I don't know what's wrong with this chess game

[steve tang]

Hello.
Sorry if the post is inetiquette because this my first time using the forum.
I am making a 2 player chess game using JButtons. The program is supposed to run as the following:

1. create the chessboard with pieces in it

2. select a button

3. determine where the piece could move and count the amount of legal moves and record the positions

4. color these buttons

5. goes to step 2

you click the button to move between 5 and 6

6. according to the amount and the positions~to determine is you click is a legal move or not

you click the button to move between 5 and 6

7. switch the information of the 2 buttons you clicked before

8. fresh~output the result of the switch

9. switch turns

When a piece is clicked on, the possible legal moves are shown but when the square is clicked on, nothing happens. It is supposed to move the piece to the selected square. I think the problem is that the program cannot get to step 2 to move the pieces. Also, when one of the pieces is clicked on, the following error message appears that I don't understand:


Exception in thread "AWT-EventQueue-1" java.lang.NullPointerException
at Chess.select(Chess.java:957)
at Chess.movePawn(Chess.java:379)
at Chess.actionPerformed(Chess.java:126)
at javax.swing.AbstractButton.fireActionPerformed(AbstractButton.java:18
49)
at javax.swing.AbstractButton$Handler.actionPerformed(AbstractButton.jav
a:2169)
at javax.swing.DefaultButtonModel.fireActionPerformed(DefaultButtonModel
.java:420)
at javax.swing.DefaultButtonModel.setPressed(DefaultButtonModel.java:258
)
at javax.swing.plaf.basic.BasicButtonListener.mouseReleased(BasicButtonL
istener.java:234)
at java.awt.Component.processMouseEvent(Component.java:5488)
at javax.swing.JComponent.processMouseEvent(JComponent.java:3093)
at java.awt.Component.processEvent(Component.java:5253)
at java.awt.Container.processEvent(Container.java:1966)
at java.awt.Component.dispatchEventImpl(Component.java:3955)
at java.awt.Container.dispatchEventImpl(Container.java:2024)
at java.awt.Component.dispatchEvent(Component.java:3803)
at java.awt.LightweightDispatcher.retargetMouseEvent(Container.java:4212
)
at java.awt.LightweightDispatcher.processMouseEvent(Container.java:3892)

at java.awt.LightweightDispatcher.dispatchEvent(Container.java:3822)
at java.awt.Container.dispatchEventImpl(Container.java:2010)
at java.awt.Component.dispatchEvent(Component.java:3803)
at java.awt.EventQueue.dispatchEvent(EventQueue.java:463)
at java.awt.EventDispatchThread.pumpOneEventForHierarchy(EventDispatchTh
read.java:234)
at java.awt.EventDispatchThread.pumpEventsForHierarchy(EventDispatchThre
ad.java:163)
at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:157)

at java.awt.EventDispatchThread.pumpEvents(EventDispatchThread.java:149)

at java.awt.EventDispatchThread.run(EventDispatchThread.java:110)

The code is:

 
//Landy Zhang and Steven Tang
//Chess
import java.awt.*;
import java.awt.event.*;
import java.text.*;
import javax.swing.*;
 
public class Chess extends java.applet.Applet implements MouseListener, ActionListener
{
Color wselect = new Color(255,103,60); //white square color when showing legal move
Color bselect = new Color(157,35,0); //blacks legal move color
Color pselect = new Color(255,203,83); //color of square under piece when clicked on
TextField message;//textfield for giving the user info such as illegal moves
TextField moves;//list of past moves
private Point P[] = new Point[27]; //array storing positions that the selected piece can move (27 is max for queen)
private int p = 0; // p is the number of places the selected piece can move
private JButton newGame = new JButton(); //new game button
private JButton piece[][] = new JButton[8][8]; //64 squares on the board
private int temp[][] = new int[8][8]; //assign values to buttons to test to see what kind of square it is.
// the values of the buttons :white pieces are positive and black pieces are negative, blank squares are 0
private int k1 = 0, k2 = 0, count, turn = 0, step = 2, m, n;
// k1 is x position in piece array; k2 is y position
// if turn=0, it is white's turn, if turn =1, it is black's turn.
// if step =1, the user is selecting a piece.
// if step =2, the user is selecting a square for the piece to move to
// m is k1's temp
// n is k2's temp
 
