Bug 439792

Summary: Background wallpaper flashes for a moment when window enters or leaves Full screen or Maximized states
Product: [Plasma] kwin Reporter: pikachu <radicalone385>
Component: effects-variousAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED FIXED    
Severity: normal CC: nate
Priority: NOR Keywords: regression
Version First Reported In: 5.22.3   
Target Milestone: ---   
Platform: Neon   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: The file contains a video of konsole entering and leaving full screen

Description pikachu 2021-07-13 09:12:50 UTC
Created attachment 140017 [details]
The file contains a video of konsole entering and leaving full screen

SUMMARY
Background flashing for a moment when window enters or leaves fullscreen. It is always observed in Firefox and Konsole. In other applications it is observed most of the time.
NOTE:
 This happens even when translucent effect is disabled

STEPS TO REPRODUCE
1. Make sure both Full Screen and Maximize animations are turned on in Desktop effects.Use Breeze light theme to observe this easily.
2. Open any application. Make sure all other applications are minimized.
3. Maximize window and leave Full screen(simply press maximize button again).Do this repeatedly.

OBSERVED RESULT
Background comes into view for a moment when window enters or leaves Full screen as if the window is translucent.

EXPECTED RESULT
Only the application window should be in view while entering or leaving Full screen. Any other apps or wallpaper in background should not flash.

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: KDE Neon 5.22
(available in About System)
KDE Plasma Version: 5.22.3
KDE Frameworks Version: 5.83.0
Qt Version: 5.15.3

ADDITIONAL INFORMATION
Comment 1 Nate Graham 2021-08-03 04:01:30 UTC
Can confirm. Happens with maximization effect too, which makes sense since the same effect is now used for both.