@davidrevoy I think I might have some interesting context for this:
Wacom "Penabled" does not have a second button but you can still get pens that have a second button for it. In those cases the second button switches the pen into a mode where the tablet thinks it's an eraser.
The Wacom Linux drivers have a workaround for that that detects when the pen suddenly turns into an eraser and interprets this as "upper button pressed".
Might be related in some way?
@jakob Hi, yes, it is probably related. I met this type of button on the Lenovo Yoga 370 (my full review and workaround: https://www.davidrevoy.com/article976/lenovo-yoga-370-on-gnu-linux-technical-companion-article ) It's still possible to inject something via xsetwacom. The syntax is a bit weird:
xsetwacom --set "$YogaEraser" Button 1 "key +ctrl button 1 key -ctrl" # color picker
(for a Ctrl color picker modifier) and an eraser icon still appears on Krita, but it pick colors. On the XpPen, this workaround even doesn't work.
@davidrevoy Yeah sadly the configuration options of most other tablet drivers on Linux are "meh" compared to the Wacom driver (and even that isn't perfect).
I would really like seeing the Wacom driver to be changed into something more generic so that xsetwacom (and GUI tools for it) work for all the other brands as well...
@jakob Same, a universal "tablet GUI" cross distro and cross D.E. would be great...