Re-add public timeline descriptions

Tusker.xcodeproj/project.pbxproj

@@ -215,6 +215,7 @@
 		D6AC956723C4347E008C9946 /* MainSceneDelegate.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6AC956623C4347E008C9946 /* MainSceneDelegate.swift */; };
 		D6ACE1AC240C3BAD004EA8E2 /* Ambassador.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = D65F613023AE99E000F3CFD3 /* Ambassador.framework */; };
 		D6ACE1AD240C3BAD004EA8E2 /* Embassy.framework in Frameworks */ = {isa = PBXBuildFile; fileRef = D65F612D23AE990C00F3CFD3 /* Embassy.framework */; };
+		D6ADB6E828E8C878009924AB /* PublicTimelineDescriptionCollectionViewCell.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6ADB6E728E8C878009924AB /* PublicTimelineDescriptionCollectionViewCell.swift */; };
 		D6AEBB3E2321638100E5038B /* UIActivity+Types.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6AEBB3D2321638100E5038B /* UIActivity+Types.swift */; };
 		D6AEBB412321642700E5038B /* SendMesasgeActivity.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6AEBB402321642700E5038B /* SendMesasgeActivity.swift */; };
 		D6AEBB432321685E00E5038B /* OpenInSafariActivity.swift in Sources */ = {isa = PBXBuildFile; fileRef = D6AEBB422321685E00E5038B /* OpenInSafariActivity.swift */; };
@@ -560,6 +561,7 @@
 		D6A6C11425B62E9700298D0F /* CacheExpiry.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = CacheExpiry.swift; sourceTree = "<group>"; };
 		D6A6C11A25B63CEE00298D0F /* MemoryCache.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MemoryCache.swift; sourceTree = "<group>"; };
 		D6AC956623C4347E008C9946 /* MainSceneDelegate.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = MainSceneDelegate.swift; sourceTree = "<group>"; };
+		D6ADB6E728E8C878009924AB /* PublicTimelineDescriptionCollectionViewCell.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = PublicTimelineDescriptionCollectionViewCell.swift; sourceTree = "<group>"; };
 		D6AEBB3D2321638100E5038B /* UIActivity+Types.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = "UIActivity+Types.swift"; sourceTree = "<group>"; };
 		D6AEBB402321642700E5038B /* SendMesasgeActivity.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = SendMesasgeActivity.swift; sourceTree = "<group>"; };
 		D6AEBB422321685E00E5038B /* OpenInSafariActivity.swift */ = {isa = PBXFileReference; lastKnownFileType = sourcecode.swift; path = OpenInSafariActivity.swift; sourceTree = "<group>"; };
@@ -897,6 +899,7 @@
 				D6BC9DD6232D7811002CA326 /* TimelinesPageViewController.swift */,
 				D65234D225618EFA001AF9CF /* TimelineTableViewController.swift */,
 				D66C900A28DAB7FD00217BF2 /* TimelineViewController.swift */,
+				D6ADB6E728E8C878009924AB /* PublicTimelineDescriptionCollectionViewCell.swift */,
 			);
 			path = Timeline;
 			sourceTree = "<group>";
@@ -1889,6 +1892,7 @@
 				D61A45E628DC0F2F002BE511 /* ConfirmLoadMoreCollectionViewCell.swift in Sources */,
 				D663626C21361C6700C9CBA2 /* Account+Preferences.swift in Sources */,
 				D67895C0246870DE00D4CD9E /* LocalAccountAvatarView.swift in Sources */,
+				D6ADB6E828E8C878009924AB /* PublicTimelineDescriptionCollectionViewCell.swift in Sources */,
 				D6333B372137838300CE884A /* AttributedString+Helpers.swift in Sources */,
 				D622757824EE133700B82A16 /* ComposeAssetPicker.swift in Sources */,
 				D681A29A249AD62D0085E54E /* LargeImageContentView.swift in Sources */,

