onTapUp not triggered after app is suspended and re-opened

[miguelcmedeiros]

Steps to Reproduce

I am seeing the following behaviour when the app is suspended (for instance, when receiving a phone call) during a gesture (long tapping or dragging) and then is re-opened:

1. Tap down on the following widget -> prints "onTapDown"
2. Press home button (could be receive phone call)
3. Re-open app -> "onTapUp" is never printed

class DemoScreen extends StatelessWidget {
  @override
  Widget build(BuildContext context) => Center(
        child: Container(
          width: 300.0,
          height: 300.0,
          color: Colors.blue,
          child: Center(
            child: GestureDetector(
              onTapDown: (_) => print('onTapDown'),
              onTapUp: (_) => print('onTapUp'),
              child: Container(
                width: 100.0,
                height: 100.0,
                color: Colors.orange,
              ),
            ),
          ),
        ),
      );
}

This is a problem when you have some behaviour associated with the gesture, like an animation. The consequence here is that once the app is re-opened, the animation will be in the end state, which can be quite strange for the user.

I would expect that on such case, any on-going gesture gets completed. Is this the right expectation?

Flutter doctor

flutter doctor -v
[✓] Flutter (Channel unknown, v0.10.2, on Mac OS X 10.13.6 17G65, locale en-NL)
    • Flutter version 0.10.2 at /Users/user/IdeaProjects/hue_blue/flutter
    • Framework revision d8cbb80206 (4 weeks ago), 2018-10-26 01:30:21 -0400
    • Engine revision 6c2ade9fa2
    • Dart version 2.1.0-dev.8.0.flutter-bf26f760b1

[✗] Android toolchain - develop for Android devices
    ✗ Unable to locate Android SDK.
      Install Android Studio from: https://developer.android.com/studio/index.html
      On first launch it will assist you in installing the Android SDK components.
      (or visit https://flutter.io/setup/#android-setup for detailed instructions).
      If Android SDK has been installed to a custom location, set $ANDROID_HOME to that location.
      You may also want to add it to your PATH environment variable.


[✓] iOS toolchain - develop for iOS devices (Xcode 10.1)
    • Xcode at /Applications/Xcode.app/Contents/Developer
    • Xcode 10.1, Build version 10B61
    • ios-deploy 2.0.0
    • CocoaPods version 1.5.3

[!] Android Studio (not installed)
    • Android Studio not found; download from https://developer.android.com/studio/index.html
      (or visit https://flutter.io/setup/#android-setup for detailed instructions).

[✓] IntelliJ IDEA Community Edition (version 2018.1.6)
    • IntelliJ at /Applications/IntelliJ IDEA CE.app
    • Flutter plugin version 30.0.1
    • Dart plugin version 181.4892.1

[✓] Connected device (1 available)
    • iPhone XS • B74C2265-233F-4EAB-89B5-6850589648EF • ios • iOS 12.1 (simulator)

! Doctor found issues in 2 categories.

[miguelcmedeiros]

I'm closing this ticket since I found that the onTapCancel event is triggered in this situation. So, not a problem of the framework, but from the developer :)

[github-actions]

This thread has been automatically locked since there has not been any recent activity after it was closed. If you are still experiencing a similar issue, please open a new bug, including the output of flutter doctor -v and a minimal reproduction of the issue.