+#!/usr/bin/env python3
-class trigger(object):
+from abc import ABC, abstractmethod
+from typing import List, Tuple, Optional
+
+
+class trigger(ABC):
"""Base class for something that can trigger a page becomming active."""
PRIORITY_HIGH = 100
PRIORITY_NORMAL = 50
PRIORITY_LOW = 0
- def get_triggered_page_list(self):
- return None
+ @abstractmethod
+ def get_triggered_page_list(self) -> Optional[List[Tuple[str, int]]]:
+ pass