ScrollPosition from ScrollController always reports scrolling is true #20819
Description
Steps to Reproduce
When running following code ScrollPosition.isScrollingNotifier is always true, even if there is no scrolling underway (scrolling ended). According to docs it should be:
/// This notifier's value is true if a scroll is underway and false if the scroll
/// position is idle.
///
/// Listeners added by stateful widgets should be removed in the widget's
/// [State.dispose] method.
final ValueNotifier<bool> isScrollingNotifier = new ValueNotifier<bool>(false);Code:
import 'package:flutter/material.dart';
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 = ${controller.position.isScrollingNotifier.value}');
});
super.initState();
}
@override
void dispose() {
controller.dispose();
super.dispose();
}
@override
Widget build(BuildContext context) {
return ListView.builder(
controller: controller,
itemCount: 20,
itemBuilder: (BuildContext context, int index) {
return Container(
margin: EdgeInsets.only(top: 16.0),
height: 84.0,
decoration: BoxDecoration(
borderRadius: BorderRadius.circular(16.0),
color: Colors.amberAccent[100],
),
child: Center(child: Text('$index')),
);
},
);
}
}
⇒ flutter doctor -v
[✓] Flutter (Channel beta, v0.5.1, on Mac OS X 10.13.6 17G65, locale en-DE)
• Flutter version 0.5.1 at /Users/someone/Documents/projects/flutter/sdk/flutter
• Framework revision c7ea3ca377 (3 months ago), 2018-05-29 21:07:33 +0200
• Engine revision 1ed25ca7b7
• Dart version 2.0.0-dev.58.0.flutter-f981f09760
[✓] Android toolchain - develop for Android devices (Android SDK 28.0.2)
• Android SDK at /Users/someone/Library/Android/sdk
• Android NDK location not configured (optional; useful for native profiling support)
• Platform android-28, build-tools 28.0.2
• Java binary at: /Applications/Android Studio.app/Contents/jre/jdk/Contents/Home/bin/java
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b01)
• All Android licenses accepted.
[✓] iOS toolchain - develop for iOS devices (Xcode 9.4.1)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 9.4.1, Build version 9F2000
• ios-deploy 1.9.2
• CocoaPods version 1.5.3
[✓] Android Studio (version 3.1)
• Android Studio at /Applications/Android Studio.app/Contents
• Flutter plugin version 27.1.1
• Dart plugin version 173.4700
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b01)
[✓] IntelliJ IDEA Ultimate Edition (version 2018.1.5)
• IntelliJ at /Applications/IntelliJ IDEA.app
• Flutter plugin version 26.0.2
• Dart plugin version 181.4892.1
[!] VS Code (version 1.26.1)
• VS Code at /Applications/Visual Studio Code.app/Contents
• Flutter extension not installed; install from
https://marketplace.visualstudio.com/items?itemName=Dart-Code.flutter
[✓] Connected devices (1 available)
• Android SDK built for x86 • emulator-5554 • android-x86 • Android 9 (API 28) (emulator)