title: How to change FloatingActionButton between Tabs?
body: <p>I'm trying to implement  <strong><em>FloatingActionButton</em></strong>
  from  <strong><em>Google Design Support Library</em></strong> into two of three tabs, and according to the <a href="https://www.google.com/design/spec/components/buttons-floating-action-button.html#buttons-floating-action-button-floating-action-button">Material Design Guidelines - FloatingActionButton</a>
  it says: </p>
  
  <blockquote>
    <p>If there is a floating action button on multiple lateral screens (such
    as on tabs), upon entering each screen, the button should show and
    hide if the action contained on each is different. If the action is
    the same, the button should stay on screen (and translate to a new
    position, if necessary.)</p>
  </blockquote>
  
  <p><img src="https://i.stack.imgur.com/GGuG2.gif" alt="Example of FAB animation in tabs"></p>
  
  <p>How can I make this kind of transition or animation for the FAB buttons in my app?</p>