How to implement the pagination in flutter?

class PaginationDemo extends StatefulWidget {

  const PaginationDemo({Key? key}) : super(key: key);

  @override

  _PaginationDemoState createState() => _PaginationDemoState();

}

class _PaginationDemoState extends State<PaginationDemo> implements PaginationInterFace{

  PaginationPresenter? paginationPresenter;

  int limit=10;

  int page=1;

  List<AllPostData> allPosts=[];

  bool isLoading =false;

  @override

  void initState() {

 paginationPresenter=PaginationPresenter(this);

 setState(() {

 isLoading=true;

 });

 paginationPresenter?.doGetData(page.toString(),limit.toString());

  super.initState();

  }

  @override

  Widget build(BuildContext context) {

  returnScaffold(

  body: Stack(

  children: [

  NotificationListener<ScrollNotification>(

  onNotification: _onNotification,

  child: ListView.builder(

  itemCount:allPosts.length,

  itemBuilder:

  (BuildContext

  context,

  int index){

  return Container(

  margin: EdgeInsets.all(40),

  child: Text(allPosts[index].caption.toString()));

  }

  ),

  ),

  Visibility(

  visible: isLoading,

  child: Container(

  color: Colors.transparent,

  width:MediaQuery.of(context).size.width,

  height:MediaQuery.of(context).size.height,

  alignment: Alignment.center,

  child: const CircularProgressIndicator(

  valueColor:

  AlwaysStoppedAnimation<Color>(Colors.black54),

  ),

  ))

  ],

  ),

  );

  }

  bool _onNotification(ScrollNotification notification) {

  if (notification is ScrollEndNotification &&

  notification.metrics.pixels >=

  notification.metrics.maxScrollExtent - 200) {

  fetchData();

  }

  return true;

  }

  Future<void> fetchData() async {

  if (isLoading) return;

  setState(() {

  isLoading = true;

  });

  // Simulating API request with a delay

  await Future.delayed(Duration(seconds: 2));

  int count=page++;

  paginationPresenter?.doGetData(count.toString(),limit.toString());

  }

  @override

  onError(String msg, int status) {

  setState(() {

  isLoading=false;

  });

  if (kDebugMode) {

  print("onError${msg}");

  }

  }

  @override

  onSuccess(AllPostResponse allPostResponse) {

  setState(() {

  isLoading=false;

  });

  if (kDebugMode) {

  print("Success${allPostResponse.status}");

  }

  if (allPostResponse.status == 200) {

  allPosts.addAll(allPostResponse.data!);

  }

  }

}

/////// add parameter in int bool etc

Future<AllPostResponse> registerAPI(String isPhone,) async {

 Map<String, dynamic> requestBody = {

   "isPhone":false,};

  String jsonBody=json.encode(requestBody);

  // Set the headers

  Map<String, String> headers = {

  'Content-Type': 'application/json',

  };

  return _netUtil.postApi("", body: jsonBody,headers: headers).then((dynamic res) {

  return AllPostResponse.fromJson(res);

  });

  }