Bug 508946

Summary: (Rebound) tablet rings can "flicker" between two states easily
Product: [Plasma] kwin Reporter: Joshua Goins <josh>
Component: inputAssignee: Joshua Goins <josh>
Status: CONFIRMED ---    
Severity: normal CC: duha.bugs
Priority: NOR    
Version First Reported In: 6.4.80   
Target Milestone: ---   
Platform: Compiled Sources   
OS: Linux   
Latest Commit: Version Fixed/Implemented In:
Sentry Crash Report:

Description Joshua Goins 2025-08-30 17:39:35 UTC 
SUMMARY
I'm about to leave for Akademy, so I can't fix this immediately but plan to before 6.5's release.

This is very repeatable, not just by holding down your finger and slowly moving but also during "fast swipes" where you complete many rotations at once. You can notice - for example, in Krita's canvas preview - that the zooming "stutters" like its quickly pressing and unpressing the bound keybind. (Haven't debugged to see if it's actually doing that yet.)

I'm certain this is because of my terrible rotation detection code :-)

STEPS TO REPRODUCE
1. Bind a tablet ring to two keybinds, e.g. zooming in an application
2. Complete "rotations" (depending on the speed you set) and notice the odd stutter here or there

OBSERVED RESULT
It stutters a bit like the rebind can't decide whether it's a full "rotation" or not.

EXPECTED RESULT
It doesn't obviously stutter.

SOFTWARE/OS VERSIONS
KDE Plasma Version: Plasma 6.5 compiled sources (kwin: 83c8091da48a7033b5c3617620c7eea3571bec2f)
Qt Version: 6.9.1