title: Qt: Blur behind window
body: <p>I have 2 widgets:<br>
  <a href="https://i.stack.imgur.com/yD4Tb.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/yD4Tb.png" alt="widgets"></a>
  <br>
  One of them is background(semi-transparent), second contains other widgets(without background)<br>
  Can I make a blur behind window like this? <br><a href="https://i.stack.imgur.com/kj5d0.png" rel="nofollow noreferrer"><img src="https://i.stack.imgur.com/kj5d0.png" alt="enter image description here"></a></p>