title: Make ViewPager swipable through external layout / from outside
body: <p>In my application I have an activity thats layout  is basicly following:</p>
  
  <p><a href="https://i.stack.imgur.com/nVVcg.png" rel="nofollow noreferrer">App layout</a></p>
  
  <p>The red part is a viewpager with fragments.
  The blue part is a layout with buttons that doesnt change with swipe on viewpager.
  But i want that the viewpager is swipable (smoothly) in the hole green framed area. It should act like normal viewpager behavior.</p>
  
  <p>I have absolutely no idea if that is even possible or not, but hope it does.</p>
  
  <p>I thought that it is maybe possible with a gestureoverlay or something, but don't know how to apply the detected gesture on the viewpager.
  Only detecting swipe and set current page is not what I want achieve.</p>
  
  <p>(I'm writing in java)</p>