🚀 go-pugleaf

Hi there,

I am trying to have a swing based applet that have multiple panels.

In my sample, the first panel have a button that will call the parent
JApplet
to switch to the second panel.

I also want to be able to switch to the corresponding panel based on
what
the user select from the menu.

When I run the application under appletviewer, I managed to change
from the first panel to the second panel.

But after that, it doesn't work any more.

Enclosed along is the full source code of my application in 3 java
files.

Any help is highly appreciated.

Thanks,
Yong Chee Keong


/* ***************************
 Source code for SampleApplet
 *****************************
*/


import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import com.sun.java.swing.*;

//import com.sun.java.swing.UIManager;
public class SampleApplet extends JApplet implements ActionListener {
  boolean isStandalone = false;

  panel1 first;
  panel2 second;
  Frame browserFrame;
  JMenuBar menuBar;
  JMenu menu, submenu;
  JMenuItem menuItem;
  JPanel activepane;

    //Labels to identify the text fields

  public SampleApplet() {
  }
//Initialize the applet

  public void init() {

    Component comp = this;
    while (!(comp instanceof Frame) )
     comp = comp.getParent();

    browserFrame = (Frame) comp;

    try {
    jbInit();
    }
    catch (Exception e) {
    e.printStackTrace();
    }
  }

//Component initialization

  private void jbInit() throws Exception {
    menuBar = new JMenuBar();
    setJMenuBar(menuBar);

    menu = new JMenu("A Menu");
    menuBar.add(menu);

    menuItem = new JMenuItem("Item One");
    menuItem.addActionListener(this);
    menu.add(menuItem);
    menuItem = new JMenuItem("Item Two");
    menuItem.addActionListener(this);
    menu.add(menuItem);

    menu = new JMenu("Another Menu");
    menuBar.add(menu);

    first = new panel1(this);
    second = new panel2(this);


    activepane = first;

    this.getContentPane().add(activepane);

    browserFrame.pack();
    this.setSize(400,300);

  }
//Start the applet

  public void start() {
  }
//Stop the applet

  public void stop() {
  }
//Destroy the applet

  public void destroy() {
  }

  public void actionPerformed (ActionEvent e) {
        JMenuItem source = (JMenuItem)(e.getSource());
        String s = source.getText();
        System.out.println("Action Event is " + s);

        if (s == "Item One") {
            switchpanel("first");
           }
        else if (s == "Item Two") {
            switchpanel("second");
        }
  }

  public void switchpanel(String args) {

     this.getContentPane().remove(activepane);
     System.out.println("Args is " + args);
        if (args == "second") {
            activepane = second;
           }
        else if (args == "first") {
            activepane = first;
        }

    this.getContentPane().add(activepane);
    browserFrame.pack();
    this.setSize(400,300);

  }

}


/* **********************
 Source code for panel2
 ************************
*/


import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import com.sun.java.swing.*;

//import com.sun.java.swing.UIManager;
public class panel1 extends JPanel {

    //Labels to identify the text fields
     private JLabel amountLabel;
     private JLabel rateLabel;
     private JLabel numPeriodsLabel;
     private JLabel paymentLabel;
     private JLabel dateLabel;
     private JLabel icLabel;

     //Strings for the labels
     private static String amountString = "Loan Amount: ";
     private static String rateString = "APR: ";
     private static String numPeriodsString = "Years: ";
     private static String paymentString = "Monthly Payment: ";
     private static String dateString = "Date: ";
     private static String icString = "I.C. No: ";

     SampleApplet theapplet = null;
     JButton bc = new JButton("Next");

  //Construct the applet

  public panel1() {
  }

  public panel1(SampleApplet applet) {
        theapplet = applet;
        init();
  }


//Initialize the applet

  public void init() {

    try {
    jbInit();
    }
    catch (Exception e) {
    e.printStackTrace();
    }
  }

  private void jbInit() throws Exception {

    this.setLayout(new GridLayout(0,2));


    amountLabel = new JLabel(amountString);
    rateLabel = new JLabel(rateString);
    numPeriodsLabel = new JLabel(numPeriodsString);
    paymentLabel = new JLabel(paymentString);
    dateLabel = new JLabel(dateString);
    icLabel = new JLabel(icString);

    this.add(amountLabel);
    this.add(rateLabel);
    this.add(numPeriodsLabel);
    this.add(dateLabel);
    this.add(icLabel);
    bc.addActionListener(new bc_adapter(this));
    this.add(bc);
  }
//Start the applet

  public void start() {
  }
//Stop the applet

  public void stop() {
  }
//Destroy the applet

  public void destroy() {
  }
  void bc_actionPerformed(ActionEvent e) {
        if (theapplet != null)
           theapplet.switchpanel("second");
  }

  class bc_adapter implements java.awt.event.ActionListener {

      panel1 adaptee;

      bc_adapter(panel1 adaptee) {
        this.adaptee = adaptee;
      }

      public void actionPerformed(ActionEvent e) {
        adaptee.bc_actionPerformed(e);
      }
  }

}



/* **********************
 Source code for panel2
 ************************
*/

import java.awt.*;
import java.awt.event.*;
import java.applet.*;
import com.sun.java.swing.*;

//import com.sun.java.swing.UIManager;
public class panel2 extends JPanel {

    //Labels to identify the text fields
     private JLabel amountLabel;
     private JLabel rateLabel;
     private JLabel numPeriodsLabel;
     private JLabel paymentLabel;
     private JLabel dateLabel;
     private JLabel icLabel;

     //Strings for the labels
     private static String amountString = "Name: ";
     private static String rateString = "Computer Model: ";
     private static String numPeriodsString = "Salary: ";
     private static String paymentString = "Status: ";
     private static String dateString = "Position: ";
     private static String icString = "Info: ";

     SampleApplet theapplet = null;
     JButton bc = new JButton("Back");

  //Construct the applet

  public panel2() {
  }

  public panel2(SampleApplet applet) {
        theapplet = applet;
        init();
  }


//Initialize the applet

  public void init() {

    try {
    jbInit();
    }
    catch (Exception e) {
    e.printStackTrace();
    }
  }

  private void jbInit() throws Exception {

    this.setLayout(new GridLayout(0,2));


    amountLabel = new JLabel(amountString);
    rateLabel = new JLabel(rateString);
    numPeriodsLabel = new JLabel(numPeriodsString);
    paymentLabel = new JLabel(paymentString);
    dateLabel = new JLabel(dateString);
    icLabel = new JLabel(icString);

    this.add(amountLabel);
    this.add(rateLabel);
    this.add(numPeriodsLabel);
    this.add(dateLabel);
    this.add(icLabel);
    bc.addActionListener(new bc_adapter(this));
    this.add(bc);
  }
//Start the applet

  public void start() {
  }
//Stop the applet

  public void stop() {
  }
//Destroy the applet

  public void destroy() {
  }
  void bc_actionPerformed(ActionEvent e) {
        if (theapplet != null)
           theapplet.switchpanel("first");
  }

  class bc_adapter implements java.awt.event.ActionListener {

      panel2 adaptee;

      bc_adapter(panel2 adaptee) {
        this.adaptee = adaptee;
      }

      public void actionPerformed(ActionEvent e) {
        adaptee.bc_actionPerformed(e);
      }
  }

}