Sets the event mask for any floating device (i.e. not attached to any
visible pointer) that has the source defined as source. This event
mask will be applied both to currently existing, newly added devices
after this call, and devices being attached/detached.
Sets the event mask for any floating device (i.e. not attached to any visible pointer) that has the source defined as source. This event mask will be applied both to currently existing, newly added devices after this call, and devices being attached/detached.