Scan for languages

src/debug.cpp

@@ -1279,9 +1279,10 @@ std::string game_info::game_report()
 
     std::string lang = get_option<std::string>( "USE_LANG" );
     std::string lang_translated;
-    for( const options_manager::id_and_option &vItem : options_manager::lang_options ) {
+    for( const options_manager::id_and_option &vItem : options_manager::actual_lang_options ) {
         if( vItem.first == lang ) {
             lang_translated = vItem.second.translated();
+            break;
         }
     }
 

src/options.cpp

@@ -58,25 +58,8 @@ bool tile_iso;
 std::map<std::string, std::string> TILESETS; // All found tilesets: <name, tileset_dir>
 std::map<std::string, std::string> SOUNDPACKS; // All found soundpacks: <name, soundpack_dir>
 
-std::vector<options_manager::id_and_option> options_manager::lang_options = {
-    { "", translate_marker( "System language" ) },
-    // Note: language names are in their own language and are *not* translated at all.
-    // Note: Somewhere in Github PR was better link to msdn.microsoft.com with language names.
-    // http://en.wikipedia.org/wiki/List_of_language_names
-    { "en", no_translation( R"(English)" ) },
-    { "de", no_translation( R"(Deutsch)" ) },
-    { "es_AR", no_translation( R"(Español (Argentina))" ) },
-    { "es_ES", no_translation( R"(Español (España))" ) },
-    { "fr", no_translation( R"(Français)" ) },
-    { "hu", no_translation( R"(Magyar)" ) },
-    { "ja", no_translation( R"(日本語)" ) },
-    { "ko", no_translation( R"(한국어)" ) },
-    { "pl", no_translation( R"(Polski)" ) },
-    { "pt_BR", no_translation( R"(Português (Brasil))" )},
-    { "ru", no_translation( R"(Русский)" ) },
-    { "zh_CN", no_translation( R"(中文 (天朝))" ) },
-    { "zh_TW", no_translation( R"(中文 (台灣))" ) },
-};
+const std::vector<options_manager::id_and_option> options_manager::actual_lang_options =
+    options_manager::get_actual_lang_options();
 
 options_manager &get_options()
 {
@@ -1035,6 +1018,57 @@ std::vector<options_manager::id_and_option> options_manager::build_soundpacks_li
     return result;
 }
 
+std::unordered_set<std::string> options_manager::get_lang_list()
+{
+    std::vector<std::string> lang_dirs = get_directories_with( PATH_INFO::lang_file(),
+                                         PATH_INFO::langdir(), true );
+    const std::string start_str = "mo/";
+    const std::size_t start_len = start_str.length();
+    const std::string end_str = "/LC_MESSAGES";
+    std::for_each( lang_dirs.begin(), lang_dirs.end(), [&]( std::string & dir ) {
+        const std::size_t start = dir.find( start_str ) + start_len;
+        const std::size_t len = dir.rfind( end_str ) - start;
+        dir = dir.substr( start, len );
+    } );
+    return std::unordered_set<std::string>( lang_dirs.begin(), lang_dirs.end() );
+}
+
+std::vector<options_manager::id_and_option> options_manager::get_actual_lang_options()
+{
+    std::vector<options_manager::id_and_option> lang_options = {
+        { "", translate_marker( "System language" ) },
+        // Note: language names are in their own language and are *not* translated at all.
+        // Note: Somewhere in Github PR was better link to msdn.microsoft.com with language names.
+        // http://en.wikipedia.org/wiki/List_of_language_names
+        { "en", no_translation( R"(English)" ) },
+        { "de", no_translation( R"(Deutsch)" ) },
+        { "es_AR", no_translation( R"(Español (Argentina))" ) },
+        { "es_ES", no_translation( R"(Español (España))" ) },
+        { "fr", no_translation( R"(Français)" ) },
+        { "hu", no_translation( R"(Magyar)" ) },
+        { "ja", no_translation( R"(日本語)" ) },
+        { "ko", no_translation( R"(한국어)" ) },
+        { "pl", no_translation( R"(Polski)" ) },
+        { "pt_BR", no_translation( R"(Português (Brasil))" )},
+        { "ru", no_translation( R"(Русский)" ) },
+        { "zh_CN", no_translation( R"(中文 (天朝))" ) },
+        { "zh_TW", no_translation( R"(中文 (台灣))" ) },
+    };
+
+    std::unordered_set<std::string> lang_list = options_manager::get_lang_list();
+
+    std::vector<options_manager::id_and_option> options;
+
+    lang_list.insert( "" ); // for System language option
+    lang_list.insert( "en" ); // for English option
+
+    std::copy_if( lang_options.begin(), lang_options.end(), std::back_inserter( options ),
+    [&lang_list]( const options_manager::id_and_option & pair ) {
+        return lang_list.count( pair.first );
+    } );
+    return options;
+}
+
 #if defined(__ANDROID__)
 bool android_get_default_setting( const char *settings_name, bool default_value )
 {
@@ -1330,9 +1364,8 @@ void options_manager::add_options_interface()
         interface_page_.items_.emplace_back();
     };
 
