// instead of modifying the member fields directly!
struct Tm
{
- wxDateTime_t sec, min, hour, mday;
+ wxDateTime_t msec, sec, min, hour, mday;
Month mon;
int year;
}
// add the given number of months to the date keeping it normalized
- void AddMonths(wxDateTime_t monDiff);
+ void AddMonths(int monDiff);
// add the given number of months to the date keeping it normalized
- void AddDays(wxDateTime_t dayDiff);
+ void AddDays(int dayDiff);
private:
// compute the weekday from other fields
// from broken down time/date (any range)
inline wxDateTime(const Tm& tm);
+ // from JDN (beware of rounding errors)
+ inline wxDateTime(double jdn);
+
// from separate values for each component, date set to today
inline wxDateTime(wxDateTime_t hour,
wxDateTime_t minute = 0,
// set to given broken down time/date
inline wxDateTime& Set(const Tm& tm);
+ // set to given JDN (beware of rounding errors)
+ wxDateTime& Set(double jdn);
+
// set to given time, date = today
wxDateTime& Set(wxDateTime_t hour,
wxDateTime_t minute = 0,
// of days relative to a base date of December 31 of the year 0. Thus
// January 1 of the year 1 is Rata Die day 1.
- // get the Julian Day number
- long GetJulianDay() const;
+ // get the Julian Day number (the fractional part specifies the time of
+ // the day, related to noon - beware of rounding errors!)
+ double GetJulianDayNumber() const;
// get the Rata Die number
- long GetRataDie() const;
+ double GetRataDie() const;
// TODO algorithms for calculating some important dates, such as
// religious holidays (Easter...) or moon/solar eclipses? Some
// timespans are equal in absolute value.
bool IsShorterThan(const wxTimeSpan& t) const { return !IsLongerThan(t); }
- // breaking into years, ..., days, ..., seconds: all these functions
- // behave like GetYears() which returns 1 for the timespan of 1 year and 1
- // day, but 0 (and not -1) for the negative timespan of 1 year without 1
- // day. IOW, (ts - wxTimeSpan(ts.GetYears())).GetYears() is always 0.
+ // breaking into days, hours, minutes and seconds
// ------------------------------------------------------------------------
- // get the max number of years in this timespan
- inline int GetYears() const;
- // get the max number of months in this timespan
- inline int GetMonths() const;
// get the max number of weeks in this timespan
inline int GetWeeks() const;
// get the max number of days in this timespan
// get the max number of minutes in this timespan
inline int GetMinutes() const;
// get the max number of seconds in this timespan
- inline int GetSeconds() const;
+ inline wxLongLong GetSeconds() const;
// get the number of milliseconds in this timespan
wxLongLong GetMilliseconds() const { return m_diff; }
// constants
// ----------------------------------------------------------------------------
-// note that all these constants should be signed or we'd get some big
-// surprizes with C integer arithmetics
+// some trivial ones
static const int MONTHS_IN_YEAR = 12;
static const int SECONDS_IN_MINUTE = 60;
-// the number of days in month in Julian/Gregorian calendar: the first line is
-// for normal years, the second one is for the leap ones
-static wxDateTime::wxDateTime_t gs_daysInMonth[2][MONTHS_IN_YEAR] =
-{
- { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
- { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
-};
+static const long SECONDS_PER_DAY = 86400l;
+
+static const long MILLISECONDS_PER_DAY = 86400000l;
+
+// this is the integral part of JDN of the midnight of Jan 1, 1970
+// (i.e. JDN(Jan 1, 1970) = 2440587.5)
+static const int EPOCH_JDN = 2440587;
// ----------------------------------------------------------------------------
// globals
static inline
wxDateTime::wxDateTime_t GetNumOfDaysInMonth(int year, wxDateTime::Month month)
{
- return gs_daysInMonth[wxDateTime::IsLeapYear(year)][month];
+ // the number of days in month in Julian/Gregorian calendar: the first line
+ // is for normal years, the second one is for the leap ones
+ static wxDateTime::wxDateTime_t daysInMonth[2][MONTHS_IN_YEAR] =
+ {
+ { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
+ { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 }
+ };
+
+ return daysInMonth[wxDateTime::IsLeapYear(year)][month];
}
// ensure that the timezone variable is set by calling localtime
if ( !s_timezoneSet )
{
- (void)localtime(0);
+ // just call localtime() instead of figurin out whether this system
+ // supports tzset(), _tzset() or something else
+ time_t t;
+ (void)localtime(&t);
s_timezoneSet = TRUE;
}
return (int)timezone;
}
+// return the integral part of the JDN for the midnight of the given date (to
+// get the real JDN you need to add 0.5, this is, in fact, JDN of the noon of
+// the previous day)
+static long GetTruncatedJDN(wxDateTime::wxDateTime_t day,
+ wxDateTime::Month mon,
+ int year)
+{
+ // CREDIT: the algorithm was taken from Peter Baum's home page
+
+ // the algorithm assumes Jan == 1
+ int month = mon + 1;
+
+ // we want the leap day (Feb 29) be at the end of the year, so we count
+ // March as the first month
+ if ( month < wxDateTime::Mar + 1 )
+ {
+ month += MONTHS_IN_YEAR;
+ year--;
+ }
+
+ // this table contains the number of the days before the 1st of the each
+ // month (in a non leap year) with the third value corresponding to March
+ // (and the last one to February)
+ static const int monthOffsets[14] =
+ {
+ 0, 31, 61, 92, 122, 153, 184, 214, 245, 275, 306
+ };
+
+ // and now add contributions of all terms together to get the result (you'd
+ // better see the Web page for the description if you want to understand
+ // why it works (if it does :-))
+ return day +
+ // linear approximation for months
+ monthOffsets[month - (wxDateTime::Mar + 1)] +
+ // the year contribution
+ 365*year + year/4 - year/100 + year/400 +
+ // 1721119.5 is the JDN of the midnight of Mar 1, year 0
+ 1721118;
+}
+
// this function is a wrapper around strftime(3)
static wxString CallStrftime(const wxChar *format, const tm* tm)
{
year = (wxDateTime_t)wxDateTime::Inv_Year;
mon = wxDateTime::Inv_Month;
mday = 0;
- hour = min = sec = 0;
+ hour = min = sec = msec = 0;
wday = wxDateTime::Inv_WeekDay;
}
wxDateTime::Tm::Tm(const struct tm& tm)
{
+ msec = 0;
sec = tm.tm_sec;
min = tm.tm_min;
hour = tm.tm_hour;
// we allow for the leap seconds, although we don't use them (yet)
return (year != wxDateTime::Inv_Year) && (mon != wxDateTime::Inv_Month) &&
(mday < GetNumOfDaysInMonth(year, mon)) &&
- (hour < 24) && (min < 60) && (sec < 62);
+ (hour < 24) && (min < 60) && (sec < 62) && (msec < 1000);
}
void wxDateTime::Tm::ComputeWeekDay()
wxFAIL_MSG(_T("TODO"));
}
-void wxDateTime::Tm::AddMonths(wxDateTime::wxDateTime_t monDiff)
+void wxDateTime::Tm::AddMonths(int monDiff)
{
// normalize the months field
while ( monDiff < -mon )
mon = (wxDateTime::Month)(mon + monDiff);
- wxASSERT_MSG( mon >= 0 && mon < 12, _T("logic error") );
+ wxASSERT_MSG( mon >= 0 && mon < MONTHS_IN_YEAR, _T("logic error") );
}
-void wxDateTime::Tm::AddDays(wxDateTime::wxDateTime_t dayDiff)
+void wxDateTime::Tm::AddDays(int dayDiff)
{
// normalize the days field
mday += dayDiff;
{
// do time calculations ourselves: we want to calculate the number of
// milliseconds between the given date and the epoch
- wxFAIL_MSG(_T("TODO"));
+
+ // get the JDN for the midnight of this day
+ m_time = GetTruncatedJDN(day, month, year);
+ m_time -= EPOCH_JDN;
+ m_time *= SECONDS_PER_DAY * TIME_T_FACTOR;
+
+ Add(wxTimeSpan(hour, minute, second, millisec));
}
return *this;
}
+wxDateTime& wxDateTime::Set(double jdn)
+{
+ m_time = (jdn - 0.5 - EPOCH_JDN) * TIME_T_FACTOR;
+
+ return *this;
+}
+
// ----------------------------------------------------------------------------
// time_t <-> broken down time conversions
// ----------------------------------------------------------------------------
}
else
{
- wxFAIL_MSG(_T("TODO"));
+ // CREDIT: the algorithm was taken from Peter Baum's home page
+
+ // calculate the Gregorian date from JDN for the midnight of our date
+ wxLongLong timeMidnight = m_time;
+ long timeOnly = (m_time % MILLISECONDS_PER_DAY).GetLo();
+ timeMidnight -= timeOnly;
+
+ // TODO this probably could be optimised somehow...
