Marky Multiouch

Thanks for this work-around, I'll try that (and hope for a more ergonomic possibility in the future!). Regarding the IDs: Indeed, they also change on my machine after each start-up and depending on when I connect the projector to the machine. The only stability I have is that I get three consecutive IDs for the projector's input devices, and within those three values, they are ordered consistently each time. However, I start Xournal only after that, so during the program's execution the IDs and GdkDevice-pointers...

XInputDevice-dependent tool/color/... selection