feat: per-message read receipt avatars showing each user s last-read position

src/app/features/room/ReadPositionsContext.ts

@@ -0,0 +1,4 @@
+import { createContext, useContext } from 'react';
+
+export const ReadPositionsContext = createContext<Map<string, string[]>>(new Map());
+export const useReadPositions = () => useContext(ReadPositionsContext);

src/app/features/room/RoomTimeline.tsx

@@ -89,6 +89,8 @@ import { useSetting } from '../../state/hooks/settings';
 import { MessageLayout, settingsAtom } from '../../state/settings';
 import { useMatrixEventRenderer } from '../../hooks/useMatrixEventRenderer';
 import { Reactions, Message, Event, EncryptedContent } from './message';
+import { ReadPositionsContext } from './ReadPositionsContext';
+import { useRoomReadPositions } from '../../hooks/useRoomReadPositions';
 import { useMemberEventParser } from '../../hooks/useMemberEventParser';
 import * as customHtmlCss from '../../styles/CustomHtml.css';
 import { RoomIntro } from '../../components/room-intro';
@@ -441,6 +443,7 @@ export function RoomTimeline({ room, eventId, roomInputRef, editor }: RoomTimeli
   const [messageSpacing] = useSetting(settingsAtom, 'messageSpacing');
   const [legacyUsernameColor] = useSetting(settingsAtom, 'legacyUsernameColor');
   const direct = useIsDirectRoom();
+  const readPositions = useRoomReadPositions(room);
   const [hideMembershipEvents] = useSetting(settingsAtom, 'hideMembershipEvents');
   const [hideNickAvatarEvents] = useSetting(settingsAtom, 'hideNickAvatarEvents');
   const [mediaAutoLoad] = useSetting(settingsAtom, 'mediaAutoLoad');
@@ -1837,6 +1840,7 @@ export function RoomTimeline({ room, eventId, roomInputRef, editor }: RoomTimeli
   };
 
   return (
+    <ReadPositionsContext.Provider value={readPositions}>
     <Box grow="Yes" style={{ position: 'relative' }}>
       {unreadInfo?.readUptoEventId && !unreadInfo?.inLiveTimeline && (
         <TimelineFloat position="Top">
@@ -1962,5 +1966,6 @@ export function RoomTimeline({ room, eventId, roomInputRef, editor }: RoomTimeli
         </TimelineFloat>
       )}
     </Box>
+    </ReadPositionsContext.Provider>
   );
 }

src/app/features/room/message/Message.tsx

@@ -63,6 +63,8 @@ import { useMatrixClient } from '../../../hooks/useMatrixClient';
 import { useRecentEmoji } from '../../../hooks/useRecentEmoji';
 import * as css from './styles.css';
 import { EventReaders } from '../../../components/event-readers';
+import { ReadReceiptAvatars } from '../../../components/read-receipt-avatars';
+import { useReadPositions } from '../ReadPositionsContext';
 import { TextViewer } from '../../../components/text-viewer';
 import { AsyncStatus, useAsyncCallback } from '../../../hooks/useAsyncCallback';
 import { EmojiBoard } from '../../../components/emoji-board';
@@ -721,6 +723,10 @@ export const Message = as<'div', MessageProps>(
     const mx = useMatrixClient();
     const useAuthentication = useMediaAuthentication();
     const senderId = mEvent.getSender() ?? '';
+    const readPositions = useReadPositions();
+    const readReceiptUsers = hideReadReceipts
+      ? []
+      : (readPositions.get(mEvent.getId() ?? '') ?? []);
 
     const [hover, setHover] = useState(false);
     const { hoverProps } = useHover({ onHoverChange: setHover });
@@ -833,6 +839,13 @@ export const Message = as<'div', MessageProps>(
           children
         )}
         {reactions}
+        {readReceiptUsers.length > 0 && (
+          <ReadReceiptAvatars
+            room={room}
+            eventId={mEvent.getId() ?? ''}
+            userIds={readReceiptUsers}
+          />
+        )}
       </Box>
     );