Add support for the new TimelineStart timeline item and new paginatio…

…n API. Remove identifiers from individual timeline items and only set them in the TimelineTableViewController

ElementX/Sources/Screens/RoomScreen/RoomScreenViewModel.swift

@@ -21,6 +21,7 @@ typealias RoomScreenViewModelType = StateStoreViewModel<RoomScreenViewState, Roo
 
 class RoomScreenViewModel: RoomScreenViewModelType, RoomScreenViewModelProtocol {
     private enum Constants {
+        static let backPaginationEventLimit: UInt = 20
         static let backPaginationPageSize: UInt = 50
     }
 
@@ -121,7 +122,7 @@ class RoomScreenViewModel: RoomScreenViewModelType, RoomScreenViewModelProtocol
     // MARK: - Private
 
     private func paginateBackwards() async {
-        switch await timelineController.paginateBackwards(Constants.backPaginationPageSize) {
+        switch await timelineController.paginateBackwards(eventLimit: Constants.backPaginationEventLimit, totalItemCount: Constants.backPaginationPageSize) {
         case .failure:
             displayError(.alert(ElementL10n.roomTimelineBackpaginationFailure))
         default:

ElementX/Sources/Screens/RoomScreen/View/Timeline/EmoteRoomTimelineView.swift

@@ -31,7 +31,6 @@ struct EmoteRoomTimelineView: View {
                 }
             }
         }
-        .id(timelineItem.id)
     }
 }
 

ElementX/Sources/Screens/RoomScreen/View/Timeline/EncryptedRoomTimelineView.swift

@@ -26,20 +26,19 @@ struct EncryptedRoomTimelineView: View {
             Button {
                 showEncryptionInfo = !showEncryptionInfo
             } label: {
-                HStack(alignment: .top) {
-                    Image(systemName: "lock.shield")
-                        .foregroundColor(.red)
-                        .padding(.top, 1.0)
+                Label {
                     if showEncryptionInfo {
                         FormattedBodyText(text: encryptionDetails)
                     } else {
                         FormattedBodyText(text: timelineItem.text)
                     }
+                } icon: {
+                    Image(systemName: "lock.shield")
+                        .foregroundColor(.red)
                 }
                 .animation(nil, value: showEncryptionInfo)
             }
         }
-        .id(timelineItem.id)
     }
 
     private var encryptionDetails: String {

ElementX/Sources/Screens/RoomScreen/View/Timeline/FileRoomTimelineView.swift

@@ -30,7 +30,6 @@ struct FileRoomTimelineView: View {
             .padding(.vertical, 12)
             .padding(.horizontal, 6)
         }
-        .id(timelineItem.id)
     }
 }
 

ElementX/Sources/Screens/RoomScreen/View/Timeline/ImageRoomTimelineView.swift

@@ -44,7 +44,6 @@ struct ImageRoomTimelineView: View {
                 .aspectRatio(timelineItem.aspectRatio, contentMode: .fit)
             }
         }
-        .id(timelineItem.id)
         .animation(.elementDefault, value: timelineItem.image)
     }
 }

ElementX/Sources/Screens/RoomScreen/View/Timeline/NoticeRoomTimelineView.swift

@@ -31,7 +31,6 @@ struct NoticeRoomTimelineView: View {
                 }
             }
         }
-        .id(timelineItem.id)
     }
 }
 

ElementX/Sources/Screens/RoomScreen/View/Timeline/ReadMarkerRoomTimelineView.swift

@@ -24,7 +24,6 @@ struct ReadMarkerRoomTimelineView: View {
         VStack {
             Spacer(minLength: 4.0)
             Divider()
-                .id(timelineItem.id)
                 .frame(maxWidth: .infinity)
                 .overlay(Color.element.accent)
         }

ElementX/Sources/Screens/RoomScreen/View/Timeline/RedactedRoomTimelineView.swift

@@ -27,7 +27,6 @@ struct RedactedRoomTimelineView: View {
                 FormattedBodyText(text: timelineItem.text)
             }
         }
-        .id(timelineItem.id)
     }
 }
 

ElementX/Sources/Screens/RoomScreen/View/Timeline/SeparatorRoomTimelineView.swift

