packages/camera/camera_web/lib/src/camera_service.dart - mirrors/plugins - 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:html' as html;
 import 'dart:ui';

 import 'package:camera_platform_interface/camera_platform_interface.dart';
 import 'package:camera_web/src/camera.dart';
 import 'package:camera_web/src/shims/dart_js_util.dart';
 import 'package:camera_web/src/types/types.dart';
 import 'package:flutter/foundation.dart';
 import 'package:flutter/services.dart';

 /// A service to fetch, map camera settings and
 /// obtain the camera stream.
 class CameraService {
   // A facing mode constraint name.
   static const _facingModeKey = "facingMode";

   /// The current browser window used to access media devices.
   @visibleForTesting
   html.Window? window = html.window;

   /// The utility to manipulate JavaScript interop objects.
   @visibleForTesting
   JsUtil jsUtil = JsUtil();

   /// Returns a media stream associated with the camera device
   /// with [cameraId] and constrained by [options].
   Future<html.MediaStream> getMediaStreamForOptions(
     CameraOptions options, {
     int cameraId = 0,
   }) async {
     final mediaDevices = window?.navigator.mediaDevices;

     // Throw a not supported exception if the current browser window
     // does not support any media devices.
     if (mediaDevices == null) {
       throw PlatformException(
         code: CameraErrorCode.notSupported.toString(),
         message: 'The camera is not supported on this device.',
       );
     }

     try {
       final constraints = await options.toJson();
       return await mediaDevices.getUserMedia(constraints);
     } on html.DomException catch (e) {
       switch (e.name) {
         case 'NotFoundError':
         case 'DevicesNotFoundError':
           throw CameraWebException(
             cameraId,
             CameraErrorCode.notFound,
             'No camera found for the given camera options.',
           );
         case 'NotReadableError':
         case 'TrackStartError':
           throw CameraWebException(
             cameraId,
             CameraErrorCode.notReadable,
             'The camera is not readable due to a hardware error '
             'that prevented access to the device.',
           );
         case 'OverconstrainedError':
         case 'ConstraintNotSatisfiedError':
           throw CameraWebException(
             cameraId,
             CameraErrorCode.overconstrained,
             'The camera options are impossible to satisfy.',
           );
         case 'NotAllowedError':
         case 'PermissionDeniedError':
           throw CameraWebException(
             cameraId,
             CameraErrorCode.permissionDenied,
             'The camera cannot be used or the permission '
             'to access the camera is not granted.',
           );
         case 'TypeError':
           throw CameraWebException(
             cameraId,
             CameraErrorCode.type,
             'The camera options are incorrect or attempted'
             'to access the media input from an insecure context.',
           );
         case 'AbortError':
           throw CameraWebException(
             cameraId,
             CameraErrorCode.abort,
             'Some problem occurred that prevented the camera from being used.',
           );
         case 'SecurityError':
           throw CameraWebException(
             cameraId,
             CameraErrorCode.security,
             'The user media support is disabled in the current browser.',
           );
         default:
           throw CameraWebException(
             cameraId,
             CameraErrorCode.unknown,
             'An unknown error occured when fetching the camera stream.',
           );
       }
     } catch (_) {
       throw CameraWebException(
         cameraId,
         CameraErrorCode.unknown,
         'An unknown error occured when fetching the camera stream.',
       );
     }
   }

   /// Returns the zoom level capability for the given [camera].
   ///
   /// Throws a [CameraWebException] if the zoom level is not supported
   /// or the camera has not been initialized or started.
   ZoomLevelCapability getZoomLevelCapabilityForCamera(
     Camera camera,
   ) {
     final mediaDevices = window?.navigator.mediaDevices;
     final supportedConstraints = mediaDevices?.getSupportedConstraints();
     final zoomLevelSupported =
         supportedConstraints?[ZoomLevelCapability.constraintName] ?? false;

     if (!zoomLevelSupported) {
       throw CameraWebException(
         camera.textureId,
         CameraErrorCode.zoomLevelNotSupported,
         'The zoom level is not supported in the current browser.',
       );
     }

     final videoTracks = camera.stream?.getVideoTracks() ?? [];

     if (videoTracks.isNotEmpty) {
       final defaultVideoTrack = videoTracks.first;

