Giving focus to a JPanel

I need to give the keyboard focus to an object, myJPanel, that extends JPanel. Calling myJPanel.isFocusable returns true, but when I try to give that object the focus with myJPanel.requestFocusInWindow, that method returns false and focus isn't transferred. Anybody have some ideas on what I'm doing wrong?
Thanks in advance.
--Jay

Thanks for the help, both of you. What's driving me nuts is that the JPanel already is focusable, at least according to the isFocusable method. Code like this:
System.err.println(this.isFocusable());
this.setFocusable(true);
System.err.println(this.isFocusable());
System.err.println(this.requestFocusInWindow());
prints out "true true false false." Apparently it is possible to give my JFrame the focus, but I'm just not doing it correctly. Also, I did call addKeyListener, but this is my first time using KeyListeners and it's totally possible I screwed that up too. Regardless, if the JFrame that's supposed to be listening for KeyEvents doesn't have the focus, then it won't pick up those KeyEvents whether the listener is set correctly or not. (At least, that's my reading of the Java documentation.)
Anyway, thanks for your advice, and any more ideas would be totally appreciated.
--Jay

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Giving focus to a component

Hi all,
How does one give focus back or just plain giving focus to a JComponent
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This puzzles, me please help?

That method was introduced in 1.4, but the API recommends you use requestFocusInWindow()

Giving focus to the program

I need to make a Java program give focus to itself.
I'm thinking of a thread that would give focus to the program every second.
But I dont know how to make it "give focus to this program on the computer". With my searches, I can only find about giving focus to a component of the program, not the program in the computer/os
The program will run in Windows, so something platform specific would be ok.
Or any other way to make this Java program regain focus automatically about every second.

In brief, I need to do it for a barcode system. It's somewhat complicated, the commerce system uses php and is online. In this system, I added an applet which recieves events from a local program (the one I want to auto-focus).
This local program recieves events from the barcode scanner. But a barcode scanner is stupid, and considered like a keyboard for the computer, so a program must be in focus to recieve the events. The best solution I could think of is to make this local program always takes the focus. The interface of this program would be small (or no interface at al).
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The computer that will run it is the "cash regitster" computer for the store, so having this local program always gaining focus is correct. And if needed, this "auto-focus" could be deactivated while the computer is needed for other things.
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How to have focus in 2 JPanels on 1 JFrame?

Hey all..
Like i wrote in the subject, how can i do that?
I have 2 JPanels in 1 JFrame. 1 top JPanel and 1 buttom JPanel. I've a keylistener in top JPanel and a buttonslistener in buttom JPanel. When i press on the button on the buttom JPanel, then my keylistener wont trigger in the top JPanel.
Plz help.
Thx.

The whole point to window focus is to avoid this! There is at most one focused component per window.
As a rule of thumb, when someone uses a KeyListener, they're mistaken. You should be using key binding. This can make your focus problems go away, since you can choose to associate the keyStoke with the whole window, not just the focused component.
[http://java.sun.com/docs/books/tutorial/uiswing/misc/keybinding.html]

Detect Focus transfer between JPanels

I have an app that has a scrollpane containing a JPanel (A), that contains a bunch of JPanels (B) - each of which contains multiple controls, panels, etc....
I want to make sure that whichever JPanel (B) has the focus in it, and use the viewPort.scrollToVisible() to make sure that panel is fully displayed.
So far, the only way I've seen to do that is to add a FocusListener to each and every control and check to see which panel it's in.
BLECH!
Is there an easier way?
I'd really like some kind of listener that is just notified whenever focus transfers between the upper level Panels.

