Path: utzoo!attcan!uunet!seismo!sundc!pitstop!sun!decwrl!labrea!rutgers!mit-eddie!uw-beaver!apollo!ulowell!hawk!jkeegan
From: jkeegan@hawk.ulowell.edu (Jeffrey Keegan)
Newsgroups: comp.sys.mac.programmer
Subject: Windows--HELP
Keywords: scrolling
Message-ID: <9569@swan.ulowell.edu>
Date: 11 Oct 88 05:46:00 GMT
Sender: news@swan.ulowell.edu
Reply-To: jkeegan@hawk.ulowell.edu (Jeffrey Keegan)
Organization: University of Lowell, CS Dept
Lines: 29

I am currently working on a terminal program. For various reasons (one of
which being speed), I am not using Text Edit but instead I've created my
own output routines. I've noticed a few problems that I have run into, but 
recently when I tested these problems on other programs (namely Microphone 
(version 1), Red Ryder (10.0), MiniTerm, and FModem) they are still there.
	
The first problem was when a window was in the background, scrolling
didn't work properly. Since then I have pretty much been able to get
around the problem, so I won't bother with this one. The real problem that 
I'm having is this:
	
If the window is dragged so that part of it is off the screen (and almost
every application I've seen that allows dragging windows allows parts of
them to be dragged off the screen), then scrolling can cause problems.
Specific example: you move the text window so the bottom half is off the
screen. Then you type enough text that the screen starts to scroll (I
handle scrolling with scrollrect, and draw all drawings to both an on
screen and off screen bitmap for update events), and it screws up. The
text that is still visible on the screen scrolls up fine, but none of the
text that was below the screen boundary scrolls up. In addition, usually
garbage is scrolled up instead (if I play around with the visrgn and
cliprgn fields of the grafport).. Also, playing around with those usually
upsets the lower rounded corners of the screen.
	
I need help.. Please reply if you have any idea how text scrolling should
be handled in a window that is not entirely visible.
	
	
..Jeff Keegan    jkeegan@hawk.ulowell.edu