Smooth scrolling works with touchpad, but not with mouse wheel on KDE

gunjah292 · 2019-02-24 10:38:00

I realized that smooth scrolling works with the touchpad, but not with my Logitech mouse. I don't see any setting in the Plasma settings or kwinrc.

Why could this be?

Last edited by gunjah292 (2019-02-24 10:44:56)

lsr · 2019-02-26 20:51:16

Could you clarify what you mean by "smooth scrolling" here?

Touchpads can provide high resolution scrolling events. That is, they can provide many tiny scroll events per second which are translated directly into scroll of your view (provided it can keep up). Qt5 and gtk3 applications, for instance, support these events natively and their provided scrolling widgets will Do The Right Thing automatically.

The great majority of mice, however, provide granular scroll events in the old style much less frequently that translate to some number of lines or pixels scrolled. There is/was a feature to essentially delay scrolling by animating the transition between these larger blocks often called "smooth scrolling" which was originally added to web browsers circa the cold war. I'm not aware of where this feature might still live. Because it is essentially adding a delay to your wishes it is contentious, and some people (myself included) hate it with passion, but it remains in some places, e.g. some browsers.

gunjah292 · 2019-03-03 15:28:02

Well, the smooth scrolling (with very small steps) works with browser and the mouse, but not with qt5 and gtk3 applications. This should be an easy thing to fix, so I don't really get why it still perists.

digitalone · 2019-03-05 08:32:17

gunjah292 wrote:

I realized that smooth scrolling works with the touchpad, but not with my Logitech mouse. I don't see any setting in the Plasma settings or kwinrc.
Why could this be?

Have you synaptics touchpad driver installed?

gunjah292 · 2019-03-05 09:30:17

@digitalalone: No I use libinput

digitalone · 2019-03-06 11:38:22

Rather than synaptics, libinput has no features like coasting, so smooth scrolling has to be implemented by the apps. If qt5 and gtk3 apps don't have it, there's nothing you can do.

V1del · 2019-03-06 11:48:22

Logitech high resolution timers have just been implemented in the 5.0 kernel on the kernel level. It will be a while till applications/userspace is updated to properly react to this.

http://who-t.blogspot.com/2018/12/high- … ng-on.html

At minimum, this patchset will have to be part of a libinput release. Then it might even be configurable there, without the need to change other userspace.

Once relevant pieces are in place this should provide similar behaviour to what's already implemented in touchpads.

Last edited by V1del (2019-03-06 11:58:32)

gunjah292 · 2019-03-08 18:26:12

@V1del: Great I just installed the new kernel

Arch Linux

#1 2019-02-24 10:38:00

Smooth scrolling works with touchpad, but not with mouse wheel on KDE

#2 2019-02-26 20:51:16

Re: Smooth scrolling works with touchpad, but not with mouse wheel on KDE

#3 2019-03-03 15:28:02

Re: Smooth scrolling works with touchpad, but not with mouse wheel on KDE

#4 2019-03-05 08:32:17

Re: Smooth scrolling works with touchpad, but not with mouse wheel on KDE

#5 2019-03-05 09:30:17

Re: Smooth scrolling works with touchpad, but not with mouse wheel on KDE

#6 2019-03-06 11:38:22

Re: Smooth scrolling works with touchpad, but not with mouse wheel on KDE

#7 2019-03-06 11:48:22

Re: Smooth scrolling works with touchpad, but not with mouse wheel on KDE

#8 2019-03-08 18:26:12

Re: Smooth scrolling works with touchpad, but not with mouse wheel on KDE

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