Pagination in Flutter App without using a package

pagination.dart

import 'package:flutter/material.dart';

class PaginatedScreen extends StatefulWidget {

  @override
  _PaginatedScreenState createState() => _PaginatedScreenState();
}

class _PaginatedScreenState extends State<PaginatedScreen> {
  int page = 1;
  List<String> items = ['item 1', 'item 2','item 3', 'item 4','item 5', 'item 6','item 7', 'item 8','item 9', 'item 10', ];
  bool isLoading = false;

  Future _loadData() async {
    // perform fetching data delay
    await new Future.delayed(new Duration(seconds: 1));

    print("loading more data");

    setState(() {
      items.addAll( ['item 11', 'item 12','item 13', 'item 14','item 15', 'item 16','item 17', 'item 18','item 19', 'item 20', ]);
      isLoading = false;
    });
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      backgroundColor: Colors.white,
      appBar: AppBar(
        title: Text('Sample',style: TextStyle(color: Colors.black),),
      ),
      body: Column(
        children: <Widget>[
          Expanded(
            child: NotificationListener<ScrollNotification>(
              onNotification: (ScrollNotification scrollInfo) {
                if (!isLoading && scrollInfo.metrics.pixels ==
                    scrollInfo.metrics.maxScrollExtent) {
                  _loadData();
                  // start loading data
                  setState(() {
                    isLoading = true;
                  });
                }

                return true;
              },
              child: ListView.builder(
                itemCount: items.length,
                itemBuilder: (context, index) {
                  return ListTile(
                    title: Text('${items[index]}',style: TextStyle(color: Colors.black,fontSize: 14),),
                  );
                },
              ),
            ),
          ),
          Visibility(
            visible: isLoading,
            child: Card(
              shape: CircleBorder(),
              child: Container(
                padding: EdgeInsets.all(5),
                child: Center(
                  child: SizedBox(
                    child: CircularProgressIndicator(
                      valueColor:
                      AlwaysStoppedAnimation<Color>(
                        Colors.lightGreen,
                      ),
                      strokeWidth: 2.0,
                      backgroundColor:
                      Colors.transparent,
                    ),
                    height: 20,
                    width: 20,
                  ),
                ),
              ),
            ),
          )
        ],
      ),
    );
  }
}