I have a main application window, I want to invoke a 2nd window
and hide the first main window. What happened was it reported the
error message as follows:

Received a mouse event from a non-showing Component com.sun.java.swing.JMenu[,0,
1,39x19,layout=com.sun.java.swing.OverlayLayout, JMenu]

I don't think this message should be printed.
Please advise me ASAP if there is a work-around. Thanks!

I have stripped down my code to two simple files: MainFrame.java & ResultWindow.java
You may compile them to see the error.


// MainFrame.java --------------------------------------------------------------------------
import java.awt.*;
import java.util.*;
import java.awt.event.*;
import com.sun.java.swing.*;

/**
 * The application main entry class
 */
public class MainFrame extends JFrame
{
    static ResultWindow jResultWindow; // the result window for displaying data
    static MainFrame jMainAppFrame; // application's main frame

 JMenuBar mainMenuBar;
 JMenu menuFile;
 JMenuItem miOpen;
 JMenuItem miViewResult;
 JMenuItem miExit;

    /** Constructor **/
 public MainFrame()
 {

  mainMenuBar = new JMenuBar();
  menuFile = MainFrame.addMenu(mainMenuBar, "File", 'F');
                miViewResult = MainFrame.addMenuItem(menuFile, "View Result Window", 'R');
  menuFile.addSeparator();
  miExit = MainFrame.addMenuItem(menuFile, "Exit", 'X');

  setJMenuBar(mainMenuBar);

        SymAction lSymAction = new SymAction();
  miViewResult.addActionListener(lSymAction);
  miExit.addActionListener(lSymAction);
 }

 public MainFrame(String title)
 {
  this();
  setTitle(title);
 }

    /**
     * Call this method to center the window in the screen
     */
    static void centerWindow(java.awt.Window frame)
    {
        //Center the window
        Dimension screenSize = Toolkit.getDefaultToolkit().getScreenSize();
        Dimension frameSize = frame.getSize();
        if (frameSize.height > screenSize.height)
          frameSize.height = screenSize.height;
        if (frameSize.width > screenSize.width)
          frameSize.width = screenSize.width;
        frame.setLocation((screenSize.width - frameSize.width) / 2, (screenSize.height - frameSize.height) / 2);
    }

 public static void main(String args[])
 {
        // create the MainFrame
        jMainAppFrame = new MainFrame();

        // Center the Frame window and display it
     jMainAppFrame.setSize(450,320);
     MainFrame.centerWindow(jMainAppFrame);
        jMainAppFrame.setVisible(true);
 }

 /**
  * Creates and displays the Result Window and hides the Main Window.
  */
    public static synchronized ResultWindow createResultWindow(boolean bViewOnly)
    {
        // display wait cursor while canceling test
// Cursor oldCursor = getCursor();
// setCursor(new Cursor(WAIT_CURSOR));

        // create the result window
        jResultWindow = new ResultWindow(bViewOnly);

        jResultWindow.setLocation(jMainAppFrame.getLocation());
        jResultWindow.setVisible(true);
        jMainAppFrame.setVisible(false);

// setCursor(oldCursor);

  return jResultWindow;
    }

 class SymAction implements java.awt.event.ActionListener
 {
  public void actionPerformed(java.awt.event.ActionEvent event)
  {
   Object object = event.getSource();
   if (object == miViewResult) {
       createResultWindow(true);
   }
   else if (object == miExit)
    miExit_Action(event);
     }
 }

 void miExit_Action(java.awt.event.ActionEvent event)
 {
     setVisible(false); // hide the Frame
  dispose(); // free the system resources
  System.exit(0); // close the application
 }

 public static JMenu addMenu(JMenuBar parent, String menuname, char mnemonic)
 {
  JMenu menu = new JMenu(menuname);
  menu.setMnemonic(mnemonic);
  parent.add(menu);
  return menu;
 }

 public static JMenuItem addMenuItem(JMenu parent, String menuname, char mnemonic)
 {
  JMenuItem menu = new JMenuItem(menuname);
  menu.setMnemonic(mnemonic);
  parent.add(menu);
  return menu;
 }
}



// ResultWindow.java ------------------------------------------------------------------------------------

import java.awt.*;
import java.io.*;
import java.util.*;
import java.awt.event.*;
import com.sun.java.swing.*;
import com.sun.java.swing.plaf.basic.*;

public class ResultWindow extends JFrame
{
    final String APP_RESULT_WIN_STR = "Result Window";
 boolean jIsViewOnly;
 JMenuBar mainMenuBar;
 JMenu menuFile;
 JMenuItem miClose;

    ResultWindow(boolean bViewOnly)
    {
  jIsViewOnly = bViewOnly;

        // set JFrame's layout manager
        getContentPane().setLayout(new BorderLayout());

  mainMenuBar = new JMenuBar();
  menuFile = MainFrame.addMenu(mainMenuBar, "File", 'F');
  miClose = MainFrame.addMenuItem(menuFile, "Close", 'C');
  setJMenuBar(mainMenuBar);

        setTitle(APP_RESULT_WIN_STR);
        setSize(550,350);
        setLocation(300,200);

  SymAction lSymAction = new SymAction();
  miClose.addActionListener(lSymAction);
    }

 class SymAction implements java.awt.event.ActionListener
 {
  public void actionPerformed(java.awt.event.ActionEvent event)
  {
   Object object = event.getSource();
   if (object == miClose)
    miClose_Action(event);
     }
 }

    void miClose_Action(java.awt.event.ActionEvent event)
 {
        closeWindow();
 }

    void closeWindow() {
        setVisible(false);
     dispose(); // free the system resources
        MainFrame.jMainAppFrame.setVisible(true);
    }
}