X-Git-Url: http://review.tizen.org/git/?a=blobdiff_plain;f=glib%2Fgdate.c;h=670f7aa5fed6a3e68721891eed5b6ac752de98d1;hb=30ed5f53e205e6bfc35126a9d3c62dac8a9c5dad;hp=9b6fb4cf915e2b87d1dc15d8ff4a48da2a1eafc5;hpb=bdc23c44e8fbb507e14056a05e38b92982df7a5f;p=platform%2Fupstream%2Fglib.git
diff --git a/glib/gdate.c b/glib/gdate.c
index 9b6fb4c..670f7aa 100644
--- a/glib/gdate.c
+++ b/glib/gdate.c
@@ -12,9 +12,7 @@
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
- * License along with this library; if not, write to the
- * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
- * Boston, MA 02111-1307, USA.
+ * License along with this library; if not, see .
*/
/*
@@ -58,6 +56,208 @@
#include "garray.h"
#endif
+/**
+ * SECTION:date
+ * @title: Date and Time Functions
+ * @short_description: calendrical calculations and miscellaneous time stuff
+ *
+ * The #GDate data structure represents a day between January 1, Year 1,
+ * and sometime a few thousand years in the future (right now it will go
+ * to the year 65535 or so, but g_date_set_parse() only parses up to the
+ * year 8000 or so - just count on "a few thousand"). #GDate is meant to
+ * represent everyday dates, not astronomical dates or historical dates
+ * or ISO timestamps or the like. It extrapolates the current Gregorian
+ * calendar forward and backward in time; there is no attempt to change
+ * the calendar to match time periods or locations. #GDate does not store
+ * time information; it represents a day.
+ *
+ * The #GDate implementation has several nice features; it is only a
+ * 64-bit struct, so storing large numbers of dates is very efficient. It
+ * can keep both a Julian and day-month-year representation of the date,
+ * since some calculations are much easier with one representation or the
+ * other. A Julian representation is simply a count of days since some
+ * fixed day in the past; for #GDate the fixed day is January 1, 1 AD.
+ * ("Julian" dates in the #GDate API aren't really Julian dates in the
+ * technical sense; technically, Julian dates count from the start of the
+ * Julian period, Jan 1, 4713 BC).
+ *
+ * #GDate is simple to use. First you need a "blank" date; you can get a
+ * dynamically allocated date from g_date_new(), or you can declare an
+ * automatic variable or array and initialize it to a sane state by
+ * calling g_date_clear(). A cleared date is sane; it's safe to call
+ * g_date_set_dmy() and the other mutator functions to initialize the
+ * value of a cleared date. However, a cleared date is initially
+ * invalid, meaning that it doesn't represent a day that exists.
+ * It is undefined to call any of the date calculation routines on an
+ * invalid date. If you obtain a date from a user or other
+ * unpredictable source, you should check its validity with the
+ * g_date_valid() predicate. g_date_valid() is also used to check for
+ * errors with g_date_set_parse() and other functions that can
+ * fail. Dates can be invalidated by calling g_date_clear() again.
+ *
+ * It is very important to use the API to access the #GDate
+ * struct. Often only the day-month-year or only the Julian
+ * representation is valid. Sometimes neither is valid. Use the API.
+ *
+ * GLib also features #GDateTime which represents a precise time.
+ */
+
+/**
+ * G_USEC_PER_SEC:
+ *
+ * Number of microseconds in one second (1 million).
+ * This macro is provided for code readability.
+ */
+
+/**
+ * GTimeVal:
+ * @tv_sec: seconds
+ * @tv_usec: microseconds
+ *
+ * Represents a precise time, with seconds and microseconds.
+ * Similar to the struct timeval returned by the gettimeofday()
+ * UNIX system call.
+ *
+ * GLib is attempting to unify around the use of 64bit integers to
+ * represent microsecond-precision time. As such, this type will be
+ * removed from a future version of GLib.
