RiveRenderObject._toArtboard throws error

[kaptnkoala]

Description

We see many errors in our crash reporting tools, that RiveRenderObject._toArtboard is throwing an error, when it tries to handle a pointer event and is not anymore attached to the render tree. We can not reproduce the error in a local debug build, but this has become the biggest cluster of errors for our release apps. I have attached the full stack trace in the additional context section.

Probably the issues would be relatively easy to solve, when the handleEvent method would also check, if the RenderObject is still attached before handling the received event like this:

  @override
  void handleEvent(PointerEvent event, HitTestEntry entry) {
    assert(debugHandleEvent(event, entry));
    if (!enableHitTests || !attached) {
      return;
    }    
  }

Expected behavior

The code should contain a safeguard condition, that prevents that events are tried to be handle on an unattached instance of the RiveRenderObject.

Device & Versions (please complete the following information)

• Device: Mostly iOS devices
• Flutter Version:

Flutter 3.13.8 • channel stable • https://github.com/flutter/flutter.git
Framework • revision 6c4930c4ac (6 weeks ago) • 2023-10-18 10:57:55 -0500
Engine • revision 767d8c75e8
Tools • Dart 3.1.4 • DevTools 2.25.0

Additional context

_TypeError: Null check operator used on a null value
  File "object.dart", line 3255, in RenderObject.getTransformTo
  File "box.dart", line 2612, in RenderBox.localToGlobal
  File "rive.dart", line 141, in RiveRenderObject._toArtboard
  File "rive.dart", line 148, in RiveRenderObject._hitHelper
  File "rive.dart", line 177, in RiveRenderObject.handleEvent
  File "binding.dart", line 468, in GestureBinding.dispatchEvent
  File "binding.dart", line 333, in RendererBinding.dispatchEvent
  File "binding.dart", line 413, in GestureBinding._handlePointerEventImmediately
  File "binding.dart", line 376, in GestureBinding.handlePointerEvent
  File "binding.dart", line 323, in GestureBinding._flushPointerEventQueue
  File "binding.dart", line 292, in GestureBinding._handlePointerDataPacket
  File "hooks.dart", line 186, in _invoke1
  File "platform_dispatcher.dart", line 424, in PlatformDispatcher._dispatchPointerDataPacket
  File "hooks.dart", line 119, in _dispatchPointerDataPacket

[HayesGordon]

Hi @kaptnkoala, we'll get this added in the next release. Thanks for reporting and suggesting a fix