ViewPager.SetOnTouchListener to differentiate between Tap and Swipe?

Question

How can I detect if the user did only tap and NOT swipe the ViewPager?

When I use OnTouchListener, I can never "just" touch or swipe. A Move event is always preceded by an Up / Down event.

This code always shows me the Toast, no matter if I just tap or swipe:

public class CardPicker : Fragment, View.IOnTouchListener
{
        public override View OnCreateView(LayoutInflater inflater, ViewGroup container, Bundle savedInstanceState)
        {
            var view = inflater.Inflate(Resource.Layout.Cardpicker, container, false);

            _cardPicker = view.FindViewById<ViewPager>
            _cardPicker.SetOnTouchListener(this);

            return view;
        }

        public bool OnTouch(View v, MotionEvent e)
        {
            if (e.Action == MotionEventActions.Down)
            {
                Toast.MakeText(Context,"Starting an Activity!", ToastLength.Short).Show();
                return true;
            }
            return false;
        }
}