title: Detect focus on children component with react
body: <p>I have a parent component and in general I render input fields inside it.
  is there a way to know if the children input has focus?</p>
  <pre><code>&lt;Component&gt;
      &lt;input /&gt;
  &lt;/Component&gt;
  
  const Component = (props) =&gt; return (&lt;div className=&quot;nice&quot;&gt;{props.children}&lt;/div&gt;)
  </code></pre>