Cancel uploads

HTTP/Sources/HTTP/URLSession+Extensions.swift

@@ -7,6 +7,8 @@ extension URLSession {
     func dataTaskPublisher(for request: URLRequest, progress: Progress?)
     -> AnyPublisher<DataTaskPublisher.Output, Error> {
         if let progress = progress {
+            var dataTaskReference: URLSessionDataTask?
+
             return Deferred {
                 Future<DataTaskPublisher.Output, Error> { promise in
                     let dataTask = self.dataTask(with: request) { data, response, error in
@@ -19,7 +21,11 @@ extension URLSession {
 
                     progress.addChild(dataTask.progress, withPendingUnitCount: 1)
                     dataTask.resume()
+                    dataTaskReference = dataTask
                 }
+                .handleEvents(receiveCancel: {
+                    dataTaskReference?.cancel()
+                })
             }
             .eraseToAnyPublisher()
         } else {

ViewModels/Sources/ViewModels/CompositionViewModel.swift

@@ -17,7 +17,7 @@ public final class CompositionViewModel: ObservableObject, Identifiable {
     @Published public private(set) var canAddAttachment = true
     @Published public private(set) var canAddNonImageAttachment = true
 
-    private var cancellables = Set<AnyCancellable>()
+    private var attachmentUploadCancellable: AnyCancellable?
 
     init() {
         $text.map { !$0.isEmpty }
@@ -56,11 +56,15 @@ public extension CompositionViewModel {
     func remove(attachmentViewModel: CompositionAttachmentViewModel) {
         attachmentViewModels.removeAll { $0 === attachmentViewModel }
     }
+
+    func cancelUpload() {
+        attachmentUploadCancellable?.cancel()
+    }
 }
 
 extension CompositionViewModel {
-    func attach(itemProvider: NSItemProvider, service: IdentityService) -> AnyPublisher<Never, Error> {
-        MediaProcessingService.dataAndMimeType(itemProvider: itemProvider)
+    func attach(itemProvider: NSItemProvider, parentViewModel: NewStatusViewModel) {
+        attachmentUploadCancellable = MediaProcessingService.dataAndMimeType(itemProvider: itemProvider)
             .flatMap { [weak self] data, mimeType -> AnyPublisher<Attachment, Error> in
                 guard let self = self else { return Empty().eraseToAnyPublisher() }
 
@@ -70,16 +74,19 @@ extension CompositionViewModel {
                     self.attachmentUpload = AttachmentUpload(progress: progress, data: data, mimeType: mimeType)
                 }
 
-                return service.uploadAttachment(data: data, mimeType: mimeType, progress: progress)
+                return parentViewModel.identification.service.uploadAttachment(
+                    data: data,
+                    mimeType: mimeType,
+                    progress: progress)
             }
             .receive(on: DispatchQueue.main)
-            .handleEvents(
-                receiveOutput: { [weak self] in
+            .assignErrorsToAlertItem(to: \.alertItem, on: parentViewModel)
+            .handleEvents(receiveCancel: { [weak self] in self?.attachmentUpload = nil })
+            .sink { [weak self] _ in
+                self?.attachmentUpload = nil
+            } receiveValue: { [weak self] in
                 self?.attachmentViewModels.append(CompositionAttachmentViewModel(attachment: $0))
-                },
-                receiveCompletion: { [weak self] _ in self?.attachmentUpload = nil })
-            .ignoreOutput()
-            .eraseToAnyPublisher()
+            }
     }
 }
 

ViewModels/Sources/ViewModels/NewStatusViewModel.swift

@@ -98,11 +98,7 @@ public extension NewStatusViewModel {
     }
 
     func attach(itemProvider: NSItemProvider, to compositionViewModel: CompositionViewModel) {
-        compositionViewModel.attach(itemProvider: itemProvider, service: identification.service)
-            .receive(on: DispatchQueue.main)
-            .assignErrorsToAlertItem(to: \.alertItem, on: self)
-            .sink { _ in }
-            .store(in: &cancellables)
+        compositionViewModel.attach(itemProvider: itemProvider, parentViewModel: self)
     }
 
     func post() {

Views/AttachmentUploadView.swift

@@ -6,23 +6,16 @@ import ViewModels
 
 final class AttachmentUploadView: UIView {
     let label = UILabel()
+    let cancelButton = UIButton(type: .system)
     let progressView = UIProgressView(progressViewStyle: .default)
+
+    private let viewModel: CompositionViewModel
     private var progressCancellable: AnyCancellable?
+    private var cancellables = Set<AnyCancellable>()
 
