Improve empty state for lists (IOS-287)

Localization/app.json

@@ -491,6 +491,9 @@
                 "offline": "Offline",
                 "new_posts": "New Posts",
                 "post_sent": "Post Sent"
+            },
+            "empty_state": {
+                "list_empty_message_title": "This list is empty"
             }
         },
         "suggestion_account": {

Mastodon/Scene/HomeTimeline/HomeTimelineViewController.swift

@@ -29,6 +29,10 @@ final class HomeTimelineViewController: UIViewController, NeedsDependency, Media
 
     let mediaPreviewTransitionController = MediaPreviewTransitionController()
     
+    enum EmptyViewUseCase {
+        case timeline, list
+    }
+
     let friendsAssetImageView: UIImageView = {
         let imageView = UIImageView()
         imageView.image = Asset.Asset.friends.image
@@ -335,9 +339,12 @@ extension HomeTimelineViewController {
         
         viewModel?.timelineIsEmpty
             .receive(on: DispatchQueue.main)
-            .sink { [weak self] isEmpty in
+            .sink { [weak self] state in
-                if isEmpty {
+                guard let state else {
-                    self?.showEmptyView()
+                    self?.emptyView.removeFromSuperview()
+                    return
+                }
+                self?.showEmptyView(state)
 
                 let userDoesntFollowPeople: Bool
                 if let authContext = self?.authContext,
@@ -351,9 +358,6 @@ extension HomeTimelineViewController {
                     self?.findPeopleButtonPressed(self)
                     self?.viewModel?.presentedSuggestions = true
                 }
-                } else {
-                    self?.emptyView.removeFromSuperview()
-                }
             }
             .store(in: &disposeBag)
         
@@ -478,7 +482,7 @@ extension HomeTimelineViewController {
 }
 
 extension HomeTimelineViewController {
-    func showEmptyView() {
+    func showEmptyView(_ state: HomeTimelineViewModel.EmptyViewState) {
         if emptyView.superview != nil {
             return
         }
@@ -494,6 +498,18 @@ extension HomeTimelineViewController {
         if emptyView.arrangedSubviews.count > 0 {
             return
         }
+
+        switch state {
+        case .list:
+            let noStatusesLabel: UILabel = {
+                let label = UILabel()
+                label.text = L10n.Scene.HomeTimeline.EmptyState.listEmptyMessageTitle
+                label.textColor = Asset.Colors.Label.secondary.color
+                label.textAlignment = .center
+                return label
+            }()
+            emptyView.addArrangedSubview(noStatusesLabel)
+        case .timeline:
             let findPeopleButton: PrimaryActionButton = {
                 let button = PrimaryActionButton()
                 button.setTitle(L10n.Common.Controls.Actions.findPeople, for: .normal)
@@ -537,6 +553,7 @@ extension HomeTimelineViewController {
             buttonContainerStackView.addArrangedSubview(findPeopleButton)
             buttonContainerStackView.addArrangedSubview(manuallySearchButton)
         }
+    }
 }
 
 //MARK: - Actions

Mastodon/Scene/HomeTimeline/HomeTimelineViewModel+LoadLatestState.swift

@@ -105,6 +105,7 @@ extension HomeTimelineViewModel.LoadLatestState {
 
         guard let viewModel else { return }
 
+        viewModel.timelineIsEmpty.send(nil)
         
         Task { @MainActor in
             let latestFeedRecords = viewModel.dataController.records
@@ -170,7 +171,19 @@ extension HomeTimelineViewModel.LoadLatestState {
                     
                     viewModel.dataController.records = (toAdd + latestFeedRecords).removingDuplicates()
                 }
-                viewModel.timelineIsEmpty.value = latestStatusIDs.isEmpty && statuses.isEmpty
+
+                viewModel.timelineIsEmpty.value = (latestStatusIDs.isEmpty && statuses.isEmpty) ? {
+                    switch viewModel.timelineContext {
+                    case .home:
+                        return .timeline
+                    case .public:
+                        return .timeline
+                    case .list:
+                        return .list
+                    case .hashtag:
+                        return .list
+                    }
+                }() : nil
 
                 if !isUserInitiated {
                     FeedbackGenerator.shared.generate(.impact(.light))

Mastodon/Scene/HomeTimeline/HomeTimelineViewModel.swift

@@ -44,10 +44,14 @@ final class HomeTimelineViewModel: NSObject {
         }
     }
     
+    enum EmptyViewState {
+        case timeline, list
+    }
+
     weak var tableView: UITableView?
     weak var timelineMiddleLoaderTableViewCellDelegate: TimelineMiddleLoaderTableViewCellDelegate?
     
-    let timelineIsEmpty = CurrentValueSubject<Bool, Never>(false)
+    let timelineIsEmpty = CurrentValueSubject<EmptyViewState?, Never>(nil)
     let homeTimelineNeedRefresh = PassthroughSubject<Void, Never>()
     
     // output

MastodonSDK/Sources/MastodonLocalization/Generated/Strings.swift

@@ -857,6 +857,10 @@ public enum L10n {
     public enum HomeTimeline {
       /// Home
       public static let title = L10n.tr("Localizable", "Scene.HomeTimeline.Title", fallback: "Home")
+      public enum EmptyState {
+        /// This list is empty
+        public static let listEmptyMessageTitle = L10n.tr("Localizable", "Scene.HomeTimeline.EmptyState.ListEmptyMessageTitle", fallback: "This list is empty")
+      }
       public enum TimelineMenu {
         /// Following
         public static let following = L10n.tr("Localizable", "Scene.HomeTimeline.TimelineMenu.Following", fallback: "Following")

MastodonSDK/Sources/MastodonLocalization/Resources/Base.lproj/Localizable.strings

@@ -303,6 +303,7 @@ uploaded to Mastodon.";
 "Scene.Follower.Title" = "follower";
 "Scene.Following.Footer" = "Follows from other servers are not displayed.";
 "Scene.Following.Title" = "following";
+"Scene.HomeTimeline.EmptyState.ListEmptyMessageTitle" = "This list is empty";
 "Scene.HomeTimeline.TimelineMenu.Following" = "Following";
 "Scene.HomeTimeline.TimelineMenu.LocalCommunity" = "Local";
 "Scene.HomeTimeline.TimelineMenu.Lists.Title" = "Lists";