0
package newsatranc;


    import java.awt.BorderLayout;
    import java.awt.Color;
    import java.awt.ComponentOrientation;
    import java.awt.Cursor;
    import java.awt.GridLayout;
    import java.awt.event.InputEvent;
    import java.awt.image.BufferedImage;
    import java.io.IOException;
    import java.io.InputStream;
    import java.util.Map;
    import java.util.TreeMap;

    import javax.imageio.ImageIO;
    import javax.swing.ImageIcon;
    import javax.swing.JButton;
    import javax.swing.JFrame;
    import javax.swing.JLabel;
    import javax.swing.JOptionPane;
    import javax.swing.JPanel;
    import javax.swing.JToolBar;
    import java.awt.Dimension;

    public class NewSatranc extends JFrame {

            private static final long serialVersionUID = 1L;

            private JPanel jContentPane = null;

            private JPanel jPanel = null;

            private JToolBar tlbMain = null;

            private JLabel lblCells[] = new JLabel[64];

            private String jPieces[][] = new String[8][8];  //  @jve:decl-index=0:

            private JButton btnNewGame = null;

            private JLabel lblStatus = null;

            private int heldX, heldY, heldI = -1;

            // Map the full names of the pieces to their codenames (wRook, wQueen, etc.)
            private Map pieceName = new TreeMap();  //  @jve:decl-index=0:

            private JLabel lblCurrPlayer = null;

            // Stores the current player's move - we can easily match it against
            // the first character of the pieces array
            private char currPlayer = ' ';

            private JButton btnUndo = null;

            private int[][] moves = new int[10][6];

            private String movedPieces[] = new String[10];

            private int currMove = 0;

            /**
             * This is the default constructor
             */
            public NewSatranc() {
                    super();
                    initialize();
                    buildBoard();
            }

            /**
             * This method initializes btnUndo     
             *      
             * @return javax.swing.JButton
             */
            private JButton getBtnUndo() {
                    if (btnUndo == null) {
                            btnUndo = new JButton();
                            btnUndo.setText("Undo");
                            btnUndo.setEnabled(false);
                            btnUndo.addMouseListener(new java.awt.event.MouseAdapter() {
                                    public void mouseReleased(java.awt.event.MouseEvent e) {
                                            undoMove();
                                    }
                            });
                    }
                    return btnUndo;
            }

            public static void main( String args[] ) {
                    new NewSatranc().setVisible(true);
            }

            /**
             * This method initializes this
             *
             * @return void
             */
            private void initialize() {
                    this.setSize(671, 555);
                    this.setContentPane(getJContentPane());
                    this.setTitle("Basic Chess");
                    this.setExtendedState(JFrame.MAXIMIZED_BOTH);
            }

            /**
             * This method initializes jContentPane
             *
             * @return javax.swing.JPanel
             */
            private JPanel getJContentPane() {
                    if (jContentPane == null) {
                            jContentPane = new JPanel();
                            jContentPane.setLayout(new BorderLayout());
                            jContentPane.add(getJPanel(), BorderLayout.CENTER);
                            jContentPane.add(getTlbMain(), BorderLayout.NORTH);
                    }
                    return jContentPane;
            }

            /**
             * This method initializes jPanel       
             *      
             * @return javax.swing.JPanel   
             */
            private JPanel getJPanel() {
                    if (jPanel == null) {
                            GridLayout gridLayout = new GridLayout();
                            gridLayout.setRows(8);
                            gridLayout.setHgap(5);
                            gridLayout.setVgap(5);
                            gridLayout.setColumns(8);
                            jPanel = new JPanel();
                            jPanel.setLayout(gridLayout);
                            //buildBoard();
                    }
                    return jPanel;
            }

            private void newGame()
            {
                    resetBoard();
                    resetPieces();
            }

            private void resetPieces()
            {
                    jPieces = new String[8][8];
                    jPieces[0][0] = "bRook";
                    jPieces[0][1] = "bKnight";
                    jPieces[0][2] = "bBishop";
                    jPieces[0][3] = "bKing";
                    jPieces[0][4] = "bQueen";
                    jPieces[0][5] = "bBishop";
                    jPieces[0][6] = "bKnight";
                    jPieces[0][7] = "bRook";
                    jPieces[1][0] = "bPawn";
                    jPieces[1][1] = "bPawn";
                    jPieces[1][2] = "bPawn";
                    jPieces[1][3] = "bPawn";
                    jPieces[1][4] = "bPawn";
                    jPieces[1][5] = "bPawn";
                    jPieces[1][6] = "bPawn";
                    jPieces[1][7] = "bPawn";

