[ios_platform_images] Add Swift Package Manager support (flutter#6684)

Adds Swift Package Manager support to `ios_platform_images`.

This does not migrate the example app's Xcode project; the example app's Xcode project is migrated whenever you run it using the Flutter tool with the Swift Package Manager feature enabled.

Fixes flutter#146909

Author: loic-sharma

packages/ios_platform_images/CHANGELOG.md

@@ -1,6 +1,7 @@
-## NEXT
+## 0.2.4
 
 * Updates minimum iOS version to 12.0 and minimum Flutter version to 3.16.6.
+* Adds Swift Package Manager compatibility.
 
 ## 0.2.3+2
 

packages/ios_platform_images/example/ios/Runner/AppDelegate.swift

@@ -5,7 +5,7 @@
 import Flutter
 import UIKit
 
-@UIApplicationMain
+@main
 @objc class AppDelegate: FlutterAppDelegate {
   override func application(
     _ application: UIApplication,

packages/ios_platform_images/ios/Assets/.gitkeep

@@ -16,6 +16,7 @@ Downloaded by pub (not CocoaPods).
   s.source           = { :http => 'https://github.com/flutter/packages/tree/main/packages/ios_platform_images' }
   s.documentation_url = 'https://pub.dev/packages/ios_platform_images'
   s.source_files = 'Classes/**/*.swift'
+  s.source_files = 'ios_platform_images/Sources/ios_platform_images/**/*.swift'
   s.dependency 'Flutter'
   s.platform = :ios, '12.0'
 
@@ -25,5 +26,5 @@ Downloaded by pub (not CocoaPods).
      'LD_RUNPATH_SEARCH_PATHS' => '/usr/lib/swift',
   }
   s.swift_version = '5.0'
-  s.resource_bundles = {'ios_platform_images_privacy' => ['Resources/PrivacyInfo.xcprivacy']}
+  s.resource_bundles = {'ios_platform_images_privacy' => ['ios_platform_images/Sources/ios_platform_images/Resources/PrivacyInfo.xcprivacy']}
 end

packages/ios_platform_images/ios/ios_platform_images.podspec

@@ -0,0 +1,28 @@
+// swift-tools-version: 5.9
+// The swift-tools-version declares the minimum version of Swift required to build this package.
+
+// 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 PackageDescription
+
+let package = Package(
+  name: "ios_platform_images",
+  platforms: [
+    .iOS("12.0")
+  ],
+  products: [
+    .library(name: "ios-platform-images", targets: ["ios_platform_images"])
+  ],
+  dependencies: [],
+  targets: [
+    .target(
+      name: "ios_platform_images",
+      dependencies: [],
+      resources: [
+        .process("Resources")
+      ]
+    )
+  ]
+)

packages/ios_platform_images/ios/ios_platform_images/Package.swift

@@ -6,7 +6,8 @@ import 'package:pigeon/pigeon.dart';
 
 @ConfigurePigeon(PigeonOptions(
   dartOut: 'lib/src/messages.g.dart',
-  swiftOut: 'ios/Classes/messages.g.swift',
+  swiftOut:
+      'ios/ios_platform_images/Sources/ios_platform_messages/messages.g.swift',
   copyrightHeader: 'pigeons/copyright.txt',
 ))