Paste Button for Logitech Trackball under Wayland

Help
,
1

I’m using Plasma 6.2.0, Framework 6.6.0 (Opensuse Tumbleweed).
My Logitech Trackball Marble FX works fine under X-Server. The big buttons (A,D) act as regular left / right buttons. The small button left (B) acts as a scrolling button or as a paste button.
Under Wayland I managed to configure the small button left as a scrolling button by
dbus org.kde.KWin /org/kde/KWin/InputDevice/event4
org.kde.KWin.InputDevice.scrollOnButtonDown true
But paste works only by pressing buttons left and right simultaneously (like in ancient times with 2 button mice).
How can I configure small button left as a paste button?

My X11 .conf file contains:

#       - - - Logitech Marble Mouse Settings - - -
#
#       The Logitech Marble Mouse buttons are mapped [A-D] from left to right:
#       A (large); B (small) |  C (small); D (large).
#
#       Preferred options for right-handed usage:
#       A = normal click [1]
#       B = middle-click [2]
#       C = middle-click [2]
#       D = right-click [3]
#       Hold button B while rolling trackball to emulate wheel-scrolling.
#
#       Preferred options for left-handed usage:
#       A = right-click [3]
#       B = middle-click [2]
#       C = middle-click [2]
#       D = normal click [1]
#       Hold button C while rolling trackball to emulate wheel-scrolling.
#       Pressing both large buttons simultaneously (b) produces a "back" action.

Section "InputClass"
        Identifier  "Marble Mouse"
        MatchProduct "Logitech USB Trackball"
        MatchIsPointer "on"
        MatchDevicePath "/dev/input/event*"
        Driver "libinput"

#       Physical button #s:     A b D - - - - B C
#       Option "ButtonMapping" "1 8 3 4 5 6 7 2 2"   right-hand placement
#       Option "ButtonMapping" "3 8 1 4 5 6 7 2 2"   left-hand placement
#       b = A & D
        Option "ButtonMapping" "1 8 3 4 5 6 7 2 2"

#       EmulateWheel: Use Marble Mouse trackball as mouse wheel
#       Factory Default: 8; Use 9 for right side small button
        Option "ScrollMethod" "button"
        Option "ScrollButton" "8"

#       EmulateWheelInertia: How far (in pixels) the pointer must move to
#       generate button press/release events in wheel emulation mode.
#       Factory Default: 50
        Option "AccelerationScheme" "adaptive"

#       Axis Mapping: Enable vertical [ZAxis] and horizontal [XAxis] scrolling
        Option "ZAxisMapping" "4 5"
#       Option "XAxisMapping" "6 7"

#       Emulate3Buttons: Required to interpret simultaneous press of two large
#       buttons, A & D, as a seperate command, b.
#       Factory Default: true
        Option "MiddleEmulation" "true"
EndSection
2

I’m trying something similar, but can’t even get the scrolling to work.
libinput debug-events shows me I should use event8, but when I try to run qdbus6 org.kde.KWin /org/kde/KWin/InputDevice/event8 org.kde.KWin.InputDevice.scrollOnButtonDown true
I get

Cannot find 'org.kde.KWin.InputDevice.scrollOnButtonDown' in object /org/kde/KWin/InputDevice/event8 at org.kde.KWin

Any ideas what I’m missing?

3

Same, nor can I get my Elecom trackball to see the forward button or the other 3 custom buttons. After 20 years, it would be nice if Logitec would put a simple scroll wheel on the MM. There is plenty of room. I only use trackballs. Why anybody would use a mouse is beyond me.

4

I think what happens is libinput exposes middle button emulation (where you left and right click at the same time) and Plasma simply assigns middle button emulation to paste (that’s in General Behavior → Middle click: Pastes selected text). It’s not like you can have a direct assignment between a specific button and middle button emulation to get paste functionality I don’t think.

Have you seen the feature showcased in Allow rebinding of extra mouse buttons on Wayland (!920) · Merge requests · Plasma / Plasma Desktop · GitLab ? Does it work for your trackball mouse?

In case it doesn’t, with the new “We care about your input” KDE Goal, there’s some work going on about supporting more devices: Devices (#9) · Issues · Teams / KDE Goals / We care about your Input · GitLab

I have a Trackman Marble as well (not FX), and at least from my side I find it rather annoying that I need to use qdbus to set that button as scroll wheel.

5

Sorry for the late reply, I didn’t had access to my PC the last weeks.

It seems to me that the qdbus behavior changed to qdbus6. The old behavior was that I could enter an interactive mode with the 1st line, the 2. line was an input for that.

Nevertheless I found an GUI tool, which provides the same functionality.

Start qdbuswiever6
Select service org.kde.KWin on the left side.
Navigate to /org/kde/KWin/InputDevice/eventXX (event 8 in your case)
In that event navigate org.kde.KWin.InputDevice
Go to Property: scrollOnButtonDown
With the right mouse button select “Set Value” and change to “True”
Done

6

qdbusviewer6 shows for my Trackball org.kde.InputDevice the properties:
supportsMiddleEmulation, middleemulationEnabledByDefault and middleEmulation are all set to False without the ability to change.
Any idea how to change that?