Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!uunet!brunix!omh
From: omh@cs.brown.edu (Owen M. Hartnett)
Newsgroups: comp.sys.mac.programmer
Subject: Re: when to use NewCWindow?
Message-ID: <68833@brunix.UUCP>
Date: 17 Mar 91 05:56:39 GMT
References: <12364@pt.cs.cmu.edu>
Sender: news@brunix.UUCP
Reply-To: omh@cs.brown.edu (Owen M. Hartnett)
Organization: Brown University Department of Computer Science
Lines: 30

In article <12364@pt.cs.cmu.edu> hairston@henry.ECE.CMU.EDU (David Hairston) writes:
>
>how do you determine when it is absolutely safe to use NewCWindow
>as opposed to NewWindow?  i'm confused by the all things you can
>test and their implications (i.e. sys environs and gdFlags, etc.).
>i'd like to use NewCWindow unless the hardware absolutely prohibits
>this, in which case my newWindow() function would use NewWindow
>instead.

The new Gestalt function would let you test for color QD.

However, this should be one of those things that *you shouldn't have to
test* - but you probably do.  Why? a CWindow is just like a Window except
that it has more fields.  NewCWindow on a non color QD machine should
just return a CWindow with the extra fields.  It can't do anything with
them, but at least it won't crash because of a NewCWindow call and it
means that the programmer won't have to put in conditional code if the
user has colorQD or not just to support having color in his window.

I'm not saying that NewCWindow works like this, or that it doesn't work
like this (I haven't tried it on a non color machine) but this is how it
should work.

-Owen


Owen Hartnett				omh@cs.brown.edu.CSNET
Brown University Computer Science	omh@cs.brown.edu
					uunet!brunix!omh
"Don't wait up for me tonight because I won't be home for a month."