       /// The zoom level capability is represented by MediaSettingsRange.
       /// See: https://developer.mozilla.org/en-US/docs/Web/API/MediaSettingsRange
       final zoomLevelCapability = defaultVideoTrack
               .getCapabilities()[ZoomLevelCapability.constraintName] ??
           {};

       // The zoom level capability is a nested JS object, therefore
       // we need to access its properties with the js_util library.
       // See: https://api.dart.dev/stable/2.13.4/dart-js_util/getProperty.html
       final minimumZoomLevel = jsUtil.getProperty(zoomLevelCapability, 'min');
       final maximumZoomLevel = jsUtil.getProperty(zoomLevelCapability, 'max');

       if (minimumZoomLevel != null && maximumZoomLevel != null) {
         return ZoomLevelCapability(
           minimum: minimumZoomLevel.toDouble(),
           maximum: maximumZoomLevel.toDouble(),
           videoTrack: defaultVideoTrack,
         );
       } else {
         throw CameraWebException(
           camera.textureId,
           CameraErrorCode.zoomLevelNotSupported,
           'The zoom level is not supported by the current camera.',
         );
       }
     } else {
       throw CameraWebException(
         camera.textureId,
         CameraErrorCode.notStarted,
         'The camera has not been initialized or started.',
       );
     }
   }

   /// Returns a facing mode of the [videoTrack]
   /// (null if the facing mode is not available).
   String? getFacingModeForVideoTrack(html.MediaStreamTrack videoTrack) {
     final mediaDevices = window?.navigator.mediaDevices;

     // Throw a not supported exception if the current browser window
     // does not support any media devices.
     if (mediaDevices == null) {
       throw PlatformException(
         code: CameraErrorCode.notSupported.toString(),
         message: 'The camera is not supported on this device.',
       );
     }

     // Check if the camera facing mode is supported by the current browser.
     final supportedConstraints = mediaDevices.getSupportedConstraints();
     final facingModeSupported = supportedConstraints[_facingModeKey] ?? false;

     // Return null if the facing mode is not supported.
     if (!facingModeSupported) {
       return null;
     }

     // Extract the facing mode from the video track settings.
     // The property may not be available if it's not supported
     // by the browser or not available due to context.
     //
     // MediaTrackSettings:
     // https://developer.mozilla.org/en-US/docs/Web/API/MediaTrackSettings
     final videoTrackSettings = videoTrack.getSettings();
     final facingMode = videoTrackSettings[_facingModeKey];

     if (facingMode == null) {
       // If the facing mode does not exist in the video track settings,
       // check for the facing mode in the video track capabilities.
       //
       // MediaTrackCapabilities:
       // https://www.w3.org/TR/mediacapture-streams/#dom-mediatrackcapabilities

       // Check if getting the video track capabilities is supported.
       //
       // The method may not be supported on Firefox.
       // See: https://developer.mozilla.org/en-US/docs/Web/API/MediaStreamTrack/getCapabilities#browser_compatibility
       if (!jsUtil.hasProperty(videoTrack, 'getCapabilities')) {
         // Return null if the video track capabilites are not supported.
         return null;
       }

       final videoTrackCapabilities = videoTrack.getCapabilities();

       // A list of facing mode capabilities as
       // the camera may support multiple facing modes.
       final facingModeCapabilities =
           List<String>.from(videoTrackCapabilities[_facingModeKey] ?? []);

       if (facingModeCapabilities.isNotEmpty) {
         final facingModeCapability = facingModeCapabilities.first;
         return facingModeCapability;
       } else {
         // Return null if there are no facing mode capabilities.
         return null;
       }
     }

     return facingMode;
   }

   /// Maps the given [facingMode] to [CameraLensDirection].
   ///
   /// The following values for the facing mode are supported:
   /// https://developer.mozilla.org/en-US/docs/Web/API/MediaTrackSettings/facingMode
   CameraLensDirection mapFacingModeToLensDirection(String facingMode) {
     switch (facingMode) {
       case 'user':
         return CameraLensDirection.front;
       case 'environment':
         return CameraLensDirection.back;
       case 'left':
       case 'right':
       default:
         return CameraLensDirection.external;
     }
   }