public void init()
{

message = new TextField("message");
moves = new TextField("the list of moves");
message.setBounds(450,70,250,30);
moves.setBounds(450,150,250,200);
add(message);
add(moves);
message.addActionListener(this);
moves.addActionListener(this);
//new game button 
setLayout(null);
ImageIcon newg = new ImageIcon("images/newgame.gif");
newGame = new JButton(newg);
add(newGame);

newGame.setBounds(450,20,170,30);
newGame.addActionListener(this);
//squares
for (k1 = 0; k1 < 8; k1 ++)
{
for (k2 = 0; k2 < 8; k2 ++)
{
temp[k1][k2] = 0;
    piece[k1][k2] = new JButton();
add(piece[k1][k2]);
piece[k1][k2].setBounds(k2 * 49, k1 * 49, 49, 49);
if (Math.pow(-1, k1 + k2) == 1)
{
piece[k1][k2].setBackground(Color.white);
}
else
{
piece[k1][k2].setBackground(Color.black);
}
piece[k1][k2].addActionListener(this);
}
}
newGame();//set up the default
}
 
public void actionPerformed(ActionEvent ae)
{


if (ae.getSource() instanceof JButton)
{
JButton clickedButton = (JButton) ae.getSource();
if (clickedButton == newGame)
{
newGame();
}
else
{
for (k1 = 0; k1 < 8; k1 ++ )
{
for (k2 = 0; k2 < 8; k2 ++ )
{
if (clickedButton == piece[k1][k2])
{
if (step == 1)
{
if (temp[k1][k2] != 0)
{
if(temp[k1][k2] > 0)
{
if (turn == 1)
{
message.setText("It's black turn.");
}
else
{
message.setText("move the piece.");
piece[k1][k2].setBackground(pselect); 
if (temp[k1][k2] == 1)
{
moveRook(k1, k2);
}
if (temp[k1][k2] == 2)
{
moveKnight(k1, k2);
}
if (temp[k1][k2] == 3)
{
moveBishop(k1, k2);
}
if (temp[k1][k2] == 4)
{
moveQueen(k1, k2);
}
if (temp[k1][k2] == 5)
{
moveKing(k1, k2);
}
if (temp[k1][k2] == 6)
{
movePawn(k1, k2);
}
}
}
else
{
if (turn == 0)
{
message.setText("It's white turn.");
}
else
{
message.setText("move the piece.");
piece[k1][k2].setBackground(pselect); 
if (temp[k1][k2] == -1)
{
moveRook(k1, k2);
}
if (temp[k1][k2] == -2)
{
moveKnight(k1, k2);
}
if (temp[k1][k2] == -3)
{
moveBishop(k1, k2);
}
if (temp[k1][k2] == -4)
{
moveQueen(k1, k2);
}
if (temp[k1][k2] == -5)
{
moveKing(k1, k2);
}
if (temp[k1][k2] == -6)
{
movePawn(k1, k2);
}
}
}
}
else
{
message.setText("choose a white piece.");
}
}
else
{
/**** STEP 2 ****/
step = 1;
for (count = 0; count <= p; count ++ )
{
m = (int)(P[count].getX());
n = (int)(P[count].getY());
if (clickedButton == piece[m][n])
{
temp[m][n] = temp[k1][k2];
temp[k1][k2] = 0;
fresh();
p = 0;
}
else
{
p = 0;
if (Math.pow(-1, k1 + k2) == 1)
{
piece[k1][k2].setBackground(Color.white);
}
else
{
piece[k1][k2].setBackground(Color.black);
}
}
}
}
}
}
}
}
}
}

public void newGame()
{
message.setText("message");
//white rooks
ImageIcon wrook = new ImageIcon("images/wrook.gif");
piece[7][0].setIcon(wrook);
temp[7][0] = 1;
piece[7][7].setIcon(wrook);
temp[7][7] = 1;
//white knights
ImageIcon wknight = new ImageIcon("images/wknight.gif");
piece[7][1].setIcon(wknight);
temp[7][1] = 2;
piece[7][6].setIcon(wknight);
temp[7][6] = 2;
//white bishops
ImageIcon wbishop = new ImageIcon("images/wbishop.gif");
piece[7][2].setIcon(wbishop);
temp[7][2] = 3;
piece[7][5].setIcon(wbishop);
temp[7][5] = 3;
//white queen
ImageIcon wqueen = new ImageIcon("images/wqueen.gif");
piece[7][3].setIcon(wqueen);
temp[7][3] = 4;
//white king
ImageIcon wking = new ImageIcon("images/wking.gif");
piece[7][4].setIcon(wking);
temp[7][4] = 5;
ImageIcon wpawn = new ImageIcon("images/wpawn.gif");
for (count = 0; count <= 7; count ++ )
{
piece[6][count].setIcon(wpawn);
temp[6][count] = 6;
}

