def METHOD_NAME(self, event):
    #
    # Use the GraphicsView contentsRect size and not it's viewport
    # contentsRect size because depending on the zoom scroll bars
    # will appear and disappear throwing off the calculation.
    #
    #viewport_rect = self.viewport().contentsRect()
    viewport_rect = self.contentsRect()
    self.viewport_min = viewport_rect.width() if (viewport_rect.width() < viewport_rect.height())\
                        else viewport_rect.height()
    self.min_scale = self.calcScale(self.chip_max)
    if (self.display_scale < self.min_scale):
        self.display_scale = self.min_scale
    super().METHOD_NAME(event)