Thread: Connect 4 program

I'm not supposed to change anything but the Board class, which simply implements the Connect4Board interface. The Board.java class shouldnt do any drawing, just represent the board itself

This is the central class:

package extracredit02;
 
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
 
/**
 * A computer game version of 'Connect 4'.
 * 
 * Undocumented code - beware!  This code is not the best example of
 * programming I have done, I am rushing too much.
 * 
 * @author 
 */
public class Connect4 extends JPanel implements ActionListener, MouseListener, MouseMotionListener
{
    Connect4AI[] players = new Connect4AI[] {null, new NaiveAI(), new StubbornAI(), new SmartAI()};
    String[] playerNames = new String[] {"Human", players[1].getName(), players[2].getName(), players[3].getName()};
 
    int[] playerAI = new int[2];  // Red player is player 0
    int[] playerColor   = new int[] {Connect4Board.RED, Connect4Board.BLACK};
    String[] colorName  = new String[] {"red", "", "black"};
 
    JLabel message = new JLabel();
 
    boolean gameInProgress = false;
 
    Connect4Board board = new Board();
 
    JMenuItem menuItem;
 
    int proposedColumn = -1;
    int proposedRow = -1;
    int playerTurn = 0;
 
    JFrame frame;
 
    int[][] drawState = new int[8][8];
 
    /**
     * The application entry point.
     * 
     * @param args Unused.
     */    
    static public void main (String[] args)
    {
        Connect4 game = new Connect4();        
 
        game.frame = new JFrame ("CP SC 2010 - Connect 4");
        game.frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        game.frame.setBounds(100, 100, 800, 850);
 
        Container contents = game.frame.getContentPane();
        contents.setLayout(new BorderLayout());
 
        Container main = new JPanel();
        main.setLayout(new BorderLayout());
 
        game.message = new JLabel ("Welcome.  Please use the menu to start the game.");
        game.message.setFont(new Font("Arial", Font.BOLD, 20));
        main.add(game.message, BorderLayout.SOUTH);
        main.add(game, BorderLayout.CENTER);
 
        JMenuBar menuBar = new JMenuBar();
 
        JMenu gameMenu = new JMenu("Game");
        game.menuItem = new JMenuItem("Start game");
        gameMenu.add(game.menuItem);
        game.menuItem.addActionListener(game);
        game.addMouseListener(game);
        game.addMouseMotionListener(game);
        menuBar.add(gameMenu);
 
        contents.add(main, BorderLayout.CENTER);
        game.frame.setJMenuBar(menuBar);
        game.frame.setVisible(true);
    }
 
    synchronized public void actionPerformed (ActionEvent e)
    {
        if (gameInProgress)
        {
            gameInProgress = false;
            menuItem.setText("Start game");
            message.setText("Game aborted.  Please use the menu to start the game.");
            message.repaint();            
        }
        else
        {
            message.setText ("Select players.");
            message.repaint();
            try
            {
                promptForPlayers();
            }
            catch (Exception ex)
            {
                message.setText("Please use the menu to start the game.");
                message.repaint();
                return;
            }
            gameInProgress = true;
            board.clear();
            drawState = new int[8][8];
            menuItem.setText("Stop game");
            playerTurn = 1;
            advancePlayer();
        }
    }
 
    synchronized private void advancePlayer()
    {
        for (int row = 0; row < 8; row++)
            for (int column = 0; column < 8; column++)
                drawState[row][column] = board.getSpaceContents(row, column);
 
        proposedColumn = -1;
        proposedRow = -1;
 
        if (board.getWinner() != 0)
        {
            gameInProgress = false;
            menuItem.setText("Start game");
            message.setText("The game is over.  Please use the menu to start the game.");
            repaint();
            message.repaint();
            JOptionPane.showMessageDialog(frame, "The " + colorName[playerColor[playerTurn]+1] + " player wins!\nCongratulations " + playerNames[playerAI[playerTurn]]);
            return;
        }
 
        if (board.isFull())
        {
            gameInProgress = false;
            menuItem.setText("Start game");
            message.setText("The game is over.  Please use the menu to start the game.");
            repaint();
            message.repaint();
            JOptionPane.showMessageDialog(frame, "It's a tie.");
            return;            
        }
 
