packages/camera/camera_windows/lib/camera_windows.dart - mirrors/packages - Git at Google

 // Copyright 2013 The Flutter Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.

 import 'dart:async';
 import 'dart:math';

 import 'package:camera_platform_interface/camera_platform_interface.dart';
 import 'package:flutter/services.dart';
 import 'package:flutter/widgets.dart';
 import 'package:stream_transform/stream_transform.dart';

 /// An implementation of [CameraPlatform] for Windows.
 class CameraWindows extends CameraPlatform {
   /// Registers the Windows implementation of CameraPlatform.
   static void registerWith() {
     CameraPlatform.instance = CameraWindows();
   }

   /// The method channel used to interact with the native platform.
   @visibleForTesting
   final MethodChannel pluginChannel =
       const MethodChannel('plugins.flutter.io/camera_windows');

   /// Camera specific method channels to allow communicating with specific cameras.
   final Map<int, MethodChannel> _cameraChannels = <int, MethodChannel>{};

   /// The controller that broadcasts events coming from handleCameraMethodCall
   ///
   /// It is a `broadcast` because multiple controllers will connect to
   /// different stream views of this Controller.
   /// This is only exposed for test purposes. It shouldn't be used by clients of
   /// the plugin as it may break or change at any time.
   @visibleForTesting
   final StreamController<CameraEvent> cameraEventStreamController =
       StreamController<CameraEvent>.broadcast();

   /// Returns a stream of camera events for the given [cameraId].
   Stream<CameraEvent> _cameraEvents(int cameraId) =>
       cameraEventStreamController.stream
           .where((CameraEvent event) => event.cameraId == cameraId);

   @override
   Future<List<CameraDescription>> availableCameras() async {
     try {
       final List<Map<dynamic, dynamic>>? cameras = await pluginChannel
           .invokeListMethod<Map<dynamic, dynamic>>('availableCameras');

       if (cameras == null) {
         return <CameraDescription>[];
       }

       return cameras.map((Map<dynamic, dynamic> camera) {
         return CameraDescription(
           name: camera['name'] as String,
           lensDirection:
               parseCameraLensDirection(camera['lensFacing'] as String),
           sensorOrientation: camera['sensorOrientation'] as int,
         );
       }).toList();
     } on PlatformException catch (e) {
       throw CameraException(e.code, e.message);
     }
   }

   @override
   Future<int> createCamera(
     CameraDescription cameraDescription,
     ResolutionPreset? resolutionPreset, {
     bool enableAudio = false,
   }) async {
     try {
       // If resolutionPreset is not specified, plugin selects the highest resolution possible.
       final Map<String, dynamic>? reply = await pluginChannel
           .invokeMapMethod<String, dynamic>('create', <String, dynamic>{
         'cameraName': cameraDescription.name,
         'resolutionPreset': _serializeResolutionPreset(resolutionPreset),
         'enableAudio': enableAudio,
       });

       if (reply == null) {
         throw CameraException('System', 'Cannot create camera');
       }

       return reply['cameraId']! as int;
     } on PlatformException catch (e) {
       throw CameraException(e.code, e.message);
     }
   }

   @override
   Future<void> initializeCamera(
     int cameraId, {
     ImageFormatGroup imageFormatGroup = ImageFormatGroup.unknown,
   }) async {
     final int requestedCameraId = cameraId;

     /// Creates channel for camera events.
     _cameraChannels.putIfAbsent(requestedCameraId, () {
       final MethodChannel channel = MethodChannel(
           'plugins.flutter.io/camera_windows/camera$requestedCameraId');
       channel.setMethodCallHandler(
         (MethodCall call) => handleCameraMethodCall(call, requestedCameraId),
       );
       return channel;
     });

     final Map<String, double>? reply;
     try {
       reply = await pluginChannel.invokeMapMethod<String, double>(
         'initialize',
         <String, dynamic>{
           'cameraId': requestedCameraId,
         },
       );
     } on PlatformException catch (e) {
       throw CameraException(e.code, e.message);
     }

     cameraEventStreamController.add(
       CameraInitializedEvent(
         requestedCameraId,
         reply!['previewWidth']!,
         reply['previewHeight']!,
         ExposureMode.auto,
         false,
         FocusMode.auto,
         false,
       ),
     );
   }

