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Path: utzoo!mnetor!uunet!mcvax!ukc!strath-cs!glasgow!gilbert
From: gilbert@cs.glasgow.ac.uk (Gilbert Cockton)
Newsgroups: comp.sys.mac,comp.windows.misc
Subject: Re: 2 button mouse
Message-ID: <1013@crete.cs.glasgow.ac.uk>
Date: 21 Apr 88 12:52:36 GMT
References: <4129@hoptoad.uucp> <283@rhesus.primate.wisc.edu> <1710@ssc-vax.UUCP> <201@glenlivet.hci.hw.ac.uk> <1798@sugar.UUCP>
Reply-To: gilbert@cs.glasgow.ac.uk (Gilbert\ Cockton)
Organization: Comp Sci, Glasgow Univ, Scotland
Lines: 36
Keywords: window human computer interface

In article <1798@sugar.UUCP> peter@sugar.UUCP (Peter da Silva) writes:
>Why are you always going to run out of mouse-buttons?
Excuse my elipsis - if you want to keep a one-to-one mapping between
button presses and logical operations (e.g. select, extend-select,
move, stretch, pop-up-a-menu, help etc. etc.), then you need a mouse
button for every logical operation.  If you have less buttons than
operations, you will end up with modes and memory problems. The three
button mouse workstation I'm using at the moment can get very modey
with the meaning of its buttons.

So, *for one-to-one mappings* (a good thing *all things being equal*)
new operations are bound to exhaust the supply of mouse buttons.  Note
that no-one with any sense would think that closure is possible with
any creatively designed artefact, so we can continue to expect innovation
in the fundamental logical operations encountered in graphical interfaces.

Again, the advantage of chording with keyboard and mouse is that the
supply of 'logical' mouse buttons is increased.  The alternative is to
have moded interpretation of mouse presses, or to map logical
operations onto icons (e.g. zoom box, quit box) or window zones (e.g.
move (un)constrained zones, scroll bars).  There is a bandwidth problem
here too, as eventually windows are going to get cluttered,
complicated and intimidating if a growing set of logical operations
is forever mapped onto new graphical controls.  Less workspace will
also become available as the borders of windows grow into complex structures.

Although the respondent rarely uses his keyboard, this cannot be the
case for programs such as spreadsheets (need the keypad), text
processors and programming environments (need the whole keyboard).
My feeling is that applications where the keyboard is essential are
used for far more person-interaction-hours than applications where a
keyboard is not essential. 

If the chording keys were duplicated down both sides of the keyboard,
mouse-keyboard chording could be simplified, indeed you could probably
have the necessary keys sticking out of the keyboard garage by the CPU!