@@ -14,7 +14,6 @@
 // limitations under the License.
 //
 
-import Foundation
 import SwiftUI
 
 struct SeparatorRoomTimelineView: View {
@@ -24,7 +23,6 @@ struct SeparatorRoomTimelineView: View {
         Text(timelineItem.text)
             .font(.element.footnote)
             .foregroundColor(.element.secondaryContent)
-            .id(timelineItem.id)
             .padding(.vertical, 24)
             .frame(maxWidth: .infinity)
     }

ElementX/Sources/Screens/RoomScreen/View/Timeline/StickerRoomTimelineView.swift

@@ -44,7 +44,6 @@ struct StickerRoomTimelineView: View {
                 .aspectRatio(timelineItem.aspectRatio, contentMode: .fit)
             }
         }
-        .id(timelineItem.id)
         .animation(.elementDefault, value: timelineItem.image)
         .accessibilityLabel(timelineItem.text)
     }

ElementX/Sources/Screens/RoomScreen/View/Timeline/TextRoomTimelineView.swift

@@ -28,7 +28,6 @@ struct TextRoomTimelineView: View {
                 FormattedBodyText(text: timelineItem.text)
             }
         }
-        .id(timelineItem.id)
     }
 }
 

ElementX/Sources/Screens/RoomScreen/View/Timeline/TimelineStartRoomTimelineView.swift

@@ -0,0 +1,44 @@
+//
+// Copyright 2023 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import SwiftUI
+
+struct TimelineStartRoomTimelineView: View {
+    let timelineItem: TimelineStartRoomTimelineItem
+
+    var body: some View {
+        Text(title)
+            .font(.element.footnote)
+            .foregroundColor(.element.secondaryContent)
+            .padding(.vertical, 24)
+            .frame(maxWidth: .infinity)
+    }
+
+    var title: String {
+        var text = ElementL10n.thisIsTheBeginningOfRoomNoName
+        if let name = timelineItem.name {
+            text = ElementL10n.thisIsTheBeginningOfRoom(name)
+        }
+        return text
+    }
+}
+
+struct TimelineStartRoomTimelineView_Previews: PreviewProvider {
+    static var previews: some View {
+        let item = TimelineStartRoomTimelineItem(name: "Alice and Bob")
+        TimelineStartRoomTimelineView(timelineItem: item)
+    }
+}

ElementX/Sources/Screens/RoomScreen/View/Timeline/UnsupportedRoomTimelineView.swift

@@ -21,18 +21,22 @@ struct UnsupportedRoomTimelineView: View {
 
     var body: some View {
         TimelineStyler(timelineItem: timelineItem) {
-            VStack(alignment: .leading) {
-                Text("\(timelineItem.text): \(timelineItem.eventType)")
-                    .fixedSize(horizontal: false, vertical: true)
-                    .foregroundColor(.element.alert)
-
-                Text(timelineItem.error)
-                    .fixedSize(horizontal: false, vertical: true)
-                    .foregroundColor(.element.alert)
-                    .font(.element.callout)
+            Label {
+                VStack(alignment: .leading) {
+                    Text("\(timelineItem.text): \(timelineItem.eventType)")
+                        .fixedSize(horizontal: false, vertical: true)
+                        .foregroundColor(.element.primaryContent)
+
+                    Text(timelineItem.error)
+                        .fixedSize(horizontal: false, vertical: true)
+                        .font(.element.footnote)
+                        .foregroundColor(.element.primaryContent)
+                }
+            } icon: {
+                Image(systemName: "exclamationmark.bubble")
+                    .foregroundColor(.red)
             }
         }
-        .id(timelineItem.id)
     }
 }
 

ElementX/Sources/Screens/RoomScreen/View/Timeline/VideoRoomTimelineView.swift

@@ -40,7 +40,6 @@ struct VideoRoomTimelineView: View {
                 .aspectRatio(timelineItem.aspectRatio, contentMode: .fit)
             }
         }
-        .id(timelineItem.id)
         .animation(.elementDefault, value: timelineItem.image)
     }
 

ElementX/Sources/Screens/RoomScreen/View/TimelineTableViewController.swift

@@ -192,6 +192,7 @@ class TimelineTableViewController: UIViewController {
             cell.item = timelineItem
             cell.contentConfiguration = UIHostingConfiguration {
                 timelineItem
+                    .id(timelineItem.id)
                     .frame(maxWidth: .infinity, alignment: .leading)
                     .opacity(opacity)
                     .contextMenu {