        playerTurn = (playerTurn + 1) % 2;
        if (players[playerAI[playerTurn]] != null)
        {
            message.setText("It is " + playerNames[playerAI[playerTurn]] + " (" + colorName[playerColor[playerTurn]+1] + "s) turn, please wait.");
            new Thread(new AITurn()).start();
        }
        else
            message.setText("It is your turn, " + colorName[playerColor[playerTurn]+1] + " player.  Click the mouse to drop the piece.");
        repaint();
        message.repaint();
    }
 
    class AITurn implements Runnable
    {
        public void run ()
        {
            if (gameInProgress == false)
                return;
 
            synchronized (this)
            {
                long time = System.currentTimeMillis();
                int column = players[playerAI[playerTurn]].makeMove(board, playerColor[playerTurn]);
                if (playerColor[playerTurn] == Connect4Board.RED)
                    board.addRedChecker(column);
                else
                    board.addBlackChecker(column);
                if (System.currentTimeMillis() - time < 1000)
                { try { Thread.sleep(1000); } catch (Exception e) {}}
                repaint();
                advancePlayer();
            }
        }
    }
 
    public void promptForPlayers ()
    {
        playerAI[0] = 0;
        playerAI[1] = 0;
 
        String s = (String) JOptionPane.showInputDialog (frame, "Who should play the red pieces?",
                                                         "Select a player",
                                                         JOptionPane.PLAIN_MESSAGE, null,
                                                         playerNames, "Human");
        for (int i = 0; i < playerNames.length; i++)
            if (s.equals(playerNames[i]))
            {
                playerAI[0] = i;
            }
 
        s = (String) JOptionPane.showInputDialog (frame, "Who should play the black pieces?",
                                                         "Select a player",
                                                         JOptionPane.PLAIN_MESSAGE, null,
                                                         playerNames, "Human");
        for (int i = 0; i < playerNames.length; i++)
            if (s.equals(playerNames[i]))
            {
                playerAI[1] = i;
            }
    }
 
    public void paint (Graphics g)
    {
        int width = this.getSize().width;
        int height = this.getSize().height;
 
        g.setColor(new Color(0.6f, 0.7f, 1.0f));
        g.fillRect(0, 0, width, height);
 
        g.setColor(Color.DARK_GRAY);
        g.fillRect(50, 20, 704, 704);
 
        for (int row = 0; row < 8; row++)
            for (int column = 0; column < 8; column++)
            {
                int space = drawState[row][column];
                if (space == Connect4Board.RED)
                    g.setColor(Color.RED);
                else if (space == Connect4Board.BLACK)
                    g.setColor(Color.BLACK);
                else
                    g.setColor(Color.WHITE);
                g.fillOval (59 + 88*column, 645 - 88*row, 70, 70);
            }
 
        if (proposedColumn >= 0 && proposedRow >= 0)
        {
            g.setColor(new Color(0.7f, 1.0f, 0.7f));
            g.fillOval (59 + 88*proposedColumn, 645 - 88*proposedRow, 70, 70);
        }
    }
 
    public void mouseMoved (MouseEvent e)
    {
        if (!gameInProgress || players[playerAI[playerTurn]] != null)
            return;
 
        int x = e.getX();
 
        int nextColumn = (x - 50) / 88;
        int nextRow = 8;
        while (nextColumn >= 0 && nextColumn <= 7 && nextRow > 0 && board.getSpaceContents(nextRow-1, nextColumn) == Connect4Board.NONE)
            nextRow--;
 
        if (x < 50 || nextColumn < 0 || nextColumn > 7 || nextRow < 0 || nextRow > 7)
        {
            nextColumn = -1;
            nextRow = -1;
        }
 
        if (nextColumn != proposedColumn || nextRow != proposedRow)
        {
            proposedRow = nextRow;
            proposedColumn = nextColumn;
            repaint();
        }
    }
 
    public void mouseDragged (MouseEvent e)
    {
        mouseMoved(e);
    }
 
    public void mouseClicked (MouseEvent e)
    {
 
    }
 
    public void mousePressed (MouseEvent e)
    {
 
    }
 
    public void mouseReleased (MouseEvent e)
    {
        if (players[playerAI[playerTurn]] != null)
            return;
 
