public SingleFrameApplication() {
super();
History.addValueChangeHandler(new ValueChangeHandler<String>() {
public void onValueChange(ValueChangeEvent<String> event) {
final ActionMap actionMap = getContext().getActionMap();
final Action action = actionMap.get(event.getValue());
if (action != null) {
action.actionPerformed(new ActionEvent(action,
Application.getInstance()));
}
}