diff options
Diffstat (limited to 'src/corelib')
| -rw-r--r-- | src/corelib/tools/qdatetimeparser.cpp | 189 |
1 files changed, 188 insertions, 1 deletions
diff --git a/src/corelib/tools/qdatetimeparser.cpp b/src/corelib/tools/qdatetimeparser.cpp index 632ff4c8e7..d46d9942d3 100644 --- a/src/corelib/tools/qdatetimeparser.cpp +++ b/src/corelib/tools/qdatetimeparser.cpp @@ -877,6 +877,188 @@ int QDateTimeParser::parseSection(const QDateTime ¤tValue, int sectionInde #ifndef QT_NO_DATESTRING /*! \internal + + Returns a date consistent with the given data on parts specified by known, + while staying as close to the given data as it can. Returns an invalid date + when on valid date is consistent with the data. +*/ + +static QDate actualDate(QDateTimeParser::Sections known, int year, int year2digits, + int month, int day, int dayofweek) +{ + QDate actual(year, month, day); + if (actual.isValid() && year % 100 == year2digits && actual.dayOfWeek() == dayofweek) + return actual; // The obvious candidate is fine :-) + + if (dayofweek < 1 || dayofweek > 7) // Invalid: ignore + known &= ~QDateTimeParser::DayOfWeekSectionMask; + + // Assuming year > 0 ... + if (year % 100 != year2digits) { + if (known & QDateTimeParser::YearSection2Digits) { + // Over-ride year, even if specified: + year += year2digits - year % 100; + known &= ~QDateTimeParser::YearSection; + } else { + year2digits = year % 100; + } + } + Q_ASSERT(year % 100 == year2digits); + + if (month < 1) { // If invalid, clip to nearest valid and ignore in known. + month = 1; + known &= ~QDateTimeParser::MonthSection; + } else if (month > 12) { + month = 12; + known &= ~QDateTimeParser::MonthSection; + } + + QDate first(year, month, 1); + int last = known & QDateTimeParser::YearSection && known & QDateTimeParser::MonthSection + ? first.daysInMonth() : 0; + // If we also know day-of-week, tweak last to the last in the month that matches it: + if (last && known & QDateTimeParser::DayOfWeekSectionMask) { + int diff = (dayofweek - first.dayOfWeek() - last) % 7; + Q_ASSERT(diff <= 0); // C++11 specifies (-ve) % (+ve) to be <= 0. + last += diff; + } + if (day < 1) { + if (known & QDateTimeParser::DayOfWeekSectionMask && last) { + day = 1 + dayofweek - first.dayOfWeek(); + if (day < 1) + day += 7; + } else { + day = 1; + } + known &= ~QDateTimeParser::DaySection; + } else if (day > 31) { + day = last; + known &= ~QDateTimeParser::DaySection; + } else if (last && day > last && (known & QDateTimeParser::DaySection) == 0) { + day = last; + } + + actual = QDate(year, month, day); + if (!actual.isValid() // We can't do better than we have, in this case + || (known & QDateTimeParser::DaySection + && known & QDateTimeParser::MonthSection + && known & QDateTimeParser::YearSection) // ditto + || actual.dayOfWeek() == dayofweek // Good enough, use it. + || (known & QDateTimeParser::DayOfWeekSectionMask) == 0) { // No contradiction, use it. + return actual; + } + + /* + Now it gets trickier. + + We have some inconsistency in our data; we've been told day of week, but + it doesn't fit with our year, month and day. At least one of these is + unknown, though: so we can fix day of week by tweaking it. + */ + + if ((known & QDateTimeParser::DaySection) == 0) { + // Relatively easy to fix. + day += dayofweek - actual.dayOfWeek(); + if (day < 1) + day += 7; + else if (day > actual.daysInMonth()) + day -= 7; + actual = QDate(year, month, day); + return actual; + } + + if ((known & QDateTimeParser::MonthSection) == 0) { + /* + Try possible month-offsets, m, preferring small; at least one (present + month doesn't work) and at most 11 (max month, 12, minus min, 1); try + in both directions, ignoring any offset that takes us out of range. + */ + for (int m = 1; m < 12; m++) { + if (m < month) { + actual = QDate(year, month - m, day); + if (actual.dayOfWeek() == dayofweek) + return actual; + } + if (m + month <= 12) { + actual = QDate(year, month + m, day); + if (actual.dayOfWeek() == dayofweek) + return actual; + } + } + // Should only get here in corner cases; e.g. day == 31 + actual = QDate(year, month, day); // Restore from trial values. + } + + if ((known & QDateTimeParser::YearSection) == 0) { + if (known & QDateTimeParser::YearSection2Digits) { + /* + Two-digit year and month are specified; choice of century can only + fix this if diff is in one of {1, 2, 5} or {2, 4, 6}; but not if + diff is in the other. It's also only reasonable to consider + adjacent century, e.g. if year thinks it's 2012 and two-digit year + is '97, it makes sense to consider 1997. If either adjacent + century does work, the other won't. + */ + actual = QDate(year + 100, month, day); + if (actual.dayOfWeek() == dayofweek) + return actual; + actual = QDate(year - 100, month, day); + if (actual.dayOfWeek() == dayofweek) + return actual; + } else { + // Offset by 7 is usually enough, but rare cases may need more: + for (int y = 1; y < 12; y++) { + actual = QDate(year - y, month, day); + if (actual.dayOfWeek() == dayofweek) + return actual; + actual = QDate(year + y, month, day); + if (actual.dayOfWeek() == dayofweek) + return actual; + } + } + actual = QDate(year, month, day); // Restore from trial values. + } + + return actual; // It'll just have to do :-( +} + +/*! + \internal +*/ + +static QTime actualTime(QDateTimeParser::Sections known, + int hour, int hour12, int ampm, + int minute, int second, int msec) +{ + // If we have no conflict, or don't know enough to diagonose one, use this: + QTime actual(hour, minute, second, msec); + if (hour12 < 0 || hour12 > 12) { // ignore bogus value + known &= ~QDateTimeParser::Hour12Section; + hour12 = hour % 12; + } + + if (ampm == -1 || (known & QDateTimeParser::AmPmSection) == 0) { + if ((known & QDateTimeParser::Hour12Section) == 0 || hour % 12 == hour12) + return actual; + + if ((known & QDateTimeParser::Hour24Section) == 0) + hour = hour12 + (hour > 12 ? 12 : 0); + } else { + Q_ASSERT(ampm == 0 || ampm == 1); + if (hour - hour12 == ampm * 12) + return actual; + + if ((known & QDateTimeParser::Hour24Section) == 0 + && known & QDateTimeParser::Hour12Section) { + hour = hour12 + ampm * 12; + } + } + actual = QTime(hour, minute, second, msec); + return actual; +} + +/*! + \internal */ QDateTimeParser::StateNode QDateTimeParser::parse(QString &input, int &cursorPosition, @@ -925,7 +1107,12 @@ QDateTimeParser::StateNode QDateTimeParser::parse(QString &input, int &cursorPos const SectionNode sn = sectionNodes.at(index); int used; - num = parseSection(defaultValue, index, input, cursorPosition, pos, tmpstate, &used); + num = parseSection(QDateTime(actualDate(isSet, year, year2digits, + month, day, dayofweek), + actualTime(isSet, hour, hour12, ampm, + minute, second, msec), + spec), + index, input, cursorPosition, pos, tmpstate, &used); QDTPDEBUG << "sectionValue" << sn.name() << input << "pos" << pos << "used" << used << stateName(tmpstate); if (fixup && tmpstate == Intermediate && used < sn.count) { |