+ */
+
+/**
+ * GDate:
+ * @julian_days: the Julian representation of the date
+ * @julian: this bit is set if @julian_days is valid
+ * @dmy: this is set if @day, @month and @year are valid
+ * @day: the day of the day-month-year representation of the date,
+ * as a number between 1 and 31
+ * @month: the day of the day-month-year representation of the date,
+ * as a number between 1 and 12
+ * @year: the day of the day-month-year representation of the date
+ *
+ * Represents a day between January 1, Year 1 and a few thousand years in
+ * the future. None of its members should be accessed directly.
+ *
+ * If the #GDate-struct is obtained from g_date_new(), it will be safe
+ * to mutate but invalid and thus not safe for calendrical computations.
+ *
+ * If it's declared on the stack, it will contain garbage so must be
+ * initialized with g_date_clear(). g_date_clear() makes the date invalid
+ * but sane. An invalid date doesn't represent a day, it's "empty." A date
+ * becomes valid after you set it to a Julian day or you set a day, month,
+ * and year.
+ */
+
+/**
+ * GTime:
+ *
+ * Simply a replacement for time_t. It has been deprecated
+ * since it is not equivalent to time_t on 64-bit platforms
+ * with a 64-bit time_t. Unrelated to #GTimer.
+ *
+ * Note that #GTime is defined to always be a 32-bit integer,
+ * unlike time_t which may be 64-bit on some systems. Therefore,
+ * #GTime will overflow in the year 2038, and you cannot use the
+ * address of a #GTime variable as argument to the UNIX time()
+ * function.
+ *
+ * Instead, do the following:
+ * |[
+ * time_t ttime;
+ * GTime gtime;
+ *
+ * time (&ttime);
+ * gtime = (GTime)ttime;
+ * ]|
+ */
+
+/**
+ * GDateDMY:
+ * @G_DATE_DAY: a day
+ * @G_DATE_MONTH: a month
+ * @G_DATE_YEAR: a year
+ *
+ * This enumeration isn't used in the API, but may be useful if you need
+ * to mark a number as a day, month, or year.
+ */
+
+/**
+ * GDateDay:
+ *
+ * Integer representing a day of the month; between 1 and 31.
+ * #G_DATE_BAD_DAY represents an invalid day of the month.
+ */
+
+/**
+ * GDateMonth:
+ * @G_DATE_BAD_MONTH: invalid value
+ * @G_DATE_JANUARY: January
+ * @G_DATE_FEBRUARY: February
+ * @G_DATE_MARCH: March
+ * @G_DATE_APRIL: April
+ * @G_DATE_MAY: May
+ * @G_DATE_JUNE: June
+ * @G_DATE_JULY: July
+ * @G_DATE_AUGUST: August
+ * @G_DATE_SEPTEMBER: September
+ * @G_DATE_OCTOBER: October
+ * @G_DATE_NOVEMBER: November
+ * @G_DATE_DECEMBER: December
+ *
+ * Enumeration representing a month; values are #G_DATE_JANUARY,
+ * #G_DATE_FEBRUARY, etc. #G_DATE_BAD_MONTH is the invalid value.
+ */
+
+/**
+ * GDateYear:
+ *
+ * Integer representing a year; #G_DATE_BAD_YEAR is the invalid
+ * value. The year must be 1 or higher; negative (BC) years are not
+ * allowed. The year is represented with four digits.
+ */
+
+/**
+ * GDateWeekday:
+ * @G_DATE_BAD_WEEKDAY: invalid value
+ * @G_DATE_MONDAY: Monday
+ * @G_DATE_TUESDAY: Tuesday
+ * @G_DATE_WEDNESDAY: Wednesday
+ * @G_DATE_THURSDAY: Thursday
+ * @G_DATE_FRIDAY: Friday
+ * @G_DATE_SATURDAY: Saturday
+ * @G_DATE_SUNDAY: Sunday
+ *
+ * Enumeration representing a day of the week; #G_DATE_MONDAY,
+ * #G_DATE_TUESDAY, etc. #G_DATE_BAD_WEEKDAY is an invalid weekday.
+ */
+
+/**
+ * G_DATE_BAD_DAY:
+ *
+ * Represents an invalid #GDateDay.
