added getMatchingFallback()

Change-Id: I5805ab98049bd7dfd8ca1b58632f6c0115197bdd

i18nlangtag/source/languagetag/languagetag.cxx

@@ -1312,4 +1312,49 @@ LanguageTag::Extraction LanguageTag::simpleExtract( const OUString& rBcp47,
 }
 
 
+// static
+::std::vector< com::sun::star::lang::Locale >::const_iterator LanguageTag::getMatchingFallback(
+        const ::std::vector< com::sun::star::lang::Locale > & rList,
+        const com::sun::star::lang::Locale & rReference )
+{
+    if (rList.empty())
+        return rList.end();
+
+    ::std::vector< lang::Locale >::const_iterator it;
+
+    // Try the simple case first without constructing fallbacks.
+    for (it = rList.begin(); it != rList.end(); ++it)
+    {
+        if (    (*it).Language == rReference.Language &&
+                (*it).Country  == rReference.Country  &&
+                (*it).Variant  == rReference.Variant)
+            return it;  // exact match
+    }
+
+    // Now for each reference fallback test the fallbacks of the list in order.
+    ::std::vector< OUString > aFallbacks( LanguageTag( rReference).getFallbackStrings());
+    aFallbacks.erase( aFallbacks.begin());  // first is full BCP47, we already checked that
+    ::std::vector< ::std::vector< OUString > > aListFallbacks( rList.size());
+    for (it = rList.begin(); it != rList.end(); ++it)
+    {
+        ::std::vector< OUString > aTmp( LanguageTag( *it).getFallbackStrings());
+        aListFallbacks.push_back( aTmp);
+    }
+    for (::std::vector< OUString >::const_iterator rfb( aFallbacks.begin()); rfb != aFallbacks.end(); ++rfb)
+    {
+        for (::std::vector< ::std::vector< OUString > >::const_iterator lfb( aListFallbacks.begin());
+                lfb != aListFallbacks.end(); ++lfb)
+        {
+            for (::std::vector< OUString >::const_iterator fb( (*lfb).begin()); fb != (*lfb).end(); ++fb)
+            {
+                if (*rfb == *fb)
+                    return rList.begin() + (lfb - aListFallbacks.begin());
+            }
+        }
+    }
+
+    // No match found.
+    return rList.end();
+}
+
 /* vim:set shiftwidth=4 softtabstop=4 expandtab: */

include/i18nlangtag/languagetag.hxx

@@ -273,7 +273,7 @@ public:
     ::std::vector< OUString >       getFallbackStrings() const;
 
 
-    /** @short  search for an equal or at least for a similar locale in a list
+    /** @short  Search for an equal or at least for a similar locale in a list
                 of possible ones.
 
         @descr  First search for a locale that is equal to the reference
@@ -306,12 +306,39 @@ public:
 
         @return An iterator that points to the found element inside the given
                 locale list. If no matching locale could be found it points to
-                the end of the list.
+                the beginning of the list.
      */
     static ::std::vector< OUString >::const_iterator getFallback( const ::std::vector< OUString > & rList,
                                                                   const OUString & rReference );
 
 
+    /** @short  Search for an equal or for a similar locale in a list
+                of possible ones where at least the language matches.
+
+        @descr  First search for a locale that is equal to the reference
+                locale.
+
+                If the reference locale could not be located, check for
+                "similar" locales, in the same order as obtained by
+                getFallbackStrings().
+
+                If no locale matches, rList.end() is returned.
+
+        @param  rList
+                the vector of possible locales.
+
+        @param  rReference
+                the reference locale.
+
+        @return An iterator that points to the found element inside the given
+                locale list. If no matching locale could be found it points to
+                the end of the list.
+     */
+    static ::std::vector< com::sun::star::lang::Locale >::const_iterator getMatchingFallback(
+            const ::std::vector< com::sun::star::lang::Locale > & rList,
+            const com::sun::star::lang::Locale & rReference );
+
+
     /** Test equality of two LanguageTag, possibly resolving system locale.
 
         @param bResolveSystem