   @override
   Future<void> dispose(int cameraId) async {
     await pluginChannel.invokeMethod<void>(
       'dispose',
       <String, dynamic>{'cameraId': cameraId},
     );

     // Destroy method channel after camera is disposed to be able to handle last messages.
     if (_cameraChannels.containsKey(cameraId)) {
       final MethodChannel? cameraChannel = _cameraChannels[cameraId];
       cameraChannel?.setMethodCallHandler(null);
       _cameraChannels.remove(cameraId);
     }
   }

   @override
   Stream<CameraInitializedEvent> onCameraInitialized(int cameraId) {
     return _cameraEvents(cameraId).whereType<CameraInitializedEvent>();
   }

   @override
   Stream<CameraResolutionChangedEvent> onCameraResolutionChanged(int cameraId) {
     /// Windows API does not automatically change the camera's resolution
     /// during capture so these events are never send from the platform.
     /// Support for changing resolution should be implemented, if support for
     /// requesting resolution change is added to camera platform interface.
     return const Stream<CameraResolutionChangedEvent>.empty();
   }

   @override
   Stream<CameraClosingEvent> onCameraClosing(int cameraId) {
     return _cameraEvents(cameraId).whereType<CameraClosingEvent>();
   }

   @override
   Stream<CameraErrorEvent> onCameraError(int cameraId) {
     return _cameraEvents(cameraId).whereType<CameraErrorEvent>();
   }

   @override
   Stream<VideoRecordedEvent> onVideoRecordedEvent(int cameraId) {
     return _cameraEvents(cameraId).whereType<VideoRecordedEvent>();
   }

   @override
   Stream<DeviceOrientationChangedEvent> onDeviceOrientationChanged() {
     // TODO(jokerttu): Implement device orientation detection, https://github.com/flutter/flutter/issues/97540.
     // Force device orientation to landscape as by default camera plugin uses portraitUp orientation.
     return Stream<DeviceOrientationChangedEvent>.value(
       const DeviceOrientationChangedEvent(DeviceOrientation.landscapeRight),
     );
   }

   @override
   Future<void> lockCaptureOrientation(
     int cameraId,
     DeviceOrientation orientation,
   ) async {
     // TODO(jokerttu): Implement lock capture orientation feature, https://github.com/flutter/flutter/issues/97540.
     throw UnimplementedError('lockCaptureOrientation() is not implemented.');
   }

   @override
   Future<void> unlockCaptureOrientation(int cameraId) async {
     // TODO(jokerttu): Implement unlock capture orientation feature, https://github.com/flutter/flutter/issues/97540.
     throw UnimplementedError('unlockCaptureOrientation() is not implemented.');
   }

   @override
   Future<XFile> takePicture(int cameraId) async {
     final String? path;
     path = await pluginChannel.invokeMethod<String>(
       'takePicture',
       <String, dynamic>{'cameraId': cameraId},
     );

     return XFile(path!);
   }

   @override
   Future<void> prepareForVideoRecording() =>
       pluginChannel.invokeMethod<void>('prepareForVideoRecording');

   @override
   Future<void> startVideoRecording(int cameraId,
       {Duration? maxVideoDuration}) async {
     return startVideoCapturing(
         VideoCaptureOptions(cameraId, maxDuration: maxVideoDuration));
   }

   @override
   Future<void> startVideoCapturing(VideoCaptureOptions options) async {
     if (options.streamCallback != null || options.streamOptions != null) {
       throw UnimplementedError(
           'Streaming is not currently supported on Windows');
     }

     await pluginChannel.invokeMethod<void>(
       'startVideoRecording',
       <String, dynamic>{
         'cameraId': options.cameraId,
         'maxVideoDuration': options.maxDuration?.inMilliseconds,
       },
     );
   }

   @override
   Future<XFile> stopVideoRecording(int cameraId) async {
     final String? path;

     path = await pluginChannel.invokeMethod<String>(
       'stopVideoRecording',
       <String, dynamic>{'cameraId': cameraId},
     );

     return XFile(path!);
   }

   @override
   Future<void> pauseVideoRecording(int cameraId) async {
     throw UnsupportedError(
         'pauseVideoRecording() is not supported due to Win32 API limitations.');
   }

