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From: klee@wsl.dec.com (Ken Lee)
Newsgroups: comp.windows.x
Subject: Re: XGetImage, BadMatch
Message-ID: <1991Apr17.112248@wsl.dec.com>
Date: 17 Apr 91 18:22:48 GMT
References: <1991Apr17.022705.14758@odin.corp.sgi.com>
Sender: news@pa.dec.com (News)
Reply-To: klee@wsl.dec.com
Organization: DEC Western Software Laboratory
Lines: 16

In article <1991Apr17.022705.14758@odin.corp.sgi.com>, hajadi@goofy.csd.sgi.com (Ivan Hajadi) writes:
|> I copied the reflect_window program from Vol 1 O`Reilly book, and
|> tried to run it.  I keep getting BadMatch error.  Anyone knows
|> what's wrong with this program ?

This code commits the most basic error of X programming.  It creates
and maps a window then tries to use it (XGetImage) without waiting for
an expose or map event.  Since mapping is done by the window manager,
it is sometimes delayed.  The Xlib manual says you will get a BadMatch
if you do an XGetImage on an unmapped window, which is probably your problem.

-- 
Ken Lee
DEC Western Software Laboratory, Palo Alto, Calif.
Internet: klee@wsl.dec.com
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