Register the `func` as a callback reacting only to ENTER.

    Note:
        This function doesn't bind the key to the element, just creates sort of
        filter, which ignores all other events.

def func_on_enter(func):
    """
    Register the `func` as a callback reacting only to ENTER.

    Note:
        This function doesn't bind the key to the element, just creates sort of
        filter, which ignores all other events.
    """
    def function_after_enter_pressed(ev):
        ev.stopPropagation()

        # if the key was `enter` ..
        if ev.keyCode == 13:
            func(ev)

    return function_after_enter_pressed