Edit attachments

Extensions/UIView+Extensions.swift

@@ -0,0 +1,28 @@
+// Copyright © 2021 Metabolist. All rights reserved.
+
+import Mastodon
+import UIKit
+
+extension UIView {
+    private static let defaultContentsRectSize = CGSize(width: 1, height: 1)
+
+    func setContentsRect(focus: Attachment.Meta.Focus, mediaSize: CGSize) {
+        let aspectRatio = mediaSize.width / mediaSize.height
+        let viewAspectRatio = bounds.width / bounds.height
+        var origin = CGPoint.zero
+
+        if viewAspectRatio > aspectRatio {
+            let mediaProportionalHeight = mediaSize.height * bounds.width / mediaSize.width
+            let maxPan = (mediaProportionalHeight - bounds.height) / (2 * mediaProportionalHeight)
+
+            origin.y = CGFloat(-focus.y) * maxPan
+        } else {
+            let mediaProportionalWidth = mediaSize.width * bounds.height / mediaSize.height
+            let maxPan = (mediaProportionalWidth - bounds.width) / (2 * mediaProportionalWidth)
+
+            origin.x = CGFloat(focus.x) * maxPan
+        }
+
+        layer.contentsRect = CGRect(origin: origin, size: Self.defaultContentsRectSize)
+    }
+}

Localizations/Localizable.strings

@@ -31,6 +31,11 @@
 "add-identity.join" = "Join";
 "add-identity.request-invite" = "Request an invite";
 "add-identity.unable-to-connect-to-instance" = "Unable to connect to instance";
+"attachment.edit.description" = "Describe for the visually impaired";
+"attachment.edit.description.audio" = "Describe for people with hearing loss";
+"attachment.edit.description.video" = "Describe for people with hearing loss or visual impairment";
+"attachment.edit.title" = "Edit media";
+"attachment.edit.thumbnail.prompt" = "Drag the circle on the preview to choose the focal point which will always be in view on all thumbnails";
 "attachment.sensitive-content" = "Sensitive content";
 "attachment.media-hidden" = "Media hidden";
 "bookmarks" = "Bookmarks";

Mastodon/Sources/Mastodon/Entities/Attachment.swift

@@ -22,8 +22,8 @@ public struct Attachment: Codable, Hashable {
         }
 
         public struct Focus: Codable, Hashable {
-            public let x: Double
+            public var x: Double
-            public let y: Double
+            public var y: Double
         }
 
         public let original: Info?
@@ -60,3 +60,7 @@ public extension Attachment {
         return nil
     }
 }
+
+public extension Attachment.Meta.Focus {
+    static let `default` = Self(x: 0, y: 0)
+}

MastodonAPI/Sources/MastodonAPI/Endpoints/AttachmentEndpoint.swift

@@ -6,6 +6,7 @@ import Mastodon
 
 public enum AttachmentEndpoint {
     case create(data: Data, mimeType: String, description: String?, focus: Attachment.Meta.Focus?)
+    case update(id: Attachment.Id, description: String?, focus: Attachment.Meta.Focus?)
 }
 
 extension AttachmentEndpoint: Endpoint {
@@ -19,6 +20,8 @@ extension AttachmentEndpoint: Endpoint {
         switch self {
         case .create:
             return []
+        case let .update(id, _, _):
+            return [id]
         }
     }
 
@@ -37,6 +40,18 @@ extension AttachmentEndpoint: Endpoint {
                 params["focus"] = .string("\(focus.x),\(focus.y)")
             }
 
+            return params
+        case let .update(_, description, focus):
+            var params = [String: MultipartFormValue]()
+
+            if let description = description {
+                params["description"] = .string(description)
+            }
+
+            if let focus = focus {
+                params["focus"] = .string("\(focus.x),\(focus.y)")
+            }
+
             return params
         }
     }
@@ -45,6 +60,8 @@ extension AttachmentEndpoint: Endpoint {
         switch self {
         case .create:
             return .post
+        case .update:
+            return .put
         }
     }
 }

