import 'package:flutter/material.dart';

void main() {
  runApp(MaterialApp(home: MyListView()));
}
class MyListView extends StatefulWidget {
  @override
  _MyListViewState createState() => _MyListViewState();
}

class _MyListViewState extends State<MyListView> {
  final ScrollController controller = ScrollController();

  @override
  void initState() {
    controller.addListener(() {
      // always prints "scrolling = true"
      print('scrolling = ${controller.position.isScrollingNotifier.value}');
    });
    super.initState();
  }

  @override
  void dispose() {
    controller.dispose();
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(body: ListView.builder(
      controller: controller,
      itemCount: 20,
      itemBuilder: (BuildContext context, int index) {
        return ListTile( 
          title: Text('$index'),
        );
      },
    ),
    );
  }
}