Karel KeyListener

KarelDriver.java

        //Add these lines to the top of your main method to make the key listener work
        //implement the variable listener however you want, this anonymous one is just a sample
        KeyListener listener = new KeyListener() {
            @Override
            public void keyPressed(KeyEvent e) {
                //using e.getChar() is not always a reliable way to find out what key is pressed
                //I think you're supposed to use e.getKeyCode which will return an int representing a VK_ (virtual key) value
                System.out.println("pressed " + e.getKeyChar());
            }
            
            @Override
            public void keyReleased(KeyEvent e) {
                System.out.println("released " + e.getKeyChar());
            }
            
            @Override
            public void keyTyped(KeyEvent e) {
                System.out.println("typed " + e.getKeyChar());
            }
        };
        
        //this class tells the JVM to also send key events to the listener above.
        //it's ugly, but the only way to hide it is add it to a library. It is static though.
        KeyboardFocusManager.getCurrentKeyboardFocusManager()
                .addKeyEventDispatcher(new KeyEventDispatcher() {
            @Override
            public boolean dispatchKeyEvent(KeyEvent e) {
                switch (e.getID()) {
                    case KeyEvent.KEY_PRESSED:
                        listener.keyPressed(e);
                        break;
                    case KeyEvent.KEY_RELEASED:
                        listener.keyReleased(e);
                        break;
                    case KeyEvent.KEY_TYPED:
                        listener.keyTyped(e);
                        break;
                }
                //must return false to ensure the other KeyEventDispatchers work as intended.
                return false;
            }
        });