title: When to use the UtteranceProgressListener
body: <p>I have a FrameLayout with two ImageButtons (<em>Play</em>, <em>Stop</em>). By default </p>
  
  <p><em>Play</em> button is <code>VISIBLE</code>, <em>Stop</em> button is <code>GONE</code></p>
  
  <p>Clicking the <em>Play</em> starts the TTS Engine which reads the text. On Completion of reading the text, I want to set the Visibility of</p>
  
  <p>Play to <code>GONE</code>, Stop to <code>VISIBLE</code></p>
  
  <p>Should I use the UtteranceProgressListener to serve the purpose? If not,</p>
  
  <ul>
  <li>How can I perform the above action?</li>
  <li>What is the purpose of UtteranceProgressListener?</li>
  </ul>