[gtkmm] transparent background in drawing area

[Sven Eric Panitz <panitz tfh-berlin de>]

Hi all,
I started to play around  a bit with gtkmm just recently. I wonder how to 
create a (undecorated) window containing a drawing
area, such that background of the window (and drawingarea) are
transparent. I had a look at the wheelbarrow example, which seems rather 
complicated, since it needs to define a mask for a picmap.

Any ideas? (For an exercise I was trying to write a clock with
transparent background for my desktop).

thanks in advance sven eric

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