WIP Add SwiftUI Quickstart for Storage

storage/Podfile

@@ -1,15 +1,29 @@
 # StorageExample
 
 use_frameworks!
-platform :ios, '10.0'
-
-pod 'Firebase/Analytics'
-pod 'Firebase/Auth'
-pod 'Firebase/Storage'
 
 target 'StorageExample' do
+  platform :ios, '10.0'
+
+  pod 'Firebase/Analytics'
+  pod 'Firebase/Auth'
+  pod 'Firebase/Storage'
 end
 target 'StorageExampleSwift' do
+  platform :ios, '10.0'
+
+  pod 'Firebase/Analytics'
+  pod 'Firebase/Auth'
+  pod 'Firebase/Storage'
+  pod 'FirebaseStorageSwift', "~> 7.0-beta"
+end
+target 'StorageExampleSwiftUI' do
+  platform :ios, '13.0'
+
+  pod 'Firebase/Analytics'
+  pod 'Firebase/Auth'
+  pod 'Firebase/Storage'
+  pod 'FirebaseStorageSwift', "~> 7.0-beta"
   pod 'FirebaseStorageSwift', "~> 7.0-beta"
 end
 target 'StorageExampleTests' do

storage/Podfile.lock

@@ -119,6 +119,6 @@ SPEC CHECKSUMS:
   nanopb: 59221d7f958fb711001e6a449489542d92ae113e
   PromisesObjC: 3113f7f76903778cf4a0586bd1ab89329a0b7b97
 
-PODFILE CHECKSUM: 68e67a7f5b716247bf88b244cb2b3cc55d2e53ec
+PODFILE CHECKSUM: d7464278d730121dc09bc1404e6cbe6af4459ccc
 
 COCOAPODS: 1.10.1

storage/StorageExampleSwiftUI/ImagePicker.swift

@@ -0,0 +1,98 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import SwiftUI
+import Firebase
+
+/// ImagePickerRepresentable wraps a UIImagePickerController, so it is accessible through SwiftUI.
+struct ImagePickerRepresentable {
+    enum Source {
+        case camera
+        case photoLibrary
+    }
+
+    /// Denotes whether the user is taking a photo or selecting one.
+    var source: Source
+
+    /// Persistent storage which retains the image.
+    @ObservedObject var store: ImageStore
+
+    /// Binds to whether the image picker is visible.
+    @Binding var visible: Bool
+
+    /// Completion handler that is invoked when the image picker dismisses.
+    var completion: () -> Void
+
+    /// Coordinator is an internal class that acts as a delegate for the image picker.
+    class Coordinator: NSObject {
+        private var representable: ImagePickerRepresentable
+        private var store: ImageStore
+
+        init(representable: ImagePickerRepresentable, store: ImageStore) {
+            self.representable = representable
+            self.store = store
+        }
+    }
+}
+
+extension ImagePickerRepresentable: UIViewControllerRepresentable {
+    typealias UIViewControllerType = UIImagePickerController
+
+    /// Invoked by the system to setup a coordinator that the UIImagePickerViewController can use.
+    /// - Returns: The coordinator.
+    func makeCoordinator() -> Coordinator {
+        Coordinator(representable: self, store: self.store)
+    }
+
+    func makeUIViewController(context: Context) -> UIImagePickerController {
+        let imagePicker = UIImagePickerController()
+
+        switch self.source {
+        case .camera:
+            imagePicker.sourceType = .camera
+            imagePicker.cameraCaptureMode = .photo
+        case .photoLibrary:
+            imagePicker.sourceType = .photoLibrary
+        }
+
+        imagePicker.delegate = context.coordinator
+        return imagePicker
+    }
+
+    /// Required to implement, but unnecessary. We do not need to invalidate the SwiftUI canvas.
+    func updateUIViewController(_ uiViewController: UIImagePickerController, context: Context) { }
+}
+
+extension ImagePickerRepresentable.Coordinator: UIImagePickerControllerDelegate {
+    func imagePickerController(_ picker: UIImagePickerController, didFinishPickingMediaWithInfo info: [UIImagePickerController.InfoKey : Any]) {
+        guard let image = info[UIImagePickerController.InfoKey.originalImage] as? UIImage else { return }
+
+        let imagePath = "\(Auth.auth().currentUser!.uid)/\(Int(Date.timeIntervalSinceReferenceDate * 1000)).jpg"
+        self.store.uploadImage(image, atPath: imagePath)
+        // TODO: Move UserDefaults and imagePath logic into store.
+        UserDefaults.standard.setValue(imagePath, forKey: self.store.imagePathKey)
+
+        self.store.image = image
+        self.representable.visible = false
+        picker.dismiss(animated: true, completion: self.representable.completion)
+    }
+
+    func imagePickerControllerDidCancel(_ picker: UIImagePickerController) {
+        self.representable.visible = false
+        picker.dismiss(animated: true, completion: self.representable.completion)
+    }
+}
+
+/// The coordinator must implement the UINavigationControllerDelegate protocol in order to be the UIImagePickerController's delegate.
+extension ImagePickerRepresentable.Coordinator: UINavigationControllerDelegate { }

