[pygtk] transparent layer using DrawingArea/cairo

[Jeremy Flores]

Hi,

I'm trying to make a transparent DrawingArea layer on top of another 
DrawingArea so that I can draw a selection rectangle. However, I'm 
noticing that the DrawingArea always has a default gray background that 
overlaps anything behind it. Is there any way to get rid of this, 
possibly using a cairo context (since it has an optional alpha channel)?

Thanks,
Jeremy Flores