Use GLib to parse environment variables to determine the default locale.

Switch to using GLib, instead of having a Chromium specific implementation, for
parsing environment variables for language preferences for all POSIX systems
that use GTK+. If we have a non-GTK port in the future, we have to resurrect
our custom code.

This will guarantee that UI language selection in Chromium works just like for
all other GTK+ applications, and simplify the code.

While doing this, also do some cleaning-up of the language preferences code and
add a test case to verify that the prioritization is done correctly.

Original CL by Fredrik Roubert at http://codereview.chromium.org/2901004/show

BUG=NONE
TEST=app_unittest with "--gtest_filter=L10nUt*.*Loc*" passes.

Review URL: http://codereview.chromium.org/4217004

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@64524 0039d316-1c4b-4281-b951-d872f2087c98

2 files changed, 53 insertions, 10 deletions

diff --git a/base/i18n/rtl.cc b/base/i18n/rtl.cc
index f5381a2..9ff12d8 100644
--- a/base/i18n/rtl.cc
+++ b/base/i18n/rtl.cc
@@ -18,25 +18,57 @@
 #include <gtk/gtk.h>
 #endif
 
+namespace {
+
+// Extract language and country, ignore keywords, concatenate using dash.
+std::string GetLocaleString(const icu::Locale& locale) {
+  const char* language = locale.getLanguage();
+  const char* country = locale.getCountry();
+
+  std::string result =
+      (language != NULL && *language != '\0') ? language : "und";
+
+  if (country != NULL && *country != '\0') {
+    result += '-';
+    result += country;
+  }
+
+  return result;
+}
+
+}  // namespace
+
 namespace base {
 namespace i18n {
 
 // Represents the locale-specific ICU text direction.
 static TextDirection g_icu_text_direction = UNKNOWN_DIRECTION;
 
+#if defined(OS_WIN)
 void GetLanguageAndRegionFromOS(std::string* lang, std::string* region) {
   // Later we may have to change this to be OS-dependent so that
   // it's not affected by ICU's default locale. It's all right
   // to do this way because SetICUDefaultLocale is internal
   // to this file and we know that it's not yet called when this function
   // is called.
-  icu::Locale locale = icu::Locale::getDefault();
+  const icu::Locale& locale = icu::Locale::getDefault();
   const char* language = locale.getLanguage();
   const char* country = locale.getCountry();
   DCHECK(language);
   *lang = language;
   *region = country;
 }
+#endif
+
+// Convert the ICU default locale to a string.
+std::string GetConfiguredLocale() {
+  return GetLocaleString(icu::Locale::getDefault());
+}
+
+// Convert the ICU canonicalized locale to a string.
+std::string GetCanonicalLocale(const char* locale) {
+  return GetLocaleString(icu::Locale::createCanonical(locale));
+}
 
 // Convert Chrome locale name to ICU locale name
 std::string ICULocaleName(const std::string& locale_string) {
@@ -50,13 +82,14 @@ std::string ICULocaleName(const std::string& locale_string) {
   // locale.  If it's es-RR other than es-ES, map to es-RR. Otherwise, map
   // to es-MX (the most populous in Spanish-speaking Latin America).
   if (LowerCaseEqualsASCII(locale_string, "es-419")) {
-    std::string lang, region;
-    GetLanguageAndRegionFromOS(&lang, &region);
-    if (LowerCaseEqualsASCII(lang, "es") &&
-      !LowerCaseEqualsASCII(region, "es")) {
-        lang.append("-");
-        lang.append(region);
-        return lang;
+    const icu::Locale& locale = icu::Locale::getDefault();
+    std::string language = locale.getLanguage();
+    const char* country = locale.getCountry();
+    if (LowerCaseEqualsASCII(language, "es") &&
+      !LowerCaseEqualsASCII(country, "es")) {
+        language += '-';
+        language += country;
+        return language;
     }
     return "es-MX";
   }
diff --git a/base/i18n/rtl.h b/base/i18n/rtl.h
index 2fe932c..52b1a2b 100644
--- a/base/i18n/rtl.h
+++ b/base/i18n/rtl.h
@@ -29,8 +29,18 @@ enum TextDirection {
   LEFT_TO_RIGHT,
 };
 
-// Get language and region from the OS.
+#if defined(OS_WIN)
+// Get language and region from the OS. Used by Chrome Frame.
 void GetLanguageAndRegionFromOS(std::string* lang, std::string* region);
+#endif
+
+// Get the locale that the currently running process has been configured to use.
+// The return value is of the form language[-country] (e.g., en-US) where the
+// language is the 2 or 3 letter code from ISO-639.
+std::string GetConfiguredLocale();
+
+// Canonicalize a string (eg. a POSIX locale string) to a Chrome locale name.
+std::string GetCanonicalLocale(const char* locale);
 
 // Sets the default locale of ICU.
 // Once the application locale of Chrome in GetApplicationLocale is determined,
@@ -136,7 +146,7 @@ void WrapPathWithLTRFormatting(const FilePath& path,
 // string is wrapped with LRE (Left-To-Right Embedding) and PDF (Pop
 // Directional Formatting) marks and returned. In LTR locale, the string itself
 // is returned.
-string16 GetDisplayStringInLTRDirectionality(const string16& text) 
+string16 GetDisplayStringInLTRDirectionality(const string16& text)
     WARN_UNUSED_RESULT;
 
 // Strip the beginning (U+202A..U+202B, U+202D..U+202E) and/or ending (U+202C)