Re: [Usability] Tab consistency

[Calum Benson <Calum Benson Sun COM>]

On Fri, 2007-03-30 at 13:14 -0500, Matthew Nuzum wrote:
> On 3/30/07, Shaun McCance <shaunm gnome org> wrote:
>         They need to do their homework.  In GTK+, Ctrl+Tab moves focus
>         between groups of widgets.  It's sort of a souped up version
>         of
>         Tab, and it has the distinct advantage of actually working in
>         a
>         multiline text editor, where Tab just inserts a tab
>         character. 
>         
>         Given that we've used Ctrl+Tab for this purpose for a long
>         time,
>         and given that we've used Ctrl+PageUp/PageDown for switching
>         tabs
>         for an equally long time, I don't think it's likely we'll
>         change.
> 
> Ctrl+Tab has been used for ages as the way to switch between windows
> in MDI interfaces on MS Windows.

IIRC you can do this with Alt+F6 too (at least I think that works in MDI
apps as well; whether it does or not, it does admittedly include any
open dialogs in the chain too). That's probably a more widely-accepted
standard, having been first defined back in IBM's CUA guidelines, if not
before-- so it works in GNOME (since quite recently) and on other
platforms as well.

Ctrl+PageUp/PageDown is used in Windows tabbed dialogs, not to mention
other toolkits we assessed at the time.  So for consistency, we chose to
use that for all our tab-switching needs, dialog or otherwise, as we
wanted to use Ctrl+Tab for other purposes.  (We've since also made Ctrl
+Alt+PageUp/PageDown work too, as Ctrl+PageUp/PageDown can sometimes be
consumed by other focused widgets on a tabbed page.)

FWIW, you can look at the original keynav comparison documents we put
together here:
http://developer.gnome.org/projects/gap/keyboardnav.html

You could certainly argue that they're due a revisit (developers have a
habit of sneaking in esoteric new keynav features without really telling
the people they ought to tell). But it's been a very large (and ongoing)
task to achieve the level of keynav coverage and self-consistency we
have today, so any potential changes need to be considered very
carefully indeed, as the knock-on effects aren't always immediately
obvious.  (Partly because we don't have a good developer-centric
database of existing keyboard shortcuts-- although we do have a
reasonable user-centred one, see below.)

> How do you communicate that Ctrl+Tab switches between groups of
> widgets? 

It's not actually supposed to generically 'switch between groups', it's
just supposed to bail you out of a widget where Tab has another function
(text widgets and certain panel applets, primarily)[1]. It's documented
along with all the other gtk and GNOME keyboard shortcuts in the
keyboard chapter of the GNOME Accessibility Guide.  (Yes, I'd kind of
like to see this chapter moved to the main user guide too, where if
nothing else it might be better-maintained.)

http://www.gnome.org/learn/access-guide/latest/keynav-1.html

Cheeri,
Calum.

[1] This is a long-standing keynav gripe of mine-- IMHO, shortcuts that
are intended for specific purposes (like Ctrl-Tab), or that only work in
some situations and not others (e.g. arrow keys for moving focus--
broken leftovers from gtk 1.x mostly, arrow keys were never in the
keynav spec for 2.x), shouldn't really do anything else at all.  But
because they do, and people then stumble across them accidentally, they
can get the wrong idea about what they're actually supposed to do.  And
then they complain when they don't do that. Ho hum.

-- 
CALUM BENSON, Usability Engineer       Sun Microsystems Ireland
mailto:calum benson sun com            GNOME Desktop Group
http://ie.sun.com                      +353 1 819 9771

Any opinions are personal and not necessarily those of Sun Microsystems