Fix visible room sliding sync view ranges changing while inside rooms

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

@@ -17,13 +17,21 @@
 import SwiftUI
 
 struct HomeScreen: View {
+    enum Constants {
+        static let slidingWindowBoundsPadding = 5
+    }
+    
     @ObservedObject var context: HomeScreenViewModel.Context
     
+    @State private var isViewVisible = false
+    
     @State private var scrollViewAdapter = ScrollViewAdapter()
     @State private var showingLogoutConfirmation = false
     @State private var visibleItemIdentifiers = Set<String>() {
         didSet {
-            updateVisibleRange()
+            if isViewVisible {
+                updateVisibleRange()
+            }
         }
     }
     
@@ -69,6 +77,12 @@ struct HomeScreen: View {
                 .disableAutocorrection(true)
             }
         }
+        .onAppear {
+            isViewVisible = true
+        }
+        .onDisappear {
+            isViewVisible = false
+        }
         .introspectScrollView { scrollView in
             guard scrollView != scrollViewAdapter.scrollView else { return }
             scrollViewAdapter.scrollView = scrollView
@@ -198,7 +212,10 @@ struct HomeScreen: View {
             return
         }
         
-        context.send(viewAction: .updateVisibleItemRange(range: firstIndex..<lastIndex, isScrolling: scrollViewAdapter.isScrolling.value))
+        let lowerBound = max(0, firstIndex - Constants.slidingWindowBoundsPadding)
+        let upperBound = min(Int(context.viewState.rooms.count), lastIndex + Constants.slidingWindowBoundsPadding)
+        
+        context.send(viewAction: .updateVisibleItemRange(range: lowerBound..<upperBound, isScrolling: scrollViewAdapter.isScrolling.value))
     }
 }