3-Finger Gestures on Touchscreen Bug

Hi all,

I’ve found a bug that I can easily replicate on every bootup of my machine that flummoxes me: When using 3-finger swipes to switch desktops or open overview on my touchscreen, edit mode is entered (initially) and subsequent attempts to use 3-fingered gestures cause a selection rectangle to be opened on my desktop (wherever the mouse is positioned).
Note that this is NOT an issue with touchpad gestures (flawless), just my touchscreen.

A lot of words here to describe a weird problem: To reproduce on my laptop:

  • #1: Use 3f gestures on touchscreen → enter edit mode
  • #2a: Exit edit mode, try to use gestures again → edit mode is not entered, but a selection rectangle is permanently shown on the desktop which follows the mouse (even without pressing either mouse button).
  • #2b: (Notably, once this selection rectangle is present, 3f gestures on the touchscreen are flawless.)
  • #3: Only way to remove this selection rectangle is to either log out or to use the selection rectangle to “actually” select something on the desktop. This does remove it, however…
  • #4: Once the selection rectangle is removed, using 3f gestures on the touchscreen begins step #1 all over again.

My hardware/software specs:

  • Wayland session

  • Plasma: 6.0.4

  • KDE framework: 6.2.0

  • Qt version: 6.7.0

  • OS: Arch linux, 6.9.1 kernel

  • T480s Thinkpad

  • CPU: intel i5-8th gen

  • GPU: intel Mesa UHD 620

  • Ram: 16Gb

Any ideas/input would be much appreciated! Not sure if this is a plasma issue or a thinkpad screen issue.

Smathles

1 Like

I’ve got the same problem!

Thanks for pointing out that it disappears when selecting an item on the desktop.
I had nothing on my desktop, but once I put something I can confirm it works.

I removed it using other multi-finger gestures (4 and 5 fingers).
But, I cannot do it successfully every time.
I’m not sure what triggers it to exit out of the “selection” state.

kwin_wayland --replace & also does the trick, but it’s by no means a solution.

System Info:

Lenovo Yoga 7
OS: Manjaro Linux x86_64 
Kernel: 6.1.90-1-MANJARO 
KDE Plasma Version: 6.0.4
KDE Frameworks Version: 6.1.0
Qt Version: 6.7.0
Graphics Platform: Wayland
Graphics Processor: AMD Radeon Graphics
Processors: 12 × AMD Ryzen 5 5600U with Radeon Graphics
Memory: 16 GiB of RAM

Good to hear it’s not just me hallucinating :skull:! Generally, I don’t keep icons on the desktop (krunner was made for a reason lol) and like that aesthetic, but as long as this is a bug, might keep a photo there to get rid of this issue.

Possible note for devs/others troubleshooting is we both use lenovo touchscreens? It would be nice if someone else can replicate this on a non-lenovo laptop setup!

Update: This is bug 482222. According to Nate, it seems to possibly be because “the gestures aren’t being exclusively captured by KWin”.

So it’s a confirmed Kwin bug, not just a weird hardware issue on my end it seems.

1 Like

Bug Detail Update:

I haven’t tried fixing or debugging this issue (kwin stuff is beyond me), but I noticed an interesting detail: 3-finger gestures to move to different virtual desktops are perfectly functional as long as the gesture is performed on top of an application, not the plasma desktop background/wallpaper area!

To replicate this, have at least 2 adjacent virtual desktops with maximised application windows open. 3-finger gestures now work perfectly!

Notably, this even works with non-maximised windows as long as the gesture is not started on the desktop!


For example, in the above image:

  • If I start a 3-finger gesture on the terminal window, virtual desktop switching/overview/grid display is flawless.
  • If I start a 3-finger gesture on the task manager/lower bar (tricky, but doable), virtual desktop switching/overview/grid display is flawless.
  • If I start a 3-finger gesture anywhere on the desktop background/wallpaper area, the issue immediately appears with symptoms as per bug 482222!

So this additional info is perhaps not “riveting stuff”, but IMO all debug information is helpful for those fixing bugs! I’ll update the bug report now as well.