Get user preferred languages on 1st startup and use them for text dislpaying

@TODO windows implementation

map/languages.cpp

@@ -10,6 +10,7 @@
 #include "../coding/multilang_utf8_string.hpp"
 
 #include "../platform/platform.hpp"
+#include "../platform/preferred_languages.hpp"
 
 #include "../std/algorithm.hpp"
 #include "../std/sstream.hpp"
@@ -96,8 +97,9 @@ namespace languages
   void GetCurrentSettings(CodesAndNamesT & outLanguages)
   {
     string settingsString;
+    // get preffered languages from the system
     if (!Settings::Get(SETTING_LANG_KEY, settingsString))
-      settingsString = DEFAULT_LANGUAGES; // @TODO get preffered languages from the system
+      settingsString = languages::PreferredLanguages();
 
     CodesT currentCodes;
     Collector c(currentCodes);
@@ -133,4 +135,5 @@ namespace languages
     }
     return !outLanguages.empty();
   }
+
 }

platform/platform.pro

@@ -50,6 +50,8 @@ HEADERS += \
     download_manager.hpp \
     location.hpp \
     concurrent_runner.hpp \
+    preferred_languages.hpp \
 
 SOURCES += \
     location_manager.cpp \
+    preferred_languages.cpp \

platform/platform_tests/language_test.cpp

@@ -0,0 +1,36 @@
+#include "../../testing/testing.hpp"
+
+#include "../../std/string.hpp"
+#include "../../std/vector.hpp"
+
+namespace languages
+{
+  void FilterLanguages(vector<string> & langs);
+}
+
+UNIT_TEST(LangFilter)
+{
+  vector<string> v;
+  v.push_back("en");
+  v.push_back("en-GB");
+  v.push_back("zh");
+  v.push_back("es-SP");
+  v.push_back("zh-penyn");
+  v.push_back("en-US");
+  v.push_back("ru_RU");
+  v.push_back("es");
+
+  languages::FilterLanguages(v);
+
+  vector<string> c;
+  c.push_back("en");
+  c.push_back("zh");
+  c.push_back("es");
+  c.push_back("ru");
+
+  TEST_EQUAL(v.size(), c.size(), (v, c));
+  for (size_t i = 0; i < c.size(); ++i)
+  {
+    TEST_EQUAL(c[i], v[i], (v, c));
+  }
+}

platform/platform_tests/platform_tests.pro

@@ -27,3 +27,4 @@ SOURCES += \
     download_test.cpp \
     jansson_test.cpp \
     concurrent_runner_test.cpp \
+    language_test.cpp \

platform/preferred_languages.cpp

@@ -0,0 +1,114 @@
+#include "preferred_languages.hpp"
+
+#include "../base/string_utils.hpp"
+#include "../base/logging.hpp"
+
+#include "../std/target_os.hpp"
+#include "../std/set.hpp"
+
+#if defined(OMIM_OS_MAC) || defined(OMIM_OS_IPHONE)
+  #include <CoreFoundation/CFLocale.h>
+  #include <CoreFoundation/CFString.h>
+
+#elif defined(OMIM_OS_WINDOWS)
+  // @TODO
+
+#else
+  #error "Define language preferences for your platform"
+
+#endif
+
+namespace languages
+{
+
+class LangFilter
+{
+  set<string> & m_known;
+public:
+  LangFilter(set<string> & known) : m_known(known) {}
+  bool operator()(string const & t)
+  {
+    return !m_known.insert(t).second;
+  }
+};
+
+class NormalizeFilter
+{
+public:
+  void operator()(string & t)
+  {
+    strings::SimpleTokenizer const iter(t, "-_ ");
+    if (iter)
+      t = *iter;
+    else
+    {
+      LOG(LWARNING, ("Invalid language"));
+    }
+  }
+};
+
+void FilterLanguages(vector<string> & langs)
+{
+  // normalize languages: en-US -> en, ru_RU -> ru etc.
+  for_each(langs.begin(), langs.end(), NormalizeFilter());
+  { // tmp storage
+    set<string> known;
+    // remove duplicate languages
+    langs.erase(remove_if(langs.begin(), langs.end(), LangFilter(known)), langs.end());
+  }
+}
+
+void SystemPreferredLanguages(vector<string> & languages)
+{
+#if defined(OMIM_OS_MAC) || defined(OMIM_OS_IPHONE)
+  // Mac and iOS implementation
+  CFArrayRef langs = CFLocaleCopyPreferredLanguages();
+  char buf[30];
+  for (CFIndex i = 0; i < CFArrayGetCount(langs); ++i)
+  {
+    CFStringRef strRef = (CFStringRef)CFArrayGetValueAtIndex(langs, i);
+    CFStringGetCString(strRef, buf, 30, kCFStringEncodingUTF8);
+    languages.push_back(buf);
+  }
+  CFRelease(langs);
+
+#elif defined(OMIM_OS_WINDOWS)
+  // @TODO Windows implementation
+#else
+  #error "Define language preferences for your platform"
+#endif
+
+  FilterLanguages(languages);
+}
+
+string PreferredLanguages()
+{
+  vector<string> arr;
+
+  SystemPreferredLanguages(arr);
+
+  // generate output string
+  string result;
+  for (size_t i = 0; i < arr.size(); ++i)
+  {
+    result.append(arr[i]);
+    result.push_back('|');
+  }
+  if (result.empty())
+    result = "default";
+  else
+    result.resize(result.size() - 1);
+  return result;
+}
+
+string CurrentLanguage()
+{
+  vector<string> arr;
+  SystemPreferredLanguages(arr);
+  if (arr.empty())
+    return "en";
+  else
+    return arr[0];
+}
+
+}

platform/preferred_languages.hpp

@@ -0,0 +1,13 @@
+#pragma once
+
+#include "../std/string.hpp"
+
+namespace languages
+{
+
+/// @return system language preferences in the form "en|ru|es|zh"
+string PreferredLanguages();
+/// @return language code for current user in the form "en"
+string CurrentLanguage();
+
+}