This allows widget to attach their streams to GdkWindow(s)
The idea is to allow attaching a stream to windowing system(s) so the
stream can make use of its resources, in particular GL contexts.
I am however unsure what to attach to:
- GtkWindow
- GdkWindow
- GtkWidget
- GskRenderer
Each of these provide advantages and disadvantages.
So I'm very much open to better suggestions.