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How to keep a component in the background window stay in focus?

In my program, I have this MAIN window and a HELP window. The HELP window (when opened) is to always stay on top whether it's in focus or not. The issue however is, when I try to requestFocusInWindow() for a component in the MAIN window through an action listener that gets fired from the HELP window, it just won't let me do it.
What is the proper way of accomplishing this?
TY :)
Edit:
As requested, here's a short example of what I'm trying to accomplish. Essentially I need the button inside the HELP window to trigger focus to the TextField inside the Main window.
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
public class Main {
public static void initGUI() {
mainFrame = new JFrame("Main");
helpFrame = new JFrame("Help");
mainFrame.setPreferredSize(new Dimension(500, 200));
helpFrame.setPreferredSize(new Dimension(500, 200));
mainFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
helpFrame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
mainFrame.setLayout(new FlowLayout());
helpFrame.setLayout(new FlowLayout());
mainTextView = new JTextField("", 20);
mainButton = new JButton("Open Help");
helpButton = new JButton("Request Focus");
mainButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource().equals(mainButton)) {
helpFrame.pack();
helpFrame.setVisible(true);
}
}
});
helpButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource().equals(helpButton))
System.out.println("Focus requested:" + mainTextView.requestFocusInWindow());
}
});
helpFrame.add(helpButton);
mainFrame.add(mainTextView);
mainFrame.add(mainButton);
mainFrame.pack();
mainFrame.setVisible(true);
}
public static void main(String[] args) {
initGUI();
}
static JFrame mainFrame, helpFrame;
static JTextField mainTextView;
static JButton mainButton, helpButton;
}

So turns out the fix was rather trivial. If requestFocus() is used instead of requestFocusInWindow(), it seems to work just fine.
Kinda feel stupid for how much time I spent on this :P
helpButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
if (e.getSource().equals(helpButton))
mainTextView.requestFocus();
}
});

addKeylistener() not working

For school I have to make a small game which is based on Breakout.
I got my JFrame which does this:
game.setFocusable(true);
setContentpane(game);
in my game I am adding a inputhandler which extends Keylistener and implements JPanel.
setFocusable(true);
Inputhandler input = new Inputhandler();
addKeylistener(input);
It just doesn't seem to work, I've been writing a lot of tests but I can't see to get the input handle capture any keyPressed.
When I change my JFrame to:
add(game);
it works like it is meant to work but the problem I encounter when doing this way is painting my panels the correct way. I'm kinda stuck on this issue so please someone help me out.
Point I've reached now:
public Game(){
setFocusable(true);
requestFocus();
requestFocusInWindow();
getInputMap().put(KeyStroke.getKeyStroke("SPACE"), "pressed");
getActionMap().put("pressed", new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("Space is pressed");
}
});
this.inputHandler = new InputHandler();
addKeyListener(this.inputHandler);
setPreferredSize(new Dimension(500,500));
}

If I had a dollar for every time this question were asked, I'd retire rich. As per previous similar questions...
Yes you would need to make the JPanel focusable for its KeyListener to work
And you'd also have to give it the focus, since being focusable is not enough. Usually this is achieved by calling requestFocusInWindow() on the listened to JPanel.
And nothing else can have the focus or steal the focus if the KeyListener is to continue functioning.
Which is one of several reasons why most of us recommend against use of KeyListeners for Swing applications
And usually in favor of using Key Bindings.
Edit
I've used your code and it works, both the key bindings and the KeyListener:
import java.awt.Dimension;
import java.awt.event.*;
import javax.swing.*;
public class Game extends JPanel {
private InputHandler inputHandler;
public Game() {
setFocusable(true);
requestFocus();
requestFocusInWindow();
getInputMap().put(KeyStroke.getKeyStroke("SPACE"), "pressed");
getActionMap().put("pressed", new AbstractAction() {
#Override
public void actionPerformed(ActionEvent e) {
System.out.println("Space is pressed");
}
});
this.inputHandler = new InputHandler();
addKeyListener(this.inputHandler);
setPreferredSize(new Dimension(500, 500));
}
class InputHandler extends KeyAdapter {
#Override
public void keyPressed(KeyEvent e) {
System.out.println("key pressed");
}
#Override
public void keyReleased(KeyEvent e) {
System.out.println("key released");
}
}
private static void createAndShowGui() {
Game mainPanel = new Game();
JFrame frame = new JFrame("Game");
frame.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
frame.getContentPane().add(mainPanel);
frame.pack();
frame.setLocationByPlatform(true);
frame.setVisible(true);
}
public static void main(String[] args) {
SwingUtilities.invokeLater(new Runnable() {
public void run() {
createAndShowGui();
}
});
}
}

Need advice on creating a closing button for a small Java program

I am a novice as already stated and looking to create a button to close the program out. I am not talking about making sure the typical window close (Red X) terminates the program. I wish to make an additional button within my frame that when clicked will terminate the program as well.

