How do you create expanding box cursors ...

[Jim Parker <hopeye cfl rr com>]

.. using a gtkglarea widget ?

I am thinking in terms of rubber banding lines and selection boxes during
interactive drawing.

I have been able to do a crude example using a gtk_drawing_area, but now I
need to use a gtkglarea.

TIA

cheers,
Jim Parker

BTW sorry if this is off subject.