New items indicator

Localizations/Localizable.strings

@@ -160,6 +160,7 @@
 "main-navigation.conversations" = "Messages";
 "metatext" = "Metatext";
 "notification.signed-in-as-%@" = "Logged in as %@";
+"notification.new-items" = "New notifications";
 "notifications.all" = "All";
 "notifications.mentions" = "Mentions";
 "ok" = "OK";
@@ -274,6 +275,8 @@
 "status.delete-and-redraft.confirm.post" = "Are you sure you want to delete this post and re-draft it? Favorites and boosts will be lost, and replies to the original post will be orphaned.";
 "status.delete-and-redraft.confirm.toot" = "Are you sure you want to delete this toot and re-draft it? Favorites and boosts will be lost, and replies to the original toot will be orphaned.";
 "status.mute" = "Mute conversation";
+"status.new-items.post" = "New posts";
+"status.new-items.toot" = "New toots";
 "status.pin" = "Pin on profile";
 "status.pinned.post" = "Pinned post";
 "status.pinned.toot" = "Pinned toot";

Metatext.xcodeproj/project.pbxproj

@@ -160,6 +160,7 @@
 		D0C7D4DA24F7616A001EBDBB /* View+Extensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0C7D46F24F76169001EBDBB /* View+Extensions.swift */; };
 		D0CE9F87258B076900E3A6B6 /* AttachmentUploadView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0CE9F86258B076900E3A6B6 /* AttachmentUploadView.swift */; };
 		D0CE9F88258B076900E3A6B6 /* AttachmentUploadView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0CE9F86258B076900E3A6B6 /* AttachmentUploadView.swift */; };
+		D0CEC0E125E0BB9700FEF5A6 /* NewItemsView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0CEC0E025E0BB9700FEF5A6 /* NewItemsView.swift */; };
 		D0D2AC3925BBEC0F003D5DF2 /* CollectionSection+Extensions.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0D2AC3825BBEC0F003D5DF2 /* CollectionSection+Extensions.swift */; };
 		D0D2AC4725BCD289003D5DF2 /* TagView.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0D2AC4625BCD289003D5DF2 /* TagView.swift */; };
 		D0D2AC4D25BCD2A9003D5DF2 /* TagTableViewCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = D0D2AC4C25BCD2A9003D5DF2 /* TagTableViewCell.swift */; };
@@ -376,6 +377,7 @@
 		D0C7D46C24F76169001EBDBB /* UIColor+Extensions.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "UIColor+Extensions.swift"; sourceTree = "<group>"; };
 		D0C7D46F24F76169001EBDBB /* View+Extensions.swift */ = {isa = PBXFileReference; fileEncoding = 4; lastKnownFileType = sourcecode.swift; path = "View+Extensions.swift"; sourceTree = "<group>"; };
 		D0CE9F86258B076900E3A6B6 /* AttachmentUploadView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = AttachmentUploadView.swift; sourceTree = "<group>"; };
+		D0CEC0E025E0BB9700FEF5A6 /* NewItemsView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = NewItemsView.swift; sourceTree = "<group>"; };
 		D0D2AC3825BBEC0F003D5DF2 /* CollectionSection+Extensions.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "CollectionSection+Extensions.swift"; sourceTree = "<group>"; };
 		D0D2AC4625BCD289003D5DF2 /* TagView.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TagView.swift; sourceTree = "<group>"; };
 		D0D2AC4C25BCD2A9003D5DF2 /* TagTableViewCell.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = TagTableViewCell.swift; sourceTree = "<group>"; };
@@ -463,6 +465,7 @@
 				D0CE9F86258B076900E3A6B6 /* AttachmentUploadView.swift */,
 				D0BEB1F224F8EE8C001B0F04 /* AttachmentView.swift */,
 				D025B17D25C500BC001C69A8 /* CapsuleButton.swift */,
+				D0477F4525C72E50005C5368 /* CapsuleLabel.swift */,
 				D0EA593F2522AC8700804347 /* CardView.swift */,
 				D021A66F25C3E1F9008A0C0D /* Collection View Cells */,
 				D0E9F9A9258450B300EF503D /* CompositionInputAccessoryView.swift */,
@@ -475,11 +478,11 @@
 				D05936DD25A937EC00754FDF /* EditThumbnailView.swift */,
 				D07EC7FC25B16994006DF726 /* EmojiCategoryHeaderView.swift */,
 				D0DDA77E25C6058300FA0F91 /* ExploreSectionHeaderView.swift */,
-				D0477F4525C72E50005C5368 /* CapsuleLabel.swift */,
 				D0BE97D625D0863E0057E161 /* ImagePastableTextView.swift */,
 				D0D2AC6625BD0484003D5DF2 /* LineChartView.swift */,
 				D0BEB1F624F9A84B001B0F04 /* LoadingTableFooterView.swift */,
 				D05936FE25AA94EA00754FDF /* MarkAttachmentsSensitiveView.swift */,
+				D0CEC0E025E0BB9700FEF5A6 /* NewItemsView.swift */,
 				D035F8A825B9155900DC75ED /* NewStatusButtonView.swift */,
 				D0FE1C8E253686F9003EF1EB /* PlayerView.swift */,
 				D08B8D812544D80000B1EBEF /* PollOptionButton.swift */,
@@ -1138,6 +1141,7 @@
 				D0C7D4C324F7616A001EBDBB /* MetatextApp.swift in Sources */,
 				D097F4C125BFA04C00859F2C /* NotificationsViewController.swift in Sources */,
 				D0E1F583251F13EC00D45315 /* WebfingerIndicatorView.swift in Sources */,
+				D0CEC0E125E0BB9700FEF5A6 /* NewItemsView.swift in Sources */,
 				D0BEB20524FA1107001B0F04 /* FiltersView.swift in Sources */,
 				D0DDA76B25C5F20800FA0F91 /* ExploreDataSource.swift in Sources */,
 				D0477F4625C72E50005C5368 /* CapsuleLabel.swift in Sources */,

