From 6466c2f6d51414464a0aa32e31a151ce6b148d33 Mon Sep 17 00:00:00 2001 From: Arturo Espinosa Date: Thu, 13 Aug 1998 01:13:11 +0000 Subject: More work on the month view - Federico svn path=/trunk/; revision=312 --- calendar/gnome-month-item.c | 140 +++++++++++++++++++++++++++++++++++++++----- 1 file changed, 124 insertions(+), 16 deletions(-) (limited to 'calendar/gnome-month-item.c') diff --git a/calendar/gnome-month-item.c b/calendar/gnome-month-item.c index 0f5aea462c..f5e3a5b8df 100644 --- a/calendar/gnome-month-item.c +++ b/calendar/gnome-month-item.c @@ -44,7 +44,9 @@ static int sept_1752[42] = { #define REFORMATION_DAY 639787 /* First day of the reformation, counted from 1 Jan 1 */ #define MISSING_DAYS 11 /* They corrected out 11 days */ #define THURSDAY 4 /* First day of reformation */ -#define SATURDAY 6 +#define SATURDAY 6 /* Offset value; 1 Jan 1 was a Saturday */ +#define SEPT_1752_START 2 /* Start day within month */ +#define SEPT_1752_END 20 /* End day within month */ enum { @@ -313,21 +315,136 @@ create_headings (GnomeMonthItem *mitem) } } +/* Returns the number of leap years since year 1 up to (but not including) the specified year */ +static int +leap_years_up_to (int year) +{ + return (year / 4 /* trivial leapness */ + - ((year > 1700) ? (year / 100 - 17) : 0) /* minus centuries since 1700 */ + + ((year > 1600) ? ((year - 1600) / 400) : 0)); /* plus centuries since 1700 divisible by 400 */ +} + +/* Returns whether the specified year is a leap year */ +static int +is_leap_year (int year) +{ + if (year <= 1752) + return !(year % 4); + else + return (!(year % 4) && (year % 100)) || !(year % 400); +} + +/* Returns the 1-based day number within the year of the specified date */ +static int +day_in_year (int day, int month, int year) +{ + int is_leap, i; + + is_leap = is_leap_year (year); + + for (i = 0; i < month; i++) + day += days_in_month [is_leap][i]; + + return day; +} + +/* Returns the day of the week (zero-based, zero is Sunday) for the specified date. For the days + * that were removed on the Gregorian reformation, it returns Thursday. + */ +static int +day_in_week (int day, int month, int year) +{ + int n; + + n = (year - 1) * 365 + leap_years_up_to (year - 1) + day_in_year (day, month, year); + + if (n < REFORMATION_DAY) + return (n - 1 + SATURDAY) % 7; + + if (n >= (REFORMATION_DAY + MISSING_DAYS)) + return (n - 1 + SATURDAY - MISSING_DAYS) % 7; + + return THURSDAY; +} + +/* Fills the 42-element days array with the day numbers for the specified month. Slots outside the + * bounds of the month are filled with zeros. The starting and ending indexes of the days are + * returned in the start and end arguments. + */ +static void +build_month (int month, int year, int *days, int *start, int *end) +{ + int i; + int d_month, d_week; + + /* Note that months are zero-based, so September is month 8 */ + + if ((year == 1752) && (month == 8)) { + memcpy (days, sept_1752, 42 * sizeof (int)); + + if (start) + *start = SEPT_1752_START; + + if (end) + *end = SEPT_1752_END; + + return; + } + + for (i = 0; i < 42; i++) + days[i] = 0; + + d_month = days_in_month[is_leap_year (year)][month]; + d_week = day_in_week (1, month, year); + + for (i = 0; i < d_month; i++) + days[d_week + i] = i + 1; + + if (start) + *start = d_week; + + if (end) + *end = d_week + d_month - 1; +} + /* Set the day numbers in the monthly calendar */ static void set_days (GnomeMonthItem *mitem) { - int i; + int i, ofs; + int days[42]; + int start, end; char buf[100]; - /* FIXME: actually calculate the numbers */ + build_month (mitem->month, mitem->year, days, &start, &end); - for (i = 0; i < 42; i++) { - sprintf (buf, "%d", i); + if (mitem->start_on_monday) + ofs = (start + 6) % 7; + else + ofs = start; + + /* Clear days before start of month */ + + for (i = 0; i < ofs; i++) + gnome_canvas_item_set (mitem->items[ITEM_DAY_LABEL + i], + "text", NULL, + NULL); + + /* Set days of month */ + + for (; start <= end; start++, i++) { + sprintf (buf, "%d", days[start]); gnome_canvas_item_set (mitem->items[ITEM_DAY_LABEL + i], "text", buf, NULL); } + + /* Clear days after end of month */ + + for (; i < 42; i++) + gnome_canvas_item_set (mitem->items[ITEM_DAY_LABEL + i], + "text", NULL, + NULL); } /* Creates the items for the days */ @@ -369,16 +486,6 @@ create_days (GnomeMonthItem *mitem) set_days (mitem); } -/* Returns a normalized day index (as in sunday to saturday) based on a visible day index */ -static int -get_day_index (GnomeMonthItem *mitem, int draw_index) -{ - if (mitem->start_on_monday) - return (draw_index + 1) % 7; - else - return draw_index; -} - /* Resets the text of the day name headings */ static void set_day_names (GnomeMonthItem *mitem) @@ -387,7 +494,7 @@ set_day_names (GnomeMonthItem *mitem) for (i = 0; i < 7; i++) gnome_canvas_item_set (mitem->items[ITEM_HEAD_LABEL + i], - "text", mitem->day_names[get_day_index (mitem, i)], + "text", mitem->day_names[mitem->start_on_monday ? ((i + 1) % 7) : i], NULL); } @@ -660,6 +767,7 @@ gnome_month_item_set_arg (GtkObject *object, GtkArg *arg, guint arg_id) case ARG_START_ON_MONDAY: mitem->start_on_monday = GTK_VALUE_BOOL (*arg); set_day_names (mitem); + set_days (mitem); break; default: -- cgit v1.2.3