Add an option to skip changing locale in the internat sample

Show that we can use the translations to the user language even without
changing the locale.

samples/internat/internat.cpp

@@ -57,7 +57,7 @@
 class MyApp: public wxApp
 {
 public:
-    MyApp() { m_lang = wxLANGUAGE_UNKNOWN; }
+    MyApp() { m_lang = wxLANGUAGE_UNKNOWN; m_setLocale = true; }
 
     virtual void OnInitCmdLine(wxCmdLineParser& parser) wxOVERRIDE;
     virtual bool OnCmdLineParsed(wxCmdLineParser& parser) wxOVERRIDE;
@@ -65,6 +65,7 @@ public:
 
 protected:
     wxLanguage m_lang;  // language specified by user
+    bool m_setLocale;   // if false, skip setting locale entirely
     wxLocale m_locale;  // locale we'll be using
 };
 
@@ -204,8 +205,14 @@ wxIMPLEMENT_APP(MyApp);
 // ----------------------------------------------------------------------------
 
 // command line arguments handling
+
+static const char* OPTION_NO_LOCALE = "no-locale";
+
 void MyApp::OnInitCmdLine(wxCmdLineParser& parser)
 {
+    parser.AddSwitch("n", OPTION_NO_LOCALE,
+                     _("skip setting locale on startup"));
+
     parser.AddParam(_("locale"),
                     wxCMD_LINE_VAL_STRING,
                     wxCMD_LINE_PARAM_OPTIONAL);
@@ -218,8 +225,20 @@ bool MyApp::OnCmdLineParsed(wxCmdLineParser& parser)
     if ( !wxApp::OnCmdLineParsed(parser) )
         return false;
 
+    if ( parser.Found(OPTION_NO_LOCALE) )
+    {
+        m_setLocale = false;
+    }
+
     if ( parser.GetParamCount() )
     {
+        if ( !m_setLocale )
+        {
+            wxLogError("Locale parameter ignored when %s option is used.",
+                       OPTION_NO_LOCALE);
+            return false;
+        }
+
         const wxString loc = parser.GetParam();
         if ( loc.empty() )
         {
@@ -247,18 +266,26 @@ bool MyApp::OnInit()
     if ( !wxApp::OnInit() )
         return false;
 
+    if ( m_setLocale )
+    {
         if ( m_lang == wxLANGUAGE_UNKNOWN )
         {
             int lng = wxGetSingleChoiceIndex
                       (
-                    _("Please choose language:"),
+                        "Please choose a language or cancel to skip changing it:",
-                    _("Language"),
+                        "Language",
                         WXSIZEOF(langNames),
                         langNames
                       );
-        m_lang = lng == -1 ? wxLANGUAGE_DEFAULT : langIds[lng];
+            if ( lng == -1 )
+                m_setLocale = false;
+            else
+                m_lang = langIds[lng];
+        }
     }
 
+    if ( m_setLocale )
+    {
         // don't use wxLOCALE_LOAD_DEFAULT flag so that Init() doesn't return
         // false just because it failed to load wxstd catalog
         if ( !m_locale.Init(m_lang, wxLOCALE_DONT_LOAD_DEFAULT) )
@@ -267,6 +294,7 @@ bool MyApp::OnInit()
 
             // continue nevertheless
         }
+    }
 
     // normally this wouldn't be necessary as the catalog files would be found
     // in the default locations, but when the program is not installed the