Draggable columnrange inverted

[DamienFrancesProjet]

Here I have my chart :

http://jsfiddle.net/fh9k0k2g/3/

What is my problem ? I have two:

• I would like take a task and move it along the Yaxis (date because it is inverted)
• I would like take a task and expand it on one side or the other

So two action possible for one same object. It is for my job maybe with left or right mouse button.

Thank you a lot for your help :)