Allow getting all usable translations languages

Add a method to return the full list of translations that can be used,
generalizing the existing GetBestTranslation().

include/wx/translation.h

@@ -145,6 +145,11 @@ public:
     wxString GetBestTranslation(const wxString& domain,
                                 const wxString& msgIdLanguage = "en");
 
+    // find best and all other suitable translation languages for given domain
+    wxArrayString GetAllGoodTranslations(const wxString& domain, wxLanguage msgIdLanguage);
+    wxArrayString GetAllGoodTranslations(const wxString& domain,
+                                const wxString& msgIdLanguage = "en");
+
     // add standard wxWidgets catalog ("wxstd")
     bool AddStdCatalog();
 

interface/wx/translation.h

@@ -137,6 +137,49 @@ public:
                                 const wxString& msgIdLanguage = "en");
 
     /**
+        Returns the best and all other suitable UI languages for the @a domain.
+
+        This is nearly the same as GetBestTranslation(), but returns the
+        whole list of preferred UI languages for which a translation for the
+        @a domain was found.
+
+        @param domain
+            The catalog domain to look for.
+
+        @param msgIdLanguage
+            Specifies the language of "msgid" strings in source code
+            (i.e. arguments to GetString(), wxGetTranslation() and the _() macro).
+
+        @return An array of language codes if any suitable matches were found, empty array
+                otherwise.
+
+        @since 3.1.2
+     */
+    wxArrayString GetAllGoodTranslations(const wxString& domain, wxLanguage msgIdLanguage);
+
+    /**
+        Returns the best and all other suitable UI languages for the @a domain.
+
+        This is nearly the same as GetBestTranslation(), but returns the
+        whole list of preferred UI languages for which a translation for the
+        @a domain was found.
+
+        @param domain
+            The catalog domain to look for.
+
+        @param msgIdLanguage
+            Specifies the language of "msgid" strings in source code
+            (i.e. arguments to GetString(), wxGetTranslation() and the _() macro).
+
+        @return An array of language codes if any suitable matches were found, empty array
+                otherwise.
+
+        @since 3.1.2
+     */
+        wxArrayString GetAllGoodTranslations(const wxString& domain,
+                                const wxString& msgIdLanguage = "en");
+
+        /**
         Add standard wxWidgets catalogs ("wxstd" and possible port-specific
         catalogs).
 

src/common/translation.cpp

@@ -127,7 +127,7 @@ wxString GetPreferredUILanguageFallback(const wxArrayString& WXUNUSED(available)
 
 #ifdef __WINDOWS__
 
-wxString GetPreferredUILanguage(const wxArrayString& available)
+wxString GetPreferredUILanguage(const wxArrayString& available, wxArrayString& allPreferred)
 {
     typedef BOOL (WINAPI *GetUserPreferredUILanguages_t)(DWORD, PULONG, PWSTR, PULONG);
     static GetUserPreferredUILanguages_t s_pfnGetUserPreferredUILanguages = NULL;
@@ -172,18 +172,20 @@ wxString GetPreferredUILanguage(const wxArrayString& available)
                     wxString lang(*j);
                     lang.Replace("-", "_");
                     if ( available.Index(lang, /*bCase=*/false) != wxNOT_FOUND )
-                        return lang;
+                        allPreferred.Add(lang);
                     size_t pos = lang.find('_');
                     if ( pos != wxString::npos )
                     {
                         lang = lang.substr(0, pos);
                         if ( available.Index(lang, /*bCase=*/false) != wxNOT_FOUND )
-                            return lang;
+                            allPreferred.Add(lang);
                     }
                 }
             }
         }
     }
+    if ( !allPreferred.empty() )
+        return allPreferred[0];
 
     return GetPreferredUILanguageFallback(available);
 }
@@ -207,7 +209,7 @@ void LogTraceArray(const char *prefix, CFArrayRef arr)
 