        if (proposedRow >= 0 && proposedColumn >= 0)
        {
            if (playerColor[playerTurn] == Connect4Board.BLACK)
                board.addBlackChecker(proposedColumn);
            else
                board.addRedChecker(proposedColumn);
 
            advancePlayer();
        }
    }
 
    public void mouseEntered (MouseEvent e)
    {
 
    }
 
    public void mouseExited (MouseEvent e)
    {
 
    }
}

This is the class I'm supposed to write:

package extracredit02;
 
public class Board implements Connect4Board
{
 
	/**
     * This method will clear the board's grid so that all spaces
     * are marked as having 'no checker' in each space.
     */
    public void clear()
    {
 
    }
 
    /**
     * This method adds a red checker to the specified column, if
     * possible.  (If this column is full, nothing happens.)  If
     * there is space in the column for another checker, then
     * a red checker will be placed in the lowest unoccupied
     * space in the column.
     * 
     * Column 0 corresponds to the left side of the grid.
     * 
     * @param column A column number, from 0 to 7.
     */
	public void addRedChecker(int column) {
		// TODO Auto-generated method stub
 
	}
 
	/**
     * This method adds a black checker to the specified column, if
     * possible.  (If this column is full, nothing happens.)  If
     * there is space in the column for another checker, then
     * a black checker will be placed in the lowest unoccupied
     * space in the column.
     * <p>
     * 
     * Column 0 corresponds to the left side of the grid.
     * 
     * @param column A column number, from 0 to 7.
     */
	public void addBlackChecker(int column) {
 
 
	}
 
	/**
     * This method removes the topmost checker from the specified
     * column.  If the column is empty, nothing happens.
     * 
     * Column 0 corresponds to the left side of the grid.
     * 
     * @param column A column number, from 0 to 7.
     */
	public void removeChecker(int column) {
		// TODO Auto-generated method stub
 
	}
 
	 /**
     * Returns true if the board is full of checkers.
     * 
     * @return true if the board is full of checkers.
     */
	public boolean isFull() {
		// TODO Auto-generated method stub
		return false;
	}
 
	/**
     * Returns an integer describing the checker in the specified
     * space in the grid.  Row 0 corresponds to the bottom
     * of the grid, column 0 corresponds to the left side of the grid.
     * <p>
     * 
     * Returns the RED constant (defined above) if the space has
     * a red checker in it, the BLACK constant (defined above) if the
     * space has a black checker in it, and NONE (defined above) if
     * there is no checker in the space.
     * <p>
     * 
     * If the row or column number is outside the range 0..7, this
     * method will return NONE (defined above).
     * 
     * @param row A row number, from 0 to 7.
     * @param column A column number, from 0 to 7.
     * @return An integer that describes the contents of the space.
     */
	public int getSpaceContents(int row, int column) {
		// TODO Auto-generated method stub
		return 0;
	}
 
	 /**
     * Returns true if the board has four red checkers together in a row,
     * column, or diagonal line.  This would indicate a win for red.
     * 
     * @return True if there are four red checkers in a line.
     */
	public boolean redHasWon() {
		// TODO Auto-generated method stub
		return false;
	}
 
	/**
     * Returns true if the board has four black checkers together in a row,
     * column, or diagonal line.  This would indicate a win for black.
     * 
     * @return True if there are four black checkers in a line.
     */
	public boolean blackHasWon() {
		// TODO Auto-generated method stub
		return false;
	}
 
	/**
     * Returns an integer describing the winner of this game, if any.
     * <p>
     * 
     * Returns the RED constant (defined above) if red has won the
     * game, the BLACK constant (defined above) if black has won the
     * game, and NONE (defined above) if no one has won yet.
     * 
     * @return An integer that describes the winning color, if any.
     */
	public int getWinner() {
		// TODO Auto-generated method stub
		return 0;
	}
 
}

appreciate any help/clarification

I suppose I'm not sure how to actually get the connect4 class to paint the red or black checker piece when I click. As it is, when it runs, it paints the outline of the board but doesn't paint anything when I click. Would I write an onclick method within the board class?

How do I get a checker piece to fall into the lowest position in a row when I click?