//******************************************************************** // Reboun

Question

//********************************************************************
// Rebound.java
// Demonstrates an animation and the use of the Timer class.
//********************************************************************

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class Rebound
{
   //-----------------------------------------------------------------
   // Displays the main frame of the program.
   //-----------------------------------------------------------------
   public static void main (String[] args)
   {
      JFrame frame = new JFrame ("Rebound");
      frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);

      frame.getContentPane().add(new ReboundPanel());
      frame.pack();
      frame.setVisible(true);
   }
}

//********************************************************************
// ReboundPanel.java   
// Represents the primary panel for the Rebound program.
//********************************************************************

import java.awt.*;
import java.awt.event.*;

import javax.swing.*;

public class ReboundPanel extends JPanel
{
   private static final long serialVersionUID = 1L;
   private final int WIDTH = 300, HEIGHT = 100;
   private final int DELAY = 20, IMAGE_SIZE = 35;

   private ImageIcon image;
   private Timer timer;
   private int x, y, moveX, moveY;

   //-----------------------------------------------------------------
   // Sets up the panel, including the timer for the animation.
   //-----------------------------------------------------------------
   public ReboundPanel()
   {
      timer = new Timer(DELAY, new ReboundListener());

      image = new ImageIcon (getClass().getResource("happyFace.gif"));

      x = 0;
      y = 40;
      moveX = moveY = 3;

      setPreferredSize (new Dimension(WIDTH, HEIGHT));
      setBackground (Color.black);
      timer.start();
   }

   //-----------------------------------------------------------------
   // Draws the image in the current location.
   //-----------------------------------------------------------------
   public void paintComponent (Graphics page)
   {
      super.paintComponent (page);
      image.paintIcon (this, page, x, y);
   }

   //*****************************************************************
   // Represents the action listener for the timer.
   //*****************************************************************
   private class ReboundListener implements ActionListener
   {
      //--------------------------------------------------------------
      // Updates the position of the image and possibly the direction
      // of movement whenever the timer fires an action event.
      //--------------------------------------------------------------
      public void actionPerformed (ActionEvent event)
      {
         x += moveX;
         y += moveY;

         if (x <= 0 || x >= WIDTH-IMAGE_SIZE)
            moveX = moveX * -1;

         if (y <= 0 || y >= HEIGHT-IMAGE_SIZE)
            moveY = moveY * -1;
  
         repaint();
      }
   }
   class MousePressListener implements MouseListener
   {
       public void mousePressed(MouseEvent event)
       {
           if(event.getX() <= 30 && event.getY() <= 30)
           {
               if(event.getX() <= 30 && event.getY() <= 30)
               {
                   image = new ImageIcon(getClass().getResource("redSmiley.gif"));
               }
               else
                   image = new ImageIcon(getClass().getResource("happyFace.gif"));
           }
       }
       public void mouseClicked(MouseEvent event)
       {
           if(event.getX() <= 30 && event.getY() <= 30)
           {
               image = new ImageIcon(getClass().getResource("redSmiley.gif"));
           }
           else
               image = new ImageIcon(getClass().getResource("happyFace.gif"));
       }
       //Empty methods
       public void mouseEntered(MouseEvent arg0)
       {  
       }
       public void mouseExited(MouseEvent arg0)
       {  
       }
       public void mouseReleased(MouseEvent arg0)
       {
       }
   }
}

I need the two images at the top to switch between each other when the mouse is clicked within 30 pixels of the image. I need help getting the button click to be registered and to switch the images whenever they are clicked.

Explanation / Answer

/** * Rebound.java * * Demonstrates an animation and the use of the Timer class. * @author Lewis and Loftus. Converted to JApplet by Scot Drysdale */ import javax.swing.*; import java.awt.*; import java.awt.event.*; public class Rebound extends JApplet { private static final long serialVersionUID = 1L; private final int APPLET_WIDTH = 200; private final int APPLET_HEIGHT = 100; private final int IMAGE_SIZE = 35; private final int DELAY = 20; private Timer timer; // Timer object to get regular callbacks private Image image; // Image of thing to be drawn private int x, y, moveX, moveY; // /** * Sets up the applet, including the timer for the animation. */ public void init() { addMouseListener(new ReboundMouseListener()); Container cp = getContentPane(); // Content pane holds components cp.add(new Canvas()); // The canvas is the only component x = 0; y = 40; moveX = moveY = 3; image = getImage(getCodeBase(), "happyFace.gif"); setBackground(Color.black); setSize(APPLET_WIDTH, APPLET_HEIGHT); timer = new Timer(DELAY, new ReboundActionListener()); timer.start(); setVisible(true); // Makes the applet (and its components) visible } private class Canvas extends JPanel { private static final long serialVersionUID = 1L; /** * Draws the image in the current location. * @param page the graphics object to draw on. */ public void paintComponent(Graphics page) { super.paintComponent(page); page.drawImage(image, x, y, this); } } /** * Represents the mouse listener for the applet. */ private class ReboundMouseListener implements MouseListener { /** * Stops or starts the timer (and therefore the animation) * when the mouse button is clicked. * @param event the event that caused this callback */ public void mouseClicked(MouseEvent event) { if (timer.isRunning()) timer.stop(); else timer.start(); } //-------------------------------------------------------------- // Provide empty definitions for unused event methods. //-------------------------------------------------------------- public void mouseEntered(MouseEvent event) {} public void mouseExited(MouseEvent event) {} public void mousePressed(MouseEvent event) {} public void mouseReleased(MouseEvent event) {} } /** * Represents the action listener for the timer. */ private class ReboundActionListener implements ActionListener { /** * Updates the position of the image and possibly the direction * of movement whenever the timer fires an action event. * @param event the event that caused this callback */ public void actionPerformed(ActionEvent event) { x += moveX; y += moveY; if (x = APPLET_WIDTH - IMAGE_SIZE) moveX = moveX * -1; if (y = APPLET_HEIGHT - IMAGE_SIZE) moveY = moveY * -1; repaint(); } } }

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