BoardDisplay.java

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

// Used to display the contents of a game board
public class BoardDisplay implements ActionListener
{
	private Board board;
	private JButton[][] grid;
	private Piece selectedPiece;
	private Move selectedMove;
	private JFrame frame;
	private Color[][] colors;

	// Constructs a new display for displaying the given board
	public BoardDisplay(Board board)
	{
		this.board = board;
		grid = new JButton[board.getNumRows()][board.getNumCols()];
		colors = new Color[board.getNumRows()][board.getNumCols()];

        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        SwingUtilities.invokeLater(new Runnable()
        {
            public void run()
            {
                createAndShowGUI();
            }
        });

		//Wait until display has been drawn
        try
        {
        	while (frame == null || !frame.isVisible())
        		Thread.sleep(1);
		}
		catch(InterruptedException e)
		{
			e.printStackTrace();
			System.exit(1);
		}
	}

    /**
     * Create the GUI and show it.  For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private void createAndShowGUI()
    {
        //Create and set up the window.
        frame = new JFrame();
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.getContentPane().setLayout(new GridLayout(board.getNumRows(), board.getNumCols()));

		//Create each square as a button.
        for (int row = 0; row < grid.length; row++)
        	for (int col = 0; col < grid[row].length; col++)
        	{
				grid[row][col] = new JButton();
				grid[row][col].setOpaque(true);
				if ((row + col) % 2 == 0)
					grid[row][col].setBackground(new Color(155, 145, 115));
				else
					grid[row][col].setBackground(new Color(110, 85, 55));
				grid[row][col].setPreferredSize(new Dimension(50, 50));
				grid[row][col].setActionCommand(row + "," + col);
				grid[row][col].addActionListener(this);
				frame.getContentPane().add(grid[row][col]);
			}

		//Show the pieces
		showBoard();

        //Display the window.
        frame.pack();
        frame.setVisible(true);
    }

	//Called when a square is clicked.
    public void actionPerformed(ActionEvent event)
    {
		//Determine location of clicked button.
		String command = event.getActionCommand();
		int comma = command.indexOf(",");
		int row = Integer.parseInt(command.substring(0, comma));
		int col = Integer.parseInt(command.substring(comma + 1));
		Location loc = new Location(row, col);

		if (selectedPiece == null)
		{
			//we have just selected a piece for the first time.
			selectedPiece = board.get(loc);
			clearColors();
			if (selectedPiece != null)
				setColor(loc, Color.YELLOW);
		}
		else if (loc.equals(selectedPiece.getLocation()))
		{
			//we are deselecting the piece
			selectedPiece = null;
			selectedMove = null;
			clearColors();
		}
		else
		{
			//we have selected a move
			selectedMove = new Move(selectedPiece, loc);
			setColor(loc, Color.YELLOW);
		}
	}

	//Redraws the board to include the pieces and border colors.
	public void showBoard()
	{
		for (int row = 0; row < grid.length; row++)
			for (int col = 0; col < grid[row].length; col++)
			{
				Location loc = new Location(row, col);

				Piece piece = board.get(loc);

				Icon icon = null;
				if (piece != null)
				{
					//System.out.println(loc);
					grid[row][col].setForeground(piece.getColor());
					icon = new ImageIcon(piece.getImageFileName());
				}
				grid[row][col].setIcon(icon);

				Color color = colors[row][col];

				if (color == null)
					grid[row][col].setBorder(null);
				else
					grid[row][col].setBorder(BorderFactory.createLineBorder(color));
			}
	}

	// Waits for the user to select a move and returns this move.
	public Move selectMove()
	{
		try
		{
			selectedPiece = null;
			selectedMove = null;
			while (selectedMove == null)
				Thread.sleep(1);
			Move move = selectedMove;
			selectedPiece = null;
			selectedMove = null;
			return move;
		}
		catch(InterruptedException e)
		{
			e.printStackTrace();
			System.exit(1);
			return null;
		}
	}

	// Sets the title of the window.
	public void setTitle(String title)
	{
		frame.setTitle(title);
	}

	// Sets the color of the border for the given location, and redraws it.
	public void setColor(Location loc, Color color)
	{
		colors[loc.getRow()][loc.getCol()] = color;
		showBoard();
	}

	// Clears all border colors and redraws the board.
	public void clearColors()
	{
		for (int row = 0; row < colors.length; row++)
			for (int col = 0; col < colors[row].length; col++)
				colors[row][col] = null;
		showBoard();
	}
}