Add platform interface versions of the image data classes

packages/camera/camera_platform_interface/lib/src/types/camera_image_data.dart

@@ -0,0 +1,119 @@
+// 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:typed_data';
+
+import 'package:flutter/foundation.dart';
+
+import '../../camera_platform_interface.dart';
+
+/// A single color plane of image data.
+///
+/// The number and meaning of the planes in an image are determined by its
+/// format.
+@immutable
+class CameraImagePlane {
+  /// Creates a new instance with the given bytes and optional metadata.
+  const CameraImagePlane({
+    required this.bytes,
+    required this.bytesPerRow,
+    this.bytesPerPixel,
+    this.height,
+    this.width,
+  });
+
+  /// Bytes representing this plane.
+  final Uint8List bytes;
+
+  /// The row stride for this color plane, in bytes.
+  final int bytesPerRow;
+
+  /// The distance between adjacent pixel samples in bytes, when available.
+  final int? bytesPerPixel;
+
+  /// Height of the pixel buffer, when available
+  final int? height;
+
+  /// Width of the pixel buffer, when available
+  final int? width;
+}
+
+/// Describes how pixels are represented in an image.
+@immutable
+class CameraImageFormat {
+  /// Create a new format with the given cross-platform group and raw underyling
+  /// platform identifier.
+  const CameraImageFormat(this.group, {required this.raw});
+
+  /// Describes the format group the raw image format falls into.
+  final ImageFormatGroup group;
+
+  /// Raw version of the format from the underlying platform.
+  ///
+  /// On Android, this should be an `int` from class
+  /// `android.graphics.ImageFormat`. See
+  /// https://developer.android.com/reference/android/graphics/ImageFormat
+  ///
+  /// On iOS, this should be a `FourCharCode` constant from Pixel Format
+  /// Identifiers. See
+  /// https://developer.apple.com/documentation/corevideo/1563591-pixel_format_identifiers
+  final dynamic raw;
+}
+
+/// A single complete image buffer from the platform camera.
+///
+/// This class allows for direct application access to the pixel data of an
+/// Image through one or more [Uint8List]. Each buffer is encapsulated in a
+/// [CameraImagePlane] that describes the layout of the pixel data in that
+/// plane. [CameraImageData] is not directly usable as a UI resource.
+///
+/// Although not all image formats are planar on all platforms, this class
+/// treats 1-dimensional images as single planar images.
+@immutable
+class CameraImageData {
+  /// Creates a new instance with the given format, planes, and metadata.
+  const CameraImageData({
+    required this.format,
+    required this.planes,
+    required this.height,
+    required this.width,
+    this.lensAperture,
+    this.sensorExposureTime,
+    this.sensorSensitivity,
+  });
+
+  /// Format of the image provided.
+  ///
+  /// Determines the number of planes needed to represent the image, and
+  /// the general layout of the pixel data in each [Uint8List].
+  final CameraImageFormat format;
+
+  /// Height of the image in pixels.
+  ///
+  /// For formats where some color channels are subsampled, this is the height
+  /// of the largest-resolution plane.
+  final int height;
+
+  /// Width of the image in pixels.
+  ///
+  /// For formats where some color channels are subsampled, this is the width
+  /// of the largest-resolution plane.
+  final int width;
+
+  /// The pixels planes for this image.
+  ///
+  /// The number of planes is determined by the format of the image.
+  final List<CameraImagePlane> planes;
+
+  /// The aperture settings for this image.
+  ///
+  /// Represented as an f-stop value.
+  final double? lensAperture;
+
+  /// The sensor exposure time for this image in nanoseconds.
+  final int? sensorExposureTime;
+
+  /// The sensor sensitivity in standard ISO arithmetic units.
+  final double? sensorSensitivity;
+}

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

@@ -4,6 +4,7 @@
 
 export 'camera_description.dart';
 export 'camera_exception.dart';
+export 'camera_image_data.dart';
 export 'exposure_mode.dart';
 export 'flash_mode.dart';
 export 'focus_mode.dart';

packages/camera/camera_platform_interface/test/types/camera_image_data_test.dart

@@ -0,0 +1,38 @@
+// 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:typed_data';
+
+import 'package:camera_platform_interface/camera_platform_interface.dart';
+import 'package:flutter/foundation.dart';
+import 'package:flutter_test/flutter_test.dart';
+
+void main() {
+  test('CameraImageData can be created', () {
+    debugDefaultTargetPlatformOverride = TargetPlatform.android;
+    final CameraImageData cameraImage = CameraImageData(
+      format: const CameraImageFormat(ImageFormatGroup.jpeg, raw: 42),
+      height: 100,
+      width: 200,
+      lensAperture: 1.8,
+      sensorExposureTime: 11,
+      sensorSensitivity: 92.0,
+      planes: <CameraImagePlane>[
+        CameraImagePlane(
+            bytes: Uint8List.fromList(<int>[1, 2, 3, 4]),
+            bytesPerRow: 4,
+            bytesPerPixel: 2,
+            height: 100,
+            width: 200)
+      ],
+    );
+    expect(cameraImage.format.group, ImageFormatGroup.jpeg);
+    expect(cameraImage.lensAperture, 1.8);
+    expect(cameraImage.sensorExposureTime, 11);
+    expect(cameraImage.sensorSensitivity, 92.0);
+    expect(cameraImage.height, 100);
+    expect(cameraImage.width, 200);
+    expect(cameraImage.planes.length, 1);
+  });
+}