-    var attachmentUpload: AttachmentUpload? {
-        didSet {
-            if let attachmentUpload = attachmentUpload {
-                progressCancellable = attachmentUpload.progress.publisher(for: \.fractionCompleted)
-                    .receive(on: DispatchQueue.main)
-                    .sink { [weak self] in self?.progressView.progress = Float($0) }
-                isHidden = false
-            } else {
-                isHidden = true
-            }
-        }
-    }
+    init(viewModel: CompositionViewModel) {
+        self.viewModel = viewModel
 
-    init() {
         super.init(frame: .zero)
 
         addSubview(label)
@@ -34,18 +27,42 @@ final class AttachmentUploadView: UIView {
         label.textColor = .secondaryLabel
         label.numberOfLines = 0
 
+        addSubview(cancelButton)
+        cancelButton.translatesAutoresizingMaskIntoConstraints = false
+        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)
+
         addSubview(progressView)
         progressView.translatesAutoresizingMaskIntoConstraints = false
 
         NSLayoutConstraint.activate([
             label.leadingAnchor.constraint(equalTo: layoutMarginsGuide.leadingAnchor),
             label.topAnchor.constraint(equalTo: layoutMarginsGuide.topAnchor),
-            label.trailingAnchor.constraint(equalTo: layoutMarginsGuide.trailingAnchor),
+            label.trailingAnchor.constraint(equalTo: cancelButton.leadingAnchor, constant: .defaultSpacing),
+            cancelButton.topAnchor.constraint(equalTo: layoutMarginsGuide.topAnchor),
+            cancelButton.trailingAnchor.constraint(equalTo: layoutMarginsGuide.trailingAnchor),
+            cancelButton.bottomAnchor.constraint(equalTo: label.bottomAnchor),
             progressView.topAnchor.constraint(equalTo: label.bottomAnchor, constant: .defaultSpacing),
             progressView.leadingAnchor.constraint(equalTo: layoutMarginsGuide.leadingAnchor),
             progressView.trailingAnchor.constraint(equalTo: layoutMarginsGuide.trailingAnchor),
             progressView.bottomAnchor.constraint(equalTo: layoutMarginsGuide.bottomAnchor)
         ])
+
+        viewModel.$attachmentUpload.sink { [weak self] in
+            guard let self = self else { return }
+
+            if let attachmentUpload = $0 {
+                self.progressCancellable = attachmentUpload.progress.publisher(for: \.fractionCompleted)
+                    .receive(on: DispatchQueue.main)
+                    .sink { self.progressView.progress = Float($0) }
+                self.isHidden = false
+            } else {
+                self.isHidden = true
+            }
+        }
+        .store(in: &cancellables)
     }
 
     @available(*, unavailable)

Views/CompositionView.swift

@@ -10,8 +10,8 @@ final class CompositionView: UIView {
     let spoilerTextField = UITextField()
     let textView = UITextView()
     let textViewPlaceholder = UILabel()
-    let attachmentUploadView = AttachmentUploadView()
     let attachmentsCollectionView: UICollectionView
+    let attachmentUploadView: AttachmentUploadView
 
     private let viewModel: CompositionViewModel
     private let parentViewModel: NewStatusViewModel
@@ -50,6 +50,7 @@ final class CompositionView: UIView {
         let attachmentsLayout = UICollectionViewCompositionalLayout(section: section, configuration: configuration)
 
         attachmentsCollectionView = UICollectionView(frame: .zero, collectionViewLayout: attachmentsLayout)
+        attachmentUploadView = AttachmentUploadView(viewModel: viewModel)
 
         super.init(frame: .zero)
 
@@ -168,10 +169,6 @@ private extension CompositionView {
             }
             .store(in: &cancellables)
 
-        viewModel.$attachmentUpload
-            .sink { [weak self] in self?.attachmentUploadView.attachmentUpload = $0 }
-            .store(in: &cancellables)
-
         let guide = UIDevice.current.userInterfaceIdiom == .pad ? readableContentGuide : layoutMarginsGuide
         let constraints = [
             avatarImageView.heightAnchor.constraint(equalToConstant: .avatarDimension),