mouse zoom centred on mouse position.

[<pl...@pi...>]

Hi,

just a quick idea to throw into the air: I was using cntl-mouse_scroll 
to zoom in and out on  a long data series and found myself having to 
adjust left and right.

What  some graphics programs (and ggogleearth) do in this situation is 
to zoom on the mouse position.  This is a major improvement.

Put the mouse over the point of interest and zoom in and out. The point 
of focus under the mouse stays in the same position and the rest scales 
and shifts around it.

I guess this would not involve much change to the code since the zoom 
and the scroll is already there but in terms of usability it is a great 
help.

best regards, Peter.