   /// Maps the given [facingMode] to [CameraType].
   ///
   /// See [CameraMetadata.facingMode] for more details.
   CameraType mapFacingModeToCameraType(String facingMode) {
     switch (facingMode) {
       case 'user':
         return CameraType.user;
       case 'environment':
         return CameraType.environment;
       case 'left':
       case 'right':
       default:
         return CameraType.user;
     }
   }

   /// Maps the given [resolutionPreset] to [Size].
   Size mapResolutionPresetToSize(ResolutionPreset resolutionPreset) {
     switch (resolutionPreset) {
       case ResolutionPreset.max:
       case ResolutionPreset.ultraHigh:
         return Size(4096, 2160);
       case ResolutionPreset.veryHigh:
         return Size(1920, 1080);
       case ResolutionPreset.high:
         return Size(1280, 720);
       case ResolutionPreset.medium:
         return Size(720, 480);
       case ResolutionPreset.low:
       default:
         return Size(320, 240);
     }
   }

   /// Maps the given [deviceOrientation] to [OrientationType].
   String mapDeviceOrientationToOrientationType(
     DeviceOrientation deviceOrientation,
   ) {
     switch (deviceOrientation) {
       case DeviceOrientation.portraitUp:
         return OrientationType.portraitPrimary;
       case DeviceOrientation.landscapeLeft:
         return OrientationType.landscapePrimary;
       case DeviceOrientation.portraitDown:
         return OrientationType.portraitSecondary;
       case DeviceOrientation.landscapeRight:
         return OrientationType.landscapeSecondary;
     }
   }

   /// Maps the given [orientationType] to [DeviceOrientation].
   DeviceOrientation mapOrientationTypeToDeviceOrientation(
     String orientationType,
   ) {
     switch (orientationType) {
       case OrientationType.portraitPrimary:
         return DeviceOrientation.portraitUp;
       case OrientationType.landscapePrimary:
         return DeviceOrientation.landscapeLeft;
       case OrientationType.portraitSecondary:
         return DeviceOrientation.portraitDown;
       case OrientationType.landscapeSecondary:
         return DeviceOrientation.landscapeRight;
       default:
         return DeviceOrientation.portraitUp;
     }
   }
 }
	// 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:html' as html;
	import 'dart:ui';

	import 'package:camera_platform_interface/camera_platform_interface.dart';
	import 'package:camera_web/src/camera.dart';
	import 'package:camera_web/src/shims/dart_js_util.dart';
	import 'package:camera_web/src/types/types.dart';
	import 'package:flutter/foundation.dart';
	import 'package:flutter/services.dart';

	/// A service to fetch, map camera settings and
	/// obtain the camera stream.
	class CameraService {
	// A facing mode constraint name.
	static const _facingModeKey = "facingMode";

	/// The current browser window used to access media devices.
	@visibleForTesting
	html.Window? window = html.window;

	/// The utility to manipulate JavaScript interop objects.
	@visibleForTesting
	JsUtil jsUtil = JsUtil();

	/// Returns a media stream associated with the camera device
	/// with [cameraId] and constrained by [options].
	Future<html.MediaStream> getMediaStreamForOptions(
	CameraOptions options, {
	int cameraId = 0,
	}) async {
	final mediaDevices = window?.navigator.mediaDevices;

	// Throw a not supported exception if the current browser window
	// does not support any media devices.
	if (mediaDevices == null) {
	throw PlatformException(
	code: CameraErrorCode.notSupported.toString(),
	message: 'The camera is not supported on this device.',
	);
	}

