[racket-dev] mouse motion events in Linux

Dear list,

Recently I noticed that on Linux, the canvas only
receives mouse motion events if some mouse button is
pressed.

Since this is not mentioned in the documentation I assume
this behaviour was not intended, please correct me if wrong.

The cause of this behaviour is the use of the flag
  GDK_BUTTON_MOTION_MASK in
collects/mred/private/wx/gtk/canvas.rkt

This flag indeed means "only send motion events if a button is down".
If all motion request are desired the flag
  GDK_POINTER_MOTION_MASK
should be used instead.

I have sent a pull request for this one-line change on github and would
recommend that it gets merged, if indeed receiving all motion
events is the intended behaviour.

Thanks,

Stephan