if (propertyChangeListener == null) {
propertyChangeListener = new IPropertyChangeListener() {
public final void propertyChange(
final PropertyChangeEvent propertyChangeEvent) {
final String property = propertyChangeEvent.getProperty();
fireHandlerChanged(new HandlerEvent(ActionHandler.this,
IAction.ENABLED.equals(property), IAction.HANDLED
.equals(property)));
}
};
}