class Activity: def __init__(self, stack, header_stack, builder, root, show_message, hide_message, update_message_progress, start_work, stop_work, switch_activity): self.widget = None self.stack = stack self.header_widget = None self.header_stack = header_stack self.menu_popover = None self.id = "" self.name = "" self.subtitle = "" self.builder = builder self.root = root self.show_message = show_message self.hide_message = hide_message self.update_message_progress = update_message_progress self.start_work = start_work self.stop_work = stop_work self.switch_activity = switch_activity self.on_init() def on_init(self): raise NotImplemented() def on_exit(self): return True def on_open(self, path): raise NotImplemented()