+ */
+
+/**
+ * G_DATE_BAD_JULIAN:
+ *
+ * Represents an invalid Julian day number.
+ */
+
+/**
+ * G_DATE_BAD_YEAR:
+ *
+ * Represents an invalid year.
+ */
+
+/**
+ * g_date_new:
+ *
+ * Allocates a #GDate and initializes
+ * it to a sane state. The new date will
+ * be cleared (as if you'd called g_date_clear()) but invalid (it won't
+ * represent an existing day). Free the return value with g_date_free().
+ *
+ * Returns: a newly-allocated #GDate
+ */
GDate*
g_date_new (void)
{
@@ -66,6 +266,18 @@ g_date_new (void)
return d;
}
+/**
+ * g_date_new_dmy:
+ * @day: day of the month
+ * @month: month of the year
+ * @year: year
+ *
+ * Like g_date_new(), but also sets the value of the date. Assuming the
+ * day-month-year triplet you pass in represents an existing day, the
+ * returned date will be valid.
+ *
+ * Returns: a newly-allocated #GDate initialized with @day, @month, and @year
+ */
GDate*
g_date_new_dmy (GDateDay day,
GDateMonth m,
@@ -88,32 +300,58 @@ g_date_new_dmy (GDateDay day,
return d;
}
+/**
+ * g_date_new_julian:
+ * @julian_day: days since January 1, Year 1
+ *
+ * Like g_date_new(), but also sets the value of the date. Assuming the
+ * Julian day number you pass in is valid (greater than 0, less than an
+ * unreasonably large number), the returned date will be valid.
+ *
+ * Returns: a newly-allocated #GDate initialized with @julian_day
+ */
GDate*
-g_date_new_julian (guint32 j)
+g_date_new_julian (guint32 julian_day)
{
GDate *d;
- g_return_val_if_fail (g_date_valid_julian (j), NULL);
+ g_return_val_if_fail (g_date_valid_julian (julian_day), NULL);
d = g_new (GDate, 1);
d->julian = TRUE;
d->dmy = FALSE;
- d->julian_days = j;
+ d->julian_days = julian_day;
g_assert (g_date_valid (d));
return d;
}
+/**
+ * g_date_free:
+ * @date: a #GDate to free
+ *
+ * Frees a #GDate returned from g_date_new().
+ */
void
-g_date_free (GDate *d)
+g_date_free (GDate *date)
{
- g_return_if_fail (d != NULL);
+ g_return_if_fail (date != NULL);
- g_free (d);
+ g_free (date);
}
+/**
+ * g_date_valid:
+ * @date: a #GDate to check
+ *
+ * Returns %TRUE if the #GDate represents an existing day. The date must not
+ * contain garbage; it should have been initialized with g_date_clear()
+ * if it wasn't allocated by one of the g_date_new() variants.
+ *
+ * Returns: Whether the date is valid
+ */
gboolean
g_date_valid (const GDate *d)
{
@@ -134,36 +372,94 @@ static const guint16 days_in_year[2][14] =
{ 0, 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 }
};
+/**
+ * g_date_valid_month:
+ * @month: month
+ *
+ * Returns %TRUE if the month value is valid. The 12 #GDateMonth
+ * enumeration values are the only valid months.
+ *
+ * Returns: %TRUE if the month is valid
+ */
gboolean
g_date_valid_month (GDateMonth m)
{
return ( (m > G_DATE_BAD_MONTH) && (m < 13) );
}
+/**
+ * g_date_valid_year:
+ * @year: year
+ *
+ * Returns %TRUE if the year is valid. Any year greater than 0 is valid,
+ * though there is a 16-bit limit to what #GDate will understand.
+ *
+ * Returns: %TRUE if the year is valid
+ */
gboolean
g_date_valid_year (GDateYear y)
{
return ( y > G_DATE_BAD_YEAR );
}
+/**
+ * g_date_valid_day:
+ * @day: day to check
+ *
+ * Returns %TRUE if the day of the month is valid (a day is valid if it's
+ * between 1 and 31 inclusive).