ElementX/Sources/Services/Room/MockRoomProxy.swift

@@ -55,7 +55,7 @@ struct MockRoomProxy: RoomProxyProtocol {
         .failure(.failedAddingTimelineListener)
     }
 
-    func paginateBackwards(count: UInt) async -> Result<UInt, RoomProxyError> {
+    func paginateBackwards(eventLimit: UInt, totalItemCount: UInt) async -> Result<Void, RoomProxyError> {
         .failure(.failedPaginatingBackwards)
     }
 

ElementX/Sources/Services/Room/RoomProxy.swift

@@ -34,8 +34,6 @@ class RoomProxy: RoomProxyProtocol {
 
     private(set) var displayName: String?
 
-    private var backPaginationOutcome: PaginationOutcome?
-
     private var timelineObservationToken: StoppableSpawn?
 
     deinit {
@@ -138,17 +136,13 @@ class RoomProxy: RoomProxyProtocol {
         }
     }
 
-    func paginateBackwards(count: UInt) async -> Result<UInt, RoomProxyError> {
-        guard backPaginationOutcome?.moreMessages != false else {
-            return .failure(.noMoreMessagesToBackPaginate)
-        }
-
+    func paginateBackwards(eventLimit: UInt, totalItemCount: UInt) async -> Result<Void, RoomProxyError> {
         do {
-            let outcome: PaginationOutcome = try await Task.dispatch(on: .global()) {
-                try self.room.paginateBackwards(limit: UInt16(count))
+            try await Task.dispatch(on: .global()) {
+                try self.room.paginateBackwards(opts: .untilNumItems(eventLimit: UInt16(eventLimit), items: UInt16(totalItemCount)))
             }
-            update(backPaginationOutcome: outcome)
-            return .success(UInt(outcome.numUpdates))
+
+            return .success(())
         } catch {
             return .failure(.failedPaginatingBackwards)
         }
@@ -255,8 +249,4 @@ class RoomProxy: RoomProxyProtocol {
     private func update(displayName: String) {
         self.displayName = displayName
     }
-
-    private func update(backPaginationOutcome: PaginationOutcome) {
-        self.backPaginationOutcome = backPaginationOutcome
-    }
 }

ElementX/Sources/Services/Room/RoomProxyProtocol.swift

@@ -56,7 +56,7 @@ protocol RoomProxyProtocol {
 
     func addTimelineListener(listener: TimelineListener) -> Result<Void, RoomProxyError>
 
-    func paginateBackwards(count: UInt) async -> Result<UInt, RoomProxyError>
+    func paginateBackwards(eventLimit: UInt, totalItemCount: UInt) async -> Result<Void, RoomProxyError>
 
     func sendMessage(_ message: String, inReplyToEventId: String?) async -> Result<Void, RoomProxyError>
 

ElementX/Sources/Services/Timeline/MockRoomTimelineProvider.swift

@@ -23,7 +23,7 @@ struct MockRoomTimelineProvider: RoomTimelineProviderProtocol {
 
     private var itemProxies = [TimelineItemProxy]()
 
-    func paginateBackwards(_ count: UInt) async -> Result<Void, RoomTimelineProviderError> {
+    func paginateBackwards(eventLimit: UInt, totalItemCount: UInt) async -> Result<Void, RoomTimelineProviderError> {
         .failure(.failedPaginatingBackwards)
     }
 

ElementX/Sources/Services/Timeline/RoomTimelineProvider.swift

@@ -68,18 +68,14 @@ class RoomTimelineProvider: RoomTimelineProviderProtocol {
         }
     }
 
-    func paginateBackwards(_ count: UInt) async -> Result<Void, RoomTimelineProviderError> {
+    func paginateBackwards(eventLimit: UInt, totalItemCount: UInt) async -> Result<Void, RoomTimelineProviderError> {
         // Set this back to false after actually updating the items or if failed
         backPaginationPublisher.send(true)
 
