libreoffice/sc/source/core/tool/stringutil.cxx

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#include "stringutil.hxx"
#include "rtl/ustrbuf.hxx"
#include "rtl/math.hxx"

using ::rtl::OUString;
using ::rtl::OUStringBuffer;

ScSetStringParam::ScSetStringParam() :
    mpNumFormatter(NULL),
    mbDetectNumberFormat(true),
    mbSetTextCellFormat(false),
    mbHandleApostrophe(true)
{
}

// ============================================================================-

bool ScStringUtil::parseSimpleNumber(
    const OUString& rStr, sal_Unicode dsep, sal_Unicode gsep, double& rVal)
{
    // Actually almost the entire pre-check is unnecessary and we could call
    // rtl::math::stringToDouble() just after having exchanged ascii space with
    // non-breaking space, if it wasn't for check of grouped digits. The NaN
    // and Inf cases that are accepted by stringToDouble() could be detected
    // using rtl::math::isFinite() on the result.

    /* TODO: The grouped digits check isn't even valid for locales that do not
     * group in thousands ... e.g. Indian locales. But that's something also
     * the number scanner doesn't implement yet, only the formatter. */

    OUStringBuffer aBuf;

    sal_Int32 i = 0;
    sal_Int32 n = rStr.getLength();
    const sal_Unicode* p = rStr.getStr();
    const sal_Unicode* pLast = p + (n-1);
    sal_Int32 nPosDSep = -1, nPosGSep = -1;
    sal_uInt32 nDigitCount = 0;
    sal_Int32 nPosExponent = -1;

    // Skip preceding spaces.
    for (i = 0; i < n; ++i, ++p)
    {
        sal_Unicode c = *p;
        if (c != 0x0020 && c != 0x00A0)
            // first non-space character.  Exit.
            break;
    }

    if (i == n)
        // the whole string is space.  Fail.
        return false;

    n -= i; // Subtract the length of the preceding spaces.

    // Determine the last non-space character.
    for (; p != pLast; --pLast, --n)
    {
        sal_Unicode c = *pLast;
        if (c != 0x0020 && c != 0x00A0)
            // Non space character. Exit.
            break;
    }

    for (i = 0; i < n; ++i, ++p)
    {
        sal_Unicode c = *p;
        if (c == 0x0020 && gsep == 0x00A0)
            // ascii space to unicode space if that is group separator
            c = 0x00A0;

        if (sal_Unicode('0') <= c && c <= sal_Unicode('9'))
        {
            // this is a digit.
            aBuf.append(c);
            ++nDigitCount;
        }
        else if (c == dsep)
        {
            // this is a decimal separator.

            if (nPosDSep >= 0)
                // a second decimal separator -> not a valid number.
                return false;

            if (nPosGSep >= 0 && i - nPosGSep != 4)
                // the number has a group separator and the decimal sep is not
                // positioned correctly.
                return false;

            nPosDSep = i;
            nPosGSep = -1;
            aBuf.append(c);
            nDigitCount = 0;
        }
        else if (c == gsep)
        {
            // this is a group (thousand) separator.

            if (i == 0)
                // not allowed as the first character.
                return false;

            if (nPosDSep >= 0)
                // not allowed after the decimal separator.
                return false;

            if (nPosGSep >= 0 && nDigitCount != 3)
                // must be exactly 3 digits since the last group separator.
                return false;

            if (nPosExponent >= 0)
                // not allowed in exponent.
                return false;

            nPosGSep = i;
            nDigitCount = 0;
        }
        else if (c == sal_Unicode('-') || c == sal_Unicode('+'))
        {
            // A sign must be the first character if it's given, or immediately
            // follow the exponent character if present.
            if (i == 0 || (nPosExponent >= 0 && i == nPosExponent + 1))
                aBuf.append(c);
            else
                return false;
        }
        else if (c == sal_Unicode('E') || c == sal_Unicode('e'))
        {
            // this is an exponent designator.

            if (nPosExponent >= 0)
                // Only one exponent allowed.
                return false;

            if (nPosGSep >= 0 && nDigitCount != 3)
                // must be exactly 3 digits since the last group separator.
                return false;

            aBuf.append(c);
            nPosExponent = i;
            nPosDSep = -1;
            nPosGSep = -1;
            nDigitCount = 0;
        }
        else
            return false;
    }

    // finished parsing the number.

    if (nPosGSep >= 0 && nDigitCount != 3)
        // must be exactly 3 digits since the last group separator.
        return false;

    rtl_math_ConversionStatus eStatus = rtl_math_ConversionStatus_Ok;
    sal_Int32 nParseEnd = 0;
    OUString aString( aBuf.makeStringAndClear());
    rVal = ::rtl::math::stringToDouble( aString, dsep, gsep, &eStatus, &nParseEnd);
    if (eStatus != rtl_math_ConversionStatus_Ok || nParseEnd < aString.getLength())
        // Not a valid number or not entire string consumed.
        return false;

    return true;
}

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