FULL PRODUCT VERSION :
java version 1.5.0-b64

ADDITIONAL OS VERSION INFORMATION :
Microsoft Windows XP [Version 5.1.2600]

EXTRA RELEVANT SYSTEM CONFIGURATION :
Using JBuilder 2005 for a development platform

A DESCRIPTION OF THE PROBLEM :
I am using the PopupMenuDemo from the Swing tutorial with a slight modification to print whether the popup is showing or not.

If you look at the PopupMenuListener class, mousePressed and mouseReleased methods you will notice a checkPopup(e) method call where I check the value of popup.isShowing(). When the application is run in jdk1.4.2 this is the output of two successive single right button mouse clicks (in the content pane of the frame) is different from when running under JRE 1.5.0.

In other words, in jdk 5.0 the JPopupMenu.isShowing() method always returns false. We have an application (quite complex) that counts on this method in order to toggle a JPopupMenu and after we ported to 1.5 we couldn't close the JPopupMenu once it was open.

STEPS TO FOLLOW TO REPRODUCE THE PROBLEM :
1. Run the following code in jdk 5.0
2. When the frame shows up, press the right mouse button in the content pane (white area). Look at the printout.
3. Release the right mouse button. Look at the printout.
4. Press the right mouse button in another place within the content pane. Look at the printout.
5. Release the right mouse button. Look at the printout.

If you notice, the isShowing() method called on popup in checkPopup(MouseEvent e) in PopupListener always returns false.


EXPECTED VERSUS ACTUAL BEHAVIOR :
EXPECTED -
I expected on the second mouse press the popup to be showing. Please look at the second MOUSE_PRESSED event:

(Output of two successive right button mouse clicks)

MOUSE_PRESSED,(225,84),button=3,modifiers=Meta+Button3,extModifiers=Button3,clickCount=1
Popup is not showing
MOUSE_RELEASED,(220,68),button=3,modifiers=Meta+Button3,extModifiers=Meta,clickCount=1
Popup is not showing
MOUSE_PRESSED,(112,63),button=3,modifiers=Meta+Button3,extModifiers=Button3,clickCount=1
Popup is showing
MOUSE_RELEASED,(112,63),button=3,modifiers=Meta+Button3,extModifiers=Meta,clickCount=1

Popup is not showing
ACTUAL -
What happened is that the popup was not ever considered to be showing:

MOUSE_PRESSED,(225,84),button=3,modifiers=Meta+Button3,extModifiers=Button3,clickCount=1
Popup is not showing
MOUSE_RELEASED,(225,84),button=3,modifiers=Meta+Button3,extModifiers=Meta,clickCount=1
Popup is not showing
MOUSE_PRESSED,(120,47),button=3,modifiers=Meta+Button3,extModifiers=Button3,clickCount=1
Popup is not showing
MOUSE_RELEASED,(120,47),button=3,modifiers=Meta+Button3,extModifiers=Meta,clickCount=1
Popup is not showing

REPRODUCIBILITY :
This bug can be reproduced always.

---------- BEGIN SOURCE ----------
Please run the code in jdk 1.4.2 and 5.0 to notice the differences in popup.isShowing() (in checkPopup(MouseEvent e) in PopupListener)

import java.awt.*;
import java.awt.event.*;
import javax.swing.JPopupMenu;
import javax.swing.JMenu;
import javax.swing.JMenuItem;
import javax.swing.JCheckBoxMenuItem;
import javax.swing.JRadioButtonMenuItem;
import javax.swing.ButtonGroup;
import javax.swing.JMenuBar;
import javax.swing.KeyStroke;
import javax.swing.ImageIcon;

import javax.swing.JPanel;
import javax.swing.JTextArea;
import javax.swing.JScrollPane;
import javax.swing.JFrame;

