Zoom GUI in fltk backend

[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<jwe at octave.org> 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.

> 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?

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

>> | clicking should have no effect
>>
>> It seems to cause something like
>>
>>  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.

BTW, I get

octave:1> backend('fltk')
octave:2> x = 10:0.01:10;
octave:3> plot(x,sin(x))
octave:4> ca=nan
ca=nan
ca=nan
ca=nan

octave:4> axis auto
octave:5> ca=nan
ca=nan

I'm running fltk 1.1.9, with the current sources (thus zooming is by  
click-drag-release).

Ben