Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!zaphod.mps.ohio-state.edu!caen!spool.mu.edu!uunet!vtserf!creatures!csgrad!davism
From: davism@csgrad.cs.vt.edu
Newsgroups: comp.sys.mac.programmer
Subject: Re: Problems with 'cicn's
Summary: Solved!!
Message-ID: <1327@creatures.cs.vt.edu>
Date: 27 Jun 91 19:15:50 GMT
Article-I.D.: creature.1327
References: <1326@creatures.cs.vt.edu>
Sender: usenet@creatures.cs.vt.edu
Reply-To: davism@vtopus.cs.vt.edu (Mat Davis)
Organization: Virginia Tech Computer Science, Blacksburg, VA
Lines: 25

In article <1326@creatures.cs.vt.edu> davism@vtopus.cs.vt.edu (me) writes:
>I'm trying to get "bouncing" buttons working using color icons. 
>...
>I discovered in THINK C that the icon mask doesn't appear to be valid
>until *after* the cicn is drawn the first time (with PlotCIcon), but
>I'm not trying to use it until after the first draw.

I tracked down the problem: apparently the mask is only valid just after
a call to PlotCIcon and is subject to some kind of trashing later.  I 
finally reorganized the code so that the mask is never used except just
*after* it's been drawn.  That isn't the most logical way to structure
it, but it appears to be the only way that works.

I'd suggest one or more of the following changes:

	1. Make the internal structures valid at all times
	2. Document the times that they *are* valid
	3. Don't document the internals.

Anyway, another bug bites the dust!!

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                               Mat Davis
			     Virginia Tech
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