Returns the column which shows the sort indicator for
the receiver. The value may be null if no column shows
the sort indicator.
@return the sort indicator
@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 column which shows the sort indicator for the receiver. The value may be null if no column shows the sort indicator.
@return the sort indicator
@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 #setSortColumn(TableColumn)
@since 3.2