smooth scrolling for pageview

main.dart

/// [https://github.com/flutter/flutter/issues/35687]

import 'package:flutter/material.dart';
import 'package:flutter/gestures.dart';

void main() => runApp(MyApp());

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

  @override
  Widget build(BuildContext context) => MaterialApp(
        home: const MyHomePage(),
      );
}
final PageController _pageController = PageController();
class MyHomePage extends StatelessWidget {
  const MyHomePage({Key key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    // Local dragStartDetail.
    DragStartDetails dragStartDetails;
    // Current drag instance - should be instantiated on overscroll and updated alongside.
    Drag drag;
    return DefaultTabController(
      length: 2,
      child: Scaffold(
        appBar: AppBar(
          title: const Center(child: Text('use the mouse wheel to scroll')),
          bottom: TabBar(
            tabs: const [
              Center(child: Text('ScrollView')),
              Center(child: Text('PageView'))
            ],
          ),
        ),
        body: TabBarView(
          children: [
            SingleChildScrollView(
              child: Column(
                children: [
                  for (int i = 0; i < 10; i++)
                    Container(
                      height: MediaQuery.of(context).size.height,
                      child: const Center(
                        child: FlutterLogo(size: 80),
                      ),
                    ),
                ],
              ),
            ),
            NotificationListener(
              onNotification: (notification) {
                if (notification is ScrollStartNotification) {
                  dragStartDetails = notification.dragDetails;
                }
                if (notification is ScrollUpdateNotification) {
                  drag = _pageController.position.drag(dragStartDetails, () {});
                  drag.update(notification.dragDetails);
                }
                if (notification is ScrollEndNotification) {
                  drag?.cancel();
                }
                return true;
              },
              child: PageView(
                scrollDirection: Axis.vertical,
                controller: _pageController,
                children: [
                  for (int i = 0; i < 10; ++i)
                    const Center(
                      child: FlutterLogo(size: 80),
                    ),
                ],
              ),
            ),
          ],
        ),
      ),
    );
  }
}