 #endif // wxUSE_LOG_TRACE
 
-wxString GetPreferredUILanguage(const wxArrayString& available)
+wxString GetPreferredUILanguage(const wxArrayString& available, wxArrayString &allPreferred)
 {
     wxStringToStringHashMap availableNormalized;
     wxCFRef<CFMutableArrayRef> availableArr(
@@ -231,17 +233,19 @@ wxString GetPreferredUILanguage(const wxArrayString& available)
     LogTraceArray(" - system preferred languages", prefArr);
 
     unsigned prefArrLength = CFArrayGetCount(prefArr);
-    if ( prefArrLength > 0 )
+    for ( size_t x = 0; x < prefArrLength; ++x )
     {
         // Lookup the name in 'available' by index -- we need to get the
         // original value corresponding to the normalized one chosen.
-        wxString lang(wxCFStringRef::AsString((CFStringRef)CFArrayGetValueAtIndex(prefArr, 0)));
+        wxString lang(wxCFStringRef::AsString((CFStringRef)CFArrayGetValueAtIndex(prefArr, x)));
         wxStringToStringHashMap::const_iterator i = availableNormalized.find(lang);
         if ( i == availableNormalized.end() )
-            return lang;
+            allPreferred.push_back(lang);
         else
-            return i->second;
+            allPreferred.push_back(i->second);
     }
+    if ( allPreferred.empty() == false )
+        return allPreferred[0];
 
     return GetPreferredUILanguageFallback(available);
 }
@@ -255,7 +259,7 @@ wxString GetPreferredUILanguage(const wxArrayString& available)
 // The LANGUAGE variable may contain a colon separated list of language
 // codes in the order of preference.
 // http://www.gnu.org/software/gettext/manual/html_node/The-LANGUAGE-variable.html
-wxString GetPreferredUILanguage(const wxArrayString& available)
+wxString GetPreferredUILanguage(const wxArrayString& available, wxArrayString &allPreferred)
 {
     wxString languageFromEnv;
     wxArrayString preferred;
@@ -283,15 +287,17 @@ wxString GetPreferredUILanguage(const wxArrayString& available)
     {
         wxString lang(*j);
         if ( available.Index(lang) != wxNOT_FOUND )
-            return lang;
+            allPreferred.Add(lang);
         size_t pos = lang.find('_');
         if ( pos != wxString::npos )
         {
             lang = lang.substr(0, pos);
             if ( available.Index(lang) != wxNOT_FOUND )
-                return lang;
+                allPreferred.Add(lang);
         }
     }
+    if ( allPreferred.empty() == false )
+        return allPreferred[0];
 
     return GetPreferredUILanguageFallback(available);
 }
@@ -1650,20 +1656,37 @@ wxString wxTranslations::GetBestTranslation(const wxString& domain,
 wxString wxTranslations::GetBestTranslation(const wxString& domain,
                                             const wxString& msgIdLanguage)
 {
-    // explicitly set language should always be respected
+    const wxArrayString allGoodOnes = GetAllGoodTranslations(domain, msgIdLanguage);
-    if ( !m_lang.empty() )
-        return m_lang;
 
+    wxLogTrace(TRACE_I18N, " => using language '%s'", allGoodOnes[0]);
+    return allGoodOnes[0];
+}
+
+wxArrayString wxTranslations::GetAllGoodTranslations(const wxString& domain,
+                                                       wxLanguage msgIdLanguage)
+{
+    const wxString lang = wxLocale::GetLanguageCanonicalName(msgIdLanguage);
+    return GetAllGoodTranslations(domain, lang);
+}
+
+wxArrayString wxTranslations::GetAllGoodTranslations(const wxString& domain,
+                                                       const wxString& msgIdLanguage)
+{
     wxArrayString available(GetAvailableTranslations(domain));
     // it's OK to have duplicates, so just add msgid language
     available.push_back(msgIdLanguage);
     available.push_back(msgIdLanguage.BeforeFirst('_'));
 
-    wxLogTrace(TRACE_I18N, "choosing best language for domain '%s'", domain);
+    wxLogTrace(TRACE_I18N, "choosing best languages for domain '%s'", domain);
     LogTraceArray(" - available translations", available);
-    const wxString lang = GetPreferredUILanguage(available);
+    wxArrayString allPreferred;
-    wxLogTrace(TRACE_I18N, " => using language '%s'", lang);
+    GetPreferredUILanguage(available, allPreferred);
-    return lang;
+
+    // explicitly set language should always be preferred the most
+    if ( !m_lang.empty() )
+        allPreferred.insert(allPreferred.begin(), m_lang);
+
+    return allPreferred;
 }