Okay, this involves several steps: 1. **Database Schema Update:** Ensure the `quizzes` table has a `quiz_code` column (e.g., `VARCHAR(10) UNIQUE`). 2. **Quiz Code Generation:** Create a utility method to generate unique codes. 3. **DAO Layer (`QuizDao`):** Implement the logic to save the quiz and its questions within a transaction, including the generated code. 4. **Update `QuizCreatorFrame`:** Modify the `saveQuiz` method to generate the code, use the DAO, handle results with `SwingWorker`, and notify `HomeFrame`. 5. **Update `HomeFrame`:** Implement a mechanism (like a listener/callback) to refresh its quiz list when notified by `QuizCreatorFrame`. 6. **Participant Counts (Note):** Displaying live participant counts ("answered" / "taking now") is significantly more complex. It requires tracking active quiz sessions and completed attempts, usually involving additional tables and logic beyond the scope of just saving the quiz structure. We will focus on saving and displaying the created quiz first. Let's implement these steps. **Step 1 & 2: Update `DatabaseManager` and Add Code Generation Utility** * Ensure `quiz_code` is in your `users` table creation in `DatabaseManager.java`. * Add a utility class for code generation. java // src/com/quizsystem/dao/DatabaseManager.java - Ensure quiz_code is present // ... (inside initializeDatabase) String createQuizzesTable = "CREATE TABLE IF NOT EXISTS quizzes (" + "id INT AUTO_INCREMENT PRIMARY KEY, " + "title VARCHAR(255) NOT NULL, " + "description TEXT, " + "time_limit INT NOT NULL DEFAULT 60, " + "created_by VARCHAR(100), " + "quiz_code VARCHAR(10) UNIQUE NOT NULL" + // <<< ADDED UNIQUE NOT NULL ") ENGINE=InnoDB DEFAULT CHARSET=utf8mb4;"; stmt.execute(createQuizzesTable); // ... ```java // src/com/quizsystem/util/QuizCodeGenerator.java package com.quizsystem.util; import com.quizsystem.dao.QuizDao; // Assuming QuizDao exists import java.security.SecureRandom; import java.sql.SQLException; public class QuizCodeGenerator { private static final String ALPHANUMERIC = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; private static final int CODE_LENGTH = 6; // Adjust length as needed private static final SecureRandom random = new SecureRandom(); private static final int MAX_ATTEMPTS = 10; // Prevent infinite loops /** * Generates a unique alphanumeric quiz code. * Checks against the database using the provided DAO to ensure uniqueness. * * @param quizDao DAO to check for code existence. * @return A unique quiz code. * @throws SQLException if a database error occurs during checking. * @throws RuntimeException if a unique code cannot be generated after MAX_ATTEMPTS. */ public static String generateUniqueCode(QuizDao quizDao) throws SQLException { int attempts = 0; while (attempts < MAX_ATTEMPTS) { String code = generateRandomCode(CODE_LENGTH); if (!quizDao.quizCodeExists(code)) { return code; // Found unique code } attempts++; } // If we reach here, we failed to find a unique code after several tries throw new RuntimeException("Failed to generate a unique quiz code after " + MAX_ATTEMPTS + " attempts."); } private static String generateRandomCode(int length) { StringBuilder sb = new StringBuilder(length); for (int i = 0; i < length; i++) { sb.append(ALPHANUMERIC.charAt(random.nextInt(ALPHANUMERIC.length()))); } return sb.toString(); } } ``` **Step 3: Implement `QuizDao`** Create or update `QuizDao.java` to handle saving. package com.quizsystem.dao; import com.quizsystem.model.Question; import com.quizsystem.model.Quiz; import java.sql.*; import java.util.List; import java.util.Optional; // If needed for find methods public class QuizDao { /** * Saves a Quiz and its associated Questions to the database within a transaction. * Assumes the Quiz object already has its quiz_code set. * * @param quiz The Quiz object to save (must have quiz_code). * @param questions The List of Question objects associated with the quiz. * @return The generated ID of the saved quiz. * @throws SQLException if a database error occurs or the transaction fails. */ public int saveQuizWithQuestions(Quiz quiz, List questions) throws SQLException { Connection conn = null; PreparedStatement pstmtQuiz = null; PreparedStatement pstmtQuestion = null; ResultSet generatedKeys = null; int quizId = -1; // Default to -1 to indicate failure String sqlQuiz = "INSERT INTO quizzes (title, description, time_limit, created_by, quiz_code) VALUES (?, ?, ?, ?, ?)"; String sqlQuestion = "INSERT INTO questions (quiz_id, question_text, type, option_a, option_b, option_c, option_d, correct_option, points) VALUES (?, ?, ?, ?, ?, ?, ?, ?, ?)"; try { conn = DatabaseManager.getConnection(); conn.setAutoCommit(false); // Start transaction // --- Insert Quiz --- pstmtQuiz = conn.prepareStatement(sqlQuiz, Statement.RETURN_GENERATED_KEYS); pstmtQuiz.setString(1, quiz.getTitle()); pstmtQuiz.setString(2, quiz.getDescription()); pstmtQuiz.setInt(3, quiz.getTimeLimit()); pstmtQuiz.setString(4, quiz.getCreatedBy()); pstmtQuiz.setString(5, quiz.getQuizCode()); // Save the generated code int affectedRows = pstmtQuiz.executeUpdate(); if (affectedRows == 0) { throw new SQLException("Creating quiz failed, no rows affected."); } // --- Get Generated Quiz ID --- generatedKeys = pstmtQuiz.getGeneratedKeys(); if (generatedKeys.next()) { quizId = generatedKeys.getInt(1); quiz.setId(quizId); // Update the quiz object with its ID } else { throw new SQLException("Creating quiz failed, no ID obtained."); } generatedKeys.close(); // Close