+ *
+ * Returns: %TRUE if the day is valid
+ */
+
gboolean
g_date_valid_day (GDateDay d)
{
return ( (d > G_DATE_BAD_DAY) && (d < 32) );
}
+/**
+ * g_date_valid_weekday:
+ * @weekday: weekday
+ *
+ * Returns %TRUE if the weekday is valid. The seven #GDateWeekday enumeration
+ * values are the only valid weekdays.
+ *
+ * Returns: %TRUE if the weekday is valid
+ */
gboolean
g_date_valid_weekday (GDateWeekday w)
{
return ( (w > G_DATE_BAD_WEEKDAY) && (w < 8) );
}
+/**
+ * g_date_valid_julian:
+ * @julian_date: Julian day to check
+ *
+ * Returns %TRUE if the Julian day is valid. Anything greater than zero
+ * is basically a valid Julian, though there is a 32-bit limit.
+ *
+ * Returns: %TRUE if the Julian day is valid
+ */
gboolean
g_date_valid_julian (guint32 j)
{
return (j > G_DATE_BAD_JULIAN);
}
+/**
+ * g_date_valid_dmy:
+ * @day: day
+ * @month: month
+ * @year: year
+ *
+ * Returns %TRUE if the day-month-year triplet forms a valid, existing day
+ * in the range of days #GDate understands (Year 1 or later, no more than
+ * a few thousand years in the future).
+ *
+ * Returns: %TRUE if the date is a valid one
+ */
gboolean
g_date_valid_dmy (GDateDay d,
GDateMonth m,
@@ -263,6 +559,14 @@ g_date_update_dmy (const GDate *const_d)
d->dmy = TRUE;
}
+/**
+ * g_date_get_weekday:
+ * @date: a #GDate
+ *
+ * Returns the day of the week for a #GDate. The date must be valid.
+ *
+ * Returns: day of the week as a #GDateWeekday.
+ */
GDateWeekday
g_date_get_weekday (const GDate *d)
{
@@ -276,6 +580,14 @@ g_date_get_weekday (const GDate *d)
return ((d->julian_days - 1) % 7) + 1;
}
+/**
+ * g_date_get_month:
+ * @date: a #GDate to get the month from
+ *
+ * Returns the month of the year. The date must be valid.
+ *
+ * Returns: month of the year as a #GDateMonth
+ */
GDateMonth
g_date_get_month (const GDate *d)
{
@@ -289,6 +601,14 @@ g_date_get_month (const GDate *d)
return d->month;
}
+/**
+ * g_date_get_year:
+ * @date: a #GDate
+ *
+ * Returns the year of a #GDate. The date must be valid.
+ *
+ * Returns: year in which the date falls
+ */
GDateYear
g_date_get_year (const GDate *d)
{
@@ -302,6 +622,14 @@ g_date_get_year (const GDate *d)
return d->year;
}
+/**
+ * g_date_get_day:
+ * @date: a #GDate to extract the day of the month from
+ *
+ * Returns the day of the month. The date must be valid.
+ *
+ * Returns: day of the month
+ */
GDateDay
g_date_get_day (const GDate *d)
{
@@ -315,6 +643,17 @@ g_date_get_day (const GDate *d)
return d->day;
}
+/**
+ * g_date_get_julian:
+ * @date: a #GDate to extract the Julian day from
+ *
+ * Returns the Julian day or "serial number" of the #GDate. The
+ * Julian day is simply the number of days since January 1, Year 1; i.e.,
+ * January 1, Year 1 is Julian day 1; January 2, Year 1 is Julian day 2,
+ * etc. The date must be valid.
+ *
+ * Returns: Julian day
+ */
guint32
g_date_get_julian (const GDate *d)
{
@@ -328,6 +667,15 @@ g_date_get_julian (const GDate *d)
return d->julian_days;
}
+/**
+ * g_date_get_day_of_year:
+ * @date: a #GDate to extract day of year from
+ *
+ * Returns the day of the year, where Jan 1 is the first day of the
+ * year. The date must be valid.
