import java.applet.Applet;
import java.awt.Rectangle;
import java.awt.Color;
import java.awt.Graphics;
import java.awt.Graphics2D;
import java.awt.event.MouseListener;
import java.awt.event.MouseEvent;
/** This program will show many squares in an applet.  Each time you click on
 * one, it will turn blue or red, to illustrate taking turns.
 */
public class MouseApplet4 extends Applet
{
  private int [][] board;
  private int howMany;
  private Rectangle [][] box;
  private int row;
  private int col;
  private static final int EMPTY = 0;
  private static final int BLUE = 1;
  private static final int RED = 2;

  public void init()
  {
    board = new int [8][8];
    howMany = 0;

    // When drawing the boundaries of the squares, j refers to the inner
    // loop which is the column number, which corresponds to x.  And so
    // i corresponds to y.  (At first this may seem backwards!)
    box = new Rectangle[8][8];
    for (int i = 0; i < 8; ++i)
      for (int j = 0; j < 8; ++j)
        box[i][j] = new Rectangle(35*j,35*i,35,35);
    DetectInput listener = new DetectInput();
    addMouseListener(listener);
  }

  class DetectInput implements MouseListener
  {
    public void mousePressed(MouseEvent event)
    {
      int x = event.getX();
      int y = event.getY();

      // set row and col based on x and y, and set 7 as their max so we don't
      // go off the board
      row = y / 35;
      col = x / 35;
      if (row > 7)
        row = 7;
      if (col > 7)
        col = 7;

      // Keep track of which box has been clicked.
      // If we take out the check for blank, then we'll be able to steal
      // the opponent's place.
      // We need checks for howMany > 1 to make sure the top left corner
      // isn't already colored in when we start.
      ++howMany;
      if (howMany % 2 == 1 && board[row][col] == EMPTY)
        board[row][col] = BLUE;
      else if (howMany % 2 == 0 && board[row][col] == EMPTY && howMany > 1)
        board[row][col] = RED;
      else if (howMany > 1)
      {
        // We chose a space that's already taken, disregard the fact the we
        // just moved by decrementing howMany.
        --howMany;
      }

      repaint();
    }
    public void mouseReleased(MouseEvent event) {}
    public void mouseClicked(MouseEvent event) {}
    public void mouseEntered(MouseEvent event) {}
    public void mouseExited(MouseEvent event) {}
  }

  public void paint(Graphics g)
  {
    Graphics2D g2 = (Graphics2D) g;
    int i, j;

    // make all boxes (blue or red) that have been clicked
    for (i = 0; i < 8; ++i)
      for (j = 0; j < 8; ++j)
      {
        if (board[i][j] == BLUE)
        {
          g2.setColor(Color.blue);
          g2.fill(box[i][j]);
        }
        else if (board[i][j] == RED && howMany > 1)
        {
          g2.setColor(Color.red);
          g2.fill(box[i][j]);
        }
      }
    // now, draw the board
    for (i = 0; i < 8; ++i)
      for (j = 0; j < 8; ++j)
        g2.draw(box[i][j]);
  }
}