Select multiple images for upload at once

View Controllers/NewStatusViewController.swift

@@ -17,7 +17,7 @@ final class NewStatusViewController: UIViewController {
     private let postButton = UIBarButtonItem(title: nil, style: .done, target: nil, action: nil)
     private let mediaSelections = PassthroughSubject<[PHPickerResult], Never>()
     private let imagePickerResults = PassthroughSubject<[UIImagePickerController.InfoKey: Any]?, Never>()
-    private let documentPickerResuls = PassthroughSubject<[URL]?, Never>()
+    private let documentPickerResults = PassthroughSubject<[URL]?, Never>()
     private var cancellables = Set<AnyCancellable>()
 
     init(viewModel: NewStatusViewModel, rootViewModel: RootViewModel?) {
@@ -127,11 +127,11 @@ extension NewStatusViewController: UIImagePickerControllerDelegate {
 
 extension NewStatusViewController: UIDocumentPickerDelegate {
     func documentPicker(_ controller: UIDocumentPickerViewController, didPickDocumentsAt urls: [URL]) {
-        documentPickerResuls.send(urls)
+        documentPickerResults.send(urls)
     }
 
     func documentPickerWasCancelled(_ controller: UIDocumentPickerViewController) {
-        documentPickerResuls.send(nil)
+        documentPickerResults.send(nil)
     }
 }
 
@@ -282,19 +282,21 @@ private extension NewStatusViewController {
     }
 
     func presentMediaPicker(compositionViewModel: CompositionViewModel) {
-        mediaSelections.first().sink { [weak self] results in
+        mediaSelections.first().sink { [weak self] in
-            guard let self = self, let result = results.first else { return }
+            self?.viewModel.attach(itemProviders: $0.map(\.itemProvider), to: compositionViewModel)
-
-            self.viewModel.attach(itemProvider: result.itemProvider, to: compositionViewModel)
         }
         .store(in: &cancellables)
 
         var configuration = PHPickerConfiguration()
 
         configuration.preferredAssetRepresentationMode = .current
+        configuration.selectionLimit = CompositionViewModel.maxAttachmentCount
 
         if !compositionViewModel.canAddNonImageAttachment {
             configuration.filter = .images
+            configuration.selectionLimit = CompositionViewModel.maxAttachmentCount
+                - compositionViewModel.attachmentViewModels.count
+                - compositionViewModel.attachmentUploadViewModels.count
         }
 
         let picker = PHPickerViewController(configuration: configuration)
@@ -332,9 +334,9 @@ private extension NewStatusViewController {
             guard let self = self, let info = $0 else { return }
 
             if let url = info[.mediaURL] as? URL, let itemProvider = NSItemProvider(contentsOf: url) {
-                self.viewModel.attach(itemProvider: itemProvider, to: compositionViewModel)
+                self.viewModel.attach(itemProviders: [itemProvider], to: compositionViewModel)
             } else if let image = info[.editedImage] as? UIImage ?? info[.originalImage] as? UIImage {
-                self.viewModel.attach(itemProvider: NSItemProvider(object: image), to: compositionViewModel)
+                self.viewModel.attach(itemProviders: [NSItemProvider(object: image)], to: compositionViewModel)
             }
         }
         .store(in: &cancellables)
@@ -356,22 +358,27 @@ private extension NewStatusViewController {
     #endif
 
     func presentDocumentPicker(compositionViewModel: CompositionViewModel) {
-        documentPickerResuls.first().sink { [weak self] in
+        documentPickerResults.first().sink { [weak self] in
-            guard let self = self,
+            guard let self = self, let results = $0 else { return }
-                  let result = $0?.first,
-                  result.startAccessingSecurityScopedResource(),
-                  let itemProvider = NSItemProvider(contentsOf: result)
-            else { return }
 
