/**
* Add a property change listener.
*
* @param l the listener to add
*/
public synchronized void addPropertyChangeListener(PropertyChangeListener l) {
if (support == null)
synchronized (this) {
// new test under synchronized block
if (support == null) support = new PropertyChangeSupport(element);
}
support.addPropertyChangeListener(l);
}
/**
* Remove a property change listener.
*
* @param l the listener to remove
*/
public void removePropertyChangeListener(PropertyChangeListener l) {
if (support != null) support.removePropertyChangeListener(l);
}
/**
* Fires property change event.
*
* @param name property name
* @param o old value
* @param n new value
*/
protected final void firePropertyChange(String name, Object o, Object n) {
if (support != null) support.firePropertyChange(name, o, n);
}