Chess program

**Nepomuk** · Aug 29 '07, 01:07 PM

Originally posted by needhelp20

how to make a appropriate move for each pawns? I knew that I should used some HashMap or classes for every pawn,but I don't know how to implement in code...

Here is my code:

[CODE=java]
...
// Add a few pieces to the board but I don't know is it ok? maybe it should be in some loop?

JLabel piece = new JLabel( new ImageIcon("pw.p ng") );
JPanel panel = (JPanel)chessBo ard.getComponen t( 8 );
panel.add( piece );
...
}
...
[/CODE]

First of all: It is ok to add the pieces in that way, but you can certainly save code by adding any pieces which have the same Image (if there are more than 2 with the same Image) in a loop.

OK, next Question. Indeed, a HashMap would be a good idea. But first of all, I would create an interface for all figures. Something like this:
[CODE=java]
public interface Figure {

// Every figure has to be moved - but not to an illegal Field
public void move(int x, int y) throws IllegalFieldExc eption;

// You have to be able to find out, where a figure is.
public int xPosition();
public int yPosition();

// Of course, you have to know, if a figure is still on the field
public boolean captured();

// And you have to be able to capture figures
public void capture();
}
}
[/CODE]
From this, you implement the various figures. When done, you can add them to your Field:
[CODE=java]
HashMap[] figure = new Figure[16];
for(int i=0;i<8;i++)
{
Figures.add("Pa wn" + i;new Pawn(i,1));
}
// Add the other figures
...
[/CODE]And continue from that.
The rules about how you can move a figure (e.g. a Pawn) should be programmed in the "move" method.

**needhelp20** · Aug 29 '07, 02:18 PM

In this program The GUI must enable:

* drag'n'drop of pieces,
* entering moves with the keyboard,
* displaying information concerning the current move,
* highlighting the active player.
* forbid illegal moves,
* remember game history (each move),
* enable storing/loading a game to/from a file,

maybe somebode can do that whit this code...
I will be very gratefull.

**sicarie** · Aug 29 '07, 02:42 PM

Those look like things you can do if you read nepomuk's post and implement the suggestions. Or are you stuck on one of them?

**Nepomuk** · Aug 29 '07, 02:47 PM

Originally posted by needhelp20

* forbid illegal moves,

The "IllegalFieldEx ception" (you can call it "IllegalMoveExc eption" of course) can take care of most of that. You just have to catch it and react.

Originally posted by needhelp20

* remember game history (each move),

You could create a container class called Move, which saves a Move (from where, to where, which Figure) and a Vector of Moves. The Vector can then save the History of all Moves.

However, there might be a better solution.

Originally posted by needhelp20

* enable storing/loading a game to/from a file,

Read this article about reading and writing files.

**Nepomuk** · Aug 29 '07, 02:51 PM

Originally posted by nepomuk

The "IllegalFieldEx ception" (you can call it "IllegalMoveExc eption" of course) can take care of most of that. You just have to catch it and react.

Actually, you could also implement a function called public boolean legalMove(int x, int y) in the interface to test, if a Move is legal. That might save some work.

**needhelp20** · Aug 31 '07, 07:55 AM

I stuck in add pawns, I can't see them on the board. probably I should add this by JPanel but in that way it doesn't work...

Code:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import java.io.*;
import java.util.*;
import java.util.HashMap;
 
public class ChessBoard extends JFrame implements MouseListener, MouseMotionListener
{
	JLayeredPane layeredPane;
	JPanel chessBoard;
	JLabel chessPiece;
	int xAdjustment;
	int yAdjustment;
 	private JFileChooser chooser;
 	Component prev;
 	
    private static HashMap WhiteFigures = new HashMap();
    private static HashMap BlackFigures = new HashMap();
 
 
	public ChessBoard()
	{
		
		
		setTitle("Chessboard by Radek");
		
		chooser = new JFileChooser();
		chooser.setCurrentDirectory(new File("."));

		JMenuBar menuBar = new JMenuBar();
		setJMenuBar(menuBar);
				
		JMenu menu = new JMenu("File");
		menuBar.add(menu);
		
		JMenu menu1 = new JMenu("Edit");
		menuBar.add(menu1);
		

		JMenuItem openItem = new JMenuItem("Open");
		menu.add(openItem);
		openItem.addActionListener(new ActionListener()
		{
			public void actionPerformed(ActionEvent evt)
			{
				int r = chooser.showOpenDialog(null);
				if(r == JFileChooser.APPROVE_OPTION)
				{
					String name = chooser.getSelectedFile().getPath();
				}
			}
		});
		
		JMenuItem saveItem = new JMenuItem("Save");
		menu.add(saveItem);
		
		JMenuItem exitItem = new JMenuItem("Exit");
		menu.add(exitItem);
		exitItem.addActionListener(new ActionListener()
		{
			public void actionPerformed(ActionEvent event){
				System.exit(0);
			}
		});
		
