title: Material Design checklist: hiding app bar on scroll?
body: <p>Per the new Android Material Design checklist:</p>
  
  <p><a href="http://android-developers.blogspot.com/2014/10/material-design-on-android-checklist.html">http://android-developers.blogspot.com/2014/10/material-design-on-android-checklist.html</a></p>
  
  <blockquote>
    <p>Where appropriate, upon scrolling down, the app bar can scroll off the screen, leaving more vertical space for content. Upon scrolling back up, the app bar should be shown again.</p>
  </blockquote>
  
  <p>I realize there are lots of questions/answers to implement this behavior for the ICS-style app bar, but I'm curious if the new Toolbar widget or Lollipop/AppCompat 21 have introduced a more standard way of achieving this effect.</p>