Re: "scrollwheel" kind of widget

["Gustavo J. A. M. Carneiro" <gjc inescporto pt>]

On Fri, 2005-03-18 at 16:53 +0100, Magnus Bergman wrote:
> >   I have made some modifications to the Gtk*Ruler widgets to obtain
> > similar goal, to incorporate in gnumexp[1] for selecting the area of a
> > math function to view.  I called it NxpRuler.  So it looks just like a
> a
> > normal gtk ruler, except that it highlights on mouse over, and you can
> > drag it around with button 1, and scale/stretch with button 3.
> >
> >   I'm very happy with the obtained result.  Already proposed to the
> Dia
> > developers to use this widget, a few years ago, but got no feedback :|
> > 
> >   Regarding the thumbwheel approach, yes, it does look more intuitive
> > for first-time users.  But I think the NxpRuler highlight on mouse
> over
> > (and maybe we could change cursor too) makes it obvious that this
> ruler
> > is special and can be interacted with.  Moreover, a ruler is very
> useful
> > to display distances, whilst the thumbwheel doesn't allow this.
> 
> I agree with you that irix-style thumpwheel is not the best solution. I
> don't like that is has a fixed size. And the design has too much
> character, it might not go well with every theme (and how should the
> theme engines really draw it?).
> 
> Finally I have installed gnumexp. And, yes, that was very similar to
> what I have in mind. But since it's function is to replace the
> scrollbar, I think it's slightly too different from the scrollbar. And
> the feature of scaling without keeping the aspect ratio I believe is
> more of a misfeature outside the mathematical field of application.

  OK, in gnumexp itself you scale both axis independently, without
preserving aspect ratio.  But I think the API itself supports scaling
while preserving aspect ratio, although it has been years since I wrote
this code, so I can't remember very well.

>  I
> guess a separate zoom function is is the better in most cases. I'll ask
> the usability people and see what they think.

  Yeah, I guess I'm not an usability expert, so I can't really tell
what's best.

> 
> Applications such as Dia was also what I had in mind. I made a mockup of
> how I imagined that the widget could look like (in applications such as
> Dia).

  Yeah, I guess a ruler is too different from scroll bar.  But I really
love the position triangle, and the tick marks with numbers.  It's
really great having this for some types of programs, like math,
schematics, or drawing programs.  And the scroll arrows at the edges
break this scheme.  I guess it's a learning curve vs functionality
issue...

>  I hope nobody minds that I post pictures to the list?

  It depends on the file size.  this one is really small (2.1K), it's
OK.

  Best regards.

-- 
Gustavo J. A. M. Carneiro
<gjc inescporto pt> <gustavo users sourceforge net>
The universe is always one step beyond logic