introduce SvNumberFormatter::GetFormatStringForExcel()

Taking implementation from sc/source/filter/excel/xestyle.cxx
GetNumberFormatCode(), slightly modified to ensure valid conversion and
force en-US locale data. Also don't unnecessarily convert if format is
for system locale and system locale is en-US.

Change-Id: I9223eaa655132b4106a35c94cb0005559d7575b1

include/svl/zforlist.hxx

@@ -759,9 +759,19 @@ public:
     void    FillKeywordTable( NfKeywordTable& rKeywords, LanguageType eLang );
 
     /** Fill a NfKeywordIndex table with keywords usable in Excel export with
-        GetMappedFormatstring() */
+        GetFormatStringForExcel() or SvNumberformat::GetMappedFormatstring() */
     void    FillKeywordTableForExcel( NfKeywordTable& rKeywords );
 
+    /** Return a format code string suitable for Excel export.
+
+        @param  rTempFormatter
+                SvNumberFormatter to use if a non-en-US format code needs to be
+                converted and put, should not be the same formatter to not
+                pollute the entries of this one here.
+     */
+    OUString GetFormatStringForExcel( sal_uInt32 nKey, const NfKeywordTable& rKeywords,
+            SvNumberFormatter& rTempFormatter ) const;
+
     /** Return a keyword for a language/country and NfKeywordIndex
         for XML import, to generate number format strings. */
     OUString GetKeyword( LanguageType eLnge, sal_uInt16 nIndex );

svl/source/numbers/zforlist.cxx

@@ -791,6 +791,62 @@ void SvNumberFormatter::FillKeywordTableForExcel( NfKeywordTable& rKeywords )
 }
 
 
+OUString SvNumberFormatter::GetFormatStringForExcel( sal_uInt32 nKey, const NfKeywordTable& rKeywords,
+        SvNumberFormatter& rTempFormatter ) const
+{
+    OUString aFormatStr;
+    if (const SvNumberformat* pEntry = GetEntry( nKey))
+    {
+        if (pEntry->GetType() == css::util::NumberFormat::LOGICAL)
+        {
+            // Build Boolean number format, which needs non-zero and zero
+            // subformat codes with TRUE and FALSE strings.
+            Color* pColor = nullptr;
+            OUString aTemp;
+            const_cast< SvNumberformat* >( pEntry )->GetOutputString( 1.0, aTemp, &pColor );
+            aFormatStr += "\"" + aTemp + "\";\"" + aTemp + "\";\"";
+            const_cast< SvNumberformat* >( pEntry )->GetOutputString( 0.0, aTemp, &pColor );
+            aFormatStr += aTemp + "\"";
+        }
+        else
+        {
+            LanguageType nLang = pEntry->GetLanguage();
+            if (nLang == LANGUAGE_SYSTEM)
+                nLang = SvtSysLocale().GetLanguageTag().getLanguageType();
+            if (nLang != LANGUAGE_ENGLISH_US)
+            {
+                sal_Int32 nCheckPos;
+                short nType = css::util::NumberFormat::DEFINED;
+                sal_uInt32 nTempKey;
+                OUString aTemp( pEntry->GetFormatstring());
+                rTempFormatter.PutandConvertEntry( aTemp, nCheckPos, nType, nTempKey, nLang, LANGUAGE_ENGLISH_US);
+                SAL_WARN_IF( nCheckPos != 0, "svl.numbers",
+                        "SvNumberFormatter::GetFormatStringForExcel - format code not convertible");
+                if (nTempKey != NUMBERFORMAT_ENTRY_NOT_FOUND)
+                    pEntry = rTempFormatter.GetEntry( nTempKey);
+            }
+
+            if (pEntry)
+            {
+                // GetLocaleData() returns the current locale's data, so switch
+                // before (which doesn't do anything if it was the same locale
+                // already).
+                rTempFormatter.ChangeIntl( LANGUAGE_ENGLISH_US);
+                aFormatStr = pEntry->GetMappedFormatstring( rKeywords, *rTempFormatter.GetLocaleData());
+            }
+        }
+    }
+    else
+    {
+        SAL_WARN("svl.numbers","SvNumberFormatter::GetFormatStringForExcel - format not found: " << nKey);
+    }
+
+    if (aFormatStr.isEmpty())
+        aFormatStr = "General";
+    return aFormatStr;
+}
+
+
 OUString SvNumberFormatter::GetKeyword( LanguageType eLnge, sal_uInt16 nIndex )
 {
     ChangeIntl(eLnge);