title: How to change full screen mode during play video
body: <p>Now I am make video player. and try to make video screen size change.</p>
  
  <p>I find </p>
  
  <pre><code>MediaPlayer.OnVideoSizeChangedListener mSizeChangedListener =
      new MediaPlayer.OnVideoSizeChangedListener() {
  </code></pre>
  
  <p>but this is callback function. not direct call function.</p>
  
  <p>How to change video screen size?</p>