-            self.viewModel.attach(itemProvider: itemProvider, to: compositionViewModel)
+            let itemProviders = results.compactMap { result -> NSItemProvider? in
+                guard result.startAccessingSecurityScopedResource() else { return nil }
+
+                return NSItemProvider(contentsOf: result)
+            }
+
+            self.viewModel.attach(itemProviders: itemProviders, to: compositionViewModel)
+
+            for result in results {
                 result.stopAccessingSecurityScopedResource()
             }
+        }
         .store(in: &cancellables)
 
         let documentPickerController = UIDocumentPickerViewController(forOpeningContentTypes: [.image, .movie, .audio])
 
         documentPickerController.delegate = self
-        documentPickerController.allowsMultipleSelection = false
+        documentPickerController.allowsMultipleSelection = true
         documentPickerController.modalPresentationStyle = .overFullScreen
         present(documentPickerController, animated: true)
     }

ViewModels/Sources/ViewModels/Entities/AttachmentUpload.swift

@@ -1,9 +1,37 @@
 // Copyright © 2020 Metabolist. All rights reserved.
 
+import Combine
 import Foundation
+import Mastodon
+import ServiceLayer
 
-public struct AttachmentUpload: Hashable {
+public class AttachmentUploadViewModel: ObservableObject {
-    public let progress: Progress
+    public let id = Id()
-    public let data: Data
+    public let progress = Progress(totalUnitCount: 1)
-    public let mimeType: String
+    public let parentViewModel: NewStatusViewModel
+
+    let data: Data
+    let mimeType: String
+    var cancellable: AnyCancellable?
+
+    init(data: Data, mimeType: String, parentViewModel: NewStatusViewModel) {
+        self.data = data
+        self.mimeType = mimeType
+        self.parentViewModel = parentViewModel
+    }
+}
+
+public extension AttachmentUploadViewModel {
+    typealias Id = UUID
+
+    func upload() -> AnyPublisher<Attachment, Error> {
+        parentViewModel.identityContext.service.uploadAttachment(
+            data: data,
+            mimeType: mimeType,
+            progress: progress)
+    }
+
+    func cancel() {
+        cancellable?.cancel()
+    }
 }

ViewModels/Sources/ViewModels/View Models/CompositionViewModel.swift

@@ -22,7 +22,7 @@ public final class CompositionViewModel: AttachmentsRenderingViewModel, Observab
     @Published public private(set) var contentWarningAutocompleteQuery: String?
     @Published public private(set) var pollOptions = [PollOption(text: ""), PollOption(text: "")]
     @Published public private(set) var attachmentViewModels = [AttachmentViewModel]()
-    @Published public private(set) var attachmentUpload: AttachmentUpload?
+    @Published public private(set) var attachmentUploadViewModels = [AttachmentUploadViewModel]()
     @Published public private(set) var isPostable = false
     @Published public private(set) var canAddAttachment = true
     @Published public private(set) var canAddNonImageAttachment = true
@@ -30,7 +30,7 @@ public final class CompositionViewModel: AttachmentsRenderingViewModel, Observab
     public let canRemoveAttachments = true
 
     private let eventsSubject: PassthroughSubject<Event, Never>
-    private var attachmentUploadCancellable: AnyCancellable?
+    private var cancellables = Set<AnyCancellable>()
 
     init(eventsSubject: PassthroughSubject<Event, Never>) {
         self.eventsSubject = eventsSubject
@@ -44,12 +44,17 @@ public final class CompositionViewModel: AttachmentsRenderingViewModel, Observab
             .assign(to: &$isPostable)
 
         $attachmentViewModels
-            .combineLatest($attachmentUpload, $displayPoll)
+            .combineLatest($attachmentUploadViewModels, $displayPoll)
-            .map { $0.count < Self.maxAttachmentCount && $1 == nil && !$2 }
+            .map { $0.count < Self.maxAttachmentCount && $1.isEmpty && !$2 }
             .assign(to: &$canAddAttachment)
 
         $attachmentViewModels.map(\.isEmpty).assign(to: &$canAddNonImageAttachment)
 
