title: Combobox is it open or not!
body: <p>I have a problem to determinate if my combobox is open or not.
  I've seen the same topic but that solution : <code>if(combobox.dropdown != null &amp;&amp; combobx.dropdown.visible)</code> doesn't work for me. It is always true. I can't find any component who is responsible for this such a simple operation.
  Thanks in advance.</p>