Thanks to all. Re-read those sections, and came up with this little utility class to do what I needed.
It listens for focus changes between panels, and notifies a listener of these changes.
import java.awt.Component;
import java.awt.KeyboardFocusManager;
import java.beans.PropertyChangeEvent;
import java.beans.PropertyChangeListener;
import java.util.ArrayList;
import javax.swing.JPanel;
* Tracks the focus for Panels. If the focus enters or leaves the panel (i.e. focus goes
* to/from any component in the panel, and from/to anything outside the panel)
* It notifies any listeners of the event.
* @author jlussmyer
public class PanelFocusTracker {
    /** Array of panels we are tracking focus changes for. */
    private JPanel[] panels = new JPanel[0];
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    private JPanel curFocus = null;
     * Constructor. Ties into focus handling system.
    public PanelFocusTracker() {
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        focusManager.addPropertyChangeListener(
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                    @Override
                    public void propertyChange(PropertyChangeEvent e) {
                        String prop = e.getPropertyName();
                        if (("focusOwner".equals(prop)) && ((e.getNewValue()) instanceof Component)) {
                            Component comp = (Component) e.getNewValue();
                            checkForPanelChange(comp);
        return;
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     * @param comp Component that is gaining focus.
    private void checkForPanelChange(Component comp) {
        JPanel gainPanel = getPanelForComponent(comp);
        if (gainPanel == curFocus) {
            return; // no change, nothing to do.
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            notifyListeners(curFocus, false); // This panel lost focus
        if (gainPanel != null) {
            notifyListeners(gainPanel, true); // This panel gained focus
        curFocus = gainPanel;
        return;
     * Finds which of the panels we are tracking contains the given component.
     * @param comp Component to find containing panel for
     * @return Containing Panel, null if it isn't in one of the panels being tracked.
    private JPanel getPanelForComponent(Component comp) {
        JPanel result = null;
        while ((comp != null) && (result == null)) {
            if (isBeingTracked(comp)) {
                result = (JPanel) comp;
            } else {
                comp = comp.getParent();
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     * Checks to see if this is one of the JPanels we are tracking.
     * @param comp Component to check
     * @return true if it's a JPanel that we are tracking.
    private boolean isBeingTracked(Component comp) {
        boolean result = false;
        for (int idx = 0; (idx < panels.length); idx++) {
            if (comp == panels[idx]) {
                result = true;
                break;
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     * changes.
     * @param panel Panel to track focus for.
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        // Don't allow the same panel to be added multiple times.
        for (int idx = 0; (idx < panels.length); idx++) {
            if (panel == panels[idx]) {
                panel = null;
                break;
        if (panel != null) {
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            System.arraycopy(panels, 0, temp, 0, panels.length);
            temp[panels.length] = panel;
            panels = temp;
        return;
     * Remove a panel from the list of panels being tracked for Panel Focus
     * changes.
     * @param panel Panel to stop tracking focus for.
     * @return true if panel was being tracked, false otherwise.
    public boolean removePanel(JPanel panel) {
        boolean found = false;
        for (int idx = 0; (idx < panels.length); idx++) {
            if (panel == panels[idx]) {
                found = true;
                JPanel[] temp = new JPanel[panels.length - 1];
                if (idx == 0) { // removing first entry
                    if (temp.length > 0) {
                        System.arraycopy(panels, 1, temp, 0, temp.length);
                } else if (idx == (panels.length - 1)) { // remove last entry
                    System.arraycopy(panels, 0, temp, 0, temp.length);
                } else { // Remove something in the middle
                    System.arraycopy(panels, 0, temp, 0, idx);
                    System.arraycopy(panels, idx + 1, temp, idx + 1, temp.length - idx);
                break;
        return found;
     * Remove all JPanels from focus tracking.
    public void removeAllPanels() {
        panels = new JPanel[0];
        curFocus = null;
        return;
     * Interface for listeners to be notified of focus being gained/lost by
     * any of the panels being tracked.
    public interface Listener {
        /** Focus Lost by given panel */
        void panelFocusLost(JPanel panel);
        /** Focus gained by given panel */
        void panelFocusGained(JPanel panel);
    /** Listeners to be notified of Panel Focus changes */
    private ArrayList<Listener> focusListeners = new ArrayList<Listener>();
     * Add a listener to be notified of changes to the Focus for any Panel
     * being tracked.
     * @param listener Listener to be notified for Panel Focus changes.
    public void addListener(Listener listener) {
        focusListeners.add(listener);
        return;
     * Remove a Panel Focus listener.
     * @param listener listener to no longer be notified of Focus changes.
     * @return true if listener found, false otherwise.
    public boolean removeListener(Listener listener) {
        return focusListeners.remove(listener);
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     * @param panel panel that gained/lost focus.
     * @param gained true if focus gained, false if focus lost.
    private void notifyListeners(JPanel panel, boolean gained) {
        Listener[] list = focusListeners.toArray(new Listener[focusListeners.size()]);
        for (int idx = 0; (idx < list.length); idx++) {
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                list[idx].panelFocusGained(panel);
            } else {
                list[idx].panelFocusLost(panel);
        return;
}

Giving "focus" to a folder in Mail: only with the keyboard?