-    // TODO: scan for languages like we do for tilesets.
     add( "USE_LANG", "interface", translate_marker( "Language" ),
-         translate_marker( "Switch Language." ), options_manager::lang_options, "" );
+         translate_marker( "Switch Language." ), options_manager::actual_lang_options, "" );
 
     add_empty_line();
 

src/options.h

@@ -8,6 +8,7 @@
 #include <unordered_map>
 #include <utility>
 #include <vector>
+#include <unordered_set>
 #include <tuple>
 
 #include "translations.h"
@@ -29,14 +30,16 @@ class options_manager
                     : std::pair<std::string, translation>( first, second ) {
                 }
         };
-        static std::vector<id_and_option> lang_options;
+        static const std::vector<id_and_option> actual_lang_options;
     private:
         static std::vector<id_and_option> build_tilesets_list();
         static std::vector<id_and_option> build_soundpacks_list();
         static std::vector<id_and_option> load_tilesets_from(
             const std::string &path );
         static std::vector<id_and_option> load_soundpack_from(
             const std::string &path );
+        static std::unordered_set<std::string> get_lang_list();
+        static std::vector<id_and_option> get_actual_lang_options();
 
         bool load_legacy();
 

src/path_info.cpp

@@ -35,6 +35,7 @@ static std::string autopickup_value;
 static std::string keymap_value;
 static std::string options_value;
 static std::string memorialdir_value;
+static std::string langdir_value;
 
 void PATH_INFO::init_base_path( std::string path )
 {
@@ -82,13 +83,16 @@ void PATH_INFO::set_standard_filenames()
 #if defined(DATA_DIR_PREFIX)
         datadir_value = base_path_value + "share/cataclysm-dda/";
         gfxdir_value = datadir_value + "gfx/";
+        langdir_value = datadir_value + "lang/";
 #else
         datadir_value = base_path_value + "data/";
         gfxdir_value = base_path_value + "gfx/";
+        langdir_value = base_path_value + "lang/";
 #endif
     } else {
         datadir_value = "data/";
         gfxdir_value = "gfx/";
+        langdir_value = "lang/";
     }
 
     // Shared dirs
@@ -372,6 +376,14 @@ std::string PATH_INFO::gfxdir()
 {
     return gfxdir_value;
 }
+std::string PATH_INFO::langdir()
+{
+    return langdir_value;
+}
+std::string PATH_INFO::lang_file()
+{
+    return "cataclysm-dda.mo";
+}
 std::string PATH_INFO::data_sound()
 {
     return datadir_value + "sound";

src/path_info.h

@@ -57,6 +57,8 @@ std::string worldoptions();
 std::string crash();
 std::string tileset_conf();
 std::string gfxdir();
+std::string langdir();
+std::string lang_file();
 std::string user_gfx();
 std::string data_sound();
 std::string user_sound();