//black rooks
ImageIcon brook = new ImageIcon("images/brook.gif");
piece[0][0].setIcon(brook);
temp[0][0] = -1;
piece[0][7].setIcon(brook);
temp[0][7] = -1;
//black knights
ImageIcon bknight = new ImageIcon("images/bknight.gif");
piece[0][1].setIcon(bknight);
temp[0][1] = -2;
piece[0][6].setIcon(bknight);
temp[0][6] = -2;
//black bishops
ImageIcon bbishop = new ImageIcon("images/bbishop.gif");
piece[0][2].setIcon(bbishop);
temp[0][2] = -3;
piece[0][5].setIcon(bbishop);
temp[0][5] = -3;
//black queen
ImageIcon bqueen = new ImageIcon("images/bqueen.gif");
piece[0][3].setIcon(bqueen);
temp[0][3] = -4;
//black king
ImageIcon bking = new ImageIcon("images/bking.gif");
piece[0][4].setIcon(bking);
temp[0][4] = -5;
ImageIcon bpawn = new ImageIcon("images/bpawn.gif");
for (count = 0; count <= 7; count ++ )
{
piece[1][count].setIcon(bpawn);
temp[1][count] = -6;
}

//clear
for (count = 0; count <= 7; count ++ )
{
piece[2][count].setIcon(null);
temp[2][count] = 0;
piece[3][count].setIcon(null);
temp[3][count] = 0;
piece[4][count].setIcon(null);
temp[4][count] = 0;
piece[5][count].setIcon(null);
temp[5][count] = 0;
}

for (k1 = 0; k1 < 8; k1 ++)
{
for (k2 = 0; k2 < 8; k2 ++)
{
if (Math.pow(-1, k1 + k2) == 1)
{
piece[k1][k2].setBackground(Color.white);
}
else
{
piece[k1][k2].setBackground(Color.black);
}
}
}
p = 0;
step = 1;
}
/***STEP 1**/
//moving the pawn
public void movePawn(int k1, int k2)
{
p = 0;
//if it is white's turn
if (turn == 0)
{
if (temp[k1 - 1][k2] == 0) //if the space in front of the pawn is blank, he can move there
{
P[p] = new Point(k1 - 1, k2);
p ++ ;
}
if (k1 == 6) // if the pawns are still on the 2nd line, they can move 2 spaces
{
P[p] = new Point(k1 - 2, k2);
p ++ ;
}
if (k1 > 0 && k2 > 0) //test to see if there is a square on the left and top of the pawn
{
if (temp[k1 - 1][k2 - 1] < 0)// test to see if there is a black piece on top left of pawn
{
P[p] = new Point(k1 - 1, k2 - 1);
p ++ ;
}
}
if (k1 > 0 && k2 < 7)
{
if (temp[k1 - 1][k2 + 1] < 0)//test to see if there is black piece on top right of pawn
{
P[p] = new Point(k1 - 1, k2 + 1);
p ++ ;
}
}
if (k1 == 0)
{
change(k1, k2);
}
}
else
//black pawn moves. The same thing as the white, except the pawns move in the opposite direction.
 