+        $attachmentUploadViewModels
+            .compactMap(\.first)
+            .sink { [weak self] in self?.upload(viewModel: $0) }
+            .store(in: &cancellables)
+
         $text.map {
             let tokens = $0.components(separatedBy: " ")
 
@@ -83,6 +88,7 @@ public final class CompositionViewModel: AttachmentsRenderingViewModel, Observab
 
 public extension CompositionViewModel {
     static let maxCharacters = 500
+    static let maxAttachmentCount = 4
     static let minPollOptionCount = 2
     static let maxPollOptionCount = 4
 
@@ -172,7 +178,7 @@ public extension CompositionViewModel {
                 self.text = text
             }
         } else if let itemProvider = inputItem.attachments?.first {
-            attach(itemProvider: itemProvider, parentViewModel: parentViewModel)
+            attach(itemProviders: [itemProvider], parentViewModel: parentViewModel)
         }
     }
 
@@ -197,39 +203,39 @@ public extension CompositionViewModel {
         pollOptions.removeAll { $0 === pollOption }
     }
 
-    func attach(itemProvider: NSItemProvider, parentViewModel: NewStatusViewModel) {
+    func attach(itemProviders: [NSItemProvider], parentViewModel: NewStatusViewModel) {
-        attachmentUploadCancellable = MediaProcessingService.dataAndMimeType(itemProvider: itemProvider)
+        Publishers.MergeMany(itemProviders.map {
-            .flatMap { [weak self] data, mimeType -> AnyPublisher<Attachment, Error> in
+            MediaProcessingService.dataAndMimeType(itemProvider: $0)
-                guard let self = self else { return Empty().eraseToAnyPublisher() }
-
-                let progress = Progress(totalUnitCount: 1)
-
-                DispatchQueue.main.async {
-                    self.attachmentUpload = AttachmentUpload(progress: progress, data: data, mimeType: mimeType)
-                }
-
-                return parentViewModel.identityContext.service.uploadAttachment(
-                    data: data,
-                    mimeType: mimeType,
-                    progress: progress)
-            }
                 .receive(on: DispatchQueue.main)
                 .assignErrorsToAlertItem(to: \.alertItem, on: parentViewModel)
-            .handleEvents(receiveCancel: { [weak self] in self?.attachmentUpload = nil })
+                .map { result in
+                    AttachmentUploadViewModel(
+                        data: result.data,
+                        mimeType: result.mimeType,
+                        parentViewModel: parentViewModel)
+                }
+        })
+        .collect()
+        .assign(to: &$attachmentUploadViewModels)
+    }
+
+    func upload(viewModel: AttachmentUploadViewModel) {
+        viewModel.cancellable = viewModel.upload()
+            .receive(on: DispatchQueue.main)
+            .assignErrorsToAlertItem(to: \.alertItem, on: viewModel.parentViewModel)
+            .handleEvents(receiveCancel: { [weak self] in
+                self?.attachmentUploadViewModels.removeAll { $0 === viewModel }
+            })
             .sink { [weak self] _ in
-                self?.attachmentUpload = nil
+                self?.attachmentUploadViewModels.removeAll { $0 === viewModel }
             } receiveValue: { [weak self] in
                 self?.attachmentViewModels.append(
                     AttachmentViewModel(
                         attachment: $0,
-                        identityContext: parentViewModel.identityContext))
+                        identityContext: viewModel.parentViewModel.identityContext))
             }
     }
 
-    func cancelUpload() {
-        attachmentUploadCancellable?.cancel()
-    }
-
     func update(attachmentViewModel: AttachmentViewModel) {
         let publisher = attachmentViewModel.updated()
             .receive(on: DispatchQueue.main)
@@ -259,7 +265,6 @@ public extension CompositionViewModel.PollOption {
 }
 
 private extension CompositionViewModel {
-    static let maxAttachmentCount = 4
     static let autocompleteQueryRegularExpression = #"([@#:]\S+)\z"#
     static let emojiOnlyAutocompleteQueryRegularExpression = #"(:\S+)\z"#
 

