public boolean addJoystickConnectionListener(JoystickConnectionListener listener) {
        return joystickConnectionListeners.add(listener);
    }
Add a listener that reports when a joystick has been added or removed.
Currently implemented only in LWJGL3.

@param listener the listener
@return true
jme3-core/src/main/java/com/jme3/input/InputManager.java