keys ResultSet pstmtQuiz.close(); // Close quiz statement // --- Insert Questions (Batch Recommended for Performance) --- pstmtQuestion = conn.prepareStatement(sqlQuestion); for (Question question : questions) { question.setQuizId(quizId); // Set the foreign key pstmtQuestion.setInt(1, question.getQuizId()); pstmtQuestion.setString(2, question.getQuestionText()); pstmtQuestion.setString(3, question.getType()); pstmtQuestion.setString(4, question.getOptionA()); pstmtQuestion.setString(5, question.getOptionB()); pstmtQuestion.setString(6, question.getOptionC()); pstmtQuestion.setString(7, question.getOptionD()); pstmtQuestion.setString(8, question.getCorrectOption()); pstmtQuestion.setInt(9, question.getPoints()); pstmtQuestion.addBatch(); // Add statement to batch } int[] batchResults = pstmtQuestion.executeBatch(); // Execute all batched inserts // Optional: Check batchResults for errors if needed for (int result : batchResults) { if (result == Statement.EXECUTE_FAILED) { throw new SQLException("Executing batch failed for one or more questions."); } } conn.commit(); // Commit transaction if all successful System.out.println("Quiz and questions saved successfully. Quiz ID: " + quizId); } catch (SQLException e) { System.err.println("Transaction failed! Rolling back. Error: " + e.getMessage()); if (conn != null) { try { conn.rollback(); // Rollback on error } catch (SQLException ex) { System.err.println("Error during rollback: " + ex.getMessage()); } } throw e; // Re-throw the exception after attempting rollback } finally { // Close resources in finally block if (generatedKeys != null) try { generatedKeys.close(); } catch (SQLException e) { /* ignored */ } if (pstmtQuiz != null) try { pstmtQuiz.close(); } catch (SQLException e) { /* ignored */ } if (pstmtQuestion != null) try { pstmtQuestion.close(); } catch (SQLException e) { /* ignored */ } if (conn != null) { try { conn.setAutoCommit(true); // Restore default commit behavior conn.close(); // Close connection } catch (SQLException e) { System.err.println("Error closing connection: " + e.getMessage()); } } } return quizId; // Return the generated quiz ID } /** * Checks if a given quiz code already exists in the database. * * @param code The quiz code to check. * @return true if the code exists, false otherwise. * @throws SQLException if a database error occurs. */ public boolean quizCodeExists(String code) throws SQLException { String sql = "SELECT 1 FROM quizzes WHERE quiz_code = ? LIMIT 1"; try (Connection conn = DatabaseManager.getConnection(); PreparedStatement pstmt = conn.prepareStatement(sql)) { pstmt.setString(1, code); try (ResultSet rs = pstmt.executeQuery()) { return rs.next(); // True if a row is found } } } // --- Add other necessary DAO methods --- // E.g., findQuizById, findAllQuizzes, findQuizByCode, deleteQuiz, updateQuiz etc. /** * Fetches all available quizzes from the database. * (Example - adjust columns as needed, especially add quiz_code) * * @return A List of Quiz objects. * @throws SQLException if a database error occurs. */ public List findAllQuizzes() throws SQLException { List quizzes = new ArrayList<>(); // Include quiz_code in the SELECT statement String sql = "SELECT id, title, description, time_limit, created_by, quiz_code FROM quizzes ORDER BY title"; try (Connection conn = DatabaseManager.getConnection(); Statement stmt = conn.createStatement(); ResultSet rs = stmt.executeQuery(sql)) { while (rs.next()) { Quiz quiz = new Quiz(); quiz.setId(rs.getInt("id")); quiz.setTitle(rs.getString("title")); quiz.setDescription(rs.getString("description")); quiz.setTimeLimit(rs.getInt("time_limit")); quiz.setCreatedBy(rs.getString("created_by")); quiz.setQuizCode(rs.getString("quiz_code")); // Fetch the code quizzes.add(quiz); } } return quizzes; } } **Step 4 & 5: Update `QuizCreatorFrame` and `HomeFrame` for Communication** * Define a listener interface. * Modify `HomeFrame` to implement it. * Modify `QuizCreatorFrame` to accept and notify the listener. ```java // src/com/quizsystem/ui/listeners/QuizCreationListener.java package com.quizsystem.ui.listeners; // Simple listener interface public interface QuizCreationListener { void quizCreated(); // Method called when a quiz is successfully created } ``` package com.quizsystem.ui; import com.quizsystem.dao.DatabaseManager; import com.quizsystem.dao.QuizDao; import com.quizsystem.model.Question; import com.quizsystem.model.Quiz; import com.quizsystem.ui.listeners.QuizCreationListener; // Import listener import com.quizsystem.util.QuizCodeGenerator; // Import generator import javax.swing.*; import javax.swing.border.Border; import javax.swing.border.EmptyBorder; import javax.swing.border.TitledBorder; import java.awt.