code: def _calc_preview_ypos(self):
          "Calculates the previews positions on canvas"
  
          y = 10
          min_y = [y]
          for k, p in self.previews.items():
              y += p.height() + self.padding
              min_y.append(y)
          return min_f _calc_preview_ypos(self):
          "Calculates the previews positions on canvas"
  
          y = 10
          min_y = [y]
          for k, p in self.previews.items():
              y += p.height() + self.padding
              min_y.append(y)
          return min_y
docs: Calculates the previews positions on canvas