+ *
+ * Returns: day of the year
+ */
guint
g_date_get_day_of_year (const GDate *d)
{
@@ -345,6 +693,16 @@ g_date_get_day_of_year (const GDate *d)
return (days_in_year[idx][d->month] + d->day);
}
+/**
+ * g_date_get_monday_week_of_year:
+ * @date: a #GDate
+ *
+ * Returns the week of the year, where weeks are understood to start on
+ * Monday. If the date is before the first Monday of the year, return
+ * 0. The date must be valid.
+ *
+ * Returns: week of the year
+ */
guint
g_date_get_monday_week_of_year (const GDate *d)
{
@@ -369,6 +727,16 @@ g_date_get_monday_week_of_year (const GDate *d)
return ((day + wd)/7U + (wd == 0 ? 1 : 0));
}
+/**
+ * g_date_get_sunday_week_of_year:
+ * @date: a #GDate
+ *
+ * Returns the week of the year during which this date falls, if weeks
+ * are understood to being on Sunday. The date must be valid. Can return
+ * 0 if the day is before the first Sunday of the year.
+ *
+ * Returns: week number
+ */
guint
g_date_get_sunday_week_of_year (const GDate *d)
{
@@ -430,6 +798,17 @@ g_date_get_iso8601_week_of_year (const GDate *d)
return w;
}
+/**
+ * g_date_days_between:
+ * @date1: the first date
+ * @date2: the second date
+ *
+ * Computes the number of days between two dates.
+ * If @date2 is prior to @date1, the returned value is negative.
+ * Both dates must be valid.
+ *
+ * Returns: the number of days between @date1 and @date2
+ */
gint
g_date_days_between (const GDate *d1,
const GDate *d2)
@@ -440,6 +819,16 @@ g_date_days_between (const GDate *d1,
return (gint)g_date_get_julian (d2) - (gint)g_date_get_julian (d1);
}
+/**
+ * g_date_clear:
+ * @date: pointer to one or more dates to clear
+ * @n_dates: number of dates to clear
+ *
+ * Initializes one or more #GDate structs to a sane but invalid
+ * state. The cleared dates will not represent an existing date, but will
+ * not contain garbage. Useful to init a date declared on the stack.
+ * Validity can be tested with g_date_valid().
+ */
void
g_date_clear (GDate *d, guint ndates)
{
@@ -708,7 +1097,7 @@ g_date_prepare_to_parse (const gchar *str,
++i;
}
DEBUG_MSG (("**Order: %s, %s, %s", strings[0], strings[1], strings[2]));
- DEBUG_MSG (("**Sample date in this locale: `%s'", buf));
+ DEBUG_MSG (("**Sample date in this locale: '%s'", buf));
}
#endif
}
@@ -716,6 +1105,23 @@ g_date_prepare_to_parse (const gchar *str,
g_date_fill_parse_tokens (str, pt);
}
+/**
+ * g_date_set_parse:
+ * @date: a #GDate to fill in
+ * @str: string to parse
+ *
+ * Parses a user-inputted string @str, and try to figure out what date it
+ * represents, taking the [current locale][setlocale] into account. If the
+ * string is successfully parsed, the date will be valid after the call.
+ * Otherwise, it will be invalid. You should check using g_date_valid()
+ * to see whether the parsing succeeded.
+ *
+ * This function is not appropriate for file formats and the like; it
+ * isn't very precise, and its exact behavior varies with the locale.
+ * It's intended to be a heuristic routine that guesses what the user
+ * means by a given string (and it does work pretty well in that
+ * capacity).
+ */
void
g_date_set_parse (GDate *d,
const gchar *str)
@@ -732,7 +1138,7 @@ g_date_set_parse (GDate *d,
g_date_prepare_to_parse (str, &pt);
- DEBUG_MSG (("Found %d ints, `%d' `%d' `%d' and written out month %d",
+ DEBUG_MSG (("Found %d ints, '%d' '%d' '%d' and written out month %d",
pt.num_ints, pt.n[0], pt.n[1], pt.n[2], pt.month));
@@ -873,14 +1279,14 @@ g_date_set_parse (GDate *d,
/**
* g_date_set_time_t:
* @date: a #GDate
- * @timet: time_t value to set
+ * @timet: time_t value to set
*
* Sets the value of a date to the date corresponding to a time
* specified as a time_t. The time to date conversion is done using
* the user's current timezone.
