When a window has moved over a component, how to listen for this

#1

In my OpenGL hacks I've found I need to repaint when a window occludes the opengl rendering area, but since there are no messages going to the component, how does it know to repaint? 

Is there something like virtual onOverlappingWindowMovement() anywhere?

#2

I'd be very sceptical about a hack that made that necessary!

Nope, there's certainly no way to detect window overlapping, but that's the wrong way to look at it anyway - if a window region needs repainting, then win32 sends you a repaint message. Obviously the juce classes normally handle that for you, but if you've hacked things so that it no longer works, then good luck!

#3

Ah ok. I'll have to debug where that repaint message is going. 

#4

You've probably got the Juce OpenGL 'on-demand' rendering turned on (gag).

Make sure that your repaint override triggers a fresh OpenGL paint. I wouldn't be surprised if the on-demand thing had some edge cases. It feels hacky to me - every other OpenGL system renders every frame, even when nothing has changed.

Bruce