{
if (temp[k1 + 1][k2] == 0)
{
P[p] = new Point(k1 + 1, k2);
p ++ ;
}
if (k1 == 6)
{
P[p] = new Point(k1 + 2, k2);
p ++ ;
}
if (k1 < 7 && k2 > 0)
{
if (temp[k1 + 1][k2 - 1] < 0)
{
P[p] = new Point(k1 + 1, k2 - 1);
p ++ ;
}
}
if (k1 < 7 && k2 < 7)
{
if (temp[k1 + 1][k2 + 1] < 0)
{
P[p] = new Point(k1 + 1, k2 + 1);
p ++ ;
}
}
if (k1 == 7)
{
change(k1, k2);
}
}
select();
}
//make knight move, similar pawn concept
public void moveKnight(int k1, int k2)
{
p = 0;
if (turn==0)
{
if (k1 > 0 && k2 > 1)
{
if (temp[k1 - 1][k2 - 2] <= 0)//see if there is a black piece there.
{
P[p] = new Point(k1 - 1, k2 - 2);
p ++ ;
}
}
if(k1 > 1 && k2 > 0)
{
if (temp[k1 - 2][k2 - 1] <= 0)
{
P[p] = new Point (k1 - 2, k2 - 1);
p ++ ;
}
}
if (k1 < 7 && k2 > 1)
{
if (temp[k1 + 1][k2 - 2] <= 0)//see if there is a black piece there.
{
P[p] = new Point(k1 + 1, k2 - 2);
p ++ ;
}
}
if (k1 < 6 && k2 > 0)
{
if (temp[k1 + 2][k2 - 1] <= 0)//see if there is a black piece there.
{
P[p] = new Point(k1 + 2, k2 - 1);
p ++ ;
}
}
if (k1 > 0 && k2 < 6)
{
if (temp[k1 - 1][k2 + 2] <= 0)//see if there is a black piece there.
{
P[p] = new Point(k1 - 1, k2 + 2);
p ++ ;
}
}
if (k1 > 1 && k2 < 7)
{

