title: Flex 4 UIComponent width and height remains zero after addChild is called
body: <p>I have a component <code>ObjectHolder</code> which extends <code>UIComponent</code> that holds many children <code>UIComponents</code>. However, after using <code>addChild()</code> to add these children to <code>ObjectHolder</code>, its width and height remain zero.  Is it possible for the <code>UIComponent</code> to automatically expand to the size of its containing children components?</p>
  
  <pre><code>public class ObjectHolder extends UIComponent
  {       
      public function ObjectHolder()
      {
          var c1:UIComponent = new UIComponent();
          c1.graphics.beginFill( 0xffffff );
          c1.graphics.drawRect(0, 0, 100, 100);
          addChild( c1 );
          trace( this.width );  // Displays zero
      }
  }
  </code></pre>