ServiceLayer/Sources/ServiceLayer/Services/CollectionService.swift

@@ -11,6 +11,7 @@ public protocol CollectionService {
     var canRefresh: Bool { get }
     var title: AnyPublisher<String, Never> { get }
     var titleLocalizationComponents: AnyPublisher<[String], Never> { get }
+    var announcesNewItems: Bool { get }
     var navigationService: NavigationService { get }
     var positionTimeline: Timeline? { get }
     func request(maxId: String?, minId: String?, search: Search?) -> AnyPublisher<Never, Error>
@@ -31,6 +32,8 @@ extension CollectionService {
 
     public var titleLocalizationComponents: AnyPublisher<[String], Never> { Empty().eraseToAnyPublisher() }
 
+    public var announcesNewItems: Bool { false }
+
     public var positionTimeline: Timeline? { nil }
 
     public func requestMarkerLastReadId() -> AnyPublisher<CollectionItem.Id, Error> { Empty().eraseToAnyPublisher() }

ServiceLayer/Sources/ServiceLayer/Services/NotificationsService.swift

@@ -10,6 +10,7 @@ public struct NotificationsService {
     public let sections: AnyPublisher<[CollectionSection], Error>
     public let nextPageMaxId: AnyPublisher<String, Never>
     public let navigationService: NavigationService
+    public let announcesNewItems = true
 
     private let excludeTypes: Set<MastodonNotification.NotificationType>
     private let mastodonAPIClient: MastodonAPIClient

ServiceLayer/Sources/ServiceLayer/Services/TimelineService.swift

@@ -13,6 +13,7 @@ public struct TimelineService {
     public let accountIdsForRelationships: AnyPublisher<Set<Account.Id>, Never>
     public let title: AnyPublisher<String, Never>
     public let titleLocalizationComponents: AnyPublisher<[String], Never>
+    public let announcesNewItems = true
 
     private let timeline: Timeline
     private let mastodonAPIClient: MastodonAPIClient

View Controllers/TableViewController.swift

@@ -16,11 +16,14 @@ class TableViewController: UITableViewController {
     private let rootViewModel: RootViewModel?
     private let loadingTableFooterView = LoadingTableFooterView()
     private let webfingerIndicatorView = WebfingerIndicatorView()
+    private let newItemsView = NewItemsView()
     @Published private var loading = false
     private var visibleLoadMoreViews = Set<LoadMoreView>()
     private var cancellables = Set<AnyCancellable>()
     private var cellHeightCaches = [CGFloat: [CollectionItem: CGFloat]]()
     private var shouldKeepPlayingVideoAfterDismissal = false
+    private var newItemsViewHiddenConstraint: NSLayoutConstraint?
+    private var newItemsViewVisibleConstraint: NSLayoutConstraint?
     private let insetBottom: Bool
     private weak var parentNavigationController: UINavigationController?
 
