// This example is from the book "Java in a Nutshell, Second Edition".
// Written by David Flanagan.  Copyright (c) 1997 O'Reilly & Associates.
// You may distribute this source code for non-commercial purposes only.
// You may study, modify, and use this example for any purpose, as long as
// this notice is retained.  Note that this example is provided "as is",
// WITHOUT WARRANTY of any kind either expressed or implied.

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

public class Scribble3 extends Applet {
  int last_x, last_y;

  public void init() {
    // Define, instantiate and register a MouseListener object.
    this.addMouseListener(new MouseAdapter() {
      public void mousePressed(MouseEvent e) {
        last_x = e.getX();
        last_y = e.getY();
      }
    });

    // Define, instantiate and register a MouseMotionListener object.
    this.addMouseMotionListener(new MouseMotionAdapter() {
      public void mouseDragged(MouseEvent e) {
        Graphics g = getGraphics();
        int x = e.getX(), y = e.getY();
        g.setColor(Color.black);
        g.drawLine(last_x, last_y, x, y);
        last_x = x; last_y = y;
      }
    });

    // Create a clear button
    Button b = new Button("Clear");
    // Define, instantiate, and register a listener to handle button presses
    b.addActionListener(new ActionListener() {
      public void actionPerformed(ActionEvent e) {  // clear the scribble
        Graphics g = getGraphics();
        g.setColor(getBackground());
        g.fillRect(0, 0, getSize().width, getSize().height);
      }
    });
    // And add the button to the applet
    this.add(b);
  }
}