if (temp[k1 - 2][k2 + 1] <= 0)//see if there is a black piece there.
{
P[p] = new Point(k1 - 2,k2 + 1);
p ++ ;
}
}
if (k1 < 6 && k2 < 7)
{
if (temp[k1 + 2][k2 + 1] <= 0)//see if there is a black piece there.
{
P[p] = new Point(k1 + 2, k2 + 1);
p ++ ;
}
}
if (k1 < 7 && k2 < 6)
{
if (temp[k1 + 1][k2 + 2] <= 0)//see if there is a black piece there.
{
P[p] = new Point(k1 + 1, k2 + 2);
p ++ ;
}
}
}
else
{
if (k1 > 0 && k2 > 1)
{
if (temp[k1 - 1][k2 - 2] >= 0)//see if there is a black piece there.
{
P[p] = new Point(k1 - 1, k2 - 2);
p ++ ;
}
}
if(k1 > 1 && k2 > 0)
{
if (temp[k1 - 2][k2 - 1] >= 0)
{
P[p] = new Point (k1 - 2, k2 - 1);
p ++ ;
}
}
if (k1 < 7 && k2 > 1)
{
if (temp[k1 + 1][k2 - 2] >= 0)//see if there is a black piece there.
{
P[p] = new Point(k1 + 1, k2 - 2);
p ++ ;
}
}
if (k1 < 6 && k2 > 0)
{
if (temp[k1 + 2][k2 - 1] >= 0)//see if there is a black piece there.
{
P[p] = new Point(k1 + 2, k2 - 1);
p ++ ;
}
}
if (k1 > 0 && k2 < 6)
{
if (temp[k1 - 1][k2 + 2] >= 0)//see if there is a black piece there.
{
P[p] = new Point(k1 - 1, k2 + 2);
p ++ ;
}
}
if (k1 > 1 && k2 < 7)//test other bottom left position
{
if (temp[k1 - 2][k2 + 1] >= 0)//see if there is a black piece there.
{
P[p] = new Point(k1 - 2,k2 + 1);
p ++ ;
}
}
if (k1 < 6 && k2 < 7)//test to see if the knight will go off the bottom right
{
if (temp[k1 + 2][k2 + 1] >= 0)//see if there is a black piece there.
{
P[p] = new Point(k1 + 2, k2 + 1);
p ++ ;
}
}
if (k1 < 7 && k2 < 6)
{
if (temp[k1 + 1][k2 + 2] >= 0)//see if there is a black piece there.
{
P[p] = new Point(k1 + 1, k2 + 2);
p ++ ;
}
}
}
select();
}
// moving the bishop
public void moveBishop(int k1, int k2)
{
p = 0;
if (turn == 0)
{
m = k1 + 1;
n = k2 + 1;
while(m < 8 && n < 8 && temp[m][n] <= 0)
{
P[p] = new Point(m, n);
p ++ ;
m ++ ;
n ++ ;
}
m = k1 - 1;
n = k2 + 1;
while(m >= 0 && n < 8 && temp[m][n] <= 0)
{
P[p] = new Point(m, n);
p ++ ;
m -- ;
n ++ ;
}
m = k1 - 1;
n = k2 - 1;
while(m >= 0 && n >= 0 && temp[m][n] <= 0)
{
P[p] = new Point(m, n);
p ++ ;
m -- ;
n -- ;
}
m = k1 + 1;
n = k2 - 1;
while(m < 8 && n >= 0 && temp[m][n] <= 0)
{
P[p] = new Point(m, n);
p ++ ;
m ++ ;
n -- ;
}
}
else
{
m = k1 + 1;
n = k2 + 1;
while(m < 8 && n < 8 && temp[m][n] >= 0)
{
P[p] = new Point(m, n);
p ++ ;
m ++ ;
n ++ ;
}
m = k1 - 1;
n = k2 + 1;
while(m >= 0 && n < 8 && temp[m][n] >= 0)
{
P[p] = new Point(m, n);
p ++ ;
m -- ;
n ++ ;
}
m = k1 - 1;
n = k2 - 1;
while(m >= 0 && n >= 0 && temp[m][n] >= 0)
{
P[p] = new Point(m, n);
p ++ ;
m -- ;
n -- ;
}
m = k1 + 1;
n = k2 - 1;
while(m < 8 && n >= 0 && temp[m][n] >= 0)
{
P[p] = new Point(m, n);
p ++ ;
m ++ ;
n -- ;
}
}
select();
}
//moving the queen
public void moveQueen(int k1, int k2)
{
p = 0;
if (turn == 0)
{
m = k1 + 1;
n = k2 + 1;
while(m < 8 && n < 8 && temp[m][n] <= 0)
{
P[p] = new Point(m, n);
p ++ ;
m ++ ;
n ++ ;
}
m = k1 - 1;
n = k2 + 1;
while(m >= 0 && n < 8 && temp[m][n] <= 0)
{
P[p] = new Point(m, n);
p ++ ;
m -- ;
n ++ ;
}
m = k1 - 1;
n = k2 - 1;
while(m >= 0 && n >= 0 && temp[m][n] <= 0)
{
P[p] = new Point(m, n);
p ++ ;
m -- ;
n -- ;
}
m = k1 + 1;
n = k2 - 1;
while(m < 8 && n >= 0 && temp[m][n] <= 0)
{
P[p] = new Point(m, n);
p ++ ;
m ++ ;
n -- ;
}
// 
m = k1 + 1;
n = k2;
while(m < 8 && temp[m][n] <= 0)
{
P[p] = new Point(m, n);
p ++ ;
m ++ ;
}
m = k1 - 1;
n = k2;
while(m >= 0 && temp[m][n] <= 0)
{
P[p] = new Point(m, n);
p ++ ;
m -- ;
}
m = k1;
