// CSE 143, Winter 2009, Marty Stepp
//
// Stuart Reges
// 2/6/04
// slightly modified by Marty Stepp, Feb 12 2009
//
// This is a variation of the 8 queens board class that provides an animation
// of the recursive backtracking.

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

public class GraphicalBoard extends Board implements ChangeListener {
    private JButton[][] buttons;

    public GraphicalBoard(int size) {
        super(size);
        JFrame f = new JFrame();
        f.setSize(60 * size + 50, 60 * size + 80);
        f.setTitle("Eight Queens");
        f.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        // add buttons in the middle for the chess squares
        JPanel center = new JPanel(new GridLayout(size, size, 1, 1));
        f.add(center);
        center.setBackground(Color.black);
        buttons = new JButton[size][size];
        Font font24 = new Font("SansSerif", Font.BOLD, 24);
        for (int i = 0; i < size; i++) {
            for (int j = 0; j < size; j++) {
                JButton button = new JButton();
                button.setBackground((i + j) % 2 == 0 ? Color.WHITE : Color.BLACK);
                button.setForeground((i + j) % 2 == 1 ? Color.WHITE : Color.BLACK);
                button.setFont(font24);
                buttons[i][j] = button;
                center.add(button);
            }
        }

        // initialize delay and add slider to control it at bottom
        JSlider slider = new JSlider(0, MAX_PAUSE - 20);
        setDelay(slider.getValue());
        slider.addChangeListener(this);
        JPanel south = new JPanel();
        south.add(new JLabel("slow"));
        south.add(slider);
        south.add(new JLabel("fast"));
        f.add(south, BorderLayout.SOUTH);

        // bring it on...
        f.setVisible(true);
        f.toFront();
    }

    public void place(int row, int col) {
        super.place(row, col);
        buttons[row - 1][col - 1].setText("Q");
        pause();
    }

    public boolean isSafe(int row, int col) {
        buttons[row - 1][col - 1].setText("?");
        pause();
        buttons[row - 1][col - 1].setText("");
        return super.isSafe(row, col);
    }

    public void remove(int row, int col) {
        super.remove(row, col);
        buttons[row - 1][col - 1].setText("X");
        pause();
        buttons[row - 1][col - 1].setText("");
    }

    // ChangeListener for slider
    public void stateChanged(ChangeEvent e) {
        setDelay(MAX_PAUSE - ((JSlider) e.getSource()).getValue());
    }
}