*
* To set the value of a date to the current day, you could write:
- * |[
+ * |[
* g_date_set_time_t (date, time (NULL));
* ]|
*
@@ -967,6 +1373,14 @@ g_date_set_time_val (GDate *date,
g_date_set_time_t (date, (time_t) timeval->tv_sec);
}
+/**
+ * g_date_set_month:
+ * @date: a #GDate
+ * @month: month to set
+ *
+ * Sets the month of the year for a #GDate. If the resulting
+ * day-month-year triplet is invalid, the date will be invalid.
+ */
void
g_date_set_month (GDate *d,
GDateMonth m)
@@ -985,6 +1399,14 @@ g_date_set_month (GDate *d,
d->dmy = FALSE;
}
+/**
+ * g_date_set_day:
+ * @date: a #GDate
+ * @day: day to set
+ *
+ * Sets the day of the month for a #GDate. If the resulting
+ * day-month-year triplet is invalid, the date will be invalid.
+ */
void
g_date_set_day (GDate *d,
GDateDay day)
@@ -1003,6 +1425,14 @@ g_date_set_day (GDate *d,
d->dmy = FALSE;
}
+/**
+ * g_date_set_year:
+ * @date: a #GDate
+ * @year: year to set
+ *
+ * Sets the year for a #GDate. If the resulting day-month-year
+ * triplet is invalid, the date will be invalid.
+ */
void
g_date_set_year (GDate *d,
GDateYear y)
@@ -1021,6 +1451,18 @@ g_date_set_year (GDate *d,
d->dmy = FALSE;
}
+/**
+ * g_date_set_dmy:
+ * @date: a #GDate
+ * @day: day
+ * @month: month
+ * @y: year
+ *
+ * Sets the value of a #GDate from a day, month, and year.
+ * The day-month-year triplet must be valid; if you aren't
+ * sure it is, call g_date_valid_dmy() to check before you
+ * set it.
+ */
void
g_date_set_dmy (GDate *d,
GDateDay day,
@@ -1039,6 +1481,13 @@ g_date_set_dmy (GDate *d,
d->dmy = TRUE;
}
+/**
+ * g_date_set_julian:
+ * @date: a #GDate
+ * @julian_date: Julian day number (days since January 1, Year 1)
+ *
+ * Sets the value of a #GDate from a Julian day number.
+ */
void
g_date_set_julian (GDate *d,
guint32 j)
@@ -1051,7 +1500,15 @@ g_date_set_julian (GDate *d,
d->dmy = FALSE;
}
-
+/**
+ * g_date_is_first_of_month:
+ * @date: a #GDate to check
+ *
+ * Returns %TRUE if the date is on the first of a month.
+ * The date must be valid.
+ *
+ * Returns: %TRUE if the date is the first of the month
+ */
gboolean
g_date_is_first_of_month (const GDate *d)
{
@@ -1066,6 +1523,15 @@ g_date_is_first_of_month (const GDate *d)
else return FALSE;
}
+/**
+ * g_date_is_last_of_month:
+ * @date: a #GDate to check
+ *
+ * Returns %TRUE if the date is the last day of the month.
+ * The date must be valid.
+ *
+ * Returns: %TRUE if the date is the last day of the month
+ */
gboolean
g_date_is_last_of_month (const GDate *d)
{
@@ -1084,6 +1550,15 @@ g_date_is_last_of_month (const GDate *d)
else return FALSE;
}
+/**
+ * g_date_add_days:
+ * @date: a #GDate to increment
+ * @n_days: number of days to move the date forward
+ *
+ * Increments a date some number of days.
+ * To move forward by weeks, add weeks*7 days.
+ * The date must be valid.
+ */
void
g_date_add_days (GDate *d,
guint ndays)
@@ -1099,6 +1574,15 @@ g_date_add_days (GDate *d,
d->dmy = FALSE;
}
+/**
+ * g_date_subtract_days:
+ * @date: a #GDate to decrement
+ * @n_days: number of days to move
+ *
+ * Moves a date some number of days into the past.
