Don't reverse the CustomScrollView

Helps with scrolling jank, fixes #29

lib/controllers/room_chat_controller.dart

@@ -44,16 +44,11 @@ class RoomChatController extends AsyncNotifier<IList<Event>> {
       loadOlder();
     }
 
-    return IMap<int, int?>.fromValues(
+    return room.timeline
-          keyMapper: (id) => 9999999 + (id ?? 0),
+        .toValueIList(sort: true, compare: (a, b) => (a ?? 0).compareTo(b ?? 0))
-          values: room.sticky,
+        .addAll(room.sticky)
-        )
-        .addAll(room.timeline)
-        .toEntryIList(compare: (a, b) => (b?.key ?? 0).compareTo(a?.key ?? 0))
         .map((entry) {
-          final foundEvent = entry.value == null
+          final foundEvent = entry == null ? null : room.events[entry];
-              ? null
-              : room.events[entry.value!];
 
           final editedEvent =
               foundEvent == null || foundEvent.lastEditRowId == 0

lib/widgets/room_chat.dart

@@ -78,7 +78,10 @@ class RoomChat extends HookConsumerWidget {
     final client = ref.watch(ClientController.provider.notifier);
 
     final listController = useRef(ListController());
-    final scrollController = useScrollController();
+    final scrollController = useScrollController(
+      initialScrollOffset: 99999,
+      keys: [roomId],
+    );
 
     useEffect(() {
       Future<void> listener() async {
@@ -90,9 +93,9 @@ class RoomChat extends HookConsumerWidget {
         if (room == null) return;
 
         if (scrollController.position.pixels == 0) {
-          await client.markRead(room);
-        } else {
           if (room.hasMore) await notifier.loadOlder();
+        } else {
+          await client.markRead(room);
         }
       }
 
@@ -323,7 +326,6 @@ class RoomChat extends HookConsumerWidget {
     }
 
     final controllerData = ref.watch(controllerProvider);
-
     return Scaffold(
       appBar: RoomAppbar(
         roomId: roomId,
@@ -345,12 +347,19 @@ class RoomChat extends HookConsumerWidget {
                     child: switch (controllerData) {
                       AsyncData(:final value) ||
                       AsyncLoading(:final value?) => CustomScrollView(
-                        reverse: true,
                         controller: scrollController,
                         slivers: [
-                          SliverPadding(
+                          SliverToBoxAdapter(
-                            padding: EdgeInsetsGeometry.only(
+                            child: Padding(
-                              bottom: composerSize.value,
+                              padding: EdgeInsets.symmetric(vertical: 36),
+                              child: Center(
+                                child: ElevatedButton(
+                                  onPressed: controllerData is AsyncLoading
+                                      ? null
+                                      : notifier.loadOlder,
+                                  child: Text("Load More"),
+                                ),
+                              ),
                             ),
                           ),
 
@@ -359,7 +368,7 @@ class RoomChat extends HookConsumerWidget {
                             itemCount: value.length,
                             itemBuilder: (_, index) {
                               final event = value[index];
-                              final previousEvent = value.getOrNull(index + 1);
+                              final previousEvent = value.getOrNull(index - 1);
                               return FlashWrapper(
                                 EventRenderer(
                                   event,
@@ -401,17 +410,9 @@ class RoomChat extends HookConsumerWidget {
                             },
                           ),
 
-                          SliverToBoxAdapter(
+                          SliverPadding(
-                            child: Padding(
+                            padding: EdgeInsetsGeometry.only(
-                              padding: EdgeInsets.symmetric(vertical: 36),
+                              bottom: composerSize.value,
-                              child: Center(
-                                child: controllerData is AsyncLoading
-                                    ? Loading()
-                                    : ElevatedButton(
-                                        onPressed: notifier.loadOlder,
-                                        child: Text("Load More"),
-                                      ),
-                              ),
                             ),
                           ),
                         ],