ViewModels/Sources/ViewModels/View Models/NewStatusViewModel.swift

@@ -187,8 +187,8 @@ public extension NewStatusViewModel {
         }
     }
 
-    func attach(itemProvider: NSItemProvider, to compositionViewModel: CompositionViewModel) {
+    func attach(itemProviders: [NSItemProvider], to compositionViewModel: CompositionViewModel) {
-        compositionViewModel.attach(itemProvider: itemProvider, parentViewModel: self)
+        compositionViewModel.attach(itemProviders: itemProviders, parentViewModel: self)
     }
 
     func post() {

Views/UIKit/AttachmentUploadView.swift

@@ -9,12 +9,10 @@ final class AttachmentUploadView: UIView {
     let cancelButton = UIButton(type: .system)
     let progressView = UIProgressView(progressViewStyle: .default)
 
-    private let viewModel: CompositionViewModel
+    private let viewModel: AttachmentUploadViewModel
-    private var progressCancellable: AnyCancellable?
     private var cancellables = Set<AnyCancellable>()
 
-    // swiftlint:disable:next function_body_length
+    init(viewModel: AttachmentUploadViewModel) {
-    init(viewModel: CompositionViewModel) {
         self.viewModel = viewModel
 
         super.init(frame: .zero)
@@ -33,7 +31,7 @@ final class AttachmentUploadView: UIView {
         cancelButton.titleLabel?.adjustsFontForContentSizeCategory = true
         cancelButton.titleLabel?.font = .preferredFont(forTextStyle: .callout)
         cancelButton.setTitle(NSLocalizedString("cancel", comment: ""), for: .normal)
-        cancelButton.addAction(UIAction { _ in viewModel.cancelUpload() }, for: .touchUpInside)
+        cancelButton.addAction(UIAction { _ in viewModel.cancel() }, for: .touchUpInside)
         cancelButton.accessibilityLabel =
             NSLocalizedString("compose.attachment.cancel-upload.accessibility-label", comment: "")
 
@@ -53,20 +51,9 @@ final class AttachmentUploadView: UIView {
             progressView.bottomAnchor.constraint(equalTo: layoutMarginsGuide.bottomAnchor)
         ])
 
-        viewModel.$attachmentUpload.sink { [weak self] attachmentUpload in
+        viewModel.progress.publisher(for: \.fractionCompleted)
-            guard let self = self else { return }
-
-            UIView.animate(withDuration: .zeroIfReduceMotion(.shortAnimationDuration)) {
-                if let attachmentUpload = attachmentUpload {
-                    self.progressCancellable = attachmentUpload.progress.publisher(for: \.fractionCompleted)
             .receive(on: DispatchQueue.main)
-                        .sink { self.progressView.progress = Float($0) }
+            .sink { [weak self] in self?.progressView.progress = Float($0) }
-                    self.isHidden = false
-                } else {
-                    self.isHidden = true
-                }
-            }
-        }
             .store(in: &cancellables)
     }
 
@@ -75,3 +62,7 @@ final class AttachmentUploadView: UIView {
         fatalError("init(coder:) has not been implemented")
     }
 }
+
+extension AttachmentUploadView {
+    var id: AttachmentUploadViewModel.Id { viewModel.id }
+}

Views/UIKit/CompositionInputAccessoryView.swift

@@ -205,8 +205,8 @@ private extension CompositionInputAccessoryView {
             .store(in: &cancellables)
 
         viewModel.$attachmentViewModels
-            .combineLatest(viewModel.$attachmentUpload)
+            .combineLatest(viewModel.$attachmentUploadViewModels)
-            .sink { pollButton.isEnabled = $0.isEmpty && $1 == nil }
+            .sink { pollButton.isEnabled = $0.isEmpty && $1.isEmpty }
             .store(in: &cancellables)
 
         viewModel.$remainingCharacters.sink {

Views/UIKit/CompositionView.swift

@@ -15,7 +15,7 @@ final class CompositionView: UIView {
     let inReplyToView = UIView()
     let hasReplyFollowingView = UIView()
     let attachmentsView = AttachmentsView()
-    let attachmentUploadView: AttachmentUploadView
+    let attachmentUploadsStackView = UIStackView()
     let pollView: CompositionPollView
     let markAttachmentsSensitiveView: MarkAttachmentsSensitiveView
 
