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From: RWS@ZERMATT.LCS.MIT.EDU (Robert Scheifler)
Newsgroups: comp.windows.x
Subject: bit_gravity vs. popup menus
Message-ID: <19881027151502.1.RWS@KILLINGTON.LCS.MIT.EDU>
Date: 27 Oct 88 15:15:00 GMT
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    Date: 19 Oct 88 00:02:08 GMT
    From: sgi!daisy!klee@bloom-beacon.mit.edu  (Ken Lee)

    We have a client that uses SouthWestGravity on resize.
    ...
    Note that when the client reads the expose event, the server has
    already moved the graphics, but the client doesn't know it yet, so the
    client redraws in the (old) wrong place, leaving a hole in the (new)
    right place.  Does anyone know of a good, clean way to redraw
    correctly?

One way is to enable ResizeRedirect on your window, in which case
the window manager's resize request will not be executed, but will
be sent to you as an event.  You are obligated to obey that request,
but you are now in a position to do it synchronously, so you will
know when the gravity shift takes effect.

    We'd prefer not to have to use backing store, since that's
    pretty expensive on our color displays.

Using save-under on the popup menu would also help.