title: How to get UIScrollView vertical direction in Swift?
body: <p>How can I get the scroll/swipe direction for up/down in a VC?</p>
  
  <p>I want to add a UIScrollView or something else in my VC that can see if the user swipes/scrolls up or down and then hide/show a <code>UIView</code> depending if it was an up/down gesture.</p>