Bug 471416

Summary:	On secondary monitor, if user add a top horizontal panel , first monitor considers panel is in it too
Product:	[Plasma] plasmashell	Reporter:	Rafael Linux User <rafael.linux.user>
Component:	general	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED FIXED
Severity:	normal	CC:	aleixpol, kde, nicolas.fella, qydwhotmail, rafael.linux.user
Priority:	NOR
Version First Reported In:	5.27.6
Target Milestone:	1.0
Platform:	openSUSE
OS:	Linux
Latest Commit:	https://invent.kde.org/frameworks/kwindowsystem/-/commit/b59a81959e9488fe656e2e54c8a410be4641c401	Version Fixed/Implemented In:	6.0
Sentry Crash Report:
Attachments:	Screenshot just when changing to Wayland Workaround resizing panel width

Description Rafael Linux User 2023-06-25 01:29:13 UTC

Created attachment 159885 [details]
Screenshot just when changing to Wayland

SUMMARY
I have two monitors. On the top edge of the secondary monitor, I always have a panel visible that occupies the full width of the second monitor (in X11). When I log into Wayland and change the zoom of the two monitors, Plasma thinks that the horizontal pane of the secondary monitor reaches the main monitor and therefore, when I maximise the windows on the main monitor, they don't cover the top because it considers that the pane is also on the main monitor.

The only way to avoid this is to reduce the width of the secondary monitor panel by a few pixels, so that it does not touch the edge of the secondary monitor.

Issue it's similar or related to https://bugs.kde.org/show_bug.cgi?id=349220


STEPS TO REPRODUCE
1. Open session in X11
2.  Add an horizontal panel in secondary monitor, from edge to edge
3. Open session in Wayland
4. Change (increase) zoom for both monitors

OBSERVED RESULT
When a window is maximized in first monitor, window doesn't cover top area , leaving a frame with equal height that panel of second monitor.

EXPECTED RESULT
Work like in X11

SOFTWARE/OS VERSIONS
Operating System: openSUSE Tumbleweed 20230621
KDE Plasma Version: 5.27.6
KDE Frameworks Version: 5.107.0
Qt Version: 5.15.10
Kernel Version: 6.3.7-1-default (64-bit)
Graphics Platform: X11 and Wayland

Comment 1 Rafael Linux User 2023-06-25 01:29:48 UTC

Created attachment 159886 [details]
Workaround resizing panel width

Comment 2 Fushan Wen 2023-10-13 13:51:48 UTC

3840/1.75 = 2194.28571 which is not an integer, so the panel on the right screen leaks one pixel to the left screen. This can't be easily fixed in Plasma 5 as the API uses int not double to set struts.

Comment 3 Rafael Linux User 2023-10-13 20:04:56 UTC

(In reply to Fushan Wen from comment #2)
> 3840/1.75 = 2194.28571 which is not an integer, so the panel on the right
> screen leaks one pixel to the left screen. This can't be easily fixed in
> Plasma 5 as the API uses int not double to set struts.

Perhaps, in my ignorance, the result could be rounded down, but I don't know what other implications it might have.