storage/StorageExampleSwiftUI/ImageStore.swift

@@ -0,0 +1,77 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import Firebase
+import FirebaseStorageSwift
+
+/// ImageStore facilitates saving and downloading images.
+public class ImageStore: ObservableObject {
+    /// Reference to Firebase storage.
+    private var storage: Storage
+
+    /// Quality for JPEG images where 1.0 is the best quality and 0.0 is the worst.
+    public var compressionQuality: CGFloat = 0.8
+
+    /// UserDefaults key that will have a value containing the path of the last image.
+    public let imagePathKey = "imagePath"
+
+    /// Binds to the current image.
+    @Published var image: UIImage?
+
+    lazy var localImageFileDirectory: String = {
+        let paths = NSSearchPathForDirectoriesInDomains(.documentDirectory, .userDomainMask, true)
+        let documentsDirectory = paths[0]
+        return "file:\(documentsDirectory)"
+    }()
+
+    public init(storage: Storage) {
+        self.storage = storage
+    }
+
+    /// Uploads an image to Firebase storage.
+    /// - Parameters:
+    ///   - image: Image to upload.
+    ///   - imagePath: Path of the image in Firebase storage.
+    public func uploadImage(_ image: UIImage, atPath imagePath: String) {
+        guard let imageData = image.jpegData(compressionQuality: compressionQuality) else { return }
+
+        let imageMetadata = StorageMetadata()
+        imageMetadata.contentType = "image/jpeg"
+
+        let storageRef = storage.reference(withPath: imagePath)
+        storageRef.putData(imageData, metadata: imageMetadata) { result in
+            switch result {
+            case .success:
+                break
+            case let .failure(error):
+                _ = error
+                break
+            }
+        }
+    }
+
+    /// Downloads an image from Firebase storage.
+    /// - Parameter imagePath: Path of the image in Firebase storage.
+    public func downloadImage(atPath imagePath: String) {
+        guard let imageURL = URL(string: "\(self.localImageFileDirectory)/\(imagePath)") else { return }
+        self.storage.reference().child(imagePath).write(toFile: imageURL) { result in
+            switch result {
+            case let .success(downloadedFileURL):
+                self.image = UIImage(contentsOfFile: downloadedFileURL.path)
+            case let .failure(error):
+                print("Error downloading: \(error)")
+            }
+        }
+    }
+}

