[image_picker] getMedia platform changes (flutter#4174)

Adds `getMedia` and `getMultipleMedia` methods to  image_picker_platform_interface.

precursor to flutter/packages#3892

part of flutter#89159

Author: tarrinneal

packages/image_picker/image_picker_platform_interface/CHANGELOG.md

@@ -1,3 +1,7 @@
+## 2.8.0
+
+* Adds `getMedia` method.
+
 ## 2.7.0
 
 * Adds `CameraDelegatingImagePickerPlatform` as a base class for platform

packages/image_picker/image_picker_platform_interface/lib/src/method_channel/method_channel_image_picker.dart

@@ -252,6 +252,30 @@ class MethodChannelImagePicker extends ImagePickerPlatform {
     return paths.map((dynamic path) => XFile(path as String)).toList();
   }
 
+  @override
+  Future<List<XFile>> getMedia({
+    required MediaOptions options,
+  }) async {
+    final ImageOptions imageOptions = options.imageOptions;
+
+    final Map<String, dynamic> args = <String, dynamic>{
+      'maxImageWidth': imageOptions.maxWidth,
+      'maxImageHeight': imageOptions.maxHeight,
+      'imageQuality': imageOptions.imageQuality,
+      'allowMultiple': options.allowMultiple,
+    };
+
+    final List<XFile>? paths = await _channel
+        .invokeMethod<List<dynamic>?>(
+          'pickMedia',
+          args,
+        )
+        .then((List<dynamic>? paths) =>
+            paths?.map((dynamic path) => XFile(path as String)).toList());
+
+    return paths ?? <XFile>[];
+  }
+
   @override
   Future<XFile?> getVideo({
     required ImageSource source,
@@ -280,13 +304,21 @@ class MethodChannelImagePicker extends ImagePickerPlatform {
     assert(result.containsKey('path') != result.containsKey('errorCode'));
 
     final String? type = result['type'] as String?;
-    assert(type == kTypeImage || type == kTypeVideo);
+    assert(
+      type == kTypeImage || type == kTypeVideo || type == kTypeMedia,
+    );
 
     RetrieveType? retrieveType;
-    if (type == kTypeImage) {
-      retrieveType = RetrieveType.image;
-    } else if (type == kTypeVideo) {
-      retrieveType = RetrieveType.video;
+    switch (type) {
+      case kTypeImage:
+        retrieveType = RetrieveType.image;
+        break;
+      case kTypeVideo:
+        retrieveType = RetrieveType.video;
+        break;
+      case kTypeMedia:
+        retrieveType = RetrieveType.media;
+        break;
     }
 
     PlatformException? exception;

packages/image_picker/image_picker_platform_interface/lib/src/platform_interface/image_picker_platform.dart

@@ -213,6 +213,24 @@ abstract class ImagePickerPlatform extends PlatformInterface {
     throw UnimplementedError('getMultiImage() has not been implemented.');
   }
 
+  /// Returns a [List<XFile>] with the images and/or videos that were picked.
+  /// The images and videos come from the gallery.
+  ///
+  /// Where iOS supports HEIC images, Android 8 and below doesn't. Android 9 and
+  /// above only support HEIC images if used in addition to a size modification,
+  /// of which the usage is explained below.
+  ///
+  /// In Android, the MainActivity can be destroyed for various reasons.
+  /// If that happens, the result will be lost in this call. You can then
+  /// call [getLostData] when your app relaunches to retrieve the lost data.
+  ///
+  /// If no images or videos were picked, the return value is an empty list.
+  Future<List<XFile>> getMedia({
+    required MediaOptions options,
+  }) {
+    throw UnimplementedError('getMedia() has not been implemented.');
+  }
+
   /// Returns a [XFile] containing the video that was picked.
   ///
   /// The [source] argument controls where the video comes from. This can

packages/image_picker/image_picker_platform_interface/lib/src/types/image_options.dart

@@ -2,6 +2,40 @@
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
+import 'types.dart';
+
+/// Specifies options for picking a single image from the device's camera or gallery.
+///
+/// This class inheritance is a byproduct of the api changing over time.
+/// It exists solely to avoid breaking changes.
+class ImagePickerOptions extends ImageOptions {
+  /// Creates an instance with the given [maxHeight], [maxWidth], [imageQuality],
+  /// [referredCameraDevice] and [requestFullMetadata].
+  const ImagePickerOptions({
+    super.maxHeight,
+    super.maxWidth,
+    super.imageQuality,
+    super.requestFullMetadata,
+    this.preferredCameraDevice = CameraDevice.rear,
+  }) : super();
+
+  /// Creates an instance with the given [maxHeight], [maxWidth], [imageQuality],
+  /// [referredCameraDevice] and [requestFullMetadata].
+  ImagePickerOptions.createAndValidate({
+    super.maxHeight,
+    super.maxWidth,
+    super.imageQuality,
+    super.requestFullMetadata,
+    this.preferredCameraDevice = CameraDevice.rear,
+  }) : super.createAndValidate();
+
+  /// Used to specify the camera to use when the `source` is [ImageSource.camera].
+  ///
+  /// Ignored if the source is not [ImageSource.camera], or the chosen camera is not
+  /// supported on the device. Defaults to [CameraDevice.rear].
+  final CameraDevice preferredCameraDevice;
+}
+
 /// Specifies image-specific options for picking.
 class ImageOptions {
   /// Creates an instance with the given [maxHeight], [maxWidth], [imageQuality]
@@ -13,6 +47,18 @@ class ImageOptions {
     this.requestFullMetadata = true,
   });
 
