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From: klee@wsl.dec.com (Ken Lee)
Newsgroups: comp.windows.x
Subject: Re: X Protocol Error?
Keywords: BackgroundPixmap, XChangeWindowAttributes
Message-ID: <1990Dec14.150042@wsl.dec.com>
Date: 14 Dec 90 23:00:42 GMT
References: <1050@sppy00.UUCP>
Sender: news@pa.dec.com (News)
Reply-To: klee@wsl.dec.com
Organization: DEC Western Software Laboratory
Lines: 22

In article <1050@sppy00.UUCP>, jxf@sppy00.UUCP (Jonathan Fausey) writes:
|>   pix = XCreateBitmapFromData(wndw_disp, wndw_hndl,
|>                               RawBitmapData, NumBitsPerBitmapLine,
|>                               NumLinesInBitmap);
|>   WinAttr.background_pixmap = pix;
|>   win = XCreateWindow(wndw_disp, DefaultRootWindow(wndw_disp),
|>                            ulx, uly, width, height, 4, 1, InputOutput,
|>                            DefaultVisual(wndw_disp,wndw_screen), WinAttrMask,
|>                            &WinAttr);

This is poor programming style.  XCreateBitmapFromData creates a
bitmap, which always has a depth of 1.  You're then using this bitmap
as a window background pixmap without checking the depth in your
visual.  If the window has a depth other than 1, you will get a
protocol error.  You must make sure that window background pixmaps have
the same depths as the windows.

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