Connection::provideRoom: allow omitting join state

2 files changed, 38 insertions, 14 deletions

diff --git a/lib/connection.cpp b/lib/connection.cpp
index c17cbffc..18fa91e7 100644
--- a/lib/connection.cpp
+++ b/lib/connection.cpp
@@ -981,11 +981,12 @@ const ConnectionData* Connection::connectionData() const
     return d->data.get();
 }
 
-Room* Connection::provideRoom(const QString& id, JoinState joinState)
+Room* Connection::provideRoom(const QString& id, Omittable<JoinState> joinState)
 {
     // TODO: This whole function is a strong case for a RoomManager class.
     Q_ASSERT_X(!id.isEmpty(), __FUNCTION__, "Empty room id");
 
+    // If joinState.omitted(), all joinState == comparisons below are false.
     const auto roomKey = qMakePair(id, joinState == JoinState::Invite);
     auto* room = d->roomMap.value(roomKey, nullptr);
     if (room)
@@ -995,10 +996,19 @@ Room* Connection::provideRoom(const QString& id, JoinState joinState)
         // and emit a signal. For Invite and Join, there's no such problem.
         if (room->joinState() == joinState && joinState != JoinState::Leave)
             return room;
+    } else if (joinState.omitted())
+    {
+        // No Join and Leave, maybe Invite?
+        room = d->roomMap.value({id, true}, nullptr);
+        if (room)
+            return room;
+        // No Invite either, setup a new room object below
     }
-    else
+
+    if (!room)
     {
-        room = roomFactory()(this, id, joinState);
+        room = roomFactory()(this, id,
+                joinState.omitted() ? JoinState::Join : joinState.value());
         if (!room)
         {
             qCCritical(MAIN) << "Failed to create a room" << id;
@@ -1010,6 +1020,9 @@ Room* Connection::provideRoom(const QString& id, JoinState joinState)
                 this, &Connection::aboutToDeleteRoom);
         emit newRoom(room);
     }
+    if (joinState.omitted())
+        return room;
+
     if (joinState == JoinState::Invite)
     {
         // prev is either Leave or nullptr
@@ -1018,7 +1031,7 @@ Room* Connection::provideRoom(const QString& id, JoinState joinState)
     }
     else
     {
-        room->setJoinState(joinState);
+        room->setJoinState(joinState.value());
         // Preempt the Invite room (if any) with a room in Join/Leave state.
         auto* prevInvite = d->roomMap.take({id, true});
         if (joinState == JoinState::Join)
diff --git a/lib/connection.h b/lib/connection.h
index ff3e2028..f2e10488 100644
--- a/lib/connection.h
+++ b/lib/connection.h
@@ -670,16 +670,27 @@ namespace QMatrixClient
              */
             const ConnectionData* connectionData() const;
 
-            /**
-             * @brief Find a (possibly new) Room object for the specified id
-             * Use this method whenever you need to find a Room object in
-             * the local list of rooms. Note that this does not interact with
-             * the server; in particular, does not automatically create rooms
-             * on the server.
-             * @return a pointer to a Room object with the specified id; nullptr
-             * if roomId is empty or roomFactory() failed to create a Room object.
-             */
-            Room* provideRoom(const QString& roomId, JoinState joinState);
+            /** Get a Room object for the given id in the given state
+             *
+             * Use this method when you need a Room object in the local list
+             * of rooms, with the given state. Note that this does not interact
+             * with the server; in particular, does not automatically create
+             * rooms on the server. This call performs necessary join state
+             * transitions; e.g., if it finds a room in Invite but
+             * `joinState == JoinState::Join` then the Invite room object
+             * will be deleted and a new room object with Join state created.
+             * In contrast, switching between Join and Leave happens within
+             * the same object.
+             * \param roomId room id (not alias!)
+             * \param joinState desired (target) join state of the room; if
+             * omitted, any state will be found and return unchanged, or a
+             * new Join room created.
+             * @return a pointer to a Room object with the specified id and the
+             * specified state; nullptr if roomId is empty or if roomFactory()
+             * failed to create a Room object.
+             */
+            Room* provideRoom(const QString& roomId,
+                              Omittable<JoinState> joinState = none);
 
             /**
              * Completes loading sync data.