*; import java.sql.Connection; import java.sql.SQLException; import java.util.ArrayList; import java.util.List; public class QuizCreatorFrame extends JFrame { private final String currentUser; private JTextField quizTitleField; private JTextArea quizDescriptionArea; private JSpinner timeLimitSpinner; private JComboBox quizModeComboBox; private JButton addQuestionButton, saveQuizButton; private JPanel questionsContainerPanel; private JScrollPane questionsScrollPane; private final List questionPanels = new ArrayList<>(); private final QuizCreationListener creationListener; // Listener reference // Constants for quiz modes private static final String MULTIPLE_CHOICE = "Multiple Choice"; private static final String IDENTIFICATION = "Identification"; private static final String TRUE_FALSE = "True or False"; // Constructor now accepts the listener public QuizCreatorFrame(String username, QuizCreationListener listener) { this.currentUser = username; this.creationListener = listener; // Store the listener setTitle("Create a New Quiz - Logged in as: " + currentUser); setSize(750, 600); setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE); setLocationRelativeTo(null); initComponents(); layoutComponents(); attachListeners(); } // --- initComponents, layoutComponents, attachListeners, add/remove/renumber QuestionPanel methods remain the same --- // (Copy from previous good version) private void initComponents() { quizTitleField = new JTextField(30); quizDescriptionArea = new JTextArea(3, 30); quizDescriptionArea.setLineWrap(true); quizDescriptionArea.setWrapStyleWord(true); timeLimitSpinner = new JSpinner(new SpinnerNumberModel(60, 1, 3600, 10)); String[] quizModes = {MULTIPLE_CHOICE, IDENTIFICATION, TRUE_FALSE}; quizModeComboBox = new JComboBox<>(quizModes); addQuestionButton = new JButton("Add Question"); saveQuizButton = new JButton("Save Quiz"); questionsContainerPanel = new JPanel(); questionsContainerPanel.setLayout(new BoxLayout(questionsContainerPanel, BoxLayout.Y_AXIS)); questionsScrollPane = new JScrollPane(questionsContainerPanel); questionsScrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED); questionsScrollPane.setHorizontalScrollBarPolicy(JScrollPane.HORIZONTAL_SCROLLBAR_NEVER); questionsScrollPane.setBorder(new TitledBorder("Questions")); questionsScrollPane.getVerticalScrollBar().setUnitIncrement(16); } private void layoutComponents() { JPanel mainPanel = new JPanel(new BorderLayout(10, 10)); mainPanel.setBorder(new EmptyBorder(10, 10, 10, 10)); JPanel detailsPanel = new JPanel(new GridBagLayout()); detailsPanel.setBorder(new TitledBorder("Quiz Details")); GridBagConstraints gbc = new GridBagConstraints(); gbc.gridx = 0; gbc.gridy = 0; gbc.anchor = GridBagConstraints.WEST; gbc.insets = new Insets(5, 5, 5, 5); detailsPanel.add(new JLabel("Title:"), gbc); gbc.gridx++; gbc.fill = GridBagConstraints.HORIZONTAL; gbc.weightx = 1.0; detailsPanel.add(quizTitleField, gbc); gbc.gridx = 0; gbc.gridy++; gbc.fill = GridBagConstraints.NONE; gbc.weightx = 0; detailsPanel.add(new JLabel("Description:"), gbc); gbc.gridx++; gbc.fill = GridBagConstraints.HORIZONTAL; gbc.weightx = 1.0; JScrollPane descScrollPane = new JScrollPane(quizDescriptionArea); descScrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED); detailsPanel.add(descScrollPane, gbc); gbc.gridx = 0; gbc.gridy++; gbc.fill = GridBagConstraints.NONE; gbc.weightx = 0; detailsPanel.add(new JLabel("Time Limit (seconds):"), gbc); gbc.gridx++; gbc.fill = GridBagConstraints.HORIZONTAL; gbc.weightx = 1.0; detailsPanel.add(timeLimitSpinner, gbc); gbc.gridx = 0; gbc.gridy++; gbc.fill = GridBagConstraints.NONE; gbc.weightx = 0; detailsPanel.add(new JLabel("Default Question Type:"), gbc); gbc.gridx++; gbc.fill = GridBagConstraints.HORIZONTAL; gbc.weightx = 1.0; detailsPanel.add(quizModeComboBox, gbc); mainPanel.add(detailsPanel, BorderLayout.NORTH); mainPanel.add(questionsScrollPane, BorderLayout.CENTER); JPanel buttonPanel = new JPanel(new FlowLayout(FlowLayout.RIGHT)); buttonPanel.add(addQuestionButton); buttonPanel.add(saveQuizButton); mainPanel.add(buttonPanel, BorderLayout.SOUTH); add(mainPanel); } private void attachListeners() { addQuestionButton.addActionListener(e -> addQuestionPanel()); saveQuizButton.addActionListener(e -> saveQuiz()); } private void addQuestionPanel() { String selectedMode = (String) quizModeComboBox.getSelectedItem(); if (selectedMode == null) { JOptionPane.showMessageDialog(this, "Please select a default question type first.", "Warning", JOptionPane.WARNING_MESSAGE); return; } int questionNumber = questionPanels.size() + 1; QuestionInputPanel newQuestionPanel = new QuestionInputPanel(selectedMode, questionNumber); newQuestionPanel.getRemoveButton().addActionListener(e -> removeQuestionPanel(newQuestionPanel)); questionPanels.add(newQuestionPanel); questionsContainerPanel.add(newQuestionPanel); questionsContainerPanel.add(Box.createRigidArea(new Dimension(0, 5))); questionsContainerPanel.revalidate(); questionsContainerPanel.repaint(); SwingUtilities.invokeLater(() -> { JScrollBar sb = questionsScrollPane.getVerticalScrollBar(); sb.setValue(sb.getMaximum()); }); } private void removeQuestionPanel(QuestionInputPanel panelToRemove) { questionPanels.remove(panelToRemove); questionsContainerPanel.remove(panelToRemove); Component[] components = questionsContainerPanel.getComponents(); if (components.length > 0 && components[components.length - 1] instanceof Box.Filler) { questionsContainerPanel.remove(components.length - 1); } renumberQuestionPanels(); questionsContainerPanel.revalidate(); questionsContainerPanel.repaint(); } private void renumberQuestionPanels() { for (int i = 0; i < questionPanels.size(); i++) { questionPanels.get(i).setQuestionNumber(i + 1); } } // --- End of unchanged methods --- private void saveQuiz() { // 1. Validate Quiz Details (as before) String quizTitle = quizTitleField.getText().trim(); String quizDescription = quizDescriptionArea.getText().trim(); int timeLimit = (Integer) timeLimitSpinner.getValue(); if (quizTitle.isEmpty()) { showError("Quiz title cannot be empty.", quizTitleField); return; } if (questionPanels.isEmpty()) { showError("Please add at least one question to the quiz.", addQuestionButton); return; } // 