Flutter NotificationListener with ScrollNotification vs ScrollController

Question

There are two options to retrieve the scroll position for a CustomScrollView. The documentation states the following:

ScrollNotification and NotificationListener, which can be used to watch the scroll position without using a ScrollController.

So we have the following options:

1. NotificationListener with ScrollNotification
2. ScrollController

In which situation do you useNotificationListener with ScrollNotification vs ScrollController?

Thank you :)

Answer 1

If you're using NestedScrollView with nested scrollers, using a scrollController on the inner scrollers will break the link with NestedScrollView meaning NestedScrollView will no longer control the complete scrolling experience. To get information about the scroll positions of the inner scrollers in this case you would use a NotificationListener with ScrollNotification.

NotificationListener<ScrollNotification>(   child: ListView.builder(     itemCount: 10     itemBuilder: (BuildContext context, int index) {       return Text('Item $index');     },   ),   onNotification: (ScrollNotification scrollInfo) {     if (scrollInfo.metrics.pixels ==         scrollInfo.metrics.maxScrollExtent) {       onLoadMore();     }   }, ); 

Related Answer here.