[gimp] Bug 576910: Show 'Language' setting languages in native language

[Jehan Pagès <jehanp src gnome org>]

commit f6dcde1ee66fda4dfdc063022c4d2e901adb9a71
Author: Jehan <jehan girinstud io>
Date:   Wed Jul 3 11:58:16 2013 +0900

    Bug 576910: Show 'Language' setting languages in native language
    
    The trick works by temporarily resetting the current locale to localize
    each language label in its own lang.
    One exception is English that is equivalent to the "C" code, and we make
    also some special exception for Chinese where there are very different
    variant depending on the region.
    I also ensure the "System Language" string is translated in whatever
    language is the system actually set to.

 app/widgets/gimplanguagestore-parser.c |   57 ++++++++++++++++++++++++++++++--
 app/widgets/gimptranslationstore.c     |   18 ++++++++--
 2 files changed, 68 insertions(+), 7 deletions(-)
---
diff --git a/app/widgets/gimplanguagestore-parser.c b/app/widgets/gimplanguagestore-parser.c
index 59c31ea..56f2c8e 100644
--- a/app/widgets/gimplanguagestore-parser.c
+++ b/app/widgets/gimplanguagestore-parser.c
@@ -67,6 +67,10 @@ static void  iso_codes_parser_end_element   (GMarkupParseContext  *context,
 static void  iso_codes_parser_start_unknown (IsoCodesParser       *parser);
 static void  iso_codes_parser_end_unknown   (IsoCodesParser       *parser);
 
+static void  gimp_language_store_self_l10n  (GimpLanguageStore *store,
+                                             const gchar       *lang,
+                                             const gchar       *code);
+
 
 static void
 iso_codes_parser_init (void)
@@ -160,11 +164,58 @@ iso_codes_parser_entry (IsoCodesParser  *parser,
       values++;
     }
 
+  /* This is a hack for some special exception.
+   * It seems localization won't work for the base language "zh". Probably because
+   * written locale dialect are too different. So we have to be accurate and localize
+   * separately each Chinese dialect we support.
+   *
+   * There was unfortunately no cleaner way to achieve this since there is no standardized
+   * link between regions in iso-3166 and base languages in iso-639, which would allow
+   * automatization for generating locale dialects codes.
+   */
+  if (g_strcmp0 (code, "zh") == 0)
+    {
+      gimp_language_store_self_l10n (parser->store, "Chinese", "zh_CN");
+      gimp_language_store_self_l10n (parser->store, "Chinese", "zh_TW");
+      gimp_language_store_self_l10n (parser->store, "Chinese", "zh_HK");
+    }
+  else
+    gimp_language_store_self_l10n (parser->store, lang, code);
+}
+
+/* If possible, we want to localize a language in itself.
+ * If it fails, fallback to the currently selected language, then to system lang.
+ * Only fallback to C (en_US) as a last resort.
+ */
+static void
+gimp_language_store_self_l10n (GimpLanguageStore *store,
+                               const gchar       *lang,
+                               const gchar       *code)
+{
   if (lang && *lang && code && *code)
     {
       const gchar *semicolon;
+      const gchar *current_lang = g_getenv ("LANGUAGE");
+
+      /* English does not need localization. */
+      if (g_strcmp0 (code, "en") != 0)
+        {
+          gchar       *temp_lang;
 
-      lang = dgettext ("iso_639", lang);
+          if (current_lang)
+            temp_lang = g_strdup_printf ("%s:%s:%s", code, current_lang, setlocale (LC_ALL, NULL));
+          else
+            temp_lang = g_strdup (code);
+
+          /* Temporarily change the localization language. */
+          g_setenv ("LANGUAGE", temp_lang, TRUE);
+          setlocale (LC_ALL, "");
+          lang = dgettext ("iso_639", lang);
+          g_setenv ("LANGUAGE", current_lang, TRUE);
+          setlocale (LC_ALL, "");
+
+          g_free (temp_lang);
+        }
 
       /*  there might be several language names; use the first one  */
       semicolon = strchr (lang, ';');
@@ -173,12 +224,12 @@ iso_codes_parser_entry (IsoCodesParser  *parser,
         {
           gchar *first = g_strndup (lang, semicolon - lang);
 
-          gimp_language_store_add (parser->store, first, code);
+          gimp_language_store_add (store, first, code);
           g_free (first);
         }
       else
         {
-          gimp_language_store_add (parser->store, lang, code);
+          gimp_language_store_add (store, lang, code);
         }
     }
 }
diff --git a/app/widgets/gimptranslationstore.c b/app/widgets/gimptranslationstore.c
index 8d1cf12..fee7c20 100644
--- a/app/widgets/gimptranslationstore.c
+++ b/app/widgets/gimptranslationstore.c
@@ -83,7 +83,8 @@ gimp_translation_store_init (GimpTranslationStore *store)
 static void
 gimp_translation_store_constructed (GObject *object)
 {
-  GimpTranslationStore *store = GIMP_TRANSLATION_STORE (object);
+  const gchar          *current_lang = g_getenv ("LANGUAGE");
+  GimpTranslationStore *store        = GIMP_TRANSLATION_STORE (object);
   gchar                *label;
 
   G_OBJECT_CLASS (parent_class)->constructed (object);
@@ -94,11 +95,20 @@ gimp_translation_store_constructed (GObject *object)
   g_hash_table_unref (store->map);
   store->map = NULL;
 
-  /*  add special entries for system locale and for "C"  */
+  /*  add special entries for system locale and for "C".
+   *  We want the system locale to be localized in itself. */
+  g_setenv ("LANGUAGE", setlocale (LC_ALL, NULL), TRUE);
+  setlocale (LC_ALL, "");
+  label = g_strdup_printf ("%s [%s]", _("System Language"),
+                           setlocale (LC_ALL, NULL));
+  g_setenv ("LANGUAGE", current_lang, TRUE);
+  setlocale (LC_ALL, "");
   GIMP_LANGUAGE_STORE_CLASS (parent_class)->add (GIMP_LANGUAGE_STORE (store),
-                                                 _("System Language"),
+                                                 label,
                                                  NULL);
-  label = g_strdup_printf ("%s [%s]", _("English"), "en_US");
+  g_free (label);
+
+  label = g_strdup_printf ("%s [%s]", "English", "en_US");
   GIMP_LANGUAGE_STORE_CLASS (parent_class)->add (GIMP_LANGUAGE_STORE (store),
                                                  label, "en_US");
   g_free (label);