[new downloader] Implementation functionality for calculation a limit rect for leaf and not leaf node.

storage/storage_helpers.cpp

@@ -3,9 +3,29 @@
 #include "storage/country_info_getter.hpp"
 #include "storage/storage.hpp"
 
+namespace
+{
+using namespace storage;
+
+class CalcLimitRectAccumulator
+{
+  m2::RectD m_boundBox;
+ CountryInfoGetter const & m_countryInfoGetter;
+public:
+  CalcLimitRectAccumulator(CountryInfoGetter const & countryInfoGetter)
+    : m_countryInfoGetter(countryInfoGetter) {}
+
+  m2::RectD GetBoundBox() { return m_boundBox; }
+  void operator()(TCountryId const & descendantCountryId, bool expandableNode)
+  {
+    if (!expandableNode)
+      m_boundBox.Add(m_countryInfoGetter.CalcLimitRectForLeaf(descendantCountryId));
+  }
+};
+} // namespace
+
 namespace storage
 {
-
 bool IsPointCoveredByDownloadedMaps(m2::PointD const & position,
                                     Storage const & storage,
                                     CountryInfoGetter const & countryInfoGetter)
@@ -18,4 +38,17 @@ bool IsDownloadFailed(Status status)
   return status == Status::EDownloadFailed || status == Status::EOutOfMemFailed ||
          status == Status::EUnknown;
 }
+
+m2::RectD CalcLimitRect(TCountryId countryId,
+                        Storage const & storage,
+                        CountryInfoGetter const & countryInfoGetter)
+{
+  CalcLimitRectAccumulator accumulater(countryInfoGetter);
+  storage.ForEachInSubtree(countryId, accumulater);
+  m2::RectD const boundBox = accumulater.GetBoundBox();
+
+  ASSERT(boundBox.IsValid(), ());
+
+  return accumulater.GetBoundBox();
+}
 } // namespace storage

storage/storage_helpers.hpp

@@ -1,8 +1,10 @@
 #pragma once
 
 #include "geometry/point2d.hpp"
+#include "geometry/rect2d.hpp"
 
-#include "storage_defines.hpp"
+#include "storage/index.hpp"
+#include "storage/storage_defines.hpp"
 
 namespace storage
 {
@@ -17,4 +19,10 @@ bool IsPointCoveredByDownloadedMaps(m2::PointD const & position,
                                     CountryInfoGetter const & countryInfoGetter);
 
 bool IsDownloadFailed(Status status);
+
+/// \brief Calculates limit rect for |countryId| (non expandable or not).
+/// \returns bound box in mercator coordinates.
+m2::RectD CalcLimitRect(TCountryId countryId,
+                        Storage const & storage,
+                        CountryInfoGetter const & countryInfoGetter);
 } // namespace storage