implemented MockCameraContainerBloc to stub camera on simulator

.vscode/launch.json

@@ -82,5 +82,20 @@
             ],
             "program": "${workspaceFolder}/lib/main_dev.dart",
         },
+        {
+            "name": "dev-simulator",
+            "request": "launch",
+            "type": "dart",
+            "flutterMode": "debug",
+            "args": [
+                "--flavor",
+                "dev",
+                "--dart-define",
+                "cameraPreviewAspectRatio=240/320",
+                "--dart-define",
+                "cameraStubImage=assets/camera_stub_image.jpg"
+            ],
+            "program": "${workspaceFolder}/lib/main_dev.dart",
+        },
     ],
 }

lib/application.dart

@@ -3,6 +3,7 @@ import 'package:flutter/services.dart';
 import 'package:flutter_localizations/flutter_localizations.dart';
 import 'package:lightmeter/data/models/supported_locale.dart';
 import 'package:lightmeter/generated/l10n.dart';
+import 'package:lightmeter/platform_config.dart';
 import 'package:lightmeter/providers/user_preferences_provider.dart';
 import 'package:lightmeter/screens/metering/flow_metering.dart';
 import 'package:lightmeter/screens/settings/flow_settings.dart';
@@ -17,13 +18,13 @@ class Application extends StatelessWidget {
     return AnnotatedRegion(
       value: SystemUiOverlayStyle(
         statusBarColor: Colors.transparent,
-        statusBarBrightness:
-            systemIconsBrightness == Brightness.light ? Brightness.dark : Brightness.light,
+        statusBarBrightness: systemIconsBrightness == Brightness.light ? Brightness.dark : Brightness.light,
         statusBarIconBrightness: systemIconsBrightness,
         systemNavigationBarColor: Colors.transparent,
         systemNavigationBarIconBrightness: systemIconsBrightness,
       ),
       child: MaterialApp(
+        debugShowCheckedModeBanner: !PlatformConfig.isTest,
         theme: theme,
         locale: Locale(UserPreferencesProvider.localeOf(context).intlName),
         localizationsDelegates: const [

lib/platform_config.dart

@@ -7,4 +7,6 @@ class PlatformConfig {
   }
 
   static String get cameraStubImage => const String.fromEnvironment('cameraStubImage');
+
+  static bool get isTest => cameraStubImage.isNotEmpty;
 }

lib/screens/metering/components/camera_container/bloc_container_camera.dart

@@ -4,7 +4,6 @@ import 'dart:io';
 import 'dart:math' as math;
 
 import 'package:camera/camera.dart';
-import 'package:exif/exif.dart';
 import 'package:flutter/material.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
@@ -17,7 +16,9 @@ import 'package:lightmeter/screens/metering/components/camera_container/event_co
 import 'package:lightmeter/screens/metering/components/camera_container/models/camera_error_type.dart';
 import 'package:lightmeter/screens/metering/components/camera_container/state_container_camera.dart';
 import 'package:lightmeter/screens/metering/components/shared/ev_source_base/bloc_base_ev_source.dart';
-import 'package:m3_lightmeter_resources/m3_lightmeter_resources.dart';
+import 'package:lightmeter/utils/ev_from_bytes.dart';
+
+part 'mock_bloc_container_camera.dart';
 
 class CameraContainerBloc extends EvSourceBlocBase<CameraContainerEvent, CameraContainerState> {
   final MeteringInteractor _meteringInteractor;
@@ -213,33 +214,15 @@ class CameraContainerBloc extends EvSourceBlocBase<CameraContainerEvent, CameraC
   Future<double?> _takePhoto() async {
     try {
       // https://github.com/flutter/flutter/issues/84957#issuecomment-1661155095
-
-      late final Uint8List bytes;
-      if (PlatformConfig.cameraStubImage.isNotEmpty) {
-        bytes = (await rootBundle.load(PlatformConfig.cameraStubImage)).buffer.asUint8List();
-      } else {
       await _cameraController!.setFocusMode(FocusMode.locked);
       await _cameraController!.setExposureMode(ExposureMode.locked);
       final file = await _cameraController!.takePicture();
       await _cameraController!.setFocusMode(FocusMode.auto);
       await _cameraController!.setExposureMode(ExposureMode.auto);
-        bytes = await file.readAsBytes();
+      final bytes = await file.readAsBytes();
       Directory(file.path).deleteSync(recursive: true);
-      }
 
-      final tags = await readExifFromBytes(bytes);
-      final iso = double.tryParse("${tags["EXIF ISOSpeedRatings"]}");
-      final apertureValueRatio = (tags["EXIF FNumber"]?.values as IfdRatios?)?.ratios.first;
-      final speedValueRatio = (tags["EXIF ExposureTime"]?.values as IfdRatios?)?.ratios.first;
-      if (iso == null || apertureValueRatio == null || speedValueRatio == null) {
-        log('Error parsing EXIF: ${tags.keys}');
-        return null;
-      }
-
-      final aperture = apertureValueRatio.numerator / apertureValueRatio.denominator;
-      final speed = speedValueRatio.numerator / speedValueRatio.denominator;
-
-      return log2(math.pow(aperture, 2)) - log2(speed) - log2(iso / 100);
+      return await evFromImage(bytes);
     } catch (e) {
       log(e.toString());
       return null;