/* PopupMenuDemo.java is a 1.4 application that requires images/middle.gif. */

/*
 * Like MenuDemo, but with popup menus added.
 */
public class PopupMenuDemo implements ActionListener, ItemListener {
    JTextArea output;
    JScrollPane scrollPane;
    String newline = "\n";

    public JMenuBar createMenuBar() {
        JMenuBar menuBar;
        JMenu menu, submenu;
        JMenuItem menuItem;
        JRadioButtonMenuItem rbMenuItem;
        JCheckBoxMenuItem cbMenuItem;

        //Create the menu bar.
        menuBar = new JMenuBar();

        //Build the first menu.
        menu = new JMenu("A Menu");
        menu.setMnemonic(KeyEvent.VK_A);
        menu.getAccessibleContext().setAccessibleDescription(
                "The only menu in this program that has menu items");
        menuBar.add(menu);

        //a group of JMenuItems
        menuItem = new JMenuItem("A text-only menu item",
                                 KeyEvent.VK_T);
        //menuItem.setMnemonic(KeyEvent.VK_T); //used constructor instead
        menuItem.setAccelerator(KeyStroke.getKeyStroke(
                KeyEvent.VK_1, ActionEvent.ALT_MASK));
        menuItem.getAccessibleContext().setAccessibleDescription(
                "This doesn't really do anything");
        menuItem.addActionListener(this);
        menu.add(menuItem);

        ImageIcon icon = createImageIcon("images/middle.gif");
        menuItem = new JMenuItem("Both text and icon", icon);
        menuItem.setMnemonic(KeyEvent.VK_B);
        menuItem.addActionListener(this);
        menu.add(menuItem);

        menuItem = new JMenuItem(icon);
        menuItem.setMnemonic(KeyEvent.VK_D);
        menuItem.addActionListener(this);
        menu.add(menuItem);

        //a group of radio button menu items
        menu.addSeparator();
        ButtonGroup group = new ButtonGroup();

        rbMenuItem = new JRadioButtonMenuItem("A radio button menu item");
        rbMenuItem.setSelected(true);
        rbMenuItem.setMnemonic(KeyEvent.VK_R);
        group.add(rbMenuItem);
        rbMenuItem.addActionListener(this);
        menu.add(rbMenuItem);

        rbMenuItem = new JRadioButtonMenuItem("Another one");
        rbMenuItem.setMnemonic(KeyEvent.VK_O);
        group.add(rbMenuItem);
        rbMenuItem.addActionListener(this);
        menu.add(rbMenuItem);

        //a group of check box menu items
        menu.addSeparator();
        cbMenuItem = new JCheckBoxMenuItem("A check box menu item");
        cbMenuItem.setMnemonic(KeyEvent.VK_C);
        cbMenuItem.addItemListener(this);
        menu.add(cbMenuItem);

        cbMenuItem = new JCheckBoxMenuItem("Another one");
        cbMenuItem.setMnemonic(KeyEvent.VK_H);
        cbMenuItem.addItemListener(this);
        menu.add(cbMenuItem);

        //a submenu
        menu.addSeparator();
        submenu = new JMenu("A submenu");
        submenu.setMnemonic(KeyEvent.VK_S);

        menuItem = new JMenuItem("An item in the submenu");
        menuItem.setAccelerator(KeyStroke.getKeyStroke(
                KeyEvent.VK_2, ActionEvent.ALT_MASK));
        menuItem.addActionListener(this);
        submenu.add(menuItem);

        menuItem = new JMenuItem("Another item");
        menuItem.addActionListener(this);
        submenu.add(menuItem);
        menu.add(submenu);

        //Build second menu in the menu bar.
        menu = new JMenu("Another Menu");
        menu.setMnemonic(KeyEvent.VK_N);
        menu.getAccessibleContext().setAccessibleDescription(
                "This menu does nothing");
        menuBar.add(menu);

        return menuBar;
    }

    public Container createContentPane() {
        //Create the content-pane-to-be.
        JPanel contentPane = new JPanel(new BorderLayout());
        contentPane.setOpaque(true);

        //Create a scrolled text area.
        output = new JTextArea(5, 30);
        output.setEditable(false);
        scrollPane = new JScrollPane(output);

