docs: def paintEvent(self, event):
          """
          Paints the background for the dock toolbar.
          
          :param      event | <QPaintEvent>
          """
          x = 1
          y = 1
          w = self.width()
          h = self.height()
          
          clr_a = QColor(220, 220, 220)
          clr_b = QColor(190, 190, 190)
          
          grad = QLinearGradient()
          grad.setColorAt(0.0, clr_a)
          grad.setColorAt(0.6, clr_a)
          grad.setColorAt(1.0, clr_b)
          
          # adjust the coloring for the horizontal toolbar
          if self.position() & (self.Position.North | self.Position.South):
              h = self.minimumPixmapSize().height() + 6
              
              if self.position() == self.Position.South:
                  y = self.height() - h
                  grad.setStart(0, y)
                  grad.setFinalStop(0, self.height())
              else:
                  grad.setStart(0, 0)
                  grad.setFinalStart(0, h)
          
          # adjust the coloring for the vertical toolbar
          if self.position() & (self.Position.East | self.Position.West):
              w = self.minimumPixmapSize().width() + 6
              
              if self.position() == self.Position.West:
                  x = self.width() - w
                  grad.setStart(x, 0)
                  grad.setFinalStop(self.width(), 0)
              else:
                  grad.setStart(0, 0)
                  grad.setFinalStop(w, 0)
          
          with XPainter(self) as painter:
              painter.fillRect(x, y, w, h, grad)
              
              # show the active action
              action = self.selectedAction()
              if action is not None and \
                 not self.currentAction() and \
                 not self._animating:
                  for lbl in self.actionLabels():
                      if lbl.action() != action:
                          continue
                      
                      geom = lbl.geometry()
                      size = lbl.pixmapSize()
                      
                      if self.position() == self.Position.North:
                          x = geom.left()
                          y = 0
                          w = geom.width()
                          h = size.height() + geom.top() + 2
                      
                      elif self.position() == self.Position.East:
                          x = 0
                          y = geom.top()
                          w = size.width() + geom.left() + 2
                          h = geom.height()
                      
                      painter.setPen(QColor(140, 140, 40))
                      painter.setBrush(QColor(160, 160, 160))
                      painter.drawRect(x, y, w, h)
                      break