Managing Listener Lists with AWTEventMulticaster : Event « Swing Event « Java Tutorial

Managing Listener Lists with AWTEventMulticaster
import java.awt.AWTEventMulticaster;
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.KeyListener;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import java.awt.event.MouseListener;
import javax.swing.JComponent;
import javax.swing.JFrame;
import javax.swing.JTextField;
public class KeyTextComponent extends JComponent {
  private ActionListener actionListenerList = null;
  public KeyTextComponent() {
    KeyListener internalKeyListener = new KeyAdapter() {
      public void keyPressed(KeyEvent keyEvent) {
        if (actionListenerList != null) {
          int keyCode = keyEvent.getKeyCode();
          String keyText = KeyEvent.getKeyText(keyCode);
          ActionEvent actionEvent = new ActionEvent(this, ActionEvent.ACTION_PERFORMED, keyText);
    MouseListener internalMouseListener = new MouseAdapter() {
      public void mousePressed(MouseEvent mouseEvent) {
  public void addActionListener(ActionListener actionListener) {
    actionListenerList = AWTEventMulticaster.add(actionListenerList, actionListener);
  public void removeActionListener(ActionListener actionListener) {
    actionListenerList = AWTEventMulticaster.remove(actionListenerList, actionListener);
  public boolean isFocusable() {
    return true;
  public static void main(String[] a){
    JFrame frame = new JFrame("Key Text Sample");
    KeyTextComponent keyTextComponent = new KeyTextComponent();
    final JTextField textField = new JTextField();
    ActionListener actionListener = new ActionListener() {
      public void actionPerformed(ActionEvent actionEvent) {
        String keyText = actionEvent.getActionCommand();
    frame.add(keyTextComponent, BorderLayout.CENTER);
    textField.setText("Press keyboard after clicking the above blank area");
    frame.add(textField, BorderLayout.SOUTH);
    frame.setSize(300, 200);

15.1.1.In the event model, there are three participants
15.1.2.Subclasses of AWTEvent
15.1.3.ActionEvent Example with One Button That Demonstrates Sources, Events, and Their ListenersActionEvent Example with One Button That Demonstrates Sources, Events, and Their Listeners
15.1.4.Enabling Other Low-level Events
15.1.5.Event maskEvent mask
15.1.6.Managing Listener Lists with AWTEventMulticasterManaging Listener Lists with AWTEventMulticaster
15.1.7.Semantic Events
15.1.8.Semantic Event Listeners
15.1.9.Managing Listener Lists with EventListenerListManaging Listener Lists with EventListenerList
15.1.10.Writing a Listener as an Anonymous ClassWriting a Listener as an Anonymous Class
15.1.11.Writing a listener as a nested class
15.1.12.Creating a Custom Event
15.1.13.Event object has information about an event, that has happened.
15.1.14.implements AWTEventListener java.awt.AWTEvent.getID()
15.1.16.Event source and listener
15.1.17.Process On Swing Event Thread