Path: utzoo!utgpu!jarvis.csri.toronto.edu!mailrus!cwjcc!gatech!prism!vsserv!loligo!pepke
From: pepke@loligo (Eric Pepke)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Spleen venting (was: Re: 32-bit OS)
Message-ID: <118@vsserv.scri.fsu.edu>
Date: 25 Aug 89 16:10:57 GMT
References: <22321@andante.UUCP> <1989Aug19.221033.2241@geology.wisc.edu> <8352@hoptoad.uucp> <34184@apple.Apple.COM> <2601@iscuva.ISCS.COM> <8380@hoptoad.uucp> <1397@intercon.UUCP>
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Reply-To: pepke@loligo.UUCP (Eric Pepke)
Organization: Supercomputer Computations Research Institute
Lines: 33

In article <1397@intercon.UUCP> amanda@intercon.uu.net (Amanda Walker) writes:
>However, in the specific case of scroll bars for big views (like 60 page
>TIFF files), I'm not sure what the problem is.  The value range of the control
>is only relevant when you are moving or positioning the thumb directly.
>a 16 bit value *doesn't lose you anything*!  Now personally, I agree that
>using shorts for everything is really annoying (esp. in the List Manager
>and TextEdit), but in this particular case it's not a very hard limit.
> [and describes one good clean way of doing high-precision scrolling.]

I agree.  Only a very naive programmer would have any difficulty making
16-bit scroll bars do what was required.  I've used the SetOrigin by the
scrollbars technique a few times, but only when the job I had to do was
very simple.  When you want to work with very large structures, you will
want to do better and faster clipping than QuickDraw does automatically,
anyway, so is a half dozen extra lines of code to convert really that
big a deal?

You will run into any arbitrary limitation sooner or later, and what the
arbitrary limitation is is of secondary importance.  I implemented scrolling 
for a dataset of objects with real coordinates and arbitrary zoom.  The fact
that scroll bars don't return real numbers didn't cause me to lose any sleep.

As for TextEdit, I wish that it could do more than 32K characters and do
so lickety-split, but then again, I am more interested in seeing it do
tabs and super- and subscripts.

Eric Pepke                                     INTERNET: pepke@gw.scri.fsu.edu
Supercomputer Computations Research Institute  MFENET:   pepke@fsu
Florida State University                       SPAN:     scri::pepke
Tallahassee, FL 32306-4052                     BITNET:   pepke@fsu

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