The Gtk+ 3 migration guide shows how the GdkEventExpose.region field can be used to provide a fine-grained area for re-rendering widgets. We already do something like this in Inkscape to avoid rendering excessive amounts of complicated stuff on our drawing canvas.
However, the example in the guide shows how to do this for the old Gtk+ 2 expose_event handler.
How do I do the equivalent in a new Gtk+ 3 draw handler, which receives a "ready-clipped" Cairo context as a parameter, rather than a GdkEventExpose?
I guess one possibility is to use cairo_copy_clip_rectangle_list on the "ready-clipped" cairo context to obtain a list of rectangles that make up the region to draw. Does anyone have any experience of using this? Does it seem like a sensible approach?
