Beautify DTP

[Hirnmoder]

Major changes

1. App icon highlighting unaffected by hover animation (Resolves "Animate hovering app icons" animates the highlight background of a focused app instead of just the app icon itself #2009)
2. Allow hover animation travel below 0%
3. Allow hover animation zoom below 100%
4. Hover highlighting independent of hover animation
5. Custom color for hover highlighting
6. Custom color for mouse down highlighting
7. Icon background with rounded corners (Resolves Round active application highlight #729 Rounded corners for focused app highlight #1647 Edit corner radius of components #1819)
8. Customize margin for app icons towards screen border and desktop (Resolves How to add some space between app icons and panel border?  #1721 Edit corner radius of components #1819)

Some visual impressions with custom settings

Change	Before	After
1
2,3
4	Either animation or highlighting
5
6
7
8

[Hirnmoder]

I've made accidentially a rebase instead of a fast-forward merge. This is why all the other commits show up. Merging should not be affected by this.
However, if you would like me to re-do the PR, just comment and I'll do it.

[Arilas]

Hey. I've tried to use your PR locally and found some bugs. Some of them are commented here in review.

Also border radius is not working for hovering and active icons. I'm not sure why.

[Arilas]

You are converting array into string

[Hirnmoder]

I don't see your point here. this._dtpSettingsSignalIds is an array of integers (signal IDs to be precise) and I concatenate two arrays. It may be not the most elegant solution, but I can't see any array-to-string conversion (even implicitly) here.
Please advise

[Hirnmoder]

Hey. I've tried to use your PR locally and found some bugs. Some of them are commented here in review.

Also border radius is not working for hovering and active icons. I'm not sure why.

Hey Arilas,
thank you for testing my PR :)

The border radius with active icon bug sounds suspicious. May I request your software stack? (so on which distribution of Linux did you test it and what was the version of GNOME?). I am still on Fedora 40 with GNOME 46 and no support for CSS variables. It is possible that my workaround-code for CSS variables works (GNOME <= 46), but my code for the actual implementation (GNOME >= 47) does not. I'll have to look into this.

For the other bugs in question, I'll leave a response directly at your code remarks.