Porting UNIX Applications to the Mac

[Larry Tesler]

In article <267 at uwmacc.UUCP> dubois at uwmacc.UUCP (Paul DuBois) writes:
>Mac users (some of 'em, anyway) like to talk about modeless
>operation, but let's not forget:  the mouse *IS* a mode.
>
>Modelessness is a myth, propagated sometimes by people who should
>know better.

If I can figure out how to use vi, I'll reply.  I agree that modelessness
is a technically vague term.  It could be argued that even a text editor
like MacWrite has one mode, "obey-next-input mode".  But if a program has
one mode, it has no mode changes, and thus we call it modeless.  It is
also arguable that a font change command produces a mode, but so does a
caps lock key; I call either a "shift", which, as modes go, is innocuous
because the effect of forgetting which mode you are in is certainly less
drastic than that of typing "23d Street" without first entering insert
mode in vi.

Depending on how you choose to define "mode", the mouse could be called a
mode, but then so could the "7" key on a typewriter.  A useful definition
of mode is a state of a user interface that affects the interpretation of
subsequent inputs without obvious indication.  It is possible on the Macintosh,
using clover keys, to bring up a dialog box and thus enter a mode unknowingly.
But it is exceedingly rare compared with systems like vi that overload the
typing keys with functional meanings.

Let me add that, although I agree vi is an obnoxious editor, I do think it
deals with the mode problem gracefully.  Bad keystrokes often beep, undo is
always available for one command, and most vowels enter insert mode so it is
difficult to type a word as a command.

Modelessness is not a myth.  Like "seamlessness" or "painlessness", it is an
ideal that may rarely be attainable but is always worth approximating.  The
alternative is surely inhumane computing.

Larry Tesler, Advanced Development Group, Apple Computer, Inc.
The opinions expressed above are my own although I suspect more than a few
colleagues, not to mention users, would substantially agree with them.