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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:
In which situation do you useNotificationListener with ScrollNotification vs ScrollController?
Thank you :)
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A ScrollController is a Listenable. It notifies its listeners whenever any of the attached ScrollPositions notify their listeners (i.e. whenever any of them scroll). It does not notify its listeners when the list of attached ScrollPositions changes. Typically used with ListView, GridView, CustomScrollView.
You need to add a padding to your ListView in order to offset the scroll boundary into the screen.
The pixels value determines the scroll offset that the scroll view uses to select which part of its content to display. As the user scrolls the viewport, this value changes, which changes the content that is displayed. The ScrollPosition applies physics to scrolling, and stores the minScrollExtent and maxScrollExtent.
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.
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