Bug 459804 - Mouse cursor is hidden windows when crossing the screen over a window on both screens
Summary: Mouse cursor is hidden windows when crossing the screen over a window on both...
Status: REPORTED
Alias: None
Product: kwin
Classification: Plasma
Component: wayland-generic (other bugs)
Version First Reported In: 5.25.5
Platform: openSUSE Linux
: NOR normal
Target Milestone: ---
Assignee: KWin default assignee
URL:
Keywords:
Depends on:
Blocks:
 
Reported: 2022-09-28 20:57 UTC by Luiz Angelo De Luca
Modified: 2022-10-28 12:41 UTC (History)
0 users

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


Attachments
Photo of a hidden cursor (79.35 KB, image/jpeg)
2022-09-29 23:31 UTC, Luiz Angelo De Luca
Details

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Description Luiz Angelo De Luca 2022-09-28 20:57:00 UTC
SUMMARY

If I put any non-Qt/Kde window crossing two screens and move the mouse over it, the cursor is hidden when it crosses the screen border until it reaches that window border. It does not reappears if I simply move back to the old screen. The same does not happen with Qt apps. Mouse even like click, does still work (but it does not make the mouse cursor back).

1. configure side-by-side screen
2. open xterm
3. put the xterm screen over the border between the two screens
4. move the mouse cursor over the xterm window and across the screen border

OBSERVED RESULT

5. mouse cursor is hidden.

EXPECTED RESULT

5. mouse cursor should be still there as usual.

SOFTWARE/OS VERSIONS
Linux/KDE Plasma: OpenSUSE Tumbleweed 20220917
KDE Plasma Version:  5.25.5
KDE Frameworks Version: 5.98.0
Qt Version: 5.15.5

ADDITIONAL INFORMATION
Comment 1 Vlad Zahorodnii 2022-09-29 07:27:47 UTC
I can't reproduce it.
Comment 2 Luiz Angelo De Luca 2022-09-29 23:31:44 UTC
Created attachment 152509 [details]
Photo of a hidden cursor

I activated the "Follow mouse effect" to show that the mouse cursor was there and externally took a picture. I tried to record the screen or that a screenshot but the mouse was there.

My multiscreen is not a simple side-by-side. The left monitor is rotated, with extra border over and under the right monitor. There is no screen overlap.
Comment 3 Vlad Zahorodnii 2022-09-30 09:01:09 UTC
Can you post the output of `qdbus org.kde.KWin /KWin supportInformation`?
Comment 4 Luiz Angelo De Luca 2022-09-30 16:54:44 UTC
(In reply to Vlad Zahorodnii from comment #3)
> Can you post the output of `qdbus org.kde.KWin /KWin supportInformation`?

https://invent.kde.org/-/snippets/2363
Comment 5 Vlad Zahorodnii 2022-10-03 08:51:07 UTC
Hmm, I see nothing "weird" about your setup. A shot in the dark:

- can you run kwin with KWIN_DRM_SW_ROTATIONS_ONLY=1 environment variable set? e.g. you could put it in /etc/environment and reboot the computer

- if the issue is still reproducible, can you try setting KWIN_FORCE_SW_CURSOR=1 too?
Comment 6 Luiz Angelo De Luca 2022-10-13 17:31:24 UTC
(In reply to Vlad Zahorodnii from comment #5)
> Hmm, I see nothing "weird" about your setup. A shot in the dark:
> 
> - can you run kwin with KWIN_DRM_SW_ROTATIONS_ONLY=1 environment variable
> set? e.g. you could put it in /etc/environment and reboot the computer
> 
> - if the issue is still reproducible, can you try setting
> KWIN_FORCE_SW_CURSOR=1 too?

With KWIN_DRM_SW_ROTATIONS_ONLY=1, the issue is still there
With KWIN_FORCE_SW_CURSOR=1, it worked as expected. 

I tested the KWIN_FORCE_SW_CURSOR keeping KWIN_DRM_SW_ROTATIONS_ONLY set. Is it worth it to test it without KWIN_DRM_SW_ROTATIONS_ONLY?

The software cursor now draws a darker region over the konsole black (with a little bit transparent) background for a second while moving when konsole when the window under it is mostly white. I don't know how software cursors works today but in the old times, we used to copy the region where the cursor would appear, draw, before drawing the next cursor position, erase it pasting the copied region. It looks like kwin copied konsole region (or asked konsole to do it) without considering the transparency effect, just like the spectacle ignores that same effect while taking a screen shot.
Comment 7 Bug Janitor Service 2022-10-28 05:02:25 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 8 Luiz Angelo De Luca 2022-10-28 12:41:59 UTC
Cleared needsinfo