		JMenuItem zoomItem = new JMenuItem("size +");
		menu1.add(zoomItem);
		zoomItem.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent evt){
				setSize (300, 300);
			}
		});
		
		JMenuItem zoomOutItem = new JMenuItem("size -");
		menu1.add(zoomOutItem);
		zoomOutItem.addActionListener(new ActionListener(){
			public void actionPerformed(ActionEvent evt){
				setSize (630, 670);
			}
		});
		
		Dimension Size = new Dimension(600, 600);
 
		//  Use a Layered Pane for this application
 
		layeredPane = new JLayeredPane();
		getContentPane().add(layeredPane);
		layeredPane.setPreferredSize( Size );
		layeredPane.addMouseListener( this );
		layeredPane.addMouseMotionListener( this );
 
		//  Add a chess board to the Layered Pane
 
		chessBoard = new JPanel();
		layeredPane.add(chessBoard, JLayeredPane.DEFAULT_LAYER);
		chessBoard.setLayout( new GridLayout(8, 8) );
		chessBoard.setPreferredSize( Size );
		chessBoard.setBounds(2, 2, Size.width, Size.height);
		
		
 
		for (int i = 0; i < 64; i++)
		{
			JPanel square = new JPanel( new BorderLayout() );
			chessBoard.add( square );
 
			int row = (i / 8) % 2;
			if (row == 0)
				square.setBackground( i % 2 == 0 ? Color.black : Color.white );
			else
				square.setBackground( i % 2 == 0 ? Color.white : Color.black );
		}
 
		Figure[] whiteFigure = new Figure[16];
		

		// Add Pawns
        for(int i=0;i<8;i++)
        {
            whiteFigure[i] = new Pawn(1,i);
            WhiteFigures.put("pw.png" + i, whiteFigure[i]);
        }
		//add king
		whiteFigure[12] = new King(0,4);
        WhiteFigures.put("kgw.png", whiteFigure[12]);

	/*	JLabel piece = new JLabel( new ImageIcon("pw.png") );
		JPanel panel = (JPanel)chessBoard.getComponent( 8 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("pw.png") );
		panel = (JPanel)chessBoard.getComponent( 9 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("pw.png") );
		panel = (JPanel)chessBoard.getComponent( 10 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("pw.png") );
		panel = (JPanel)chessBoard.getComponent( 11 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("pw.png") );
		panel = (JPanel)chessBoard.getComponent( 12 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("pw.png") );
		panel = (JPanel)chessBoard.getComponent( 13 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("pw.png") );
		panel = (JPanel)chessBoard.getComponent( 14 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("pw.png") );
		panel = (JPanel)chessBoard.getComponent( 15 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("ww.png") );
		panel = (JPanel)chessBoard.getComponent( 0 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("ww.png") );
		panel = (JPanel)chessBoard.getComponent( 7 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("hw.png") );
		panel = (JPanel)chessBoard.getComponent( 1 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("hw.png") );
		panel = (JPanel)chessBoard.getComponent( 6 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("bw.png") );
		panel = (JPanel)chessBoard.getComponent( 2 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("bw.png") );
		panel = (JPanel)chessBoard.getComponent( 5 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("qw.png") );
		panel = (JPanel)chessBoard.getComponent( 3 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("kgw.png") );
		panel = (JPanel)chessBoard.getComponent( 4 );
		panel.add( piece );
		
		//black
		
		piece = new JLabel( new ImageIcon("pc.png") );
		panel = (JPanel)chessBoard.getComponent( 48 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("pc.png") );
		panel = (JPanel)chessBoard.getComponent( 49 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("pc.png") );
		panel = (JPanel)chessBoard.getComponent( 50 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("pc.png") );
		panel = (JPanel)chessBoard.getComponent( 51 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("pc.png") );
		panel = (JPanel)chessBoard.getComponent( 52 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("pc.png") );
		panel = (JPanel)chessBoard.getComponent( 53 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("pc.png") );
		panel = (JPanel)chessBoard.getComponent( 54 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("pc.png") );
		panel = (JPanel)chessBoard.getComponent( 55 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("wc.png") );
		panel = (JPanel)chessBoard.getComponent( 56 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("wc.png") );
		panel = (JPanel)chessBoard.getComponent( 63 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("hc.png") );
		panel = (JPanel)chessBoard.getComponent( 57 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("hc.png") );
		panel = (JPanel)chessBoard.getComponent( 62 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("bc.png") );
		panel = (JPanel)chessBoard.getComponent( 58 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("bc.png") );
		panel = (JPanel)chessBoard.getComponent( 61 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("qc.png") );
		panel = (JPanel)chessBoard.getComponent( 59 );
		panel.add( piece );
		piece = new JLabel( new ImageIcon("kgc.png") );
		panel = (JPanel)chessBoard.getComponent( 60 );
		panel.add( piece );
*/
		
