title: In React, how to detect if the mouse is hovering an element?
body: <pre><code>const div_ref = useRef();
  
  &lt;div ref={div_ref} /&gt;
  </code></pre>
  <p>What are the properties of <code>div_ref</code> that I can use to find out if the mouse is hovering over <code>div_ref</code>?</p>