Actually connect User::nameChanged to Room; make a new Room::memberRenamed signal, which clients should use in the room context.

Processing changes of user displaynames is tricky: we have to not only deal with the currently renamed user but also with its past and new namesakes which might change representation due to that renaming. So in the worst case a single User::nameChanged signal may lead to three Room::memberRenamed references (and 3 user displaynames updated in the UI, respectively). And the newly added users should be taken care of in a similar manner, of course.

2 files changed, 47 insertions, 10 deletions

diff --git a/room.cpp b/room.cpp
index 5b6a3a30..ac4275af 100644
--- a/room.cpp
+++ b/room.cpp
@@ -89,6 +89,9 @@ class Room::Private: public QObject
     private:
         QString calculateDisplayname() const;
         QString roomNameFromMemberNames(const QList<User*>& userlist) const;
+
+        void insertMemberIntoMap(User* u);
+        void removeMemberFromMap(QString username, User* u);
 };
 
 Room::Room(Connection* connection, QString id)
@@ -209,12 +212,37 @@ QList< User* > Room::users() const
     return d->membersMap.values();
 }
 
+void Room::Private::insertMemberIntoMap(User *u)
+{
+    QList<User*> namesakes = membersMap.values(u->name());
+    membersMap.insert(u->name(), u);
+    // If there is exactly one namesake of the added user, signal member renaming
+    // for that other one because the two should be disambiguated now.
+    if (namesakes.size() == 1)
+        emit q->memberRenamed(namesakes[0]);
+
+    updateDisplayname();
+}
+
+void Room::Private::removeMemberFromMap(QString username, User* u)
+{
+    membersMap.remove(username, u);
+    // If there was one namesake besides the removed user, signal member renaming
+    // for it because it doesn't need to be disambiguated anymore.
+    // TODO: Think about left users.
+    QList<User*> formerNamesakes = membersMap.values(username);
+    if (formerNamesakes.size() == 1)
+        emit q->memberRenamed(formerNamesakes[0]);
+
+    updateDisplayname();
+}
+
 void Room::Private::addMember(User *u)
 {
-    if (!membersMap.values(u->name()).contains(u))
+    if (!hasMember(u))
     {
-        membersMap.insert(u->name(), u);
-        updateDisplayname();
+        insertMemberIntoMap(u);
+        connect(u, &User::nameChanged, q, &Room::userRenamed);
         emit q->userAdded(u);
     }
 }
@@ -232,11 +260,20 @@ User* Room::Private::member(QString id) const
 
 void Room::Private::renameMember(User* u, QString oldName)
 {
-    // We can't use hasUser because we need to search by oldName
+    if (hasMember(u))
+    {
+        qWarning() << "Room::Private::renameMember(): the user "
+                   << u->name()
+                   << "is already known in the room under a new name.";
+        return;
+    }
+
     if (membersMap.values(oldName).contains(u))
     {
-        membersMap.remove(oldName, u);
-        membersMap.insert(u->name(), u);
+        removeMemberFromMap(oldName, u);
+        insertMemberIntoMap(u);
+        emit q->memberRenamed(u);
+
         updateDisplayname();
     }
 }
@@ -247,13 +284,12 @@ void Room::Private::removeMember(User* u)
     {
         if ( !membersLeft.contains(u) )
             membersLeft.append(u);
-        membersMap.remove(u->name(), u);
-        updateDisplayname();
+        removeMemberFromMap(u->name(), u);
         emit q->userRemoved(u);
     }
 }
 
-void Room::memberRenamed(User* user, QString oldName)
+void Room::userRenamed(User* user, QString oldName)
 {
     d->renameMember(user, oldName);
 }
diff --git a/room.h b/room.h
index 31cf17a5..831b5382 100644
--- a/room.h
+++ b/room.h
@@ -74,7 +74,7 @@ namespace QMatrixClient
 
         public slots:
             void getPreviousContent();
-            void memberRenamed(User* user, QString oldName);
+            void userRenamed(User* user, QString oldName);
 
         signals:
             void newMessage(Event* event);
@@ -88,6 +88,7 @@ namespace QMatrixClient
             void topicChanged();
             void userAdded(User* user);
             void userRemoved(User* user);
+            void memberRenamed(User* user);
             void joinStateChanged(JoinState oldState, JoinState newState);
             void typingChanged();
             void highlightCountChanged(Room* room);