@@ -67,11 +70,27 @@ class TableViewController: UITableViewController {
         view.addSubview(webfingerIndicatorView)
         webfingerIndicatorView.translatesAutoresizingMaskIntoConstraints = false
 
+        view.addSubview(newItemsView)
+        newItemsView.translatesAutoresizingMaskIntoConstraints = false
+        newItemsView.alpha = 0
+
+        newItemsViewHiddenConstraint = newItemsView.bottomAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor)
+        newItemsViewHiddenConstraint?.isActive = true
+        newItemsViewVisibleConstraint = newItemsView.topAnchor.constraint(equalTo: view.safeAreaLayoutGuide.topAnchor,
+                                                                          constant: .defaultSpacing)
+
         NSLayoutConstraint.activate([
             webfingerIndicatorView.centerXAnchor.constraint(equalTo: view.safeAreaLayoutGuide.centerXAnchor),
-            webfingerIndicatorView.centerYAnchor.constraint(equalTo: view.safeAreaLayoutGuide.centerYAnchor)
+            webfingerIndicatorView.centerYAnchor.constraint(equalTo: view.safeAreaLayoutGuide.centerYAnchor),
+            newItemsView.centerXAnchor.constraint(equalTo: view.safeAreaLayoutGuide.centerXAnchor)
         ])
 
+        newItemsView.button.addAction(UIAction { [weak self] _ in
+            self?.newItemsTapped()
+            self?.hideNewItemsView()
+        },
+        for: .touchUpInside)
+
         setupViewModelBindings()
 
         viewModel.request(maxId: nil, minId: nil, search: nil)
@@ -91,6 +110,10 @@ class TableViewController: UITableViewController {
         for loadMoreView in visibleLoadMoreViews {
             loadMoreView.directionChanged(up: up)
         }
+
+        if up, newItemsView.alpha > 0 {
+            hideNewItemsView()
+        }
     }
 
     override func scrollViewDidEndDragging(_ scrollView: UIScrollView, willDecelerate decelerate: Bool) {
@@ -313,7 +336,9 @@ extension TableViewController: ZoomAnimatorDelegate {
 
 extension TableViewController: ScrollableToTop {
     func scrollToTop(animated: Bool) {
-        tableView.scrollToTop(animated: animated)
+        guard !dataSource.snapshot().itemIdentifiers.isEmpty else { return }
+
+        tableView.scrollToRow(at: IndexPath(row: 0, section: 0), at: .top, animated: true)
     }
 }
 
@@ -401,6 +426,7 @@ private extension TableViewController {
         let positionMaintenanceOffset: CGFloat
         let preUpdateContentOffsetY = tableView.contentOffset.y
         var setPreviousOffset = false
+        let firstItemId = dataSource.snapshot().itemIdentifiers.first?.itemId
 
         if let itemId = update.maintainScrollPositionItemId,
            let indexPath = dataSource.indexPath(itemId: itemId) {
@@ -430,6 +456,16 @@ private extension TableViewController {
 
