[Room] Add a onUpdate callback

lib/src/Room.dart

@@ -34,6 +34,8 @@ import './User.dart';
 import 'Connection.dart';
 import 'Timeline.dart';
 
+typedef onRoomUpdate = void Function();
+
 /// Represents a Matrix room.
 class Room {
   /// The full qualified Matrix ID for the room in the format '!localid:server.abc'.
@@ -64,6 +66,9 @@ class Room {
   /// ID of the fully read marker event.
   String fullyRead;
 
+  /// If something changes, this callback will be triggered.
+  onRoomUpdate onUpdate;
+
   /// The name of the room if set by a participant.
   String get name {
     if (states["m.room.name"] != null &&

lib/src/RoomList.dart

@@ -140,6 +140,7 @@ class RoomList {
         if (chatUpdate.summary.mInvitedMemberCount != null)
           rooms[j].mInvitedMemberCount = chatUpdate.summary.mInvitedMemberCount;
       }
+      if (rooms[j].onUpdate != null) rooms[j].onUpdate();
     }
     sortAndUpdate();
   }
@@ -158,6 +159,7 @@ class RoomList {
     if (rooms[j].states[stateEvent.key] != null &&
         rooms[j].states[stateEvent.key].time > stateEvent.time) return;
     rooms[j].states[stateEvent.key] = stateEvent;
+    if (rooms[j].onUpdate != null) rooms[j].onUpdate();
     sortAndUpdate();
   }
 

test/RoomList_test.dart

@@ -129,6 +129,15 @@ void main() {
 
       ChatTime now = ChatTime.now();
 
+      int roomUpdates = 0;
+
+      roomList.rooms[0].onUpdate = () {
+        roomUpdates++;
+      };
+      roomList.rooms[1].onUpdate = () {
+        roomUpdates++;
+      };
+
       client.connection.onEvent.add(EventUpdate(
           type: "timeline",
           roomID: "1",
@@ -158,6 +167,7 @@ void main() {
       await new Future.delayed(new Duration(milliseconds: 50));
 
       expect(updateCount, 4);
+      expect(roomUpdates, 2);
       expect(insertList, [0, 1]);
       expect(removeList, []);