[Usability] Re: [Gimp-developer] Redo shortcut (was: Undo shortcut)

[David Neary <dneary free fr>]

 Marc A. Lehmann  wrote:
> On Wed, Sep 24, 2003 at 11:39:44PM +0200, David Neary <dneary free fr> wrote:
> > I'm sure that ergonomy was considered for Photoshop when they
> > chose Ctrl-Shift-Z for Redo... I do think it's overstating our
> > importance somewhat to say that what's good for a large portion
> > of the rest of the world is not good for us.
> 
> "Others do it" is never an argument, though.

It's an argument, just not a very good one (on its own). "Others
do it, because it's been shown to be the best way" would be a
decent argument, for example (I'm not arguing this).

In the current situation, I think it's reasonable to fit in with
what others do in the general case, which dynamic shortcuts
provide a way to revert to the old behaviour. When the others are
everyone using a Mac, plus people who come to the GIMP from KDE
or GNOME applications, and PhotoShop users, I think the benefits
of a familiar keybinding are self-evident. 

If you like, I'm arguing populism here. More people use 
Ctrl-Shift-Z as redu than Ctrl-R. Therefore, until there is a very 
good reason to change, we should do the same. In addition, a
considerable body of usability work reccommends this keymapping.

> What you need are arguments in favour of Ctrl-Shift-Z, and the only ones
> that there are is "the HIG and other platforms use it, so people are
> probably used to it, making it easier for them to switch".

Yes, that's about it. It's also that current GIMP users probably
benefit from having the same keybindings everywhere. There's
nothing that annoys me more than using emacs, getting back into
the emacs keybindings, and then using vim, and freezing the
terminal with C-x C-s. Of course, this is not like with like. But
I imagine that people who use both the gimp and photoshop have
dozens of little annoyances like these.

> That is one aspect of usability. It doesn't have much to do with
> ergonomics, and as others already have said, Ctrl-R/Ctrl-Z is much more
> ergonomical than three-key-combinations.
> I think "two keys vs. three keys" is extremely obvious, too.
> So ergonomics is might have been considered, but it was certainly
> _dismissed_, as other, much more ergonomic combinations, are available.

You have a point here. I think that what was chosen was the
consistency of Shift as negation. I think that's probably a goal
we could work towards. It certainly makes a lot of logical sense.
But then, so does having + to zoom in instead of =, and look how
many bug reports that's got us :)

> > And the usability people have considerably more experience with this
> > than either of us :)
> 
> usable != ergonomic, though.

Fair enough.

> And I think that gimp users have considerable more experience with using
> gimp than the usability people.

If the GIMP were the only graphics application choosing this
keybinding I would agree. I guess that when in doubt, following
the crowd is a fairly safe bet (note this leaves open the
possibility of not following the crowd when not in doubt ;).

Cheers,
Dave.

-- 
       David Neary,
       Lyon, France
  E-Mail: bolsh gimp org