Core Swing Components - The Definitive Guide to Java Swing - page 78

} else if (e.getPropertyName().equals(Action.SMALL_ICON)) {
Icon icon = (Icon)e.getNewValue();
button.setIcon(icon);
button.invalidate();
button.repaint();
}
}
}

■ Note You can bind a PropertyChangeListener to a specific property by adding the listener with

addPropertyChangeListener(String propertyName, PropertyChangeListener listener) .
This allows your listener to avoid having to check for the specific property that changed.

Listening to JComponent Events with a VetoableChangeListener
The VetoableChangeListener is another JavaBeans listener that Swing components use.
It works with constrained properties, whereas the PropertyChangeListener works with
only bound properties. A key difference between the two is that the public void
vetoableChange(PropertyChangeEvent propertyChangeEvent) method can throw a
PropertyVetoException if the listener doesn't like the requested change.

public interface VetoableChangeListener extends EventListener {
public void vetoableChange(PropertyChangeEvent propertyChangeEvent)
throws PropertyVetoException;
}

■ Note Only one Swing class, JInternalFrame , has constrained properties. The listener is meant primarily for
programmers to use with their own newly created components.

Listening to JComponent Events with an AncestorListener
You can use an AncestorListener to find out when a component moves, is made visible, or is
made invisible. It's useful if you permit your users to customize their screens by moving
components around and possibly removing components from the screens.

public interface AncestorListener extends EventListener {
public void ancestorAdded(AncestorEvent ancestorEvent);
public void ancestorMoved(AncestorEvent ancestorEvent);
public void ancestorRemoved(AncestorEvent ancestorEvent);
}