/*
 *  ======================================================================
 *  File : SimpleDraw.java -- This applet let you draw with the mouse.
 * 
 *  Written By : David Chancogne                            September 1997
 *  ======================================================================
 */

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

public class SimpleDraw extends Applet {

      int last_x;                 // Last position of the mouse.
      int last_y;                 // Last position of the mouse.
      private Button clearButton; // This is the "Clear" Button.

      public void init() {
         
          // Set the background color.

          this.setBackground(Color.white); 

          // Create and add 'Clear' button to applet.

          clearButton = new Button("Clear");
          this.add(clearButton);             

          // Add the 3 mouse listeners.

          clearButton.addMouseListener(new ClearButtonListener(this));
          this.addMouseListener(new MousePressedListener(this));
          this.addMouseMotionListener(new MouseDraggedListener(this));

      } // End of method init
}       // End of class SimpleDraw

class MousePressedListener extends MouseAdapter {

      SimpleDraw applet; // The calling applet

      public MousePressedListener(SimpleDraw a) {
          applet= a;
      }

      public void mousePressed(MouseEvent e) {

          applet.last_x = e.getX();
          applet.last_y = e.getY();

      } // End of method mousePressed
}       // End of class MousePressedListener

class MouseDraggedListener extends MouseMotionAdapter {

      SimpleDraw applet; // The calling applet.

      public MouseDraggedListener(SimpleDraw a) {
          applet =a;
      }

      public void mouseDragged(MouseEvent e) {

          // Call the applet drawing method.

          Graphics g = applet.getGraphics();
          g.drawLine(applet.last_x, applet.last_y, e.getX(), e.getY());
          applet.last_x = e.getX();
          applet.last_y = e.getY();

      } // End of method mouseDragged
}       // End of class MouseDraggedListener

class ClearButtonListener extends MouseAdapter {

      SimpleDraw applet; // The calling applet.

      public ClearButtonListener(SimpleDraw a) {
          applet = a;
      } // End of constructor method

      public void mouseReleased(MouseEvent e) {

          // Get the graphic context

          Graphics g = applet.getGraphics();  

          // Draw a rectangle with the same color as the background

          g.setColor(applet.getBackground());
          Dimension r = applet.getSize();
          g.fillRect(0, 0, r.width, r.height);

      } // End of method mouseReleased
}       // End of class ClearButtonListener