Understanding gtk_widget_queue_draw() (and dbl buffing)

[Derek Simkowiak <dereks kd-dev com>]

	gtk_widget_queue_draw() does not double buffer, does it?  

	I took a quick glance at the code (1.2.6) and it seems to me that
widget_queue_draw() just merges together rectangle areas and then
schedules expose events on those rectangles when idle.

	So, assuming my understanding is correct, the only advantage of
using widget_queue_draw() is that it's less network intensive, because
there are fewer expose events actually sent to the X server.  Also, there
is an advantage that drawing is done when idle, so that the calculations
of your application/custom widget can continue without waiting for slow X
requests.

	(In case it's not obvious, I'm a novice to X programming)

	I'm working on a new widget (the View for my text widget), and I'm
wondering if I need to do double buffering myself.  I've seen some
messages indicated that Gtk 1.4 would have built-in double buffering,
whatever that means.

	Should I write my widget to do its own double buffering?  If so, I
plan on having my expose signal handler draw first to a pixmap, and then
copy to the GdkWindow widget->window.  Is that the right approach?


--Derek