	}
	

	public void mousePressed(MouseEvent e)
	{
		chessPiece = null;
		Component c =  chessBoard.findComponentAt(e.getX(), e.getY());
 		prev = c.getParent();
		if (c instanceof JPanel) return;
 
		Point parentLocation = c.getParent().getLocation();
		xAdjustment = parentLocation.x - e.getX();
		yAdjustment = parentLocation.y - e.getY();
		chessPiece = (JLabel)c;
		chessPiece.setLocation(e.getX() + xAdjustment, e.getY() + yAdjustment);
		chessPiece.setSize(chessPiece.getWidth(), chessPiece.getHeight());
		layeredPane.add(chessPiece, JLayeredPane.DRAG_LAYER);
	}
 
 
	public void mouseDragged(MouseEvent me)
	{
		if (chessPiece == null) return;
 
		chessPiece.setLocation(me.getX() + xAdjustment, me.getY() + yAdjustment);
	 }
 
 
	public void mouseReleased(MouseEvent e)
	{
		
try
	{
		if (chessPiece == null) return;
 
		chessPiece.setVisible(false);
		Component c =  chessBoard.findComponentAt(e.getX(), e.getY());
 
		if (c instanceof JLabel)
		{
   Container parent = (Container)prev;
   parent.add( chessPiece );
		}
		else
		{
			Container parent = (Container)c;
			parent.add( chessPiece );
		}
 
		chessPiece.setVisible(true);

	}catch(NullPointerException exception)
	{
		Container parent = (Container)prev;
		parent.add( chessPiece );
		chessPiece.setVisible(true);
	}
	}
 
	public void mouseClicked(MouseEvent e) {}
	public void mouseMoved(MouseEvent e) {}
	public void mouseEntered(MouseEvent e) {}
	public void mouseExited(MouseEvent e) {}
 
 
 
	public static void main(String[] args)
	{
		JFrame frame = new ChessBoard();
		frame.setDefaultCloseOperation( DISPOSE_ON_CLOSE );
		frame.pack();
		frame.setResizable( false );
		frame.setLocationRelativeTo( null );
		frame.setVisible(true);
		

        
        
        }
	 }

**Nepomuk** · Aug 31 '07, 08:53 AM

Originally posted by needhelp20

I stuck in add pawns, I can't see them on the board. probably I should add this by JPanel but in that way it doesn't work...

Code:

 
		Figure[] whiteFigure = new Figure[16];

		// Add Pawns
        for(int i=0;i<8;i++)
        {
            whiteFigure[i] = new Pawn(1,i);
            WhiteFigures.put("pw.png" + i, whiteFigure[i]);
        }
		//add king
		whiteFigure[12] = new King(0,4);
        WhiteFigures.put("kgw.png", whiteFigure[12]);

	/*	JLabel piece = new JLabel( new ImageIcon("pw.png") );
		JPanel panel = (JPanel)chessBoard.getComponent( 8 );
		panel.add( piece );
		...
		
		//black
		
		piece = new JLabel( new ImageIcon("pc.png") );
		panel = (JPanel)chessBoard.getComponent( 48 );
		panel.add( piece );
		...
*/
	}
	
...
 
	public static void main(String[] args)
	{
		JFrame frame = new ChessBoard();
		frame.setDefaultCloseOperation( DISPOSE_ON_CLOSE );
		frame.pack();
		frame.setResizable( false );
		frame.setLocationRelativeTo( null );
		frame.setVisible(true);
        }
}

It doesn't surprise me, that you can't see the Figures - you haven't at any point connected the Pictures with them!
The Line[CODE=java]WhiteFigures.pu t("pw.png" + i, whiteFigure[i]);[/CODE]only means, that you can call your (virtual) Figure by using[CODE=java]WhiteFigures.ge t("pw.png1"); // If i == 1[/CODE]Anyway, you do create a chessboard, but you use the same JLabel piece again and again. (OK, that's commented out.) I would suggest, you use an Array of JLabels instead.[CODE=java]JLabel [][] piece = new JLabel[8][8]; // This will give you an 8x8 Array of JLabels[/CODE]Also you can (if you choose to do so) add a picture (or two, if you have the Fields Background in the same picture) to your Figures. Of course, you'd have to give them a way of setting the images and a getImage method, which returns the correct Image. (You could either have them calculate, if they are on a black or a white field, or you calculate that somewhere else and tell the Figure, which picture you want.)

Two last tips (for now):
1. If you use [CODE=java] instead of [CODE] in this Forum, it will be formated even better.
2. Please post all classes. (Figures.java, Pawn.java and King.java plus any other classes that you may have) It will make life so much easier for anyone who wants to help you.

Chess program

Chess program

Comment

Comment

Comment

Comment

Comment

Comment

Comment