Using NestedScrollView, TabBarView and AutomaticKeepAliveClientMixin will scroll other scroll views in the tab. #36419
Description
Steps to Reproduce
- Change tab to Tab 2
- Scroll inner list in Tab 2
- Change tab to Tab 1
- Inner list in Tab 1 has also scrolled
If we switch tabs, States outside the screen will be disposed.
In many cases, loading data is a heavy process, so I want to keep States.
I am going to use AutomaticKeepAliveClientMixin for that.
However, with this combination of Widgets,
the scroll operation also affects the scroll view of other tabs.
- Without NestedScrollView, this does not occur
- Without AutomaticKeepAliveClientMixin, this does not occur
- When wantKeepAlive is false, this does not occur
import 'package:flutter/material.dart';
void main() => runApp(MaterialApp(home: MyApp()));
const _kTabs = ["Tab 1", "Tab 2"];
class MyApp extends StatefulWidget {
MyAppState createState() => MyAppState();
}
class MyAppState extends State<MyApp> with SingleTickerProviderStateMixin {
ScrollController scrollController = ScrollController();
@override
Widget build(BuildContext context) {
final Widget tabBar = TabBar(
tabs: _kTabs.map<Widget>((String name) => Tab(text: name)).toList());
return Scaffold(
body: DefaultTabController(
length: _kTabs.length,
child: NestedScrollView(
controller: scrollController,
headerSliverBuilder: (BuildContext context, bool innerBoxIsScrolled) {
return <Widget>[
SliverAppBar(
title: Text("Title"),
bottom: tabBar,
pinned: true,
forceElevated: innerBoxIsScrolled,
),
];
},
body: TabBarView(
children: _kTabs.map((String name) {
return Container(
key: PageStorageKey(name),
child: MyListView(),
);
}).toList(),
),
),
),
);
}
}
class MyListView extends StatefulWidget {
@override
_MyListViewState createState() => _MyListViewState();
}
class _MyListViewState extends State<MyListView> with AutomaticKeepAliveClientMixin {
@override
final bool wantKeepAlive = true;
@override
Widget build(BuildContext context) {
super.build(context);
return ListView.builder(
itemBuilder: (BuildContext context, int index) {
return ListTile(
title: Text('Item $index'),
);
},
);
}
}Logs
[✓] Flutter (Channel v1.7.8-hotfixes, v1.7.8+hotfix.3, on Mac OS X 10.14.4 18E226, locale ja-JP)
• Flutter version 1.7.8+hotfix.3 at /Applications/flutter
• Framework revision b712a172f9 (8 days ago), 2019-07-09 13:14:38 -0700
• Engine revision 54ad777fd2
• Dart version 2.4.0
[✓] Android toolchain - develop for Android devices (Android SDK version 28.0.3)
• Android SDK at /Users/najeira/Library/Android/sdk
• Android NDK at /Users/najeira/Library/Android/sdk/ndk-bundle
• Platform android-28, build-tools 28.0.3
• ANDROID_HOME = /Users/najeira/Library/Android/sdk
• ANDROID_SDK_ROOT = /Users/najeira/Library/Android/sdk
• 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-1248-b01)
• All Android licenses accepted.
[✓] Xcode - develop for iOS and macOS (Xcode 10.2)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 10.2, Build version 10E125
• CocoaPods version 1.7.4
[✓] iOS tools - develop for iOS devices
• ios-deploy 1.9.4
[✓] Chrome - develop for the web
• Chrome at /Applications/Google Chrome.app/Contents/MacOS/Google Chrome
[✓] Android Studio (version 3.3)
• Android Studio at /Applications/Android Studio.app/Contents
• Flutter plugin version 34.0.1
• Dart plugin version 182.5215
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1248-b01)
[✓] IntelliJ IDEA Ultimate Edition (version 2018.1)
• IntelliJ at /Applications/IntelliJ IDEA.app
• Flutter plugin version 31.1.1
• Dart plugin version 181.4203.498
[✓] VS Code (version 1.35.1)
• VS Code at /Applications/Visual Studio Code.app/Contents
• Flutter extension version 3.0.2
[✓] Connected device (5 available)
• SC 02H • 145faa87 • android-arm64 • Android 8.0.0 (API 26)
• HW 01K • LPF0218529000628 • android-arm64 • Android 8.1.0 (API 27)
• TetsuhiroのiPod touch • 8669364bb2135049086983a6bcc1f2db7cdd255e • ios • iOS 12.3.1
• macOS • macOS • darwin-x64 • Mac OS X 10.14.4 18E226
• web • web • web-javascript • Google Chrome 75.0.3770.142