Metatext.xcodeproj/project.pbxproj

@@ -36,6 +36,14 @@
 		D03B1B2A253818F3008F964B /* MediaPreferencesView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D03B1B29253818F3008F964B /* MediaPreferencesView.swift */; };
 		D04226FD2546AC0B000980A3 /* StartupAndSyncingPreferencesView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D04226FC2546AC0B000980A3 /* StartupAndSyncingPreferencesView.swift */; };
 		D04F9E8E259E9C950081B0C9 /* ViewModels in Frameworks */ = {isa = PBXBuildFile; productRef = D04F9E8D259E9C950081B0C9 /* ViewModels */; };
+		D05936CF25A8D79800754FDF /* EditAttachmentViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D05936CE25A8D79800754FDF /* EditAttachmentViewController.swift */; };
+		D05936D025A8D79800754FDF /* EditAttachmentViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D05936CE25A8D79800754FDF /* EditAttachmentViewController.swift */; };
+		D05936DE25A937EC00754FDF /* EditThumbnailView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D05936DD25A937EC00754FDF /* EditThumbnailView.swift */; };
+		D05936DF25A937EC00754FDF /* EditThumbnailView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D05936DD25A937EC00754FDF /* EditThumbnailView.swift */; };
+		D05936E925AA3F3D00754FDF /* EditAttachmentView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D05936E825AA3F3D00754FDF /* EditAttachmentView.swift */; };
+		D05936EA25AA3F3D00754FDF /* EditAttachmentView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D05936E825AA3F3D00754FDF /* EditAttachmentView.swift */; };
+		D05936F425AA66A600754FDF /* UIView+Extensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = D05936F325AA66A600754FDF /* UIView+Extensions.swift */; };
+		D05936F525AA66A600754FDF /* UIView+Extensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = D05936F325AA66A600754FDF /* UIView+Extensions.swift */; };
 		D0625E59250F092900502611 /* StatusListCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0625E58250F092900502611 /* StatusListCell.swift */; };
 		D0625E5D250F0B5C00502611 /* StatusContentConfiguration.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0625E5C250F0B5C00502611 /* StatusContentConfiguration.swift */; };
 		D06BC5E625202AD90079541D /* ProfileViewController.swift in Sources */ = {isa = PBXBuildFile; fileRef = D06BC5E525202AD90079541D /* ProfileViewController.swift */; };
@@ -181,6 +189,10 @@
 		D03B1B29253818F3008F964B /* MediaPreferencesView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MediaPreferencesView.swift; sourceTree = "<group>"; };
 		D04226FC2546AC0B000980A3 /* StartupAndSyncingPreferencesView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StartupAndSyncingPreferencesView.swift; sourceTree = "<group>"; };
 		D047FA8C24C3E21200AF17C5 /* Metatext.app */ = {isa = PBXFileReference; explicitFileType = wrapper.application; includeInIndex = 0; path = Metatext.app; sourceTree = BUILT_PRODUCTS_DIR; };
+		D05936CE25A8D79800754FDF /* EditAttachmentViewController.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EditAttachmentViewController.swift; sourceTree = "<group>"; };
+		D05936DD25A937EC00754FDF /* EditThumbnailView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EditThumbnailView.swift; sourceTree = "<group>"; };
+		D05936E825AA3F3D00754FDF /* EditAttachmentView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = EditAttachmentView.swift; sourceTree = "<group>"; };
+		D05936F325AA66A600754FDF /* UIView+Extensions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UIView+Extensions.swift"; sourceTree = "<group>"; };
 		D0625E58250F092900502611 /* StatusListCell.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StatusListCell.swift; sourceTree = "<group>"; };
 		D0625E5C250F0B5C00502611 /* StatusContentConfiguration.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = StatusContentConfiguration.swift; sourceTree = "<group>"; };
 		D0666A2124C677B400F3F04B /* Tests.xctest */ = {isa = PBXFileReference; explicitFileType = wrapper.cfbundle; includeInIndex = 0; path = Tests.xctest; sourceTree = BUILT_PRODUCTS_DIR; };
@@ -442,7 +454,9 @@
 				D00702302555F4AE00F38136 /* ConversationView.swift */,
 				D0C7D42324F76169001EBDBB /* CustomEmojiText.swift */,
 				D08E52602579D2E100FA2C5F /* DomainBlocksView.swift */,
+				D05936E825AA3F3D00754FDF /* EditAttachmentView.swift */,
 				D0BEB21024FA2A90001B0F04 /* EditFilterView.swift */,
+				D05936DD25A937EC00754FDF /* EditThumbnailView.swift */,