                 self.tableView.scrollToRow(at: indexPath, at: .top, animated: false)
                 self.tableView.contentOffset.y -= positionMaintenanceOffset
+
+                if self.viewModel.announcesNewItems,
+                   let firstItemId = firstItemId,
+                   let newFirstItem = self.dataSource.snapshot().itemIdentifiers.first,
+                   let newFirstItemId = newFirstItem.itemId,
+                   newFirstItemId > firstItemId {
+                    DispatchQueue.main.async {
+                        self.announceNewItems(newestItem: newFirstItem)
+                    }
+                }
             } else if setPreviousOffset {
                 self.tableView.contentOffset.y = preUpdateContentOffsetY
             }
@@ -723,5 +759,49 @@ private extension TableViewController {
             viewModel.request(maxId: nil, minId: nil, search: nil)
         }
     }
+
+    func newItemsTapped() {
+        scrollToTop(animated: true)
+    }
+
+    func announceNewItems(newestItem: CollectionItem) {
+        switch newestItem {
+        case .status:
+            switch viewModel.identityContext.appPreferences.statusWord {
+            case .toot:
+                newItemsView.title = NSLocalizedString("status.new-items.toot", comment: "")
+            case .post:
+                newItemsView.title = NSLocalizedString("status.new-items.post", comment: "")
+            }
+        case .notification:
+            newItemsView.title = NSLocalizedString("notification.new-items", comment: "")
+        default:
+            return
+        }
+
+        newItemsView.layoutIfNeeded()
+
+        UIView.animate(withDuration: .zeroIfReduceMotion(.defaultAnimationDuration),
+                       delay: 0,
+                       usingSpringWithDamping: 0.5,
+                       initialSpringVelocity: 5,
+                       options: .curveEaseInOut) {
+            self.newItemsView.alpha = 1
+            self.newItemsViewHiddenConstraint?.isActive = false
+            self.newItemsViewVisibleConstraint?.isActive = true
+            self.view.layoutIfNeeded()
+        } completion: { _ in
+
+        }
+    }
+
+    func hideNewItemsView() {
+        UIView.animate(withDuration: .zeroIfReduceMotion(.defaultAnimationDuration)) {
+            self.newItemsView.alpha = 0
+            self.newItemsViewHiddenConstraint?.isActive = true
+            self.newItemsViewVisibleConstraint?.isActive = false
+            self.view.layoutIfNeeded()
+        }
+    }
 }
 // swiftlint:enable file_length

ViewModels/Sources/ViewModels/View Models/CollectionItemsViewModel.swift

@@ -125,6 +125,8 @@ extension CollectionItemsViewModel: CollectionViewModel {
 
     public var canRefresh: Bool { collectionService.canRefresh }
 
+    public var announcesNewItems: Bool { collectionService.announcesNewItems }
+
     public func request(maxId: String? = nil, minId: String? = nil, search: Search?) {
         collectionService.request(maxId: realMaxId(maxId: maxId), minId: minId, search: search)
             .receive(on: DispatchQueue.main)
@@ -409,7 +411,7 @@ private extension CollectionItemsViewModel {
             return configuration.isContextParent // Maintain scroll position of parent after initial load of context
            }) {
             return contextParent.itemId
-        } else if collectionService is TimelineService {
+        } else if collectionService is TimelineService || collectionService is NotificationsService {
             let difference = newItems.difference(from: items)
 
             if let lastSelectedLoadMore = lastSelectedLoadMore {

ViewModels/Sources/ViewModels/View Models/CollectionViewModel.swift

@@ -15,6 +15,7 @@ public protocol CollectionViewModel {
     var searchScopeChanges: AnyPublisher<SearchScope, Never> { get }
     var nextPageMaxId: String? { get }
     var canRefresh: Bool { get }
+    var announcesNewItems: Bool { get }
     func request(maxId: String?, minId: String?, search: Search?)
     func requestNextPage(fromIndexPath indexPath: IndexPath)
     func viewedAtTop(indexPath: IndexPath)

ViewModels/Sources/ViewModels/View Models/NavigationViewModel.swift

@@ -167,7 +167,9 @@ public extension NavigationViewModel {
             collectionService: identityContext.service.notificationsService(excludeTypes: excludeTypes),
             identityContext: identityContext)
 
+        if excludeTypes.isEmpty {
             viewModel.request(maxId: nil, minId: nil, search: nil)
+        }
 
         return viewModel
     }

ViewModels/Sources/ViewModels/View Models/ProfileViewModel.swift

@@ -139,6 +139,8 @@ extension ProfileViewModel: CollectionViewModel {
 
     public var canRefresh: Bool { collectionViewModel.value.canRefresh }
 
+    public var announcesNewItems: Bool { collectionViewModel.value.canRefresh }
+
     public func request(maxId: String?, minId: String?, search: Search?) {
         if case .statuses = collection, maxId == nil {
             profileService.fetchPinnedStatuses()