2. Collect Question Data and Validate (as before) List questions = new ArrayList<>(); for (int i = 0; i < questionPanels.size(); i++) { QuestionInputPanel qip = questionPanels.get(i); try { Question question = qip.getQuestionData(); questions.add(question); qip.resetBorder(); // Reset border on successful validation } catch (IllegalArgumentException ex) { showError("Error in Question #" + (i + 1) + ": " + ex.getMessage(), qip); qip.highlightError(); // Highlight the problematic panel return; // Stop saving process } } // Disable button while saving saveQuizButton.setEnabled(false); addQuestionButton.setEnabled(false); // Also disable adding questions // Use SwingWorker for DB operations (code generation + saving) SwingWorker worker = new SwingWorker() { private String generatedCode = null; private String failureReason = null; @Override protected Boolean doInBackground() throws Exception { QuizDao quizDao = new QuizDao(); try { // 3. Generate Unique Quiz Code generatedCode = QuizCodeGenerator.generateUniqueCode(quizDao); // 4. Create Quiz Object Quiz newQuiz = new Quiz(); newQuiz.setTitle(quizTitle); newQuiz.setDescription(quizDescription); newQuiz.setTimeLimit(timeLimit); newQuiz.setCreatedBy(currentUser); newQuiz.setQuizCode(generatedCode); // Set the generated code // 5. Save to Database quizDao.saveQuizWithQuestions(newQuiz, questions); return true; // Indicate success } catch (SQLException e) { failureReason = "Database error: " + e.getMessage(); System.err.println("DB Error saving quiz: " + e.getMessage()); e.printStackTrace(); return false; } catch (RuntimeException e) { // Catch code generation failure failureReason = "Code generation error: " + e.getMessage(); System.err.println("Code Gen Error saving quiz: " + e.getMessage()); e.printStackTrace(); return false; } catch (Exception e) { failureReason = "An unexpected error occurred: " + e.getMessage(); System.err.println("Unexpected Error saving quiz: " + e.getMessage()); e.printStackTrace(); return false; } } @Override protected void done() { try { boolean success = get(); // Get result from doInBackground if (success) { JOptionPane.showMessageDialog(QuizCreatorFrame.this, "Quiz '" + quizTitle + "' saved successfully!\nJoin Code: " + generatedCode, "Success", JOptionPane.INFORMATION_MESSAGE); // Notify the listener (HomeFrame) to refresh if (creationListener != null) { creationListener.quizCreated(); } dispose(); // Close the creator frame } else { showError(failureReason != null ? failureReason : "Failed to save quiz.", saveQuizButton); } } catch (Exception e) { // Handle exceptions from get() or during done() showError("An error occurred while finalizing the save operation.", saveQuizButton); System.err.println("Error in SwingWorker done(): " + e.getMessage()); e.printStackTrace(); } finally { // Re-enable buttons saveQuizButton.setEnabled(true); addQuestionButton.setEnabled(true); } } }; worker.execute(); // Start the background task } // showError helper method (as before) private void showError(String message, Component componentToFocus) { JOptionPane.showMessageDialog(this, message, "Error", JOptionPane.ERROR_MESSAGE); if (componentToFocus != null) { SwingUtilities.invokeLater(componentToFocus::requestFocusInWindow); } } // --- QuestionInputPanel Inner Class (MUST BE INCLUDED HERE) --- // (Copy the full QuestionInputPanel class from the previous response here) private static class QuestionInputPanel extends JPanel { private final String questionType; private int questionNumber; private JLabel questionNumberLabel; // Can be removed if border title is enough private JTextArea questionTextArea; private JTextField optionAField, optionBField, optionCField, optionDField; private JTextField identificationAnswerField; private JRadioButton trueRadioButton, falseRadioButton; private ButtonGroup trueFalseGroup; private JComboBox correctAnswerComboBox; // For MC private JButton removeButton; private Border defaultBorder; // Store default border public QuestionInputPanel(String questionType, int questionNumber) { this.questionType = questionType; this.questionNumber = questionNumber; setLayout(new GridBagLayout()); this.defaultBorder = BorderFactory.createCompoundBorder( BorderFactory.createTitledBorder("Question #" + questionNumber + " (" + questionType + ")"), BorderFactory.createEmptyBorder(5, 5, 5, 5) ); setBorder(this.defaultBorder); initComponents(); layoutComponents(); } public void setQuestionNumber(int number) { this.questionNumber = number; Border currentBorder = getBorder(); if (currentBorder instanceof CompoundBorder compoundBorder) { Border outerBorder = compoundBorder.getOutsideBorder(); if (outerBorder instanceof TitledBorder titledBorder) { titledBorder.setTitle("Question #" + number + " (" + questionType + ")"); repaint(); } } } public JButton getRemoveButton() { return removeButton; } public void highlightError() { setBorder(BorderFactory.createCompoundBorder( BorderFactory.createTitledBorder(BorderFactory.createLineBorder(Color.RED, 2), ((TitledBorder) defaultBorder.getBorder(0)).getTitle()), BorderFactory.createEmptyBorder(5, 5, 5, 5) )); } public void resetBorder() { setBorder(defaultBorder); } private void initComponents() { questionTextArea = new JTextArea(3, 40); questionTextArea.setLineWrap(true); questionTextArea.setWrapStyleWord(true); questionTextArea.setBorder(BorderFactory.createLineBorder(Color.LIGHT_GRAY)); removeButton = new JButton("Remove"); removeButton.setToolTipText("Remove this