Tusker/Screens/Timeline/PublicTimelineDescriptionCollectionViewCell.swift

@@ -0,0 +1,62 @@
+//
+//  PublicTimelineDescriptionCollectionViewCell.swift
+//  Tusker
+//
+//  Created by Shadowfacts on 10/1/22.
+//  Copyright © 2022 Shadowfacts. All rights reserved.
+//
+
+import UIKit
+
+class PublicTimelineDescriptionCollectionViewCell: UICollectionViewCell {
+    
+    weak var mastodonController: MastodonController!
+    
+    var local = false {
+        didSet {
+            updateLabel()
+        }
+    }
+    var didDismiss: (() -> Void)?
+    
+    private let label = UILabel()
+    
+    override init(frame: CGRect) {
+        super.init(frame: frame)
+        
+        contentView.backgroundColor = .tintColor
+        label.font = .preferredFont(forTextStyle: .body)
+        label.numberOfLines = 0
+        label.textColor = .white
+        label.translatesAutoresizingMaskIntoConstraints = false
+        contentView.addSubview(label)
+        NSLayoutConstraint.activate([
+            label.leadingAnchor.constraint(equalToSystemSpacingAfter: contentView.leadingAnchor, multiplier: 1),
+            contentView.trailingAnchor.constraint(equalToSystemSpacingAfter: label.trailingAnchor, multiplier: 1),
+            label.topAnchor.constraint(equalToSystemSpacingBelow: contentView.topAnchor, multiplier: 1),
+            contentView.bottomAnchor.constraint(equalToSystemSpacingBelow: label.bottomAnchor, multiplier: 1),
+        ])
+    }
+    
+    required init?(coder: NSCoder) {
+        fatalError("init(coder:) has not been implemented")
+    }
+    
+    private func updateLabel() {
+        let str = NSMutableAttributedString()
+        let instanceStr = NSAttributedString(string: mastodonController.instanceURL.host!, attributes: [
+            .font: UIFont(descriptor: .preferredFontDescriptor(withTextStyle: .body).withSymbolicTraits(.traitBold)!, size: 0)
+        ])
+        if local {
+            str.append(NSAttributedString(string: "The local timeline shows public posts from only "))
+            str.append(instanceStr)
+            str.append(NSAttributedString(string: "."))
+        } else {
+            str.append(NSAttributedString(string: "The federated timeline shows public posts from all users that "))
+            str.append(instanceStr)
+            str.append(NSAttributedString(string: " knows about."))
+        }
+        label.attributedText = str
+    }
+    
+}

Tusker/Screens/Timeline/TimelineViewController.swift

@@ -22,6 +22,8 @@ class TimelineViewController: UIViewController, TimelineLikeCollectionViewContro
     let confirmLoadMore = PassthroughSubject<Void, Never>()
     private var newer: RequestRange?
     private var older: RequestRange?
+    // stored separately because i don't want to query the snapshot every time the user scrolls
+    private var isShowingTimelineDescription = false
     
     var collectionView: UICollectionView {
         view as! UICollectionView
@@ -63,6 +65,7 @@ class TimelineViewController: UIViewController, TimelineLikeCollectionViewContro
         //        collectionView.dragDelegate = self
         
         registerTimelineLikeCells()
+        collectionView.register(PublicTimelineDescriptionCollectionViewCell.self, forCellWithReuseIdentifier: "publicTimelineDescription")
         dataSource = createDataSource()
         applyInitialSnapshot()
         
@@ -94,6 +97,16 @@ class TimelineViewController: UIViewController, TimelineLikeCollectionViewContro
             config.text = try! doc.text()
             cell.contentConfiguration = config
         }
+        let timelineDescriptionCell = UICollectionView.CellRegistration<PublicTimelineDescriptionCollectionViewCell, Item> { [unowned self] cell, indexPath, item in
+            guard case .public(let local) = timeline else {
+                fatalError()
+            }
+            cell.mastodonController = self.mastodonController
+            cell.local = local
+            cell.didDismiss = { [unowned self] in
+                self.removeTimelineDescriptionCell()
+            }
+        }
         return UICollectionViewDiffableDataSource(collectionView: collectionView) { [unowned self] collectionView, indexPath, itemIdentifier in
             switch itemIdentifier {
             case .status(_, _):
@@ -102,13 +115,22 @@ class TimelineViewController: UIViewController, TimelineLikeCollectionViewContro
                 return loadingIndicatorCell(for: indexPath)
             case .confirmLoadMore:
                 return confirmLoadMoreCell(for: indexPath)
+            case .publicTimelineDescription:
+                self.isShowingTimelineDescription = true
+                return collectionView.dequeueConfiguredReusableCell(using: timelineDescriptionCell, for: indexPath, item: itemIdentifier)
             }
         }
     }
     
