FileDriver.java

import javax.swing.*;
import javax.swing.filechooser.FileNameExtensionFilter;

import java.io.*;
import java.util.Scanner;

/**
 * This class is used to save and load games.
 * It is a subclass of the SudokuGUI class.
 * It inherits all the methods and variables of the SudokuGUI class.
 * 
 * JFILECHOOSER has been refernced from Oracle.com(2024).
 * Credited in the References in Report
 * 
 * @author Arun Kumar Sekar
 * @version January 2024
 * 
 */
public class FileDriver {

 /**
 * This method loads the previously saved game from the file (sudukoGUI.txt) in the same state it was saved in.
 * Constructor for objects of class FileDriver
 * Calls the constructor of the SudokuGUI class
 * Uses the file chooser from the swing package to enable the external file browser
 * Displays the file chooser to the user
 *
 * @throws FileNotFoundException if the file is not found
 */
 public static void saveGame(Sudoku theGame, int gridSize, JTextArea statusArea) {
 
 JFileChooser fileChooser = new JFileChooser();
 fileChooser.setFileFilter(new FileNameExtensionFilter("Sudoku Files", "txt"));
 int option = fileChooser.showSaveDialog(null); 

 if (option == JFileChooser.APPROVE_OPTION) {
 File saveFile = fileChooser.getSelectedFile();
 if (!saveFile.getName().endsWith(".txt")) {
 saveFile = new File(saveFile.getParentFile(), saveFile.getName() + ".txt");
 }

 try (PrintWriter writer = new PrintWriter(saveFile)) {
 writer.println(gridSize);

 for (int i = 0; i < gridSize; i++) {
 for (int j = 0; j < gridSize; j++) {
 String cellState = theGame.getIndividualMove(i, j);
 writer.println(i + " " + j + " " + cellState);
 }
 }
 statusArea.setText("Game saved to " + saveFile.getName());
 } catch (FileNotFoundException e) {
 statusArea.setText("Error saving game: " + e.getMessage());
 }
 }
 }

 /**
 * This method loads the previously saved game from the file (sudukoGUI.txt) in the same state it was saved in.
 * Constructor for objects of class FileDriver
 * Calls the constructor of the SudokuGUI class
 * Uses the file chooser from the swing package to enable the external file browser
 * Displays the file chooser to the user
 *
 * @throws FileNotFoundException if the file is not found
 */

 public static void loadGame(Sudoku theGame, int gridSize, JTextArea statusArea, SudokuGUI sudokuGUI) {
 JFileChooser fileChooser = new JFileChooser();
 fileChooser.setFileFilter(new FileNameExtensionFilter("Sudoku Files", "txt"));
 int option = fileChooser.showOpenDialog(null); // parent component to JFileChooser is null

 if (option == JFileChooser.APPROVE_OPTION) {
 File loadFile = fileChooser.getSelectedFile();

 try (Scanner scanner = new Scanner(loadFile)) {
 int savedGridSize = scanner.nextInt();
 if (savedGridSize != gridSize) {
 throw new IllegalStateException("Saved game size does not match current game size.");
 }

 while (scanner.hasNextInt()) {
 int row = scanner.nextInt();
 int col = scanner.nextInt();
 String value = scanner.next();
 theGame.makeMove(Integer.toString(row), Integer.toString(col), value);
 }
 sudokuGUI.displayGame();
 statusArea.setText("Game loaded from " + loadFile.getName());
 } catch (FileNotFoundException e) {
 statusArea.setText("Error loading game: " + e.getMessage());
 } catch (IllegalStateException e) {
 statusArea.setText(e.getMessage());
 }
 }
 }
}// End of FileDriver