pr suggestions

ElementX/Sources/Services/Room/JoinedRoomProxy.swift

@@ -34,7 +34,14 @@ class JoinedRoomProxy: JoinedRoomProxyProtocol {
     
     var ownUserID: String { room.ownUserId() }
     
-    lazy var predecessorRoom: PredecessorRoom? = room.predecessorRoom()
+    // The predecessor is set on room creation and never changes, so we lazily store it.
+    lazy var predecessorRoom = room.predecessorRoom()
+    
+    // The successor may change over time, so we access it dynamically.
+    // It's suggested to observe it through the `infoPublisher`
+    var successorRoom: SuccessorRoom? {
+        room.successorRoom()
+    }
     
     let timeline: TimelineProxyProtocol
     

ElementX/Sources/Services/Room/RoomProxyProtocol.swift

@@ -78,6 +78,8 @@ protocol JoinedRoomProxyProtocol: RoomProxyProtocol {
     
     var predecessorRoom: PredecessorRoom? { get }
     
+    var successorRoom: SuccessorRoom? { get }
+    
     func subscribeForUpdates() async
     
     func subscribeToRoomInfoUpdates()

ElementX/Sources/Services/Room/RoomSummary/RoomSummary.swift

@@ -55,7 +55,6 @@ struct RoomSummary {
     
     let isMarkedUnread: Bool
     let isFavourite: Bool
-    
     let isTombstoned: Bool
     
     var hasUnreadMessages: Bool { unreadMessagesCount > 0 }

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

@@ -480,11 +480,12 @@ class TimelineController: TimelineControllerProtocol {
             case .readMarker:
                 return ReadMarkerRoomTimelineItem(id: .virtual(uniqueID: uniqueID))
             case .timelineStart:
-                if hasPredecessor {
+                // We always display the timeline start item, if there is a predecessor room.
+                guard !hasPredecessor else {
                     return TimelineStartRoomTimelineItem(name: roomDisplayName)
-                } else {
-                    return isDM ? nil : TimelineStartRoomTimelineItem(name: roomDisplayName)
                 }
+                // If not we only display the timeline start item if this is not a DM.
+                return isDM ? nil : TimelineStartRoomTimelineItem(name: roomDisplayName)
             }
         case .unknown:
             return nil

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

@@ -8,6 +8,7 @@
 import Foundation
 
 struct TimelineStartRoomTimelineItem: DecorationTimelineItemProtocol, Equatable {
+    // Using a static identifier makes the animations consistent in SwiftUI
     let id: TimelineItemIdentifier = .virtual(uniqueID: .init("TimelineStart"))
     let name: String?
 }