TransparentPointer fail

I'm trying to switch from using the flutter-mapbox-gl plugin to this one, and I ran into an issue...

I'm using a transparent pointer over the map, in a Stack widget, so I can turn off some automated panning and zooming if the user starts interacting with the map; I'm interpreting gestures as pans, zooms, and rotates, and also letting the gestures bubble through to the map. This works fine with that other mapbox plugin, but with this one I get:

I/flutter ( 8823): ⚠️ Unhandled Flutter error: 'package:flutter/src/gestures/tap.dart': Failed assertion: line 210 pos 14: '_down == null && _up == null': is not true.

======== Exception caught by gesture library =======================================================
The following assertion was thrown while dispatching a pointer event:
'package:flutter/src/gestures/tap.dart': Failed assertion: line 210 pos 14: '_down == null && _up == null': is not true.


Either the assertion indicates an error in the framework itself, or we should provide substantially more information in this error message to help you determine and fix the underlying cause.
In either case, please report this assertion by filing a bug on GitHub:
  https://github.com/flutter/flutter/issues/new?template=2_bug.md

When the exception was thrown, this was the stack: 
#2      BaseTapGestureRecognizer.addAllowedPointer (package:flutter/src/gestures/tap.dart:210:14)
#3      GestureRecognizer.addPointer (package:flutter/src/gestures/recognizer.dart:160:7)
#4      RawGestureDetectorState._handlePointerDown (package:flutter/src/widgets/gesture_detector.dart:1498:18)
#5      RenderPointerListener.handleEvent (package:flutter/src/rendering/proxy_box.dart:3168:29)
#6      GestureBinding.dispatchEvent (package:flutter/src/gestures/binding.dart:440:22)
#7      RendererBinding.dispatchEvent (package:flutter/src/rendering/binding.dart:336:11)
#8      GestureBinding._handlePointerEventImmediately (package:flutter/src/gestures/binding.dart:395:7)
#9      GestureBinding.handlePointerEvent (package:flutter/src/gestures/binding.dart:357:5)
#10     GestureBinding._flushPointerEventQueue (package:flutter/src/gestures/binding.dart:314:7)
#11     GestureBinding._handlePointerDataPacket (package:flutter/src/gestures/binding.dart:295:7)
#12     _invoke1 (dart:ui/hooks.dart:164:13)
#13     PlatformDispatcher._dispatchPointerDataPacket (dart:ui/platform_dispatcher.dart:361:7)
#14     _dispatchPointerDataPacket (dart:ui/hooks.dart:91:31)
(elided 2 frames from class _AssertionError)
Event: PointerDownEvent#85236(position: Offset(222.0, 753.2))
  position: Offset(222.0, 753.2)
Target: RenderPointerListener#00676 relayoutBoundary=up8
  parentData: <none> (can use size)
  constraints: BoxConstraints(0.0<=w<=411.4, 0.0<=h<=819.4)
  size: Size(411.4, 819.4)
  behavior: deferToChild
  listeners: down, panZoomStart

Is there a way to make this work?

Alternatively, is there a way to listen for user initiated zooms, pans, and rotates with this package?

首先，按照报告中所示的手势回调，在 Stack 中的 map 上使用 transparent_pointer 重现该 assertion。阅读 tap.dart、gesture_detector.dart 周围的 Flutter 手势栈，以及 map package 的手势入口点；当该交互不再触发 assertion，并且能够区分或记录用户发起的 pan、zoom 和 rotate 手势时，即视为完成。