You can add an ActionListener to your button which, upon action being performed, exits from the JVM.
yourButton.addActionListener(new ActionListener() {
#Override
public void actionPerformed(ActionEvent e) {
System.exit(0);
}
});

If you have set up the main application frame's (JFrame) defaultCloseOperation to JFrame.EXIT_ON_CLOSE then simply calling the frame's dispose method will terminate the program.
JButton closeButton = JButton("Close");
closeButton.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
yourReferenceToTheMainFrame.dispose();
}
});
If not, then you will need to add to the actionPerformed method a call to System.exit(0);

import java.awt.GridLayout;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.EmptyBorder;
public class GoodbyeWorld {
GoodbyeWorld() {
final JFrame f = new JFrame("Close Me!");
// If there are no non-daemon threads running,
// disposing of this frame will end the JRE.
f.setDefaultCloseOperation(JFrame.DISPOSE_ON_CLOSE);
// If there ARE non-daemon threads running,
// they should be shut down gracefully. :)
JButton b = new JButton("Close!");
JPanel p = new JPanel(new GridLayout());
p.setBorder(new EmptyBorder(10,40,10,40));
p.add(b);
f.setContentPane(p);
f.pack();
f.setLocationByPlatform(true);
f.setVisible(true);
ActionListener closeListener = new ActionListener(){
#Override
public void actionPerformed(ActionEvent arg0) {
f.setVisible(false);
f.dispose();
}
};
b.addActionListener(closeListener);
}
public static void main(String[] args) {
Runnable r = new Runnable() {
#Override
public void run() {
new GoodbyeWorld();
}
};
SwingUtilities.invokeLater(r);
}
}

If you are extending the org.jdesktop.application.Application class (Netbeans would do that) you could invoke exit() in your app class, so:
button.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent evt) {
yourApp.exit();
}
});

Java TextField getText() returns previous string value

I have a problem with Java Textfield that is when I cover all text in the JTextField and input new text immediately(do not pass backspace) into the JTextField, then I use function getText() I get the previous string not current string. Please help for some solutions. Thanks in advance.

I just tested the problem you described by adding a keyListener to a JTextField and printing the getText() method's return value to the console.
What I found out is that it is always one character behind if you want to use the getText() method right in the keyTyped or keyPressed event (I didn't know this because I usually just use a button to confirm I'm done entering the text and bind a KeyEvent to the Return key to trigger the button if a user wants to confirm by hitting enter)
I think this is due to the textField updating its text value AFTER the event is shot.
I assume this is what you did since you didn't provide sample code, so I'll delete this answer if it's not.
The work around to this is to implement what you want to do in the keyReleased method instead.
public void keyReleased(Event e)
{
System.out.println(myTextField.getText());
}

Don't use a KeyListener. The character has NOT been added to the Document when the keyPressed() event is fired.
Add an ActionListener to a JButton. This way the user clicks on the button when text is finised being entered.
Also, in the future post a SSCCE with you question so we can better understand what you are trying to do.

for example :
import java.awt.GridLayout;
import javax.swing.*;
import javax.swing.event.DocumentEvent;
import javax.swing.event.DocumentListener;
public class TextLabelMirror {
private JPanel mainPanel = new JPanel();
private JTextField field = new JTextField(20);
private JTextField field1 = new JTextField(20);
public TextLabelMirror() {
field.getDocument().addDocumentListener(new DocumentListener() {
#Override
public void changedUpdate(DocumentEvent e) {
updateLabel(e);
}
#Override
public void insertUpdate(DocumentEvent e) {
updateLabel(e);
}
#Override
public void removeUpdate(DocumentEvent e) {
updateLabel(e);
}
private void updateLabel(DocumentEvent e) {
java.awt.EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
field1.setText(field.getText());
}
});
}
});
mainPanel.setLayout(new GridLayout(1, 0, 10, 0));
mainPanel.add(field);
mainPanel.add(field1);
}
public JComponent getComponent() {
return mainPanel;
}
private static void createAndShowUI() {
JFrame frame = new JFrame("TextLabelMirror");
frame.getContentPane().add(new TextLabelMirror().getComponent());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
#Override
public void run() {
createAndShowUI();
}
});
}
}

One JFrame opening another

I have a JFrame and JPanel full of Jsomethings with an actionlistener. When the user clicks an object I want to open another JFrame. Here is what I did:
public void actionPerformed(ActionEvent e) {
Object source = e.getSource();
if (source == rejectionbutton){
RejectApp ra = new RejectApp();
ra.main(null);
}
}
(RejectApp calls a new JFrame.) So another JFrame opens on the screen with more options. It works OK (so far), but I want to know is this standard? I mean calling the main method like this?
Another question is, without using a cardlayout (which I don't want to use), is the best way to handle multiple panels, by doing this sort of thing?