                    jPieces[6][0] = "wPawn";
                    jPieces[6][1] = "wPawn";
                    jPieces[6][2] = "wPawn";
                    jPieces[6][3] = "wPawn";
                    jPieces[6][4] = "wPawn";
                    jPieces[6][5] = "wPawn";
                    jPieces[6][6] = "wPawn";
                    jPieces[6][7] = "wPawn";
                    jPieces[7][0] = "wRook";
                    jPieces[7][1] = "wKnight";
                    jPieces[7][2] = "wBishop";
                    jPieces[7][3] = "wKing";
                    jPieces[7][4] = "wQueen";
                    jPieces[7][5] = "wBishop";
                    jPieces[7][6] = "wKnight";
                    jPieces[7][7] = "wRook";
                    RepaintPieces();
            }

            private void PaintPiece(String pieceName, int i)
            {
                    try
                    {
                            if(pieceName != null && pieceName != "")
                            {
                                    InputStream inIcon = ClassLoader.getSystemResourceAsStream("pociu/games/chess/" + pieceName + ".png");
                                    BufferedImage imgIcon = ImageIO.read(inIcon);
                                    lblCells[i].setIcon(new ImageIcon(imgIcon));
                                    //System.out.println("Painted " + pieceName + " at " + i);
                            }
                            else
                            {
                                    lblCells[i].setIcon(null);
                                    //System.out.println("Cleared cell at " + i);
                            }
                    }
                    catch(IOException e)
                    {
                            e.printStackTrace();
                    }
            }

            private void RepaintPieces()
            {
                    int i = 0;
                    for(int x = 0; x < 8; x++)
                    {
                            for(int y = 0; y < 8; y++)
                            {
                                    if(jPieces[x][y] != null && !jPieces[x][y].equals(""))
                                    {
                                            PaintPiece(jPieces[x][y], i);
                                    }
                                    else
                                    {
                                            PaintPiece("", i);
                                    }
                                    i++;
                            }
                    }
            }

            private void ClearHlight(int i, int rowNum)
            {
                    if((i + rowNum) % 2 == 0)
                    {
                            lblCells[i].setBackground(Color.WHITE);
                    }
                    else
                    {
                            lblCells[i].setBackground(Color.GRAY);
                    }
            }

            private void undoMove()
            {
                    if(btnUndo.isEnabled() && currMove > 0)
                    {
                            currMove--;
                            movePiece(moves[currMove][3], moves[currMove][4], moves[currMove][5], moves[currMove][0], moves[currMove][1], moves[currMove][2], true);
                    }
            }

            private void resetBoard()
            {
                    currMove = 0;
                    pieceName.clear();
                    pieceName.put("bRook", "Black Rook");
                    pieceName.put("bQueen", "Black Queen");
                    pieceName.put("bPawn", "Black Pawn");
                    pieceName.put("bKnight", "Black Knight");
                    pieceName.put("bBishop", "Black Bishop");
                    pieceName.put("bKing", "Black King");
                    pieceName.put("wRook", "White Rook");
                    pieceName.put("wQueen", "White Queen");
                    pieceName.put("wPawn", "White Pawn");
                    pieceName.put("wKnight", "White Knight");
                    pieceName.put("wBishop", "White Bishop");
                    pieceName.put("wKing", "White King");
                    pieceName.put("wRook", "White Rook");

                    // If we're holding a piece, clear the hover of the cell
                    if(heldI >= 0 && heldX >= 0)
                    {
                            ClearHlight(heldI, heldX);
                    }

                    switchPlayer();

                    heldX = heldY = heldI = -1;
            }

            private void buildBoard()
            {
                    // First reset the variables, maps, etc.
                    resetBoard();

                    int rowColor = 0;
                    int i = 0;
                    for(int x = 0; x <= 7; x++)
                    {
                            rowColor++;
                            for(int y = 0; y <= 7; y++)
                            {
                                    lblCells[i] = new JLabel("", JLabel.CENTER);
                                    lblCells[i].setOpaque(true);
                                    if(rowColor % 2 == 0)
                                    {
                                            lblCells[i].setBackground(Color.GRAY);
                                    }
                                    else
                                    {
                                            lblCells[i].setBackground(Color.WHITE);
                                    }

                                    final int passX = x;
                                    final int passY = y;
                                    final int passI = i;

                                    lblCells[i].addMouseListener(new java.awt.event.MouseAdapter() {
                                            public void mouseEntered(java.awt.event.MouseEvent e) {
                                                    // If we're holding a piece show that along with the cell we're hovering
                                                    if(heldI > 0)
                                                    {
                                                            lblStatus.setText("Picked up " + pieceName.get(jPieces[heldX][heldY]) + " at " + showBoardRelative(heldX, heldY) + " | Hovering: " + showBoardRelative(passX, passY));
                                                    }
                                                    else // Just show what we're hovering
                                                    {
                                                            lblStatus.setText("Hovering: " + showBoardRelative(passX, passY));
                                                    }
                                                    // Unless we hover the one we're holding...
                                                    if(passI != heldI)
                                                    {
                                                            lblCells[passI].setBackground(Color.DARK_GRAY);
                                                    }
                                            }
                                    });