n = k2 - 1;
while(n >= 0 && temp[m][n] <= 0)
{
P[p] = new Point(m, n);
p ++ ;
n -- ;
}
m = k1;
n = k2 + 1;
while(n >= 0 && temp[m][n] <= 0)
{
P[p] = new Point(m, n);
p ++ ;
n ++ ;
}
}
else
{
m = k1 + 1;
n = k2 + 1;
while(m < 8 && n < 8 && temp[m][n] >= 0)
{
P[p] = new Point(m, n);
p ++ ;
m ++ ;
n ++ ;
}
m = k1 - 1;
n = k2 + 1;
while(m >= 0 && n < 8 && temp[m][n] >= 0)
{
P[p] = new Point(m, n);
p ++ ;
m -- ;
n ++ ;
}
m = k1 - 1;
n = k2 - 1;
while(m >= 0 && n >= 0 && temp[m][n] >= 0)
{
P[p] = new Point(m, n);
p ++ ;
m -- ;
n -- ;
}
m = k1 + 1;
n = k2 - 1;
while(m < 8 && n >= 0 && temp[m][n] >= 0)
{
P[p] = new Point(m, n);
p ++ ;
m ++ ;
n -- ;
}
m = k1 + 1;
n = k2;
while(m < 8 && temp[m][n] >= 0)
{
P[p] = new Point(m, n);
p ++ ;
m ++ ;
}
m = k1 - 1;
n = k2;
while(m >= 0 && temp[m][n] >= 0)
{
P[p] = new Point(m, n);
p ++ ;
m -- ;
}
m = k1;
n = k2 - 1;
while(n >= 0 && temp[m][n] >= 0)
{
P[p] = new Point(m, n);
p ++ ;
n -- ;
}
m = k1;
n = k2 + 1;
while(n >= 0 && temp[m][n] >= 0)
{
P[p] = new Point(m, n);
p ++ ;
n ++ ;
}
}
select();
}
//moving the king
public void moveKing(int k1, int k2)
{
p = 0;
if (turn == 0)
{
if (k1 > 0 && k2 > 0)
{
if (temp[k1 - 1][k2 - 1] <= 0)
{
P[p] = new Point(k1 - 1, k2 - 1);
p ++ ;
}
if (temp[k1][k2 - 1] <= 0)
{
P[p] = new Point(k1, k2 - 1);
p ++ ;
}
if (temp[k1 - 1][k2] <= 0)
{
P[p] = new Point(k1 - 1, k2);
p ++ ;
}
}
if (k1 < 7 && k2 > 0)
{
if (temp[k1 + 1][k2] <= 0)
{
P[p] = new Point(k1 + 1, k2);
p ++ ;
}
if (temp[k1 + 1][k2 - 1] <= 0)
{
P[p] = new Point(k1 + 1, k2 - 1);
p ++ ;
}
}
if (k1 < 7 && k2 < 7)
{
if (temp[k1 + 1][k2 + 1] <= 0)
{
P[p] = new Point(k1 + 1, k2 + 1);
p ++ ;
}
if (temp[k1][k2 + 1] <= 0)
{
P[p] = new Point(k1, k2 + 1);
p ++ ;
}
}
if (k1 > 0 && k2 < 7)
{
if (temp[k1 - 1][k2 + 1] <= 0)
{
P[p] = new Point(k1 - 1, k2 + 1);
p ++ ;
}
}
}
else
{
if (k1 > 0 && k2 > 0)
{
if (temp[k1 - 1][k2 - 1] >= 0)
{
P[p] = new Point(k1 - 1, k2 - 1);
p ++ ;
}
if (temp[k1][k2 - 1] >= 0)
{
P[p] = new Point(k1, k2 - 1);
p ++ ;
}
if (temp[k1 - 1][k2] >= 0)
{
P[p] = new Point(k1 - 1, k2);
p ++ ;
}
}
if (k1 < 7 && k2 > 0)
{
if (temp[k1 + 1][k2] >= 0)
{
P[p] = new Point(k1 + 1, k2);
p ++ ;
}
if (temp[k1 + 1][k2 - 1] >= 0)
{
P[p] = new Point(k1 + 1, k2 - 1);
p ++ ;
}
}
if (k1 < 7 && k2 < 7)
{
if (temp[k1 + 1][k2 + 1] >= 0)
{
P[p] = new Point(k1 + 1, k2 + 1);
p ++ ;
}
if (temp[k1][k2 + 1] >= 0)
{
P[p] = new Point(k1, k2 + 1);
p ++ ;
}
}
if (k1 > 0 && k2 < 7)
{
if (temp[k1 - 1][k2 + 1] >= 0)
{
P[p] = new Point(k1 - 1, k2 + 1);
p ++ ;
}
}
}
select();
}
//moving the rook
public void moveRook(int k1, int k2)
{
p = 0;
if (turn == 0)
{
m = k1 + 1;
n = k2;
while(m < 8 && temp[m][n] <= 0)
{
P[p] = new Point(m, n);
p ++ ;
m ++ ;
}
m = k1 - 1;
n = k2;
while(m >= 0 && temp[m][n] <= 0)
{
P[p] = new Point(m, n);
p ++ ;
m -- ;
}
m = k1;
n = k2 - 1;
while(n >= 0 && temp[m][n] <= 0)
{
P[p] = new Point(m, n);
p ++ ;
n -- ;
}
m = k1;
n = k2 + 1;
while(n >= 0 && temp[m][n] <= 0)
{
P[p] = new Point(m, n);
p ++ ;
n ++ ;
}
}
else
{
m = k1 + 1;
n = k2;
while(m < 8 && temp[m][n] >= 0)
{
P[p] = new Point(m, n);
p ++ ;
m ++ ;
}
m = k1 - 1;
n = k2;
while(m >= 0 && temp[m][n] >= 0)
{
P[p] = new Point(m, n);
p ++ ;
m -- ;
}
m = k1;
n = k2 - 1;
while(n >= 0 && temp[m][n] >= 0)
{
P[p] = new Point(m, n);
p ++ ;
n -- ;
}
m = k1;
n = k2 + 1;
while(n >= 0 && temp[m][n] >= 0)
{
P[p] = new Point(m, n);
p ++ ;
n ++ ;
}
}
select();
}

