Java detect CTRL+X key combination on a jtree

Question

I need an example how to add a keyboard handler that detect when Ctrl+C , Ctrl+X , Ctrl+C pressed on a JTree.

I were do this before with menu shortcut keys but with no success.

Cuirass

Although these suggestions will work, they really deserve a -1. Swing was designed to be used with Key Bindings, not KeyListeners. See: download.oracle.com/javase/tutorial/uiswing/misc/…. Solutions should promote standard Swing design concepts. Using KeyListeners is used on older AWT applications which don't support key bindings. – Leela

See camickr's answer for the working link to the Key Bindings tutorial. – Molli

Answer 1

You can add KeyListeners to any component (f)

        f.addKeyListener(new KeyListener() {

            @Override
            public void keyTyped(KeyEvent e) {
            }

            @Override
            public void keyPressed(KeyEvent e) {
                if ((e.getKeyCode() == KeyEvent.VK_C) && ((e.getModifiers() & KeyEvent.CTRL_MASK) != 0)) {
                    System.out.println("woot!");
                }
            }

            @Override
            public void keyReleased(KeyEvent e) {
            }
        });

Robins

Use Toolkit.getMenuShortcutKeyMask() instead of hard-coding CTRL_MASK. Not all platforms use Ctrl as the modifier for commands. – Issuable

Key Bindings are the approach used by all Swing components. – Leela

InputEvent.CTRL_MASK is deprecated-ish, the extended modifiers (e.g. InputEvent.CTRL_DOWN_MASK) are recommended for use now. Annoying but true. docs.oracle.com/javase/6/docs/api/java/awt/event/… – Mccormac

if ((e.getKeyCode() == KeyEvent.VK_C) && ((e.getModifiers() & KeyEvent.CTRL_MASK) != 0)) { System.out.println("woot!"); } } Would treat "Alt+CTRL+C" = "CTRL+C". The proposed sulution actually can't distinguish from any multiple modifiers. Use rather @Override public void keyPressed(KeyEvent e) { if ((e.getKeyCode() == KeyEvent.VK_C) && ((e.getModifiers() | KeyEvent.CTRL_MASK) == KeyEvent.CTRL_MASK)) { System.out.println("woot!"); } } – Spellbinder

For some reason, in my testing Ctl-A shows up with KeyCode 0 and KeyChar 1. Similarly, Ctl-N shows up with KeyChar 14. (The number of the letter in the alphabet.) Don't know if this is documented somewhere. – Molli

how about if i press CTRL + ALT + A ? – Petrarch

Answer 2

Use KeyListener for example :

jTree1.addKeyListener(new java.awt.event.KeyAdapter() {

        public void keyPressed(java.awt.event.KeyEvent evt) {
            if (evt.isControlDown() && evt.getKeyCode() == KeyEvent.VK_C) {

                JOptionPane.showMessageDialog(this, "ctrl + c");

            } else if (evt.isControlDown() && evt.getKeyCode() == KeyEvent.VK_X) {

                JOptionPane.showMessageDialog(this, "ctrl + x");

            } else if (evt.isControlDown() && evt.getKeyCode() == KeyEvent.VK_V) {

                JOptionPane.showMessageDialog(this, "ctrl + v");

            }
        }
    });

Hope that helps.

Tetracycline

Key Bindings are the approach used by all Swing cvomponents. – Leela

Answer 3

Use Key Bindings.

Leela

Answer 4

    initComponents();
      KeyboardFocusManager ky=KeyboardFocusManager.getCurrentKeyboardFocusManager();

    ky.addKeyEventDispatcher(new KeyEventDispatcher() {

        @Override
        public boolean dispatchKeyEvent(KeyEvent e) {

             if (e.getID()==KeyEvent.KEY_RELEASED && (e.getKeyCode() == KeyEvent.VK_C) && ((e.getModifiers() & KeyEvent.CTRL_MASK) != 0)) {
                System.out.println("Dhanushka Tharindu");
            }
             return  true;
        }
    });

Syllable

You should also provide an explanation of how the code works. – Mealworm

Answer 5

But menu shortcut accelerators are the way to do this normally: myMenuItem.setAccelerator(KeyStroke.getKeyStroke("control C"));

Australian

System reserved Key Combinations seems conflict Accelerator. i did it but its not work. any chance to add a keyboard handler to detect? – Cuirass

yes you can add a keylistener to the control, implement the onKeyPress() and check for the modifiers of the keyevent. I did it to detect a mousewhell + ctrl, but it should work as well in your case. – Australian