   @override
   Future<void> resumeVideoRecording(int cameraId) async {
     throw UnsupportedError(
         'resumeVideoRecording() is not supported due to Win32 API limitations.');
   }

   @override
   Future<void> setFlashMode(int cameraId, FlashMode mode) async {
     // TODO(jokerttu): Implement flash mode support, https://github.com/flutter/flutter/issues/97537.
     throw UnimplementedError('setFlashMode() is not implemented.');
   }

   @override
   Future<void> setExposureMode(int cameraId, ExposureMode mode) async {
     // TODO(jokerttu): Implement explosure mode support, https://github.com/flutter/flutter/issues/97537.
     throw UnimplementedError('setExposureMode() is not implemented.');
   }

   @override
   Future<void> setExposurePoint(int cameraId, Point<double>? point) async {
     assert(point == null || point.x >= 0 && point.x <= 1);
     assert(point == null || point.y >= 0 && point.y <= 1);

     throw UnsupportedError(
         'setExposurePoint() is not supported due to Win32 API limitations.');
   }

   @override
   Future<double> getMinExposureOffset(int cameraId) async {
     // TODO(jokerttu): Implement exposure control support, https://github.com/flutter/flutter/issues/97537.
     // Value is returned to support existing implementations.
     return 0.0;
   }

   @override
   Future<double> getMaxExposureOffset(int cameraId) async {
     // TODO(jokerttu): Implement exposure control support, https://github.com/flutter/flutter/issues/97537.
     // Value is returned to support existing implementations.
     return 0.0;
   }

   @override
   Future<double> getExposureOffsetStepSize(int cameraId) async {
     // TODO(jokerttu): Implement exposure control support, https://github.com/flutter/flutter/issues/97537.
     // Value is returned to support existing implementations.
     return 1.0;
   }

   @override
   Future<double> setExposureOffset(int cameraId, double offset) async {
     // TODO(jokerttu): Implement exposure control support, https://github.com/flutter/flutter/issues/97537.
     throw UnimplementedError('setExposureOffset() is not implemented.');
   }

   @override
   Future<void> setFocusMode(int cameraId, FocusMode mode) async {
     // TODO(jokerttu): Implement focus mode support, https://github.com/flutter/flutter/issues/97537.
     throw UnimplementedError('setFocusMode() is not implemented.');
   }

   @override
   Future<void> setFocusPoint(int cameraId, Point<double>? point) async {
     assert(point == null || point.x >= 0 && point.x <= 1);
     assert(point == null || point.y >= 0 && point.y <= 1);

     throw UnsupportedError(
         'setFocusPoint() is not supported due to Win32 API limitations.');
   }

   @override
   Future<double> getMinZoomLevel(int cameraId) async {
     // TODO(jokerttu): Implement zoom level support, https://github.com/flutter/flutter/issues/97537.
     // Value is returned to support existing implementations.
     return 1.0;
   }

   @override
   Future<double> getMaxZoomLevel(int cameraId) async {
     // TODO(jokerttu): Implement zoom level support, https://github.com/flutter/flutter/issues/97537.
     // Value is returned to support existing implementations.
     return 1.0;
   }

   @override
   Future<void> setZoomLevel(int cameraId, double zoom) async {
     // TODO(jokerttu): Implement zoom level support, https://github.com/flutter/flutter/issues/97537.
     throw UnimplementedError('setZoomLevel() is not implemented.');
   }

   @override
   Future<void> pausePreview(int cameraId) async {
     await pluginChannel.invokeMethod<double>(
       'pausePreview',
       <String, dynamic>{'cameraId': cameraId},
     );
   }

   @override
   Future<void> resumePreview(int cameraId) async {
     await pluginChannel.invokeMethod<double>(
       'resumePreview',
       <String, dynamic>{'cameraId': cameraId},
     );
   }

   @override
   Widget buildPreview(int cameraId) {
     return Texture(textureId: cameraId);
   }

