Bug 482253 - Visual glitch with bottom-most widget when left screen edge vertical panel de-floats
Summary: Visual glitch with bottom-most widget when left screen edge vertical panel de...
Status: RESOLVED FIXED
Alias: None
Product: plasmashell
Classification: Plasma
Component: Panel (show other bugs)
Version: 6.0.0
Platform: NixOS Linux
: NOR minor
Target Milestone: 1.0
Assignee: Plasma Bugs List
URL:
Keywords: qt6
Depends on:
Blocks:
 
Reported: 2024-03-02 21:58 UTC by Noitatsidem
Modified: 2024-06-25 10:41 UTC (History)
3 users (show)

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


Attachments
Brief clip showing the problem (1.26 MB, video/webm)
2024-03-02 21:58 UTC, Noitatsidem
Details

Note You need to log in before you can comment on or make changes to this bug.
Description Noitatsidem 2024-03-02 21:58:13 UTC
Created attachment 166318 [details]
Brief clip showing the problem

SUMMARY
When using a vertical panel that does not take up the whole screen, the panel and its contents will vibrate when maximizing or unmaximizing windows, and also when the panel transitions from floating to non-floating when windows touch it. Note this is on the stable 6.0 release from Nixos unstable - for some reason 6.0 stable isn't added to the versions list on here yet so I picked master.


STEPS TO REPRODUCE
1.  create a vertical panel that does not take up the whole screen (in my case I have a unity-like setup, don't judge!)
2. maximize and unmaximize windows
or
3. let windows touch the panel

OBSERVED RESULT
panel will vibrate.

EXPECTED RESULT
to see the smooth animations I've come to expect from plasma

SOFTWARE/OS VERSIONS
Linux/KDE Plasma:  Nixos unstable, kernel version  6.7.6
KDE Plasma Version: 6.0
KDE Frameworks Version: 6.0 6.6
Qt Version: 6.6.2
Comment 1 Nate Graham 2024-03-05 20:23:50 UTC
Looks like the issue is with the Peek at Desktop widget at the bottom? I'm unable to reproduce it with my vertical left side panel, which is how I normally use the system.
Comment 2 Noitatsidem 2024-03-09 19:09:26 UTC
(In reply to Nate Graham from comment #1)
> Looks like the issue is with the Peek at Desktop widget at the bottom? I'm
> unable to reproduce it with my vertical left side panel, which is how I
> normally use the system.

It happens regardless of what widget I have down there. Prior I had a trash icon. It seems like the animation is playing wrong. It's on intel graphics if that might have something to do with it. It's just confusing to me because plasma 5 on the same hardware doesn't demonstrate the same behavior.
Comment 3 Noitatsidem 2024-03-11 14:39:24 UTC
(In reply to Noitatsidem from comment #2)
> (In reply to Nate Graham from comment #1)
> > Looks like the issue is with the Peek at Desktop widget at the bottom? I'm
> > unable to reproduce it with my vertical left side panel, which is how I
> > normally use the system.
> 
> It happens regardless of what widget I have down there. Prior I had a trash
> icon. It seems like the animation is playing wrong. It's on intel graphics
> if that might have something to do with it. It's just confusing to me
> because plasma 5 on the same hardware doesn't demonstrate the same behavior.

I notice that the title mentions floating now. I just wanted to say that this visual bug is present when floating is disabled too, which is why I didn't list it in the steps to reproduce part of my post.
Comment 4 Noitatsidem 2024-03-27 14:14:55 UTC
So I've played around with it some more and notice the following:
the way plasma desktop handles panels was changed a bit, in previous versions in multi-panel configurations you had to manually set the panel size so they wouldn't overlap. In Plasma 6, it does this automatically (in fact I haven't even found a way to manually set the panel's size in a precise manner as you could before. but that's fine not really a problem for my use case) - however I think this is where the issue is. I notice the bottom icon likes to stay offset off the screen by a small amount, I think this might be the amount of space my top panel takes. Sometimes it does settle on the correct position though, but it frequently likes to glitch between them when messing with windows as shown above. This would also explain why Nate couldn't reproduce it, I think the presence of a second panel is the difference. So I think the steps to reproduce might be 

1.  create a horizontal panel fill width
2. create a vertical panel to fill width (it will *try* to automatically accommodate horizontal panel with varying success) 
2. maximize and unmaximize windows
or
3. let windows touch the panel

Or at least, this is as far as I've been able to work it out as an end user who's barely even started to dabble in python. If there's anything I can do to help get this addressed I'll absolutely do anything I can.
Comment 5 Niccolò Venerandi 2024-03-28 11:42:01 UTC
Good job, I can reproduce the bug now. The issue is indeed in having this two-panels layout.
Comment 6 Nate Graham 2024-05-19 21:28:58 UTC
Can you try again with Plasma 6.0.5 which will be released in a few days? Something that was changed recently should have fixed this, and I can't reproduce it anymore myself.
Comment 7 Noitatsidem 2024-05-21 08:18:14 UTC
(In reply to Nate Graham from comment #6)
> Can you try again with Plasma 6.0.5 which will be released in a few days?
> Something that was changed recently should have fixed this, and I can't
> reproduce it anymore myself.

Absolutely, will test it out as soon as I get home and it lands in my repos. For the person who did the patch, I made a post in the sponsored work section of the forums if they're interested in compensation. https://discuss.kde.org/t/bug-fix-visual-glitch-with-multi-panel-setup-bug-482253/15785
Comment 8 Noitatsidem 2024-05-27 16:17:50 UTC
I just had the opportunity to test on fedora kinoite & the issue seemed to still be present.
Comment 9 Bug Janitor Service 2024-06-11 03:46:29 UTC Comment hidden (spam)
Comment 10 Nate Graham 2024-06-12 15:33:54 UTC
Aha, this may also be fixed in Plasma 6.1, where we improved the way panels on adjacent screen edges work. Can you try again there? Plasma 6.1 should be released in about a week JFYI.
Comment 11 Noitatsidem 2024-06-25 10:41:57 UTC
(In reply to Nate Graham from comment #10)
> Aha, this may also be fixed in Plasma 6.1, where we improved the way panels
> on adjacent screen edges work. Can you try again there? Plasma 6.1 should be
> released in about a week JFYI.

I can confirm that this issue is no longer present, tested on Arch just now.