How to use put Obsever Patterns in JTabbedPane layout

Question

Hi, I am trying to put Observer Patterns in a JTabbedPane layout so that my program can pass event data to other class. But I don't know how I can accomplish this. Could someone help me?
Thanks,
Joanna
import javax.swing.*;
public class Restaurant {
     public static void main(String[] args) {
          JFrame frame = new JFrame("168 Restaurant");
          frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
          JTabbedPane tp = new JTabbedPane();
          pizzaPanel pPanel = new pizzaPanel(); // create pizzaPanel class
          tp.addTab("Order", pPanel);
          double total; String result;
          total = pPanel.getTotal();                       //get total price and order from pizzaPanel class
          result = pPanel.getPizza();
          pricePanel price = new pricePanel(total, result);       //pass to pricePanel class
          tp.addTab("Payment", price);
          frame.getContentPane().add(tp);
          frame.pack();
          frame.setVisible(true);
//pizzaPanel class
import java.awt.*;
import javax.swing.*;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
public class pizzaPanel extends JPanel {
     public double total = 0;
     public String order = " ";
     private JPanel titlePanel = new JPanel();
     private JPanel gridPanel = new JPanel();
     private JRadioButton cb1, cb2;
     private JButton submit;
     public pizzaPanel () {
          titlePanel.setPreferredSize(new Dimension(100, 30));
          titlePanel.setLayout(new FlowLayout());
          JLabel label = new JLabel("Please order your food");
          titlePanel.add(label);
          gridPanel.setLayout (new GridLayout(1, 4));
          JLabel b1 = new JLabel("Premium Goats' Cheese $5.00");
          cb1 = new JRadioButton ("1");cb2 = new JRadioButton ("2");
          submit = new JButton("Submit");
          submit.setPreferredSize(new Dimension(50, 20));
          ButtonListener listener = new ButtonListener();
          submit.addActionListener(listener);
          ButtonGroup bg1 = new ButtonGroup ();
          bg1.add(cb1);bg1.add(cb2);
          gridPanel.add(b1);gridPanel.add(cb1);gridPanel.add(cb2);
          setPreferredSize(new Dimension (200, 200));
          setLayout(new BorderLayout());
          add(titlePanel, BorderLayout.NORTH);
          add(gridPanel, BorderLayout.CENTER);
          add(submit, BorderLayout.SOUTH);
     public class ButtonListener implements ActionListener {
      public void actionPerformed(ActionEvent e) {
          if (cb1.isSelected()) {                                   
               total += 5;                         //total is obtained here
               order += "Goats' Cheese" + " \n";               //order is obtained here
         else if (cb2.isSelected()) {
               total += 10;                         //total is obtained here
               order += "Goats' Cheese" + " \n";                //order is obtained here
        if (e.getSource() == submit)
            JOptionPane.showMessageDialog (null, order  + "\t = $" + total + "\n Please click Payment tab");
     public double getTotal(){               //try to pass the total out
          return total;               
     public String getPizza(){                  //try to pass the order out
          return order;
//pricePanel class
import java.awt.*;
import javax.swing.*;
public class pricePanel extends JPanel {
     public pricePanel (double total, String order) {           //total and order are passed in
          setPreferredSize(new Dimension (300, 200));
          setBackground (Color.green);
          setLayout(new FlowLayout());
          JLabel l1 = new JLabel ("Please pay the amount: ");     
          JLabel l2 = new JLabel (order + ": \t $" + total);   //total & order don't hold values obtained from
                                    //pircePanel class.
          add(l1);add(l2);
}

Answer 1

Please don't double post. This is quite rude. I've a mind to delete my recent post in your other thread.