 				D0BEB20424FA1107001B0F04 /* FiltersView.swift */,
 				D0C7D42224F76169001EBDBB /* IdentitiesView.swift */,
 				D0BEB1FE24F9E5BB001B0F04 /* ListsView.swift */,
@@ -482,6 +496,7 @@
 		D0C7D43024F76169001EBDBB /* View Controllers */ = {
 			isa = PBXGroup;
 			children = (
+				D05936CE25A8D79800754FDF /* EditAttachmentViewController.swift */,
 				D08B8D49253FC36500B1EBEF /* ImageNavigationController.swift */,
 				D08B8D41253F92B600B1EBEF /* ImagePageViewController.swift */,
 				D08B8D3C253F929E00B1EBEF /* ImageViewController.swift */,
@@ -522,6 +537,7 @@
 				D0C7D46A24F76169001EBDBB /* String+Extensions.swift */,
 				D08E512025786A6600FA2C5F /* UIButton+Extensions.swift */,
 				D0C7D46C24F76169001EBDBB /* UIColor+Extensions.swift */,
+				D05936F325AA66A600754FDF /* UIView+Extensions.swift */,
 				D0E7AD3825870B13005F5E2D /* UIVIewController+Extensions.swift */,
 				D0030981250C6C8500EACB32 /* URL+Extensions.swift */,
 				D0C7D46F24F76169001EBDBB /* View+Extensions.swift */,
@@ -760,6 +776,7 @@
 				D08E52EE257D757100FA2C5F /* CompositionView.swift in Sources */,
 				D0E569E0252931B100FA1D72 /* LoadMoreContentConfiguration.swift in Sources */,
 				D0FE1C9825368A9D003EF1EB /* PlayerCache.swift in Sources */,
+				D05936DE25A937EC00754FDF /* EditThumbnailView.swift in Sources */,
 				D0F0B136251AA12700942152 /* CollectionItem+Extensions.swift in Sources */,
 				D007023E25562A2800F38136 /* ConversationAvatarsView.swift in Sources */,
 				D0E7AD3925870B13005F5E2D /* UIVIewController+Extensions.swift in Sources */,
@@ -789,6 +806,7 @@
 				D0C7D4DA24F7616A001EBDBB /* View+Extensions.swift in Sources */,
 				D08B8D8D2544E6EC00B1EBEF /* PollResultView.swift in Sources */,
 				D0C7D4D524F7616A001EBDBB /* String+Extensions.swift in Sources */,
+				D05936CF25A8D79800754FDF /* EditAttachmentViewController.swift in Sources */,
 				D0C7D4A224F7616A001EBDBB /* NotificationTypesPreferencesView.swift in Sources */,
 				D00702362555F4C500F38136 /* ConversationContentConfiguration.swift in Sources */,
 				D0BEB1F724F9A84B001B0F04 /* LoadingTableFooterView.swift in Sources */,
@@ -803,6 +821,8 @@
 				D01EF22425182B1F00650C6B /* AccountHeaderView.swift in Sources */,
 				D036AA17254CA824009094DF /* StatusBodyView.swift in Sources */,
 				D08E512125786A6600FA2C5F /* UIButton+Extensions.swift in Sources */,
+				D05936F425AA66A600754FDF /* UIView+Extensions.swift in Sources */,
+				D05936E925AA3F3D00754FDF /* EditAttachmentView.swift in Sources */,
 				D0EA59482522B8B600804347 /* ViewConstants.swift in Sources */,
 				D04226FD2546AC0B000980A3 /* StartupAndSyncingPreferencesView.swift in Sources */,
 				D036AA0C254B612B009094DF /* NotificationContentConfiguration.swift in Sources */,
@@ -847,20 +867,24 @@
 				D08E52A6257C61C000FA2C5F /* ShareExtensionNavigationViewController.swift in Sources */,
 				D08E52D2257C811200FA2C5F /* ShareExtensionError+Extensions.swift in Sources */,
 				D0E9F9AB258450B300EF503D /* CompositionInputAccessoryView.swift in Sources */,
+				D05936D025A8D79800754FDF /* EditAttachmentViewController.swift in Sources */,
 				D038273C259EA38F00056E0F /* NewStatusView.swift in Sources */,
 				D08E52EF257D757100FA2C5F /* CompositionView.swift in Sources */,
 				D0CE9F88258B076900E3A6B6 /* AttachmentUploadView.swift in Sources */,
 				D08E52C7257C7AEE00FA2C5F /* ShareErrorViewController.swift in Sources */,
 				D015B14425A812F6006D88A8 /* PlayerCache.swift in Sources */,
+				D05936F525AA66A600754FDF /* UIView+Extensions.swift in Sources */,
 				D015B13F25A812EC006D88A8 /* PlayerView.swift in Sources */,
 				D015B13A25A812E6006D88A8 /* AttachmentView.swift in Sources */,
 				D08E52F8257D78BE00FA2C5F /* ViewConstants.swift in Sources */,
 				D036EBC2259FE2AD00EC1CFC /* UIVIewController+Extensions.swift in Sources */,
 				D015B13525A812DD006D88A8 /* AttachmentsView.swift in Sources */,
+				D05936EA25AA3F3D00754FDF /* EditAttachmentView.swift in Sources */,
 				D0FCC106259C4E62000B67DF /* NewStatusViewController.swift in Sources */,
 				D036EBBD259FE2A100EC1CFC /* Array+Extensions.swift in Sources */,
 				D036EBB3259FE28800EC1CFC /* UIColor+Extensions.swift in Sources */,
 				D036EBB8259FE29800EC1CFC /* Status+Extensions.swift in Sources */,
+				D05936DF25A937EC00754FDF /* EditThumbnailView.swift in Sources */,
 			);
 			runOnlyForDeploymentPostprocessing = 0;
 		};

