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

1. Java Tutorial
2. Swing Event
3. Event

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() {
    setBackground(Color.CYAN);
    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);
          actionListenerList.actionPerformed(actionEvent);
        }
      }
    };
    MouseListener internalMouseListener = new MouseAdapter() {
      public void mousePressed(MouseEvent mouseEvent) {
        requestFocusInWindow();
      }
    };
    addKeyListener(internalKeyListener);
    addMouseListener(internalMouseListener);
  }
  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");
    frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    KeyTextComponent keyTextComponent = new KeyTextComponent();
    final JTextField textField = new JTextField();
    ActionListener actionListener = new ActionListener() {
      public void actionPerformed(ActionEvent actionEvent) {
        String keyText = actionEvent.getActionCommand();
        textField.setText(keyText);
      }
    };
    keyTextComponent.addActionListener(actionListener);
    frame.add(keyTextComponent, BorderLayout.CENTER);
    textField.setText("Press keyboard after clicking the above blank area");
    frame.add(textField, BorderLayout.SOUTH);
    frame.setSize(300, 200);
    frame.setVisible(true);
  }
}

15.1.Event
	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 Listeners
	15.1.4.	Enabling Other Low-level Events
	15.1.5.	Event mask
	15.1.6.	Managing Listener Lists with AWTEventMulticaster
	15.1.7.	Semantic Events
	15.1.8.	Semantic Event Listeners
	15.1.9.	Managing Listener Lists with EventListenerList
	15.1.10.	Writing 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
	15.1.15.	int java.awt.AWTEvent.getID()
	15.1.16.	Event source and listener
	15.1.17.	Process On Swing Event Thread