fix: Room history scroll position (#29335)

Co-authored-by: gabriellsh <[email protected]>

.changeset/pretty-dots-leave.md

@@ -0,0 +1,5 @@
+---
+'@rocket.chat/meteor': minor
+---
+
+fix: Room history scrollbar position

apps/meteor/client/views/room/components/body/RoomBody.tsx

@@ -45,6 +45,7 @@ import UploadProgressIndicator from './UploadProgressIndicator';
 import ComposerContainer from './composer/ComposerContainer';
 import { useFileUploadDropTarget } from './hooks/useFileUploadDropTarget';
 import { useReadMessageWindowEvents } from './hooks/useReadMessageWindowEvents';
+import { useRestoreScrollPosition } from './hooks/useRestoreScrollPosition';
 import { useRetentionPolicy } from './hooks/useRetentionPolicy';
 import { useUnreadMessages } from './hooks/useUnreadMessages';
 
@@ -403,10 +404,10 @@ const RoomBody = (): ReactElement => {
 				sendToBottom();
 			}
 			wrapper.removeEventListener('MessageGroup', afterMessageGroup);
-
-			wrapper.addEventListener('scroll', handleWrapperScroll);
 		};
 
+		wrapper.addEventListener('scroll', handleWrapperScroll);
+
 		wrapper.addEventListener('MessageGroup', afterMessageGroup);
 
 		return () => {
@@ -415,6 +416,8 @@ const RoomBody = (): ReactElement => {
 		};
 	}, [room._id, sendToBottom]);
 
+	useRestoreScrollPosition(room._id, scrollMessageList, sendToBottom);
+
 	useEffect(() => {
 		const wrapper = wrapperRef.current;
 

apps/meteor/client/views/room/components/body/hooks/useRestoreScrollPosition.ts

@@ -0,0 +1,23 @@
+import type { IRoom } from '@rocket.chat/core-typings';
+import { useEffect } from 'react';
+
+import type { MessageListContextValue } from '../../../../../components/message/list/MessageListContext';
+import { RoomManager } from '../../../../../lib/RoomManager';
+
+export function useRestoreScrollPosition(
+	roomId: IRoom['_id'],
+	scrollMessageList: Exclude<MessageListContextValue['scrollMessageList'], undefined>,
+	sendToBottom: () => void,
+) {
+	useEffect(() => {
+		const store = RoomManager.getStore(roomId);
+
+		if (store?.scroll && !store.atBottom) {
+			scrollMessageList(() => {
+				return { left: 30, top: store.scroll };
+			});
+		} else {
+			sendToBottom();
+		}
+	}, [roomId, scrollMessageList, sendToBottom]);
+}