Repository: flutter
Issue: [Feature request] Scrolling outside of scrollable view should be somehow possible
Labels: c: new feature,framework,f: scrolling,a: mouse,P3,team-framework,triaged-framework

Currently it is only possible to scroll a scrollable view when I hover with mouse above the scrollable view.
I would like to scroll the `ListView` in the example below also when I scroll over the empty white space next to the scrollable view (when mouse is not hovered above the `ListView`).
The same should be possible to do either on web, desktop or mobile.

A realworld example is the Twitter app on web. The feed can be scrolled even when hovered outside.


<details>
<summary>Code example</summary>

```dart
void main() {
  runApp(MyApp());
}

class MyApp extends HookWidget {
  const MyApp({Key? key}) : super(key: key);

  @override
  Widget build(BuildContext context) {
    final scrollCtrl = useScrollController();

    return MaterialApp(
      scrollBehavior:
          ScrollConfiguration.of(context).copyWith(scrollbars: false),
      home: Material(
        child: Scrollbar(
          controller: scrollCtrl,
          child: Align(
            alignment: Alignment.topCenter,
            child: FractionallySizedBox(
              widthFactor: .8,
              child: Container(
                color: Colors.red,
                child: ListView(
                  controller: scrollCtrl,
                  children:
                      List.generate(100, (_) => ListTile(title: Text('Hello'))),
                ),
              ),
            ),
          ),
        ),
      ),
    );
  }
}
```

</details>



<details>
<summary>flutter doctor -v</summary>

```console
[✓] Flutter (Channel beta, 2.6.0-5.2.pre, on macOS 11.6 20G165 darwin-x64, locale en-GB)
    • Flutter version 2.6.0-5.2.pre at /Users/kristian/Documents/flutter
    • Upstream repository https://github.com/flutter/flutter.git
    • Framework revision 400608f101 (3 weeks ago), 2021-09-15 15:50:26 -0700
    • Engine revision 1d521d89d8
    • Dart version 2.15.0 (build 2.15.0-82.2.beta)

[✓] Android toolchain - develop for Android devices (Android SDK version 31.0.0)
    • Android SDK at /Users/kristian/Library/Android/sdk
    • Platform android-31, build-tools 31.0.0
    • Java binary at: /Applications/Android Studio.app/Contents/jre/Contents/Home/bin/java
    • Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7281165)
    • All Android licenses accepted.

[✓] Xcode - develop for iOS and macOS (Xcode 13.0)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • CocoaPods version 1.11.2

[✓] Chrome - develop for the web
    • Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome

[✓] Android Studio (version 2020.3)
    • Android Studio at /Applications/Android Studio.app/Contents
    • Flutter plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/9212-flutter
    • Dart plugin can be installed from:
      🔨 https://plugins.jetbrains.com/plugin/6351-dart
    • Java version OpenJDK Runtime Environment (build 11.0.10+0-b96-7281165)

[✓] VS Code (version 1.61.0)
    • VS Code at /Applications/Visual Studio Code.app/Contents
    • Flutter extension can be installed from:
      🔨 https://marketplace.visualstudio.com/items?itemName=Dart-Code.flutter

[✓] Connected device (1 available)
    • Chrome (web) • chrome • web-javascript • Google Chrome 94.0.4606.71

• No issues found!
```

</details>