+ * To move by weeks, just move by weeks*7 days.
+ * The date must be valid.
+ */
void
g_date_subtract_days (GDate *d,
guint ndays)
@@ -1115,6 +1599,17 @@ g_date_subtract_days (GDate *d,
d->dmy = FALSE;
}
+/**
+ * g_date_add_months:
+ * @date: a #GDate to increment
+ * @n_months: number of months to move forward
+ *
+ * Increments a date by some number of months.
+ * If the day of the month is greater than 28,
+ * this routine may change the day of the month
+ * (because the destination month may not have
+ * the current day in it). The date must be valid.
+ */
void
g_date_add_months (GDate *d,
guint nmonths)
@@ -1147,6 +1642,16 @@ g_date_add_months (GDate *d,
g_return_if_fail (g_date_valid (d));
}
+/**
+ * g_date_subtract_months:
+ * @date: a #GDate to decrement
+ * @n_months: number of months to move
+ *
+ * Moves a date some number of months into the past.
+ * If the current day of the month doesn't exist in
+ * the destination month, the day of the month
+ * may change. The date must be valid.
+ */
void
g_date_subtract_months (GDate *d,
guint nmonths)
@@ -1186,6 +1691,16 @@ g_date_subtract_months (GDate *d,
g_return_if_fail (g_date_valid (d));
}
+/**
+ * g_date_add_years:
+ * @date: a #GDate to increment
+ * @n_years: number of years to move forward
+ *
+ * Increments a date by some number of years.
+ * If the date is February 29, and the destination
+ * year is not a leap year, the date will be changed
+ * to February 28. The date must be valid.
+ */
void
g_date_add_years (GDate *d,
guint nyears)
@@ -1208,6 +1723,17 @@ g_date_add_years (GDate *d,
d->julian = FALSE;
}
+/**
+ * g_date_subtract_years:
+ * @date: a #GDate to decrement
+ * @n_years: number of years to move
+ *
+ * Moves a date some number of years into the past.
+ * If the current day doesn't exist in the destination
+ * year (i.e. it's February 29 and you move to a non-leap-year)
+ * then the day is changed to February 29. The date
+ * must be valid.
+ */
void
g_date_subtract_years (GDate *d,
guint nyears)
@@ -1231,6 +1757,19 @@ g_date_subtract_years (GDate *d,
d->julian = FALSE;
}
+/**
+ * g_date_is_leap_year:
+ * @year: year to check
+ *
+ * Returns %TRUE if the year is a leap year.
+ *
+ * For the purposes of this function, leap year is every year
+ * divisible by 4 unless that year is divisible by 100. If it
+ * is divisible by 100 it would be a leap year only if that year
+ * is also divisible by 400.
+ *
+ * Returns: %TRUE if the year is a leap year
+ */
gboolean
g_date_is_leap_year (GDateYear year)
{
@@ -1240,6 +1779,16 @@ g_date_is_leap_year (GDateYear year)
(year % 400) == 0 );
}
+/**
+ * g_date_get_days_in_month:
+ * @month: month
+ * @year: year
+ *
+ * Returns the number of days in a month, taking leap
+ * years into account.
+ *
+ * Returns: number of days in @month during the @year
+ */
guint8
g_date_get_days_in_month (GDateMonth month,
GDateYear year)
@@ -1254,6 +1803,20 @@ g_date_get_days_in_month (GDateMonth month,
return days_in_months[idx][month];
}
+/**
+ * g_date_get_monday_weeks_in_year:
+ * @year: a year
+ *
+ * Returns the number of weeks in the year, where weeks
+ * are taken to start on Monday. Will be 52 or 53. The
+ * date must be valid. (Years always have 52 7-day periods,
+ * plus 1 or 2 extra days depending on whether it's a leap
+ * year. This function is basically telling you how many
+ * Mondays are in the year, i.e. there are 53 Mondays if
+ * one of the extra days happens to be a Monday.)
