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From: reiss@husc9.harvard.edu (Peter Reiss)
Newsgroups: comp.sys.mac.programmer
Subject: Question: scrolling in a window
Message-ID: <1991Mar15.032155.305@husc3.harvard.edu>
Date: 15 Mar 91 08:21:54 GMT
References: <1991Mar14.021122.292@husc3.harvard.edu>
Organization: Harvard University Science Center
Lines: 5
Nntp-Posting-Host: husc9.harvard.edu

I have implemented scroll bars in a program and they work, except that whenever
the user clicks in the arrow region, I am redrawing the entire picture.  This
works, but does not look very good.  I have noticed that most programs seem to 
scroll graphics by shifting the current picture in one direction and drawing
in the extra area.  How can I do this?