Question

im using java swing for my coursework to make a quiz. Below is my main frame class which makes new panels which i have as separate classes. But for example if i have a login panel, and the user hits the login button how can i signal my main tabbedquiz class that someone has logged in?

public class TabbedQuiz {

private JFrame jF;
private JTabbedPane tP;
public static void main(String[] args) {
    EventQueue.invokeLater(new Runnable() {
        public void run() {
            try {
                TabbedQuiz w = new TabbedQuiz();
                w.jF.setVisible(true);
            } catch (Exception e) {
                e.printStackTrace();
            }
        }

    });
}


public TabbedQuiz() {
    initialize();
}


private void initialize() {
    tp= new JFrame();
    tp.setTitle("welcome to ...");
    final JPanel mainPanel= new JPanel();
    final JPanel anotherPanel= new JPanel();
    final JPanel examplePanel = new JPanel();
    final JPanel quizPanel = new JPanel();
    final JPanel examPanel = new JPanel();
    final JPanel viewPerfPanel = new JPanel();
    final JPanel settingsPanel = new JPanel();

//set up the panels

    tF.setBounds(100, 100, 764, 470);
    tF.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
    tF.getContentPane().setLayout(null);

    tabbedPane = new JTabbedPane(JTabbedPane.TOP);
    tabbedPane.setBounds(10, 11, 728, 410);
    tF.getContentPane().add(tabbedPane);

    tabbedPane.addTab("Welcome", null, mainPanel, null);

// set up other tabs

Answer 1

If your goal is to prevent access to the quiz until someone has logged in, hide other panels or frames until a user has logged in.

Here’s an example using CardLayout:

final JPanel mainPanel = new JPanel(new CardLayout());
final JTextField textField = new JTextField(10);

Action action = new AbstractAction("Login") {
    public void actionPerformed(ActionEvent e) {
        /* Check user credentials here. */
        boolean b = textField.getText().equals("true");

        CardLayout cl = (CardLayout)(mainPanel.getLayout());
        cl.show(mainPanel, b ? e.getActionCommand() : "login");
    }
};

JButton loginButton = new JButton(action);
loginButton.setActionCommand("quiz");

JPanel loginPanel = new JPanel();
loginPanel.add(textField);
loginPanel.add(loginButton);

JPanel quizPanel = new JPanel();
quizPanel.add(new JLabel("Quiz"));

mainPanel.add(loginPanel, "login");
mainPanel.add(quizPanel, "quiz");

JFrame f = new JFrame();
f.setContentPane(mainPanel);
f.pack();
f.setVisible(true);
f.addWindowListener(new WindowAdapter() {
    public void windowClosing(WindowEvent e) {
        System.exit(0);
    }
});