Bug 442159

Summary:	Adaptive transparency / floating reacts to windows on wrong screen after screen configuration changes
Product:	[Plasma] plasmashell	Reporter:	Sławek <slawek>
Component:	Panel	Assignee:	Plasma Bugs List <plasma-bugs>
Status:	RESOLVED FIXED
Severity:	normal	CC:	firlaevhanskde.upstream314, natalie_clarius, nate, niccolo.venerandi, notmart
Priority:	NOR
Version First Reported In:	5.27.7
Target Milestone:	1.0
Platform:	Arch Linux
OS:	Linux
Latest Commit:		Version Fixed In:
Sentry Crash Report:

Description Sławek 2021-09-08 08:14:20 UTC

SUMMARY
Adaptive transparency works fine but when window on different screen is maximized


STEPS TO REPRODUCE
1. I have 3 monitors setup. The middle one is set as primary one and on this one I have a panel.
2. Maximize window on the primary screen (middle one) - panel is still transparent
3. Maximize window on the left screen (not primary one) - panel is becoming solid.

OBSERVED RESULT


EXPECTED RESULT
Panel becomes solid when window on the screen with panel is maximized.

SOFTWARE/OS VERSIONS 
Linux/KDE Plasma: Arch Linux
(available in About System)
KDE Plasma Version: 5.22.5
KDE Frameworks Version: 5.85
Qt Version: 5.15.2

ADDITIONAL INFORMATION
Kernel Version: 5.13.13-arch1-1 (64-bit)
Graphics Platform: X11

Comment 1 Natalie Clarius 2022-12-04 20:03:15 UTC

I can reproduce this, and it affects both adaptive transparency and floating. As far as I can test, it occurs only when the display configuration changes during the session, and `plasmashell --replace` fixes it. So I suspect it's something to the effect that the panel code misses to get a signal when the display config changes and is triggered to update its screen map accordingly.

Comment 2 Firlaev-Hans 2023-06-03 14:58:20 UTC

(In reply to Natalie Clarius from comment #1)
> I can reproduce this, and it affects both adaptive transparency and
> floating. As far as I can test, it occurs only when the display
> configuration changes during the session, and `plasmashell --replace` fixes
> it. So I suspect it's something to the effect that the panel code misses to
> get a signal when the display config changes and is triggered to update its
> screen map accordingly.

I'm noticing the same issue as well sometimes when I attach or detach my external monitor on my laptop, especially if I'm doing it several times in one session.

Comment 3 Firlaev-Hans 2023-09-01 09:08:12 UTC

Floating panels are affected in the same way as transparency:

When plasmashell was started with only my internal display active and then I plug in the external monitor (which then becomes my primary monitor, thus my panel moves there), the panel defloats and becomes opaque when a window on my laptop display "touches" it even though it's located on the external display, and it stays floating and transparent when only a window on that display touches it.

Comment 4 Natalie Clarius 2023-12-20 03:09:31 UTC

This seems to be fixed in Plasma 6, I can't reproduce it there.