that you'd have to hack something with an invisible scale over (overlay widget) a styled box that looks like the scale.