Returns a <code>Point</code> whose x coordinate is the
character position representing the start of the selection
in the receiver's text field, and whose y coordinate is the
character position representing the end of the selection.
An "empty" selection is indicated by the x and y coordinates
having the same value.
<p>
Indexing is zero based. The range of a selection is from
0..N where N is the number of characters in the widget.
</p>
@return a point representing the selection start and end
@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 a <code>Point</code> whose x coordinate is the character position representing the start of the selection in the receiver's text field, and whose y coordinate is the character position representing the end of the selection. An "empty" selection is indicated by the x and y coordinates having the same value. <p> Indexing is zero based. The range of a selection is from 0..N where N is the number of characters in the widget. </p>
@return a point representing the selection start and end
@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>