Java Tutorial/Swing Event/PropertyChangeListener

Listening to Component Events with a PropertyChangeListener

   <source lang="java">

import java.beans.PropertyChangeEvent; import java.beans.PropertyChangeListener; import javax.swing.Action; import javax.swing.Icon; import javax.swing.JButton; import javax.swing.JFrame; class ActionChangedListener implements PropertyChangeListener {

 private JButton button;
 public ActionChangedListener(JButton button) {
   this.button = button;
 }
 public void propertyChange(PropertyChangeEvent e) {
   String propertyName = e.getPropertyName();
   System.out.println(propertyName);
   if (e.getPropertyName().equals(Action.NAME)) {
     String text = (String) e.getNewValue();
     button.setText(text);
     button.repaint();
   } else if (propertyName.equals("enabled")) {
     Boolean enabledState = (Boolean) e.getNewValue();
     button.setEnabled(enabledState.booleanValue());
     button.repaint();
   } else if (e.getPropertyName().equals(Action.SMALL_ICON)) {
     Icon icon = (Icon) e.getNewValue();
     button.setIcon(icon);
     button.invalidate();
     button.repaint();
   }
 }

} public class PropertyListenerJComponent {

 public static void main(String[] a) {
   JFrame frame = new JFrame();
   frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
   JButton bn = new JButton();
   bn.addPropertyChangeListener(new ActionChangedListener(bn));
   frame.add(bn);
   bn.setEnabled(false);
   frame.setSize(300, 300);
   frame.setVisible(true);
   frame.add(bn);
 }

}</source>