how to make sure this thing is drawn

[lacage email enst fr (Mathieu Lacage)]

hi,

i am currently trying to do something strange. 
It is some widget build for bonobo
Basically, what i have is a widget which inherits GtkBin
This widget has a widget inside itself and a "cover"
The cover is a GdkWindow which happens to have exactly the same
size as the contained widget and which is positioned upon the 
contained widget.
Thsi allows you to change the way events are sent to the widget 
without changing the way it is displayed because we paint nothing
on the cover.

I am trying to paint things on the cover.
I use gdk_draw_rectangle but nothing is displayed.
The contained widget gets nothing drawn upon it. It looks
as if nothing had happened.
(i have modified the expose and draw method of the widget)

Any idea ?

regards,
Mathieu