question"); removeButton.setForeground(Color.RED.darker()); removeButton.setMargin(new Insets(2, 5, 2, 5)); switch (questionType) { case MULTIPLE_CHOICE: optionAField = new JTextField(15); optionBField = new JTextField(15); optionCField = new JTextField(15); optionDField = new JTextField(15); correctAnswerComboBox = new JComboBox<>(new String[]{"A", "B", "C", "D"}); break; case IDENTIFICATION: identificationAnswerField = new JTextField(20); break; case TRUE_FALSE: trueRadioButton = new JRadioButton("True"); falseRadioButton = new JRadioButton("False"); trueFalseGroup = new ButtonGroup(); trueFalseGroup.add(trueRadioButton); trueFalseGroup.add(falseRadioButton); trueRadioButton.setSelected(true); break; } } private void layoutComponents() { GridBagConstraints gbc = new GridBagConstraints(); gbc.gridx = 0; gbc.gridy = 0; gbc.anchor = GridBagConstraints.WEST; gbc.insets = new Insets(2, 5, 2, 5); gbc.gridwidth = 3; gbc.weightx = 1.0; gbc.fill = GridBagConstraints.HORIZONTAL; add(new JLabel("Question Text:"), gbc); gbc.gridx = 3; gbc.gridwidth = 1; gbc.weightx = 0; gbc.fill = GridBagConstraints.NONE; gbc.anchor = GridBagConstraints.NORTHEAST; add(removeButton, gbc); gbc.anchor = GridBagConstraints.WEST; gbc.gridx = 0; gbc.gridy++; gbc.gridwidth = 4; gbc.fill = GridBagConstraints.BOTH; gbc.weightx = 1.0; gbc.weighty = 1.0; JScrollPane textScrollPane = new JScrollPane(questionTextArea); textScrollPane.setVerticalScrollBarPolicy(JScrollPane.VERTICAL_SCROLLBAR_AS_NEEDED); add(textScrollPane, gbc); gbc.weighty = 0; gbc.fill = GridBagConstraints.HORIZONTAL; gbc.gridy++; gbc.gridwidth = 1; switch (questionType) { case MULTIPLE_CHOICE: layoutMultipleChoice(gbc); break; case IDENTIFICATION: layoutIdentification(gbc); break; case TRUE_FALSE: layoutTrueFalse(gbc); break; } } private void layoutMultipleChoice(GridBagConstraints gbc) { gbc.gridx = 0; add(new JLabel("A:"), gbc); gbc.gridx = 1; add(optionAField, gbc); gbc.gridx = 2; add(new JLabel("B:"), gbc); gbc.gridx = 3; add(optionBField, gbc); gbc.gridy++; gbc.gridx = 0; add(new JLabel("C:"), gbc); gbc.gridx = 1; add(optionCField, gbc); gbc.gridx = 2; add(new JLabel("D:"), gbc); gbc.gridx = 3; add(optionDField, gbc); gbc.gridy++; gbc.gridx = 0; add(new JLabel("Correct:"), gbc); gbc.gridx = 1; gbc.gridwidth = 3; add(correctAnswerComboBox, gbc); } private void layoutIdentification(GridBagConstraints gbc) { gbc.gridx = 0; add(new JLabel("Answer:"), gbc); gbc.gridx = 1; gbc.gridwidth = 3; add(identificationAnswerField, gbc); } private void layoutTrueFalse(GridBagConstraints gbc) { gbc.gridx = 0; add(new JLabel("Correct:"), gbc); JPanel radioPanel = new JPanel(new FlowLayout(FlowLayout.LEFT, 0, 0)); radioPanel.add(trueRadioButton); radioPanel.add(falseRadioButton); gbc.gridx = 1; gbc.gridwidth = 3; add(radioPanel, gbc); } public Question getQuestionData() throws IllegalArgumentException { String questionText = questionTextArea.getText().trim(); if (questionText.isEmpty()) { throw new IllegalArgumentException("Question text cannot be empty."); } Question question = new Question(); question.setQuestionText(questionText); question.setType(questionType); question.setPoints(1); switch (questionType) { case MULTIPLE_CHOICE: String optA = optionAField.getText().trim(); String optB = optionBField.getText().trim(); String optC = optionCField.getText().trim(); String optD = optionDField.getText().trim(); if (optA.isEmpty() || optB.isEmpty() || optC.isEmpty() || optD.isEmpty()) { throw new IllegalArgumentException("All four options (A, B, C, D) must be provided for Multiple Choice."); } question.setOptionA(optA); question.setOptionB(optB); question.setOptionC(optC); question.setOptionD(optD); question.setCorrectOption((String) correctAnswerComboBox.getSelectedItem()); break; case IDENTIFICATION: String answer = identificationAnswerField.getText().trim(); if (answer.isEmpty()) { throw new IllegalArgumentException("Answer cannot be empty for Identification."); } question.setCorrectOption(answer); break; case TRUE_FALSE: if (!trueRadioButton.isSelected() && !falseRadioButton.isSelected()) { throw new IllegalArgumentException("Please select True or False as the correct answer."); } question.setCorrectOption(trueRadioButton.isSelected() ? "True" : "False"); break; } return question; } } // --- End of QuestionInputPanel Inner Class --- // --- Dummy classes (REMOVE IF ACTUAL IMPLEMENTATIONS EXIST) --- static class DatabaseManager { public static Connection getConnection() throws SQLException { System.err.println("Warning: Using dummy DatabaseManager"); throw new SQLException("Dummy DB connection"); } } // static class QuizDao { public boolean saveQuizWithQuestions(Quiz quiz, List questions) throws SQLException { System.out.println("Simulating save quiz: " + quiz.getTitle()); return true; } public boolean quizCodeExists(String code) throws SQLException { return false; } } // static class Quiz { private int id; private String title; private String description; private int timeLimit; private String createdBy; private String quizCode; public int getId() { return id; } public void setId(int id) { this.id = id; } public String getTitle() { return title; } public void setTitle(String title) { this.title = title; } public String getDescription() { return description; } public void setDescription(String description) { this.description = description; } public int getTimeLimit() { return timeLimit; } public void setTimeLimit(int timeLimit) { this.timeLimit = timeLimit; } public String getCreatedBy() { return