[HIG] Re: Instant apply (and an HIG change)

[Seth Nickell <snickell stanford edu>]

Just to clarify... There are cases where instant apply is not
appropriate. Non instant apply dialogs should also be spec'd in the HIG.

> 1) Instant apply works very poorly when the apply operation is
> especially expensive, such as with metatheme.

The number of operations where this is true is fairly small though.
Especially because most operations on the computer should really be kept
within the 1.0 second range as it is. See:

http://usability.gnome.org/hig/draft_hig/acceptable-response-times.html

Some operations like changing the methatheme are still too expensive.
But wherever possible we should work toward making them cheap enough to
handle this way...whether instant apply were used or not. In the case of
metatheme I would recommend using a non-instant-apply dialog.

> 2) Certain controls on the mouse capplet don't work too well with
> instant apply, such as the left-handed check box and the acceleration
> feature (e.g. consider what happens if a user accidentally drags the
> acceleration bar all the way to the right).

I don't think it causes user problems here. Neither extreme of the mouse
acceleration should be so much that the computer is not usable. I played
with a neighbor's Mac to see how this plays out, and it seems to work
fine on the Mac. If I drag the slider all the way to the left and drop
it "by accident", its slow enough that its a little bit annoying to
change back again. But certainely not a big problem.

> 3) Instant apply can be disasterous with system tools, such as the
> Ximian Setup Tools.

Yes, but many system tools *can* be instant apply. Most MacOS/X system
settings are instant apply, for example. For the few that could be more
dangerous they put "Apply" style buttons near them. This seems pretty
reasonable overall.

> 4) To be effective, it should be applied consistently to all capplets.
> If some capplets are of the instant apply variety and others are not, I
> forsee much confusion on the part of the user.

This is probably where we mostly disagree. I think having two "styles"
is fine as long as there are only two and they are consistent and well
followed. The dialog style should be slowly phased out as it becomes
more feasible to implement things as instant apply.

> > OK. I'm not thrilled about doing extra work that could be spent elswhere
> > on the GNOME2 beta for something I see as being of dubious value, but
> > I'll convert the background properties page tonight if I have time.
> 
> I hope that my work on property editors has mitigated that somewhat.

Unfortunately property editors don't work for a number of the elements
of the background properties page where more detailed interaction is
required. They're really nice for the elements they can support though!

-Seth