Bug 355410 - Scroll speed of QML scroll area is too slow with the xf86-input-libinput driver
Summary: Scroll speed of QML scroll area is too slow with the xf86-input-libinput driver
Status: RESOLVED DUPLICATE of bug 375069
Alias: None
Product: libplasma
Classification: Frameworks and Libraries
Component: libplasmaquick (show other bugs)
Version: unspecified
Platform: Arch Linux Linux
: NOR normal
Target Milestone: ---
Assignee: Marco Martin
URL:
Keywords:
: 358765 372971 (view as bug list)
Depends on:
Blocks:
 
Reported: 2015-11-16 07:08 UTC by Ukyoi
Modified: 2017-07-13 09:02 UTC (History)
35 users (show)

See Also:
Latest Commit:
Version Fixed In:


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Description Ukyoi 2015-11-16 07:08:17 UTC
Please forgive me if I reported the bug in a wrong place since I'm not sure if Plasma should to be blame.

Qt 5 can use libinput to provide smooth scrolling with my Trackpoint. While the scroll speed with QML is a lot slower than which in QtWidget scroll area. It's bearable if I use evdev (since the minimum scroll lines is 3 with the default mouse config in systemsettings). But with libinput, the speed is too slow to locate easily.

Thanks for reading this report.

Reproducible: Always

Steps to Reproduce:
1. Find a QML based plasmoid that has a scroll area (e.g. kickoff).
2. Scroll it with trackpoint.

Actual Results:  
It scrolls a lot slower than which in QtWidget scroll area.

Expected Results:  
The speed should be the same as which in QtWidget scroll area.
Comment 1 Ukyoi 2015-11-16 07:12:08 UTC
Please also refer to this post:
https://forum.kde.org/viewtopic.php?f=289&t=127279
Comment 2 Christian Stadelmann 2016-01-11 16:02:58 UTC
Same issue here with plasma 5.5.3 on Fedora 23.

I'm also not sure that Plasma is to blame since this issue is also present in dolphin and kcm. Is this a bug in Qt?

Expected number of lines scrolled, working fine in:
* Qt5 applications like ksysguard 5.5.3, kwrite 15.08.3, konsole 15.08, most parts of KDE control center, KGpg
* Gtk2 and Gtk3 applications

Scrolls less than a single line per scroll wheel move in:
* Dolphin 15.08.1: Places panel, file list (central component), folders panel, but NOT terminal panel
* Plasma application overview (Application Dashboard in kdeplasma-addons)
* Plasma application starter
* Plasma indicator for removable devices (enable showing all devices in preferences to have enough devices to list)
* KDE control center, section window decoration designs
Comment 3 Rémi Verschelde 2016-02-05 17:15:31 UTC
I have the exact same issue as Christian in comment 2, though I can't confirm if it's really the same one as comment 0. Many applications work fine but Dolphin and the application launcher have unbearably slow scrolling speeds.

Testing on Mageia Cauldron (6) with Plasma 5.5.4, Dolphin 15.12.1, Qt 5.6.0 beta.
Comment 4 Ali Hakki 2016-04-01 11:20:15 UTC
Plasma-Desktop 5.6.1 and the problem continues.
on arch linux 
if i install xf86-input-libinput
    plasma5 mouse scroll is too slow. problem..
Comment 5 Rex Dieter 2016-04-01 14:07:36 UTC
marking confirmed.  I strongly suspect this to be a Qt5 issue though (not a kde.org one)
Comment 6 Dmitrii Chermnykh 2016-05-08 11:26:27 UTC
*** Bug 358765 has been marked as a duplicate of this bug. ***
Comment 7 H.H. 2016-06-09 09:47:44 UTC
I have the same problem in dolphin scrolling the files (detail-list-view): one scroll-wheel event scrolls about half a row.

In KDE-Settings I have set it to 3 rows.

No such problems in konsole, mysql-query-browser (gtk2), eclipse (java-swt (gtk3))

Problem appeared since my last update (opensuse tumbleweed), only some minor kde5/qt5 upgrade.
Comment 8 Ezequiel Ortiz Rossner 2016-06-11 16:21:52 UTC
Me too have this issue with mouse slow scrolling speed in dolphin and application launcher in Manjaro Linux Plasma 5, more info here: https://forum.manjaro.org/t/mouse-scrolling-speed-very-slow-in-dolphin-application-launcher/3853
Comment 9 Patrick Peronny 2016-06-18 10:18:00 UTC
Same issue on Debian - Plasma 5.6.4
Comment 10 Sebastian Hörberg 2016-06-28 10:24:11 UTC
This also occurs on Fedora 24. I can confirm this happens in a similar vein to comment 2 and comment 8.

