Created attachment 65950 [details] Screenshot showing the missing thumbnails of passive tabbed windows. Version: 4.7.3 (using KDE 4.7.3) OS: Linux When resizing a group of tabbed windows, kwin doesn't provide window thumbnails for the background windows of the tabbing group unless these windows are brought to the foreground once. Reproducible: Always Steps to Reproduce: 1. Open multiple windows 2. Tab them to a single window 3. Look at the thumbnails e.g. by hovering the window entry in the task list 4. Resize the window which contains the tab-group 5. Look again at the thumbnails Actual Results: #3 - Thumbnails are shown as expected #5 - Only the thumbnail of the currently active tab is shown (see attached screenshot) Expected Results: I'd expect kwin to also provide thumbnails for the "passive" windows of a tab group after resizing the tab group. This isn't a specific issue of the plasma task applet, as it also happens when using the "IconTasks" applet.
"kcmshell4 kwincompositing", 3rd tab, "keep window thumbnails:" -> "always (breaks minimization)" Be aware that "breaks minimization" literally means "breaks minimization" - the windows are never really "minimized" but just taken off screen. This can lead to issues with various clients. Neither X11 not NETWM currently provide a sufficient solution but the entire thing is implicitly fixed by the wayland architecture.