new_contents: from ginga.qtw.ImageViewCanvasQt import ImageViewCanvas
  
  
  class PDSImageViewCanvas(ImageViewCanvas):
  
      def __init__(self):
          super(PDSImageViewCanvas, self).__init__(render='widget')
          self._subviews = []
          self.set_autocut_params('zscale')
          self.enable_autozoom('override')
          self.enable_autocuts('override')
          self.set_bg(0, 0, 0)
          self.ui_setActive(True)
  
      def add_subview(self, subview):
          self._subviews.append(subview)
  
      def cut_levels(self, cut_low, cut_high):
          super(PDSImageViewCanvas, self).cut_levels(cut_low, cut_high)
          for subview in self._subviews:
              subview.cut_levels(cut_low, cut_high)
  
      def transform(self, flip_x, flip_y, swap_xy):
          super(PDSImageViewCanvas, self).transform(flip_x, flip_y, swap_xy)
          for subview in self._subviews:
              subview.transform(flip_x, flip_y, swap_xy)
  
subject: Create subclass of ImageViewCanvas for pdsspect