[traffic] Make traffic initialization work with LoadMapsAsync()

Signed-off-by: mvglasow <michael -at- vonglasow.com>

map/framework.hpp

@@ -230,7 +230,34 @@ public:
   /// \note It works for group and leaf node.
   bool HasUnsavedEdits(storage::CountryId const & countryId);
 
+  /**
+   * @brief Loads maps synchronously.
+   *
+   * Maps are loaded on the calling thread.
+   *
+   * This function also performs certain initialization operations which depend on map data being
+   * available, such as search, traffic and the download queue.
+   *
+   * @note This function is not suitable for use on platforms which enforce restrictions on
+   * time-consuming or potentially blocking operations on the UI thread (as Android does). On such
+   * platforms, `LoadMapsAsync()` should be used instead.
+   */
   void LoadMapsSync();
+
+  /**
+   * @brief Loads maps asynchronously.
+   *
+   * Maps are loaded on a new thread. Some operations are executed as part of a separate task which
+   * is posted to the GUI thread.
+   *
+   * This function also performs certain initialization operations which depend on map data being
+   * available, such as search, traffic and the download queue.
+   *
+   * After finishing initialization, the caller-supplied callback function is called. This function
+   * also runs on the GUI thread and should therefore not perform any time-consuming operations.
+   *
+   * @param callback A callback function to run at the end of initialization.
+   */
   void LoadMapsAsync(std::function<void()> && callback);
 
   /// Registers all local map files in internal indexes.
@@ -389,6 +416,16 @@ private:
 private:
   std::vector<m2::TriangleD> GetSelectedFeatureTriangles() const;
 
+  /**
+   * @brief Initializes the traffic manager.
+   *
+   * This enables the traffic manager if defined in settings. If the traffic manager is not in test
+   * mode, all cunfigured sources are also added here.
+   *
+   * Maps must be loaded prior to calling this method.
+   */
+  void InitializeTraffic();
+
 public:
   /// @name GPS location updates routine.
   void OnLocationError(location::TLocationError error);