implement mobile scanner method channel

-import 'package:flutter/foundation.dart';
+import 'dart:async';
+
 import 'package:flutter/services.dart';
 import 'package:flutter/services.dart';
+import 'package:flutter/widgets.dart';
+import 'package:mobile_scanner/src/enums/camera_facing.dart';
+import 'package:mobile_scanner/src/enums/torch_state.dart';
 import 'package:mobile_scanner/src/mobile_scanner_platform_interface.dart';
 import 'package:mobile_scanner/src/mobile_scanner_platform_interface.dart';
 
 
 /// An implementation of [MobileScannerPlatform] that uses method channels.
 /// An implementation of [MobileScannerPlatform] that uses method channels.
 class MethodChannelMobileScanner extends MobileScannerPlatform {
 class MethodChannelMobileScanner extends MobileScannerPlatform {
   /// The method channel used to interact with the native platform.
   /// The method channel used to interact with the native platform.
   @visibleForTesting
   @visibleForTesting
-  final methodChannel = const MethodChannel('dev.steenbakker.mobile_scanner/scanner/method');
+  final methodChannel = const MethodChannel(
+    'dev.steenbakker.mobile_scanner/scanner/method',
+  );
 
 
   /// The event channel that sends back scanned barcode events.
   /// The event channel that sends back scanned barcode events.
   @visibleForTesting
   @visibleForTesting
-  final eventChannel = const EventChannel('dev.steenbakker.mobile_scanner/scanner/event');
+  final eventChannel = const EventChannel(
+    'dev.steenbakker.mobile_scanner/scanner/event',
+  );
+
+  Stream<Map<Object?, Object?>>? _eventsStream;
+
+  Stream<Map<Object?, Object?>> get eventsStream {
+    _eventsStream ??=
+        eventChannel.receiveBroadcastStream().cast<Map<Object?, Object?>>();
+
+    return _eventsStream!;
+  }
+
+  int? _textureId;
+
+  @override
+  Stream<TorchState> get torchStateStream {
+    return eventsStream
+        .where((event) => event['name'] == 'torchState')
+        .map((event) => TorchState.fromRawValue(event['data'] as int? ?? 0));
+  }
+
+  @override
+  Stream<double> get zoomScaleStateStream {
+    return eventsStream
+        .where((event) => event['name'] == 'zoomScaleState')
+        .map((event) => event['data'] as double? ?? 0.0);
+  }
+
+  @override
+  Future<bool> analyzeImage(String path) async {
+    final bool? result = await methodChannel.invokeMethod<bool>(
+      'analyzeImage',
+      path,
+    );
+
+    return result ?? false;
+  }
+
+  @override
+  Widget buildCameraView() => Texture(textureId: _textureId!);
+
+  @override
+  Future<void> resetZoomScale() async {
+    await methodChannel.invokeMethod<void>('resetScale');
+  }
+
+  @override
+  Future<void> setTorchState(TorchState torchState) async {
+    await methodChannel.invokeMethod<void>('torch', torchState.rawValue);
+  }
+
+  @override
+  Future<void> setZoomScale(double zoomScale) async {
+    await methodChannel.invokeMethod<void>('setScale', zoomScale);
+  }
+
+  @override
+  Future<void> start(CameraFacing cameraDirection) {}
+
+  @override
+  Future<void> stop() async {
+    await methodChannel.invokeMethod<void>('stop');
+  }
+
+  @override
+  Future<void> updateScanWindow(Rect? window) async {
+    await methodChannel.invokeMethod<void>(
+      'updateScanWindow',
+      {'rect': window},
+    );
+  }
+
+  @override
+  Future<void> dispose() async {
+    await stop();
+  }
 }
 }