Hello everybody,
I've found that in Mail, you can choose a folder with the mouse, but that you cannot activate it, you cannot give it the focus.
When you click on a folder, it becomes pale blue and the arrow keys do not allow to go from one folder to the other. The focus is in the mails pane.
The only way to give the focus to a folder is through the keyboard, using Shift-Tab (or Tab several times): the folder then becomes dark blue, it "has the focus", and the arrow keys allow to go from one folder to the other, or to open and close folders.
This is an interface issue, and is highly unusual. Am I the only one to observe this?
If I am the only one, then I have a bug somewhere. If not, Mail has an interface problem that I will report to Apple, hoping for the best.
Thanks for your input, and Cheers!
Roger the Photographer
G5 1.8Dual, 2GB RAM Mac OS X (10.4.8) 20" App Dsplay, ext. Lacie, iPod, Bach on Al-Lansing, Canon 5D, Canon L glass

Hello Roger.
What you’ve described is exactly how it works.
Although I agree that this is non-standard behavior,
I have the feeling that it’s intentional, not a bug.
There are other situations in Mail where the view
that handles the keystrokes is what the user is most
likely to want rather than what has focus.
If you have the preview pane visible, for example,
and the view that has focus is the message list, the
arrow keys let you select another message, but the
Page Up/Down keys are handled by the preview instead,
regardless of whether it has focus or not. Only if
the preview pane is hidden does the message list
respond to Page Up/Down keystrokes.
Hi David,
I've just discussed the thing rather extensively with an ex-senior scientist at Apple. I think that he is right - as you are -, this is intended behaviour.
Whether it is a good idea or not is a different matter however. Apple's keyboard commands have never been as complete, or precise, as Microsoft's. Remark that this is not a compliment to Microsoft whose interface is at times simply terrible! But here, it's not the keyboard command policy that is not systematic, it's the response of the mouse. And this I find very surprising. I have 51 mailboxes in Mail and the more control I have, the happier I am, that's for sure!
On the other hand, what surprised me is the fact that the mouse does not respond in the same way in, say, Mail and iTunes. In iTunes, if you click on a "folder" (they call them playlists, which is fine, but this is about the same as a folder is it not?), not only you select it, but you activate it: you give it the focus plain and simple.
Look at Font Book: here also, you have what a power user is waiting for: clicking on a "folder", or a list or group, you give it the focus plain and simple. Idem in Address Book. iPhoto also, but then it's the tab key behaviour that's strange.
I can see from here programming teams clashing over points like this one. I would greatly prefer that Apple's applications adopt a predictable behaviour from one app to the other.
"Behaviour by design", all right. I will nonetheless send to Apple what we could call an "enhancement request".
Cheers!
Roger the Photographer
G5 1.8Dual, 2GB RAM Mac OS X (10.4.8) 20" App Dsplay, ext. Lacie, iPod, Bach on Al-Lansing, Canon 5D, Canon L glass

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import java.awt.event.*;
import java.io.*;
import java.lang.*;
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thanks!
D Rice

I have used this and it leaves it with focus, modify the YourApp for the executable, I put it there so you would know where.....
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I am unable to give focus to newly opened window/frame
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jods

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so, would it look like
oldField.requestFocus;[ ? (oldField being the textfield)
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Hello,
I want to know how to give the focus to a JTextField.To be more precise,
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This thread may explain your problem:
http://forum.java.sun.com/thread.jsp?forum=57&thread=290339

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regards,
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[Flex 4.5.1] Focus on TextInput hides windows 7 language bar when in Chrome, Firefox works fine

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http://bugs.adobe.com/jira/browse/SDK-32039

Robot not working after another app gains focus

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billyboy:
How are you checking to see if it works? If you have an application that is processing the click events, and another application covers it, then it will no longer see the click events.
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import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
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import java.awt.Point;
import java.awt.Robot;
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int iCount = 0;
public JRobot(){
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HOW TO: SDI + Default Focus + CardLayout + jdk1.4

Hi,
I need some help to solve some focus issues.
I use jdk 1.4.1_01 and Win2000
I have a SDI application composed with:
< = include
JFrame < JScrollPane < JPanel (CardLayout) < JPanel 1 < JTextField11 *
| | < JTextField12
| | < JTextField13
| < JPanel 2 < JTextField21 *
| | < JTextField22
| | < JTextField23
| | < JTextField24
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| < JTextField32
| < JTextField33
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| < JTextField35
< JToolBar < JButton 1
< JButton 2
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JButton 1 -> JPanel 1 is displayed
JButton 2 -> JPanel 2 is displayed
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JButton 1 -> JPanel 1 is displayed AND JTextField11 get the focus
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JButton 3 -> JPanel 3 is displayed AND JTextField31 get the focus
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JMi

ok, done with requestFocus()

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