public void change(int k1, int k2)
{

}

public void select()
{
for (count = 0; count <= p; count ++ )
{
m = (int)(P[count].getX());
n = (int)(P[count].getY());
if (Math.pow(-1, m + n) == 1)
{
piece[m][n].setBackground(wselect);
}
else
{
piece[m][n].setBackground(bselect);
}
}
step = 2;
}
 

public void fresh()
{
//after completion of step 2 change, refresh screen and change pictures
ImageIcon wking = new ImageIcon("images/wking.gif");
ImageIcon bking = new ImageIcon("images/bking.gif");
ImageIcon wpawn = new ImageIcon("images/wpawn.gif");
ImageIcon bpawn = new ImageIcon("images/bpawn.gif");
ImageIcon wqueen = new ImageIcon("images/wqueen.gif");
ImageIcon bqueen = new ImageIcon("images/bqueen.gif");
ImageIcon wbishop = new ImageIcon("images/wbishop.gif");
ImageIcon bbishop = new ImageIcon("images/bbishop.gif");
ImageIcon wknight = new ImageIcon("images/wknight.gif");
ImageIcon bknight = new ImageIcon("images/bknight.gif");
ImageIcon wrook = new ImageIcon("images/wrook.gif");
ImageIcon brook = new ImageIcon("images/brook.gif");
for (k1 = 0; k1 < 8; k1 ++)
{
for (k2 = 0; k2 < 8; k2 ++)
{
if (temp[k1][k2] == 0)
{
piece[k1][k2].setIcon(null);
}
if (temp[k1][k2] == 1)
{
piece[k1][k2].setIcon(wrook);
}
if (temp[k1][k2] == 2)
{
piece[k1][k2].setIcon(wknight);
}
if (temp[k1][k2] == 3)
{
piece[k1][k2].setIcon(wbishop);
}
if (temp[k1][k2] == 4)
{
piece[k1][k2].setIcon(wqueen);
}
if (temp[k1][k2] == 5)
{
piece[k1][k2].setIcon(wking);
}
if (temp[k1][k2] == 6)
{
piece[k1][k2].setIcon(wpawn);
}
if (temp[k1][k2] == -1)
{
piece[k1][k2].setIcon(brook);
}
if (temp[k1][k2] == -2)
{
piece[k1][k2].setIcon(bknight);
}
if (temp[k1][k2] == -3)
{
piece[k1][k2].setIcon(bbishop);
}
if (temp[k1][k2] == -4)
{
piece[k1][k2].setIcon(bqueen);
}
if (temp[k1][k2] == -5)
{
piece[k1][k2].setIcon(bking);
}
if (temp[k1][k2] == -6)
{
piece[k1][k2].setIcon(bpawn);
}
if (Math.pow(-1, k1 + k2) == 1)
{
piece[k1][k2].setBackground(Color.white);
}
else
{
piece[k1][k2].setBackground(Color.black);
}
}
}
turn %= turn + 1;
p = 0;
}

public void mouseClicked(MouseEvent me)
{
}

public void mouseEntered(MouseEvent me)
{
}

public void mouseExited(MouseEvent me)
{
}

public void mousePressed(MouseEvent me)
{
}

public void mouseReleased(MouseEvent me)
{
}

} 

[Svend Rost]

Hi, and welcome to the Javaranch.

You need to focus on these lines:

at Chess.select(Chess.java:957)
at Chess.movePawn(Chess.java:379)
at Chess.actionPerformed(Chess.java:126)

Your getting a nullpointer exception - in other words, your trying to call
a method, draw ect. something that isn't initialised. Take a look at line
957,379 and 126 in your Chess class. You might wan't to try to "System.out.println("do I exist in memory? "+ object)" to find out if some of your objects doesn't exist.

Feel free to reply if your still having problems.. but please don't make me read 1000 lines of code