I would change a few things. First off, usually an application has one JFrame and then if it needs to show another window does so as a modal or non-modal dialog such as can be obtained with a JDialog or JOptionPane. Having said that, it's even more common to have one JFrame and swap "views" in the JFrame -- swap contentPanes or other large panels via a CardLayout as this would mimic the behavior of many gui programs we all currently use.
Personally, I also try to gear my GUI creation towards creating a JPanel or JComponent rather than towards creating a top-level window. This way if I want to display the GUI as a stand alone app, a dialog, or an applet I can pop it into the contentPane of a JFrame or JDialog or JApplet respectively, or if as an inner panel of a more complex GUI, then insert it there, or in an application with a swapping view, then as a card in a CardLayout as noted above. The bottom line is I feel that this structure gives you the developer a lot more options in how you can use this GUI.
Also, I would avoid calling another class's main as you're doing (assuming this is the public static void main method) as you lose all benefits of OOPs. You also seem to be trying to call a static method in a non-static way (assuming I understand your program structure correctly).
For your second question, it begs a question of my own: why do you not want to use CardLayout?
edit: an example of what I meant is as follows:
import java.awt.Dimension;
import java.awt.Window;
import java.awt.Dialog.ModalityType;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import javax.swing.*;
public class SwingEg {
private static void createAndShowUI() {
JFrame frame = new JFrame("Main JFrame");
frame.getContentPane().add(new MainGUI().getMainPanel());
frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
frame.pack();
frame.setLocationRelativeTo(null);
frame.setVisible(true);
}
public static void main(String[] args) {
java.awt.EventQueue.invokeLater(new Runnable() {
public void run() {
createAndShowUI();
}
});
}
}
class MainGUI {
private static final Dimension MAIN_PANEL_SIZE = new Dimension(450, 300);
private JPanel mainPanel = new JPanel();
private JDialog modalDialog;
private JDialog nonModalDialog;
public MainGUI() {
JButton openModalDialogBtn = new JButton("Open Modal Dialog Window");
openModalDialogBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
openModalDialogBtnActionPerformed(e);
}
});
JButton openNonModalDialogBtn = new JButton("Open Non-Modal Dialog Window");
openNonModalDialogBtn.addActionListener(new ActionListener() {
public void actionPerformed(ActionEvent e) {
openNonModalDialogBtnActionPerformed(e);
}
});
mainPanel.setPreferredSize(MAIN_PANEL_SIZE);
mainPanel.add(openModalDialogBtn);
mainPanel.add(openNonModalDialogBtn);
}
private void openModalDialogBtnActionPerformed(ActionEvent e) {
if (modalDialog == null) {
Window topWindow = SwingUtilities.getWindowAncestor(mainPanel);
modalDialog = new JDialog(topWindow, "Modal Dialog", ModalityType.APPLICATION_MODAL);
modalDialog.getContentPane().add(new DialogPanel().getMainPanel());
modalDialog.pack();
modalDialog.setLocationRelativeTo(topWindow);
modalDialog.setVisible(true);
} else {
modalDialog.setVisible(true);
}
}
private void openNonModalDialogBtnActionPerformed(ActionEvent e) {
if (nonModalDialog == null) {
Window topWindow = SwingUtilities.getWindowAncestor(mainPanel);
nonModalDialog = new JDialog(topWindow, "Non-Modal Dialog", ModalityType.MODELESS);
nonModalDialog.getContentPane().add(new DialogPanel().getMainPanel());
nonModalDialog.pack();
nonModalDialog.setLocationRelativeTo(topWindow);
nonModalDialog.setVisible(true);
} else {
nonModalDialog.setVisible(true);
}
}
public JPanel getMainPanel() {
return mainPanel;
}
}
class DialogPanel {
private static final Dimension DIALOG_SIZE = new Dimension(300, 200);
private JPanel dialogPanel = new JPanel();
public DialogPanel() {
dialogPanel.add(new JLabel("Hello from a dialog", SwingConstants.CENTER));
dialogPanel.setPreferredSize(DIALOG_SIZE);
}
public JPanel getMainPanel() {
return dialogPanel;
}
}

I would rather make a new instance of JFrame or a subclass, or call a new method who makes a new JFrame:
public void actionPerformed(ActionEvent e) {
Object source = e.getSource();
if (source == rejectionbutton){
JFrame frame = new JFrame("New Frame");
//or
makeNewFrame();
}
}
Another simple Layout-Manager is the BorderLayout, it´s the default Layout-Manager of the JFrame class.

new YourJFrameNameHere().setVisible(true);
Replace YourJFrameNameHere with the JFrame name.
Simple, no?