Bug 512325

Summary:	“Hold down middle button and move mouse to scroll” should allow user to specify button
Product:	[Applications] systemsettings	Reporter:	Carl Miller Jr. <thehalian>
Component:	kcm_mouse	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	REPORTED ---
Severity:	wishlist	CC:	duha.bugs, justin, natalie_clarius
Priority:	NOR	Keywords:	accessibility
Version First Reported In:	6.5.1
Target Milestone:	---
Platform:	CachyOS
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Carl Miller Jr. 2025-11-19 03:04:39 UTC

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SUMMARY
I use an Elecom HUGE trackball and, in most of my OS setups, I map its Fn3 button (xinput button 12) to enable using the ball as a two-dimensional scroll wheel. However, there is no way to do this in a Wayland-based KDE setup. I can set the middle mouse button to enable ball scroll mode when held, but then it uses its usual function as the middle mouse button, which is a show-stopper for me.

STEPS TO REPRODUCE
1. Attempt to run the xinput commands to set up button 12 as a ball scroll button
2. Look around in the System Settings menu for relevant options
3. Give up or sacrifice your middle mouse button to ball scroll mode

OBSERVED RESULT
The only way I can set up ball scroll mode in KDE under Wayland is to sacrifice my middle mouse button.

EXPECTED RESULT
There's a way to use any button I want as the ball scroll button in KDE under Wayland.

SOFTWARE/OS VERSIONS
Linux: 6.17.7-5
KDE Plasma Version: 6.5.2-1.1
KDE Frameworks Version: 6.19.0-1.1
Qt Version: 6.10.0-3

ADDITIONAL INFORMATION
This could also be a boon to accessibility users, as a trackball is larger and easier to manipulate than a scroll wheel or its underlying middle mouse button.