lib/screens/metering/components/camera_container/mock_bloc_container_camera.dart

@@ -0,0 +1,80 @@
+part of 'bloc_container_camera.dart';
+
+class MockCameraContainerBloc extends CameraContainerBloc {
+  MockCameraContainerBloc(
+    super._meteringInteractor,
+    super.communicationBloc,
+  );
+
+  @override
+  Future<void> _onRequestPermission(_, Emitter emit) async {
+    add(const InitializeEvent());
+  }
+
+  @override
+  Future<void> _onOpenAppSettings(_, Emitter emit) async {
+    _meteringInteractor.openAppSettings();
+  }
+
+  @override
+  Future<void> _onInitialize(_, Emitter emit) async {
+    emit(const CameraLoadingState());
+    try {
+      _cameraController = CameraController(
+        const CameraDescription(name: '0', lensDirection: CameraLensDirection.back, sensorOrientation: 0),
+        ResolutionPreset.low,
+        enableAudio: false,
+      );
+
+      _zoomRange = const RangeValues(1, 6);
+      _currentZoom = _zoomRange!.start;
+
+      _exposureOffsetRange = const RangeValues(-4, 4);
+      _exposureStep = 0.1;
+      _currentExposureOffset = 0.0;
+
+      emit(CameraInitializedState(_cameraController!));
+
+      _emitActiveState(emit);
+    } catch (e) {
+      emit(const CameraErrorState(CameraErrorType.other));
+    }
+  }
+
+  @override
+  Future<void> _onZoomChanged(ZoomChangedEvent event, Emitter emit) async {
+    if (event.value >= _zoomRange!.start && event.value <= _zoomRange!.end) {
+      _currentZoom = event.value;
+      _emitActiveState(emit);
+    }
+  }
+
+  @override
+  Future<void> _onExposureOffsetChanged(ExposureOffsetChangedEvent event, Emitter emit) async {
+    _currentExposureOffset = event.value;
+    _emitActiveState(emit);
+  }
+
+  @override
+  Future<void> _onExposureOffsetResetEvent(ExposureOffsetResetEvent event, Emitter emit) async {
+    _meteringInteractor.quickVibration();
+    add(const ExposureOffsetChangedEvent(0));
+  }
+
+  @override
+  Future<void> _onExposureSpotChangedEvent(ExposureSpotChangedEvent event, Emitter emit) async {}
+
+  @override
+  bool get _canTakePhoto => PlatformConfig.cameraStubImage.isNotEmpty;
+
+  @override
+  Future<double?> _takePhoto() async {
+    try {
+      final bytes = (await rootBundle.load(PlatformConfig.cameraStubImage)).buffer.asUint8List();
+      return await evFromImage(bytes);
+    } catch (e) {
+      log(e.toString());
+      return null;
+    }
+  }
+}

lib/screens/metering/components/camera_container/provider_container_camera.dart

@@ -1,6 +1,7 @@
 import 'package:flutter/material.dart';
 import 'package:flutter_bloc/flutter_bloc.dart';
 import 'package:lightmeter/data/models/exposure_pair.dart';
+import 'package:lightmeter/platform_config.dart';
 import 'package:lightmeter/screens/metering/communication/bloc_communication_metering.dart';
 import 'package:lightmeter/screens/metering/components/camera_container/bloc_container_camera.dart';
 import 'package:lightmeter/screens/metering/components/camera_container/event_container_camera.dart';
@@ -30,12 +31,18 @@ class CameraContainerProvider extends StatelessWidget {
 
   @override
   Widget build(BuildContext context) {
-    return BlocProvider(
+    return BlocProvider<CameraContainerBloc>(
       lazy: false,
-      create: (context) => CameraContainerBloc(
+      create: (context) => (PlatformConfig.cameraStubImage.isNotEmpty
+          ? MockCameraContainerBloc(
               MeteringInteractorProvider.of(context),
               context.read<MeteringCommunicationBloc>(),
-      )..add(const RequestPermissionEvent()),
+            )
+          : CameraContainerBloc(
+              MeteringInteractorProvider.of(context),
+              context.read<MeteringCommunicationBloc>(),
+            ))
+        ..add(const RequestPermissionEvent()),
       child: CameraContainer(
         fastest: fastest,
         slowest: slowest,

lib/utils/ev_from_bytes.dart

@@ -0,0 +1,27 @@
+import 'dart:developer';
+import 'dart:math' as math;
+import 'dart:typed_data';
+
+import 'package:exif/exif.dart';
+import 'package:m3_lightmeter_resources/m3_lightmeter_resources.dart';
+
+Future<double?> evFromImage(Uint8List bytes) async {
+  try {
+    final tags = await readExifFromBytes(bytes);
+    final iso = double.tryParse("${tags["EXIF ISOSpeedRatings"]}");
+    final apertureValueRatio = (tags["EXIF FNumber"]?.values as IfdRatios?)?.ratios.first;
+    final speedValueRatio = (tags["EXIF ExposureTime"]?.values as IfdRatios?)?.ratios.first;
+    if (iso == null || apertureValueRatio == null || speedValueRatio == null) {
+      log('Error parsing EXIF: ${tags.keys}');
+      return null;
+    }
+
+    final aperture = apertureValueRatio.numerator / apertureValueRatio.denominator;
+    final speed = speedValueRatio.numerator / speedValueRatio.denominator;
+
+    return log2(math.pow(aperture, 2)) - log2(speed) - log2(iso / 100);
+  } catch (e) {
+    log(e.toString());
+    return null;
+  }
+}