Handling Events

***********************************    
* ActionExample1.java Inherits from CloseableFrame.java and uses SetSizeButton.java.
    * ActionExample2.java Inherits from CloseableFrame.java.
    **********************************************************
ActionExample1.java
*******************
import java.awt.*;

public class ActionExample1 extends CloseableFrame {
  public static void main(String[] args) {
    new ActionExample1();
  }

  public ActionExample1() {
    super("Handling Events in Component");
    setLayout(new FlowLayout());
    setFont(new Font("Serif", Font.BOLD, 18));
    add(new SetSizeButton(300, 200));
    add(new SetSizeButton(400, 300));
    add(new SetSizeButton(500, 400));
    setSize(400, 300);
    setVisible(true);
  }
}
********************
CloseableFrame.java 
********************
import java.awt.*;
import java.awt.event.*;

/** A Frame that you can actually quit. Used as the starting 
 *  point for most Java 1.1 graphical applications.
 ***********************

public class CloseableFrame extends Frame {
  public CloseableFrame(String title) {
    super(title);
    enableEvents(AWTEvent.WINDOW_EVENT_MASK);
  }

  /** Since we are doing something permanent, we need
   *  to call super.processWindowEvent first.
   */
  
  public void processWindowEvent(WindowEvent event) {
    super.processWindowEvent(event); // Handle listeners.
    if (event.getID() == WindowEvent.WINDOW_CLOSING) {
      // If the frame is used in an applet, use dispose().
      System.exit(0);
    }
  }
}
**********************
SetSizeButton.java
**********************
import java.awt.*;
import java.awt.event.*;

///////////////////////
public class SetSizeButton extends Button 
                           implements ActionListener {
  private int width, height;

  public SetSizeButton(int width, int height) {
    super("Resize to " + width + "x" + height);
    this.width = width;
    this.height = height;
    addActionListener(this);
  }

  public void actionPerformed(ActionEvent event) {
    getParent().setSize(width, height);
    getParent().invalidate();
    getParent().validate();
  }
}
***********************
ActionExample2.java
***********************
import java.awt.*;
import java.awt.event.*;

/***********/
public class ActionExample2 extends CloseableFrame
                            implements ActionListener {
  public static void main(String[] args) {
    new ActionExample2();
  }

  private Button button1, button2, button3;

  public ActionExample2() {
    super("Handling Events in Other Object");
    setLayout(new FlowLayout());
    setFont(new Font("Serif", Font.BOLD, 18));
    button1 = new Button("Resize to 300x200");
    button2 = new Button("Resize to 400x300");
    button3 = new Button("Resize to 500x400");
    button1.addActionListener(this);
    button2.addActionListener(this);
    button3.addActionListener(this);
    add(button1);
    add(button2);
    add(button3);
    setSize(400, 300);
    setVisible(true);
  }

  public void actionPerformed(ActionEvent event) {
    if (event.getSource() == button1) {
      updateLayout(300, 200);
    } else if (event.getSource() == button2) {
      updateLayout(400, 300);
    } else if (event.getSource() == button3) {
      updateLayout(500, 400);
    }
  }
  
  private void updateLayout(int width, int height) {
    setSize(width, height);
    invalidate();
    validate();
  }
}
****************/>
CloseableFrame.java.
****************/><
import java.awt.*;
import java.awt.event.*;

/** A Frame that you can actually quit. Used as the starting 
 *  point for most Java 1.1 graphical applications.
 *
 *********************

public class CloseableFrame extends Frame {
  public CloseableFrame(String title) {
    super(title);
    enableEvents(AWTEvent.WINDOW_EVENT_MASK);
  }

  /** Since we are doing something permanent, we need
   *  to call super.processWindowEvent first.
   */
  
  public void processWindowEvent(WindowEvent event) {
    super.processWindowEvent(event); // Handle listeners.
    if (event.getID() == WindowEvent.WINDOW_CLOSING) {
      // If the frame is used in an applet, use dispose().
      System.exit(0);
    }
  }
}
***************