Bug 395404

Summary: "Press left and right buttons for middle click" setting is not remembered under Wayland
Product: [Applications] systemsettings Reporter: Patrick Silva <bugseforuns>
Component: kcm_touchpadAssignee: Plasma Bugs List <plasma-bugs>
Status: RESOLVED FIXED    
Severity: normal CC: herzenschein, meven29, nate, subdiff
Priority: NOR    
Version: 5.17.5   
Target Milestone: ---   
Platform: Arch Linux   
OS: Linux   
Latest Commit: Version Fixed In:
Sentry Crash Report:

Description Patrick Silva 2018-06-15 00:23:43 UTC
on neon dev unstable

start wayland session
open system settings > input devices > touchpad
check "Press left and right buttons for middle click"
click "apply" button and close the window
reopen system settings > input devices > touchpad
"Press left and right buttons for middle click" is unchecked again
Comment 1 Patrick Silva 2018-09-17 03:30:38 UTC
Still reproducible on neon dev unstable.
Comment 2 Thiago Sueto 2019-01-24 16:29:35 UTC
Can reproduce under mouse settings as well, so this is not exclusive to the touchpad KCM.

I'm on KDE Neon Git Stable (the 5.14.90 beta), also under Wayland session.
Additionally, ticking its box does not make the "Apply" button clickable, unlike all other options with tickboxes.
Comment 3 Patrick Silva 2019-02-14 18:37:42 UTC
(In reply to Thiago Sueto from comment #2)
> Can reproduce under mouse settings as well, so this is not exclusive to the
> touchpad KCM.
I can confirm.

Operating System: Arch Linux 
KDE Plasma Version: 5.15.0
KDE Frameworks Version: 5.55.0
Qt Version: 5.12.1
Comment 4 Patrick Silva 2019-03-02 13:11:22 UTC
Bug persists.

Operating System: Arch Linux 
KDE Plasma Version: 5.15.2
KDE Frameworks Version: 5.55.0
Qt Version: 5.12.1
Comment 5 Patrick Silva 2019-05-20 00:43:33 UTC
Plasma 5.16 beta has the same bug.

SOFTWARE/OS VERSIONS
Operating System: Arch Linux 
KDE Plasma Version: 5.15.90
KDE Frameworks Version: 5.58.0
Qt Version: 5.13.0 beta3
Comment 6 Patrick Silva 2019-06-16 13:48:37 UTC
The same bug affects Mouse kcm on X11.
Comment 7 Patrick Silva 2019-09-05 18:07:44 UTC
This bug persists.

Operating System: Arch Linux 
KDE Plasma Version: 5.16.5
KDE Frameworks Version: 5.61.0
Qt Version: 5.13.1
Comment 8 Méven Car 2020-03-26 09:31:41 UTC
I don't reproduce this bug with Plasma 5.19 from sources.

Operating System: Kubuntu 
KDE Plasma Version: 5.18.80
KDE Frameworks Version: 5.68.0
Qt Version: 5.12.4

Patrick do you still reproduce with Plasma 5.18 or newer ?
Comment 9 Patrick Silva 2020-03-26 11:04:37 UTC
On Arch Linux running Plasma 5.18.3 with a mouse I not even can check
"Press left and right buttons for middle click" because "Apply" button
is not enabled.
On Neon unstable this bug is still reproducible with touchpad
and mouse.

Operating System: KDE neon Unstable Edition
KDE Plasma Version: 5.18.80
KDE Frameworks Version: 5.69.0
Qt Version: 5.14.1
Comment 10 Méven Car 2020-03-27 10:05:19 UTC
Could it be your hardware or libinput does not support this on your platform ?
This would explain the issue of the setting not being saved.

Could you find out if that is the case :
$ qdbus --print-reply org.kde.KWin /org/kde/KWin/InputDevice/event4 org.freedesktop.DBus.Properties.Get org.kde.KWin.InputDevice supportsMiddleEmulation

You may need to adapt the query in particular the event4 to correspond to your touchpad
You can use query such as :
qdbus --print-reply org.kde.KWin /org/kde/KWin/InputDevice/event4 org.freedesktop.DBus.Properties.Get org.kde.KWin.InputDevice name

Or you can use qbusviewer for instance

If so I just merged a fix, that will make the UI reflect the fact the feature is not supported by a device. https://phabricator.kde.org/D28297
This will be part of Plasma 18.04.
Comment 11 Patrick Silva 2020-03-27 10:33:30 UTC
output of

$ qdbus --print-reply org.kde.KWin /org/kde/KWin/InputDevice/event7 org.freedesktop.DBus.Properties.Get org.kde.KWin.InputDevice supportsMiddleEmulation

is "false".

(In reply to Méven Car from comment #10)
> If so I just merged a fix, that will make the UI reflect the fact the
> feature is not supported by a device. https://phabricator.kde.org/D28297
> This will be part of Plasma 18.04.
did you mean it will be part of Plasma 5.18.4?
"Press left and right buttons for middle click" is already greyed out on Neon unstable.
Comment 12 Méven Car 2020-03-27 10:43:14 UTC
Yes I meant Plasma 5.18.4.

Well neon might have already the patch. (when something hits the next stable branch we land the changes to master as well)

So I guess this bug can be considered fixed.
Comment 13 Patrick Silva 2020-03-27 11:32:09 UTC
State of "Press left and right buttons for middle click" setting of Mouse KCM
is saved and such feature works as expected on both X11 and Wayland sessions
of Neon unstable. Therefore, this bug is really fixed.
Thank you very much Méven.

Maybe you can take a look on these other Touchpad KCM bugs:
bug 408116
bug 408338