watch method
Implementation
@override
T watch(BuildContext context) {
if (_watchers[context] == null) {
final element = context as Element;
final subscription = listen((_) => element.markNeedsBuild());
void onObjectEvent(ObjectEvent event) {
if (event is! ObjectDisposed || event.object != context) return;
subscription.cancel();
_watchers.remove(context);
FlutterMemoryAllocations.instance.removeListener(onObjectEvent);
}
FlutterMemoryAllocations.instance.addListener(onObjectEvent);
}
return _getValue();
}