createdBy; } public void setCreatedBy(String createdBy) { this.createdBy = createdBy; } public String getQuizCode() { return quizCode; } public void setQuizCode(String quizCode) { this.quizCode = quizCode; } } // static class Question { private int id; private int quizId; private String questionText; private String type; private String optionA, optionB, optionC, optionD; private String correctOption; private int points; public int getId() { return id; } public void setId(int id) { this.id = id; } public int getQuizId() { return quizId; } public void setQuizId(int quizId) { this.quizId = quizId; } public String getQuestionText() { return questionText; } public void setQuestionText(String questionText) { this.questionText = questionText; } public String getType() { return type; } public void setType(String type) { this.type = type; } public String getOptionA() { return optionA; } public void setOptionA(String optionA) { this.optionA = optionA; } public String getOptionB() { return optionB; } public void setOptionB(String optionB) { this.optionB = optionB; } public String getOptionC() { return optionC; } public void setOptionC(String optionC) { this.optionC = optionC; } public String getOptionD() { return optionD; } public void setOptionD(String optionD) { this.optionD = optionD; } public String getCorrectOption() { return correctOption; } public void setCorrectOption(String correctOption) { this.correctOption = correctOption; } public int getPoints() { return points; } public void setPoints(int points) { this.points = points; } } // Main method for testing public static void main(String[] args) { com.quizsystem.util.PreferencesManager.applySavedLookAndFeel(); SwingUtilities.invokeLater(() -> { // Example of creating with a dummy listener for testing QuizCreationListener dummyListener = () -> System.out.println("QuizCreated notification received by dummy listener."); QuizCreatorFrame creatorFrame = new QuizCreatorFrame("TestUser", dummyListener); creatorFrame.setVisible(true); }); } } package com.quizsystem.ui; import com.quizsystem.dao.DatabaseManager; import com.quizsystem.dao.QuizDao; // Import QuizDao import com.quizsystem.model.Quiz; import com.quizsystem.ui.listeners.QuizCreationListener; // Import listener import javax.swing.*; import java.awt.*; import java.awt.event.ActionEvent; import java.sql.Connection; // Keep for dummy DB Manager import java.sql.ResultSet; // Keep for dummy DB Manager import java.sql.SQLException; import java.sql.Statement; // Keep for dummy DB Manager import java.util.ArrayList; import java.util.List; // Implement the listener interface public class HomeFrame extends JFrame implements QuizCreationListener { private final String currentUser; private JList quizList; private DefaultListModel listModel; private JButton addQuizButton; private QuizDao quizDao; // Add DAO instance public HomeFrame(String username) { this.currentUser = username; this.quizDao = new QuizDao(); // Instantiate DAO setTitle("Online Quiz System - Welcome, " + username); setSize(800, 600); setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE); setLocationRelativeTo(null); JPanel mainPanel = new JPanel(new BorderLayout(10, 10)); mainPanel.setBorder(BorderFactory.createEmptyBorder(10, 10, 10, 10)); mainPanel.add(createHeaderPanel(), BorderLayout.NORTH); mainPanel.add(createNavigationPanel(), BorderLayout.WEST); mainPanel.add(createContentPanel(), BorderLayout.CENTER); add(mainPanel); loadQuizzes(); // Load quizzes initially } // --- createHeaderPanel, createNavButton, createContentPanel methods remain the same --- private JPanel createHeaderPanel() { JPanel headerPanel = new JPanel(new FlowLayout(FlowLayout.LEFT)); headerPanel.add(new JLabel("Welcome, " + currentUser)); addQuizButton = new JButton("+"); addQuizButton.setToolTipText("Add or Join Quiz"); addQuizButton.addActionListener(this::showQuizMenu); headerPanel.add(addQuizButton); return headerPanel; } private JPanel createNavigationPanel() { JPanel navPanel = new JPanel(); navPanel.setLayout(new BoxLayout(navPanel, BoxLayout.Y_AXIS)); navPanel.setBorder(BorderFactory.createEmptyBorder(0, 0, 0, 10)); JButton homeButton = createNavButton("Quizzes"); JButton profileButton = createNavButton("Profile"); JButton scoresButton = createNavButton("Scores"); JButton settingsButton = createNavButton("Settings"); JButton logoutButton = createNavButton("Logout"); navPanel.add(homeButton); navPanel.add(Box.createRigidArea(new Dimension(0, 10))); navPanel.add(profileButton); navPanel.add(Box.createRigidArea(new Dimension(0, 10))); navPanel.add(scoresButton); navPanel.add(Box.createRigidArea(new Dimension(0, 10))); navPanel.add(settingsButton); navPanel.add(Box.createVerticalGlue()); navPanel.add(logoutButton); homeButton.addActionListener(e -> loadQuizzes()); profileButton.addActionListener(e -> openProfileFrame()); scoresButton.addActionListener(e -> openScoresFrame()); settingsButton.addActionListener(e -> openSettingsFrame()); logoutButton.addActionListener(e -> logout()); return navPanel; } private JButton createNavButton(String text) { JButton button = new JButton(text); button.setAlignmentX(Component.LEFT_ALIGNMENT); button.setMaximumSize(new Dimension(Integer.MAX_VALUE, button.getPreferredSize().height)); return button; } private JPanel createContentPanel() { JPanel contentPanel = new JPanel(new BorderLayout(0, 10)); listModel = new DefaultListModel<>(); quizList = new JList<>(listModel); quizList.setCellRenderer(new