Set visible ranges on the home screen sliding sync view (#342)

* Set visible ranges on the home screen sliding sync view
* Prevent the visible items from being updated while in search mode
* Enable diffs on invalidations as they seem to fix duplicated events in the home screen room list
* Promoted some diffing logs to info from verbose

ElementX/Sources/Screens/HomeScreen/HomeScreenModels.swift

@@ -36,6 +36,7 @@ enum HomeScreenViewAction {
     case userMenu(action: HomeScreenViewUserMenuAction)
     case verifySession
     case skipSessionVerification
+    case updatedVisibleItemIdentifiers(Set<String>)
 }
 
 enum HomeScreenRoomListMode {

ElementX/Sources/Screens/HomeScreen/HomeScreenViewModel.swift

@@ -115,6 +115,8 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
             callback?(.verifySession)
         case .skipSessionVerification:
             state.showSessionVerificationBanner = false
+        case .updatedVisibleItemIdentifiers(let identifiers):
+            updateVisibleRange(visibleItemIdentifiers: identifiers)
         }
     }
     
@@ -189,4 +191,20 @@ class HomeScreenViewModel: HomeScreenViewModelType, HomeScreenViewModelProtocol
         state.rooms = rooms
         roomsForIdentifiers = newRoomsForIdentifiers
     }
+    
+    private func updateVisibleRange(visibleItemIdentifiers items: Set<String>) {
+        let result = items.compactMap { itemIdentifier in
+            state.rooms.firstIndex { $0.id == itemIdentifier }
+        }.sorted()
+        
+        guard !result.isEmpty else {
+            return
+        }
+        
+        guard let lowerBound = result.first, let upperBound = result.last else {
+            return
+        }
+        
+        userSession.clientProxy.roomSummaryProvider?.updateVisibleRange(lowerBound...upperBound)
+    }
 }

ElementX/Sources/Screens/HomeScreen/View/HomeScreen.swift

@@ -18,9 +18,10 @@ import SwiftUI
 
 struct HomeScreen: View {
     @State private var showingLogoutConfirmation = false
-    @ObservedObject var context: HomeScreenViewModel.Context
+    @State private var visibleItemIdentifiers = Set<String>()
+    @State private var scrollViewAdapter = ScrollViewAdapter()
     
-    // MARK: Views
+    @ObservedObject var context: HomeScreenViewModel.Context
     
     var body: some View {
         ScrollView {
@@ -40,11 +41,19 @@ struct HomeScreen: View {
             } else {
                 LazyVStack {
                     ForEach(context.viewState.visibleRooms) { room in
-                        if room.isPlaceholder {
-                            HomeScreenRoomCell(room: room, context: context)
-                                .redacted(reason: .placeholder)
-                        } else {
-                            HomeScreenRoomCell(room: room, context: context)
+                        Group {
+                            if room.isPlaceholder {
+                                HomeScreenRoomCell(room: room, context: context)
+                                    .redacted(reason: .placeholder)
+                            } else {
+                                HomeScreenRoomCell(room: room, context: context)
+                            }
+                        }
+                        .onAppear {
+                            visibleItemIdentifiers.insert(room.id)
+                        }
+                        .onDisappear {
+                            visibleItemIdentifiers.remove(room.id)
                         }
                     }
                 }
@@ -52,6 +61,10 @@ struct HomeScreen: View {
                 .searchable(text: $context.searchQuery)
             }
         }
+        .introspectScrollView { scrollView in
+            guard scrollView != scrollViewAdapter.scrollView else { return }
+            scrollViewAdapter.scrollView = scrollView
+        }
         .disabled(context.viewState.roomListMode == .skeletons)
         .animation(.elementDefault, value: context.viewState.showSessionVerificationBanner)
         .animation(.elementDefault, value: context.viewState.roomListMode)
@@ -63,6 +76,14 @@ struct HomeScreen: View {
                 userMenuButton
             }
         }
+        .onReceive(scrollViewAdapter.isScrolling) { isScrolling in
+            guard context.viewState.bindings.searchQuery.isEmpty,
+                  !isScrolling else {
+                return
+            }
+            
+            context.send(viewAction: .updatedVisibleItemIdentifiers(visibleItemIdentifiers))
+        }
     }
 
     @ViewBuilder