Bug 449050 - System settings flickering when quickly moving mouse cursor over the window
Summary: System settings flickering when quickly moving mouse cursor over the window
Status: RESOLVED UPSTREAM
Alias: None
Product: systemsettings
Classification: Applications
Component: general (other bugs)
Version First Reported In: 5.23.5
Platform: Other Linux
: NOR normal
Target Milestone: ---
Assignee: Plasma Bugs List
URL: https://gitlab.freedesktop.org/mesa/m...
Keywords:
Depends on:
Blocks:
 
Reported: 2022-01-24 08:28 UTC by Andrea Ippolito
Modified: 2022-01-25 06:01 UTC (History)
1 user (show)

See Also:
Latest Commit:
Version Fixed/Implemented In:
Sentry Crash Report:


Attachments

Note You need to log in before you can comment on or make changes to this bug.
Description Andrea Ippolito 2022-01-24 08:28:02 UTC
SUMMARY
As per title.
This seems to affect System settings only, as I have yet to encounter this behavior in other KDE apps.
Video attached.
I am using openSuse Tumbleweed with Wayland and pipewire (I thought pipewire was sth for audio only, but once I saw it showing up in OBS Studio for video capture, I'm no longer sure, hence I'm mentioning it).
I am using a custom font (Poppins) instead of the default, and scaling at 200%.

STEPS TO REPRODUCE
1. open System Settings (Wayland session)
2. Go to any appearance category and quickly move the mouse cursor back and forth over the available options (e.g. in the Colors section move over the previous quickly and for a few seconds. Also happens often when hovering over Global Theme previews). Also in Fonts it's visible.

OBSERVED RESULT
no UI flickering

EXPECTED RESULT
UI flickering - check video attached. See how all the UI widgets in the Fonts panel are "refreshed" causing flickering (including the "Fonts" title in the header section). Same goes for Colors (2nd part of the video)

SOFTWARE/OS VERSIONS
Windows: 
macOS: 
Linux/KDE Plasma: 
(available in About System)
KDE Plasma Version: 
KDE Frameworks Version: 
Qt Version: 

ADDITIONAL INFORMATION
Comment 1 Andrea Ippolito 2022-01-24 08:32:06 UTC
Sorry, I dunno how to edit.

ADDITIONAL INFORMATION
Could not reproduce on X11.
Could not reproduce on Kubuntu 21.10 live media (logged out of the default X11 session and logged in to a Wayland one - works fine)
--> Kubuntu doesn't seem to apply scaling on neither X11 or Wayland sessions - wonder if scaling somehow plays a role in this issue
Could reproduce on fedora 35 KDE live media (logs into Wayland by default).
--> fedora auto scales to 200% I think when starting the live media
Could reproduce on my openSuse Tumbleweed install by booting read-only snapshot of 18Jan (although I think that it's still on KDE 5.23.5)

I wonder if this is somehow related to a recent version of Qt?

On the other hand, I haven't encountered this issue on any other KDE apps, so far.
Comment 2 Andrea Ippolito 2022-01-24 08:33:21 UTC
(In reply to andrea.ippo from comment #0)
> SUMMARY
> As per title.
> This seems to affect System settings only, as I have yet to encounter this
> behavior in other KDE apps.
> Video attached.
> I am using openSuse Tumbleweed with Wayland and pipewire (I thought pipewire
> was sth for audio only, but once I saw it showing up in OBS Studio for video
> capture, I'm no longer sure, hence I'm mentioning it).
> I am using a custom font (Poppins) instead of the default, and scaling at
> 200%.
> 
> STEPS TO REPRODUCE
> 1. open System Settings (Wayland session)
> 2. Go to any appearance category and quickly move the mouse cursor back and
> forth over the available options (e.g. in the Colors section move over the
> previous quickly and for a few seconds. Also happens often when hovering
> over Global Theme previews). Also in Fonts it's visible.
> 
> OBSERVED RESULT
> no UI flickering
> 
> EXPECTED RESULT
> UI flickering - check video attached. See how all the UI widgets in the
> Fonts panel are "refreshed" causing flickering (including the "Fonts" title
> in the header section). Same goes for Colors (2nd part of the video)
> 
> SOFTWARE/OS VERSIONS
> Windows: 
> macOS: 
> Linux/KDE Plasma: 
> (available in About System)
> KDE Plasma Version: 
> KDE Frameworks Version: 
> Qt Version: 
> 
> ADDITIONAL INFORMATION

Couldn't upload video as it's too big. Find it here:

https://photos.app.goo.gl/j1ddT769mzwGACUX8
Comment 3 Nate Graham 2022-01-24 22:48:05 UTC
It's a recent Mesa regression: https://gitlab.freedesktop.org/mesa/mesa/-/issues/5731
Comment 4 Andrea Ippolito 2022-01-25 06:01:55 UTC
(In reply to Nate Graham from comment #3)
> It's a recent Mesa regression:
> https://gitlab.freedesktop.org/mesa/mesa/-/issues/5731

Thanks, following!