Java tutorial
File:test.htm<title>TicTacToe</title><hr><applet code=TicTacToe.class width=120 height=120>
</applet>
File: TicTacToe.java
/*
* @(#)TicTacToe.java 1.2 95/10/13
*
* Copyright (c) 1994-1996 Sun Microsystems, Inc. All Rights Reserved.
*
* Permission to use, copy, modify, and distribute this software
* and its documentation for NON-COMMERCIAL or COMMERCIAL purposes and
* without fee is hereby granted.
* Please refer to the file http://java.sun.com/copy_trademarks.html
* for further important copyright and trademark information and to
* http://java.sun.com/licensing.html for further important licensing
* information for the Java (tm) Technology.
*
* SUN MAKES NO REPRESENTATIONS OR WARRANTIES ABOUT THE SUITABILITY OF
* THE SOFTWARE, EITHER EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED
* TO THE IMPLIED WARRANTIES OF MERCHANTABILITY, FITNESS FOR A
* PARTICULAR PURPOSE, OR NON-INFRINGEMENT. SUN SHALL NOT BE LIABLE FOR
* ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
* DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES.
*
* THIS SOFTWARE IS NOT DESIGNED OR INTENDED FOR USE OR RESALE AS ON-LINE
* CONTROL EQUIPMENT IN HAZARDOUS ENVIRONMENTS REQUIRING FAIL-SAFE
* PERFORMANCE, SUCH AS IN THE OPERATION OF NUCLEAR FACILITIES, AIRCRAFT
* NAVIGATION OR COMMUNICATION SYSTEMS, AIR TRAFFIC CONTROL, DIRECT LIFE
* SUPPORT MACHINES, OR WEAPONS SYSTEMS, IN WHICH THE FAILURE OF THE
* SOFTWARE COULD LEAD DIRECTLY TO DEATH, PERSONAL INJURY, OR SEVERE
* PHYSICAL OR ENVIRONMENTAL DAMAGE ("HIGH RISK ACTIVITIES"). SUN
* SPECIFICALLY DISCLAIMS ANY EXPRESS OR IMPLIED WARRANTY OF FITNESS FOR
* HIGH RISK ACTIVITIES.
*/
import java.awt.*;
import java.awt.image.*;
import java.net.*;
import java.applet.*;
/**
* A TicTacToe applet. A very simple, and mostly brain-dead
* implementation of your favorite game!
*
* In this game a position is represented by a white and black
* bitmask. A bit is set if a position is ocupied. There are
* 9 squares so there are 1<<9 possible positions for each
* side. An array of 1<<9 booleans is created, it marks
* all the winning positions.
*
* @version 1.2, 13 Oct 1995
* @author Arthur van Hoff
* @modified 96/04/23 Jim Hagen : winning sounds
*/
public class TicTacToe extends Applet {
/**
* White's current position. The computer is white.
*/
int white;
/**
* Black's current position. The user is black.
*/
int black;
/**
* The squares in order of importance...
*/
final static int moves[] = { 4, 0, 2, 6, 8, 1, 3, 5, 7 };
/**
* The winning positions.
*/
static boolean won[] = new boolean[1 << 9];
static final int DONE = (1 << 9) - 1;
static final int OK = 0;
static final int WIN = 1;
static final int LOSE = 2;
static final int STALEMATE = 3;
/**
* Mark all positions with these bits set as winning.
*/
static void isWon(int pos) {
for (int i = 0; i < DONE; i++) {
if ((i & pos) == pos) {
won[i] = true;
}
}
}
/**
* Initialize all winning positions.
*/
static {
isWon((1 << 0) | (1 << 1) | (1 << 2));
isWon((1 << 3) | (1 << 4) | (1 << 5));
isWon((1 << 6) | (1 << 7) | (1 << 8));
isWon((1 << 0) | (1 << 3) | (1 << 6));
isWon((1 << 1) | (1 << 4) | (1 << 7));
isWon((1 << 2) | (1 << 5) | (1 << 8));
isWon((1 << 0) | (1 << 4) | (1 << 8));
isWon((1 << 2) | (1 << 4) | (1 << 6));
}
/**
* Compute the best move for white.
