fixed position, fixed size

[Joe Van Dyk <joevandyk gmail com>]

I have a gnomecanvas object (is this the right list?).  The user can
move around in the object by pressing arrows that are drawn in the
lower right hand corner of the object.

I'm guessing when the user clicks a move arrow, I'd use
gnome_canvas_scroll_to(cx, cy) to scroll on the canvas.

The user can also zoom in and out on the canvas.

So each time the user moves or zooms, I'd need to rerdraw those
movement arrows so they stay in the same place and say the same size
(in pixels on the user's screen).

Is there an easy way to do this?  Or do I need to delete the old
arrows, figure out where in the world coordinates to draw the new
arrows, and query the current zooming level to figure out how large
the arrows should be?

Thanks,
Joe