Path: utzoo!utgpu!news-server.csri.toronto.edu!rpi!batcomputer!cornell!uw-beaver!mit-eddie!mintaka!think.com!spool.mu.edu!samsung!usc!ucsd!ucbvax!ucdavis!csusac!unify!openlook!openlook-request
From: openlook-request@openlook
Newsgroups: comp.windows.open-look
Subject: Re: Searching a scrolling list
Message-ID: <b6mtscq@openlook.Unify.Com>
Date: 14 May 91 20:15:37 GMT
Article-I.D.: openlook.b6mtscq
Lines: 42

> The question is this: according to OPEN LOOK style, what is the best way to
> present both access methods --- type-in and list selection --- so that users
> can use either one or both, as suits them?

[This seems too easy, Kerry, what am I missing?]

I suggest implementing a scrolling list next to a text field.
When a user selects an item from the scrolling list, display
it in the text field; when the user enters a value into the
text field, select it in the scrolling list (or, if not a valid
item, complain).

On occasion I find a more complex (for the implementor) u.i. more
appropriate: For a selection u.i. that requires frequent interaction,
give an abbreviated menu button with a short list of choices, plus
an extra (oblong) button. The short list gives those choices
most often picked by users, the extra button gives access to a
popup window with the scrolling list of all choices. For those who
like to type in a value, either put the text field next to the
abbreviated menu button (when users often want to type in a value),
or next to the popup's scrolling list (when users don't usually
need to type in a value). An enhancement includes a way to let
the user pick which items show up in the short menu.

Note: If you use the more complex u.i., put the short list in
an exclusive (or non-exclusive) choice control; and make the
extra button a regular, oblong-shaped button.
    
> Toolkit implementors: the ideal would be a scrolling list that would scroll as
> you typed, much like Emacs incremental search: Hit 'F' and the first item
> beginning with 'F' is highlighted, etc.

Neat idea. We suggested this to Tony Hoeber, et al, when they
were designing the scrolling list.  I don't recall exactly why
they chose the each-typed-character-matches-the-1st-letter
u.i., instead of the incremental approach. I think it may have
been that other GUIs used the single-letter match; this method
is very similar to the mnemonics/accelerators used to operate
other controls in most GUIs.

Steve Humphrey
UNIX System Laboratories