added static convertTo...() methods

Standalone conversions from Locale and LangID do not need a LanguageTag
instance. Provide simple static methods. For consistency also static
methods to convert from BCP47, but using a temporary instance.

Change-Id: I5edd27e917ef9e92e8ec457e715b7558d7e4660f

2 files changed, 174 insertions, 20 deletions

diff --git a/i18nlangtag/source/languagetag/languagetag.cxx b/i18nlangtag/source/languagetag/languagetag.cxx
index c1319dd70b51..d35f82fe1407 100644
--- a/i18nlangtag/source/languagetag/languagetag.cxx
+++ b/i18nlangtag/source/languagetag/languagetag.cxx
@@ -616,17 +616,7 @@ void LanguageTag::convertLocaleToBcp47()
     }
     else
     {
-        /* XXX NOTE: most legacy code never evaluated the Variant field, so for
-         * now just concatenate language and country. In case we stumbled over
-         * variant aware code we'd have to take care of that. */
-        if (maLocale.Country.isEmpty())
-            maBcp47 = maLocale.Language;
-        else
-        {
-            OUStringBuffer aBuf( maLocale.Language.getLength() + 1 + maLocale.Country.getLength());
-            aBuf.append( maLocale.Language).append( '-').append( maLocale.Country);
-            maBcp47 = aBuf.makeStringAndClear();
-        }
+        maBcp47 = convertToBcp47( maLocale, true);
     }
     mbInitializedBcp47 = true;
 }
@@ -640,10 +630,7 @@ void LanguageTag::convertLocaleToLang()
     }
     else
     {
-        /* FIXME: this is temporary until code base is converted to not use
-         * MsLangId::convert...() anymore. After that, proper new method has to
-         * be implemented to allow I18NLANGTAG_QLT and sript tag and such. */
-        mnLangID = MsLangId::Conversion::convertLocaleToLanguage( maLocale);
+        mnLangID = convertToLanguageType( maLocale, true);
     }
     mbInitializedLangID = true;
 }
@@ -694,11 +681,8 @@ void LanguageTag::convertLangToLocale()
         mnLangID = MsLangId::getRealLanguage( LANGUAGE_SYSTEM);
         mbInitializedLangID = true;
     }
-    /* FIXME: this is temporary until code base is converted to not use
-     * MsLangId::convert...() anymore. After that, proper new method has to be
-     * implemented to allow I18NLANGTAG_QLT and script tag and such. */
-    // Resolve system here!
-    maLocale = MsLangId::Conversion::convertLanguageToLocale( mnLangID, true);
+    // Resolve system here! The original is remembered as mbSystemLocale.
+    maLocale = convertToLocale( mnLangID, true);
     mbInitializedLocale = true;
 }
 
@@ -1374,4 +1358,106 @@ LanguageTag::Extraction LanguageTag::simpleExtract( const OUString& rBcp47,
     return rList.end();
 }
 