	try {
	final constraints = await options.toJson();
	return await mediaDevices.getUserMedia(constraints);
	} on html.DomException catch (e) {
	switch (e.name) {
	case 'NotFoundError':
	case 'DevicesNotFoundError':
	throw CameraWebException(
	cameraId,
	CameraErrorCode.notFound,
	'No camera found for the given camera options.',
	);
	case 'NotReadableError':
	case 'TrackStartError':
	throw CameraWebException(
	cameraId,
	CameraErrorCode.notReadable,
	'The camera is not readable due to a hardware error '
	'that prevented access to the device.',
	);
	case 'OverconstrainedError':
	case 'ConstraintNotSatisfiedError':
	throw CameraWebException(
	cameraId,
	CameraErrorCode.overconstrained,
	'The camera options are impossible to satisfy.',
	);
	case 'NotAllowedError':
	case 'PermissionDeniedError':
	throw CameraWebException(
	cameraId,
	CameraErrorCode.permissionDenied,
	'The camera cannot be used or the permission '
	'to access the camera is not granted.',
	);
	case 'TypeError':
	throw CameraWebException(
	cameraId,
	CameraErrorCode.type,
	'The camera options are incorrect or attempted'
	'to access the media input from an insecure context.',
	);
	case 'AbortError':
	throw CameraWebException(
	cameraId,
	CameraErrorCode.abort,
	'Some problem occurred that prevented the camera from being used.',
	);
	case 'SecurityError':
	throw CameraWebException(
	cameraId,
	CameraErrorCode.security,
	'The user media support is disabled in the current browser.',
	);
	default:
	throw CameraWebException(
	cameraId,
	CameraErrorCode.unknown,
	'An unknown error occured when fetching the camera stream.',
	);
	}
	} catch (_) {
	throw CameraWebException(
	cameraId,
	CameraErrorCode.unknown,
	'An unknown error occured when fetching the camera stream.',
	);
	}
	}

	/// Returns the zoom level capability for the given [camera].
	///
	/// Throws a [CameraWebException] if the zoom level is not supported
	/// or the camera has not been initialized or started.
	ZoomLevelCapability getZoomLevelCapabilityForCamera(
	Camera camera,
	) {
	final mediaDevices = window?.navigator.mediaDevices;
	final supportedConstraints = mediaDevices?.getSupportedConstraints();
	final zoomLevelSupported =
	supportedConstraints?[ZoomLevelCapability.constraintName] ?? false;

	if (!zoomLevelSupported) {
	throw CameraWebException(
	camera.textureId,
	CameraErrorCode.zoomLevelNotSupported,
	'The zoom level is not supported in the current browser.',
	);
	}

	final videoTracks = camera.stream?.getVideoTracks() ?? [];

	if (videoTracks.isNotEmpty) {
	final defaultVideoTrack = videoTracks.first;

	/// The zoom level capability is represented by MediaSettingsRange.
	/// See: https://developer.mozilla.org/en-US/docs/Web/API/MediaSettingsRange
	final zoomLevelCapability = defaultVideoTrack
	.getCapabilities()[ZoomLevelCapability.constraintName] ??
	{};

	// The zoom level capability is a nested JS object, therefore
	// we need to access its properties with the js_util library.
	// See: https://api.dart.dev/stable/2.13.4/dart-js_util/getProperty.html
	final minimumZoomLevel = jsUtil.getProperty(zoomLevelCapability, 'min');
	final maximumZoomLevel = jsUtil.getProperty(zoomLevelCapability, 'max');

	if (minimumZoomLevel != null && maximumZoomLevel != null) {
	return ZoomLevelCapability(
	minimum: minimumZoomLevel.toDouble(),
	maximum: maximumZoomLevel.toDouble(),
	videoTrack: defaultVideoTrack,
	);
	} else {
	throw CameraWebException(
	camera.textureId,
	CameraErrorCode.zoomLevelNotSupported,
	'The zoom level is not supported by the current camera.',
	);
	}
	} else {
	throw CameraWebException(
	camera.textureId,
	CameraErrorCode.notStarted,
	'The camera has not been initialized or started.',
	);
	}
	}

	/// Returns a facing mode of the [videoTrack]
	/// (null if the facing mode is not available).
	String? getFacingModeForVideoTrack(html.MediaStreamTrack videoTrack) {
	final mediaDevices = window?.navigator.mediaDevices;

	// Throw a not supported exception if the current browser window
	// does not support any media devices.
	if (mediaDevices == null) {
	throw PlatformException(
	code: CameraErrorCode.notSupported.toString(),
	message: 'The camera is not supported on this device.',
	);
	}

	// Check if the camera facing mode is supported by the current browser.
	final supportedConstraints = mediaDevices.getSupportedConstraints();
	final facingModeSupported = supportedConstraints[_facingModeKey] ?? false;

	// Return null if the facing mode is not supported.
	if (!facingModeSupported) {
	return null;
	}