@@ -27,7 +27,6 @@ final class CompositionView: UIView {
         self.viewModel = viewModel
         self.parentViewModel = parentViewModel
 
-        attachmentUploadView = AttachmentUploadView(viewModel: viewModel)
         markAttachmentsSensitiveView = MarkAttachmentsSensitiveView(viewModel: viewModel)
         pollView = CompositionPollView(viewModel: viewModel, parentViewModel: parentViewModel)
 
@@ -128,8 +127,9 @@ private extension CompositionView {
 
         stackView.addArrangedSubview(attachmentsView)
         attachmentsView.isHidden_stackViewSafe = true
-        stackView.addArrangedSubview(attachmentUploadView)
+        stackView.addArrangedSubview(attachmentUploadsStackView)
-        attachmentUploadView.isHidden_stackViewSafe = true
+        attachmentUploadsStackView.axis = .vertical
+        attachmentUploadsStackView.isHidden_stackViewSafe = true
         stackView.addArrangedSubview(markAttachmentsSensitiveView)
         markAttachmentsSensitiveView.isHidden_stackViewSafe = true
         stackView.addArrangedSubview(pollView)
@@ -227,10 +227,22 @@ private extension CompositionView {
             .sink { [weak self] in self?.textView.canPasteImage = $0 }
             .store(in: &cancellables)
 
+        viewModel.$attachmentUploadViewModels
+            .throttle(for: .seconds(TimeInterval.zeroIfReduceMotion(.shortAnimationDuration)),
+                      scheduler: DispatchQueue.main,
+                      latest: true)
+            .sink { [weak self] attachmentUploadViewModels in
+                UIView.animate(withDuration: .zeroIfReduceMotion(.shortAnimationDuration)) {
+                    self?.attachmentUploadsStackView.isHidden_stackViewSafe = attachmentUploadViewModels.isEmpty
+                    self?.update(attachmentUploadViewModels: attachmentUploadViewModels)
+                }
+            }
+            .store(in: &cancellables)
+
         textView.pastedItemProviders.sink { [weak self] in
             guard let self = self else { return }
 
-            self.viewModel.attach(itemProvider: $0,
+            self.viewModel.attach(itemProviders: [$0],
                                   parentViewModel: self.parentViewModel)
         }
         .store(in: &cancellables)
@@ -366,4 +378,29 @@ private extension CompositionView {
             range: textToSelectedRangeRange)
         spoilerTextFieldEditingChanged()
     }
+
+    func update(attachmentUploadViewModels: [AttachmentUploadViewModel]) {
+        let diff = attachmentUploadViewModels.map(\.id)
+            .difference(from: attachmentUploadsStackView
+                            .arrangedSubviews
+                            .compactMap { ($0 as? AttachmentUploadView)?.id })
+
+        for insertion in diff.insertions {
+            guard case let .insert(index, id, _) = insertion,
+                  let attachmentUploadViewModel = attachmentUploadViewModels.first(where: { $0.id == id })
+                  else { continue }
+
+            let attachmentUploadView = AttachmentUploadView(viewModel: attachmentUploadViewModel)
+
+            attachmentUploadsStackView.insertArrangedSubview(attachmentUploadView, at: index)
+        }
+
+        for removal in diff.removals {
+            guard case let .remove(_, id, _) = removal,
+                  let index = attachmentUploadsStackView.arrangedSubviews.firstIndex(where: { ($0 as? AttachmentUploadView)?.id == id })
+            else { continue }
+
+            attachmentUploadsStackView.arrangedSubviews[index].removeFromSuperview()
+        }
+    }
 }