remember position on load older based on event id instead of scroll progress

lib/widgets/room_chat.dart

@@ -79,12 +79,15 @@ class RoomChat extends HookConsumerWidget {
     final scrollController = useScrollController();
     final controllerData = ref.watch(controllerProvider);
 
-    final heightBeforeLoad = useState<double?>(null);
+    final topEventBeforeLoad = useState<String?>(null);
 
     Future<void> loadOlder() async {
-      heightBeforeLoad.value = scrollController.position.maxScrollExtent;
+      if (controllerData
+          case AsyncData(:final value) || AsyncLoading(:final value?)) {
+        topEventBeforeLoad.value = value.firstOrNull?.eventId;
         await notifier.loadOlder();
       }
+    }
 
     useEffect(() {
       WidgetsBinding.instance.addPostFrameCallback((_) {
@@ -97,26 +100,37 @@ class RoomChat extends HookConsumerWidget {
     }, [scrollController.hasClients]);
 
     useEffect(() {
-      if (!scrollController.hasClients || controllerData is! AsyncData) return;
+      if (controllerData case AsyncData(
-
+        :final value,
-      if (heightBeforeLoad.value != null) {
+      ) when scrollController.hasClients) {
+        if (topEventBeforeLoad.value != null) {
           WidgetsBinding.instance.addPostFrameCallback((_) {
             if (scrollController.hasClients) {
-            scrollController.jumpTo(
+              final index = value.indexWhere(
-              scrollController.position.maxScrollExtent -
+                (event) => event.eventId == topEventBeforeLoad.value,
-                  heightBeforeLoad.value!,
+              );
+              if (index != -1) {
+                listController.value.jumpToItem(
+                  index: index,
+                  scrollController: scrollController,
+                  alignment: 0,
                 );
               }
-          heightBeforeLoad.value = null;
+            }
+            topEventBeforeLoad.value = null;
           });
         } else if (scrollController.position.atEdge &&
             scrollController.position.pixels != 0) {
           WidgetsBinding.instance.addPostFrameCallback((_) {
             if (scrollController.hasClients) {
-            scrollController.jumpTo(scrollController.position.maxScrollExtent);
+              scrollController.jumpTo(
+                scrollController.position.maxScrollExtent,
+              );
             }
           });
         }
+      }
+
       return null;
     }, [controllerData]);
 
@@ -142,7 +156,7 @@ class RoomChat extends HookConsumerWidget {
 
       scrollController.addListener(listener);
       return () => scrollController.removeListener(listener);
-    }, [roomId]);
+    }, [roomId, controllerData]);
 
     final composerNode = useFocusNode(
       onKeyEvent: (_, event) {