title: Qt QWidget as form, drop shadow effect
body: <p>I have a customized qwidget with no styles which plays the role of my main window. I want to add some shadow to my QWidget, but eventually the drop shadow effect</p>
  
  <pre><code>QGraphicsDropShadowEffect shadow;
  shadow.setBlurRadius(100.0);
  shadow.setOffset(0,0);
  .....
  </code></pre>
  
  <p>Just gives me some random black squares inside my form. Is there a way i can get my QWidget form to drop some shadow.</p>