Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!bloom-beacon!apple!Apple.COM!lsr
From: lsr@Apple.COM (Larry Rosenstein)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Checking for MF (was Re: Need some MF help)
Message-ID: <1202@internal.Apple.COM>
Date: 6 Apr 89 02:42:42 GMT
Sender: usenet@Apple.COM
Distribution: comp.sys.mac.programmer
Organization: Objects-R-Us,  Apple Computer, Inc.
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References:<1562@neoucom.UUCP> <28689@ucbvax.BERKELEY.EDU> <1179@internal.Apple.COM> <12910@dartvax.Dartmouth.EDU>

In article <12910@dartvax.Dartmouth.EDU> earleh@eleazar.dartmouth.edu 
(Earle R. Horton) writes:
> I have MPW Shell 2.0.2, and it obviously knows whether Launch will
> return or not, and therefore knows whether MultiFinder is active.  It

As someone pointed out (and is mentioned in the Tech Notes), there is no 
approved way to know if the Launch trap will return or not.  As Phil 
Goldman mentioned, this is being fixed.  

If your application launches programs and cares about this (as does MPW) 
then there is currently no alternative.  Such applications are relatively 
uncommon, and Tech Support discourages people from writing such 
applications.  

I would go so far as t osay MPW is folowing the rules.  It is checking for 
a particular system feature and altering it behavior depending on whether 
it is present or not.  The only problem is that there is no 100% approved 
mechanism for making this test.

As always the price for not following the rules is possibly having to rev 
your program for a new system.  Presumably, MPW uses the best known 
technique for detecting whether Launch can return, which means it has a 
reasonable chance of being compatible with future systems.



Larry Rosenstein, Apple Computer, Inc.
Object Specialist

Internet: lsr@Apple.com   UUCP: {nsc, sun}!apple!lsr
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