   /// Returns the resolution preset as a nullable String.
   String? _serializeResolutionPreset(ResolutionPreset? resolutionPreset) {
     switch (resolutionPreset) {
       case null:
         return null;
       case ResolutionPreset.max:
         return 'max';
       case ResolutionPreset.ultraHigh:
         return 'ultraHigh';
       case ResolutionPreset.veryHigh:
         return 'veryHigh';
       case ResolutionPreset.high:
         return 'high';
       case ResolutionPreset.medium:
         return 'medium';
       case ResolutionPreset.low:
         return 'low';
     }
   }

   /// Converts messages received from the native platform into camera events.
   ///
   /// This is only exposed for test purposes. It shouldn't be used by clients
   /// of the plugin as it may break or change at any time.
   @visibleForTesting
   Future<dynamic> handleCameraMethodCall(MethodCall call, int cameraId) async {
     switch (call.method) {
       case 'camera_closing':
         cameraEventStreamController.add(
           CameraClosingEvent(
             cameraId,
           ),
         );
         break;
       case 'video_recorded':
         final Map<String, Object?> arguments =
             (call.arguments as Map<Object?, Object?>).cast<String, Object?>();
         final int? maxDuration = arguments['maxVideoDuration'] as int?;
         // This is called if maxVideoDuration was given on record start.
         cameraEventStreamController.add(
           VideoRecordedEvent(
             cameraId,
             XFile(arguments['path']! as String),
             maxDuration != null ? Duration(milliseconds: maxDuration) : null,
           ),
         );
         break;
       case 'error':
         final Map<String, Object?> arguments =
             (call.arguments as Map<Object?, Object?>).cast<String, Object?>();
         cameraEventStreamController.add(
           CameraErrorEvent(
             cameraId,
             arguments['description']! as String,
           ),
         );
         break;
       default:
         throw UnimplementedError();
     }
   }

   /// Parses string presentation of the camera lens direction and returns enum value.
   @visibleForTesting
   CameraLensDirection parseCameraLensDirection(String string) {
     switch (string) {
       case 'front':
         return CameraLensDirection.front;
       case 'back':
         return CameraLensDirection.back;
       case 'external':
         return CameraLensDirection.external;
     }
     throw ArgumentError('Unknown CameraLensDirection value');
   }
 }
	// Copyright 2013 The Flutter Authors. All rights reserved.
	// Use of this source code is governed by a BSD-style license that can be
	// found in the LICENSE file.

	import 'dart:async';
	import 'dart:math';

	import 'package:camera_platform_interface/camera_platform_interface.dart';
	import 'package:flutter/services.dart';
	import 'package:flutter/widgets.dart';
	import 'package:stream_transform/stream_transform.dart';

	/// An implementation of [CameraPlatform] for Windows.
	class CameraWindows extends CameraPlatform {
	/// Registers the Windows implementation of CameraPlatform.
	static void registerWith() {
	CameraPlatform.instance = CameraWindows();
	}

	/// The method channel used to interact with the native platform.
	@visibleForTesting
	final MethodChannel pluginChannel =
	const MethodChannel('plugins.flutter.io/camera_windows');

	/// Camera specific method channels to allow communicating with specific cameras.
	final Map<int, MethodChannel> _cameraChannels = <int, MethodChannel>{};

	/// The controller that broadcasts events coming from handleCameraMethodCall
	///
	/// It is a `broadcast` because multiple controllers will connect to
	/// different stream views of this Controller.
	/// This is only exposed for test purposes. It shouldn't be used by clients of
	/// the plugin as it may break or change at any time.
	@visibleForTesting
	final StreamController<CameraEvent> cameraEventStreamController =
	StreamController<CameraEvent>.broadcast();

	/// Returns a stream of camera events for the given [cameraId].
	Stream<CameraEvent> _cameraEvents(int cameraId) =>
	cameraEventStreamController.stream
	.where((CameraEvent event) => event.cameraId == cameraId);

	@override
	Future<List<CameraDescription>> availableCameras() async {
	try {
	final List<Map<dynamic, dynamic>>? cameras = await pluginChannel
	.invokeListMethod<Map<dynamic, dynamic>>('availableCameras');

	if (cameras == null) {
	return <CameraDescription>[];
	}

	return cameras.map((Map<dynamic, dynamic> camera) {
	return CameraDescription(
	name: camera['name'] as String,
	lensDirection:
	parseCameraLensDirection(camera['lensFacing'] as String),
	sensorOrientation: camera['sensorOrientation'] as int,
	);
	}).toList();
	} on PlatformException catch (e) {
	throw CameraException(e.code, e.message);
	}
	}

