NotificationListener

home.dart

import 'dart:math';

import 'package:flutter/material.dart';

class Home extends StatefulWidget {
  const Home({Key? key}) : super(key: key);

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

class SimpleBloc extends StatelessWidget {
  const SimpleBloc({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    return Container(
      alignment: Alignment.center,
      color: Colors.primaries[Random().nextInt(Colors.primaries.length)],
      width: double.maxFinite,
      height: 100,
    );
  }
}

class _HomeState extends State<Home> {
  ScrollController controller = ScrollController();

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

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: ListView(
        controller: controller,
        children: [
          const SimpleBloc(),
          const SimpleBloc(),
          const SimpleBloc(),
          Container(
            height: 350,
            padding: const EdgeInsets.all(16),
            child: NotificationListener<OverscrollNotification>(
              onNotification: (OverscrollNotification value) {
                if (value.overscroll < 0 && controller.offset + value.overscroll <= 0) {
                  if (controller.offset != 0) {
                    controller.jumpTo(0);
                  }
                } else if (controller.offset + value.overscroll >= controller.position.maxScrollExtent) {
                  if (controller.offset != controller.position.maxScrollExtent) {
                    controller.jumpTo(controller.position.maxScrollExtent);
                  }
                } else {
                  controller.jumpTo(controller.offset + value.overscroll);
                }
                return true;
              },
              child: ListView(
                children: const [
                  SimpleBloc(),
                  SimpleBloc(),
                  SimpleBloc(),
                  SimpleBloc(),
                  SimpleBloc(),
                  SimpleBloc(),
                ],
              ),
            ),
          ),
          const SimpleBloc(),
          const SimpleBloc(),
          const SimpleBloc(),
        ],
      ),
    );
  }
}