Re: [Usability] sticky keys and alt-tab

[Shaun McCance <shaunm gnome org>]

On Wed, 2006-09-13 at 10:26 +0200, Maurizio Colucci wrote:
> On 9/13/06, Maurizio Colucci <maurizio colucci gmail com> wrote: 
>         On 9/12/06, Elijah Newren <newren gmail com> wrote:
>                 On 9/12/06, Maurizio Colucci
>                 <maurizio colucci gmail com> wrote:
>                 > Hello,
>                 >
>                 > if I enable sticky keys (control panel -> keyboard
>                 -> accessibility), I 
>                 > loose the ability to ALT-TAB (unless, of course, I
>                 keep ALT pressed, which
>                 > defeats the purpose of using sticky keys). Is there
>                 any way to switch the
>                 > active window with the keyboard  which does not
>                 require holding buttons? 
>                 > Thanks for any help.
>                 
>                 If you have sticky keys enabled, you should be able to
>                 "make alt be
>                 pressed and held" (not sure if this has a technical
>                 term) by hitting
>                 alt twice.  Then hit tab however many times you
>                 need.  Then "release 
>                 alt" by hitting alt again.  In other words, to get the
>                 behavior
>                 equivalent to
>                    <press-alt>-<tab>-<tab>-<tab>-<release-alt>
>                 but with sticky keys, you would instead use the key
>                 sequence 
>                    <alt>-<alt>-<tab>-<tab>-<tab>-<alt> 
>         
>                 Hope that helps, 
>         
>         It would, if it worked. Unfortunately it does not work at all.
>         Pressing ALT twice is no different than pressin it once for
>         me. I am using the USA keyboard layout, Gnome is the one in
>         Ubuntu Dapper. Any ideas? Thank you. :-)
> 
> Never mind, I found the problem: in keyboard preferences -> layout
> options -> group/shift-lock behavior, I had to disable "both alt keys
> together change group". However this does not make much sense, since I
> was not pressing both alt keys together. Is this a bug? 

I don't think it's so much a bug as it is a peculiar set of
interactions that just don't work out well together.  Look
at pressing both Alt keys together as pressing Alt+Alt.
That is, one Alt is a modifier, while the other Alt is the
thing it modifies.  With sticky keys, you would type this
by pressing Alt, then pressing Alt again.

It would seem the underlying code doesn't really check if
the two Alt key presses were different Alt keys, probably
because the programmers weren't thinking about sticky keys
when they wrote it.  (How else would you press the same
key at the same time as itself?)

This is, I believe, all XKB stuff, which is black magic
to most of us.

--
Shaun