     private func applyInitialSnapshot() {
-        // TODO: this might not be necessary
+        if case .public(let local) = timeline,
-        // TODO: yes it is, for public timeline descriptions
+           (local && !Preferences.shared.hasShownLocalTimelineDescription) ||
+            (!local && Preferences.shared.hasShownFederatedTimelineDescription) {
+            var snapshot = dataSource.snapshot()
+            snapshot.appendSections([.header])
+            snapshot.appendItems([.publicTimelineDescription], toSection: .header)
+            dataSource.apply(snapshot, animatingDifferences: false)
+        }
     }
     
     override func viewWillAppear(_ animated: Bool) {
@@ -119,6 +141,13 @@ class TimelineViewController: UIViewController, TimelineLikeCollectionViewContro
         }
     }
     
+    private func removeTimelineDescriptionCell() {
+        var snapshot = dataSource.snapshot()
+        snapshot.deleteSections([.header])
+        dataSource.apply(snapshot, animatingDifferences: true)
+        isShowingTimelineDescription = false
+    }
+    
 }
 
 extension TimelineViewController {
@@ -135,8 +164,7 @@ extension TimelineViewController {
         case status(id: String, state: StatusState)
         case loadingIndicator
         case confirmLoadMore
-//        // TODO: remove local param from this
+        case publicTimelineDescription
-//        case publicTimelineDescription(local: Bool)
         
         static func fromTimelineItem(_ id: String) -> Self {
             return .status(id: id, state: .unknown)
@@ -150,8 +178,8 @@ extension TimelineViewController {
                 return true
             case (.confirmLoadMore, .confirmLoadMore):
                 return true
-//            case let (.publicTimelineDescription(local: a), .publicTimelineDescription(local: b)):
+            case (.publicTimelineDescription, .publicTimelineDescription):
-//                return a == b
+                return true
             default:
                 return false
             }
@@ -166,15 +194,14 @@ extension TimelineViewController {
                 hasher.combine(1)
             case .confirmLoadMore:
                 hasher.combine(2)
-//            case .publicTimelineDescription(local: let local):
+            case .publicTimelineDescription:
-//                hasher.combine(3)
+                hasher.combine(3)
-//                hasher.combine(local)
             }
         }
         
         var hideSeparators: Bool {
             switch self {
-            case .loadingIndicator:
+            case .loadingIndicator, .publicTimelineDescription:
                 return true
             default:
                 return false
@@ -192,8 +219,6 @@ extension TimelineViewController {
             throw Error.noClient
         }
         
-        try await Task.sleep(nanoseconds: 2 * NSEC_PER_SEC)
-        
         let request = Client.getStatuses(timeline: timeline)
         let (statuses, _) = try await mastodonController.run(request)
         
@@ -235,8 +260,6 @@ extension TimelineViewController {
             throw Error.noOlder
         }
         
-        try await Task.sleep(nanoseconds: 2 * NSEC_PER_SEC)
-        
         let request = Client.getStatuses(timeline: timeline, range: older)
         let (statuses, _) = try await mastodonController.run(request)
         
@@ -273,4 +296,24 @@ extension TimelineViewController: UICollectionViewDelegate {
             }
         }
     }
+    
+    func collectionView(_ collectionView: UICollectionView, didSelectItemAt indexPath: IndexPath) {
+        guard let item = dataSource.itemIdentifier(for: indexPath) else {
+            return
+        }
+        switch item {
+        case .publicTimelineDescription:
+            removeTimelineDescriptionCell()
+            
+        default:
+            // TODO: cell selection
+            break
+        }
+    }
+    
+    func scrollViewWillBeginDragging(_ scrollView: UIScrollView) {
+        if isShowingTimelineDescription {
+            removeTimelineDescriptionCell()
+        }
+    }
 }

