Container.java 文件源码

/**
 * Adds a PropertyChangeListener to the listener list.
 *
 * @param listener  the PropertyChangeListener to be added
 */
public void addPropertyChangeListener(PropertyChangeListener listener) {
    if (accessibleContainerHandler == null) {
        accessibleContainerHandler = new AccessibleContainerHandler();
    }
    if (propertyListenersCount++ == 0) {
        Container.this.addContainerListener(accessibleContainerHandler);
    }
    super.addPropertyChangeListener(listener);
}