title: Kivy refresh layout (Async Loading)
body: <p>I have a ListView that where each item has a AsyncImage and a Label. While the images load it shows the layout with gaps between each item. </p>
  
  <pre><code>-------
  
  Item
  
  -------
  
  Item 
  
  -------
  </code></pre>
  
  <p>When the first interaction happens (a scroll occurs), the layout refreshes and the gaps disappear.</p>
  
  <pre><code>-------
  Item    
  -------  
  Item 
  -------
  </code></pre>
  
  <p>I'd really like to have the layout refresh when an image finishes loading. How do I refresh a layout?</p>