+
+ double jdn = (timeMidnight / MILLISECONDS_PER_DAY).GetLo();
+ jdn += EPOCH_JDN + 0.5;
+ long z = jdn - 1721118.5;
+ double r = jdn - 1721118.5 - z;
+ double g = z - 0.25;
+ long a = g/36524.25; // number of days per year
+ long b = a - a / 4;
+ int year = (b + g) / 365.25;
+ long c = b + z - 365.25*year;
+ int month = (5*c + 456)/153;
+ int day = c - (153*month - 457)/5 + (r < 0.5 ? 0 : 1);
+ if ( month > 12 )
+ {
+ year++;
+ month -= 12;
+ }
+
+ Tm tm;
+ tm.year = year;
+ tm.mon = (Month)(month - 1); // algorithm yields 1 for January, not 0
+ tm.mday = day;
+ tm.msec = timeOnly % 1000;
+ timeOnly -= tm.msec;
+ timeOnly /= 1000; // now we have time in seconds
+
+ tm.sec = timeOnly % 60;
+ timeOnly -= tm.sec;
+ timeOnly /= 60; // now we have time in minutes
+
+ tm.min = timeOnly % 60;
+ timeOnly -= tm.min;
+
+ tm.hour = timeOnly / 60;
- return Tm();
+ return tm;
}
}
}
}
+// ----------------------------------------------------------------------------
+// Julian day number conversion and related stuff
+// ----------------------------------------------------------------------------
+
+double wxDateTime::GetJulianDayNumber() const
+{
+ Tm tm(GetTm());
+
+ double result = GetTruncatedJDN(tm.mday, tm.mon, tm.year);
+
+ // add the part GetTruncatedJDN() neglected
+ result += 0.5;
+
+ // and now add the time: 86400 sec = 1 JDN
+ return result + ((double)(60*(60*tm.hour + tm.min) + tm.sec)) / 86400;
+}
+
+double wxDateTime::GetRataDie() const
+{
+ // March 1 of the year 0 is Rata Die day -306 and JDN 1721119.5
+ return GetJulianDayNumber() - 1721119.5 - 306;
+}
+
// ----------------------------------------------------------------------------
// timezone stuff
// ----------------------------------------------------------------------------
wxString wxDateTime::Format(const wxChar *format) const
{
+ wxCHECK_MSG( format, _T(""), _T("NULL format in wxDateTime::Format") );
+
time_t time = GetTicks();
if ( time != (time_t)-1 )
{
}
else
{
- wxFAIL_MSG(_T("TODO"));
+ // use a hack and still use strftime(): make a copy of the format and
+ // replace all occurences of YEAR in it with some unique string not
+ // appearing anywhere else in it, then use strftime() to format the
+ // date in year YEAR and then replace YEAR back by the real year and
+ // the unique replacement string back with YEAR where YEAR is any year
+ // in the range supported by strftime() (1970 - 2037) which is equal to
+ // the real year modulo 28 (so the week days coincide for them)
+
+ // find the YEAR
+ int yearReal = GetYear();
+ int year = 1970 + yearReal % 28;
+
+ wxString strYear;
+ strYear.Printf(_T("%d"), year);
+
+ // find a string not occuring in format (this is surely not optimal way
+ // of doing it... improvements welcome!)
+ wxString fmt = format;
+ wxString replacement = (wxChar)-1;
+ while ( fmt.Find(replacement) != wxNOT_FOUND )
+ {
+ replacement << (wxChar)-1;
+ }
+
+ // replace all occurences of year with it
+ bool wasReplaced = fmt.Replace(strYear, replacement) > 0;
+
+ // use strftime() to format the same date but in supported year
+ wxDateTime dt(*this);
+ dt.SetYear(year);
+ wxString str = dt.Format(format);
- return _T("");
+ // now replace the occurence of 1999 with the real year
+ wxString strYearReal;
+ strYearReal.Printf(_T("%d"), yearReal);
+ str.Replace(strYear, strYearReal);
+
+ // and replace back all occurences of replacement string
+ if ( wasReplaced )
+ str.Replace(replacement, strYear);
+
+ return str;
}
}
// wxTimeSpan
// ============================================================================
+// not all strftime(3) format specifiers make sense here because, for example,
+// a time span doesn't have a year nor a timezone
+//
+// Here are the ones which are supported (all of them are supported by strftime
+// as well):
+// %H hour in 24 hour format
+// %M minute (00 - 59)
+// %S second (00 - 59)
+// %% percent sign
+//
+// Also, for MFC CTimeSpan compatibility, we support
+// %D number of days
+//
+// And, to be better than MFC :-), we also have
+// %E number of wEeks
+// %l milliseconds (000 - 999)
wxString wxTimeSpan::Format(const wxChar *format) const
{
- wxFAIL_MSG( _T("TODO") );
+ wxCHECK_MSG( format, _T(""), _T("NULL format in wxTimeSpan::Format") );
wxString str;
+ str.Alloc(strlen(format));
+
+ for ( const wxChar *pch = format; pch; pch++ )
+ {
+ wxChar ch = *pch;
+
+ if ( ch == '%' )
+ {
+ wxString tmp;
+
+ ch = *pch++;
+ switch ( ch )
+ {
+ default:
+ wxFAIL_MSG( _T("invalid format character") );
+ // fall through
+
+ case '%':
+ // will get to str << ch below
+ break;
+
+ case 'D':
+ tmp.Printf(_T("%d"), GetDays());
+ break;
+
+ case 'E':
+ tmp.Printf(_T("%d"), GetWeeks());
+ break;
+
+ case 'H':
+ tmp.Printf(_T("%02d"), GetHours());
+ break;
+
+ case 'l':
+ tmp.Printf(_T("%03d"), GetMilliseconds());
+ break;
+
+ case 'M':
+ tmp.Printf(_T("%02d"), GetMinutes());
+ break;
+
+ case 'S':
+ tmp.Printf(_T("%02d"), GetSeconds());
+ break;
+ }
+
+ if ( !!tmp )
+ {
+ str += tmp;
+
+ // skip str += ch below
+ continue;
+ }
+ }
+
+ str += ch;
+ }
return str;
}
projects / wxWidgets.git / commitdiff
