Computer Science 523
Advanced Programming
Summer 2014, The College of Saint Rose
TicTacToe Demo
A working demo of TicTacToe will appear below. Click inside the applet to interact with it.
TicTacToe BlueJ Project
Click here to download a BlueJ project for TicTacToe.
TicTacToe Source Code
The Java source code for TicTacToe is below. Click on a file name to download it.
/*
* Example TicTacToe: A Java Swing implementation of a Tic-Tac-Toe game
*
* Jim Teresco, The College of Saint Rose, CSC 523, Summer 2014
*
* Based on Objectdraw version, also by Jim Teresco
*
* $Id: TicTacToe.java 2383 2014-06-18 19:49:50Z terescoj $
*/
import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Container;
import java.awt.Font;
import java.awt.GridLayout;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.JApplet;
import javax.swing.JButton;
import javax.swing.JLabel;
import javax.swing.JPanel;
public class TicTacToe extends JApplet implements ActionListener {
// some constants to define parameters of the game
private static final int GAME_SIZE = 3;
private static final Color BUTTON_COLOR = Color.yellow;
// Denote value of a square to show who has played there
private static final int EMPTY = 0;
private static final int X_MARK = 1;
private static final int O_MARK = 2;
// The grid contents: int values that will contain the int
// values above, and the actual JButton objects we will
// use for game play
private int[][] marks;
private JButton[][] buttons;
// Whose turn it is next
private int nextMark = X_MARK;
// Whether the game has been won or not
private boolean gameOver = false;
// the label that will give game status
private JLabel messageLabel;
// the play again button
private JButton playAgain;
public void init() {
Container contentPane = getContentPane();
// create our int representation of the game status
marks = new int[GAME_SIZE][GAME_SIZE];
// we start with a panel at the top for a message
JPanel topPanel = new JPanel();
messageLabel = new JLabel("");
messageLabel.setFont(new Font("Serif", Font.BOLD, 36));
topPanel.add(messageLabel);
contentPane.add(topPanel, BorderLayout.NORTH);
// the grid for game play
buttons = new JButton[GAME_SIZE][GAME_SIZE];
JPanel gamePanel = new JPanel();
gamePanel.setLayout(new GridLayout(GAME_SIZE, GAME_SIZE));
for (int row = 0; row < GAME_SIZE; row++) {
for (int col = 0; col < GAME_SIZE; col++) {
buttons[row][col] = new JButton("X");
buttons[row][col].addActionListener(this);
buttons[row][col].setFont(new Font("Sans Serif", Font.BOLD, 72));
buttons[row][col].addActionListener(this);
buttons[row][col].setBackground(Color.black);
buttons[row][col].setOpaque(true);
gamePanel.add(buttons[row][col]);
}
}
contentPane.add(gamePanel, BorderLayout.CENTER);
// and a button at the bottom for restarting the game
JPanel bottomPanel = new JPanel();
playAgain = new JButton("Play Again");
playAgain.addActionListener(this);
bottomPanel.add(playAgain);
contentPane.add(bottomPanel, BorderLayout.SOUTH);
contentPane.validate();
reset(); // initialize game play
}
// everything that needs to happen for the start of a new game
private void reset() {
for (int row = 0; row < GAME_SIZE; row++) {
for (int col = 0; col < GAME_SIZE; col++) {
buttons[row][col].setText("");
marks[row][col] = EMPTY;
}
}
gameOver = false;
messageLabel.setText("Welcome! X goes first!");
nextMark = X_MARK;
playAgain.setEnabled(false);
}
/**
* Check to see if the game is won as a result of a mark being placed
* at position row, col. The game is over if an entire row, column, or
* diagonal has the same pieces.
*
* @param row the row number (0, 1, 2) of the cell just marked
* @param col the column number (0, 1, 2) of the cell just marked
* @param matchMark the mark, X_MARK or O_MARK, just placed
*
* @return true if the current player now has won the game, false otherwise
*/
private boolean checkGameWon(int row, int col, int matchMark) {
return checkForRowWin(row, matchMark)
|| checkForColWin(col, matchMark)
|| checkForDiagWin(matchMark)
|| checkForDiag2Win(matchMark);
}
/**
* Check to see if the game is a tie: all positions are occupied,
* but no one has won.