+
+static bool lcl_isSystem( LanguageType nLangID )
+{
+    if (nLangID == LANGUAGE_SYSTEM)
+        return true;
+    // There are some special values that simplify to SYSTEM,
+    // getRealLanguage() catches and resolves them.
+    LanguageType nNewLangID = MsLangId::getRealLanguage( nLangID);
+    if (nNewLangID != nLangID)
+        return true;
+    return false;
+}
+
+
+// static
+com::sun::star::lang::Locale LanguageTag::convertToLocale( LanguageType nLangID, bool bResolveSystem )
+{
+    if (!bResolveSystem && lcl_isSystem( nLangID))
+        return lang::Locale();
+
+    /* FIXME: this is temporary until code base is converted to not use
+     * MsLangId::convert...() anymore. After that, proper new method has to be
+     * implemented to allow I18NLANGTAG_QLT and script tag and such. */
+    return MsLangId::Conversion::convertLanguageToLocale( nLangID, bResolveSystem);
+}
+
+
+// static
+LanguageType LanguageTag::convertToLanguageType( const com::sun::star::lang::Locale& rLocale, bool bResolveSystem )
+{
+    if (rLocale.Language.isEmpty() && !bResolveSystem)
+        return LANGUAGE_SYSTEM;
+
+    /* FIXME: this is temporary until code base is converted to not use
+     * MsLangId::convert...() anymore. After that, proper new method has to
+     * be implemented to allow I18NLANGTAG_QLT and sript tag and such. */
+    return MsLangId::Conversion::convertLocaleToLanguage( rLocale);
+}
+
+
+// static
+OUString LanguageTag::convertToBcp47( const com::sun::star::lang::Locale& rLocale, bool bResolveSystem )
+{
+    OUString aBcp47;
+    if (rLocale.Language.isEmpty())
+    {
+        if (bResolveSystem)
+            aBcp47 = convertToBcp47( LANGUAGE_SYSTEM, true);
+        // else aBcp47 stays empty
+    }
+    else if (rLocale.Language == I18NLANGTAG_QLT)
+    {
+        aBcp47 = rLocale.Variant;
+    }
+    else
+    {
+        /* XXX NOTE: most legacy code never evaluated the Variant field, so for
+         * now just concatenate language and country. In case we stumbled over
+         * variant aware code we'd have to take care of that. */
+        if (rLocale.Country.isEmpty())
+            aBcp47 = rLocale.Language;
+        else
+        {
+            OUStringBuffer aBuf( rLocale.Language.getLength() + 1 + rLocale.Country.getLength());
+            aBuf.append( rLocale.Language).append( '-').append( rLocale.Country);
+            aBcp47 = aBuf.makeStringAndClear();
+        }
+    }
+    return aBcp47;
+}
+
+
+// static
+OUString LanguageTag::convertToBcp47( LanguageType nLangID, bool bResolveSystem )
+{
+    // Catch this first so we don't need the rest.
+    if (!bResolveSystem && lcl_isSystem( nLangID))
+        return OUString();
+
+    lang::Locale aLocale( convertToLocale( nLangID, bResolveSystem));
+    // If system for some reason (should not happen.. haha) could not be
+    // resolved DO NOT CALL convertToBcp47() because that would recurse into
+    // this method here!
+    if (aLocale.Language.isEmpty() && bResolveSystem)
+        return OUString();      // bad luck, bail out
+    return convertToBcp47( aLocale, bResolveSystem);
+}
+
+
+// static
+com::sun::star::lang::Locale LanguageTag::convertToLocale( const OUString& rBcp47, bool bResolveSystem )
+{
+    return LanguageTag( rBcp47).getLocale( bResolveSystem);
+}
+
+
+// static
+LanguageType LanguageTag::convertToLanguageType( const OUString& rBcp47, bool bResolveSystem )
+{
+    return LanguageTag( rBcp47).getLanguageType( bResolveSystem);
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */
diff --git a/include/i18nlangtag/languagetag.hxx b/include/i18nlangtag/languagetag.hxx
index bbda176a8f20..1a1d69deaae6 100644
--- a/include/i18nlangtag/languagetag.hxx
+++ b/include/i18nlangtag/languagetag.hxx
@@ -41,6 +41,9 @@ typedef struct _rtl_Locale rtl_Locale;  // as in rtl/locale.h
     Note that member variables are mutable and may change their values even in
     const methods. Getter methods return either the original value or matching
     converted values.
+
+    For standalone conversions if no LanguageTag instance is at hand, static
+    convertTo...() methods exist.
  */
 class I18NLANGTAG_DLLPUBLIC LanguageTag
 {
@@ -365,6 +368,71 @@ public:
      */
     bool    operator!=( const LanguageTag & rLanguageTag ) const;
 
+
+    /** Convert MS-LangID to Locale.
+
+        @param bResolveSystem
+               If TRUE, resolve an empty language tag denoting the system
+               locale to the real locale used.
+               If FALSE, return an empty Locale for such a tag.
+     */
+    static com::sun::star::lang::Locale convertToLocale( LanguageType nLangID, bool bResolveSystem = true );
+
+    /** Convert Locale to MS-LangID.
+
+        @param bResolveSystem
+               If TRUE, resolve an empty language tag denoting the system
+               locale to the real locale used.
+               If FALSE, return LANGUAGE_SYSTEM for such a tag.
+     */
+    static LanguageType convertToLanguageType( const com::sun::star::lang::Locale& rLocale, bool bResolveSystem = true );
+
+    /** Convert MS-LangID to BCP 47 string.
+
+        @param bResolveSystem
+               If TRUE, resolve an empty language tag denoting the system
+               locale to the real locale used.
+               If FALSE, return an empty OUString for such a tag.
+     */
+    static OUString convertToBcp47( LanguageType nLangID, bool bResolveSystem = true );
+
+    /** Convert Locale to BCP 47 string.
+
+        @param bResolveSystem
+               If TRUE, resolve an empty language tag denoting the system
+               locale to the real locale used.
+               If FALSE, return an empty OUString for such a tag.
+     */
+    static OUString convertToBcp47( const com::sun::star::lang::Locale& rLocale, bool bResolveSystem = true );
+
+    /** Convert BCP 47 string to Locale, convenience method.
+
+        NOTE: exists only for consistency with the other convertTo...()
+        methods, internally uses a temporary LanguageTag instance for
+        conversion so does not save anything compared to
+        LanguageTag(rBcp47).getLocale(bResolveSystem).
+
+        @param bResolveSystem
+               If TRUE, resolve an empty language tag denoting the system
+               locale to the real locale used.
+               If FALSE, return an empty Locale for such a tag.
+     */
+    static com::sun::star::lang::Locale convertToLocale( const OUString& rBcp47, bool bResolveSystem = true );
+
+    /** Convert BCP 47 string to MS-LangID, convenience method.
+
+        NOTE: exists only for consistency with the other convertTo...()
+        methods, internally uses a temporary LanguageTag instance for
+        conversion so does not save anything compared to
+        LanguageTag(rBcp47).getLanguageType(bResolveSystem).
+
+        @param bResolveSystem
+               If TRUE, resolve an empty language tag denoting the system
+               locale to the real locale used.
+               If FALSE, return LANGUAGE_SYSTEM for such a tag.
+     */
+    static LanguageType convertToLanguageType( const OUString& rBcp47, bool bResolveSystem = true );
+
 private:
 
     enum Decision