Bug 491398

Summary:	Header-color-using apps don't get the right colors after switching to them using Alt+Tab with tabbox UI visible
Product:	[Plasma] kwin	Reporter:	Nate Graham <nate>
Component:	tabbox	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	ales.astone, kde, postix, vlad.zahorodnii
Priority:	NOR	Keywords:	regression
Version First Reported In:	6.2.0
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:	88c260ab261cb79425cbe5755c6c2758a4b3c19f	Version Fixed/Implemented In:	6.3.0
Sentry Crash Report:

Description Nate Graham 2024-08-07 15:30:59 UTC

SUMMARY
Git master everything built against Qt 6.7.2 on Fedora KDE 40.

If I Alt+Tab between Breeze-themed windows (e.g. Dolphin and Kate) in such a way that the tabbox UI actually appears, the windows' header areas below the SSD titlebar will fail to switch their color properly.


STEPS TO REPRODUCE:
1. Be using the default Breeze Light color scheme
2. Open Kate and Dolphin
3. Focus Kate
4. Hold down Alt
5. Press tab
6. Wait for the tabbox UI to appear
7. Press Tab enough times to go to Dolphin
8. release Alt


OBSERVED RESULT
Dolphin's toolbar background color isn't the same color as its titlebar


EXPECTED RESULT
They both match in color

Comment 1 Nate Graham 2024-08-07 15:35:26 UTC

This was caused by https://invent.kde.org/plasma/kwin/-/merge_requests/6160.

Comment 2 Vlad Zahorodnii 2024-08-07 17:04:36 UTC

The issue is caused by qtwayland synchronizing QWindow::isActive() to the wl_keyboard focus instead of using the xdg_toplevel.activated state.

FWIW The same issue can be observed on X11. I'm not sure whether it can be considered as a regression because if the task switcher handled input focus as expected, the behavior would be the same both in the Xorg session and the Wayland session.

Comment 3 Vlad Zahorodnii 2024-08-07 17:05:52 UTC

s/the behavior would be the same/the behavior would be the same from the get go/

Comment 4 Nate Graham 2024-08-07 17:06:46 UTC

Well, it wasn't happening before that commit and now it is, so I think it counts as a regression. :)  It's at least a visual regression. If we ship this, we'll end up with tons of bug reports about it, like Bug 433569, which is similarly minor but highly noticeable.

Comment 5 Nate Graham 2024-10-15 21:45:28 UTC

Appears to be fixed with today's git master!