+ return bool(self.callbacks[event])
+
+ def set_selectable_callback(self, func):
+ self._is_selectable_func = func
+
+ def is_selectable(self):
+ """Return False if this widget isn't selectable by SelectorWidget."""
+ if self._is_selectable_func is not None:
+ return self._is_selectable_func()
+ else:
+ return True