+ *
+ * Returns: number of Mondays in the year
+ */
guint8
g_date_get_monday_weeks_in_year (GDateYear year)
{
@@ -1276,6 +1839,20 @@ g_date_get_monday_weeks_in_year (GDateYear year)
return 52;
}
+/**
+ * g_date_get_sunday_weeks_in_year:
+ * @year: year to count weeks in
+ *
+ * Returns the number of weeks in the year, where weeks
+ * are taken to start on Sunday. Will be 52 or 53. The
+ * date must be valid. (Years always have 52 7-day periods,
+ * plus 1 or 2 extra days depending on whether it's a leap
+ * year. This function is basically telling you how many
+ * Sundays are in the year, i.e. there are 53 Sundays if
+ * one of the extra days happens to be a Sunday.)
+ *
+ * Returns: the number of weeks in @year
+ */
guint8
g_date_get_sunday_weeks_in_year (GDateYear year)
{
@@ -1298,6 +1875,17 @@ g_date_get_sunday_weeks_in_year (GDateYear year)
return 52;
}
+/**
+ * g_date_compare:
+ * @lhs: first date to compare
+ * @rhs: second date to compare
+ *
+ * qsort()-style comparison function for dates.
+ * Both dates must be valid.
+ *
+ * Returns: 0 for equal, less than zero if @lhs is less than @rhs,
+ * greater than zero if @lhs is greater than @rhs
+ */
gint
g_date_compare (const GDate *lhs,
const GDate *rhs)
@@ -1347,7 +1935,14 @@ g_date_compare (const GDate *lhs,
return 0; /* warnings */
}
-
+/**
+ * g_date_to_struct_tm:
+ * @date: a #GDate to set the struct tm from
+ * @tm: struct tm to fill
+ *
+ * Fills in the date-related bits of a struct tm using the @date value.
+ * Initializes the non-date parts with something sane but meaningless.
+ */
void
g_date_to_struct_tm (const GDate *d,
struct tm *tm)
@@ -1385,6 +1980,18 @@ g_date_to_struct_tm (const GDate *d,
tm->tm_isdst = -1; /* -1 means "information not available" */
}
+/**
+ * g_date_clamp:
+ * @date: a #GDate to clamp
+ * @min_date: minimum accepted value for @date
+ * @max_date: maximum accepted value for @date
+ *
+ * If @date is prior to @min_date, sets @date equal to @min_date.
+ * If @date falls after @max_date, sets @date equal to @max_date.
+ * Otherwise, @date is unchanged.
+ * Either of @min_date and @max_date may be %NULL.
+ * All non-%NULL dates must be valid.
+ */
void
g_date_clamp (GDate *date,
const GDate *min_date,
@@ -1408,6 +2015,14 @@ g_date_clamp (GDate *date,
*date = *max_date;
}
+/**
+ * g_date_order:
+ * @date1: the first date
+ * @date2: the second date
+ *
+ * Checks if @date1 is less than or equal to @date2,
+ * and swap the values if this is not the case.
+ */
void
g_date_order (GDate *date1,
GDate *date2)
@@ -1801,6 +2416,29 @@ win32_strftime_helper (const GDate *d,
#endif
+/**
+ * g_date_strftime:
+ * @s: destination buffer
+ * @slen: buffer size
+ * @format: format string
+ * @date: valid #GDate
+ *
+ * Generates a printed representation of the date, in a
+ * [locale][setlocale]-specific way.
+ * Works just like the platform's C library strftime() function,
+ * but only accepts date-related formats; time-related formats
+ * give undefined results. Date must be valid. Unlike strftime()
+ * (which uses the locale encoding), works on a UTF-8 format
+ * string and stores a UTF-8 result.
+ *
+ * This function does not provide any conversion specifiers in
+ * addition to those implemented by the platform's C library.
+ * For example, don't expect that using g_date_strftime() would
+ * make the \%F provided by the C99 strftime() work on Windows
+ * where the C library only complies to C89.
+ *
+ * Returns: number of characters written to the buffer, or 0 the buffer was too small
+ */
gsize
g_date_strftime (gchar *s,
gsize slen,