Mouse wheel scrolling with tabs

Currently, scrolling through tabs requires clicking on the left/right arrow 
buttons of a Jx.Toolbar.Container.
I suggest to also support the mouse's wheel movements on the toolbar container, 
so that :
- scrolling the mouse's wheel upward acts like a click on the scrollLeft button,
- scrolling the mouse's wheel downward acts like a click on the scrollRight 
button.

I don't think it's necessary to activate the tabs when scrolling (no need to 
fireEvent anything), but simply proxy the mouse wheel events to the 
scrollLeft/scrollRight buttons as click events (which *may* in turn fire events 
as needed).

Mootools has native support for the "mousewheel" event (using "mousewheel" or 
"DOMMouseWheel" depending on the browser). See 
http://mootools.net/demos/?demo=MouseWheel for more information.

The following steps can be used as a test for this feature:
1. Create a set of tabs in a TabBox so that the combined width of all the tabs 
is wider than the width of the TabBox's container.
2. Two buttons are automatically added (left/right arrows) to allow you to 
scroll through the tabs (so far, so good).
3. Try to scroll using the mouse's wheel on the bar where the tabs' names are 
displayed.

* why is this feature desirable?
Potentially makes navigation easier. At least, makes it more inline with that 
of a desktop application (eg. Firefox or any other Multiple Document Interface 
with many open tabs).

* what components of the library are affected?
Jx.Toolbar.Container

* does it change the existing API in any way?
No.

* does it require documentation changes?
Maybe, just add a note saying that the mouse's wheel is supported.

* does it require changes to the examples?
No.
Original issue reported on code.google.com by fpoirotte@gmail.com on 13 Feb 2011 at 4:14
Letractively / jxlib

Mouse wheel scrolling with tabs #211
