Scrolling in the system tray on any icon except the 'battery and brightness' icon switches desktops. On the 'battery and brightness' icon, it shows the expected behaviour of changing brightness. Steps to reproduce: Scroll with the mouse wheel while the cursor is on any system tray icon other than the 'battery and brightness' icon. Expected behaviour: Scrolling should either perform no action, or an action depending on the icon (change volume, brightness etc.). Problem appears in versions 5.8.3 and 5.8.4 (Not sure which one to mark on report). If it helps, I could fix the problem by downgrading the 'plasma-workspace' [https://www.archlinux.org/packages/extra/x86_64/plasma-workspace/] package to version 5.8.2-1. Was able to reproduce in a different user, and in a VM.
*** Bug 373042 has been marked as a duplicate of this bug. ***
it doesn't seem to happen on a clean setup. on an old session i had the wheel plugin erroneously setted for panel type containments, so in some cases it appears to be possible that this wrong setting gets written in the config file
(In reply to Marco Martin from comment #2) > it doesn't seem to happen on a clean setup. > on an old session i had the wheel plugin erroneously setted for panel type > containments, so in some cases it appears to be possible that this wrong > setting gets written in the config file I created a new user, and the problem doesn't occur in it. Can you give me some pointers on which config files I should be looking at?
So after reading Marco's comment above I decided to have a look at Plasma's configuration files, .config/plasma-org.kde.plasma.desktop-appletsrc in particular, and I found this bit: [ActionPlugins][129] MidButton;NoModifier=org.kde.paste RightButton;NoModifier=org.kde.contextmenu wheel:Vertical;NoModifier=org.kde.switchdesktop I stopped plasmashell, removed the `wheel:Vertical;NoModifier=org.kde.switchdesktop` line and started plasmashell again, and the wheel no longer has an effect on the system tray icons or arrow or the dead space between icons. Not sure how this configuration ended up here in the first place. I thought it could be related to the Mouse Actions tab in the desktop configuration, but adding an action to switch desktops on wheel presses didn't seem to affect the system tray at all. Note that before editing the config file I had tried removing and readding the system tray widget, and adding a new panel using the Default Panel preset; neither made a difference.
The issue is that the wheel event is passed to the lower widget (in this case the desktop). The systray should always accept the wheel event to prevent this. See related bug.
https://phabricator.kde.org/R120:d1ea67c1fcf03dc6365eaf62b3d815533267292f
*** Bug 372812 has been marked as a duplicate of this bug. ***
*** Bug 373331 has been marked as a duplicate of this bug. ***
*** Bug 373712 has been marked as a duplicate of this bug. ***