Bug 453612

Summary:	Wayland touchpad - tap-to-click impossible to enable unless.. (includes solution)
Product:	[Applications] systemsettings	Reporter:	kfjellda
Component:	kcm_touchpad	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED WORKSFORME
Severity:	major	CC:	kde, nate
Priority:	NOR
Version First Reported In:	5.23.5
Target Milestone:	---
Platform:	Other
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description kfjellda 2022-05-10 07:26:40 UTC

It was marked as major, as this might be a showstopper for many. They might change their mind about using KDE/Wayland if they have to left click the mouse and cannot enable tapping on the touchpad. This brings back poor memories of double clicking in Windows and painful wrists. Furthermore, what prevents the enabling of tap-to-click is such a tiny thing, that it would be a major issue not to change it.

SUMMARY
In system-settings -> input devices, clicking/enabling "Tap-to-click" there is a bug when clicking "apply". It simply refuses to apply the setting and the apply button is never grayed out. In fact, it is not possible to apply the setting.

(Elan touchpad)

This was tested on a default Slackware 15.0 installation (with minor user modifications). Sadly I can't guarantee that it is possible to reproduce only in the "system settings", because I also made major changes to libinput config files in /usr/share/X11/xorg.conf.d/(libinput,evdev) and added "libinput" to /etc/X11/xorg.conf.d/
However, I think those config files had no impact on the outcome.

STEPS TO REPRODUCE
1. dbus-launch startplasma-wayland
2. go to "system settings" -> "input devices" -> "touchpad"
3. select "Tap-to-click" and try to "apply"
4. "applying" is not possible

EXPECTED RESULT
The setting should be applied as expected, and it should be possible to use tap-to-click after.

OBSERVED RESULT
It is not possible to apply the setting.

SOLUTION
When selecting "Tap-to-click", another suboption "Tap-and-drag" is automatically selected. If you deselect this option it is possible to enable "Tap-to-click" and apply the setting as expected. Tap-to-click works after applying the setting.

Please remove the selection of "Tap-and-drag" as a default option when enabling "Tap-to-click". Surely a user who additionally want "Tap-and-drag" can select this option..

SOFTWARE/OS VERSIONS
Slackware 15.0 and applicable KDE/Plasma versions (5.23.5?)

ADDITIONAL INFORMATION
Thank you!
KDE is sweet!

Comment 1 David Redondo 2022-05-10 08:20:13 UTC

Cannot reproduce might be a libinput issue maybe?

Comment 2 kfjellda 2022-05-10 15:34:03 UTC

No. I just tested it on another Slackware 15.0 installation where I haven't changed libinput config files, and I could reproduce the issue.

To be noted, my touchpad driver is Elan.

Furthermore, from memory, every time I have tested KDE/Wayland in the past I have had the exact same issue, and not been able to enable tap-to-click in systemsettings (and at all). That includes KDE/Wayland in another distro, Mageia X(probably 6 and/or 7).

Comment 3 Nate Graham 2022-05-10 16:06:51 UTC


*** This bug has been marked as a duplicate of bug 419136 ***

Comment 4 kfjellda 2022-06-13 09:46:58 UTC

This bug isn't a duplicate of that one, and has nothing to do with window geometry. It wasn't due to libinput either. Why does "tap-to-drag" have to be automatically enabled when you select "tap-to-click" anyways? It's another function entirely,  isn't it? Perhaps it should be opt in in the first place? (especially if it can, in some/many cases, create the issue described)

I beg you to do some more testing. I know the solution to this issue in my case so it doesn't matter to me personally, but it was incredibly frustrating for quite a long time, every time I tested KDE on Wayland. I don't want anyone else to experience that same trouble. Please if you have the option and time to do more extensive testing.

I have no idea why it is not reproducible, I can reproduce 100%. I can't think that hardware issues should cause this. But I am using Acer machines, and I am using Acer WMI, and that could potentially have something to say? That's the only potential "difference" I can think of, if this has been tested in general, and with Elan, and in particular if it was tested on Slackware/Mageia.

Have a nice day!

(I condsider this fully closed from my side now, I've done what I can, so I'm not going to continue this unless someone have questions and answers would be really helpful in reproducing it)

Comment 5 Nate Graham 2022-06-13 13:06:51 UTC

Just because you can reproduce the issue, does not mean that everyone can. :) Some bugs are tricky like that. Are you still using Plasma 5.23? Or is this reproducing on 5.24 too?

Comment 6 Nate Graham 2023-11-30 22:34:17 UTC

Closing due to lack of communication from the bug reporter and inability to reproduce the issue.