Bug 485312 - On X11, Window appears in task bar of wrong screen in multiscreen setup
Summary: On X11, Window appears in task bar of wrong screen in multiscreen setup
Status: REPORTED
Alias: None
Product: plasmashell
Classification: Plasma
Component: Task Manager and Icons-Only Task Manager widgets (show other bugs)
Version: 6.0.3
Platform: openSUSE Linux
: NOR normal
Target Milestone: 1.0
Assignee: Plasma Bugs List
URL:
Keywords: multiscreen, regression
Depends on:
Blocks:
 
Reported: 2024-04-10 08:39 UTC by Thorolf E.R. Weißhuhn
Modified: 2024-07-12 08:01 UTC (History)
5 users (show)

See Also:
Latest Commit:
Version Fixed In: 6.0.5
Sentry Crash Report:


Attachments
window whole or mostly on left monitor in task bar of right monitor (671.96 KB, image/png)
2024-06-04 05:02 UTC, Thorolf E.R. Weißhuhn
Details

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Description Thorolf E.R. Weißhuhn 2024-04-10 08:39:04 UTC
SUMMARY
In a multi-screen setting, a window that is positioned close to the neighbor screen can appear on the taskbar of that other screen (ie not of the screen that the window is actually on). Even if no part of the window appears on that other screen.


STEPS TO REPRODUCE
1. Set up two screens side by-side, and have a panel with a task bar in each. 
2. Test: Have a narrow window open on one screen, move it towards the border to the next screen.

OBSERVED RESULT
At one point, the window's representation in the task bar jumps to the task bar of the neighbor screen, but before the window even touches the screen border.


EXPECTED RESULT
Window should appear in the task bar of the same screen that the window is on.


SOFTWARE/OS VERSIONS
Operating System: openSUSE Tumbleweed 20240407
KDE Plasma Version: 6.0.3
KDE Frameworks Version: 6.0.0
Qt Version: 6.6.3
Kernel Version: 6.8.4-rc1-1-default (64-bit)
Graphics Platform: X11


ADDITIONAL INFORMATION
I have observed this with an internal/external screen setup on a laptop.

Brief (inexhaustive) tests showed that:
- It happens only if the external is to the left of the internal screen.
- It is not dependent on the primary/secondary screen setting.
- It happens in several resolutions (small number only tested).
- The point of task bar jump is determined by the position of *boths* vertical window borders. Moving either border (ie, changing width of window while it is positioned near the neighbor screen) has the same effect.


IDLE SPECULATIONS
=> Is there a position calculation based on window *centre*?
=> Is the task bar that the window is assigned to determined by a calculation involving the sum total of screen widths?
Comment 1 meku 2024-05-15 01:16:53 UTC
I have observed this with a vertical monitor layout.

Screen layout: a primary screen and a second screen below it

STEPS TO REPRODUCE
1. taskbar and window on the primary screen
2. shrink height of window, in this config the bug triggers when window is less than half the primary screen height.
3. move window towards bottom edge and it will disappear from taskbar before reaching the edge

ADDITIONAL INFORMATION
1. the shorter the window, the further away from the bottom edge it will disappear from taskbar
2. this only happens on edges where there is an adjacent screen.

SOFTWARE/OS VERSIONS
Operating System: openSUSE Tumbleweed 20240429
KDE Plasma Version: 6.0.4
KDE Frameworks Version: 6.1.0
Qt Version: 6.7.0
Graphics Platform: X11
Comment 2 Nate Graham 2024-05-16 18:56:05 UTC
Does it happen on Wayland for either of yo, or only on X11?
Comment 3 Thorolf E.R. Weißhuhn 2024-05-17 08:17:22 UTC
No Wayland here, sry.
Comment 4 meku 2024-05-21 12:17:49 UTC
Not seen in Wayland
Comment 5 Nate Graham 2024-05-21 17:54:54 UTC
Thanks. I assume this didn't happen in Plasma 5, right?
Comment 6 Thorolf E.R. Weißhuhn 2024-05-21 18:52:46 UTC
Don't remember having seen that before 6.
Comment 7 Nate Graham 2024-05-22 18:30:22 UTC
Thanks.
Comment 8 Fushan Wen 2024-05-23 00:57:54 UTC
Cannot reproduce on X11 either
Comment 9 Nate Graham 2024-05-23 16:21:06 UTC
Hmm, maybe it got fixed in 6.0.5. Thorolf, can you upgrade to 6.0.5 (it was released yesterday) and try again?
Comment 10 Thorolf E.R. Weißhuhn 2024-05-23 16:59:54 UTC
6.0.5 is not yet in the openSUSE updates. Their testing usually takes only a few days, I will keep an eye on it.
Comment 11 Thorolf E.R. Weißhuhn 2024-06-04 05:02:40 UTC
Created attachment 170124 [details]
window whole or mostly on left monitor in task bar of right monitor

Bug remained in 6.0.5.
Left Task Manager does not even tough window border; Firefox windows do not enter right monitor; Info Center only in a narrow strip on right monitor
Comment 12 Thorolf E.R. Weißhuhn 2024-06-04 05:04:18 UTC
Image cropped except bottom.
Comment 13 Nate Graham 2024-06-26 23:56:48 UTC
Are you able to reproduce this issue in Plasma 6.1, which was released last week?
Comment 14 Thorolf E.R. Weißhuhn 2024-06-27 17:24:49 UTC
Yes, still the same.

(Why is it not possible to add an attachment to a comment?)
Comment 15 Bug Janitor Service 2024-07-12 03:47:02 UTC
Dear Bug Submitter,

This bug has been in NEEDSINFO status with no change for at least
15 days. Please provide the requested information as soon as
possible and set the bug status as REPORTED. Due to regular bug
tracker maintenance, if the bug is still in NEEDSINFO status with
no change in 30 days the bug will be closed as RESOLVED > WORKSFORME
due to lack of needed information.

For more information about our bug triaging procedures please read the
wiki located here:
https://community.kde.org/Guidelines_and_HOWTOs/Bug_triaging

If you have already provided the requested information, please
mark the bug as REPORTED so that the KDE team knows that the bug is
ready to be confirmed.

Thank you for helping us make KDE software even better for everyone!
Comment 16 Thorolf E.R. Weißhuhn 2024-07-12 08:01:12 UTC
Just saying that the issue still exists, to keep the report from being closed.