HtmlElementView does not display video from webcam after popping the dialog and returning back to access web cam

main.dart

import 'dart:async';
import 'dart:typed_data';

import 'package:flutter/material.dart';
import 'package:flutter/services.dart';
import 'dart:html' as html;
import 'dart:ui' as ui;

void main() {
  runApp(MyApp());
}

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
      title: 'Flutter Demo',
      theme: ThemeData(
        primarySwatch: Colors.blue,
      ),
      home: MyHomePage(title: 'Flutter Demo Home Page'),
    );
  }
}

class MyHomePage extends StatefulWidget {
  MyHomePage({Key key, this.title}) : super(key: key);

  final String title;

  @override
  _MyHomePageState createState() => _MyHomePageState();
}

class _MyHomePageState extends State<MyHomePage> {
  Uint8List byteArray;

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      appBar: AppBar(
        title: Text(widget.title),
      ),
      body: Center(
        child: Container(
          child: byteArray != null ? Image.memory(byteArray) : null,
        ),
      ),
      floatingActionButton: FloatingActionButton(
        onPressed: () async {
          byteArray = await showDialog<Uint8List>(
              context: context,
              builder: (BuildContext context) {
                return FractionallySizedBox(
                  heightFactor: 0.5,
                  widthFactor: 0.5,
                  child: WebCam(),
                );
              });

          setState(() {});
        },
//         tooltip: 'Increment',
        child: Icon(Icons.add),
      ),
    );
  }
}

class WebCam extends StatefulWidget {
  @override
  _WebCamState createState() => _WebCamState();
}

class _WebCamState extends State<WebCam> {
  html.VideoElement _webcamVideoElement;

  @override
  void initState() {
    super.initState();

    // Create a video element which will be provided with stream source
    _webcamVideoElement = new html.VideoElement();
    // Register a webcam
    // ignore: undefined_prefixed_name
    ui.platformViewRegistry.registerViewFactory(
        'webcamVideoElement', (int viewId) => _webcamVideoElement);

    // Access the webcam stream
    getMedia();
  }

  getMedia() async {
    html.window.navigator.getUserMedia(video: true).then((streamHandle) async {
      _webcamVideoElement.srcObject = streamHandle;
      await _webcamVideoElement.play();
    }).catchError((onError) {
      print(onError);
    });
  }

  @override
  void dispose() {
    if (_webcamVideoElement.srcObject != null &&
        _webcamVideoElement.srcObject.active) {
      _webcamVideoElement.pause();
      var tracks = _webcamVideoElement.srcObject.getTracks();
      _webcamVideoElement.srcObject = null;

      tracks.forEach((track) {
        track.stop();
      });
    }
    super.dispose();
  }

  @override
  Widget build(BuildContext context) {
    return Scaffold(
      body: Stack(
        children: [
          Container(
            child: new HtmlElementView(
              key: UniqueKey(),
              viewType: 'webcamVideoElement',
            ),
          ),
          // RaisedButton(
          //   child: Text('Play/Pause'),
          //   onPressed: () async {
          //     if (_webcamVideoElement.paused) {
          //       await getMedia();
          //     } else {
          //       print(_webcamVideoElement.srcObject.active);
          //       _webcamVideoElement.pause();
          //       var tracks = _webcamVideoElement.srcObject.getTracks();

          //       _webcamVideoElement.srcObject = null;

          //       tracks.forEach((track) {
          //         track.stop();
          //       });
          //     }
          //   },
          // ),
          Align(
            alignment: Alignment.topRight,
            child: RaisedButton(
              child: Text('Capture'),
              onPressed: () async {
                _webcamVideoElement.pause();
                //drawing canvas and converting to blob
                html.CanvasElement canvas = new html.CanvasElement(
                    width: _webcamVideoElement.videoWidth,
                    height: _webcamVideoElement.videoHeight);
                html.CanvasRenderingContext2D ctx = canvas.context2D;
                ctx.drawImage(_webcamVideoElement, 0, 0);
                final blob = await canvas.toBlob('image/jpeg', 0.8);

                final completer = Completer<Uint8List>();
                final reader = html.FileReader();
                reader.readAsArrayBuffer(blob);
                reader.onLoad.listen((_) => completer.complete(reader.result));
                Uint8List byteArray = await completer.future;

                //stopping tracks
                var tracks = _webcamVideoElement.srcObject.getTracks();
                _webcamVideoElement.srcObject = null;
                tracks.forEach((track) {
                  track.stop();
                });

                Navigator.pop(context, byteArray);
              },
            ),
          ),
        ],
      ),
    );
  }
}