//********************************************************************
//  reboundpanel2.java       Author: Pat Moss  Rev. 02 11-11-2005
//
//  Represents the primary panel for the rebound program.
//  Includes Start/Stop animation by clicking the mouse.
//********************************************************************

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

public class reboundpanel2 extends JPanel
{
   private final int WIDTH = 300, HEIGHT = 100;
   private final int DELAY = 20, IMAGE_SIZE = 35;

   private ImageIcon image;
   private Timer timer;
   private String timerstate = "stop"; // Timer state is "stop" or "start"
   private int x, y, moveX, moveY;

   //-----------------------------------------------------------------
   //  Sets up the panel, including the timer for the animation.
   //  And the mouse listener to start/stop the animation.
   //-----------------------------------------------------------------
   public reboundpanel2()
   {
      timer = new Timer(DELAY, new reboundlistener());

      linelistener listener = new linelistener();
      addMouseListener (listener);
      addMouseMotionListener (listener);

      image = new ImageIcon ("happyface.gif");

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

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

   //*****************************************************************
   //  Represents the listener for all mouse events.
   //*****************************************************************
   private class linelistener implements MouseListener,
                                         MouseMotionListener
   {
      //--------------------------------------------------------------
      //  Captures the initial position at which the mouse button is
      //  pressed.
      //--------------------------------------------------------------
      public void mousePressed (MouseEvent event)
      {
        if (timerstate == "stop")
        { timerstate = "start";
          timer.start();
        } else {
          timerstate = "stop";
          timer.stop();
        }
      }

      //--------------------------------------------------------------
      //  Provide empty definitions for unused mouse event methods.
      //--------------------------------------------------------------
      public void mouseClicked (MouseEvent event) {}
      public void mouseReleased (MouseEvent event) {}
      public void mouseEntered (MouseEvent event) {}
      public void mouseExited (MouseEvent event) {}
      public void mouseMoved (MouseEvent event) {}
      public void mouseDragged (MouseEvent event) {}
   }
}