Bug 469734

Summary:	Kwin's "Switch to window to the left/right" do not work across screens that aren't the same size
Product:	[Plasma] kwin	Reporter:	Oded Arbel <oded>
Component:	general	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	normal	CC:	60f31543-f82f-492a-8430-25db5521568b, natalie_clarius, nate
Priority:	NOR
Version First Reported In:	5.27.5
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:
Attachments:	A screencast showing the problem

Description Oded Arbel 2023-05-14 09:06:16 UTC

SUMMARY
On my setup, I have 2 vertical screens and one horizontal screen that is positioned to the right at about the center line of the vertical screens. I use the "Switch to window to the left/right" keyboard shortcuts a lot to get to specific window.

This used to work well, on Wayland (I haven't tested with X11 recently, but it used to work well there as well), up until sometime during 5.27.

Now, if I want to switch from a maximized window on a vertical screen to a window on the horizontal screen, the "switch to window" shortcuts refuse to traverse the boundary between the vertical screens and horizontal screen, though I can get to the horizontal screen by going in through the left - wrapping around to come in to the horizontal screen from the far side.

STEPS TO REPRODUCE
1. Using a setup of a vertical screen (or two) on the left side, and a horizontal screen on the right side, have maximized windows on all screens.
2. Select the window on the left most screen.
3. Press the "switch to window to the right" shortcut (Meta+Alt+Right) repeatedly until you get to the window on the right most screen.

OBSERVED RESULT
Kwin will not switch to the right most screen.

EXPECTED RESULT
Kwin should eventually activate the window on the right most screen.

The reverse also doesn't work - when selecting the window on the horizontal screen, it is not possible to use the "Switch to window to the left" shortcut to go to the vertical screen.

SOFTWARE/OS VERSIONS
Operating System: KDE neon Testing Edition
KDE Plasma Version: 5.27.5
KDE Frameworks Version: 5.106.0
Qt Version: 5.15.9
Kernel Version: 6.2.0-20-generic (64-bit)
Processors: 8 × Intel® Core™ i7-7820HQ CPU @ 2.90GHz
Memory: 31.2 GiB of RAM
Graphics Processor: Mesa Intel® HD Graphics 630

ADDITIONAL INFORMATION
Screen cast showing the issue will be attached shortly.

I found that if the window on the vertical screen is not maximized, then the "switch to window to the right" does go to the horizontal screen, but it still won't go back left - regardless whether the window on the horizontal screen is maximized or not.

Comment 1 Oded Arbel 2023-05-14 09:09:56 UTC

Created attachment 158933 [details]
A screencast showing the problem

I'm using a Breeze dark window decoration so it should be easy to figure out which window is active, and the kscreen KCM module is also open so we can see the screen setup.

In this cast I'm showing how the "switch to window" shortcuts work well between the vertical screens, but can't be used to go right to the horizontal screen, finally showing that we can go left and wrap around to the horizontal screen.

I tried to also show that we can't use "switch to window to the left" to get from the horizontal screen to the vertical screen, but the video was cut short for some reason.