Created attachment 134712 [details]
Here is firefox with this issue (Note: I can't reproduce this, it's from another user)

I just attached a second screenshot with the same issue (so it looks) in Firefox. It's not a screenshot from me though, Firefox just works normal for me. 

Also, neither me nor the user with the firefox issue (according to what he said) uses some style configuration. Just the normal breeze theme.

The client-side titlebar buttons are not drawn by the compositing manager (kwin). So far, it looks like a GTK configuration issue.

For what it's worth, GTK applications suffer from the same issue when running in Plasma on Wayland session. However, it can be easily fixed by installing xdg-desktop-portal-gtk and gnome-settings-daemon. Hope this helps.

Hi, 
sorry for the late answer. Unfortunately installing these packages didn't resolve the issue. 
Furthermore, I also found out that the issue is X11 only. I don't have that problem on wayland.

Any other ideas?

Created attachment 138185 [details]
Same Issue in Akira (GTK, Vala)

I found another application with this issue. It's like Planner as well a Vala GTK Application.

>I don't have that problem on wayland.

On wayland GTK apps are surprisingly better at using our decorations.
As for this, it's not a kwin issue so I'll move to a general pool where it can be triaged somewhere else.

Ah this. It was fixed in Plasma 5.22 IIRC.

The issue is not fixed for me. I'm on 5.22.1 and Frameworks 5.83.0

*** Bug 440687 has been marked as a duplicate of this bug. ***

This needs to be tested after [!31](https://invent.kde.org/plasma/kde-gtk-config/-/merge_requests/31) is merged.

*** Bug 441739 has been marked as a duplicate of this bug. ***

I'm reopening this because I still see this issue with the latest released version, at least with a certain type of window (dialogs). You can test this with the eog application (Gnome's image viewer) by opening the preferences dialog window. Stuff I've noticed:

window_decorations.css gets added to my ~/.config/gtk-3.0/directory automatically, if I delete it and log in again.

The GTK inspector tool says that a background image is being added to the close button by window_decorations.css.

The specific issue with dialogs was reported here and closed as a dupe of this bug: https://bugs.kde.org/show_bug.cgi?id=440687 

I'm assuming that the issue is general enough that it makes sense to reopen this one. If someone disagrees, feel free to close this one again and reopen the other one. I will add myself to CC on both so I can respond to any questions if this proves hard to reproduce.

Cannot reproduce; if you can still reproduce, this is likely an issue with kde-gtk-config and not Breeze GTK. Moving this there.

(In reply to Jan Blackquill from comment #12)
> Cannot reproduce; if you can still reproduce, this is likely an issue with
> kde-gtk-config and not Breeze GTK. Moving this there.

I can still reproduce this. Here's a quick screenshot of the eye of gnome (image viewer) preferences window: https://i.imgur.com/9N4JNf6.png

It doesn't look like this bug is filed against kde-gtk-config. Do you want me to file a new bug to follow up on this issue?

we track those bugs here in systemsettings | kcm_style. So it's in the right place.

What Plasma version are you using, Adam?

(In reply to Nate Graham from comment #14)
> we track those bugs here in systemsettings | kcm_style. So it's in the right
> place.
> 
> What Plasma version are you using, Adam?

Reproduced it just now with 5.24.4, official Arch Linux package.

I can reproduce this bug in the latest release:

1. trash ~/.config/gtk-3.0
2. set global theme to Breeze
3. in kde-gtk-config, set theme to Breeze
4. set global theme to Breeze Dark
5. open Firefox
6. now titlebar buttons are misrendered

How to fix it:
1. trash ~/.config/gtk-3.0
2. in kde-gtk-config, set theme to Breeze

So seems the problem is that kde-gtk doesn't regenerate gtk config files when kde global theme changes.

(In reply to Jin Liu from comment #16)
> How to fix it:
> 1. trash ~/.config/gtk-3.0
> 2. in kde-gtk-config, set theme to Breeze
> 
> So seems the problem is that kde-gtk doesn't regenerate gtk config files
> when kde global theme changes.

This didn't fix the issue for me, I think you might be seeing something else. Maybe you can provide a screenshot of what you see? I think if KDE is supposed to changing the gtk config when the global theme changes (maybe Nate can confirm?), if it is not doing that, it's probably a separate bug.

Created attachment 148987 [details]
firefox, breeze dark changed to light

Created attachment 148988 [details]
firefox, breeze light changed to dark

(In reply to Adam Fontenot from comment #17)
> (In reply to Jin Liu from comment #16)
> > How to fix it:
> > 1. trash ~/.config/gtk-3.0
> > 2. in kde-gtk-config, set theme to Breeze
> > 
> > So seems the problem is that kde-gtk doesn't regenerate gtk config files
> > when kde global theme changes.
> 
> This didn't fix the issue for me, I think you might be seeing something
> else. Maybe you can provide a screenshot of what you see? I think if KDE is
> supposed to changing the gtk config when the global theme changes (maybe
> Nate can confirm?), if it is not doing that, it's probably a separate bug.

Uploaded two screenshots. I think they are quite like the visual glitch in previous screenshots (even with the same strange-shaped red hover effect in the second (firefox) screenshot, although not captured in my screenshots).

Can't currently repro this with Plasma 5.26, testing eog 42.3. Assuming it was fixed.

Going to close this issue. If there are issues that appear without theme changes (e.g. you see the problem after a reboot), please re-open the bug.

If you see an issue where GTK applications don't update after making changes to your theme, please file a new bug.