Views/UIKit/NewItemsView.swift

@@ -0,0 +1,110 @@
+// Copyright © 2021 Metabolist. All rights reserved.
+
+import UIKit
+
+final class NewItemsView: UIView {
+    let button = UIButton()
+
+    public var title: String? {
+        get { label.text }
+        set {
+            label.text = newValue
+            button.accessibilityLabel = newValue
+        }
+    }
+
+    private let label = UILabel()
+    private let blurView: UIVisualEffectView
+    private let vibrancyView: UIVisualEffectView
+
+    init() {
+        let blurEffect = UIBlurEffect(style: .systemChromeMaterial)
+        blurView = UIVisualEffectView(effect: blurEffect)
+        vibrancyView = UIVisualEffectView(effect: UIVibrancyEffect(blurEffect: blurEffect, style: .label))
+
+        super.init(frame: .zero)
+
+        initialSetup()
+    }
+
+    @available(*, unavailable)
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+
+    override func layoutSubviews() {
+        super.layoutSubviews()
+
+        let cornerRadius = bounds.height / 2
+
+        layer.cornerRadius = cornerRadius
+        blurView.layer.cornerRadius = cornerRadius
+    }
+}
+
+private extension NewItemsView {
+    // swiftlint:disable:next function_body_length
+    func initialSetup() {
+        backgroundColor = .clear
+        layer.shadowOffset = .zero
+        layer.shadowRadius = .defaultShadowRadius
+        layer.shadowOpacity = .defaultShadowOpacity
+
+        addSubview(blurView)
+        blurView.translatesAutoresizingMaskIntoConstraints = false
+        blurView.clipsToBounds = true
+        blurView.contentView.addSubview(vibrancyView)
+        vibrancyView.translatesAutoresizingMaskIntoConstraints = false
+
+        let stackView = UIStackView()
+
+        vibrancyView.contentView.addSubview(stackView)
+        stackView.translatesAutoresizingMaskIntoConstraints = false
+        stackView.spacing = .defaultSpacing
+
+        let arrowImage = UIImage(systemName: "arrow.up",
+                                 withConfiguration: UIImage.SymbolConfiguration(weight: .bold))
+
+        stackView.addArrangedSubview(UIImageView(image: arrowImage))
+        stackView.addArrangedSubview(label)
+        label.adjustsFontForContentSizeCategory = true
+        label.font = .preferredFont(forTextStyle: .headline)
+
+        addSubview(button)
+        button.translatesAutoresizingMaskIntoConstraints = false
+
+        let touchStartAction = UIAction { [weak self] _ in self?.alpha = 0.75 }
+
+        button.addAction(touchStartAction, for: .touchDown)
+        button.addAction(touchStartAction, for: .touchDragEnter)
+
+        let touchEndAction = UIAction { [weak self] _ in self?.alpha = 1 }
+
+        button.addAction(touchEndAction, for: .touchDragExit)
+        button.addAction(touchEndAction, for: .touchUpInside)
+        button.addAction(touchEndAction, for: .touchUpOutside)
+        button.addAction(touchEndAction, for: .touchCancel)
+
+        NSLayoutConstraint.activate([
+            blurView.leadingAnchor.constraint(equalTo: leadingAnchor),
+            blurView.topAnchor.constraint(equalTo: topAnchor),
+            blurView.trailingAnchor.constraint(equalTo: trailingAnchor),
+            blurView.bottomAnchor.constraint(equalTo: bottomAnchor),
+            button.leadingAnchor.constraint(equalTo: leadingAnchor),
+            button.topAnchor.constraint(equalTo: topAnchor),
+            button.trailingAnchor.constraint(equalTo: trailingAnchor),
+            button.bottomAnchor.constraint(equalTo: bottomAnchor),
+            vibrancyView.leadingAnchor.constraint(equalTo: blurView.contentView.leadingAnchor),
+            vibrancyView.topAnchor.constraint(equalTo: blurView.contentView.topAnchor),
+            vibrancyView.trailingAnchor.constraint(equalTo: blurView.contentView.trailingAnchor),
+            vibrancyView.bottomAnchor.constraint(equalTo: blurView.contentView.bottomAnchor),
+            stackView.leadingAnchor.constraint(equalTo: vibrancyView.contentView.leadingAnchor,
+                                               constant: .defaultSpacing),
+            stackView.topAnchor.constraint(equalTo: vibrancyView.contentView.topAnchor, constant: .defaultSpacing),
+            stackView.trailingAnchor.constraint(equalTo: vibrancyView.contentView.trailingAnchor,
+                                                constant: -.defaultSpacing * 2),
+            stackView.bottomAnchor.constraint(equalTo: vibrancyView.contentView.bottomAnchor,
+                                              constant: -.defaultSpacing)
+        ])
+    }
+}