	// Extract the facing mode from the video track settings.
	// The property may not be available if it's not supported
	// by the browser or not available due to context.
	//
	// MediaTrackSettings:
	// https://developer.mozilla.org/en-US/docs/Web/API/MediaTrackSettings
	final videoTrackSettings = videoTrack.getSettings();
	final facingMode = videoTrackSettings[_facingModeKey];

	if (facingMode == null) {
	// If the facing mode does not exist in the video track settings,
	// check for the facing mode in the video track capabilities.
	//
	// MediaTrackCapabilities:
	// https://www.w3.org/TR/mediacapture-streams/#dom-mediatrackcapabilities

	// Check if getting the video track capabilities is supported.
	//
	// The method may not be supported on Firefox.
	// See: https://developer.mozilla.org/en-US/docs/Web/API/MediaStreamTrack/getCapabilities#browser_compatibility
	if (!jsUtil.hasProperty(videoTrack, 'getCapabilities')) {
	// Return null if the video track capabilites are not supported.
	return null;
	}

	final videoTrackCapabilities = videoTrack.getCapabilities();

	// A list of facing mode capabilities as
	// the camera may support multiple facing modes.
	final facingModeCapabilities =
	List<String>.from(videoTrackCapabilities[_facingModeKey] ?? []);

	if (facingModeCapabilities.isNotEmpty) {
	final facingModeCapability = facingModeCapabilities.first;
	return facingModeCapability;
	} else {
	// Return null if there are no facing mode capabilities.
	return null;
	}
	}

	return facingMode;
	}

	/// Maps the given [facingMode] to [CameraLensDirection].
	///
	/// The following values for the facing mode are supported:
	/// https://developer.mozilla.org/en-US/docs/Web/API/MediaTrackSettings/facingMode
	CameraLensDirection mapFacingModeToLensDirection(String facingMode) {
	switch (facingMode) {
	case 'user':
	return CameraLensDirection.front;
	case 'environment':
	return CameraLensDirection.back;
	case 'left':
	case 'right':
	default:
	return CameraLensDirection.external;
	}
	}

	/// Maps the given [facingMode] to [CameraType].
	///
	/// See [CameraMetadata.facingMode] for more details.
	CameraType mapFacingModeToCameraType(String facingMode) {
	switch (facingMode) {
	case 'user':
	return CameraType.user;
	case 'environment':
	return CameraType.environment;
	case 'left':
	case 'right':
	default:
	return CameraType.user;
	}
	}

	/// Maps the given [resolutionPreset] to [Size].
	Size mapResolutionPresetToSize(ResolutionPreset resolutionPreset) {
	switch (resolutionPreset) {
	case ResolutionPreset.max:
	case ResolutionPreset.ultraHigh:
	return Size(4096, 2160);
	case ResolutionPreset.veryHigh:
	return Size(1920, 1080);
	case ResolutionPreset.high:
	return Size(1280, 720);
	case ResolutionPreset.medium:
	return Size(720, 480);
	case ResolutionPreset.low:
	default:
	return Size(320, 240);
	}
	}

	/// Maps the given [deviceOrientation] to [OrientationType].
	String mapDeviceOrientationToOrientationType(
	DeviceOrientation deviceOrientation,
	) {
	switch (deviceOrientation) {
	case DeviceOrientation.portraitUp:
	return OrientationType.portraitPrimary;
	case DeviceOrientation.landscapeLeft:
	return OrientationType.landscapePrimary;
	case DeviceOrientation.portraitDown:
	return OrientationType.portraitSecondary;
	case DeviceOrientation.landscapeRight:
	return OrientationType.landscapeSecondary;
	}
	}

	/// Maps the given [orientationType] to [DeviceOrientation].
	DeviceOrientation mapOrientationTypeToDeviceOrientation(
	String orientationType,
	) {
	switch (orientationType) {
	case OrientationType.portraitPrimary:
	return DeviceOrientation.portraitUp;
	case OrientationType.landscapePrimary:
	return DeviceOrientation.landscapeLeft;
	case OrientationType.portraitSecondary:
	return DeviceOrientation.portraitDown;
	case OrientationType.landscapeSecondary:
	return DeviceOrientation.landscapeRight;
	default:
	return DeviceOrientation.portraitUp;
	}
	}
	}