ServiceLayer/Sources/ServiceLayer/Services/IdentityService.swift

@@ -212,6 +212,12 @@ public extension IdentityService {
             progress: progress)
     }
 
+    func updateAttachment(id: Attachment.Id,
+                          description: String,
+                          focus: Attachment.Meta.Focus) -> AnyPublisher<Attachment, Error> {
+        mastodonAPIClient.request(AttachmentEndpoint.update(id: id, description: description, focus: focus))
+    }
+
     func post(statusComponents: StatusComponents) -> AnyPublisher<Status.Id, Error> {
         mastodonAPIClient.request(StatusEndpoint.post(statusComponents)).map(\.id).eraseToAnyPublisher()
     }

View Controllers/EditAttachmentViewController.swift

@@ -0,0 +1,127 @@
+// Copyright © 2021 Metabolist. All rights reserved.
+
+import Combine
+import UIKit
+import ViewModels
+
+final class EditAttachmentViewController: UIViewController {
+    private let viewModel: AttachmentViewModel
+    private let parentViewModel: CompositionViewModel
+    private var cancellables = Set<AnyCancellable>()
+
+    init(viewModel: AttachmentViewModel, parentViewModel: CompositionViewModel) {
+        self.viewModel = viewModel
+        self.parentViewModel = parentViewModel
+
+        super.init(nibName: nil, bundle: nil)
+    }
+
+    @available(*, unavailable)
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+
+    // swiftlint:disable:next function_body_length
+    override func viewDidLoad() {
+        super.viewDidLoad()
+
+        view.backgroundColor = .systemBackground
+
+        let editThumbnailView = EditThumbnailView(viewModel: viewModel)
+
+        view.addSubview(editThumbnailView)
+        editThumbnailView.translatesAutoresizingMaskIntoConstraints = false
+
+        let stackView = UIStackView()
+
+        view.addSubview(stackView)
+        stackView.translatesAutoresizingMaskIntoConstraints = false
+        stackView.axis = .vertical
+        stackView.spacing = .defaultSpacing
+
+        let describeLabel = UILabel()
+
+        stackView.addArrangedSubview(describeLabel)
+        describeLabel.adjustsFontForContentSizeCategory = true
+        describeLabel.font = .preferredFont(forTextStyle: .headline)
+        describeLabel.numberOfLines = 0
+        describeLabel.textAlignment = .center
+
+        switch viewModel.attachment.type {
+        case .audio:
+            describeLabel.text = NSLocalizedString("attachment.edit.description.audio", comment: "")
+        case .video:
+            describeLabel.text = NSLocalizedString("attachment.edit.description.video", comment: "")
+        default:
+            describeLabel.text = NSLocalizedString("attachment.edit.description", comment: "")
+        }
+
+        let textView = UITextView()
+
+        stackView.addArrangedSubview(textView)
+        textView.adjustsFontForContentSizeCategory = true
+        textView.font = .preferredFont(forTextStyle: .body)
+        textView.layer.borderWidth = .hairline
+        textView.layer.borderColor = UIColor.separator.cgColor
+        textView.layer.cornerRadius = .defaultCornerRadius
+        textView.delegate = self
+        textView.text = viewModel.editingDescription
+
+        let remainingCharactersLabel = UILabel()
+
+        stackView.addArrangedSubview(remainingCharactersLabel)
+        remainingCharactersLabel.adjustsFontForContentSizeCategory = true
+        remainingCharactersLabel.font = .preferredFont(forTextStyle: .subheadline)
+        remainingCharactersLabel.text = "1500"
+
+        NSLayoutConstraint.activate([
+            stackView.leadingAnchor.constraint(equalTo: view.layoutMarginsGuide.leadingAnchor),
+            stackView.topAnchor.constraint(equalTo: view.layoutMarginsGuide.topAnchor, constant: .defaultSpacing),
+            editThumbnailView.leadingAnchor.constraint(equalTo: stackView.trailingAnchor, constant: .defaultSpacing),
+            stackView.bottomAnchor.constraint(
+                equalTo: view.layoutMarginsGuide.bottomAnchor,
+                constant: -.defaultSpacing),
+            editThumbnailView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor),
+            editThumbnailView.trailingAnchor.constraint(equalTo: view.safeAreaLayoutGuide.trailingAnchor),
+            editThumbnailView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.bottomAnchor),
+            editThumbnailView.widthAnchor.constraint(equalTo: stackView.widthAnchor, multiplier: 3 / 2)
+        ])
+
+        viewModel.$descriptionRemainingCharacters
+            .sink {
+                remainingCharactersLabel.text = String($0)
+                remainingCharactersLabel.textColor = $0 < 0 ? .systemRed : .label
+            }
+            .store(in: &cancellables)
+
+        textView.becomeFirstResponder()
+    }
+
+    override func didMove(toParent parent: UIViewController?) {
+        super.didMove(toParent: parent)
+
+        let cancelButton = UIBarButtonItem(
+            systemItem: .cancel,
+            primaryAction: UIAction { [weak self] _ in
+                self?.presentingViewController?.dismiss(animated: true)
+            })
+        let doneButton = UIBarButtonItem(
+            systemItem: .done,
+            primaryAction: UIAction { [weak self] _ in
+                guard let self = self else { return }
+
+                self.parentViewModel.update(attachmentViewModel: self.viewModel)
+                self.presentingViewController?.dismiss(animated: true)
+            })
+
+        parent?.navigationItem.leftBarButtonItem = cancelButton
+        parent?.navigationItem.rightBarButtonItem = doneButton
+        parent?.navigationItem.title = NSLocalizedString("attachment.edit.title", comment: "")
+    }
+}
+
+extension EditAttachmentViewController: UITextViewDelegate {
+    func textViewDidChange(_ textView: UITextView) {
+        viewModel.editingDescription = textView.text
+    }
+}

View Controllers/NewStatusViewController.swift

@@ -4,7 +4,7 @@ import AVFoundation
 import Combine
 import Kingfisher
 import PhotosUI
-import UIKit
+import SwiftUI
 import UniformTypeIdentifiers
 import ViewModels
 
@@ -110,6 +110,10 @@ private extension NewStatusViewController {
             #if !IS_SHARE_EXTENSION
             presentCamera(compositionViewModel: compositionViewModel)
             #endif
+        case let .editAttachment(attachmentViewModel, compositionViewModel):
+            presentAttachmentEditor(
+                attachmentViewModel: attachmentViewModel,
+                compositionViewModel: compositionViewModel)
         }
     }
 
@@ -276,6 +280,15 @@ private extension NewStatusViewController {
     }
     #endif
 
+    func presentAttachmentEditor(attachmentViewModel: AttachmentViewModel, compositionViewModel: CompositionViewModel) {
+        let editAttachmentsView = EditAttachmentView { (attachmentViewModel, compositionViewModel) }
+        let editAttachmentViewController = UIHostingController(rootView: editAttachmentsView)
+        let navigationController = UINavigationController(rootViewController: editAttachmentViewController)
+
+        navigationController.modalPresentationStyle = .overFullScreen
+        present(navigationController, animated: true)
+    }
+
     func changeIdentityButton(identification: Identification) -> UIButton {
         let changeIdentityButton = UIButton()
         let downsampled = KingfisherOptionsInfo.downsampled(

ViewModels/Sources/ViewModels/AttachmentViewModel.swift

@@ -1,11 +1,15 @@
 // Copyright © 2020 Metabolist. All rights reserved.
 