         MXLog.info("Started back pagination request")
-        switch await roomProxy.paginateBackwards(count: count) {
-        case .success(let numberOfUpdates):
-            MXLog.info("Finished back pagination request. Got \(numberOfUpdates) updates")
-
-            if numberOfUpdates == 0 {
-                backPaginationPublisher.send(false)
-            }
+        switch await roomProxy.paginateBackwards(eventLimit: eventLimit, totalItemCount: totalItemCount) {
+        case .success:
+            MXLog.info("Finished back pagination request")
             return .success(())
         case .failure(let error):
             MXLog.error("Failed back pagination request with error: \(error)")

ElementX/Sources/Services/Timeline/RoomTimelineProviderProtocol.swift

@@ -31,7 +31,7 @@ protocol RoomTimelineProviderProtocol {
 
     var backPaginationPublisher: CurrentValueSubject<Bool, Never> { get }
 
-    func paginateBackwards(_ count: UInt) async -> Result<Void, RoomTimelineProviderError>
+    func paginateBackwards(eventLimit: UInt, totalItemCount: UInt) async -> Result<Void, RoomTimelineProviderError>
 
     func sendMessage(_ message: String, inReplyToItemId: String?) async -> Result<Void, RoomTimelineProviderError>
 

ElementX/Sources/Services/Timeline/TimelineController/MockRoomTimelineController.swift

@@ -50,7 +50,7 @@ class MockRoomTimelineController: RoomTimelineControllerProtocol {
         }
     }
 
-    func paginateBackwards(_ count: UInt) async -> Result<Void, RoomTimelineControllerError> {
+    func paginateBackwards(eventLimit: UInt, totalItemCount: UInt) async -> Result<Void, RoomTimelineControllerError> {
         callbacks.send(.startedBackPaginating)
 
         guard !backPaginationResponses.isEmpty else {

ElementX/Sources/Services/Timeline/TimelineController/RoomTimelineController.swift

@@ -78,8 +78,8 @@ class RoomTimelineController: RoomTimelineControllerProtocol {
         NotificationCenter.default.addObserver(self, selector: #selector(contentSizeCategoryDidChange), name: UIContentSizeCategory.didChangeNotification, object: nil)
     }
 
-    func paginateBackwards(_ count: UInt) async -> Result<Void, RoomTimelineControllerError> {
-        switch await timelineProvider.paginateBackwards(count) {
+    func paginateBackwards(eventLimit: UInt, totalItemCount: UInt) async -> Result<Void, RoomTimelineControllerError> {
+        switch await timelineProvider.paginateBackwards(eventLimit: eventLimit, totalItemCount: totalItemCount) {
         case .success:
             return .success(())
         case .failure(let error):
@@ -262,6 +262,8 @@ class RoomTimelineController: RoomTimelineControllerProtocol {
                     }
                 case .loadingIndicator:
                     newTimelineItems.append(PaginationIndicatorRoomTimelineItem())
+                case .timelineStart:
+                    newTimelineItems.append(TimelineStartRoomTimelineItem(name: roomProxy.displayName ?? roomProxy.name))
                 }
             default:
                 break

ElementX/Sources/Services/Timeline/TimelineController/RoomTimelineControllerProtocol.swift

@@ -48,7 +48,7 @@ protocol RoomTimelineControllerProtocol {
 
     func processItemTap(_ itemId: String) async -> RoomTimelineControllerAction
 
-    func paginateBackwards(_ count: UInt) async -> Result<Void, RoomTimelineControllerError>
+    func paginateBackwards(eventLimit: UInt, totalItemCount: UInt) async -> Result<Void, RoomTimelineControllerError>
 
     func sendMessage(_ message: String) async
 

ElementX/Sources/Services/Timeline/TimelineItems/Items/TimelineStartRoomTimelineItem.swift

@@ -0,0 +1,22 @@
+//
+// Copyright 2023 New Vector Ltd
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+//
+
+import Foundation
+
+struct TimelineStartRoomTimelineItem: DecorationTimelineItemProtocol, Identifiable, Hashable {
+    let id: String = UUID().uuidString
+    let name: String?
+}

ElementX/Sources/Services/Timeline/TimelineItems/RoomTimelineViewFactory.swift

@@ -46,6 +46,8 @@ struct RoomTimelineViewFactory: RoomTimelineViewFactoryProtocol {
             return .sticker(item)
         case let item as UnsupportedRoomTimelineItem:
             return .unsupported(item)
+        case let item as TimelineStartRoomTimelineItem:
+            return .timelineStart(item)
         default:
             fatalError("Unknown timeline item")
         }