NoughtsAndCrosses.java

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class NoughtsAndCrosses {
    public static void main(String[] args) {
        NoughtsAndCrossesJFrame frame = new NoughtsAndCrossesJFrame();
        frame.setDefaultCloseOperation( JFrame.EXIT_ON_CLOSE);
        // Set to a reasonable size.
        frame.setSize(1000, 700);
        frame.setVisible(true);
    }
}

class NoughtsAndCrossesJFrame extends JFrame implements ActionListener, MouseListener {

    /**
    *   Program:    NoughtsAndCrosses.java
    *   Purpose:    2 player game of Xs and Os (also known as "Tic-Tac-Toe").
    *   Creator:    Chris Clarke
    *   Created:    17.12.2006
    *   Modified:   05.05.2013 Updated to JFrame
    */

    private Label       lbl1;
    private Choice      ch1;
    private Button      btnPlay;
    int[][]         grid;       // 3 by 3 grid
    int         sqr_X, sqr_Y;   // the co-ordinates of square in the grid
    int         toPlay=-1;
    boolean         paint=true;
    public static final int NOUGHTS = 0;
    public static final int CROSSES = 1;
    public static final int STARTX = 200;
    public static final int STARTY = 200;
    public static final int SQUARESIZE = 100;

    public NoughtsAndCrossesJFrame() {
        setTitle("Noughts And Crosses by Chris Clarke");
        // Build control panel.
        Panel panel = new Panel(); // Uses flow layout

        lbl1 = new Label("Who goes first >>>");
        panel.add(lbl1);

        ch1 = new Choice();
        ch1.add("Noughts 0");
        ch1.add("Crosses X");
        panel.add(ch1);

        btnPlay = new Button("New Game");
        btnPlay.addActionListener(this);
        panel.add(btnPlay);

        add(panel, BorderLayout.NORTH);

        grid = new int[3][3];
        clearGrid();
        addMouseListener(this);
        this.setFocusable(true);
    }

    public void paint(Graphics g) {
        // if game is won, do nothing
        if (!paint) return;
        boolean foundSpace=false;

        g.setColor(Color.WHITE);    // clear win/draw message
        g.fillRect(STARTX+4*SQUARESIZE, STARTY+70, 400, -200);

        g.setColor(Color.BLACK);
        drawEmptyGrid(g);
        g.setFont(new Font("Courier", Font.PLAIN, 72));
        for (int y=0; y<=2; y++) {
            for (int x=0; x<=2; x++) {
                if (grid[y][x]==NOUGHTS) {
                    // draw Nought
                    g.drawString("O", (STARTX+25+(x*SQUARESIZE)),
                     (STARTY+80+(y*SQUARESIZE)));
                } else if (grid[y][x]==CROSSES) {
                    //draw Cross
                    g.drawString("X", (STARTX+25+(x*SQUARESIZE)),
                     (STARTY+80+(y*SQUARESIZE)));
                } else {
                    g.setColor(Color.WHITE);
                    g.fillRect(STARTX+1+(x*SQUARESIZE),
                     STARTY+1+(y*SQUARESIZE), SQUARESIZE-1, SQUARESIZE-1);
                    g.setColor(Color.BLACK);
                }//end if
            }//end for x
        }//end for y

        for (int shape=NOUGHTS; shape<=CROSSES; shape++)
            if (isLine(g, shape)) {
                String winner;
                if (shape==NOUGHTS)
                    winner="O wins";
                else
                    winner="X wins";
                g.drawString(winner, STARTX+4*SQUARESIZE, STARTY+50);
                paint=false;
                return;
            }
        // look for blank spaces
        for (int y=0; y<=2; y++)
            for (int x=0; x<=2; x++)
                if (grid[y][x]==-1) foundSpace=true;
        // if board is full and neither side has won
        if (!foundSpace)
            g.drawString("Draw", STARTX+4*SQUARESIZE, STARTY+50);
    }

