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

[David Neary <dneary free fr>]

Nathan Carl Summers wrote:
> I agree.  Gimp's undo and redo feature differs from many other programs in
> that when comparing subtle changes it is useful to switch rapidly between
> the "before" and "after" views, while for a program such as a word
> processor, that is probably not a useful thing to do.  This being the
> case, this particular need of GIMP users was probably not considered by
> the HIG.

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.

> Personally, I compare between the "before" and "after" by holding down
> control and hitting z or r as necessary.  For some changes, I switch
> several times a second, as the human eye is remarkably able to detect
> small differences when they are animated.

You will be able to continue to do this, using the Wonders of
Dynamic Shortcuts. However, I think that in the general case we
should try to adhere to the keybindings which people expect if
they have used other applications (and not just imaging
applications).

> Switching between views this fast with accuracy is simply not possible
> using Shift-Ctrl-Z due the the physiology of the human hand. The optimal
> hand position is left on the shift and control and right on the z, with
> the finger on the shift moving every other beat of the other hand and the
> finger on the control key staying still.

That depends where the z is on the keyboard :)

> > So, if it's possible to have two different keybindings for the same command
> > I'd like very much to have both.
> 
> Unfortunately, it is not.  Really, GTK should be made more flexable in
> this regard, but it is not a trival problem, due to how GTK handles
> accelerators.

I believe we could hard-code two keybindings to work as the
default, couldn't we? Then if the keymapping is changed, you're
on your own. Perhaps I'm talking through my hat here.

> I'm sure that in this case most usability people would
> say that actually being able to use the feature is more important than
> consistancy with some other apps.  Especially because this particular
> funciton isn't particularly consistant between apps.

It's pretty consistent. And the usability people have
considerably more experience with this than either of us :)
I've added the usability list as a CC to see what they think.

Cheers,
Dave.

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