Re: [HCI] Focus navigation with arrow keys

[Bill Haneman <Bill Haneman Sun COM>]

Hi folks:

One complication with modifiers, which is actually a major concern,
is that many of the users who most urgently require keyboard
navigation, like those with limited mobility, cannot easily
use keyboard modifiers.  Although utilities like AccessX allow
the modifier keys to become "sticky", making it possible for
a user to press "alt-shift-arrow" as three separate keystrokes,
this means at least trebling the effort that for instance, a 
quadraplegic using a mouth-held device must exert.  

You see the problem.  The navigation keys need to _simplify_
the operation rather than complicate it, where possible.

One option is to allow alternates to all of the "pre-bound"
keys like arrow and tab which an app or widget would like to 
grab.  We don't want to make users learn new focus traversal 
keybindings for different widgets and apps.  Think of it this
way: context or widget-specific behaviors will have to be learned 
by the user on a per-app basis anyway - so why override a small 
set of commonly-used keys at the expense of consistency in
"standard" actions like widget traversal, selection, and 
activation?  If an application can show a strong HCI reason
for grabbing these common keys (like, for instance, 
the arrow keys in a mult-line text entry field), there should
be alternates available, and a configurable way to turn off 
the widget's overriding of standard keystrokes at the user's 
request.  At the very least there should be a GUI-wide
way of turning on standard traversal keybindings, and 
insisting on always providing alternates when TAB, arrow, 
spacebar, etc. are grabbed by the widget might be the most
expedient solution.

It would be really nice if apps and toolkits had already
agreed on standard keybindings, of course this isn't the
case.  But there are several to choose from ;-), at the
very least we should try to pick one instead of letting
each widget do it's own thing.

Best regards,

-Bill

Pavel said, in response to Owen:

>Hi!
>
>> I think the first problem makes this capability pretty useless
>> with the current key bindings. We could have different keys
>> that _always_ moved the focus, but finding a modifier+arrows
>> combination that:
>> 
>>  A) is not already in use.
>> 
>>  B) Users will have some chance of discovering.
>
>You can actually _tell_ users. Providing help page with "usual
>keybindings" would be great.
>
>> Seems a little difficult. (Control-arrows, Shift-arrows
>> are standard CUA bindings. Combinations of multiple-modifiers
>> plus arrows are frequently used by window managers, and
>> are obscure in any case.)
>
>Current keyboards have "windoze" key and menu key, usable as
>modifiers, too.
>								Pavel


------
Bill Haneman x19279
Gnome Accessibility / Batik SVG Toolkit
Sun Microsystems Ireland