        //Add the text area to the content pane.
        contentPane.add(scrollPane, BorderLayout.CENTER);

        return contentPane;
    }

    public void createPopupMenu() {
        JMenuItem menuItem;

        //Create the popup menu.
        JPopupMenu popup = new JPopupMenu();
        menuItem = new JMenuItem("A popup menu item");
        menuItem.addActionListener(this);
        popup.add(menuItem);
        menuItem = new JMenuItem("Another popup menu item");
        menuItem.addActionListener(this);
        popup.add(menuItem);

        //Add listener to the text area so the popup menu can come up.
        MouseListener popupListener = new PopupListener(popup);
        output.addMouseListener(popupListener);
    }

    public void actionPerformed(ActionEvent e) {
        JMenuItem source = (JMenuItem)(e.getSource());
        String s = "Action event detected."
                   + newline
                   + " Event source: " + source.getText()
                   + " (an instance of " + getClassName(source) + ")";
        output.append(s + newline);
        output.setCaretPosition(output.getDocument().getLength());
    }

    public void itemStateChanged(ItemEvent e) {
        JMenuItem source = (JMenuItem)(e.getSource());
        String s = "Item event detected."
                   + newline
                   + " Event source: " + source.getText()
                   + " (an instance of " + getClassName(source) + ")"
                   + newline
                   + " New state: "
                   + ((e.getStateChange() == ItemEvent.SELECTED) ?
                     "selected":"unselected");
        output.append(s + newline);
        output.setCaretPosition(output.getDocument().getLength());
    }

    // Returns just the class name -- no package info.
    protected String getClassName(Object o) {
        String classString = o.getClass().getName();
        int dotIndex = classString.lastIndexOf(".");
        return classString.substring(dotIndex+1);
    }

    /** Returns an ImageIcon, or null if the path was invalid. */
    protected static ImageIcon createImageIcon(String path) {
        java.net.URL imgURL = PopupMenuDemo.class.getResource(path);
        if (imgURL != null) {
            return new ImageIcon(imgURL);
        } else {
            System.err.println("Couldn't find file: " + path);
            return null;
        }
    }

    /**
     * Create the GUI and show it. For thread safety,
     * this method should be invoked from the
     * event-dispatching thread.
     */
    private static void createAndShowGUI() {
        //Make sure we have nice window decorations.
        JFrame.setDefaultLookAndFeelDecorated(true);

        //Create and set up the window.
        JFrame frame = new JFrame("PopupMenuDemo");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);

        //Create/set menu bar and content pane.
        PopupMenuDemo demo = new PopupMenuDemo();
        frame.setJMenuBar(demo.createMenuBar());
        frame.setContentPane(demo.createContentPane());

        //Create and set up the popup menu.
        demo.createPopupMenu();

        //Display the window.
        frame.setSize(450, 260);
        frame.setVisible(true);
    }

    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();
            }
        });
    }

    class PopupListener extends MouseAdapter {
        JPopupMenu popup;

        PopupListener(JPopupMenu popupMenu) {
            popup = popupMenu;
        }

        public void mousePressed(MouseEvent e) {
            checkPopup(e);
            maybeShowPopup(e);
        }

        public void mouseReleased(MouseEvent e) {
            checkPopup(e);
            maybeShowPopup(e);
        }

        private void maybeShowPopup(MouseEvent e) {
            if (e.isPopupTrigger()) {
// checkPopup();
                popup.show(e.getComponent(),
                           e.getX(), e.getY());
            }
        }

        private void checkPopup(MouseEvent e) {
            System.out.println(e.paramString());
            if (popup.isShowing()) {
                System.out.println("Popup is showing");
            } else {
                System.out.println("Popup is not showing");
            }
        }
    }
}
---------- END SOURCE ----------

CUSTOMER SUBMITTED WORKAROUND :
I am internally keeping track of the state of the popup with a boolean that I set and reset everytime it shows or hides.

Release Regression From : 1.4.2_06
The above release value was the last known release where this
bug was known to work. Since then there has been a regression.
###@###.### 2005-1-12 17:50:30 GMT