}
public void update(Observable o, Object arg) {
if (arg == null) {
this.removeAllPanels();
SelectionModel model = (SelectionModel) o;
if (!model.isSelectionEmpty()) {
Iterator<SelectionItem> itemsIt = model.getCurrentSegments().iterator();
while (itemsIt.hasNext()) {
SelectionItem selectItem = itemsIt.next();
if (selectItem.isSelected()) {
this.addSegment(selectItem.getIndexSegement());
}