	@override
	Future<int> createCamera(
	CameraDescription cameraDescription,
	ResolutionPreset? resolutionPreset, {
	bool enableAudio = false,
	}) async {
	try {
	// If resolutionPreset is not specified, plugin selects the highest resolution possible.
	final Map<String, dynamic>? reply = await pluginChannel
	.invokeMapMethod<String, dynamic>('create', <String, dynamic>{
	'cameraName': cameraDescription.name,
	'resolutionPreset': _serializeResolutionPreset(resolutionPreset),
	'enableAudio': enableAudio,
	});

	if (reply == null) {
	throw CameraException('System', 'Cannot create camera');
	}

	return reply['cameraId']! as int;
	} on PlatformException catch (e) {
	throw CameraException(e.code, e.message);
	}
	}

	@override
	Future<void> initializeCamera(
	int cameraId, {
	ImageFormatGroup imageFormatGroup = ImageFormatGroup.unknown,
	}) async {
	final int requestedCameraId = cameraId;

	/// Creates channel for camera events.
	_cameraChannels.putIfAbsent(requestedCameraId, () {
	final MethodChannel channel = MethodChannel(
	'plugins.flutter.io/camera_windows/camera$requestedCameraId');
	channel.setMethodCallHandler(
	(MethodCall call) => handleCameraMethodCall(call, requestedCameraId),
	);
	return channel;
	});

	final Map<String, double>? reply;
	try {
	reply = await pluginChannel.invokeMapMethod<String, double>(
	'initialize',
	<String, dynamic>{
	'cameraId': requestedCameraId,
	},
	);
	} on PlatformException catch (e) {
	throw CameraException(e.code, e.message);
	}

	cameraEventStreamController.add(
	CameraInitializedEvent(
	requestedCameraId,
	reply!['previewWidth']!,
	reply['previewHeight']!,
	ExposureMode.auto,
	false,
	FocusMode.auto,
	false,
	),
	);
	}

	@override
	Future<void> dispose(int cameraId) async {
	await pluginChannel.invokeMethod<void>(
	'dispose',
	<String, dynamic>{'cameraId': cameraId},
	);

	// Destroy method channel after camera is disposed to be able to handle last messages.
	if (_cameraChannels.containsKey(cameraId)) {
	final MethodChannel? cameraChannel = _cameraChannels[cameraId];
	cameraChannel?.setMethodCallHandler(null);
	_cameraChannels.remove(cameraId);
	}
	}

	@override
	Stream<CameraInitializedEvent> onCameraInitialized(int cameraId) {
	return _cameraEvents(cameraId).whereType<CameraInitializedEvent>();
	}

	@override
	Stream<CameraResolutionChangedEvent> onCameraResolutionChanged(int cameraId) {
	/// Windows API does not automatically change the camera's resolution
	/// during capture so these events are never send from the platform.
	/// Support for changing resolution should be implemented, if support for
	/// requesting resolution change is added to camera platform interface.
	return const Stream<CameraResolutionChangedEvent>.empty();
	}

	@override
	Stream<CameraClosingEvent> onCameraClosing(int cameraId) {
	return _cameraEvents(cameraId).whereType<CameraClosingEvent>();
	}

	@override
	Stream<CameraErrorEvent> onCameraError(int cameraId) {
	return _cameraEvents(cameraId).whereType<CameraErrorEvent>();
	}

	@override
	Stream<VideoRecordedEvent> onVideoRecordedEvent(int cameraId) {
	return _cameraEvents(cameraId).whereType<VideoRecordedEvent>();
	}

	@override
	Stream<DeviceOrientationChangedEvent> onDeviceOrientationChanged() {
	// TODO(jokerttu): Implement device orientation detection, https://github.com/flutter/flutter/issues/97540.
	// Force device orientation to landscape as by default camera plugin uses portraitUp orientation.
	return Stream<DeviceOrientationChangedEvent>.value(
	const DeviceOrientationChangedEvent(DeviceOrientation.landscapeRight),
	);
	}

