Cue the smarter version of GetDateFormat... ok, it's a wrap!

I've mentioned Tarek Mahmoud Sayed from the GIFT development team in the past. The other day, in helping out some folks who were dealing with the issues I pointed out in How To [NOT] detect that a locale is bidi and They make 'em smarter than GetDateFormat, and at the end of the conversation had produced a nice wrapper around GetDateFormat that takes away the bulk of the need for developers calling GetDateFormat to figure out what flags to pass if they are not sure.

I thought maybe I would post the code here so others could benefit! :-)

Anyway, here is the wrapper:

int GetDateFormatWrapper(
    LCID Locale,
    DWORD dwFlags,
    CONST SYSTEMTIME* lpDate,
    LPCTSTR lpFormat,
    LPTSTR lpDateStr,
    int cchDate
)
{
    DWORD dwBidiFlags = 0;

    if ((dwFlags & (DATE_LTRREADING | DATE_RTLREADING)) == 0)
    {
        WCHAR FontSignature[16];
        CALID CalId;

        dwBidiFlags = DATE_LTRREADING;

        if (GetLocaleInfo(
                Locale,
                LOCALE_FONTSIGNATURE,
                (LPWSTR) FontSignature,
                sizeof(FontSignature)/sizeof(FontSignature[0]))
             &&
                FontSignature[7] & 0x0800
             &&
                GetLocaleInfo(Locale,
                    LOCALE_ICALENDARTYPE | LOCALE_RETURN_NUMBER,
                    (LPWSTR) &CalId,
                    sizeof(CalId)/sizeof(WCHAR))) {

            // Bidi Locale
            if (PRIMARYLANGID(LANGIDFROMLCID(Locale)) == LANG_HEBREW) {
                if ((dwFlags & DATE_SHORTDATE) == 0 || CalId == CAL_HEBREW) {
                    dwBidiFlags = DATE_RTLREADING;
                }
            } else if ( CalId == CAL_GREGORIAN ||
                        CalId == CAL_HIJRI ||
                        CalId == 23 || // CAL_UMALQURA
                        CalId == CAL_GREGORIAN_ARABIC ||
                        CalId == CAL_GREGORIAN_XLIT_ENGLISH ||
                        CalId == CAL_GREGORIAN_XLIT_FRENCH) {
                dwBidiFlags = DATE_RTLREADING;
            }
        }
    }

    return GetDateFormat(Locale, dwFlags | dwBidiFlags, lpDate, lpFormat, lpDateStr, cchDate);
}

This function has some very compelling features to it, such as the fact that it integrates the IsBidi sort of code I talked about previously and that the signature of the wrapper is identical, but what I like best about it is that if this functionality were added to GetDateFormat in a future version of Windows that then none of the code calling the wrapper would be broken. :-)

Enjoy!

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