Bug 463897

Summary: Kinetic Scrolling [Wishlist]
Product: [Applications] dolphin Reporter: tim <imagesfromobjects>
Component: generalAssignee: Dolphin Bug Assignee <dolphin-bugs-null>
Status: RESOLVED DUPLICATE    
Severity: wishlist CC: bugs.kde.org, kde, kfm-devel, linus.kardell, miranda, norbertzpilicy
Priority: NOR    
Version: 22.08.3   
Target Milestone: ---   
Platform: Kubuntu   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description tim 2023-01-05 20:58:48 UTC 
SUMMARY:
It would be very nice if Dolphin were to implement smooth / kinetic scrolling. It has become the standard on almost every OS and file manager, yet it is conspicuously missing from Dolphin. It seems to be missing from QT apps in general, but for starters, I would LOVE to see it on Dolphin, being that is where many folks like myself will spend a majority of their time. 

STEPS TO REPRODUCE:
1. Open Dolphin (or any QT app) on a device using a touchpad.
2. Open a folder with a good number of files (e.g. /bin/) 
3. Using two-finger scrolling, swipe quickly downward to get to files that are beyond the current view.

OBSERVED RESULT:
Movement stops abruptly, giving the impression of jerkiness and sluggishness

EXPECTED RESULT:
Movement should continue smoothly onward after the swipe has ended, employing inertia, eventually slowing down to a standstill with "friction", otherwise it should be stopped abruptly if the user places two fingers down again, or swipes in another direction.  This would give a much more "organic" feel to browsing files, and would improve the user experience drastically.


SOFTWARE/OS VERSIONS:
Operating System: Kubuntu 22.10
KDE Plasma Version: 5.26.5
KDE Frameworks Version: 5.101.0
Qt Version: 5.15.6
Kernel Version: 5.15.0-10056-tuxedo (64-bit)
Graphics Platform: X11 (and Wayland)



ADDITIONAL INFORMATION
It would be EXTRA wonderful, if - in true KDE fashion - this were a user-configurable setting. I realize that some people may not want it at all, and it would be somewhat difficult to arrive at a "default" for length of time for the scrolling to slow down due to different touch pads and monitors, so even if it weren't exposed through Settings, it would be lovely to have a config file where one could tweak pixel scroll distance / friction etc.

Thanks for your time.
Comment 1 Linus Kardell 2023-01-22 22:50:59 UTC 
This is something that we do have on X11, at least with Synaptics. But on Wayland, we have to use libinput, which leaves it to the client to implement kinetic scrolling, which KDE applications (or, rather, Qt) currently do not. So I would consider this a Wayland regression.
Comment 2 Norbert 2023-03-17 07:52:23 UTC 
Also other apps don't have it. Probably GTK ones too. I'd implement it as a system-wide solution. Just like "reverse scrolling direction" setting. It's naive to think every single program on your system is going to implement kinetic scrolling. And imagine setting acceleration factor for all of them individually... It is surely a regression from Xorg+Synaptics experience.
Comment 3 David Edmundson 2024-11-01 15:34:03 UTC 

*** This bug has been marked as a duplicate of bug 76082 ***
Comment 4 Linus Kardell 2024-11-09 20:17:33 UTC 
That issue seems to be mostly about smooth scrolling (and originally about X11). There are some mentions there of kinetic scroll (in 2010-2011), but isn't kinetic scroll on libinput a separate issue? Richard Hartmann seemed to think so there.

>Also other apps don't have it

Firefox does, though that's the only one I've found.