keyboard vs menu conflict on Java 7, Mac OS - macos

Question

How can I get a Java 7 application to have its menu bar at the top of the screen (on a Mac) and also have correctly working keyboard shortcuts?
I have a Java application with a Swing user interface. Many menus have keyboard equivalents, which are essential.
There is very little that is system-dependent, but on Mac OS X the menu bar should appear at the top of the screen instead of on each window, so I set apple.laf.useScreenMenuBar.
This works fine on Java 6, but on Java 7 (out last week!) compiling and running the same code causes the keyboard shortcuts to carry out their menu actions twice. For example, in the attached code, Command ⌘ + O opens two file dialogues instead of one. (The other keyboard shortcuts also act twice, but you sometimes have to move windows to see that they did.)
The keyboard problem goes away if I don't set apple.laf.useScreenMenuBar, and that's what I'll do if I have to, but my Mac users will be displeased. I'd really like to have the menu bar in the right place and the keyboard shortcuts working.
System: Mac OS 10.7.3 (Lion) on a late-2010 MacBook Pro
Java 7:
java version "1.7.0_04"
Java(TM) SE Runtime Environment (build 1.7.0_04-b21)
Java HotSpot(TM) 64-Bit Server VM (build 23.0-b21, mixed mode)
Java 6:
java version "1.6.0_31"
Java(TM) SE Runtime Environment (build 1.6.0_31-b04-415-11M3635)
Java HotSpot(TM) 64-Bit Server VM (build 20.6-b01-415, mixed mode)
Where I've looked:
A discussion of why apple.laf.useScreenMenuBar should be gotten rid of
-- I'm all for it, but it doesn't seem to have happened.
A discussion about not using mrj.version to detect that you're on a Mac
-- not directly relevant, but sounded promising.
My apologies for the length of the attached code (148 lines), but my Swing coding is very old-fashioned. It should compile and run from the command line without any special flags or settings.
import javax.swing.*;
import java.awt.Toolkit;
import java.awt.*;
import java.awt.event.*;
/**
* Shows that using the single screen-top menu bar on a Mac with Java 7
* causes keyboard shortcuts to act twice.
*
* To see the problem(on a Mac -- running OS X 10.7.3 in my case):
* 1) compile on either Java 6 or Java 7
* 2) run on Java 7
* 3) give the command-O shortcut
* You will see two file dialogues.
*
* -- J. Clarke, May 2012
*/
public class MenuBug {
private static void go(String[] args) {
// Comment out the following line to fix the problem;
// leave it active to see the problem.
// It doesn't help to ...
// ... put the line into a static block.
// ... put the line right after the setLookAndFeel call.
// ... put the line before after the setLookAndFeel call.
System.setProperty("apple.laf.useScreenMenuBar", "true");
MainWindow mainWindow = new MainWindow();
}
public static void main(final String[] args) {
try {
UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
}
catch (Exception e) {
JOptionPane.showMessageDialog(null,
e + " while loading look and feel",
"MenuBug error", JOptionPane.ERROR_MESSAGE);
System.exit(1);
}
SwingUtilities.invokeLater(new Runnable() {
public void run() {
go(args);
}
});
}
}
class MainWindow extends JFrame {
MainWindow() {
super ("Main Window");
setDefaultCloseOperation(WindowConstants.DO_NOTHING_ON_CLOSE);
addWindowListener (new WindowAdapter() {
public void windowClosing(WindowEvent e) {
dispose();
System.exit(0);
}
});
JMenuBar menuBar = createMenuBar();
setJMenuBar(menuBar);
pack();
setSize(350,300);
setVisible(true);
}
private JMenuBar createMenuBar() {
JMenuBar mBar = new JMenuBar();
JMenu menu = new JMenu("File");
String[] menuItemNames = new String[] {"New", "Open...", "Other"};
for (int i = 0; i < menuItemNames.length; i++) {
String miName = menuItemNames[i];
JMenuItem mi = new JMenuItem(miName);
mi.setActionCommand(miName);
linkMenuItemToAction(mi);
menu.add(mi);
}
mBar.add(menu);
return mBar;
}
/**
* Create an Action for menuItem, and make sure the action and the menu
* item know about each other; where appropriate, add keyboard equivalents.
* #param menuItem The menu item to be linked to an action.
*/
private void linkMenuItemToAction(JMenuItem menuItem) {
final int META_MASK =
Toolkit.getDefaultToolkit().getMenuShortcutKeyMask();
Action a = null;
String miName = menuItem.getActionCommand();
if (miName.equals ("New")) {
a = new NewAction();
menuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_N,
META_MASK));
}
else if (miName.equals ("Open...")) {
a = new OpenAction();
menuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_O,
META_MASK));
}
else if (miName.equals ("Other")) {
a = new OtherAction();
menuItem.setAccelerator(KeyStroke.getKeyStroke(KeyEvent.VK_T,
META_MASK));
}
menuItem.setEnabled(a.isEnabled());
menuItem.addActionListener(a);
}
private class NewAction extends AbstractAction {
public void actionPerformed(ActionEvent e) {
new MainWindow();
}
}
private void makeDialog() {
String dialogTitle = "Please choose a file to open";
FileDialog fileDialog = new FileDialog(this, dialogTitle,
FileDialog.LOAD);
fileDialog.setVisible(true);
String fileName = fileDialog.getFile();
}
private class OpenAction extends AbstractAction {
public void actionPerformed(ActionEvent e) {
makeDialog();
}
}
private class OtherAction extends AbstractAction {
public void actionPerformed(ActionEvent e) {
JOptionPane.showMessageDialog(null,
"an example message",
"not really an error", JOptionPane.ERROR_MESSAGE);
}
}
}

Answer 1

I'm answering my own question -- sort of. As noted in the comments to the original, the trouble goes away with Java 1.7u10.

Answer 2

It looks like that this problem still exist but now it can be reproduced with fn + backSpace (delete) on mac with 1.7_21.
I used the same example as above just added text field. Select part of text in textfield and press delete (fn+backspace)
Change KeyStroke to "DELETE" in linkMenuItemToAction method
else if (miName.equals ("Other"))
{
a = new OtherAction();
menuItem.setAccelerator(KeyStroke.getKeyStroke("DELETE"));
}
and add this:
JTextField textField = new JTextField(10);
textField.setText("Long long long long long long long text");
add(textField, BorderLayout.PAGE_START);
to MainWindow constructor.