storage/StorageExampleSwiftUI/ImageView.swift

@@ -0,0 +1,95 @@
+// Copyright 2021 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+import SwiftUI
+import Firebase
+
+/// ImageView provides the main content for the app. It displays a current image and provides controls to change
+/// it by taking a new one with the camera, selecting one from the photo library or downloading one from Firebase
+/// storage.
+struct ImageView: View {
+    /// Manages retrieval and persistence of the current image.
+    @StateObject private var photoStore = ImageStore(storage: Storage.storage())
+
+    /// Indicates whether the user is selecting an image from the photo library.
+    @State var isSelectingImage = false
+
+    /// Indicates whether the user is taking an image using the camera.
+    @State var isTakingPhoto = false
+
+    /// Indicates whether a submenu that allows the user to choose whether to select or take a photo should be
+    /// visible.
+    @State var showUploadMenu = false
+
+    var body: some View {
+        NavigationView {
+            VStack {
+                Image(uiImage: photoStore.image ?? UIImage())
+                    .resizable()
+                    .aspectRatio(contentMode: .fit)
+            }
+            .navigationTitle("Firebase Storage")
+            .toolbar {
+                ToolbarItemGroup(placement: .bottomBar) {
+                    if showUploadMenu {
+                        Button("❌") {
+                            showUploadMenu = false
+                        }
+
+                        Spacer()
+
+                        Button("Take Photo") {
+                            isTakingPhoto = true
+                        }.sheet(isPresented: $isTakingPhoto) {
+                            ImagePickerRepresentable(source: .camera, store: photoStore, visible: $isTakingPhoto, completion: {
+                                showUploadMenu = false
+                            })
+                        }.disabled(!UIImagePickerController.isSourceTypeAvailable(.camera))
+
+                        Button("Select Image") {
+                            isSelectingImage = true
+                        }.sheet(isPresented: $isSelectingImage) {
+                            ImagePickerRepresentable(source: .photoLibrary, store: photoStore, visible: $isSelectingImage, completion: {
+                                showUploadMenu = false
+                            })
+                        }
+                    } else {
+                        Button("Upload") {
+                            showUploadMenu = true
+                        }
+                        Spacer()
+                        Button("Download") {
+                            self.downloadImage()
+                        }
+                    }
+                }
+            }
+        }.onAppear {
+            downloadImage()
+        }
+    }
+
+    // TODO: Move this logic into the store, relying on its binding alone.
+    func downloadImage() {
+        if let imagePath = UserDefaults.standard.string(forKey: self.photoStore.imagePathKey) {
+            self.photoStore.downloadImage(atPath: imagePath)
+        }
+    }
+}
+
+struct ContentView_Previews: PreviewProvider {
+    static var previews: some View {
+        ImageView()
+    }
+}

storage/StorageExampleSwiftUI/Info.plist

@@ -0,0 +1,54 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>$(DEVELOPMENT_LANGUAGE)</string>
+	<key>CFBundleExecutable</key>
+	<string>$(EXECUTABLE_NAME)</string>
+	<key>CFBundleIdentifier</key>
+	<string>$(PRODUCT_BUNDLE_IDENTIFIER)</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>$(PRODUCT_NAME)</string>
+	<key>CFBundlePackageType</key>
+	<string>$(PRODUCT_BUNDLE_PACKAGE_TYPE)</string>
+	<key>CFBundleShortVersionString</key>
+	<string>1.0</string>
+	<key>CFBundleVersion</key>
+	<string>1</string>
+	<key>LSRequiresIPhoneOS</key>
+	<true/>
+	<key>NSCameraUsageDescription</key>
+	<string>Take and upload photos to cloud storage</string>
+	<key>NSPhotoLibraryUsageDescription</key>
+	<string>Upload photos to cloud storage</string>
+	<key>UIApplicationSceneManifest</key>
+	<dict>
+		<key>UIApplicationSupportsMultipleScenes</key>
+		<true/>
+	</dict>
+	<key>UIApplicationSupportsIndirectInputEvents</key>
+	<true/>
+	<key>UILaunchScreen</key>
+	<dict/>
+	<key>UIRequiredDeviceCapabilities</key>
+	<array>
+		<string>armv7</string>
+	</array>
+	<key>UISupportedInterfaceOrientations</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
+	</array>
+	<key>UISupportedInterfaceOrientations~ipad</key>
+	<array>
+		<string>UIInterfaceOrientationPortrait</string>
+		<string>UIInterfaceOrientationPortraitUpsideDown</string>
+		<string>UIInterfaceOrientationLandscapeLeft</string>
+		<string>UIInterfaceOrientationLandscapeRight</string>
+	</array>
+</dict>
+</plist>

storage/StorageExampleSwiftUI/Preview Content/Preview Assets.xcassets/Contents.json

@@ -0,0 +1,6 @@
+{
+  "info" : {
+    "author" : "xcode",
+    "version" : 1
+  }
+}