// Make it easy to access classes and methods of selected packages.

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

/**
 * This class subclasses Applet to define an applet for a virtual die. It
 * implements the ActionListener interface to respond to action events
 * for the die (which is a Button extension).
 *
 * Written by: Jon Huhtala
 */

public class App extends Applet implements ActionListener {

  // Instance variables for referencing the die.

  private Die die;

  // This method defines initial (one-time) applet processing.

  public void init() {

    // Specify that a border layout is to be used.

    setSize(100, 105);
    setLayout(new BorderLayout());

    // Instantiate a blue die, register its listener, and add it to the
    // center of the applet frame.

    die = new Die(Color.blue);
    die.addActionListener(this);
    add(die, BorderLayout.CENTER);
  }

  // This implements the abstract event handler method of the ActionListener
  // interface to handle ActionEvents (button clicks). When the user clicks
  // the die, it constitutes a roll of the die.

  public void actionPerformed(ActionEvent e) {
    die.roll();
  }
}

 // This class subclasses Button to encapsulate the processing and
 // displaying of a single die having Button characteristics.

class Die extends Button {

  // Instance variables for holding the die's value and color.

  private byte dieValue;
  private Color dieColor;

  // This constructor instantiates a die object in the specified color.

  public Die(Color initColor) {

    // Call the superclass (Button) constructor, set the die color, and
    // give the die its first roll.

    super("");
    dieColor = initColor;
    roll();
  }

  // This method simulates rolling the die.

  public void roll() {

    // Randomly determine a new value for the die and redraw it.

    dieValue = randomValue();
    repaint();
  }

  // This method may be called to change the color of the die.

  public void setColor(Color newColor) {
    dieColor = newColor;
  }

  // This method may be called to get the color of the die.

  public Color getColor() {
    return dieColor;
  }

  // This method may be called to get the current value of the die.

  public byte getValue() {
    return dieValue;
  }

  // This method can ONLY be called from within this class. It returns a
  // random number from 1 to 6 to simulate rolling the die.

  private byte randomValue() {

    // Calling the random() method of the Math class returns a real number
    // greater than zero and less than one. Multiplying by 1000 and taking
    // the remainder from division by six produces a random integer from
    // zero to five. Adding one results in the desired value but a cast is
    // needed to convert it to a byte.

    return (byte) (((1000 * Math.random()) % 6) + 1);
  }

  // This method is automatically called whenever the die needs to be
  // rendered. It receives a Graphics object (its context) as a parameter.

  public void paint(Graphics g) {

    // Determine the size of the die.

    Dimension dieSize = this.getSize();

    // Draw the blank die.

    g.setColor(dieColor);
    g.fill3DRect(0, 0, dieSize.width, dieSize.height, true);

    // Set the spot color.

    g.setColor(Color.white);

    // Calculate the spot size. This makes the spots "scaleable".

    int spotHeight = dieSize.height / 12;
    int spotWidth = dieSize.width / 12;

    // Draw the spots based upon the die's value.

    switch(dieValue) {

      // Draw the spot pattern for a one.

      case 1:
        g.fillOval((dieSize.width/2)-spotWidth, (dieSize.height/2)-spotHeight, spotWidth*2, spotHeight*2);
        break;

      // Draw the spot pattern for a two.

      case 2:
        g.fillOval((dieSize.width/4)-spotWidth, (dieSize.height/4)-spotHeight, spotWidth*2, spotHeight*2);
        g.fillOval(((dieSize.width/4)*3)-spotWidth, ((dieSize.height/4)*3)-spotHeight, spotWidth*2, spotHeight*2);
        break;

      // Draw the spot pattern for a three.

      case 3:
        g.fillOval((dieSize.width/4)-spotWidth, (dieSize.height/4)-spotHeight, spotWidth*2, spotHeight*2);
        g.fillOval((dieSize.width/2)-spotWidth, (dieSize.height/2)-spotHeight, spotWidth*2, spotHeight*2);
        g.fillOval(((dieSize.width/4)*3)-spotWidth, ((dieSize.height/4)*3)-spotHeight, spotWidth*2, spotHeight*2);
        break;

      // Draw the spot pattern for a four.

      case 4:
        g.fillOval((dieSize.width/4)-spotWidth, (dieSize.height/4)-spotHeight, spotWidth*2, spotHeight*2);
        g.fillOval(((dieSize.width/4)*3)-spotWidth, (dieSize.height/4)-spotHeight, spotWidth*2, spotHeight*2);
        g.fillOval((dieSize.width/4)-spotWidth, ((dieSize.height/4)*3)-spotHeight, spotWidth*2, spotHeight*2);
        g.fillOval(((dieSize.width/4)*3)-spotWidth, ((dieSize.height/4)*3)-spotHeight, spotWidth*2, spotHeight*2);
        break;

      // Draw the spot pattern for a five.

      case 5:
        g.fillOval((dieSize.width/4)-spotWidth, (dieSize.height/4)-spotHeight, spotWidth*2, spotHeight*2);
        g.fillOval(((dieSize.width/4)*3)-spotWidth, (dieSize.height/4)-spotHeight, spotWidth*2, spotHeight*2);
        g.fillOval((dieSize.width/2)-spotWidth, (dieSize.height/2)-spotHeight, spotWidth*2, spotHeight*2);
        g.fillOval((dieSize.width/4)-spotWidth, ((dieSize.height/4)*3)-spotHeight, spotWidth*2, spotHeight*2);
        g.fillOval(((dieSize.width/4)*3)-spotWidth, ((dieSize.height/4)*3)-spotHeight, spotWidth*2, spotHeight*2);
        break;

      // Draw the spot pattern for a six.

      case 6:
        g.fillOval((dieSize.width/4)-spotWidth, (dieSize.height/4)-spotHeight, spotWidth*2, spotHeight*2);
        g.fillOval(((dieSize.width/4)*3)-spotWidth, (dieSize.height/4)-spotHeight, spotWidth*2, spotHeight*2);
        g.fillOval((dieSize.width/4)-spotWidth, (dieSize.height/2)-spotHeight, spotWidth*2, spotHeight*2);
        g.fillOval(((dieSize.width/4)*3)-spotWidth, (dieSize.height/2)-spotHeight, spotWidth*2, spotHeight*2);
        g.fillOval((dieSize.width/4)-spotWidth, ((dieSize.height/4)*3)-spotHeight, spotWidth*2, spotHeight*2);
        g.fillOval(((dieSize.width/4)*3)-spotWidth, ((dieSize.height/4)*3)-spotHeight, spotWidth*2, spotHeight*2);
        break;
    }
  }
}