[comp.windows.x] Overlaying a program on a window

mlandau@bbn.com (Matt Landau) (02/19/88)

   Is there any *generic* way within X11 to convince a program that it
should run by overlaying an existing window, instead of creating a new
window?

   In SunView, there is something called a "blanket window" that can be
created on top of a normal window.  Many SunView programs work by opening
a blanket window on top of whatever window is named by the $WINDOW_GFX
environment variable.  This allows one program to create a window, then
run another process within it by setting WINDOW_GFX to the name of that
window before forking a child.

   Is there some way to get the equivalent effect in X?  I've looked at
both the Xlib and protocol documents, but don't really see what I'm after.
Ideally, it would be possible to set some kind of hint for a client to
indicate that a window creation request should really return the id of an
existing window, rather than create a new one.  This would allow completely 
naive clients to be run inside windows created by other applications on 
their behalf.