+import Combine
 import Foundation
 import Mastodon
 import Network
 
 public final class AttachmentViewModel: ObservableObject {
     public let attachment: Attachment
+    @Published public var editingDescription: String
+    @Published public var editingFocus: Attachment.Meta.Focus
+    @Published public private(set) var descriptionRemainingCharacters = AttachmentViewModel.descriptionMaxCharacters
 
     private let identification: Identification
     private let status: Status?
@@ -14,6 +18,11 @@ public final class AttachmentViewModel: ObservableObject {
         self.attachment = attachment
         self.identification = identification
         self.status = status
+        editingDescription = attachment.description ?? ""
+        editingFocus = attachment.meta?.focus ?? .default
+        $editingDescription
+            .map { Self.descriptionMaxCharacters - $0.count }
+            .assign(to: &$descriptionRemainingCharacters)
     }
 }
 
@@ -37,7 +46,21 @@ public extension AttachmentViewModel {
     }
 }
 
+extension AttachmentViewModel {
+    func updated() -> AnyPublisher<AttachmentViewModel, Error> {
+        identification.service.updateAttachment(id: attachment.id, description: editingDescription, focus: editingFocus)
+            .compactMap { [weak self] in
+                guard let self = self else { return nil }
+
+                return AttachmentViewModel(attachment: $0, identification: self.identification, status: self.status)
+            }
+            .eraseToAnyPublisher()
+    }
+}
+
 private extension AttachmentViewModel {
+    static let descriptionMaxCharacters = 1500
+
     static var wifiMonitor: NWPathMonitor = {
         let monitor = NWPathMonitor(requiredInterfaceType: .wifi)
 

ViewModels/Sources/ViewModels/CompositionViewModel.swift

@@ -19,9 +19,12 @@ public final class CompositionViewModel: AttachmentsRenderingViewModel, Observab
     @Published public private(set) var remainingCharacters = CompositionViewModel.maxCharacters
     public let canRemoveAttachments = true
 
+    private let eventsSubject: PassthroughSubject<Event, Never>
     private var attachmentUploadCancellable: AnyCancellable?
 
-    init() {
+    init(eventsSubject: PassthroughSubject<Event, Never>) {
+        self.eventsSubject = eventsSubject
+
         $text.map { !$0.isEmpty }
             .removeDuplicates()
             .combineLatest($attachmentViewModels.map { !$0.isEmpty })
@@ -45,7 +48,7 @@ public final class CompositionViewModel: AttachmentsRenderingViewModel, Observab
     }
 
     public func attachmentSelected(viewModel: AttachmentViewModel) {
-        
+        eventsSubject.send(.editAttachment(viewModel, self))
     }
 
     public func removeAttachment(viewModel: AttachmentViewModel) {
@@ -56,14 +59,13 @@ public final class CompositionViewModel: AttachmentsRenderingViewModel, Observab
 public extension CompositionViewModel {
     static let maxCharacters = 500
 
-    typealias Id = UUID
-
     enum Event {
-        case insertAfter(CompositionViewModel)
+        case editAttachment(AttachmentViewModel, CompositionViewModel)
-        case presentMediaPicker(CompositionViewModel)
+        case updateAttachment(AnyPublisher<Never, Error>)
-        case error(Error)
     }
 
+    typealias Id = UUID
+
     func components(inReplyToId: Status.Id?, visibility: Status.Visibility) -> StatusComponents {
         StatusComponents(
             inReplyToId: inReplyToId,
@@ -76,6 +78,23 @@ public extension CompositionViewModel {
     func cancelUpload() {
         attachmentUploadCancellable?.cancel()
     }
+
+    func update(attachmentViewModel: AttachmentViewModel) {
+        let publisher = attachmentViewModel.updated()
+            .receive(on: DispatchQueue.main)
+            .handleEvents(receiveOutput: { [weak self] updatedAttachmentViewModel in
+                guard let self = self,
+                      let index = self.attachmentViewModels.firstIndex(
+                        where: { $0.attachment.id == updatedAttachmentViewModel.attachment.id })
+                else { return }
+
+                self.attachmentViewModels[index] = updatedAttachmentViewModel
+            })
+            .ignoreOutput()
+            .eraseToAnyPublisher()
+
+        eventsSubject.send(.updateAttachment(publisher))
+    }
 }
 
 extension CompositionViewModel {

ViewModels/Sources/ViewModels/NewStatusViewModel.swift

@@ -7,7 +7,7 @@ import ServiceLayer
 
 public final class NewStatusViewModel: ObservableObject {
     @Published public var visibility: Status.Visibility
-    @Published public private(set) var compositionViewModels = [CompositionViewModel()]
+    @Published public private(set) var compositionViewModels: [CompositionViewModel]
     @Published public private(set) var identification: Identification
     @Published public private(set) var authenticatedIdentities = [Identity]()
     @Published public var canPost = false
@@ -19,7 +19,7 @@ public final class NewStatusViewModel: ObservableObject {
     private let allIdentitiesService: AllIdentitiesService
     private let environment: AppEnvironment
     private let eventsSubject = PassthroughSubject<Event, Never>()
-    private let itemEventsSubject = PassthroughSubject<CompositionViewModel.Event, Never>()
+    private let compositionEventsSubject = PassthroughSubject<CompositionViewModel.Event, Never>()
     private var cancellables = Set<AnyCancellable>()
 
