code: def handle_left_double_click(self, info):
          
          if (self.double_click_focus == False):  # turn focus on
              print(self.pre, "handle_left_double_click: focus on")
              self.cb_focus()
          else:  # turn focus off
              print(self.pre, "handle_left_double_click: focus off")
              self.cb_unfocus()
          self.double_click_focus = not(
              self.double_click_focus)
docs: Whatever we want to do, when the VideoWidget has been double-clicked with the left button