                                    lblCells[i].addMouseListener(new java.awt.event.MouseAdapter() {
                                            public void mouseExited(java.awt.event.MouseEvent e) {
                                                    lblStatus.setText("");
                                                    // Unless we hover the one we're holding...
                                                    if(passI != heldI)
                                                    {
                                                            // Clear the hover effect
                                                            ClearHlight(passI, passX);
                                                    }
                                            }
                                    });

                                    lblCells[i].addMouseListener(new java.awt.event.MouseAdapter() {
                                            public void mouseReleased(java.awt.event.MouseEvent e) {
                                                    if(e.getModifiers() == InputEvent.BUTTON3_MASK)
                                                    {
                                                            showCellInfo(passX, passY, passI);
                                                    }
                                                    else if(e.getModifiers() == InputEvent.BUTTON1_MASK)
                                                    {
                                                            clickCell(e, passX, passY, passI);
                                                    }
                                            }
                                    });

                                    jPanel.add(lblCells[i]);
                                    rowColor++;
                                    i++;
                            }
                    }
                    resetPieces();
            }

            // Translates grid relative coordinates to chess board relative
            // For ex.: 0x0 to 8A
            private String showBoardRelative(int x, int y)
            {
                    String chessCoord = "";
                    chessCoord = (x - 8) * -1 + "" + (char)(y + 65);
                    return chessCoord;
            }

            private void showCellInfo(int x, int y, int i)
            {
                    if(jPieces[x][y] != null && !jPieces[x][y].equals(""))
                    {
                            JOptionPane.showMessageDialog( null, pieceName.get(jPieces[x][y]) + " located at " + showBoardRelative(x, y), "Cell Information", JOptionPane.INFORMATION_MESSAGE );
                    }
                    else
                    {
                            JOptionPane.showMessageDialog( null, "No piece located at " + showBoardRelative(x, y), "Cell Information", JOptionPane.INFORMATION_MESSAGE );
                    }
            }

            private boolean isValidMove(int fromX, int fromY)
            {
                    if(jPieces[fromX][fromY].length() > 0 && jPieces[fromX][fromY].charAt(0) == currPlayer)
                    {
                            return true;                   
                    }
                    else
                    {
                            return false;
                    }
            }

            private void movePiece(int fromX, int fromY, int fromI, int toX, int toY, int toI, boolean isUndo)
            {
                    if(fromX == toX && fromY == toY)
                    {
                            ClearHlight(fromI, fromX);
                            lblStatus.setText("Move canceled.");
                    }
                    else if(isValidMove(fromX, fromY) || isUndo == true)
                    {
                            PaintPiece(jPieces[fromX][fromY], toI);
                            PaintPiece("", fromI);
                            ClearHlight(fromI, fromX);
                            lblStatus.setText("Moved " + pieceName.get(jPieces[fromX][fromY]) + " from " + showBoardRelative(fromX, fromY) + " to " + showBoardRelative(toX, toY));
                            jPieces[toX][toY] = jPieces[fromX][fromY];
                            jPieces[fromX][fromY] = "";
                            if(currMove > 9)
                            {
                                    pushbackUndos();
                            }
                            moves[currMove] = new int[6];
                            moves[currMove][0] = fromX;
                            moves[currMove][1] = fromY;
                            moves[currMove][2] = fromI;
                            moves[currMove][3] = toX;
                            moves[currMove][4] = toY;
                            moves[currMove][5] = toI;
                            movedPieces[currMove] = jPieces[fromX][fromY];
                            btnUndo.setEnabled(true);
                            if(isUndo == false)
                            {
                                    currMove++;
                            }
                            switchPlayer();
                    }
                    else
                    {
                            ClearHlight(fromI, fromX);
                            JOptionPane.showMessageDialog( null, "It's the " + lblCurrPlayer.getText(), "Illegal Move", JOptionPane.INFORMATION_MESSAGE );
                    }
            }

            private void pushbackUndos()
            {
                    for(int i = 0; i < 9; i++)
                    {
                            moves[i] = moves[i + 1];
                            movedPieces[i] = movedPieces[i + 1];
                    }
                    currMove--;
            }

