feat: add cameras metadata

packages/camera/camera_web/lib/src/camera_web.dart

@@ -31,6 +31,10 @@ class CameraPlugin extends CameraPlatform {
 
   final CameraSettings _cameraSettings;
 
+  /// Metadata associated with each camera description.
+  /// Populated in [availableCameras].
+  final _camerasMetadata = <CameraDescription, CameraMetadata>{};
+
   /// The current browser window used to access media devices.
   @visibleForTesting
   html.Window? window = html.window;
@@ -57,7 +61,7 @@ class CameraPlugin extends CameraPlatform {
         .whereType<html.MediaDeviceInfo>()
         .where((device) => device.kind == MediaDeviceKind.videoInput)
 
-        /// The device id property is currently not supported on Internet Explorer.
+        /// The device id property is currently not supported on Internet Explorer:
         /// https://developer.mozilla.org/en-US/docs/Web/API/MediaDeviceInfo/deviceId#browser_compatibility
         .where((device) => device.deviceId != null);
 
@@ -97,7 +101,14 @@ class CameraPlugin extends CameraPlatform {
           sensorOrientation: 0,
         );
 
+        final cameraMetadata = CameraMetadata(
+          deviceId: videoInputDevice.deviceId!,
+          facingMode: facingMode,
+        );
+
         cameras.add(camera);
+
+        _camerasMetadata[camera] = cameraMetadata;
       } else {
         // Ignore as no video tracks exist in the current video input device.
         continue;

packages/camera/camera_web/lib/src/types/camera_metadata.dart

@@ -0,0 +1,19 @@
+/// Metadata used along the camera description
+/// to store additional web-specific camera details.
+class CameraMetadata {
+  /// Creates a new instance of [CameraMetadata]
+  /// with the given [deviceId] and [facingMode].
+  const CameraMetadata({required this.deviceId, required this.facingMode});
+
+  /// Uniquely identifies the camera device.
+  ///
+  /// See: https://developer.mozilla.org/en-US/docs/Web/API/MediaDeviceInfo/deviceId
+  final String deviceId;
+
+  /// Describes the direction the camera is facing towards.
+  /// May be `user`, `environment`, `left`, `right`
+  /// or null if the facing mode is not available.
+  ///
+  /// See: https://developer.mozilla.org/en-US/docs/Web/API/MediaTrackSettings/facingMode
+  final String? facingMode;
+}

packages/camera/camera_web/lib/src/types/types.dart

@@ -3,5 +3,6 @@
 // found in the LICENSE file.
 
 export 'camera_error_codes.dart';
+export 'camera_metadata.dart';
 export 'camera_options.dart';
 export 'media_device_kind.dart';