/*******************************/
/* NimCalculator.java          */
/* Glenn A. Richard            */
/* November 13, 2000           */
/* Glenn.Richard@sunysb.edu    */
/*******************************/
import javax.swing.*;
import java.awt.*;
import java.awt.event.*;
public class NimCalculator extends JPanel implements ActionListener {
    private JLabel titleLabel;
    private JTextField decimalField[];
    private JLabel binaryPlaceLabel[];
    private JTextField binaryField[][];
    private JButton decrementButton[];
    private JTextField nimSumField[];
    private JLabel decimalLabel;
    private JLabel binaryLabel;
    private JLabel nimSumLabel;
    private int count[] = {11, 9, 7};

    public NimCalculator() {
    // constructor
        GridBagLayout gbl;
        GridBagConstraints gbc;
        gbl = new GridBagLayout();
        gbc = new GridBagConstraints();
        setLayout(gbl);
        setBackground(new Color(255, 255, 214));
        Font font;
        int binaryPlace;

        // set up screen components
        titleLabel = new JLabel("Nim Sum Calculator");
        font = titleLabel.getFont().deriveFont(Font.BOLD);
        buildConstraints(gbc, 0, 0, 10, 1, 100, 100, GridBagConstraints.NONE, GridBagConstraints.CENTER);
        gbl.setConstraints(titleLabel, gbc);
        titleLabel.setForeground(Color.black);
        add(titleLabel);

        decimalLabel = new JLabel("Decimal");
        buildConstraints(gbc, 0, 1, 1, 1, 100, 100, GridBagConstraints.NONE, GridBagConstraints.CENTER);
        gbl.setConstraints(decimalLabel, gbc);
        decimalLabel.setForeground(Color.red);
        add(decimalLabel);

        binaryLabel = new JLabel("Binary");
        buildConstraints(gbc, 1, 1, 8, 1, 100, 100, GridBagConstraints.NONE, GridBagConstraints.CENTER);
        gbl.setConstraints(binaryLabel, gbc);
        binaryLabel.setForeground(Color.blue);
        add(binaryLabel);

        binaryPlaceLabel = new JLabel[8];
        binaryPlace = 1;
        for (int i = 7; i >= 0; i--) {
            binaryPlaceLabel[i] = new JLabel("" + binaryPlace);
            buildConstraints(gbc, i + 1, 2, 1, 1, 100, 100, GridBagConstraints.NONE, GridBagConstraints.CENTER);
            gbl.setConstraints(binaryPlaceLabel[i], gbc);
            binaryPlaceLabel[i].setForeground(Color.blue);
            add(binaryPlaceLabel[i]);
            binaryPlace *= 2;
        }

        nimSumLabel = new JLabel("Nim Sum");
        buildConstraints(gbc, 0, 6, 1, 1, 100, 100, GridBagConstraints.NONE, GridBagConstraints.CENTER);
        gbl.setConstraints(nimSumLabel, gbc);
        nimSumLabel.setForeground(Color.black);
        add(nimSumLabel);


        decimalField = new JTextField[3];
        binaryField = new JTextField[3][8];
        decrementButton = new JButton[3];
        nimSumField = new JTextField[8];
        for (int i = 0; i < 3; i++) {
            decimalField[i] = new JTextField(4);
            decimalField[i].addActionListener(this);
            buildConstraints(gbc, 0, i + 3, 1, 1, 100, 100, GridBagConstraints.NONE, GridBagConstraints.CENTER);
            gbl.setConstraints(decimalField[i], gbc);
            decimalField[i].setFont(font);
            decimalField[i].setForeground(Color.red);
            decimalField[i].setHorizontalAlignment(SwingConstants.RIGHT);

            add(decimalField[i]);
            for (int j = 0; j < 8; j++) {
                binaryField[i][j] = new JTextField(2);
                binaryField[i][j].addActionListener(this);
                buildConstraints(gbc, j + 1, i + 3, 1, 1, 100, 100, GridBagConstraints.NONE, GridBagConstraints.CENTER);
                gbl.setConstraints(binaryField[i][j], gbc);
                binaryField[i][j].setFont(font);
                binaryField[i][j].setForeground(Color.blue);
                binaryField[i][j].setHorizontalAlignment(SwingConstants.RIGHT);
                add(binaryField[i][j]);
            }
            decrementButton[i] = new JButton("Subtract 1");
            decrementButton[i].addActionListener(this);
            buildConstraints(gbc, 9, i + 3, 1, 1, 100, 100, GridBagConstraints.NONE, GridBagConstraints.CENTER);
            gbl.setConstraints(decrementButton[i], gbc);
            decrementButton[i].setForeground(Color.black);
            
            add(decrementButton[i]);


