code: def _drawForeground(self, scene, painter, rect):
          
          rect = scene.sceneRect()
          if scene == self.uiChartVIEW.scene():
              self.renderer().drawForeground(painter,
                                             rect,
                                             self.showGrid(),
                                             self.showColumns(),
                                             self.showRows())
docs: Draws the backgroud for a particular scene within the charts.
          
          :param      scene   | <XChartScene>
                      painter | <QPainter>
                      rect    | <QRectF>