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From: chandran@SLCS.SLB.COM (Sharat Chandran)
Newsgroups: comp.windows.x
Subject: Help on Invisible windows
Message-ID: <9003210343.AA15162.chandran@SLCS.SLB.COM>
Date: 21 Mar 90 03:43:16 GMT
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
Lines: 26


Here is a simple, hopefully crisp question, at the Xlib level:

     How do I create the "invisible (shadow/outline) windows" that 
"twm" uses when a user moves his window (so that the user knows where
the destination is going to be)?

I tried the obvious by setting the "background_pixmap" attribute of
the window to none.  It almost works. 

The window is "transparent" and looks normal when it is first placed.
But when I move this window, it has the contents of whatever was
underneath it the first time it was placed.  What are the window
attributes I need to set?

[I turned of backing store and save under for both the window and the
server just to make sure.]

Another related  question:  Once I create such a transparent window,
subsequent graphics calls to a window underneath it (via XPutImage)
does not show up.  I suspect that they are getting clipped.  Shouldn't
they show through?

Many thanks.

	chandran@asc.slb.com