title: Fade out custom view while scrolling
body: <p>There is a custom fixed searchview, under the toolbar:</p>
  
  <pre><code>&lt;FrameLayout xmlns:android="http://schemas.android.com/apk/res/android"
           android:layout_width="match_parent"
           android:layout_height="match_parent"&gt;
  
  &lt;com.mobium.reference.views.AdvancedSearchView
      android:layout_width="match_parent"
      android:layout_height="wrap_content"/&gt;
  
  &lt;android.support.v7.widget.RecyclerView
      android:id="@+id/catalogItems"
      android:layout_width="match_parent"
      android:layout_height="wrap_content"
      android:layout_marginBottom="2dp"
      android:layout_marginTop="?attr/actionBarSize"
      android:scrollbars="vertical"/&gt;
  </code></pre>
  
  <p>I want to make fade out animation for it while scrolling recycler view down (Google I/O makes it with toolbar).</p>
  
  <p><a href="https://i.stack.imgur.com/dIRs5.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/dIRs5.png" alt="enter image description here"></a></p>
  
  <p>May be there is any way to do it with design support library, not sure how. </p>
  
  <p>I'll be glad for any tip, thanks !</p>