Use of JInternalFrame in populated JFrame?

Question

Hi,
For my application I'm working on a simple Help screen (I do not want to use JavaHelp). The help screen I have developed is based on a JInternalFrame. This help screen is to be filled with HTML formatted text, that I load at start up. The loading of the text file works fine.
The application displays everything in a JFrame. When request the helpscreen is also to be displayed.
At start up I only display a JPanel taking up only (the middle) part of the JFrame. When I request the help screen, it is displayed to the right of the JPanel.
When I request the help screen when my JFrame has content, it is not shown. Would you know why that is? Does the help screen have to compete for screen space, and failing in it? Should I use something of an Z-order to get my Help screen to be displayed over the other content of the JFrame?
Abel
The following (non compilable code, it contains errors :-( ) might show what I'm trying to do:
import java.awt.*;
import java.awt.event.*;
import java.io.IOException;
import javax.swing.*;
public class HelpScreenPlace extends JFrame implements ActionListener {
     static HelpScreenPlace helpScreenPlace;
     static JMenuBar menuBar;
     static JMenu menu;
     static JMenuItem hMenuItem;
     static JInternalFrame helpFrame;
     static JEditorPane editorScrollPane;
     static int WIDTH = 450;
     static int HEIGHT = 350;
     static JTextField userNameField;
     static JLabel unameLabel = new JLabel("Username: ", SwingConstants.RIGHT);
     static JTextField passwordField;
     static JLabel passLabel = new JLabel("Password: ", SwingConstants.RIGHT);
     public HelpScreenPlace () {
          super("HelpScreenPlace");
          menuBar = new JMenuBar();
          menu = new JMenu ("Help");
          menu.setMnemonic(KeyEvent.VK_H);
          menu.getAccessibleContext().setAccessibleDescription("Help menu");
          menuBar.add(menu);          
          // The help contents functionality
          // TODO help functionality
          hMenuItem = new JMenuItem ("Help Contents");
          hMenuItem.setMnemonic(KeyEvent.VK_H);
          // What to do to get the keyboard shortcut F1 (no ALTMASK and the like)?
          hMenuItem.addActionListener(this);
          menu.add(hMenuItem);
          add(menuBar);
     public static void createAndShowGUI() {
          helpScreenPlace = new HelpScreenPlace();
          // Add a login panel (without functionality
          JPanel logInPanel = new JPanel();
          logInPanel.setLayout(new GridLayout (3, 2)); // 3 rows, 2 columns
          logInPanel.setBounds (WIDTH, HEIGHT, WIDTH, HEIGHT);
          userNameField = new JTextField ("jdoe", 10);
          passwordField = new JPasswordField("unanimous_unite", 10);
          logInPanel.add (unameLabel);
          logInPanel.add (userNameField);
          logInPanel.add(passLabel);
          logInPanel.add(passwordField);
          JComponent okButton = createButtonPanel();
          logInPanel.add(okButton);
          // An empty panel to fill up the empty spot after the button
          JPanel emptyPanel = new JPanel();
          emptyPanel.setBackground(Color.WHITE);
          logInPanel.add(emptyPanel);
          logInPanel.setSize(WIDTH, HEIGHT);
          logInPanel.setVisible (true);
     static JComponent createButtonPanel() {
          JPanel panel = new JPanel(new GridLayout(0,1));
          JButton okButton = new JButton("OK");
          okButton.setActionCommand("OK");
          // okButton.addActionListener(this); // Cannot use this in static reference (1st error)
          panel.add(okButton);
          return panel;
     public void actionPerformed (ActionEvent event) {
          String message = event.getActionCommand();
          if (message.equals("Help Contents")) {
               helpFrame = new HelpFrame(); //  cannot convert from HelpScreenPlace.HelpFrame to JInternalFrame (2nd error)
               helpFrame.setVisible(true);
               add(helpFrame);
     public static void main(String[] args) {
          javax.swing.SwingUtilities.invokeLater(new Runnable() {
               public void run() {
                    createAndShowGUI();
     private class CloseListener extends WindowAdapter {
          public void windowClosing (WindowEvent we) {
               System.exit(0);
        // - Syntax error on token "class", invalid Type
     // - Syntax error on token "extends", throws expected (etc on errors)
     private static class HelpFrame() extends JInternalFrame {
          super ("Help",
                    true,          // HelpFrame is resizable
                    true,          // HelpFrame is closable
                    true,          // HelpFrame is maximixable
                    true);          // HelpFrame is iconifiable
          // Get the helpPane from the model
          helpPane = model.getHelpPane();
          helpPane.setBackground(Color.WHITE);
          // Add helpPane to JScrollPane
          JEditorPane editorPane = getHelpPane();
          JScrollPane editorScrollPane = new JScrollPane(editorPane);
          editorScrollPane.setVerticalScrollBarPolicy(
                    JScrollPane.VERTICAL_SCROLLBAR_ALWAYS);
          editorScrollPane.setSize(250, 500);
          // editorScrollPane.setPreferredSize(new Dimension(250, 500));
          editorScrollPane.setMinimumSize(new Dimension(10, 10));
          add(editorScrollPane);
     JEditorPane getHelpPane() {
          JEditorPane pane = new JEditorPane();
          pane.setEditable(false); // Not editable
          java.net.URL helpURL = HelpFrame.class.getResource("HelpWindow.html");
          if (helpURL != null) {
               try {
                    System.out.println ("Getting help file " + helpURL);
                    pane.setPage(helpURL);
               } catch (IOException e) {
                    System.out.println ("Attempted to read a bad URL: " + helpURL);
          } else {
               System.out.println ("Couldn't find file: HelpWindow.html");
          return pane;
}For what it's worth, this is the HelpWindow.html file:
<html>
<body>
This is the help file for this project.<p>
<p>
<p>
<p>
<p>
<p>
<p>
<p>
</body>
</html>

Answer 1

JInternalFrame's are meant to live in JDesktopPanes. Of course, they dont' strickly have to, but you aren't going to get it to act properly like an internal frame without jumping thru a lot of hoops. At least try packing or setting the size of the internal frame when you add it. If your layout is a border layout, then you're probably replacing the contents of the frame. And anyway, I don't see in your code where you are actually adding the main UI to the frame in the first place.
Of course, you can wrap your whole UI in a JDesktopPane so that the main display is a panel filling the whole desktop pane on a layer, then add the help frame in there on a higher layer.
Or maybe just not worry about internal frames and use a JDialog or another JFrame instead.
Edited by: bsampieri on Apr 15, 2008 10:57 AM