     public init(allIdentitiesService: AllIdentitiesService,
@@ -28,6 +28,7 @@ public final class NewStatusViewModel: ObservableObject {
         self.allIdentitiesService = allIdentitiesService
         self.identification = identification
         self.environment = environment
+        compositionViewModels = [CompositionViewModel(eventsSubject: compositionEventsSubject)]
         events = eventsSubject.eraseToAnyPublisher()
         visibility = identification.identity.preferences.postingDefaultVisibility
         allIdentitiesService.authenticatedIdentitiesPublisher()
@@ -39,6 +40,9 @@ public final class NewStatusViewModel: ObservableObject {
             .combineLatest($postingState)
             .map { $0 && $1 == .composing }
             .assign(to: &$canPost)
+        compositionEventsSubject
+            .sink { [weak self] in self?.handle(event: $0) }
+            .store(in: &cancellables)
     }
 }
 
@@ -46,6 +50,7 @@ public extension NewStatusViewModel {
     enum Event {
         case presentMediaPicker(CompositionViewModel)
         case presentCamera(CompositionViewModel)
+        case editAttachment(AttachmentViewModel, CompositionViewModel)
     }
 
     enum PostingState {
@@ -85,7 +90,7 @@ public extension NewStatusViewModel {
         guard let index = compositionViewModels.firstIndex(where: { $0 === after })
         else { return }
 
-        let newViewModel = CompositionViewModel()
+        let newViewModel = CompositionViewModel(eventsSubject: compositionEventsSubject)
 
         newViewModel.contentWarning = after.contentWarning
         newViewModel.displayContentWarning = after.displayContentWarning
@@ -109,6 +114,14 @@ public extension NewStatusViewModel {
 }
 
 private extension NewStatusViewModel {
+    func handle(event: CompositionViewModel.Event) {
+        switch event {
+        case let .editAttachment(attachmentViewModel, compositionViewModel):
+            eventsSubject.send(.editAttachment(attachmentViewModel, compositionViewModel))
+        case let .updateAttachment(publisher):
+            publisher.assignErrorsToAlertItem(to: \.alertItem, on: self).sink { _ in }.store(in: &cancellables)
+        }
+    }
     func post(viewModel: CompositionViewModel, inReplyToId: Status.Id?) {
         postingState = .posting
         identification.service.post(statusComponents: viewModel.components(

Views/AttachmentView.swift

@@ -47,29 +47,13 @@ final class AttachmentView: UIView {
         super.layoutSubviews()
 
         if let focus = viewModel.attachment.meta?.focus {
-            let viewsAndSizes: [(UIView, CGSize?)] = [
+            let viewsAndMediaSizes: [(UIView, CGSize?)] = [
                 (imageView, imageView.image?.size),
                 (playerView, playerView.player?.currentItem?.presentationSize)]
-            for (view, size) in viewsAndSizes {
+            for (view, mediaSize) in viewsAndMediaSizes {
-                guard let size = size else { continue }
+                guard let size = mediaSize else { continue }
 
-                let aspectRatio = size.width / size.height
+                view.setContentsRect(focus: focus, mediaSize: size)
-                let viewAspectRatio = view.frame.width / view.frame.height
-                var origin = CGPoint.zero
-
-                if viewAspectRatio > aspectRatio {
-                    let mediaProportionalHeight = size.height * view.frame.width / size.width
-                    let maxPan = (mediaProportionalHeight - view.frame.height) / (2 * mediaProportionalHeight)
-
-                    origin.y = CGFloat(-focus.y) * maxPan
-                } else {
-                    let mediaProportionalWidth = size.width * view.frame.height / size.height
-                    let maxPan = (mediaProportionalWidth - view.frame.width) / (2 * mediaProportionalWidth)
-
-                    origin.x = CGFloat(focus.x) * maxPan
-                }
-
-                view.layer.contentsRect = .init(origin: origin, size: CGRect.defaultContentsRect.size)
             }
         }
     }

Views/EditAttachmentView.swift

@@ -0,0 +1,18 @@
+// Copyright © 2021 Metabolist. All rights reserved.
+
+import SwiftUI
+import ViewModels
+
+struct EditAttachmentView: UIViewControllerRepresentable {
+    let viewModelsClosure: () -> (AttachmentViewModel, CompositionViewModel)
+
+    func makeUIViewController(context: Context) -> EditAttachmentViewController {
+        let (attachmentViewModel, compositionViewModel) = viewModelsClosure()
+
+        return EditAttachmentViewController(viewModel: attachmentViewModel, parentViewModel: compositionViewModel)
+    }
+
+    func updateUIViewController(_ uiViewController: EditAttachmentViewController, context: Context) {
+
+    }
+}

