introduce LocaleDataWrapper::doesSecondaryCalendarUseEC()

Preparing to replace the number format import hack of
95c91f09 and generalizing for known locales.

Change-Id: I0413987e302eaa84ef6a7dde2ecb365144313e81

include/unotools/localedatawrapper.hxx

@@ -58,6 +58,7 @@ class UNOTOOLS_DLLPUBLIC LocaleDataWrapper
     css::uno::Reference< css::i18n::XLocaleData4 >     xLD;
     LanguageTag                                        maLanguageTag;
     std::shared_ptr< css::i18n::Calendar2 >            xDefaultCalendar;
+    std::shared_ptr< css::i18n::Calendar2 >            xSecondaryCalendar;
     css::i18n::LocaleDataItem                          aLocaleDataItem;
     css::uno::Sequence< OUString >                     aReservedWordSeq;
     css::uno::Sequence< OUString >                     aDateAcceptancePatterns;
@@ -74,6 +75,7 @@ class UNOTOOLS_DLLPUBLIC LocaleDataWrapper
     sal_uInt16              nCurrDigits;
     bool                    bLocaleDataItemValid;
     bool                    bReservedWordValid;
+    bool                    bSecondaryCalendarValid;
     mutable ::utl::ReadWriteMutex   aMutex;
     struct Locale_Compare
     {
@@ -105,6 +107,7 @@ class UNOTOOLS_DLLPUBLIC LocaleDataWrapper
     DateFormat          scanDateFormatImpl( const OUString& rCode );
 
     void                getDefaultCalendarImpl();
+    void                getSecondaryCalendarImpl();
 
     sal_Unicode*        ImplAddFormatNum( sal_Unicode* pBuf,
                             sal_Int64 nNumber, sal_uInt16 nDecimals,
@@ -183,6 +186,10 @@ public:
     /// Convenience method to obtain the month names of the default calendar.
     const css::uno::Sequence< css::i18n::CalendarItem2 > getDefaultCalendarMonths() const;
 
+    /** If the secondary calendar, if any, is of the name passed AND number
+        formats using it usually use the E or EE keyword (EC|EEC). */
+    bool doesSecondaryCalendarUseEC( const OUString& rName ) const;
+
     /** Obtain digit grouping. The usually known grouping by thousands (#,###)
         is actually only one of possible groupings. Another one, for example,
         used in India is group by 3 and then by 2 indefinitely (#,##,###). The

unotools/source/i18n/localedatawrapper.cxx

@@ -89,7 +89,8 @@ LocaleDataWrapper::LocaleDataWrapper(
         xLD( LocaleData::create(rxContext) ),
         maLanguageTag( rLanguageTag ),
         bLocaleDataItemValid( false ),
-        bReservedWordValid( false )
+        bReservedWordValid( false ),
+        bSecondaryCalendarValid( false )
 {
     invalidateData();
 }
@@ -102,7 +103,8 @@ LocaleDataWrapper::LocaleDataWrapper(
         xLD( LocaleData::create(m_xContext) ),
         maLanguageTag( rLanguageTag ),
         bLocaleDataItemValid( false ),
-        bReservedWordValid( false )
+        bReservedWordValid( false ),
+        bSecondaryCalendarValid( false )
 {
     invalidateData();
 }
@@ -149,6 +151,8 @@ void LocaleDataWrapper::invalidateData()
         bReservedWordValid = false;
     }
     xDefaultCalendar.reset();
+    xSecondaryCalendar.reset();
+    bSecondaryCalendarValid = false;
     if (aGrouping.getLength())
         aGrouping[0] = 0;
     if (aDateAcceptancePatterns.getLength())
@@ -475,6 +479,59 @@ MeasurementSystem LocaleDataWrapper::mapMeasurementStringToEnum( const OUString&
     return MEASURE_US;
 }
 
+void LocaleDataWrapper::getSecondaryCalendarImpl()
+{
+    if (!xSecondaryCalendar && !bSecondaryCalendarValid)
+    {
+        Sequence< Calendar2 > xCals = getAllCalendars();
+        sal_Int32 nCount = xCals.getLength();
+        if (nCount > 1)
+        {
+            sal_Int32 nNonDef = -1;
+            const Calendar2* pArr = xCals.getArray();
+            for (sal_Int32 i=0; i<nCount; ++i)
+            {
+                if (!pArr[i].Default)
+                {
+                    nNonDef = i;
+                    break;
+                }
+            }
+            if (nNonDef >= 0)
+                xSecondaryCalendar.reset( new Calendar2( xCals[nNonDef]));
+        }
+        bSecondaryCalendarValid = true;
+    }
+}
+
+bool LocaleDataWrapper::doesSecondaryCalendarUseEC( const OUString& rName ) const
+{
+    if (rName.isEmpty())
+        return false;
+
+    ::utl::ReadWriteGuard aGuard( aMutex );
+
+    if (!bSecondaryCalendarValid)
+    {   // no cached content
+        aGuard.changeReadToWrite();
+        const_cast<LocaleDataWrapper*>(this)->getSecondaryCalendarImpl();
+    }
+    if (!xSecondaryCalendar)
+        return false;
+    if (!xSecondaryCalendar->Name.equalsIgnoreAsciiCase( rName))
+        return false;
+
+    LanguageTag aLoaded( getLoadedLanguageTag());
+    OUString aBcp47( aLoaded.getBcp47());
+    // So far determine only by locale, we know for a few.
+    /* TODO: check date format codes? or add to locale data? */
+    return
+        aBcp47 == "ja-JP" ||
+        aBcp47 == "lo-LA" ||
+        aBcp47 == "zh-TW"
+        ;
+}
+
 void LocaleDataWrapper::getDefaultCalendarImpl()
 {
     if (!xDefaultCalendar)