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From: kit@EXPO.LCS.MIT.EDU (Chris D. Peterson)
Newsgroups: comp.windows.x
Subject: Re: using XtIsManaged or XtIsRealized
Message-ID: <8904142042.AA00296@expo.lcs.mit.edu>
Date: 14 Apr 89 20:42:55 GMT
References: <8904141416.AA21116@expo.lcs.mit.edu>
Sender: daemon@bloom-beacon.MIT.EDU
Organization: The Internet
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> Your original question:

> > The
> >images will change depending on what the user wants to look at, so I
> >need to be able to "wipe out" the image in a Core widget and then redo
> >it with the new image.

> Set the window background pixel to the white pixel of the screen,
> then clear the window:

> XSetWindowBackground(dpy, win, WhitePixel(dpy, screen_number));
> XClearWindow(dpy, win);


From Carol's message it is not clear what is necessary to redraw the window.
If you are drawing the image from an exposure handler then you will need
to make a call to XClearArea() with exposures set to TRUE.  If you are
using a background pixmap you can get by with making a call to XClearWindow()
after you have set the background pixmap.  This will cause the server to
refresh your window from the background pixmap.  In any case I don't believe
that it is necessary to call XSetWindowBackground().


                                                Chris D. Peterson
                                                MIT X Consortium