SAE21_2023/SudokuButtonListener.java

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

public class SudokuButtonListener implements ActionListener {
    private int row;
    private int col;
    private Grid grid;
    private JButton[][] buttons;

    public SudokuButtonListener(int row, int col, Grid grid, JButton[][] buttons) {
        this.row = row;
        this.col = col;
        this.grid = grid;
        this.buttons = buttons;
    }

    @Override
    public void actionPerformed(ActionEvent e) {
        try {
            int num = Integer.parseInt(JOptionPane.showInputDialog("Enter a number:"));
            grid.getCell(row, col).setValue(num);
            if (num == 0) {
                buttons[row][col].setText(""); // Empty cell if the number is 0
            } else {
                buttons[row][col].setText(String.valueOf(num));
            }
            if (!isValidMove(num, row, col)) {
                buttons[row][col].setForeground(Color.RED); // Set text color to red for invalid move
            } else {
                buttons[row][col].setForeground(Color.BLACK); // Reset text color
            }
        } catch (NumberFormatException ex) {
            JOptionPane.showMessageDialog(null, "Please enter a valid number.");
        }
    }

    private boolean isValidMove(int num, int row, int col) {
        return isValidRow(num, row) && isValidCol(num, col) && isValidBox(num, row - row % 3, col - col % 3);
    }

    private boolean isValidRow(int num, int row) {
        for (int i = 0; i < 9; i++) {
            if (grid.getCell(row, i).getValue() == num && i != col) {
                return false;
            }
        }
        return true;
    }

    private boolean isValidCol(int num, int col) {
        for (int i = 0; i < 9; i++) {
            if (grid.getCell(i, col).getValue() == num && i != row) {
                return false;
            }
        }
        return true;
    }

    private boolean isValidBox(int num, int boxStartRow, int boxStartCol) {
        for (int i = 0; i < 3; i++) {
            for (int j = 0; j < 3; j++) {
                int row = i + boxStartRow;
                int col = j + boxStartCol;
                if (grid.getCell(row, col).getValue() == num && (row != this.row || col != this.col)) {
                    return false;
                }
            }
        }
        return true;
    }
}