*
* @return true if all positions are occupied
*/
private boolean checkAllFilled() {
for (int row = 0; row < GAME_SIZE; row++) {
for (int col = 0; col < GAME_SIZE; col++) {
if (marks[row][col] == EMPTY) {
return false;
}
}
}
return true;
}
/**
* Check for a win in the given row by the player with the
* given mark.
*
* @param row the row number to check
* @param matchMark the mark, X_MARK or O_MARK, just placed
*
* @return whether the given row contains all matchMark entries
*/
private boolean checkForRowWin(int row, int matchMark) {
for (int col = 0; col < GAME_SIZE; ++col) {
if (marks[row][col] != matchMark) {
return false;
}
}
return true;
}
/**
* Check for a win in the given column by the player with the
* given mark.
*
* @param col the column number to check
* @param matchMark the mark, X_MARK or O_MARK, just placed
*
* @return whether the given column contains all matchMark entries
*/
private boolean checkForColWin(int col, int matchMark) {
for (int row=0; row < GAME_SIZE; ++row) {
if (marks[row][col] != matchMark) {
return false;
}
}
return true;
}
/**
* Check for a win in the main diagonal by the player with the
* given mark. This is the diagonal from the top left to bottom right.
*
* @param matchMark the mark, X_MARK or O_MARK, just placed
*
* @return whether the main diagonal contains all matchMark entries
*/
private boolean checkForDiagWin(int matchMark) {
for (int i = 0; i < GAME_SIZE; ++i) {
if (marks[i][i] != matchMark) {
return false;
}
}
return true;
}
/**
* Check for a win in the off diagonal by the player with the
* given mark. This is the diagonal from the bottom left to top right.
*
* @param matchMark the mark, X_MARK or O_MARK, just placed
*
* @return whether the off diagonal contains all matchMark entries
*/
private boolean checkForDiag2Win(int matchMark) {
for (int i = 0; i < GAME_SIZE; ++i) {
if (marks[i][GAME_SIZE-i-1] != matchMark) {
return false;
}
}
return true;
}
/**
* Draw the appropriate mark in the appropriate row/col in
* the Tic-Tac-Toe board
*
* @param row the row number (0, 1, 2) of the cell to mark
* @param col the column number (0, 1, 2) of the cell to mark
* @param mark what to mark, X_MARK or O_MARK
*/
private void drawMark(int row, int col, int mark) {
if (mark == X_MARK) {
buttons[row][col].setText("X");
} else {
buttons[row][col].setText("O");
}
}
public void actionPerformed(ActionEvent eventInfo) {
if (eventInfo.getSource() == playAgain) {
// this can only happen if the button is enabled, so
// we reset unconditionally here
reset();
}
else {
// Figure out which cell in the grid was clicked in
int col = 0;
int row = 0;
for (int r = 0; r < GAME_SIZE; r++) {
for (int c = 0; c < GAME_SIZE; c++) {
if (eventInfo.getSource() == buttons[r][c]) {
col = c;
row = r;
}
}
}
// Make sure the grid is empty before adding a mark.
// Also make sure the game is not already over
if (marks[row][col] == EMPTY && !gameOver) {
// Add the mark
marks[row][col] = nextMark;
drawMark(row, col, nextMark);
// See if the game is won
if (checkGameWon(row, col, nextMark)) {
if (nextMark == X_MARK) {
messageLabel.setText("X Wins!");
} else {
messageLabel.setText("O Wins!");
}
gameOver = true;
}
// see if it's a tie
if (!gameOver && checkAllFilled()) {
messageLabel.setText("It's a tie!");
gameOver = true;
}
if (!gameOver) {
// switch players
if (nextMark == X_MARK) {
nextMark = O_MARK;
messageLabel.setText("O's Turn");
} else {
nextMark = X_MARK;
messageLabel.setText("X's Turn");
}
}
else {
// if the game is over, we enable the play again button
playAgain.setEnabled(true);
}
}
}
}
}