**
  * @author  insert your name here
  * @version   S2, 2006
*/
import java.awt.*;
public class Snake {
 private static final int MAX_BODY_PARTS = 1000;
 private int direction;
 private int left, top;
 private Rectangle[] rects ;
 private int numberOfParts;
 public Snake () {
  left = SnakeConstants.SNAKE_START_X;
  top = SnakeConstants.SNAKE_START_Y;
  direction = SnakeConstants.SNAKE_RIGHT;
  rects = new Rectangle[1000];
  rects[0] = new Rectangle( SnakeConstants.SNAKE_START_RECT );
  numberOfParts = 1;
 }
 public void add(){
  numberOfParts++;
 }
 public void drawSnake( Graphics g ) {
  g.setColor( Color.RED );
  g.fillRect( left, top, SnakeConstants.SIZE, SnakeConstants.SIZE );
  Rectangle r;
  for (int i=0; i<numberOfParts; i++ ) {
   r = rects[i];
   g.setColor( Color. GREEN);
   g.fillRect( r.x, r.y, r.width, r.height );
  }
 }
 public void move() {
  int previousX = left;
  int previousY = top;
  int leftSnake = rects[numberOfParts-1].x;
  int topSnake = rects[numberOfParts-1].y;
  if ( direction == SnakeConstants.SNAKE_UP ) {
   top = top - SnakeConstants.SIZE;
  } else if ( direction == SnakeConstants.SNAKE_DOWN ) {
   top = top + SnakeConstants.SIZE;
  } else if ( direction == SnakeConstants.SNAKE_RIGHT ) {
   left = left + SnakeConstants.SIZE;
  } else if ( direction == SnakeConstants.SNAKE_LEFT ) {
   left = left - SnakeConstants.SIZE;
  }
  rects[numberOfParts] = new Rectangle( leftSnake, topSnake, SnakeConstants.SIZE, SnakeConstants.SIZE );
  if ( intersectsBoundary() ) {
   left = previousX;
   top = previousY;
  }
 }
 public void setDirection( int dir ) {
  direction = dir;
 }
 public boolean intersectsBoundary() {
  Rectangle snakeR = new Rectangle( left, top, SnakeConstants.SIZE, SnakeConstants.SIZE );
  return  snakeR.intersects( SnakeConstants.NORTH_BOUNDARY )|| snakeR.intersects( SnakeConstants.SOUTH_BOUNDARY )|| snakeR.intersects( SnakeConstants.WEST_BOUNDARY )|| snakeR.intersects( SnakeConstants.EAST_BOUNDARY ) ;
 }
}

/**
  *
  * @author  Adriana Ferraro
  * @version   S2, 2006
*/
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class SnakeJPanel extends JPanel implements ActionListener, MouseListener, KeyListener {
 private Timer t;
 private Snake snake;
 private YumYum yumyum;
 public SnakeJPanel() {
  t = new Timer( 200, this );
  snake = new Snake();
  yumyum = new YumYum();
  addKeyListener( this );
  addMouseListener( this );
 }
//-------------------------------------------------------------------
//-------- Move the Snake object and, after the move, ---------------
//-------- check that it has not collided with the  -----------------
//-------- NoNos.  Also check if the snake --------------------------
//-------- has eaten the YumYum object ------------------------------
//-------------------------------------------------------------------
  public void actionPerformed( ActionEvent e ) {
  snake.move();
  repaint();
  }
//-------------------------------------------------------------------
//-------- Draw all the Snake game objects. -------------------------
//-------------------------------------------------------------------
 public void paintComponent( Graphics g ) {
  super.paintComponent( g );
  Rectangle gameArea = SnakeConstants.GAME_AREA;
 
 
 
  g.setColor(Color.WHITE);
  g.fillRect( gameArea.x, gameArea.y, gameArea.width, gameArea.height );
  drawGrid(g);
  snake.drawSnake(g);
  yumyum.drawYum(g);
 }
//-------------------------------------------------------------------
//-------- Draw a grid which helps to check that --------------------
//-------- the snake game objects are lined up.  --------------------
//-------------------------------------------------------------------
 private void drawGrid(Graphics g ) {
  int jump = SnakeConstants.SIZE;
  int x = SnakeConstants.TOP_LEFT.x;
  int y = SnakeConstants.TOP_LEFT.y;
  int endX = SnakeConstants.TOP_RIGHT.x;
  int endY = SnakeConstants.TOP_RIGHT.y + SnakeConstants.HEIGHT;
  for( ; x<=endX; ) {
   g.setColor(Color.LIGHT_GRAY);
   g.drawLine( x, y, x, endY );
   if ( x == 0 || x==endX ) {
    g.setColor(Color.BLACK);
    g.drawLine( x, y, x, endY );
   }
   x = x + jump;
  }
  x = SnakeConstants.TOP_LEFT.x;
  for( ; y<=endY; ) {
   g.setColor(Color.LIGHT_GRAY);
   g.drawLine( x, y, endX, y );
   if ( y == 0 || y==endY ) {
    g.setColor(Color.BLACK);
    g.drawLine( x, y, endX, y );
   }
   y = y + jump;
  }
 }
//-------------------------------------------------------------------
//-------- When a key is pressed the snake starts. ------------------
//-------- The arrow keys change the direction of the ---------------
//-------- Snake object. --------------------------------------------
//-------------------------------------------------------------------
 public void keyPressed( KeyEvent e ) {
  t.start();
  int code = e.getKeyCode();
  if ( code == KeyEvent.VK_UP ) {
   snake.setDirection( SnakeConstants.SNAKE_UP );
  } else if (  code == KeyEvent.VK_DOWN ) {
   snake.setDirection( SnakeConstants.SNAKE_DOWN );
  } else if (  code == KeyEvent.VK_LEFT) {
   snake.setDirection( SnakeConstants.SNAKE_LEFT );
  } else if (  code == KeyEvent.VK_RIGHT ) {
   snake.setDirection( SnakeConstants.SNAKE_RIGHT );
  }
 }
 public void keyReleased( KeyEvent newEvent ) { }
 public void keyTyped( KeyEvent newEvent ) { }
   public void mousePressed( MouseEvent newEvent ) {
  requestFocusInWindow();
   }
    public void mouseReleased( MouseEvent newEvent ) { }
    public void mouseClicked( MouseEvent newEvent ) { }
    public void mouseEntered( MouseEvent newEvent ) { }
    public void mouseExited( MouseEvent newEvent ) { }
}
/*
*/