Returns the direction of the sort indicator for the receiver.
The value will be one of <code>UP</code>, <code>DOWN</code>
or <code>NONE</code>.
@return the sort direction
@exception SWTException <ul>
<li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li>
<li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li>
</ul>
Returns the direction of the sort indicator for the receiver. The value will be one of <code>UP</code>, <code>DOWN</code> or <code>NONE</code>.
@return the sort direction
@exception SWTException <ul> <li>ERROR_WIDGET_DISPOSED - if the receiver has been disposed</li> <li>ERROR_THREAD_INVALID_ACCESS - if not called from the thread that created the receiver</li> </ul>
@see #setSortDirectioncast(int)
@since 3.2