QuizListRenderer()); quizList.setSelectionMode(ListSelectionModel.SINGLE_SELECTION); JScrollPane scrollPane = new JScrollPane(quizList); contentPanel.add(scrollPane, BorderLayout.CENTER); JButton startQuizButton = new JButton("Start Selected Quiz"); startQuizButton.addActionListener(e -> startSelectedQuiz()); contentPanel.add(startQuizButton, BorderLayout.SOUTH); return contentPanel; } // --- End of unchanged methods --- // --- Action Methods --- private void showQuizMenu(ActionEvent event) { JPopupMenu quizMenu = new JPopupMenu(); JMenuItem joinQuizItem = new JMenuItem("Join a Quiz"); joinQuizItem.addActionListener(this::joinQuizAction); JMenuItem createQuizItem = new JMenuItem("Create a Quiz"); // Pass 'this' as the listener when creating the frame createQuizItem.addActionListener(e -> new QuizCreatorFrame(currentUser, this).setVisible(true)); quizMenu.add(joinQuizItem); quizMenu.add(createQuizItem); Component source = (Component) event.getSource(); quizMenu.show(source, 0, source.getHeight()); } private void joinQuizAction(ActionEvent e) { String code = JOptionPane.showInputDialog(this, "Enter the quiz code:", "Join Quiz", JOptionPane.PLAIN_MESSAGE); if (code != null && !code.trim().isEmpty()) { String trimmedCode = code.trim().toUpperCase(); // Standardize code format // TODO: Implement findQuizByCode in QuizDao // try { // Optional quizOpt = quizDao.findQuizByCode(trimmedCode); // if (quizOpt.isPresent()) { // new QuizFrame(currentUser, quizOpt.get()).setVisible(true); // } else { // JOptionPane.showMessageDialog(this, "Quiz code '" + trimmedCode + "' not found.", "Not Found", JOptionPane.WARNING_MESSAGE); // } // } catch (SQLException ex) { // JOptionPane.showMessageDialog(this, "Database error checking quiz code.", "Error", JOptionPane.ERROR_MESSAGE); // System.err.println("DB Error finding quiz by code: " + ex.getMessage()); // } JOptionPane.showMessageDialog(this, "Joining quiz by code not fully implemented yet.", "Info", JOptionPane.INFORMATION_MESSAGE); } else if (code != null) { JOptionPane.showMessageDialog(this, "Quiz code cannot be empty.", "Invalid Input", JOptionPane.WARNING_MESSAGE); } } // Public method to refresh the list (can be called by listener) public void loadQuizzes() { System.out.println("HomeFrame: Refreshing quiz list..."); // Debug message listModel.clear(); try { List quizzes = quizDao.findAllQuizzes(); // Use DAO method if (quizzes.isEmpty()) { // Optionally display a message in the list area listModel.addElement(new Quiz(){ // Add a dummy item to show message @Override public String toString() { return "No quizzes available."; } }); quizList.setEnabled(false); // Disable selection } else { quizList.setEnabled(true); for (Quiz quiz : quizzes) { listModel.addElement(quiz); } } } catch (SQLException e) { JOptionPane.showMessageDialog(this, "Error loading quizzes from the database: " + e.getMessage(), "Database Error", JOptionPane.ERROR_MESSAGE); System.err.println("SQL Error loading quizzes: " + e.getMessage()); } catch (Exception e) { JOptionPane.showMessageDialog(this, "An unexpected error occurred while loading quizzes.", "Error", JOptionPane.ERROR_MESSAGE); System.err.println("Error loading quizzes: " + e.getMessage()); e.printStackTrace(); } } // fetchAvailableQuizzes is replaced by loadQuizzes using DAO private void startSelectedQuiz() { Quiz selectedQuiz = quizList.getSelectedValue(); // Prevent starting the dummy "No quizzes" item if (selectedQuiz != null && selectedQuiz.getId() > 0) { // Ensure QuizFrame exists and is correctly imported/packaged new QuizFrame(currentUser, selectedQuiz).setVisible(true); } else if (selectedQuiz == null) { JOptionPane.showMessageDialog(this, "Please select a quiz from the list first.", "No Quiz Selected", JOptionPane.WARNING_MESSAGE); } } // --- Navigation Methods (openProfileFrame, openScoresFrame, openSettingsFrame, logout) remain the same --- private void openProfileFrame() { new ProfileFrame(currentUser).setVisible(true); } private void openScoresFrame() { new ScoresFrame(currentUser).setVisible(true); } private void openSettingsFrame() { new SettingsFrame(currentUser).setVisible(true); } private void logout() { int response = JOptionPane.showConfirmDialog(this, "Are you sure you want to logout?", "Confirm Logout", JOptionPane.YES_NO_OPTION, JOptionPane.QUESTION_MESSAGE); if (response == JOptionPane.YES_OPTION) { dispose(); new LoginFrame().setVisible(true); } } // --- End of unchanged navigation methods --- // --- QuizCreationListener Implementation --- @Override public void quizCreated() { // This method is called by QuizCreatorFrame upon successful save System.out.println("HomeFrame: Received quizCreated notification."); // Debug message // Refresh the quiz list on the Event Dispatch Thread SwingUtilities.invokeLater(this::loadQuizzes); } // --- QuizListRenderer Inner Class (Now uses Quiz model properly) --- private static class QuizListRenderer extends DefaultListCellRenderer { @Override public Component getListCellRendererComponent(JList list, Object value, int index, boolean isSelected, boolean cellHasFocus) { // Call super for default styling Component renderer = super.getListCellRendererComponent(list, value, index, isSelected, cellHasFocus); if (value instanceof Quiz quiz) { // Check if it's a real quiz or the placeholder message if (quiz.getId() > 0) { // Format real quiz entries String title = escapeHtml(quiz.getTitle()); String desc = escapeHtml(quiz.getDescription()); String code = escapeHtml(quiz.getQuizCode()); // Display the code int time = quiz.getTimeLimit(); setText("

