Created attachment 162773 [details] Comparison between 5.27 and 6 on horizontal panel SUMMARY When using panel spacers to center an applet on a panel, the applet will be in the center of the two panel spacers, instead of in the center of the panel, like in Plasma 5.27 STEPS TO REPRODUCE 1. Put at least two applets on a panel 2. Center one of them using panel spacers 3. Set those spacers to Set Flexible Size OBSERVED RESULT The applet is centered in the free space where are the spacers All spacers have the same length EXPECTED RESULT Plasma 5.27 behavior: The applet is in the middle of the panel Spacers may not have the same length SOFTWARE/OS VERSIONS Linux/KDE Plasma: openSUSE Tumbleweed (available in About System) KDE Plasma Version: 5.27.80 -> Master - build using kdesrc-build KDE Frameworks Version: 5.240.0 Qt Version: 6.6.0 ADDITIONAL INFORMATION I think this is regression between 5.27 and 6 Added image showing comparison between 5.27 and 6 This happens with any applet being centered, not only Task Manager like in the image Also tested in Neon Unstable inside a virtual machine, showing the same result
Created attachment 162774 [details] Comparison between 5.27 and 6 on vertical panel
Created attachment 162775 [details] The bug on Neon-Unstable
Can reproduce.
A possibly relevant merge request was started @ https://invent.kde.org/plasma/plasma-workspace/-/merge_requests/3465
Git commit 09893ea151923979c25f0b85c0d2bf83f76772f1 by Nate Graham, on behalf of Alex Čižinský. Committed on 02/11/2023 at 18:52. Pushed by ngraham into branch 'master'. Fix applet centering by spacers Prior to this fix, when using spacers to center an applet in a panel, the applet would be centered in the available space. However, the desired behavior is for the applet to be centered in the middle of the panel, just as it was in Plasma 5.27. The reason of this bug are the API changes in KF6. Prior to this fix, the code would try to call nonexistent properties, resulting in the optimalSize property being NaN. M +2 -2 applets/panelspacer/package/contents/ui/main.qml https://invent.kde.org/plasma/plasma-workspace/-/commit/09893ea151923979c25f0b85c0d2bf83f76772f1