JPanel loses keyboard focus

Question

Ok, i have a JTextField which is initially disabled. A JPanel draws some stuff and receives keyboard input. When i enable the textfield, type some stuff, then press Esc (which disables it), i cant get the keyboard focus back on the JPanel. Here is an example:
(you can move the red circle before you enable the textfield, after you disable it, you cant move it anymore).
import java.awt.*;
import java.awt.event.*;
import javax.swing.*;
import javax.swing.border.*;
import javax.swing.event.*;
import java.util.Vector;
public class example extends JPanel implements ActionListener,Runnable {
    JFrame frame;
    JMenuBar menubar;
    JMenu m_file;
    JMenuItem mi_open,mi_close;
    JPanel canvas,northpanel;
    JTextField textfield;
    Image canvasimg;
    Thread thread=new Thread(this);
    private Image dbImage;     // for flickering
     private Graphics dbg;     // for flickering
     int x1=400,y1=200;
    public example() {
        frame = new JFrame("Example");                         // window
        frame.setLayout(null);
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.setPreferredSize(new Dimension(1000,700));
        frame.setLayout(new BorderLayout());
        northpanel=new JPanel();
        northpanel.setLayout(null);
        northpanel.setPreferredSize(new Dimension(1000,20));     northpanel.setLocation(0,0);
        menubar=new JMenuBar();
        m_file=new JMenu("File");   
        mi_open=new JMenuItem("Open");
        mi_close=new JMenuItem("Close");
        m_file.add(mi_open);
        m_file.add(mi_close);   
        m_file.getPopupMenu().setLightWeightPopupEnabled(false);   
        menubar.add(m_file);
        northpanel.add(menubar);
        menubar.setLocation(0,0);     menubar.setSize(80,20);
        textfield=new JTextField();
        northpanel.add(textfield);
        textfield.setSize(200,20);     textfield.setLocation(500,0);   
        textfield.setEnabled(false);
        frame.add(northpanel,BorderLayout.NORTH);
        canvas=new JPanel();
        canvas.setLayout(null);
        canvas.setSize(1000,600);
        canvas.setBackground(Color.white);
         frame.add(canvas,BorderLayout.CENTER);      
        frame.pack();
        frame.setVisible(true);       
        thread.start();                                   // start the thread
        textfield.addMouseListener(new MouseAdapter(){
                public void mousePressed(MouseEvent e){
                     textfield.setEnabled(true);
           textfield.addKeyListener(new KeyAdapter() {
             public void keyPressed(KeyEvent e){
                  int key=e.getKeyCode();
                  if(key==27){     // esc
                       textfield.setEnabled(false); 
                       canvas.setEnabled(true);                // not working
                       canvas.requestFocus();
                       canvas.requestFocusInWindow();
           frame.addKeyListener(new KeyAdapter() {
             public void keyPressed(KeyEvent e){                   
                  int key=e.getKeyCode();
                  if(key==37){ //left
                       x1-=5;
                  if(key==38){ //up
                       y1-=5;
                  if(key==39){ //right
                       x1+=5;
                  if(key==40){ //down
                       y1+=5;
    // Create the GUI and show it. 
    private static void createAndShowGUI() {
        JFrame.setDefaultLookAndFeelDecorated(true);
        example ex = new example();
    public void run(){
         while(true){
              try{
                   if(canvasimg==null)repaint();                   
                   Graphics g=canvas.getGraphics();
                   update(g);
                   thread.sleep(30);                                             // 1 sec
              }      catch(InterruptedException ex){}
    // ActionPerformed handles button and menu events
    public void actionPerformed(ActionEvent e){              
    public static void main(String[] args) {
        //Schedule a job for the event-dispatching thread:
        //creating and showing this application's GUI.
        javax.swing.SwingUtilities.invokeLater(new Runnable() {
            public void run() {
                createAndShowGUI();
    public void update (Graphics g){          // get rid of flicker
          if (dbImage == null){
               dbImage = canvas.createImage (canvas.getSize().width, canvas.getSize().height);
               dbg = dbImage.getGraphics ();
          dbg.setColor (canvas.getBackground ());
          dbg.fillRect (0, 0, this.getSize().width, this.getSize().height);
          dbg.setColor (canvas.getForeground());
          paint (dbg);
          g.drawImage (dbImage, 0, 0, this);
     public void paint(Graphics g){
          g.drawImage(canvasimg,0,0,this);          
          g.setColor(Color.red);
         g.fillOval(x1,y1,10,10);
    public void repaint(){     
         if(canvas!=null && canvasimg==null)canvasimg=canvas.createImage(1000,670);
         if(canvasimg==null)return;
         Graphics g=canvasimg.getGraphics();
         if(g==null)return;
         g.setColor(Color.white);
         g.fillRect(0,0,1000,600);
}  

