title: How to access a child object from parent component (JFrame)
body: <p>I have a top level container (JFrame) that contains two JPanels. One of the JPanel children has a property that will change and that needs to trigger an update on one of the other JPanel components (a JProgressBar).</p>
  
  <p>How can I access this component from the JPanel where the property change is triggered? If this is not the correct way to do it, is there any other method to propagate the property change to it?</p>