flutter_gallery tabs_demo.dart: have problem when the tabs' num exceed 2. #18832
Description
I just add a _Page to _allPages(line 27) base on flutter_gallery's tabs_demo.dart.
See https://gist.github.com/marekchen/2adf5d03e845e9fe69ffdbc74533eba4
Steps to Reproduce
problem 1:
- click the third tab
- scroll up list(third tab)
- click the second tab, found that this list also scroll up
problem 2:(restart this page before do the following)
- scroll up list(first tab)
- click the second tab
- scroll down list(second tab)
- click the first tab, found that the first tab restored to it's original
Logs
no logs
[√] Flutter (Channel master, v0.5.6-pre.39, on Microsoft Windows [Version 10.0.17134.112], locale zh-CN)
• Flutter version 0.5.6-pre.39 at C:\develope\flutter\flutter
• Framework revision a18f5e84a1 (6 days ago), 2018-06-20 20:23:51 -0400
• Engine revision 549c855e89
• Dart version 2.0.0-dev.63.0.flutter-4c9689c1d2
[√] Android toolchain - develop for Android devices (Android SDK 27.0.3)
• Android SDK at C:\Android\android-sdk
• Android NDK location not configured (optional; useful for native profiling support)
• Platform android-27, build-tools 27.0.3
• ANDROID_HOME = C:\Android\android-sdk
• Java binary at: C:\Android\Android-Studio3\jre\bin\java
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b02)
• All Android licenses accepted.
[√] Android Studio (version 2.3)
• Android Studio at C:\Android\android-studio
X Flutter plugin not installed; this adds Flutter specific functionality.
X Dart plugin not installed; this adds Dart specific functionality.
• Java version OpenJDK Runtime Environment (build 1.8.0_112-release-b06)
[√] Android Studio (version 3.1)
• Android Studio at C:\Android\Android-Studio3
• Flutter plugin version 25.0.1
• Dart plugin version 173.4700
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-1024-b02)
[!] IntelliJ IDEA Ultimate Edition (version 2017.3)
• IntelliJ at C:\Program Files\JetBrains\IntelliJ IDEA 2017.3.4
X Flutter plugin not installed; this adds Flutter specific functionality.
X Dart plugin not installed; this adds Dart specific functionality.
• For information about installing plugins, see
https://flutter.io/intellij-setup/#installing-the-plugins
[√] VS Code, 64-bit edition (version 1.24.1)
• VS Code at C:\Program Files\Microsoft VS Code
• Flutter extension version 2.14.0
[√] Connected devices (1 available)
• ONEPLUS A6000 • 5e5530a6 • android-arm64 • Android 8.1.0 (API 27)
! Doctor found issues in 1 category.