title: Pyside QT Background window translucent not working windows
body: <p>I developped a program in Python under Linux, everything works, but not in windows.. I'm on W10.</p>
  
  <p>I have a window with Pyside Qt, with on the left a frame with Qpushbutton on a grey background and on the rigth, an png image empty, to get a translucent background. I use this to plot points in this area by visualising other windows on the back.</p>
  
  <p>Here is my code</p>
  
  <pre><code>    def initUI(self):
  
      # Taille Fenêtre
      self.resize(500, 500)
  
      # Centrage + plein ecran
      size_ecran = QDesktopWidget().screenGeometry()
      size_fenetre = self.geometry()
      self.move((size_ecran.width()-size_fenetre.width())/2, (size_ecran.height()-size_fenetre.height())/2)
      # self.resize(size_ecran.width(), size_ecran.height())
  
      hbox = QHBoxLayout(self)
      vbox1 = QVBoxLayout()
      vbox2 = QVBoxLayout()
  
      self._frameLeft = QFrame(self)
      self._frameLeft.setFrameShape(QFrame.StyledPanel)
  
      # Calcul Courbe
      self._btnCurve = QPushButton(listeNameButton[0])
      self._btnCurve.setIcon(QIcon('ico/curve.png'))
      self._btnCurve.setIconSize(QSize(55,55))
      self._btnCurve.clicked.connect(self.evtCurve)   
  
      vbox1.addWidget(self._btnCurve)
  </code></pre>
  
  <p>This works on Linux (Ubuntu), not in Windows : the right part is black.
  I tried with self.opacityWindow, it works but the whole window is translucent not only the right side. Do you have any idea ?</p>
  
  <p>Thanks</p>
  
  <pre><code>    # Transparence
      size_fenetre = self.geometry()
      size_button = self._btnCurve.geometry()
  
      self._frameLeft.setStyleSheet("background-color:grey;")
      self._frameLeft.setStyleSheet("border: none;")
      self._frameLeft.setGeometry(0,0,size_button.width()+50, size_fenetre.height())
  
      self._draw = QLabel(self)
      self._drawempty = QPixmap("ico/imgvide.png")
      self._drawempty =self._drawempty.scaled((size_button.width())*1.5,size_fenetre.height())
      self._draw.setStyleSheet("background:transparent;")
      self._draw.setPixmap(self._drawempty)
      vbox2.addWidget(self._draw)
  
      hbox.addLayout(vbox1)
      hbox.addLayout(vbox2)
      self.setLayout(hbox)
      self.setAttribute(Qt.WA_TranslucentBackground)
  </code></pre>
  
  <p>I've just a blackbackground with Qt.WA_TranslucentBackground, not translucent. How do manage this ?</p>