title: How to get an offset in RecyclerView ItemDecorator
body: <p>I have written two <code>ItemDecorator</code>'s for <code>RecyclerView</code>. Each adds some top offset in <code>getItemOffsets()</code>. Let's say:</p>
  
  <ul>
  <li>First decorator adds 20dp top offset</li>
  <li>Second decrator adds 30dp top offset</li>
  </ul>
  
  <p>Now, when I add both of them to <code>RecyclerView</code>, each item is correctly offsetted by 50dp, that's good.</p>
  
  <p>But here comes the question: 
  How do I get this offset in <code>onDraw</code>/<code>onDrawOver</code>?</p>
  
  <p>Usually decorators draw their stuff by traversing <code>parent.getChildAt(i)</code> stuff and getting <code>child.getTop()</code> for example to draw above child view of <code>RecyclerView</code>.</p>
  
  <p>But in this case, doing so would mix up the drawing of other decorator, because it would also use <code>child.getTop()</code>.</p>
  
  <p>So at the moment it seems like both decorators need to know about each other and each other's height.</p>
  
  <p>Am I missing something here? I hope I am.</p>
  
  <p><strong>EDIT:</strong> <em>I reported an issue to Android issue tracker and it seems this will be worked on. Star it to keep track of progress:</em> <a href="https://code.google.com/p/android/issues/detail?id=195746" rel="nofollow">https://code.google.com/p/android/issues/detail?id=195746</a></p>