Infinite scroll with CustomScrollView Flutter - flutter

Question

I would like to know how can I implement an infinite scroll with CustomScrollView in Flutter.
On init, I have the call to load the items, it works. But, I would like to launch again the call on provider to re-load again, but I can re-launch because I don't have a context to call the provider in the onScroll function.
Currently, I have this :
class _FeedScreenState extends State<FeedScreen> {
final _scrollController = ScrollController();
double _prevScrollPos = 0.0;
_onScroll() {
double maxScroll = _scrollController.position.maxScrollExtent;
double currentScrollPos = _scrollController.position.pixels;
double delta = 200.0;
if (maxScroll - currentScrollPos <= delta && _prevScrollPos - currentScrollPos < 0) {
print('load... I would like to call my provider to load the others posts with addPost()');
//Provider.of<GlobalFeeds>(context, listen: false).addPost();
// to fix the unlimited call on onScroll function
_scrollController.jumpTo(_scrollController.position.pixels);
}
_prevScrollPos = currentScrollPos;
}
_addPost(context) {
Provider.of<GlobalFeeds>(context, listen: false).addPost();
}
#override
void initState() {
_scrollController.addListener(_onScroll);
Timer.run(() {
_addPost(context);
});
super.initState();
}
#override
void dispose() {
_scrollController.dispose();
super.dispose();
}
#override
Widget build(BuildContext context) {
final globalFeeds = Provider.of<GlobalFeeds>(context);
final posts = globalFeeds.posts;
return Scaffold(
body: CustomScrollView(
controller: _scrollController,
slivers: [
SliverAppBar(
...
),
SliverList(
delegate: SliverChildBuilderDelegate((context, index) {
final Post post = posts[index];
return PostContainer(post: post);
},
childCount: posts.length,
),
),
],
)
);
}
}
To init my list, I call in initState() :
Timer.run(() {
_addPost(context);
});
I don't know if it's a good practice. Do you have an idea how can I implement this functionality, to have a context in onScroll function or to have a better solution ?

Answer 1

try using
itemBuilder: (index, context) {
if(items.length < index) {
return items[index-1];
}
else {
return FutureBuilder(/*...*/); // your loading widget which
} // becomes the new item once loaded
}
also get rid of the childCount.