Bug 461080

Summary:	Create thumbnails for the present windows effect when compositing is activated
Product:	[Plasma] kwin	Reporter:	Alex <allo>
Component:	effects-present-windows	Assignee:	KWin default assignee <kwin-bugs-null>
Status:	REPORTED ---
Severity:	minor	CC:	nate
Priority:	NOR
Version First Reported In:	6.2.3
Target Milestone:	---
Platform:	Debian testing
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Alex 2022-10-27 18:15:53 UTC

SUMMARY
The present windows effect shows empty previews when compositing was disabled and now is enabled, until each window was actived once.

STEPS TO REPRODUCE
1. Disable compositing, e.g., with shift-alt-F12
2. Enable compositing, e.g., with shift-alt-F12
3. Activate the present windows effect

OBSERVED RESULT
The thumbnails are empty, for both new windows and windows that had a thumbnail before compositing was disabled.

EXPECTED RESULT
After enabling compositing, the window thumbnails should be refreshed, such that the present window effect and other effects with window thumbnails do not show empty thumbnails.

SOFTWARE/OS VERSIONS
Operating System: Debian GNU/Linux
KDE Plasma Version: 5.26.0
KDE Frameworks Version: 5.98.0
Qt Version: 5.15.4
Graphics Platform: X11

Comment 1 Alex 2022-11-13 10:45:18 UTC

Why I would like to have this is, that the previews also get discarded when the computer is suspended. This may be related to using the nvidia driver, or a bug in KWin, but compositing is active (or activated again) when the computer wakes up and only the preview images are missing.