make room summary available to Room

from either the sync accumulator or the /sync endpoint

src/models/room-state.js

@@ -102,6 +102,10 @@ RoomState.prototype.getJoinedMemberCount = function() {
     return this._joinedMemberCount;
 };
 
+RoomState.prototype.setJoinedMemberCount = function(count) {
+    this._joinedMemberCount = count;
+}
+
 /**
  * Get all RoomMembers in this room.
  * @return {Array<RoomMember>} A list of RoomMembers.

src/models/room.js

@@ -172,6 +172,7 @@ function Room(roomId, opts) {
     // read by megolm; boolean value - null indicates "use global value"
     this._blacklistUnverifiedDevices = null;
     this._syncedMembership = null;
+    this._summaryHeroes = null;
 }
 
 utils.inherits(Room, EventEmitter);
@@ -377,6 +378,22 @@ Room.prototype.setUnreadNotificationCount = function(type, count) {
     this._notificationCounts[type] = count;
 };
 
+Room.prototype.setSummary = function(summary) {
+    const heros = summary["m.heros"];
+    const count = summary["m.joined_member_count"];
+    if (Number.isInteger(count)) {
+        this.currentState.setJoinedMemberCount(count);
+    }
+    this._summaryHeroes = heros;
+
+    const oldName = this.name;
+    this.name = calculateRoomName(this, userId);
+    
+    if (oldName !== this.name) {
+        this.emit("Room.name", this);
+    }
+}
+
 /**
  * Whether to send encrypted messages to devices within this room.
  * @param {Boolean} value true to blacklist unverified devices, null

src/sync-accumulator.js

@@ -63,6 +63,7 @@ class SyncAccumulator {
             //       { event: $event, token: null|token },
             //       ...
             //    ],
+            //    _summary: { m.heros: [ $user_id ], m.joined_member_count: $count }
             //    _accountData: { $event_type: json },
             //    _unreadNotifications: { ... unread_notifications JSON ... },
             //    _readReceipts: { $user_id: { data: $json, eventId: $event_id }}
@@ -242,6 +243,7 @@ class SyncAccumulator {
                 _timeline: [],
                 _accountData: Object.create(null),
                 _unreadNotifications: {},
+                _summary: {},
                 _readReceipts: {},
             };
         }
@@ -258,6 +260,9 @@ class SyncAccumulator {
         if (data.unread_notifications) {
             currentData._unreadNotifications = data.unread_notifications;
         }
+        if (data.summary) {
+            currentData._summary = data.summary;
+        }
 
         if (data.ephemeral && data.ephemeral.events) {
             data.ephemeral.events.forEach((e) => {
@@ -428,6 +433,7 @@ class SyncAccumulator {
                     prev_batch: null,
                 },
                 unread_notifications: roomData._unreadNotifications,
+                summary: roomData._summary,
             };
             // Add account data
             Object.keys(roomData._accountData).forEach((evType) => {

src/sync.js

@@ -823,6 +823,7 @@ SyncApi.prototype._processSyncResponse = async function(
     //          state: { events: [] },
     //          timeline: { events: [], prev_batch: $token, limited: true },
     //          ephemeral: { events: [] },
+    //          summary: { m.heros: [ $userId ], m.joined_member_count: $count }
     //          account_data: { events: [] },
     //          unread_notifications: {
     //              highlight_count: 0,
@@ -1056,6 +1057,13 @@ SyncApi.prototype._processSyncResponse = async function(
 
         self._processRoomEvents(room, stateEvents, timelineEvents);
 
+        // set summary after processing events,
+        // because it will trigger a name calculation
+        // which needs the room state to be up to date
+        if (joinObj.summary) {
+            room.setSummary(joinObj.summary);
+        }
+        
         // XXX: should we be adding ephemeralEvents to the timeline?
         // It feels like that for symmetry with room.addAccountData()
         // there should be a room.addEphemeralEvents() or similar.