    public boolean isLine(Graphics g, int shape) {
    // is there a line of three "x"s or "o"s (horizontal/vertical/diagonal)
        g.setColor(Color.RED);
        if ((grid[0][0]==shape)&&(grid[0][1]==shape)&&(grid[0][2]==shape)) {
            g.drawLine(STARTX, STARTY+50, STARTX+3*SQUARESIZE, STARTY+50);
            return true;
        }
        if ((grid[1][0]==shape)&&(grid[1][1]==shape)&&(grid[1][2]==shape)) {
            g.drawLine(STARTX, STARTY+150, STARTX+3*SQUARESIZE, STARTY+150);
            return true;
        }
        if ((grid[2][0]==shape)&&(grid[2][1]==shape)&&(grid[2][2]==shape)) {
            g.drawLine(STARTX, STARTY+250, STARTX+3*SQUARESIZE, STARTY+250);
            return true;
        }
        if ((grid[0][0]==shape)&&(grid[1][0]==shape)&&(grid[2][0]==shape)) {
            g.drawLine(STARTX+50, STARTY, STARTX+50, STARTY+3*SQUARESIZE);
            return true;
        }
        if ((grid[0][1]==shape)&&(grid[1][1]==shape)&&(grid[2][1]==shape)) {
            g.drawLine(STARTX+150, STARTY, STARTX+150, STARTY+3*SQUARESIZE);
            return true;
        }
        if ((grid[0][2]==shape)&&(grid[1][2]==shape)&&(grid[2][2]==shape)) {
            g.drawLine(STARTX+250, STARTY, STARTX+250, STARTY+3*SQUARESIZE);
            return true;
        }
        if ((grid[0][0]==shape)&&(grid[1][1]==shape)&&(grid[2][2]==shape)) {
            g.drawLine(STARTX, STARTY, STARTX+3*SQUARESIZE,
             STARTY+3*SQUARESIZE);
            return true;
        }
        if ((grid[2][0]==shape)&&(grid[1][1]==shape)&&(grid[0][2]==shape)) {
            g.drawLine(STARTX+3*SQUARESIZE, STARTY, STARTX,
             STARTY+3*SQUARESIZE);
            return true;
        }
        return false;
    }

    public void drawEmptyGrid(Graphics g) {
        ///
        g.drawLine(STARTX, STARTY+SQUARESIZE, STARTX+3*SQUARESIZE,
         STARTY+SQUARESIZE);
        g.drawLine(STARTX, STARTY+2*SQUARESIZE, STARTX+3*SQUARESIZE,
         STARTY+2*SQUARESIZE);
        g.drawLine(STARTX+SQUARESIZE, STARTY, STARTX+SQUARESIZE,
         STARTY+3*SQUARESIZE);
        g.drawLine(STARTX+2*SQUARESIZE, STARTY, STARTX+2*SQUARESIZE,
         STARTY+3*SQUARESIZE);
    }

    public void clearGrid() {
        for (int i=0; i<=2; i++)
            for (int j=0; j<=2; j++)
                grid[i][j]=-1;
    }

    public void reset() {
        clearGrid();
        toPlay=-1;
        paint=true;
        repaint();
    }

    public void mouseClicked(MouseEvent event) {
        if ((event.getX()<STARTX)||(event.getX()>STARTX+3*SQUARESIZE))
            return;
        if ((event.getY()<STARTY)||(event.getY()>STARTY+3*SQUARESIZE))
            return;
        sqr_X=(event.getX()-STARTX)/SQUARESIZE;
        sqr_Y=(event.getY()-STARTY)/SQUARESIZE;
        if (toPlay==-1)
            toPlay=ch1.getSelectedIndex();
        if (grid[sqr_Y][sqr_X]!=-1)
            return;
        grid[sqr_Y][sqr_X]=toPlay;
        if (toPlay==NOUGHTS)
            toPlay=CROSSES;
        else
            toPlay=NOUGHTS;
        repaint();
    }

    public void mouseEntered(MouseEvent event) {}

    public void mouseExited(MouseEvent event) {}

    public void mousePressed(MouseEvent event) {}

    public void mouseReleased(MouseEvent event) {}

    // get user involvement in menu item
    public void actionPerformed(ActionEvent e) {
        if (e.getSource() == btnPlay)
            reset();
    }
}