+  /// Creates an instance with the given [maxHeight], [maxWidth], [imageQuality]
+  /// and [requestFullMetadata]. Throws if options are not valid.
+  ImageOptions.createAndValidate({
+    this.maxHeight,
+    this.maxWidth,
+    this.imageQuality,
+    this.requestFullMetadata = true,
+  }) {
+    _validateOptions(
+        maxWidth: maxWidth, maxHeight: maxHeight, imageQuality: imageQuality);
+  }
+
   /// The maximum width of the image, in pixels.
   ///
   /// If null, the image will only be resized if [maxHeight] is specified.
@@ -38,4 +84,19 @@ class ImageOptions {
   //
   // Defaults to true.
   final bool requestFullMetadata;
+
+  /// Validates that all values are within required ranges. Throws if not.
+  static void _validateOptions(
+      {double? maxWidth, final double? maxHeight, int? imageQuality}) {
+    if (imageQuality != null && (imageQuality < 0 || imageQuality > 100)) {
+      throw ArgumentError.value(
+          imageQuality, 'imageQuality', 'must be between 0 and 100');
+    }
+    if (maxWidth != null && maxWidth < 0) {
+      throw ArgumentError.value(maxWidth, 'maxWidth', 'cannot be negative');
+    }
+    if (maxHeight != null && maxHeight < 0) {
+      throw ArgumentError.value(maxHeight, 'maxHeight', 'cannot be negative');
+    }
+  }
 }

packages/image_picker/image_picker_platform_interface/lib/src/types/image_picker_options.dart

@@ -36,7 +36,8 @@ class LostDataResponse {
   /// An empty response should have [file], [exception] and [type] to be null.
   bool get isEmpty => _empty;
 
-  /// The file that was lost in a previous [getImage], [getMultiImage] or [getVideo] call due to MainActivity being destroyed.
+  /// The file that was lost in a previous [getImage], [getMultiImage],
+  /// [getVideo] or [getMedia] call due to MainActivity being destroyed.
   ///
   /// Can be null if [exception] exists.
   final XFile? file;
@@ -51,7 +52,7 @@ class LostDataResponse {
   /// Note that it is not the exception that caused the destruction of the MainActivity.
   final PlatformException? exception;
 
-  /// Can either be [RetrieveType.image] or [RetrieveType.video];
+  /// Can either be [RetrieveType.image], [RetrieveType.video], or [RetrieveType.media].
   ///
   /// If the lost data is empty, this will be null.
   final RetrieveType? type;

packages/image_picker/image_picker_platform_interface/lib/src/types/lost_data_response.dart

@@ -0,0 +1,23 @@
+// 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 'package:flutter/foundation.dart';
+
+import '../../image_picker_platform_interface.dart';
+
+/// Specifies options for selecting items when using [ImagePickerPlatform.getMedia].
+@immutable
+class MediaOptions {
+  /// Construct a new MediaOptions instance.
+  const MediaOptions({
+    this.imageOptions = const ImageOptions(),
+    required this.allowMultiple,
+  });
+
+  /// Options that will apply to images upon selection.
+  final ImageOptions imageOptions;
+
+  /// Whether to allow for selecting multiple media.
+  final bool allowMultiple;
+}

packages/image_picker/image_picker_platform_interface/lib/src/types/media_options.dart

@@ -0,0 +1,14 @@
+// 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 '../../image_picker_platform_interface.dart';
+
+/// The type of media to allow the user to select with [ImagePickerPlatform.getMedia].
+enum MediaSelectionType {
+  /// Static pictures.
+  image,
+
+  /// Videos.
+  video,
+}

packages/image_picker/image_picker_platform_interface/lib/src/types/media_selection_type.dart

@@ -8,5 +8,8 @@ enum RetrieveType {
   image,
 
   /// A video. See [ImagePicker.pickVideo].
-  video
+  video,
+
+  /// Either a video or a static picture. See [ImagePicker.pickMedia].
+  media,
 }

packages/image_picker/image_picker_platform_interface/lib/src/types/retrieve_type.dart

@@ -5,9 +5,10 @@
 export 'camera_delegate.dart';
 export 'camera_device.dart';
 export 'image_options.dart';
-export 'image_picker_options.dart';
 export 'image_source.dart';
 export 'lost_data_response.dart';
+export 'media_options.dart';
+export 'media_selection_type.dart';
 export 'multi_image_picker_options.dart';
 export 'picked_file/picked_file.dart';
 export 'retrieve_type.dart';
@@ -17,3 +18,6 @@ const String kTypeImage = 'image';
 
 /// Denotes that a video is being picked.
 const String kTypeVideo = 'video';
+
+/// Denotes that either a video or image is being picked.
+const String kTypeMedia = 'media';