title: Access to a ScrollView of a ViewController from another view
body: <p>I actually work on a app in <code>Swift</code>.
  I have my main <code>ViewController</code> with a <code>ScrollView</code> only.</p>
  
  <p>In my swift file i add 3 view (3 subview controller) into the <code>ScrollView</code> in order to have a special navigation (horizontal navigation like a <code>View Pager</code>).</p>
  
  <p><img src="https://i.stack.imgur.com/C83Mz.png" alt="The main ViewController with his subviews"></p>
  
  <p>The problem is that each view has his swift file and therefore i don't find the solution to communicate with the <code>ScrollView</code> of the main <code>ViewController</code> from a <code>subview</code>.</p>
  
  <p>For example a <code>SubViewController</code> (one of the three) have button on it.
  And i would put a listener on this button and On click move the position of the screen in the <code>ScrollView</code> (which is on the main <code>view controller</code>), thanks to the method <code>setContentOffset</code> of the <code>scrollview</code>.</p>