Adding TAB key java swing keybindings — What is the correct name?

Question

Action tab = new AbstractAction() {
        public void actionPerformed(ActionEvent e) {    
            System.err.println("@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@@");
        }
    };

Game.panel.getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke("Tab"), "tab");
Game.panel.getActionMap().put("tab", tab);

However its not printing. This is the same set up that I use for all my other keys, but I can't get the tab key to work. I've tried "TAB" , "Tab" , and "tab" .

What's the correct name for it? Or is there something special?

Answer 1

You probably want:

KeyStroke.getKeyStroke('\t');

\\t is the escape sequence for the TAB character (0x09) , which is output by pressing tab on your keyboard .

There is also KeyEvent.VK_TAB which might be preferable depending on your use case. See the documentation in KeyEvent for more on why you should prefer one or the other.

Answer 2

I'm surprised that KeyStroke works for you since the Tab character is generally handled by the focus subsystem.

It doesn't work for me. I'm using JDK8 on Windows 7:

import java.awt.*;
import java.awt.event.*;
import javax.swing.*;

public class TabSSCCE extends JPanel
{
    public TabSSCCE()
    {
        Action tab = new AbstractAction()
        {
            public void actionPerformed(ActionEvent e)
            {
                System.out.println("key typed");
            }
        };

        getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke('1'), "typed");
        getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke('a'), "typed");
        getInputMap(JComponent.WHEN_IN_FOCUSED_WINDOW).put(KeyStroke.getKeyStroke('\t'), "typed");
        getActionMap().put("typed", tab);
    }

    private static void createAndShowGUI()
    {
        JFrame frame = new JFrame("TabSSCCE");
        frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
        frame.add(new TabSSCCE());
        frame.setLocationByPlatform( true );
        frame.setSize(100, 100);
        frame.setVisible( true );
    }

    public static void main(String[] args)
    {
        EventQueue.invokeLater( () -> createAndShowGUI() );
/*
        EventQueue.invokeLater(new Runnable()
        {
            public void run()
            {
                createAndShowGUI();
            }
        });
*/
    }
}

Does the above code work for you?

Only the "1" and "a" work for me. The Tab key does not work for me.

If not, then can you post a simple SSCCE showing how you are using this?

Edit:

The above code will work with either of the following:

frame.setVisible( true );
frame.setFocusTraversalKeysEnabled(false);

or you can disable the focus traversal keys for the panel:

public TabSSCCE()
{
    setFocusable(true);
    setFocusTraversalKeysEnabled(false);

    ...
}