* @return the square to take
*/
int bestMove(int white, int black) {
int bestmove = -1;
loop: for (int i = 0; i < 9; i++) {
int mw = moves[i];
if (((white & (1 << mw)) == 0) && ((black & (1 << mw)) == 0)) {
int pw = white | (1 << mw);
if (won[pw]) {
// white wins, take it!
return mw;
}
for (int mb = 0; mb < 9; mb++) {
if (((pw & (1 << mb)) == 0) && ((black & (1 << mb)) == 0)) {
int pb = black | (1 << mb);
if (won[pb]) {
// black wins, take another
continue loop;
}
}
}
// Neither white nor black can win in one move, this will do.
if (bestmove == -1) {
bestmove = mw;
}
}
}
if (bestmove != -1) {
return bestmove;
}
// No move is totally satisfactory, try the first one that is open
for (int i = 0; i < 9; i++) {
int mw = moves[i];
if (((white & (1 << mw)) == 0) && ((black & (1 << mw)) == 0)) {
return mw;
}
}
// No more moves
return -1;
}
/**
* User move.
* @return true if legal
*/
boolean yourMove(int m) {
if ((m < 0) || (m > 8)) {
return false;
}
if (((black | white) & (1 << m)) != 0) {
return false;
}
black |= 1 << m;
return true;
}
/**
* Computer move.
* @return true if legal
*/
boolean myMove() {
if ((black | white) == DONE) {
return false;
}
int best = bestMove(white, black);
white |= 1 << best;
return true;
}
/**
* Figure what the status of the game is.
*/
int status() {
if (won[white]) {
return WIN;
}
if (won[black]) {
return LOSE;
}
if ((black | white) == DONE) {
return STALEMATE;
}
return OK;
}
/**
* Who goes first in the next game?
*/
boolean first = true;
/**
* The image for white.
*/
Image notImage;
/**
* The image for black.
*/
Image crossImage;
/**
* Initialize the applet. Resize and load images.
*/
public void init() {
notImage = getImage(getClass().getResource("images/not.gif"));
crossImage = getImage(getClass().getResource("images/cross.gif"));
}
/**
* Paint it.
*/
public void paint(Graphics g) {
Dimension d = getSize();
g.setColor(Color.black);
int xoff = d.width / 3;
int yoff = d.height / 3;
g.drawLine(xoff, 0, xoff, d.height);
g.drawLine(2 * xoff, 0, 2 * xoff, d.height);
g.drawLine(0, yoff, d.width, yoff);
g.drawLine(0, 2 * yoff, d.width, 2 * yoff);
int i = 0;
for (int r = 0; r < 3; r++) {
for (int c = 0; c < 3; c++, i++) {
if ((white & (1 << i)) != 0) {
g.drawImage(notImage, c * xoff + 1, r * yoff + 1, this);
} else if ((black & (1 << i)) != 0) {
g.drawImage(crossImage, c * xoff + 1, r * yoff + 1, this);
}
}
}
}
/**
* The user has clicked in the applet. Figure out where
* and see if a legal move is possible. If it is a legal
* move, respond with a legal move (if possible).
*/
public boolean mouseUp(Event evt, int x, int y) {
switch (status()) {
case WIN:
case LOSE:
case STALEMATE:
play(getClass().getResource("audio/return.au"));
white = black = 0;
if (first) {
white |= 1 << (int) (Math.random() * 9);
}
first = !first;
repaint();
return true;
}
// Figure out the row/colum
Dimension d = getSize();
int c = (x * 3) / d.width;
int r = (y * 3) / d.height;
if (yourMove(c + r * 3)) {
repaint();
switch (status()) {
case WIN:
play(getClass().getResource("audio/yahoo1.au"));
break;
case LOSE:
play(getClass().getResource("audio/yahoo2.au"));
break;
case STALEMATE:
break;
default:
if (myMove()) {
repaint();
switch (status()) {
case WIN:
play(getClass().getResource("audio/yahoo1.au"));
break;
case LOSE:
play(getClass().getResource("audio/yahoo2.au"));
break;
case STALEMATE:
break;
default:
play(getClass().getResource("audio/ding.au"));
}
} else {
play(getClass().getResource("audio/beep.au"));
}
}
} else {
play(getClass().getResource("audio/beep.au"));
}
return true;
}
public String getAppletInfo() {
return "TicTacToe by Arthur van Hoff";
}
}