void displayChanged(GLAutoDrawable drawable, boolean modeChanged, boolean deviceChanged) is no longer to be found in the GLEventListener.
What happen to it, do one not need it anymore? What if I want to test for extension and functionability changes on a Device Change?
Although the method was part of the interface, it was never actually used in the implementations so display changes didn’t provide notifications anyway. In Jogl2 it’s my guess they just cleaned up an unused artifact in the code. Also, now with the new native windowing system, when you create a window you specify which device it belongs to.
What happens when one move a window containing a GLCanvas to another screen? Is there something be called, or will it just work?
http://download.java.net/media/jogl/jogl-2.x-docs/javax/media/opengl/GLAutoDrawable.html
2nd paragraph: “Another implementation detail is the drawable reconfiguration …”
Explains it pretty well … at least I thought it does 
A GLEventListener impl. shall be able to handle multiple lifecycles, ie dispose/init …
However … a screenchange action doesn’t seem to be necessary, at least my tests have shown this.