List parent room name next to room names in room switcher

resources/qml/Completer.qml

@@ -249,6 +249,11 @@ Control {
                             text: model.roomName
                             textFormat: Text.RichText
                         }
+
+                        Label {
+                            text: model.roomParent === "" ? "" : ("[" + model.roomParent + "]")
+                            font.pixelSize: popup.avatarHeight * 0.5
+                        }
                     }
                 }
                 DelegateChoice {

src/Cache.cpp

@@ -26,6 +26,7 @@
 
 #include <nlohmann/json.hpp>
 
+#include <mtx/events/spaces.hpp>
 #include <mtx/responses/common.hpp>
 #include <mtx/responses/messages.hpp>
 
@@ -2945,6 +2946,26 @@ Cache::roomNamesAndAliases()
 {
     auto txn = ro_txn(env_);
 
+    auto getParentRoomIdsWithTxn = [&](const std::string &id) -> std::optional<std::string> {
+        auto cursor         = lmdb::cursor::open(txn, spacesParentsDb_);
+        std::string_view sp = id, space_parent;
+        if (cursor.get(sp, space_parent, MDB_SET)) {
+            while (cursor.get(sp, space_parent, MDB_FIRST_DUP)) {
+                if (!space_parent.empty())
+                    return std::make_optional(static_cast<std::string>(space_parent));
+            }
+        }
+        cursor.close();
+
+        return std::nullopt;
+    };
+
+    auto getRoomName = [&](const std::string &roomId) {
+        auto spaceDb = getStatesDb(txn, roomId);
+        auto membersDb = getMembersDb(txn, roomId);
+        return Cache::getRoomName(txn, spaceDb, membersDb).toStdString();
+    };
+
     std::vector<RoomNameAlias> result;
     result.reserve(roomsDb_.size(txn));
 
@@ -2962,6 +2983,15 @@ Cache::roomNamesAndAliases()
                 alias = aliases->content.alias;
             }
 
+            auto parentId = getParentRoomIdsWithTxn(room_id_str);
+            auto parentName = std::string{};
+
+            if (parentId) {
+                parentName = getRoomName(*parentId);
+            }
+
+            nhlog::db()->info("{} has parent [{}]", room_id_str, parentName);
+
             result.push_back(RoomNameAlias{
               .id              = std::move(room_id_str),
               .name            = std::move(info.name),
@@ -2969,6 +2999,7 @@ Cache::roomNamesAndAliases()
               .recent_activity = info.approximate_last_modification_ts,
               .is_tombstoned   = info.is_tombstoned,
               .is_space        = info.is_space,
+              .parent          = std::move(parentName),
             });
         } catch (std::exception &e) {
             nhlog::db()->warn("Failed to add room {} to result: {}", room_id, e.what());

src/CacheStructs.h

@@ -111,6 +111,7 @@ struct RoomNameAlias
     std::uint64_t recent_activity;
     bool is_tombstoned;
     bool is_space;
+    std::string parent;
 };
 
 //! Basic information per member.

src/RoomsModel.cpp

@@ -35,6 +35,7 @@ RoomsModel::roleNames() const
       {Roles::AvatarUrl, "avatarUrl"},
       {Roles::RoomID, "roomid"},
       {Roles::RoomName, "roomName"},
+      {Roles::RoomParent, "roomParent"},
       {Roles::IsTombstoned, "isTombstoned"},
       {Roles::IsSpace, "isSpace"},
     };
@@ -72,6 +73,8 @@ RoomsModel::data(const QModelIndex &index, int role) const
             return rooms[index.row()].is_tombstoned;
         case Roles::IsSpace:
             return rooms[index.row()].is_space;
+        case Roles::RoomParent:
+            return QString::fromStdString(rooms[index.row()].parent);
         }
     }
     return {};

src/RoomsModel.h

@@ -20,6 +20,7 @@ public:
         RoomName,
         IsTombstoned,
         IsSpace,
+        RoomParent,
     };
 
     RoomsModel(bool showOnlyRoomWithAliases = false, QObject *parent = nullptr);