title: Android Floating activity with dismiss on swipe
body: <p>The latest Facebook's android app has a very nice floating comment window. There the user can dismiss the window swiping up or down making it really ease to use. </p>
  
  <p>I want to implement a similar behaviour in my app but I don't know how to do it. Any idea or clue about how to do it will be really appreciated.</p>
  
  <p>Screenshots of the Facebook app<br>
  (sorry, the Facebook app from where I took the screenshots is in Japanese)
  <img src="https://i.stack.imgur.com/AIY1d.png" alt="Swipe up">
  <img src="https://i.stack.imgur.com/ET3ke.png" alt="Swipe down"></p>