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From: mouse@lightning.mcrcim.mcgill.EDU (der Mouse)
Newsgroups: comp.windows.x
Subject: Re:  How do I get ID of the window that contains the pointer ?
Message-ID: <9104130151.AA08621@lightning.McRCIM.McGill.EDU>
Date: 13 Apr 91 01:51:31 GMT
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
Lines: 30

> How do I get ID of the window that holds the pointer ?

Which window that holds the pointer?  There's a whole chain of windows,
all the way from the root down to the smallest application window, all
of which could be said to hold the pointer.

Two plausible things you might want are (1) the "top-level" window
containing the pointer (ie, the highest window that was created as a
child of the root) or (2) the lowest (ie, innermost) window containing
the pointer.

> In most cases this window would belong to other application.  Which
> rules out XQueryPointer()

I don't see why.  You need to keep doing XQueryPointer calls, tracing
your way down through the window tree until you find the window of
interest, and unless you grab the server and the pointer there are race
conditions, but with those caveats it should work fine.

> Also, I want to get this window ID without any user input.

The user need not do anything in the above scenario; in fact, the
reason I said you need to grab the pointer is to freeze it, so that
user input doesn't cause the mouse to change windows while you're
chasing down the window tree.

					der Mouse

			old: mcgill-vision!mouse
			new: mouse@larry.mcrcim.mcgill.edu