Tusker/Screens/Timeline/TimelinesPageViewController.swift

@@ -22,10 +22,10 @@ class TimelinesPageViewController: SegmentedPageViewController {
         let home = TimelineViewController(for: .home, mastodonController: mastodonController)
         home.title = homeTitle
         
-        let federated = TimelineTableViewController(for: .public(local: false), mastodonController: mastodonController)
+        let federated = TimelineViewController(for: .public(local: false), mastodonController: mastodonController)
         federated.title = federatedTitle
         
-        let local = TimelineTableViewController(for: .public(local: true), mastodonController: mastodonController)
+        let local = TimelineViewController(for: .public(local: true), mastodonController: mastodonController)
         local.title = localTitle
         
         super.init(titles: [

Tusker/Screens/Utilities/TimelineLikeCollectionViewController.swift

@@ -52,7 +52,7 @@ extension TimelineLikeCollectionViewController {
                     snapshot.appendSections([.footer])
                 }
                 snapshot.appendItems([.confirmLoadMore], toSection: .footer)
-                await dataSource.apply(snapshot, animatingDifferences: false)
+                await apply(snapshot, animatingDifferences: false)
             }
             for await _ in confirmLoadMore.values {
                 return true
@@ -94,14 +94,14 @@ extension TimelineLikeCollectionViewController {
         } else {
             snapshot.appendItems([.loadingIndicator], toSection: .footer)
         }
-        await dataSource.apply(snapshot, animatingDifferences: false)
+        await apply(snapshot, animatingDifferences: false)
     }
     
     func handleRemoveLoadingIndicator() async {
         let oldContentOffset = collectionView.contentOffset
         var snapshot = dataSource.snapshot()
         snapshot.deleteSections([.footer])
-        await dataSource.apply(snapshot, animatingDifferences: false)
+        await apply(snapshot, animatingDifferences: false)
         // prevent the collection view from scrolling as we remove the loading indicator and add the timeline items
         collectionView.contentOffset = oldContentOffset
     }
@@ -123,7 +123,7 @@ extension TimelineLikeCollectionViewController {
         }
         snapshot.appendSections([.entries])
         snapshot.appendItems(timelineItems.map { .fromTimelineItem($0) }, toSection: .entries)
-        await dataSource.apply(snapshot, animatingDifferences: false)
+        await apply(snapshot, animatingDifferences: false)
     }
     
     func handleLoadNewerError(_ error: Swift.Error) async {
@@ -156,7 +156,7 @@ extension TimelineLikeCollectionViewController {
         } else {
             snapshot.appendItems(items, toSection: .entries)
         }
-        await dataSource.apply(snapshot, animatingDifferences: false)
+        await apply(snapshot, animatingDifferences: false)
         
         if let first,
            let indexPath = dataSource.indexPath(for: first) {
@@ -183,11 +183,20 @@ extension TimelineLikeCollectionViewController {
             snapshot.deleteItems([.confirmLoadMore])
         }
         snapshot.appendItems(timelineItems.map { .fromTimelineItem($0) }, toSection: .entries)
-        await dataSource.apply(snapshot, animatingDifferences: false)
+        await apply(snapshot, animatingDifferences: false)
     }
 }
 
 extension TimelineLikeCollectionViewController {
+    // apply(_:animatingDifferences:) is marked as nonisolated, so just awaiting it doesn't dispatch to the main thread, unlike other async @MainActor methods
+    // but we always want to update the data source on the main thread for consistency, so this method does that
+    func apply(_ snapshot: NSDiffableDataSourceSnapshot<Section, Item>, animatingDifferences: Bool) async {
+        let task = Task { @MainActor in
+            self.dataSource.apply(snapshot, animatingDifferences: animatingDifferences)
+        }
+        await task.value
+    }
+    
     func registerTimelineLikeCells() {
         collectionView.register(LoadingCollectionViewCell.self, forCellWithReuseIdentifier: "loadingIndicator")
         collectionView.register(ConfirmLoadMoreCollectionViewCell.self, forCellWithReuseIdentifier: "confirmLoadMore")