make enter key act like a tab key for jtextfield,jcombobox,jspinner in java

Question

I want enter key to behave like tab key in my swing application.And this class is working fine for JTextFields.How can i do the same for JComboBox and Jspinner or for the other controls on the frame?kindly help.

class MyTextField extends JTextField {
    MyTextField(int len) {
    super(len);
    addKeyListener(new KeyAdapter() {
            @Override
      public void keyPressed(KeyEvent evt) {
        int key = evt.getKeyCode();
        if (key == KeyEvent.VK_ENTER)
          transferFocus();
      }
    });
  }
}

Answer 1

Enter has special meaning for most components in Swing, for example JTextField will trigger actionPerformed on registered ActionListeners when Enter is pressed. Modifying this behaviour may have unexpected results for your application and may confuse many users...

Having said that, the best way to change the focus traversal keys is to provide a Set of KeyStrokes to the KeyboardFocusManager. This will (mostly) make the key's global.

Some component's supply there own focus traversal keys however, like JTextArea and JTable

Take a look at How to use Focus Subsystem for more details

import java.awt.BorderLayout;
import java.awt.EventQueue;
import java.awt.GridBagLayout;
import java.awt.KeyboardFocusManager;
import java.awt.event.ActionEvent;
import java.awt.event.ActionListener;
import java.awt.event.KeyEvent;
import java.util.HashSet;
import java.util.Set;
import javax.swing.JFrame;
import javax.swing.JPanel;
import javax.swing.JScrollPane;
import javax.swing.JTextArea;
import javax.swing.JTextField;
import javax.swing.KeyStroke;
import javax.swing.UIManager;
import javax.swing.UnsupportedLookAndFeelException;

public class TestFocusTraversal {

    public static void main(String[] args) {
        new TestFocusTraversal();
    }

    public TestFocusTraversal() {
        EventQueue.invokeLater(new Runnable() {
            @Override
            public void run() {
                try {
                    UIManager.setLookAndFeel(UIManager.getSystemLookAndFeelClassName());
                } catch (ClassNotFoundException | InstantiationException | IllegalAccessException | UnsupportedLookAndFeelException ex) {
                }

                JFrame frame = new JFrame("Testing");
                frame.setDefaultCloseOperation(JFrame.EXIT_ON_CLOSE);
                frame.setLayout(new BorderLayout());
                frame.add(new TestPane());
                frame.pack();
                frame.setLocationRelativeTo(null);
                frame.setVisible(true);
            }
        });
    }

    public class TestPane extends JPanel {

        public TestPane() {
            setLayout(new GridBagLayout());
            for (int index = 0; index < 10; index++) {
                JTextField tf = new JTextField(5);
                tf.addActionListener(new ActionListener() {
                    @Override
                    public void actionPerformed(ActionEvent e) {
                        System.out.println("...");
                    }
                });
                add(tf);
            }

            add(new JScrollPane(new JTextArea(10, 10)));

            KeyStroke enter = KeyStroke.getKeyStroke(KeyEvent.VK_ENTER, 0);
            KeyStroke tab = KeyStroke.getKeyStroke(KeyEvent.VK_TAB, 0);
            KeyStroke ctrlTab = KeyStroke.getKeyStroke(KeyEvent.VK_TAB, KeyEvent.CTRL_DOWN_MASK);
            Set<KeyStroke> keys = new HashSet<>();
            keys.add(enter);
            keys.add(tab);
            keys.add(ctrlTab);
            KeyboardFocusManager.getCurrentKeyboardFocusManager().setDefaultFocusTraversalKeys(KeyboardFocusManager.FORWARD_TRAVERSAL_KEYS, keys);
        }
    }

}