plasma + wayland elecom huge trackball settings

PLASMA_WAYLAND_TRACKBALL.md

This is how I was able to hack around settings for my elecom huge trackball on plasma+wayland (for comparison: similar xorg setup: https://gist.github.com/WaffleLapkin/8b0b739b705e91a0dd9babccd0907267).

/etc/udev/hwdb.d/70-elecom-huge-trackball-remap.hwdb:

# Rebinds keys on elecom huge trackball
#
# tip: You can use `sudo evtest` to get the key values and stuff.
#
# 90001 = L
# 90002 = R
# 90003 = M (scroll wheel button)
# 90004 = < (back)
# 90005 = > (forward)
# 90006 = Fn1
# 90007 = Fn2
# 90008 = Fn3
#
# key_blue -- noop
# btn_0 -- corresponds to key code 256. idk what it does,
#          but we can make kwin see it as "scroll" button
#          (sadly kwin only wants btn_*, key_* won't work...)
evdev:input:b0003v056Ep010D*
  KEYBOARD_KEY_90001=key_blue
  KEYBOARD_KEY_90002=btn_0
  KEYBOARD_KEY_90003=key_blue
  KEYBOARD_KEY_90004=btn_middle
  KEYBOARD_KEY_90005=key_blue
  KEYBOARD_KEY_90006=btn_left
  KEYBOARD_KEY_90007=btn_right
  KEYBOARD_KEY_90008=key_esc

Then run sudo systemd-hwdb update && sudo udevadm trigger. Then do kwin setup:

set event (basename (readlink /dev/input/by-id/usb-ELECOM_TrackBall_Mouse_HUGE_TrackBall-event-mouse))
qdbus org.kde.KWin /org/kde/KWin/InputDevice/$event org.kde.KWin.InputDevice.scrollOnButtonDown true
qdbus org.kde.KWin /org/kde/KWin/InputDevice/$event org.kde.KWin.InputDevice.scrollButton 256

Sources:

1. https://forums.fedoraforum.org/showthread.php?328508-Wayland-mouse-button-remapping
2. https://forums.opensuse.org/t/swapping-mouse-button-in-wayland-kde/172776/4
3. https://wiki.archlinux.org/title/Logitech_Marble_Mouse#Plasma_and_Wayland