send mouse events to the OpenGL window

No idea why the events are send to ScgridWindow but this hack works for
now. It is not perfect and surely not beautiful but does work.

Change-Id: If620e471083d34004ee877a25f8731d7b4212f3c
volatile does not make any sense here

Change-Id: I895f6d04bbd5bd1829ec72b2051e640cbc153b26