void onMouseDoubleClick (Event event) {
	if (!isFocusControl ()) setFocus ();
	int index = (event.y - getHeaderHeight ()) / itemHeight + topIndex;
	if  (!(0 <= index && index < itemsCount)) return;	/* not on an available item */
	CTableItem selectedItem = items [index];
	
	/* 
	 * If the two clicks of the double click did not occur over the same item then do not
	 * consider this to be a default selection.
	 */
	if (selectedItem != lastClickedItem) return;

	if (!selectedItem.getHitBounds ().contains (event.x, event.y)) return;	/* considers x */
	
	Event newEvent = new Event ();
	newEvent.item = selectedItem;
	notifyListeners (SWT.DefaultSelection, newEvent);
}