/** Adapted from Java in a Nutshell
 **/

import java.applet.Applet;
import java.awt.Button;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.ActionListener;
import java.awt.event.ActionEvent;
import java.awt.event.MouseListener;
import java.awt.event.MouseMotionListener;
import java.awt.event.MouseEvent;

public class ScribbleApplet extends Applet 
  implements ActionListener, MouseListener, MouseMotionListener {

  private int last_x, last_y;

  public void init() {
    addMouseListener(this);
    addMouseMotionListener(this);

    // Create a clear button
    Button b = new Button("Clear");

    // Tell the button which object (this applet) has the
    // actionPerformed() method to call when button is clicked.
    b.addActionListener(this);
    add(b);
  }

  /** From ActionListener interface: clear the applet area when
   ** button is pressed
   **/
  public void actionPerformed( ActionEvent e) {
    Graphics g = getGraphics();
    g.setColor(getBackground());
    Dimension d = getSize();
    g.fillRect(0, 0, d.width, d.height);
  }

  /** From MouseListener interface: remember where mouse was ehen
   ** mouse button is pressed.
   **/
  public void mousePressed( MouseEvent e) {
    last_x = e.getX();
    last_y = e.getY();
  }

  /** From MouseMotionListener interface: determine where mouse is
   ** while button is down; draw a line from last position to this
   ** one, remember where mouse is fo next time.
   **/
  public void mouseDragged(MouseEvent e) {
    Graphics g = getGraphics();
    int x = e.getX();
    int y = e.getY();
    g.drawLine(last_x, last_y, x, y);
    last_x = x;
    last_y = y;
  }

  /** Both MouseListener and MouseMotionListener interfaces define
   ** other methods that must be implemented.  These do nothing
   ** implementations satisfy the MouseListener interface
   ** "contract".
   **/
  public void mouseReleased(MouseEvent e) {
  }
  public void mouseClicked(MouseEvent e) {
  }
  public void mouseEntered(MouseEvent e) {
  }
  public void mouseExited(MouseEvent e) {
  }
  /** And this do nothing implementation satisfies the
   ** MouseMotionListener interface "contract".
   **/
  public void mouseMoved(MouseEvent e) {
  }

  }