Mouse scroll does not work in Qt applications

Axon · 2018-01-10 19:49:25

On one of my Arch machines the mouse scroll stopped working in Qt5 applications. Qt4, GTK2 and GTK3 scroll fine. The problem occurs even for a test user with blank home directory, and does not depend on the Graphical environment (tried KDE, Openbox and i3). But if I send the scroll wheel events with xdotool instead of my physical mouse, it works.
What happened and how do I fix it?

h4tr3d · 2026-01-20 00:23:39

Same issue back in 2026. Qt 6.10. Sounds like issue happens after series of the Sleep/Resume operations. Non-Qt application still continue to handle Mouse Wheel events. Application restart restores Wheel work. But it annoying me. Any WA/suggestions?

seth · 2026-01-20 08:13:53

Wheel specifically, other mouse buttons work?
The wheel probably still works but sends low resolution event values for high resolution events, check libinput before and after whether it switches from 15/120 to 1/120
https://wayland.freedesktop.org/libinpu … hires.html
https://wayland.freedesktop.org/libinpu … l-api.html

h4tr3d · 2026-01-20 09:01:37

seth wrote:

Wheel specifically, other mouse buttons work?

Hmmm. Yes, other mouse buttons stop work correctly too. Left Mouse Button works like toggle: Context menu shown and hides immediately.

The wheel probably still works but sends low resolution event values for high resolution events, check libinput before and after whether it switches from 15/120 to 1/120
https://wayland.freedesktop.org/libinpu … hires.html
https://wayland.freedesktop.org/libinpu … l-api.html

Not sure. I expect, that low resolution values at least should do some visible work for scrolling.

BTW, X11 session used.

seth · 2026-01-20 09:05:21

Yes, other mouse buttons stop work correctly too. Left Mouse Button works like toggle: Context menu shown and hides immediately.

So "no" - seems some button or key state got stuck, but if restarting the application unsticks it, it has to be a local state.

1. what applications specifically
2. how do you suspend the system (shortcut?)

h4tr3d · 2026-01-20 09:14:14

seth wrote:

So "no" - seems some button or key state got stuck, but if restarting the application unsticks it, it has to be a local state.

It sounds like Qt6 related. Or, maybe, KDE related. When issue occurred all started Qt6 apps stops react to Wheel, at least: Dolphin, Okular, Qt Creator. Panel (PlasmaShell) sounds like also stop responds to mouse interactions.

1. what applications specifically

Framework specifically...

2. how do you suspend the system (shortcut?)

Sleep button on the my Thinkpad P15gen2. Handles by KDE by default.

seth · 2026-01-20 12:31:49

The screen probably also locks?
What if you disable that (only sleep but no screenlock)?

Many applications being affected sounds less like an internal state gets messed up but if it was the input device, restarts (you only restart the affected process, not the entire session?) would not work

h4tr3d · 2026-01-21 01:34:22

seth wrote:

The screen probably also locks?

Yes.

What if you disable that (only sleep but no screenlock)?

Hmmm... Will try. But if it is true, only screen locks without sleep also should work.

Many applications being affected sounds less like an internal state gets messed up but if it was the input device, restarts (you only restart the affected process, not the entire session?) would not work

There is set of issue reports to the Qt tracker with same descriptions. But all of them marks as resolved.

seth · 2026-01-21 09:48:47

There is set of issue reports to the Qt tracker

For instance?

only screen locks without sleep also should work.

Theoretical events: locker grabs input, system sleeps, wakes, outputs get re-attached, locker releases wrong devices.

Though if

stops react to Wheel, at least: Dolphin, Okular, Qt Creator. Panel (PlasmaShell) sounds like also stop responds to mouse interactions

the predominant problem is the wheel and the mouse otherwise fails in isolated cases only the switch from a hi-res to low-res device is more likely - check what events "libinput debug-events" generates before and after such incident.

V1del · 2026-01-21 19:50:11

Since seth engaged and there has not been much content in the OP I'll leave this for now, but please pay attention to the dates and don't necrobump 8 year old threads. https://wiki.archlinux.org/title/Genera … bumping%22

Arch Linux

#1 2018-01-10 19:49:25

Mouse scroll does not work in Qt applications

#2 2026-01-20 00:23:39

Re: Mouse scroll does not work in Qt applications

#3 2026-01-20 08:13:53

Re: Mouse scroll does not work in Qt applications

#4 2026-01-20 09:01:37

Re: Mouse scroll does not work in Qt applications

#5 2026-01-20 09:05:21

Re: Mouse scroll does not work in Qt applications

#6 2026-01-20 09:14:14

Re: Mouse scroll does not work in Qt applications

#7 2026-01-20 12:31:49

Re: Mouse scroll does not work in Qt applications

#8 2026-01-21 01:34:22

Re: Mouse scroll does not work in Qt applications

#9 2026-01-21 09:48:47

Re: Mouse scroll does not work in Qt applications

#10 2026-01-21 19:50:11

Re: Mouse scroll does not work in Qt applications

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