title: Android: show/hide a view using an animation
body: <p>I've been looking through many google results / questions on here to determine how to show/hide a view via a vertical animation, but I can't seem to find one that's exactly right or not too vague.</p>
  
  <p>I have a layout (undo bar) that's below another layout and above multiple other widgets; this undo bar should vertically slide open and slide closed, depending on the circumstances.</p>
  
  <p>Currently all I do right now is set the view to be visible or gone.</p>