board.java

This the OXO example code plus the presentation. It is intended to provide you with some clues about

/**
 * Represents a OXO board . 
 * Each square can either be blank or hold a value
 * 
 * @author Ian Bradley 
 * @version 1.0 March 2008
 */
public class Board
{
    

    private final String BLANK = "";
    
    private String [][] board;

    /**
     * Constructor for objects of class Board
     */
    public Board()
    {
        board = new String[3][3];
        for ( int r = 0 ; r < 3 ; r++ )
            for ( int c = 0 ; c < 3 ; c++ )
                board[r][c] = BLANK;
    }

    /**
     * Sets a cell of the board to a specific character.
     * 
     * @param  coord   the Coord of the cellrow
     * @param  ch  the value for the cell
     */
    public void setCell( Coord coord, String ch)
    {
        board[coord.getRow()][coord.getColumn()] = ch;
    }
    
    /**
     * Gets the value held in the given cell.
     * 
     * @param  coord row column pair for cell
     * @return the value for the cell
     */
    public String getCellValue( Coord coord)
    {
         return board[coord.getRow()][coord.getColumn()] ;
    }
    
    /**
     * tests to see if there is still space on the board.
     * 
     * @return true if spaces otherwise false 
     */
    public boolean stillSpace()
    {
        for ( int r = 0 ; r < board.length ; r++ )
            for ( int c = 0 ; c < board[r].length ; c++ )
                 if (board[r][c].equals(BLANK))
                    return true;
        return false;
    }
    
    /**
     * checks for a win.
     * 
     * @return true if a winning line otherwise false
     */
    public boolean checkWin()
    {
        return checkRows() || checkColumns() || checkDiagonals();
    }
    
    private boolean checkRows()
    {
        for (int r = 0 ; r < board.length ; r++ )
            if ( !( board[r][0].equals(BLANK) ))
                if ( ( board[r][0] == board[r][1] ) && ( board[r][1] == board[r][2] ))
                    return true;
       return false;
    }
    
    private boolean checkColumns()
    {
        for (int c = 0 ; c < board.length ; c++ )
            if ( !( board[0][c].equals(BLANK)))
                if ( ( board[0][c] == board[1][c] ) && ( board[1][c] == board[2][c] ))
                    return true;
       return false;
    }
    
    private boolean checkDiagonals()
    {
        if ( !( board[0][0].equals(BLANK) ))
           if ( (board[0][0] == board[1][1] ) && ( board[1][1] == board[2][2]) )
            return true;
        if ( !(board[0][2].equals(BLANK) ))
           if ( (board[0][2] == board[1][1] ) && ( board[1][1] == board[2][0]) )
            return true;    
        return false;
    }
    
    public Coord getFirstEmptyCell()
    {
        for ( int r = 0 ; r < board.length ; r++ )
            for ( int c = 0 ; c < board[r].length ; c++ )
                 if ((board[r][c].equals(BLANK) ))
                    return new Coord(r,c);
        return null;
    }     
    
    
    
    
}