show multiple times will cause exception

[dujianchi]

First, sorry for my English...
There are three exception:
1.quick click button twice, then click navigator bar back icon, it will not pop at first time ,need click back twice.
2.click 'toast' button once, when flushbar dismissing, click 'toast' again, it doesn't show.
3.click 'toast' and wait a second, before it dismiss, click 'toast' again, then wait, about one second after, it whill cause a exception.
Then, here is my code:

import 'package:flutter/material.dart';
import 'package:flushbar/flushbar.dart';

void main() => runApp(MaterialApp(
      home: MyApp(),
      routes: <String, WidgetBuilder>{
        '/two': (context) => TwoButton(),
      },
    ));

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) => Scaffold(
        appBar: AppBar(
          title: Text('test'),
        ),
        body: Center(
          child: RaisedButton(
            child: Text('go'),
            onPressed: () {
              Navigator.pushNamed(context, '/two');
            },
          ),
        ),
      );
}

class TwoButton extends StatefulWidget {
  @override
  State<StatefulWidget> createState() => _TwoButtonState();
}

class _TwoButtonState extends State<TwoButton> {
  @override
  Widget build(BuildContext context) => Scaffold(
        appBar: AppBar(
          title: Text('twp'),
        ),
        body: ListView(
          children: <Widget>[
            RaisedButton(
              child: Text('toast'),
              onPressed: () {
                Flushbar(
                  message: 'toast',
                  duration: const Duration(seconds: 2),
                  isDismissible: true,
                ).show(context);
              },
            ),
            Text("""

    1.quick click button twice, then click navigator bar back icon, it will not pop at first time ,need click back twice.

    2.click 'toast' button once, when flushbar dismissing, click 'toast' again, it doesn't show.

    3.click 'toast' and wait a second, before it dismiss, click 'toast' again, then wait, about one second after, it whill cause a exception:
        E/flutter (31575): [ERROR:flutter/shell/common/shell.cc(181)] Dart Error: Unhandled exception:
        E/flutter (31575): NoSuchMethodError: The method 'stop' was called on null.
        E/flutter (31575): Receiver: null
        E/flutter (31575): Tried calling: stop(canceled: true)
        E/flutter (31575): #0      Object.noSuchMethod (dart:core/runtime/libobject_patch.dart:48:5)
        E/flutter (31575): #1      AnimationController.stop (package:flutter/src/animation/animation_controller.dart:556:13)
        E/flutter (31575): #2      AnimationController._animateToInternal (package:flutter/src/animation/animation_controller.dart:433:5)
        E/flutter (31575): #3      AnimationController.reverse (package:flutter/src/animation/animation_controller.dart:381:12)
        E/flutter (31575): #4      _FlushbarState._configureTimer.<anonymous closure> (package:flushbar/flushbar.dart:252:24)
        E/flutter (31575): #5      Timer._createTimer.<anonymous closure> (dart:async/runtime/libtimer_patch.dart:21:15)

            """),
          ],
        ),
      );
}

and my flutter doctor:

Doctor summary (to see all details, run flutter doctor -v):
[√] Flutter (Channel beta, v0.7.3, on Microsoft Windows [Version 10.0.17134.228], locale zh-CN)
[√] Android toolchain - develop for Android devices (Android SDK 28.0.2)
[√] Android Studio (version 3.1)
[!] IntelliJ IDEA Ultimate Edition (version 2018.2)
    X Flutter plugin not installed; this adds Flutter specific functionality.
    X Dart plugin not installed; this adds Dart specific functionality.
[√] Connected devices (1 available)

! Doctor found issues in 1 category.

flushbar: ^0.8.3

[dujianchi]

my device:
Xiaomi Redmi 4X
MIUI 10 8.8.30 beta
Android 7.1.2
RAM 2GB
CPU Octa-core Max 1.4GHz
Kernel version 3.18.31-perf-g52975e0
Available storage 1.44GB
Total storeage 16GB

[AndreHaueisen]

Hi @dujianchi
I'm aware of this problem. It happens when you have more than one Flushbar showing, and you dismiss them without dismissing the top one first. I'm trying hard to fix it, but I do not have the solution yet.

I will probably have to animate the route itself instead of animating the widget when Flushbar.show(context) is called. I will notify you when it is ready.

[dujianchi]

Thank you very much.

[dujianchi]

I may be fix those bug... It took me a whole day. https://github.com/dujianchi/flushbar . I don't push a pr because I afraid I was wrong.
I use PopupRoute replace OverlayRoute, so it can only show once...

[AndreHaueisen]

@dujianchi
Version 0.9 is out. See if it provides a more reliable Flushbar and fixes this problem. Make sure you read the Changelog