scroll-nots-without-scrolling.dart

import 'package:flutter/material.dart';

void main() => runApp(const App());

class App extends StatelessWidget {
  static const title = 'Flutter App';

  const App({Key? key}) : super(key: key);
  @override
  Widget build(BuildContext context) => const MaterialApp(
        title: title,
        home: HomePage(),
      );
}

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

  @override
  State<HomePage> createState() => _HomePageState();
}

class _HomePageState extends State<HomePage> {
  int _count = 0;

  @override
  Widget build(BuildContext context) => Scaffold(
        appBar: AppBar(title: const Text(App.title)),
        body: Scrollbar(
          isAlwaysShown: true,
          child: ListView(
            shrinkWrap: true,
            children: [
              for (var i = 0; i != _count; ++i) ListTile(title: Text('item $i'))
            ],
          ),
        ),
        floatingActionButton: Row(
          mainAxisAlignment: MainAxisAlignment.end,
          children: [
            Padding(
              padding: const EdgeInsets.all(8.0),
              child: FloatingActionButton(
                onPressed: () => setState(() => _count--),
                child: const Text('-'),
              ),
            ),
            Padding(
              padding: const EdgeInsets.all(8.0),
              child: FloatingActionButton(
                onPressed: () => setState(() => _count++),
                child: const Text('+'),
              ),
            ),
          ],
        ),
      );
}

Hi Chris, your manual scrollbar has isAlwaysShown: true, the automatically applied one on desktop does not have this set by default, which is why you cannot see it without scrolling.

You can set this using the theme, and I believe the automatically applied scrollbar will show up as you expect:

class App extends StatelessWidget {
  static const title = 'Flutter App';

  const App({Key? key}) : super(key: key);
  @override
  Widget build(BuildContext context) =>  MaterialApp(
        title: title,
        home: HomePage(),
        theme: ThemeData(scrollbarTheme: ScrollbarThemeData(isAlwaysShown: true))
      );
}