Need help with drawing layers design

["John McDermott" <jjm jkintl com>]

I am developing an app for annotation of a display. I want it to work like  
this:
On a window will be displayed some application (e.g. a browser)
The same window is overlayed with a transparent drawing layer.
  The user will be able to draw on the drawing layer to "annotate"
  the underlying application.
I would like to send the whole image (both layers) to a second display
  using Gtk2::Gdk::Display, presumably

I know how to do the drawing in step 2.  I think I can use one pixmap on  
two displays to handle the copying of the annotations.  I do not know how  
to put a live application behind it and to display both layers on the  
second display. Does anyone have any pointers?

Thanks,
--john
--
John McDermott, CPLP, CCP
Writer, Educator, Consultant
jjm at jkintl.com        www.jkintl.com
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