title: How to react on a change of visibility of children?
body: <p>I have different container items and I would like to make not visible when all of their children are not visible.</p>
  
  <p>Dynamically, some code is parsing all the items recursively and set them visible or not visible depending on some filter (like a search input). The container items are ignored by this filtering.</p>
  
  <p>After that filtering, how can I detect the visibility has changed and update my container items accordingly ?</p>
  
  <p>So far I have this code but I need this to be executed every time the children visibility is changed :</p>
  
  <pre><code>visible: visibleChildren.size &gt; 0
  </code></pre>