Views/EditThumbnailView.swift

@@ -0,0 +1,218 @@
+// Copyright © 2021 Metabolist. All rights reserved.
+
+import Combine
+import Kingfisher
+import UIKit
+import ViewModels
+
+final class EditThumbnailView: UIView {
+    let playerView = PlayerView()
+    let imageView = UIImageView()
+    let previewImageView = UIImageView()
+    let promptBackgroundView = UIVisualEffectView(effect: UIBlurEffect(style: .systemChromeMaterial))
+    let thumbnailPromptLabel = UILabel()
+
+    private let viewModel: AttachmentViewModel
+    private var cancellables = Set<AnyCancellable>()
+
+    private lazy var circleView: UIVisualEffectView = {
+        let blurEffect = UIBlurEffect(style: .systemUltraThinMaterial)
+        let circleView = UIVisualEffectView(effect: blurEffect)
+        let vibrancyView = UIVisualEffectView(effect: UIVibrancyEffect(blurEffect: blurEffect))
+        let scopeImageView = UIImageView(
+            image: UIImage(systemName: "scope",
+                           withConfiguration: UIImage.SymbolConfiguration(scale: .medium)))
+
+        circleView.translatesAutoresizingMaskIntoConstraints = false
+        vibrancyView.translatesAutoresizingMaskIntoConstraints = false
+        scopeImageView.translatesAutoresizingMaskIntoConstraints = false
+        vibrancyView.contentView.addSubview(scopeImageView)
+        circleView.contentView.addSubview(vibrancyView)
+        circleView.layer.cornerRadius = .minimumButtonDimension / 2
+        circleView.clipsToBounds = true
+        scopeImageView.contentMode = .scaleAspectFit
+
+        NSLayoutConstraint.activate([
+            scopeImageView.centerXAnchor.constraint(equalTo: circleView.contentView.centerXAnchor),
+            scopeImageView.centerYAnchor.constraint(equalTo: circleView.contentView.centerYAnchor),
+            vibrancyView.leadingAnchor.constraint(equalTo: circleView.leadingAnchor),
+            vibrancyView.topAnchor.constraint(equalTo: circleView.topAnchor),
+            vibrancyView.trailingAnchor.constraint(equalTo: circleView.trailingAnchor),
+            vibrancyView.bottomAnchor.constraint(equalTo: circleView.bottomAnchor),
+            circleView.trailingAnchor.constraint(
+                equalTo: scopeImageView.trailingAnchor, constant: .compactSpacing),
+            circleView.bottomAnchor.constraint(
+                equalTo: scopeImageView.bottomAnchor, constant: .compactSpacing),
+            scopeImageView.topAnchor.constraint(
+                equalTo: circleView.topAnchor, constant: .compactSpacing),
+            scopeImageView.leadingAnchor.constraint(
+                equalTo: circleView.leadingAnchor, constant: .compactSpacing),
+            circleView.widthAnchor.constraint(equalToConstant: .minimumButtonDimension),
+            circleView.heightAnchor.constraint(equalToConstant: .minimumButtonDimension)
+        ])
+
+        return circleView
+    }()
+
+    init(viewModel: AttachmentViewModel) {
+        self.viewModel = viewModel
+
+        super.init(frame: .zero)
+
+        initialSetup()
+    }
+
+    @available(*, unavailable)
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+
+    override func touchesMoved(_ touches: Set<UITouch>, with event: UIEvent?) {
+        super.touchesMoved(touches, with: event)
+
+        guard let touch = touches.first else { return }
+
+        if promptBackgroundView.effect != nil {
+            UIView.animate(withDuration: .defaultAnimationDuration) {
+                self.promptBackgroundView.effect = nil
+                self.thumbnailPromptLabel.alpha = 0
+            }
+        }
+
+        let location = touch.location(in: self)
+
+        viewModel.editingFocus.x = Double(max(min(((location.x - (bounds.width / 2)) / (bounds.width / 2)), 1), -1))
+        viewModel.editingFocus.y = Double(max(min((-location.y / (bounds.height / 2)) + 1, 1), -1))
+    }
+}
+
+private extension EditThumbnailView {
+    // swiftlint:disable:next function_body_length
+    func initialSetup() {
+        backgroundColor = .secondarySystemBackground
+
+        addSubview(imageView)
+        imageView.translatesAutoresizingMaskIntoConstraints = false
+        imageView.contentMode = .scaleAspectFit
+        imageView.kf.indicatorType = .activity
+
+        addSubview(playerView)
+        playerView.translatesAutoresizingMaskIntoConstraints = false
+
+        addSubview(circleView)
+
+        let circleViewCenterXConstraint = circleView.centerXAnchor.constraint(equalTo: centerXAnchor)
+        let circleViewCenterYConstraint = circleView.centerYAnchor.constraint(equalTo: centerYAnchor)
+
+        addSubview(promptBackgroundView)
+        promptBackgroundView.translatesAutoresizingMaskIntoConstraints = false
+
+        if viewModel.editingFocus != .default {
+            promptBackgroundView.effect = nil
+        }
+
+        promptBackgroundView.contentView.addSubview(thumbnailPromptLabel)
+        thumbnailPromptLabel.translatesAutoresizingMaskIntoConstraints = false
+        thumbnailPromptLabel.adjustsFontForContentSizeCategory = true
+        thumbnailPromptLabel.font = .preferredFont(forTextStyle: .caption1)
+        thumbnailPromptLabel.numberOfLines = 0
+        thumbnailPromptLabel.textAlignment = .center
+        thumbnailPromptLabel.text = NSLocalizedString("attachment.edit.thumbnail.prompt", comment: "")
+
+        if viewModel.editingFocus != .default {
+            thumbnailPromptLabel.alpha = 0
+        }
+
+        let previewImageContainerView = UIView()
+
+        addSubview(previewImageContainerView)
