ReorderableListView#onReorder passes an unexpected new index #24786
Description
The ReorderableListView widget seems to passing an incorrect newIndex parameter when triggering the onReorder handler.
Steps to Reproduce
Here's a demo of the behavior as described in the below steps:
https://gist.github.com/chrislambe/b9aa44a5f3d3cc7dc6fdb24fb221982d
- Create an app with a
ReorderableListViewwidget and dummy data. - In the
onReorderhandler, print out the new index. - Drag the item in the 0 index position down until it swaps positions with the item in 1 index then, without releasing the item, drag it back to its original position and release. Note that the printed new index is
1instead of0, even though the intent was to drop the item in its original position. - Drag the item to the bottom of the list and release. Note that the new index is 1 greater than the bounds of the
childrenList.
Logs
Result of above step 3
flutter: oldIndex: 0, newIndex: 1, length: 4
Result of above step 4
flutter: oldIndex: 0, newIndex: 4, length: 4
flutter analyze
$ flutter analyze
Analyzing on_reorder_broken...
No issues found! (ran in 2.3s)
flutter doctor -v
$ flutter doctor -v
[✓] Flutter (Channel dev, v0.11.9, on Mac OS X 10.14.1 18B75, locale en-US)
• Flutter version 0.11.9 at /Applications/flutter
• Framework revision d48e6e433c (7 days ago), 2018-11-20 22:05:23 -0500
• Engine revision 5c8147450d
• Dart version 2.1.0 (build 2.1.0-dev.9.4 f9ebf21297)
[✓] Android toolchain - develop for Android devices (Android SDK 27.0.3)
• Android SDK at /Users/chris/Library/Android/sdk
• Android NDK location not configured (optional; useful for native profiling support)
• Platform android-27, build-tools 27.0.3
• 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-915-b08)
• All Android licenses accepted.
[!] iOS toolchain - develop for iOS devices (Xcode 10.1)
• Xcode at /Applications/Xcode.app/Contents/Developer
• Xcode 10.1, Build version 10B61
✗ Verify that all connected devices have been paired with this computer in Xcode.
If all devices have been paired, libimobiledevice and ideviceinstaller may require updating.
To update with Brew, run:
brew update
brew uninstall --ignore-dependencies libimobiledevice
brew uninstall --ignore-dependencies usbmuxd
brew install --HEAD usbmuxd
brew unlink usbmuxd
brew link usbmuxd
brew install --HEAD libimobiledevice
brew install ideviceinstaller
• ios-deploy 1.9.2
✗ ios-deploy out of date (1.9.4 is required). To upgrade with Brew:
brew upgrade ios-deploy
• CocoaPods version 1.5.3
[✓] Android Studio (version 3.0)
• Android Studio at /Applications/Android Studio.app/Contents
• Flutter plugin version 23.2.1
• Dart plugin version 171.4424
• Java version OpenJDK Runtime Environment (build 1.8.0_152-release-915-b08)
[✓] VS Code (version 1.29.1)
• VS Code at /Applications/Visual Studio Code.app/Contents
• Flutter extension version 2.20.0
[✓] Connected device (2 available)
• moto x4 • ZY224KS2L3 • android-arm64 • Android 8.1.0 (API 27)
• iPhone XR • F2133438-AFB5-421D-9CC0-36FD9FE97D28 • ios • iOS 12.1 (simulator)
! Doctor found issues in 1 category.
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Important issues not at the top of the work listA truly polished experienceBackwards-incompatible API changesAffects or could affect many people, though not necessarily a specific customer.flutter/packages/flutter/material repository.Viewports, list views, slivers, etc.Found to occur in 1.26flutter/packages/flutter repository. See also f: labels.The issue has been confirmed reproducible and is ready to work on