Path: utzoo!attcan!uunet!snorkelwacker!apple!AppleLink.apple.com!Greg
From: Greg@AppleLink.apple.com (Greg Marriott)
Newsgroups: comp.sys.mac.programmer
Subject: Re: Determining whether MultiFinder is present
Message-ID: <10649@goofy.Apple.COM>
Date: 10 Oct 90 10:34:38 GMT
Sender: usenet@Apple.COM
Organization: Apple Computer, Inc.
Lines: 46
References:<45479@apple.Apple.COM> <1990Oct9.203522.11201@cbnewsk.att.com>

In article <1990Oct9.203522.11201@cbnewsk.att.com> ech@cbnewsk.att.com 
(ned.horvath) writes:
> From article <45479@apple.Apple.COM>, by das@Apple.COM (David Shayer):
> > You probably know the standard answer to this:  You don't need to know.
> > Instead, check for the specific feature you need...
> 
> And you apparently need the standard rejoinder to this: if Apple 
programmers
> have a legitimate need to know (as Font/DA mover needs to know; as the
> LaserWriter needs to know so that it can selectively highlight the
> "Background Printing" button; but two ought to suffice), then non-Apple
> programmers have that very same need to know.
> ...
> depending on how determined Apple are to protect
> their monopoly on knowing if MF is running.
> 
> This is a silly game.  Can we stop now?
> 
> =Ned Horvath=
Can't stop yet... I just have a couple of points to add :)

Font/DA Mover, Laserwriter, and MF are System Software.  System 
Software can be as incestuous as it wants.  If the methods of 
implementation of features like MF change, then the rest of sys. software 
that "peeks" at it will change as well.  3rd party applications aren't 
afforded the same luxury.  If an app takes advantage of implementation 
details to provide services, it should be willing to handle the 
consequences of changes in the way features are done.

Apple has said (ad. nauseum) that 3rd parties should not check for MF.  
Actually, what this means is "Check all you want, but we might change it 
at any moment, so don't screw your users by counting on something that 
will break you in the future."  If you feel the need to check, then be 
prepared to limit your application to run ONLY on system versions where 
you a CERTAIN your check is valid.

Apple tries really hard not to chnage the way documented calls work.  
(Honest! :)  Even undocumented things undergo a great deal of study before 
they are changed... But, if DTS says "don't do this" it's for a good 
reason.  We're not protecting "a monopoly on knowing if MF is running", 
we're trying to protect future systems from architectural limitations 
based on current implementation details.

Greg Marriott
Blue Meanie
Apple Computer, Inc.