title: Android when OnLayout calls?
body: <p>I developing a custom <code>View</code> which extends from <code>ViewGroup</code>. It means that i need to implement <code>onLayout</code> method. I was think that this method calls when View displays on screen but i think that is not right. </p>
  
  <p>Can you explain me when <code>onLayout</code> method calls and what i need implementing in this method?</p>
  
  <p>It make me crash because i see an AdapterView in Android SDK onLayout implementation and that make me confuse because no one parameter in this method not used.</p>
  
  <pre><code>@Override
  protected void onLayout(boolean changed, int left, int top, int right, int bottom) {
      mLayoutHeight = getHeight();
  }
  </code></pre>