Java Swing L&F native keyboard shortcuts

Question

How do I leverage standard operating system keyboard shortcuts in a Java Swing application? I see how to add a javax.swing.JToolbar or a menu bar to my application, but it doesn't appear to be bound to de facto standard keyboard shortcuts (like Ctrl+S for Save).

Answer 1

You can use Toolkit.getDefaultToolkit.getMenuShortcutKeyMask() to get the correct modifier key per-platform (Ctrl, Command, etc.), but I'm not aware of any way to find out what the "standard" shortcuts for an action are, without defining them yourself.

Something that excels a little bit more at being native, like SWT, might be better at this kind of thing, though.

Answer 2

Building off of other people's answers, I thought I'd share what I did in my own app...

First, I have a class variable which is declared and initialized like this:

private static int keyMask = Toolkit.getDefaultToolkit().getMenuShortcutKeyMask();

Next, in the same class, I have this method:

private static void addNewMenuItem(JMenu rootMenu, String itemName,
        int itemMnemonic, ActionListener itemActionListener) {
    JMenuItem menuItem = new JMenuItem(itemName, itemMnemonic);
    menuItem.setAccelerator(KeyStroke.getKeyStroke(itemMnemonic, keyMask)); // <-- Where I use keyMask.
    menuItem.addActionListener(itemActionListener);
    rootMenu.add(menuItem);
}

Now, all that I have to do to create a new menu is write something like:

addNewMenuItem(fileMenu, "Save...", KeyEvent.VK_S, saveListener);

As you might imagine, it's a really handy method for cleaning up code where I'm setting up a menu with dozens of items! I hope that helps someone. (I didn't go the Action route because it would require me to set up a new class for each action... that seemed like an irritating limitation to have to get around. I'm pretty sure this code is shorter than that code would be.)

Answer 3

Read the Swing tutorial on How to Use Actions.

An Action is basically an ActionListener with a few more properties. You can define the text, mnemonic and accelerators for the Action. Then you can use the same Action to create a JButton which you add to a toolbar or a JMenuItem which you add to a menu.

Answer 4

You should manually bind your keyboard shortcut to the desired menu entry. For example using the setAccelerator() method on JMenuItem.