	@override
	Future<void> lockCaptureOrientation(
	int cameraId,
	DeviceOrientation orientation,
	) async {
	// TODO(jokerttu): Implement lock capture orientation feature, https://github.com/flutter/flutter/issues/97540.
	throw UnimplementedError('lockCaptureOrientation() is not implemented.');
	}

	@override
	Future<void> unlockCaptureOrientation(int cameraId) async {
	// TODO(jokerttu): Implement unlock capture orientation feature, https://github.com/flutter/flutter/issues/97540.
	throw UnimplementedError('unlockCaptureOrientation() is not implemented.');
	}

	@override
	Future<XFile> takePicture(int cameraId) async {
	final String? path;
	path = await pluginChannel.invokeMethod<String>(
	'takePicture',
	<String, dynamic>{'cameraId': cameraId},
	);

	return XFile(path!);
	}

	@override
	Future<void> prepareForVideoRecording() =>
	pluginChannel.invokeMethod<void>('prepareForVideoRecording');

	@override
	Future<void> startVideoRecording(int cameraId,
	{Duration? maxVideoDuration}) async {
	return startVideoCapturing(
	VideoCaptureOptions(cameraId, maxDuration: maxVideoDuration));
	}

	@override
	Future<void> startVideoCapturing(VideoCaptureOptions options) async {
	if (options.streamCallback != null \|\| options.streamOptions != null) {
	throw UnimplementedError(
	'Streaming is not currently supported on Windows');
	}

	await pluginChannel.invokeMethod<void>(
	'startVideoRecording',
	<String, dynamic>{
	'cameraId': options.cameraId,
	'maxVideoDuration': options.maxDuration?.inMilliseconds,
	},
	);
	}

	@override
	Future<XFile> stopVideoRecording(int cameraId) async {
	final String? path;

	path = await pluginChannel.invokeMethod<String>(
	'stopVideoRecording',
	<String, dynamic>{'cameraId': cameraId},
	);

	return XFile(path!);
	}

	@override
	Future<void> pauseVideoRecording(int cameraId) async {
	throw UnsupportedError(
	'pauseVideoRecording() is not supported due to Win32 API limitations.');
	}

	@override
	Future<void> resumeVideoRecording(int cameraId) async {
	throw UnsupportedError(
	'resumeVideoRecording() is not supported due to Win32 API limitations.');
	}

	@override
	Future<void> setFlashMode(int cameraId, FlashMode mode) async {
	// TODO(jokerttu): Implement flash mode support, https://github.com/flutter/flutter/issues/97537.
	throw UnimplementedError('setFlashMode() is not implemented.');
	}

	@override
	Future<void> setExposureMode(int cameraId, ExposureMode mode) async {
	// TODO(jokerttu): Implement explosure mode support, https://github.com/flutter/flutter/issues/97537.
	throw UnimplementedError('setExposureMode() is not implemented.');
	}

	@override
	Future<void> setExposurePoint(int cameraId, Point<double>? point) async {
	assert(point == null \|\| point.x >= 0 && point.x <= 1);
	assert(point == null \|\| point.y >= 0 && point.y <= 1);

	throw UnsupportedError(
	'setExposurePoint() is not supported due to Win32 API limitations.');
	}

	@override
	Future<double> getMinExposureOffset(int cameraId) async {
	// TODO(jokerttu): Implement exposure control support, https://github.com/flutter/flutter/issues/97537.
	// Value is returned to support existing implementations.
	return 0.0;
	}

	@override
	Future<double> getMaxExposureOffset(int cameraId) async {
	// TODO(jokerttu): Implement exposure control support, https://github.com/flutter/flutter/issues/97537.
	// Value is returned to support existing implementations.
	return 0.0;
	}

	@override
	Future<double> getExposureOffsetStepSize(int cameraId) async {
	// TODO(jokerttu): Implement exposure control support, https://github.com/flutter/flutter/issues/97537.
	// Value is returned to support existing implementations.
	return 1.0;
	}

	@override
	Future<double> setExposureOffset(int cameraId, double offset) async {
	// TODO(jokerttu): Implement exposure control support, https://github.com/flutter/flutter/issues/97537.
	throw UnimplementedError('setExposureOffset() is not implemented.');
	}

