Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!wuarchive!mit-eddie!bloom-beacon!LARRY.MCRCIM.MCGILL.EDU!mouse
From: mouse@LARRY.MCRCIM.MCGILL.EDU
Newsgroups: comp.windows.x
Subject: Re:  "To scroll, or to let Motif scroll?" - that is the question.
Message-ID: <9008140218.AA08530@Larry.McRCIM.McGill.EDU>
Date: 14 Aug 90 02:18:08 GMT
Sender: daemon@athena.mit.edu (Mr Background)
Organization: The Internet
Lines: 29

> [...] Motif has a scrolled window widget which manages to perform
> scrolling by moving a (usually) larger window (in the Xlib sense)
> around inside a smaller viewport window.  The larger window is a
> child of the viewport so it is clipped to the viewport window.

> I need to decide if I should use this widget to do scrolling or if I
> should use a fixed window without the viewport.

> However, I get the feeling that there may be some drawbacks to using
> the Motif scrolled window as opposed to handling the scrolling
> directly.  I've got both ways working and the scrolled window appears
> to be faster, but I still have optimizations to make to my code.

I am not familiar with the widget in question.  However, a couple of
potential problems come to mind anyway....

If the server maintains backing-store for the child window, you'll be
eating up a lot of possibly scarce server-side memory unnecessarily.

If there's lots of stuff to scroll, the child window may try to be
larger than 65535 pixels[%], which will break badly.

[%] I know the value is 16 bits.  I think it's unsigned (sizes
    generally are); if it's signed, the limit is instead 32767.

					der Mouse

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