        }

        for (int i = 0; i < 8; i++) {
            nimSumField[i] = new JTextField(2);
            buildConstraints(gbc, i + 1, 6, 1, 1, 100, 100, GridBagConstraints.NONE, GridBagConstraints.CENTER);
            gbl.setConstraints(nimSumField[i], gbc);
            nimSumField[i].setFont(font);
            nimSumField[i].setForeground(Color.black);
            nimSumField[i].setHorizontalAlignment(SwingConstants.RIGHT);
            nimSumField[i].setEditable(false);
            nimSumField[i].setForeground(Color.black);
            nimSumField[i].setBackground(Color.white);
            add(nimSumField[i]);
        }
        // place the numerical values in the text fields
        setFields();
    }


    public void actionPerformed(ActionEvent ae) {
    // respond to button clicks and hits of the enter key in text fields
        Object source = ae.getSource();
        for (int i = 0; i < 3; i++) {
            if (source == decrementButton[i]) {
                if (count[i] > 0)
                    count[i]--;
                setFields();
                return;
            }
            if (source == decimalField[i]) {
                try {
                    count[i] = Integer.parseInt(decimalField[i].getText());
                }
                catch (NumberFormatException nfe) {
                    decimalField[i].setText("0");
                    count[i] = Integer.parseInt(decimalField[i].getText());
                }
                if (count[i] < 0)
                    count[i] = 0;
                else if (count[i] > 255)
                    count[i] = 255;
                setFields();
                return;
            }
            for (int j = 0; j < 8; j++)
                if (source == binaryField[i][j]) {
                    int binaryDigit;
                    int sum = 0;
                    try {
                        binaryDigit = Integer.parseInt(binaryField[i][j].getText());
                    }
                    catch (NumberFormatException nfe) {
                        binaryField[i][j].setText("0");
                        binaryDigit = Integer.parseInt(binaryField[i][j].getText());
                    }
                    if (binaryDigit < 0)
                        binaryField[i][j].setText("0");
                    else if (binaryDigit > 1)
                        binaryField[i][j].setText("1");
                    for (int k = 0; k < 8; k++) {
                        sum *= 2;
                        sum += Integer.parseInt(binaryField[i][k].getText()) % 2;
                    }
                    count[i] = sum;
                    setFields();
                    return;
                }
        }
        setFields();
    }

    private void setFields() {
    // set the numerical values in the text fields
        int countWork[];
        int nimSumWork[];
        countWork = new int[3];
        nimSumWork = new int[8];
        for (int i = 0; i < 8; i++)
            nimSumWork[i] = 0;
        for (int i = 0; i < 3; i++) {
            countWork[i] = count[i];
            decimalField[i].setText("" + count[i]);
            for (int j = 0; j < 8; j++) {
                binaryField[i][7 - j].setText("" + countWork[i] % 2);
                nimSumWork[j] += (countWork[i] % 2);
                countWork[i] /= 2;
            }
        }
        for (int i = 0; i < 8; i++) {
            nimSumField[7 - i].setText("" + (nimSumWork[i] % 2));
        }
    }

    private static void buildConstraints(GridBagConstraints gbc, int gx, int gy,
        int gw, int gh, int wx, int wy, int fill, int anchor) {
        // build the constraints for the GridBagLayout
        gbc.gridx = gx;
        gbc.gridy = gy;
        gbc.gridwidth = gw;
        gbc.gridheight = gh;
        gbc.weightx = wx;
        gbc.weighty = wy;
        gbc.fill = fill;
        gbc.anchor = anchor;
    }
}