Bug 455898 - Rectangular flickering in menus when blur effect is enabled
Summary: Rectangular flickering in menus when blur effect is enabled
Status: REOPENED
Alias: None
Product: kwin
Classification: Plasma
Component: wayland-generic (show other bugs)
Version: 5.25.1
Platform: openSUSE Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords: wayland
: 456506 (view as bug list)
Depends on:
Blocks:
 
Reported: 2022-06-24 18:56 UTC by postix
Modified: 2023-08-04 11:50 UTC (History)
3 users (show)

See Also:
Latest Commit:
Version Fixed In:

Attachments
Screenshot: The brighter part belongs to the flickering (340.35 KB, image/jpeg)
2022-06-24 18:56 UTC, postix 		Details
kWin Support Info (6.85 KB, text/plain)
2022-06-24 18:57 UTC, postix 		Details
Screenrecording: Speedcrunch on Plasma 5.27.6 Wayland, Tumbleweed (2.37 MB, video/x-matroska)
2023-07-07 11:01 UTC, postix 		Details
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Description postix 2022-06-24 18:56:54 UTC 
Created attachment 150128 [details]
Screenshot: The brighter part belongs to the flickering

SUMMARY

Interestingly, the bug is not visible when taking a screenshot with spectacle or recording the whole screen with OBS. That's why I took a picture with the phone.


STEPS TO REPRODUCE
1.  Open VLC
2.  Open one of VLC's window, where the first item is grayed out so that it doesn't trigger any action 

OBSERVED RESULT
A rectangular part of the menu flickers rather fast. Happens on both screens, but with a different color.


SOFTWARE/OS VERSIONS
Operating System: openSUSE Tumbleweed 20220623
KDE Plasma Version: 5.25.1
KDE Frameworks Version: 5.95.0
Qt Version: 5.15.2
Kernel Version: 5.18.4-1-default (64-bit)
Graphics Platform: Wayland
Graphics Processor: AMD Radeon RX 580 Series
Comment 1 postix 2022-06-24 18:57:11 UTC 
Created attachment 150129 [details]
kWin Support Info
Comment 2 David Edmundson 2023-07-06 10:47:03 UTC 
Cannot reproduce, but in any case if it's only one app that's unlikely to be a kwin bug.
Comment 3 postix 2023-07-07 11:01:46 UTC 
Created attachment 160121 [details]
Screenrecording: Speedcrunch on Plasma 5.27.6 Wayland, Tumbleweed

(In reply to David Edmundson from comment #2)
> but in any case if it's only one app that's unlikely to be
> a kwin bug.

It also happens in Speedcrunch 0.12 compiled against Qt 5.15.9 for me.  Please see the screen recording. Hopefully this helps in reproducing it.
Comment 4 postix 2023-07-07 11:08:08 UTC 
Bug #456506 seems to be related as I also can only reproduce it so far in these to applications: VLC and Speedcrunch.
Comment 5 postix 2023-07-07 11:13:40 UTC 
(In reply to postix from comment #4)
> Bug #456506 seems to be related as I also can only reproduce it so far in
> these to applications: VLC and Speedcrunch.

Supplement: Can also reproduce it in Konsole 23.04.2: Here it flickers only very shortly and not always when hovering "View" or "Bookmarks" in the menu.
Comment 6 David Edmundson 2023-07-07 12:30:16 UTC 
Do you have some sort of transparent/blurred menus?
Comment 7 David Edmundson 2023-07-07 12:32:52 UTC 
*** Bug 456506 has been marked as a duplicate of this bug. ***
Comment 8 postix 2023-07-07 12:52:20 UTC 
(In reply to David Edmundson from comment #6)
> Do you have some sort of transparent/blurred menus?

Yes, they are transparent and blurred. 
I have disabled the "transparency" and "background contrast" effects in the workspace effect settings:
This issue can be toggled by enabling / disabling the "blur" effect only.
Comment 9 postix 2023-07-07 12:53:39 UTC 
Note that somehow the menus keep being transparent even after disabling the associated effect in System Settings -> Workspace effects. I haven't found any other settings to change the transparency.
Comment 10 postix 2023-07-07 12:59:46 UTC 
Also this issue is independent of the scaling factor: The flickering rectangle scales accordingly.