" + "" + title + " (Code: " + code + ")
" + (desc != null && !desc.isEmpty() ? desc + "
" : "") + "Time: " + time + "s | By: " + escapeHtml(quiz.getCreatedBy()) + "" + // Placeholder for participant counts - requires more data // "
Taking: ? | Answered: ?" + "

"); setToolTipText("Code: " + code + " | " + (desc != null ? desc : "No description")); renderer.setEnabled(list.isEnabled()); // Ensure item is enabled/disabled with list } else { // Format the placeholder message ("No quizzes available.") setText("

" + quiz.toString() + "

"); renderer.setEnabled(false); // Disable selection of placeholder } } else { // Handle unexpected types or null setText(value == null ? "" : value.toString()); renderer.setEnabled(list.isEnabled()); } return renderer; } private String escapeHtml(String text) { if (text == null) return ""; return text.replace("&", "&") .replace("<", "<") .replace(">", ">") .replace("\"", """) .replace("'", "'"); } } // --- Dummy classes REMOVED (Assuming actual implementations exist) --- // static class DatabaseManager { ... } // static class Quiz { ... } // --- Main method for testing --- public static void main(String[] args) { com.quizsystem.util.PreferencesManager.applySavedLookAndFeel(); SwingUtilities.invokeLater(() -> { HomeFrame homeFrame = new HomeFrame("TestUser"); homeFrame.setVisible(true); }); } } package com.quizsystem.ui.listeners; /** * Listener interface for notifications about quiz creation events. */ public interface QuizCreationListener { /** * Called when a new quiz has been successfully created and saved. */ void quizCreated(); } package com.quizsystem.util; import com.quizsystem.dao.QuizDao; // Assuming QuizDao exists import java.security.SecureRandom; import java.sql.SQLException; public class QuizCodeGenerator { private static final String ALPHANUMERIC = "ABCDEFGHIJKLMNOPQRSTUVWXYZ0123456789"; private static final int CODE_LENGTH = 6; // Adjust length as needed private static final SecureRandom random = new SecureRandom(); private static final int MAX_ATTEMPTS = 10; // Prevent infinite loops /** * Generates a unique alphanumeric quiz code. * Checks against the database using the provided DAO to ensure uniqueness. * * @param quizDao DAO to check for code existence. * @return A unique quiz code. * @throws SQLException if a database error occurs during checking. * @throws RuntimeException if a unique code cannot be generated after MAX_ATTEMPTS. */ public static String generateUniqueCode(QuizDao quizDao) throws SQLException { int attempts = 0; while (attempts < MAX_ATTEMPTS) { String code = generateRandomCode(CODE_LENGTH); if (!quizDao.quizCodeExists(code)) { return code; // Found unique code } System.out.println("Quiz code collision detected (" + code + "), retrying..."); // Debugging attempts++; } // If we reach here, we failed to find a unique code after several tries throw new RuntimeException("Failed to generate a unique quiz code after " + MAX_ATTEMPTS + " attempts."); } private static String generateRandomCode(int length) { StringBuilder sb = new StringBuilder(length); for (int i = 0; i < length; i++) { sb.append(ALPHANUMERIC.charAt(random.nextInt(ALPHANUMERIC.length()))); } return sb.toString(); } } **Explanation and Key Changes:** 1. **`QuizCreationListener`:** A simple interface is defined to decouple `QuizCreatorFrame` from `HomeFrame`. 2. **`HomeFrame` Implements Listener:** `HomeFrame` now implements `QuizCreationListener` and its `quizCreated()` method. This method simply calls `loadQuizzes()` to refresh the list. 3. **`QuizCreatorFrame` Constructor:** Takes a `QuizCreationListener` as an argument and stores it. 4. **Opening `QuizCreatorFrame`:** In `HomeFrame`, when the "Create a Quiz" menu item is clicked, `this` (the `HomeFrame` instance) is passed as the listener to the `QuizCreatorFrame` constructor. 5. **`QuizCreatorFrame.saveQuiz()`:** * Uses `SwingWorker` for the database operations (code generation and saving). * Calls `QuizCodeGenerator.generateUniqueCode()` to get a unique code. * Creates the `Quiz` object, including the generated code. * Calls `quizDao.saveQuizWithQuestions()`. * In the `done()` method of the `SwingWorker`, if saving was successful (`get()` returns true): * It calls `listener.quizCreated()` to notify `HomeFrame`. * It shows a success message including the generated quiz code. * It closes itself (`dispose()`). 6. **`QuizDao`:** * `saveQuizWithQuestions`: Implements the transactional logic to insert the quiz (with code) and then its questions. Uses batch updates for questions. Returns the generated quiz ID. * `quizCodeExists`: Checks if a code is already in use. * `findAllQuizzes`: Added to fetch all quizzes (make sure it selects `quiz_code`). 7. **`HomeFrame.loadQuizzes()`:** Now uses `quizDao.findAllQuizzes()` to get the data. 8. **`HomeFrame.QuizListRenderer`:** Updated to display the `quiz_code` alongside the title. 9. **Participant Counts:** As noted, this part is *not* implemented as it requires substantial additional backend infrastructure (session/attempt tracking). The renderer includes commented-out placeholders where this info *could* go if the data were available. Remember to: * Have the actual `QuizDao`, `Quiz`, `Question`, `DatabaseManager` implementations ready. * Ensure your database schema matches (especially the `quiz_code` column in `quizzes`). * Run `DatabaseManager.initializeDatabase()` if you added the `quiz_code` column.