Let me know if there is further information I can provide.

Fedora 24: Plasma 5.6.5, libinput 1.3.3, Dolphin 16.04.1, Qt 5.6.0
Comment 11 Robby Engelmann 2016-07-11 09:16:12 UTC
I can confirm for openSUSE Tumbleweed, Qt 5.6.1, Frameworks 5.24, Plasma 5.7 and KDE Apps 16.04.2
Comment 12 Roman 2016-07-11 09:55:21 UTC
It can be fixed by replacing xf86-input-libinput to xf86-input-evdev(Arch Linux). Probably the same solution on other distros, but with another package names
Comment 13 Robby Engelmann 2016-07-11 10:12:48 UTC
I would not call that "fixed". One can workaround that problem by replacing, but it should work with libinput.
Comment 14 varlesh 2016-08-07 02:57:18 UTC
I confirm this. Delete xf86-input-libinput and install xf86-input-evdev solved problem.
Comment 16 Wulf 2016-10-03 22:57:48 UTC
"It can be fixed by replacing xf86-input-libinput to xf86-input-evdev(Arch Linux"

I've also Arch Linux and I've installed xf86-input-evdev; but however I have this problem for the left sidebar in dolphin (not for the main window), but only there. I could not find another application with this problem
Comment 17 Marco Scarpetta 2016-10-08 09:01:58 UTC
I have the same problem on Arch Linux with xf86-input-evdev installed.

(In reply to Wulf from comment #16)
> "It can be fixed by replacing xf86-input-libinput to xf86-input-evdev(Arch
> Linux"
> 
> I've also Arch Linux and I've installed xf86-input-evdev; but however I have
> this problem for the left sidebar in dolphin (not for the main window), but
> only there. I could not find another application with this problem
Comment 18 Dmitrii Chermnykh 2016-10-08 09:28:28 UTC
"problem on Arch Linux with xf86-input-evdev " you needs manually uninstall xf86-input-libinput and it should work
Comment 19 Wulf 2016-10-08 09:39:42 UTC
@chermnykh2001: xf86-input-libinput is not installed, but I have this problem for dolphin left side panel; only there
Comment 20 Ben Bullard 2016-11-05 01:46:37 UTC
(In reply to Rex Dieter from comment #5)
> marking confirmed.  I strongly suspect this to be a Qt5 issue though (not a
> kde.org one)

I'm wondering if this has been reported to QT folks?

https://www.qt.io/developers/

I'm not a developer and don't have an account there.
Comment 21 Elvis Angelaccio 2016-11-16 18:49:25 UTC
Changing the title as libinput on Wayland is *not* affected (and neither is xf86-input-evded, as already reported).
Comment 22 Wulf 2016-11-16 21:02:52 UTC
for me (and obviously other users too, comment 17) xf86-input-evdev is affected at dolphin left side panel

should I write a new bug report for this?
Comment 23 Elvis Angelaccio 2016-11-16 21:38:42 UTC
(In reply to Wulf from comment #22)
> for me (and obviously other users too, comment 17) xf86-input-evdev is
> affected at dolphin left side panel
> 
> should I write a new bug report for this?

There is already one: https://bugs.kde.org/show_bug.cgi?id=365968

QML scrolling with evdev works for me.
Comment 24 Elvis Angelaccio 2016-11-17 13:10:57 UTC
Reported upstream: https://bugreports.qt.io/browse/QTBUG-57186
Comment 25 Christoph Feck 2016-11-27 03:31:55 UTC
*** Bug 372971 has been marked as a duplicate of this bug. ***
Comment 26 Guo Yunhe 2017-03-22 07:32:01 UTC
Is it a bug of Qt or KDE?
Comment 27 Elvis Angelaccio 2017-03-22 08:18:35 UTC
(In reply to Guo Yunhe (郭云鹤) from comment #26)
> Is it a bug of Qt or KDE?

Qt: https://bugreports.qt.io/browse/QTBUG-57186
Comment 28 sunwebrw 2017-04-15 06:21:19 UTC
It appears Qt guys won't fix it for Qt Quick Controls 1 since QQC2 is out without this bug. So the only solution is to port all of the QQC1 code to QQC2 just like you did for Kirigami. Or have wayland fully working which is not an easy route as well.

P.S. At this point i truly understand why RedHat doesn't go with Qt. It could be the best toolkit but if they aren't fixing bugs for your products it quickly becomes a pain.
Comment 29 Elvis Angelaccio 2017-07-06 21:55:28 UTC
Closing as duplicate of bug #375069 which has a better analysis of the issue. (https://bugreports.qt.io/browse/QTBUG-59261).

*** This bug has been marked as a duplicate of bug 375069 ***