activity property Null safety
protected">@protectedvisibleForTesting">@visibleForTesting
The currently operative ScrollActivity.
If the scroll position is not performing any more specific activity, the activity will be an IdleScrollActivity. To determine whether the scroll position is idle, check the isScrollingNotifier.
Call beginActivity to change the current activity.
Implementation
@protected
@visibleForTesting
ScrollActivity? get activity => _activity;