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From: boerned@mist.CS.ORST.EDU (Dan Boerner)
Newsgroups: comp.sys.mac.programmer
Subject: Re: GetCIcon on a Mac +
Keywords: GetCIcon, Plus, Color Quickdraw, error
Message-ID: <1991Jun12.223358.3835@lynx.CS.ORST.EDU>
Date: 12 Jun 91 22:33:58 GMT
References: <1991Jun12.175142.12317@crash.cts.com>
Sender: @lynx.CS.ORST.EDU
Organization: Computer Science Department, Oregon State Univ.
Lines: 37
Nntp-Posting-Host: mist.cs.orst.edu

erich@crash.cts.com (Eric Hicks) writes:
"Does anyone know exactly what happens if one tries to call a color QuickDraw"
"function (e.g. GetCIcon) from a non CQD machine? (e.g. a Mac Plus)"

Last time I tried this it resulted in the big LaBomba.  The GetCIcon is an
Unimplemented Trap on non Color QD machines like the Mac Plus. 
I'm fairly sure that although some color QD features have been added to 
System 7.0 (like fake GWorlds), this trap is still unavailable on non Color QD
machines. 

To avoid the problem you should check for the availability of Color QD before
you make the GetCIcon call.  You can do this with Gestalt (described in IM-VI)
or SysEnvirons (described in IM-V) if Gestalt is unavailable.  The trick is to
check first, then call GetIcon instead.  Try something like this:

gHasColorQD is set during initialization...

	if gHasColorQD then
		aCIconHandle := GetCicn(iconRsrcID)
	else
		anIconHandle := GetIcon(iconRsrcID);

then later when you're ready to draw...

	if gHasColorQD then
		PlotCIcon(theRect,aCIconHandle)
	else
		PlotIcon(theRect,anIconHandle);

then when you're done..

	if gHasColorQD then
		DisposeCIcon(aCIconHandle);


--Dan Boerner
  Oregon State University