title: Create scroll layout like Instagram
body: <p>I want to design a app which have a new feed screen like Instagram app.</p>
  
  <p>If you have used Instagram you can see when you scroll up the toolbar will push up and replaced by header of feed. (Ok, I can do it which android support design) .</p>
  
  <p>When you continue scroll, the header of the second feed will push up and replace the header of the first. I wonder how can they do that ? How can they detect when an item is over ?</p>
  
  <p>This video demo how instagram app scroll :</p>
  
  <p><a href="https://www.youtube.com/watch?v=ThzZlrKVY-g" rel="nofollow">https://www.youtube.com/watch?v=ThzZlrKVY-g</a></p>
  
  <p>Sorry about my grammar, Thank in advanced !!!</p>