	@override
	Future<void> setFocusMode(int cameraId, FocusMode mode) async {
	// TODO(jokerttu): Implement focus mode support, https://github.com/flutter/flutter/issues/97537.
	throw UnimplementedError('setFocusMode() is not implemented.');
	}

	@override
	Future<void> setFocusPoint(int cameraId, Point<double>? point) async {
	assert(point == null \|\| point.x >= 0 && point.x <= 1);
	assert(point == null \|\| point.y >= 0 && point.y <= 1);

	throw UnsupportedError(
	'setFocusPoint() is not supported due to Win32 API limitations.');
	}

	@override
	Future<double> getMinZoomLevel(int cameraId) async {
	// TODO(jokerttu): Implement zoom level support, https://github.com/flutter/flutter/issues/97537.
	// Value is returned to support existing implementations.
	return 1.0;
	}

	@override
	Future<double> getMaxZoomLevel(int cameraId) async {
	// TODO(jokerttu): Implement zoom level support, https://github.com/flutter/flutter/issues/97537.
	// Value is returned to support existing implementations.
	return 1.0;
	}

	@override
	Future<void> setZoomLevel(int cameraId, double zoom) async {
	// TODO(jokerttu): Implement zoom level support, https://github.com/flutter/flutter/issues/97537.
	throw UnimplementedError('setZoomLevel() is not implemented.');
	}

	@override
	Future<void> pausePreview(int cameraId) async {
	await pluginChannel.invokeMethod<double>(
	'pausePreview',
	<String, dynamic>{'cameraId': cameraId},
	);
	}

	@override
	Future<void> resumePreview(int cameraId) async {
	await pluginChannel.invokeMethod<double>(
	'resumePreview',
	<String, dynamic>{'cameraId': cameraId},
	);
	}

	@override
	Widget buildPreview(int cameraId) {
	return Texture(textureId: cameraId);
	}

	/// Returns the resolution preset as a nullable String.
	String? _serializeResolutionPreset(ResolutionPreset? resolutionPreset) {
	switch (resolutionPreset) {
	case null:
	return null;
	case ResolutionPreset.max:
	return 'max';
	case ResolutionPreset.ultraHigh:
	return 'ultraHigh';
	case ResolutionPreset.veryHigh:
	return 'veryHigh';
	case ResolutionPreset.high:
	return 'high';
	case ResolutionPreset.medium:
	return 'medium';
	case ResolutionPreset.low:
	return 'low';
	}
	}

	/// Converts messages received from the native platform into camera events.
	///
	/// This is only exposed for test purposes. It shouldn't be used by clients
	/// of the plugin as it may break or change at any time.
	@visibleForTesting
	Future<dynamic> handleCameraMethodCall(MethodCall call, int cameraId) async {
	switch (call.method) {
	case 'camera_closing':
	cameraEventStreamController.add(
	CameraClosingEvent(
	cameraId,
	),
	);
	break;
	case 'video_recorded':
	final Map<String, Object?> arguments =
	(call.arguments as Map<Object?, Object?>).cast<String, Object?>();
	final int? maxDuration = arguments['maxVideoDuration'] as int?;
	// This is called if maxVideoDuration was given on record start.
	cameraEventStreamController.add(
	VideoRecordedEvent(
	cameraId,
	XFile(arguments['path']! as String),
	maxDuration != null ? Duration(milliseconds: maxDuration) : null,
	),
	);
	break;
	case 'error':
	final Map<String, Object?> arguments =
	(call.arguments as Map<Object?, Object?>).cast<String, Object?>();
	cameraEventStreamController.add(
	CameraErrorEvent(
	cameraId,
	arguments['description']! as String,
	),
	);
	break;
	default:
	throw UnimplementedError();
	}
	}

	/// Parses string presentation of the camera lens direction and returns enum value.
	@visibleForTesting
	CameraLensDirection parseCameraLensDirection(String string) {
	switch (string) {
	case 'front':
	return CameraLensDirection.front;
	case 'back':
	return CameraLensDirection.back;
	case 'external':
	return CameraLensDirection.external;
	}
	throw ArgumentError('Unknown CameraLensDirection value');
	}
	}