Bug 402862

Summary: Window thumbnails don't have good integration with Qt Quick
Product: [Plasma] kwin Reporter: Vlad Zahorodnii <vlad.zahorodnii>
Component: generalAssignee: KWin default assignee <kwin-bugs-null>
Status: RESOLVED FIXED    
Severity: normal    
Priority: NOR    
Version First Reported In: git master   
Target Milestone: ---   
Platform: Other   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:
Attachments: Screenshot

Description Vlad Zahorodnii 2019-01-04 15:38:30 UTC
Created attachment 117282 [details]
Screenshot

SUMMARY
Each WindowThumbnailItem is painted above its corresponding window (with compositing being on), see Scene::paintWindow.

Because of that, we're not able to use effects provided by Qt Quick or just paint a badge above a thumbnail to mark it as selected.

In addition to that, painting window thumbnails directly onto the screen causes visual artifacts when using effects like the Sliding Popups, see the attached screenshot.

SOFTWARE/OS VERSIONS
KDE Plasma Version: 5.14.80
KDE Frameworks Version: 5.53
Qt Version: 5.12
Comment 1 Martin Flöser 2019-01-04 16:32:20 UTC
The main reason for this is that on X11 KWin and Qt could not share the OpenGL context. On Wayland we could get KWin's texture into QtQuick, but it would mean that we need different code paths.