title: How to show QGLWidget in full screen?
body: <p>I have a QGLWidget as part of the UI of my application. It is <strong>NOT a central widget</strong>, there are a lot of others widgets around it. I want to show it full screen on user clicks the button. Similar functionality like on youtube video flash player.</p>
  
  <p>I have tried to use <strong>showFullScreen</strong> with no effect. </p>
  
  <p>I have read <a href="https://stackoverflow.com/questions/4046004/how-to-fullscreen-a-qglwidget">how-to-fullscreen-a-qglwidget</a> and <a href="https://stackoverflow.com/questions/1246825/fullscreen-widget">fullscreen-widget</a>, but they suggest using showFullScreen.</p>
  
  <p>Qt documentation states that for using showFullScreen widget must be an independent window. So I assume there should be some trick for this. </p>