From cdcc34acaac4150662d34f3577ccbaf39119cd09 Mon Sep 17 00:00:00 2001
From: Henry-Hiles <henry@henryhiles.com>
Date: Tue, 2 Jun 2026 21:04:23 -0400
Subject: [PATCH] remember position on load older based on event id instead of
 scroll progress

---
 lib/widgets/room_chat.dart | 60 +++++++++++++++++++++++---------------
 1 file changed, 37 insertions(+), 23 deletions(-)

diff --git a/lib/widgets/room_chat.dart b/lib/widgets/room_chat.dart
index 61fd3f8..2d98ced 100644
--- a/lib/widgets/room_chat.dart
+++ b/lib/widgets/room_chat.dart
@@ -79,11 +79,14 @@ 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;
-      await notifier.loadOlder();
+      if (controllerData
+          case AsyncData(:final value) || AsyncLoading(:final value?)) {
+        topEventBeforeLoad.value = value.firstOrNull?.eventId;
+        await notifier.loadOlder();
+      }
     }
 
     useEffect(() {
@@ -97,26 +100,37 @@ class RoomChat extends HookConsumerWidget {
     }, [scrollController.hasClients]);
 
     useEffect(() {
-      if (!scrollController.hasClients || controllerData is! AsyncData) return;
-
-      if (heightBeforeLoad.value != null) {
-        WidgetsBinding.instance.addPostFrameCallback((_) {
-          if (scrollController.hasClients) {
-            scrollController.jumpTo(
-              scrollController.position.maxScrollExtent -
-                  heightBeforeLoad.value!,
-            );
-          }
-          heightBeforeLoad.value = null;
-        });
-      } else if (scrollController.position.atEdge &&
-          scrollController.position.pixels != 0) {
-        WidgetsBinding.instance.addPostFrameCallback((_) {
-          if (scrollController.hasClients) {
-            scrollController.jumpTo(scrollController.position.maxScrollExtent);
-          }
-        });
+      if (controllerData case AsyncData(
+        :final value,
+      ) when scrollController.hasClients) {
+        if (topEventBeforeLoad.value != null) {
+          WidgetsBinding.instance.addPostFrameCallback((_) {
+            if (scrollController.hasClients) {
+              final index = value.indexWhere(
+                (event) => event.eventId == topEventBeforeLoad.value,
+              );
+              if (index != -1) {
+                listController.value.jumpToItem(
+                  index: index,
+                  scrollController: scrollController,
+                  alignment: 0,
+                );
+              }
+            }
+            topEventBeforeLoad.value = null;
+          });
+        } else if (scrollController.position.atEdge &&
+            scrollController.position.pixels != 0) {
+          WidgetsBinding.instance.addPostFrameCallback((_) {
+            if (scrollController.hasClients) {
+              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) {