Answer 1

OK great guru since you're so damn confident that you're doing everything right, find out for yourself why this works and yours doesn't.
I could list a few dozen things wrong with your code, but I'd be wasting my keystrokes.import java.awt.BorderLayout;
import java.awt.Color;
import java.awt.Dimension;
import java.awt.Graphics;
import java.awt.event.KeyAdapter;
import java.awt.event.KeyEvent;
import java.awt.event.MouseAdapter;
import java.awt.event.MouseEvent;
import javax.swing.JFrame;
import javax.swing.JMenu;
import javax.swing.JMenuBar;
import javax.swing.JMenuItem;
import javax.swing.JPanel;
import javax.swing.JTextField;
import javax.swing.SwingUtilities;
public class TextFieldDisableNoProblem extends JPanel {
   JPanel northPanel;
   JMenuBar menubar;
   JMenu m_file;
   JMenuItem mi_open,mi_close;
   JTextField textField;
   int x1 = 400;
   int y1 = 200;
   public TextFieldDisableNoProblem () {
      setBackground (Color.WHITE);
      addKeyListener (new KeyAdapter () {
         public void keyPressed (KeyEvent e){
            int key = e.getKeyCode ();
            switch (key) {
               case KeyEvent.VK_LEFT:
                     x1 -= 5;
                     break;
               case KeyEvent.VK_UP:
                     y1 -= 5;
                     break;
               case KeyEvent.VK_RIGHT:
                     x1 += 5;
                     break;
               case KeyEvent.VK_DOWN:
                     y1 += 5;
                     break;
            repaint ();
   void makeUI () {
      JFrame frame = new JFrame ("");
      frame.setDefaultCloseOperation (JFrame.EXIT_ON_CLOSE);
      frame.setSize (600, 500);
      frame.setLocationRelativeTo (null);
      menubar=new JMenuBar ();
      m_file=new JMenu ("File");
      mi_open=new JMenuItem ("Open");
      mi_close=new JMenuItem ("Close");
      m_file.add (mi_open);
      m_file.add (mi_close);
      menubar.add (m_file);
      frame.setJMenuBar (menubar);
      textField=new JTextField ();
      textField.setEnabled (false);
      textField.setBounds (200, 0, 200, 20);
      textField.addMouseListener (new MouseAdapter (){
         public void mousePressed (MouseEvent e){
            textField.setEnabled (true);
      textField.addKeyListener (new KeyAdapter () {
         public void keyPressed (KeyEvent e){
            int key = e.getKeyCode ();
            if(key == KeyEvent.VK_ESCAPE){
               textField.setEnabled (false);
               requestFocus ();
      northPanel=new JPanel ();
      northPanel.setLayout (null);
      northPanel.setPreferredSize (new Dimension (600,20));
      northPanel.add (textField);
      frame.add (northPanel,BorderLayout.NORTH);
      frame.add (this, BorderLayout.CENTER);
      frame.setVisible (true);
      requestFocus ();
   public void paintComponent (Graphics g) {
      super.paintComponent (g);
      g.setColor (Color.RED);
      g.fillOval (x1, y1, 10, 10);
   public static void main (String[] args) {
      SwingUtilities.invokeLater (new Runnable () {
         public void run () {
            JFrame.setDefaultLookAndFeelDecorated (true);
            new TextFieldDisableNoProblem ().makeUI ();
}db