Re: Zoom GUI in fltk backend

[Søren Hauberg]

tir, 21 07 2009 kl. 06:54 -0400, skrev Ben Abbott:
> On Jul 20, 2009, at 11:58 PM, Shai Ayal wrote:
> 
> > On Tue, Jul 21, 2009 at 6:53 AM, John W. Eaton<address@hidden> wrote:
> >> On 21-Jul-2009, Shai Ayal wrote:
> >>
> >> | It's not clear to me exactly what you tried, but panning is done by
> >> | dragging the mouse, zooming by using the mouse scroll wheel.
> >>
> >> Ah.  Duh.  I didn't think to try the scroll wheel.  What if I didn't
> >> have one?  I was expecting to be able to draw a rectangle and have  
> >> the
> >> plot zoom to that region.  Would it be hard to implement something
> >> like that?
> 
> In fact, my notebook (notebooks in general?) doesn't have a scroll  
> wheel. However, I do like using the scroll wheel to zoom when I have  
> one.

<off-topic>
I think most notebooks support some sort of wheel emulation. If I hold
down the middle while moving my trackpoint I get wheel emulation. Most
Touchpads also support wheel emulation by moving your finger around the
right-most edge of the pad.
</off-topic>

> > This was the previous behavior. I can make it user-definable but I
> > think we don't have a mechanism for setting backend specific settings,
> > so we'll have to agree on something before I can proceed.
> 
> Would it not be possible to support both a scroll wheel and click-drag- 
> release?

I think we should a toolbar with a 'zoom' button. When this is clicked
you should be able to zoom by clicking on the plot. This is what Matlab
does. But we could still allow for zooming using the wheel, which I
think is just wonderful.

> Also, how does one unzoom? ... double-click doesn't work for me (which  
> is how I'd do it in Matlab).

I think unzooming on double-clicks would be sensible.

> >>  ca=VALUE
> >>
> >> to be printed in the command window.  This looks like handle for the
> >> current axes object.  Is that just some debugging output?
> >
> > Yes, it's debugging. I'll try to hunt it down.

This is just something that is printed from within 'fltk-backend.cc'. I
don't know why it's there, but it is trivial to remove.

Soren