+        previewImageContainerView.translatesAutoresizingMaskIntoConstraints = false
+        previewImageContainerView.layer.cornerRadius = .defaultCornerRadius
+        previewImageContainerView.layer.shadowOffset = .zero
+        previewImageContainerView.layer.shadowRadius = .defaultShadowRadius
+        previewImageContainerView.layer.shadowOpacity = 0.25
+
+        previewImageContainerView.addSubview(previewImageView)
+        previewImageView.translatesAutoresizingMaskIntoConstraints = false
+        previewImageView.contentMode = .scaleAspectFill
+        previewImageView.clipsToBounds = true
+        previewImageView.layer.cornerRadius = .defaultCornerRadius
+        previewImageView.kf.setImage(with: viewModel.attachment.previewUrl)
+
+        switch viewModel.attachment.type {
+        case .image:
+            playerView.isHidden = true
+            imageView.kf.setImage(
+                with: viewModel.attachment.previewUrl,
+                options: [.onlyFromCache],
+                completionHandler: { [weak self] in
+                    guard let self = self else { return }
+
+                    if case .success = $0 {
+                        self.imageView.kf.indicatorType = .none
+                    }
+
+                    self.imageView.kf.setImage(
+                        with: self.viewModel.attachment.url,
+                        options: [.keepCurrentImageWhileLoading])
+                })
+        case .gifv:
+            imageView.isHidden = true
+            let player = PlayerCache.shared.player(url: viewModel.attachment.url)
+
+            player.isMuted = true
+
+            playerView.player = player
+            player.play()
+        default: break
+        }
+
+        NSLayoutConstraint.activate([
+            imageView.leadingAnchor.constraint(equalTo: leadingAnchor),
+            imageView.trailingAnchor.constraint(equalTo: trailingAnchor),
+            imageView.topAnchor.constraint(equalTo: topAnchor),
+            imageView.bottomAnchor.constraint(equalTo: bottomAnchor),
+            playerView.leadingAnchor.constraint(equalTo: leadingAnchor),
+            playerView.trailingAnchor.constraint(equalTo: trailingAnchor),
+            playerView.topAnchor.constraint(equalTo: topAnchor),
+            playerView.bottomAnchor.constraint(equalTo: bottomAnchor),
+            circleViewCenterXConstraint,
+            circleViewCenterYConstraint,
+            promptBackgroundView.leadingAnchor.constraint(equalTo: leadingAnchor),
+            promptBackgroundView.topAnchor.constraint(equalTo: topAnchor),
+            promptBackgroundView.trailingAnchor.constraint(equalTo: trailingAnchor),
+            thumbnailPromptLabel.leadingAnchor.constraint(
+                equalTo: promptBackgroundView.layoutMarginsGuide.leadingAnchor),
+            thumbnailPromptLabel.topAnchor.constraint(equalTo: promptBackgroundView.layoutMarginsGuide.topAnchor),
+            thumbnailPromptLabel.trailingAnchor.constraint(
+                equalTo: promptBackgroundView.layoutMarginsGuide.trailingAnchor),
+            thumbnailPromptLabel.bottomAnchor.constraint(equalTo: promptBackgroundView.layoutMarginsGuide.bottomAnchor),
+            previewImageView.leadingAnchor.constraint(equalTo: previewImageContainerView.leadingAnchor),
+            previewImageView.topAnchor.constraint(equalTo: previewImageContainerView.topAnchor),
+            previewImageView.trailingAnchor.constraint(equalTo: previewImageContainerView.trailingAnchor),
+            previewImageView.bottomAnchor.constraint(equalTo: previewImageContainerView.bottomAnchor),
+            previewImageContainerView.trailingAnchor.constraint(equalTo: layoutMarginsGuide.trailingAnchor),
+            previewImageContainerView.bottomAnchor.constraint(
+                equalTo: layoutMarginsGuide.bottomAnchor,
+                constant: -.defaultSpacing),
+            previewImageContainerView.widthAnchor.constraint(
+                equalTo: previewImageContainerView.heightAnchor,
+                multiplier: 16 / 9),
+            previewImageContainerView.heightAnchor.constraint(equalTo: heightAnchor, multiplier: 1 / 8)
+        ])
+
+        viewModel.$editingFocus
+            .receive(on: DispatchQueue.main) // punt to next run loop to allow initial layout to happen
+            .sink { [weak self] in
+                guard let self = self else { return }
+
+                circleViewCenterXConstraint.constant = CGFloat($0.x) * self.bounds.width / 2
+                circleViewCenterYConstraint.constant = -CGFloat($0.y) * self.bounds.height / 2
+
+                guard let mediaSize = self.previewImageView.image?.size else { return }
+
+                self.previewImageView.setContentsRect(focus: $0, mediaSize: mediaSize)
+            }
+            .store(in: &cancellables)
+    }
+}

Views/TabNavigationView.swift

@@ -181,7 +181,7 @@ private extension TabNavigationView {
                 .clipShape(Circle())
                 .frame(width: .newStatusButtonDimension,
                        height: .newStatusButtonDimension)
-                .shadow(radius: .newStatusButtonShadowRadius)
+                .shadow(radius: .defaultShadowRadius)
                 .padding()
             }
         }

Views/ViewConstants.swift

@@ -12,7 +12,7 @@ extension CGFloat {
     static let minimumButtonDimension: Self = 44
     static let barButtonItemDimension: Self = 28
     static let newStatusButtonDimension: CGFloat = 54
-    static let newStatusButtonShadowRadius: CGFloat = 2
+    static let defaultShadowRadius: CGFloat = 2
 }
 
 extension CGRect {