Zoom GUI in fltk backend

[John W. Eaton]

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?

| 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?

jwe