Path: utzoo!utgpu!watmath!clyde!att!osu-cis!tut.cis.ohio-state.edu!ukma!rutgers!cmcl2!esquire!sbb
From: sbb@esquire.UUCP (Stephen B. Baumgarten)
Newsgroups: comp.sys.mac
Subject: Re: multitasking and IPC
Message-ID: <935@esquire.UUCP>
Date: 19 Dec 88 22:15:37 GMT
References: <1988Dec16.191309.21623@cs.rochester.edu> <326@internal.Apple.COM> <264@berlin.acss.umn.edu> <329@internal.Apple.COM>
Reply-To: sbb@esquire.UUCP (Stephen B. Baumgarten)
Organization: DP&W, New York, NY
Lines: 81

In article <329@internal.Apple.COM> goldman@Apple.COM (Phil Goldman) writes:
[ About why when an application demands the user's focus of attention
  with a modal dialog box, the user cannot switch out of the application. ]

>No.  This is a user interface decision.  I understand your argument, but it
>does not come down to a single- vs. multitasking decision.  Rather, it is
>a decision on how much power to give to the application.
>
>Also, remember that compatibility includes user interface compatibility as well.

The time people most want to switch out of an application is when
they're faced with an open or save file box and can't remember where
they put a file, or want to rename a file, or want to delete a file,
etc.  And it's at that very point that Apple takes away their ability
to switch to the Finder.

If you doubt this, look at the number of utilities that help patch the
standard open and save dialog boxes (Findswell, HFS Navigator, etc.),
and look at how popular they are.

People intuitively understand why their work on a particular
application (computer and otherwise) must wait until a crucial piece of
information is obtained.  I'm sure people would be quite confused if
they started to open a file, got the standard open box, and then went
right back to working on their document, leaving the open dialog box on
the screen somewhere.  No one has a problem with having an application
wait on them to select a file name.

But in everyday life people are faced with this situation all the time,
and never do they suspend everything else they are doing if they don't
have to.  For example, I'm writing Christmas cards now.  I'm about to
mail a letter, but I can't remember my friend's address.  So my ability
to mail the letter must now wait on a piece of information I don't have
at the moment.

In real life, I now put my pen down, pick up my address book and look
up the address.  Or I might just leave it altogether and play a game.
Of course, the letter still remains on my desk, unaddressed, and I
still can't mail it until I find my friend's address somewhere.

On the Mac, I'm stuck.  I can't continue in the "mail" application
until I have the address, but on the other hand, I can't switch to my
Rolodex program to find the address unless I first tell the "mail"
program to cancel the "mail it" operation (i.e., dismiss the "save"
dialog box).  Somewhat counter-intuitive, since canceling the "mail it"
operation is exactly what I *don't* want to do.

Watch beginning Mac users use MultiFinder.  You see them click on the
mini-icon in the menu bar to switch applications during opens, during
saves, even during a session with the Font/DA Mover.

This may be a compatibility issue or there may be technical reasons for
it (e.g., the Font/DA Mover might have the System file in an
inconsistent state or something), but I don't think it could possibly
be a user-interface issue.

In fact, the Font/DA Mover is a good example of something that was
designed for technical reasons but never intended as an example of a
"user-interface" decision.  It's a kludge, and people don't understand
it or how it works, because its operation is so different than the
standard "Finder" style of doing things (Servant really was much better
than MultiFinder in this respect).

On the other hand, no one at Apple ever justified the Font/DA Mover's
existence by claiming that it was designed with user-interface issues
in mind.  It was just a side-effect of having to work within the severe
hardware and software limitations of the original Macintosh (just like
the original disk copy program that used screen memory).

Sorry I'm going on and on about this, but regardless of whether
MultiFinder as it now is is better or worse than pre-emptive
multitasking, I think it's worth keeping in mind that users don't like
to be "moded-in" any more than they have to be, and that we should
therefore be careful before justifying technical hacks (even if they
are brilliant, fully-functional hacks) on user-interface grounds.

-- 
   Steve Baumgarten             | "New York... when civilization falls apart,
   Davis Polk & Wardwell        |  remember, we were way ahead of you."
   cmcl2!esquire!sbb            | 
   esquire!sbb@cmcl2.nyu.edu    |                           - David Letterman