            private void switchPlayer()
            {
                    //System.out.write(currPlayer);
                    if(currPlayer == 'w')
                    {
                            currPlayer = 'b';
                            lblCurrPlayer.setText("Black Player's Turn.");
                            lblCurrPlayer.setBackground(Color.BLACK);
                            lblCurrPlayer.setForeground(Color.WHITE);
                    }
                    else if(currPlayer == 'b' || currPlayer == ' ')
                    {
                            currPlayer = 'w';
                            lblCurrPlayer.setText("White Player's Turn.");
                            lblCurrPlayer.setBackground(Color.WHITE);
                            lblCurrPlayer.setForeground(Color.BLACK);
                    }
            }

            private void clickCell(java.awt.event.MouseEvent e, int x, int y, int i)
            {
                    JLabel lblClicked = (JLabel)e.getSource();
                    if(heldI != -1) // We're dropping a piece
                    {
                            jContentPane.setCursor(Cursor.getPredefinedCursor(Cursor.DEFAULT_CURSOR));
                            movePiece(heldX, heldY, heldI, x, y, i, false);
                            heldX = heldY = heldI = -1;
                    }
                    else // We're picking up a piece
                    {
                            if(jPieces[x][y] == null || jPieces[x][y].equals(""))
                            {
                                    lblStatus.setText("No piece to pick up.");
                            }
                            else
                            {
                                    jContentPane.setCursor(Cursor.getPredefinedCursor(Cursor.HAND_CURSOR));
                                    lblClicked.setBackground(new Color(255, 176, 70));
                                    lblStatus.setText("Picked up " + pieceName.get(jPieces[x][y]) + " from " + showBoardRelative(x, y));
                                    heldX = x;
                                    heldY = y;
                                    heldI = i;
                            }
                    }
            }

            /**
             * This method initializes tlbMain     
             *      
             * @return javax.swing.JToolBar
             */
            private JToolBar getTlbMain() {
                    if (tlbMain == null) {
                            lblCurrPlayer = new JLabel();
                            lblCurrPlayer.setText("");
                            lblCurrPlayer.setOpaque(true);
                            lblStatus = new JLabel();
                            lblStatus.setText("");
                            lblStatus.setPreferredSize(new Dimension(200, 16));
                            lblStatus.setSize(new Dimension(200, 16));
                            tlbMain = new JToolBar();
                            tlbMain.setOrientation(JToolBar.HORIZONTAL);
                            tlbMain.setComponentOrientation(ComponentOrientation.LEFT_TO_RIGHT);
                            tlbMain.setFloatable(false);
                            tlbMain.add(getBtnNewGame());
                            tlbMain.add(new JToolBar.Separator());
                            tlbMain.add(getBtnUndo());
                            tlbMain.add(new JToolBar.Separator());
                            tlbMain.add(lblCurrPlayer);
                            tlbMain.add(new JToolBar.Separator());
                            tlbMain.add(lblStatus);
                    }
                    return tlbMain;
            }

            /**
             * This method initializes btnNewGame   
             *      
             * @return javax.swing.JButton
             */
            private JButton getBtnNewGame() {
                    if (btnNewGame == null) {
                            btnNewGame = new JButton();
                            btnNewGame.setText("New Game");
                            btnNewGame.addMouseListener(new java.awt.event.MouseAdapter() {
                                    public void mouseReleased(java.awt.event.MouseEvent e) {
                                            if(JOptionPane.YES_OPTION == JOptionPane.showConfirmDialog(null, "Are you sure you wish to end this game?"))
                                            {
                                                    newGame();
                                            }
                                    }
                            });
                    }
                    return btnNewGame;
            }

    }

This is the error message:

Exception in thread "main" java.lang.IllegalArgumentException: input == null!
    at javax.imageio.ImageIO.read(ImageIO.java:1348)
    at newsatranc.NewSatranc.PaintPiece(NewSatranc.java:200)
    at newsatranc.NewSatranc.RepaintPieces(NewSatranc.java:225)
    at newsatranc.NewSatranc.resetPieces(NewSatranc.java:190)
    at newsatranc.NewSatranc.buildBoard(NewSatranc.java:362)
    at newsatranc.NewSatranc.<init>(NewSatranc.java:76)
    at newsatranc.NewSatranc.main(NewSatranc.java:99)

What is wwrong with my code ?

2
Contributors
1
Reply
3
Views
4 Years
Discussion Span
Last Post by NormR1
1

Exception in thread "main" java.lang.IllegalArgumentException: input == null!
at javax.imageio.ImageIO.read(ImageIO.java:1348)
at newsatranc.NewSatranc.PaintPiece(NewSatranc.java:200)

At line 200 the code called the ImageIO read() method with a null value. Find the variable on line 200 and backtrack in the code to see why it does not have a valid non-null value.

This topic has been dead for over six months. Start a new discussion instead.
Have something to contribute to this discussion? Please be thoughtful, detailed and courteous, and be sure to adhere to our posting rules.