code: def paintEvent(self, event):
          
          painter = QtGui.QPainter()
          painter.begin(self)
          try:
              palette = self.palette()
              clr = palette.color(palette.WindowText)
              clr.setAlpha(100)
              painter.setPen(clr)
              painter.setBrush(palette.color(palette.Window))
  
              if self._tabBar.isVisible():
                  painter.fillRect(0, 0, self.width() - 1, self.height() - 1, palette.color(palette.Button))
                  x = y = 3
                  w = self.width() - 7
                  h = self.height() - 7
              else:
                  x = y = 0
                  w = self.width() - 1
                  h = self.height() - 1
  
              painter.drawRect(x, y, w, h)
  
          finally:
              painter.end()
docs: Runs the paint event for this item.