err.no Git - scalable-opengroupware.org/blob - SOPE/NGCards/iCalWeeklyRecurrenceCalculator.m

   1 /*
   2   Copyright (C) 2004-2005 SKYRIX Software AG
   3
   4   This file is part of SOPE.
   5
   6   SOPE is free software; you can redistribute it and/or modify it under
   7   the terms of the GNU Lesser General Public License as published by the
   8   Free Software Foundation; either version 2, or (at your option) any
   9   later version.
  10
  11   SOPE is distributed in the hope that it will be useful, but WITHOUT ANY
  12   WARRANTY; without even the implied warranty of MERCHANTABILITY or
  13   FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  14   License for more details.
  15
  16   You should have received a copy of the GNU Lesser General Public
  17   License along with SOPE; see the file COPYING.  If not, write to the
  18   Free Software Foundation, 59 Temple Place - Suite 330, Boston, MA
  19   02111-1307, USA.
  20 */
  21
  22 #import <NGExtensions/NSCalendarDate+misc.h>
  23
  24 #import "iCalRecurrenceCalculator.h"
  25
  26 @interface iCalWeeklyRecurrenceCalculator : iCalRecurrenceCalculator
  27 @end
  28
  29 #import <NGExtensions/NGCalendarDateRange.h>
  30 #import "iCalRecurrenceRule.h"
  31 #import "NSCalendarDate+ICal.h"
  32
  33 @interface iCalRecurrenceCalculator (PrivateAPI)
  34
  35 - (NSCalendarDate *)lastInstanceStartDate;
  36
  37 - (unsigned)offsetFromSundayForJulianNumber:(long)_jn;
  38 - (unsigned)offsetFromSundayForWeekDay:(iCalWeekDay)_weekDay;
  39 - (unsigned)offsetFromSundayForCurrentWeekStart;
  40
  41 - (iCalWeekDay)weekDayForJulianNumber:(long)_jn;
  42
  43 @end
  44
  45 /*
  46    TODO: If BYDAY is specified, lastInstanceStartDate and recurrences will
  47          differ significantly!
  48 */
  49 @implementation iCalWeeklyRecurrenceCalculator
  50
  51 - (NSArray *)recurrenceRangesWithinCalendarDateRange:(NGCalendarDateRange *)_r {
  52   NSMutableArray *ranges;
  53   NSCalendarDate *firStart;
  54   long           i, jnFirst, jnStart, jnEnd, startEndCount;
  55   unsigned       interval, byDayMask;
  56
  57   firStart = [self->firstRange startDate];
  58   jnFirst  = [firStart julianNumber];
  59   jnEnd    = [[_r endDate] julianNumber];
  60
  61   if (jnFirst > jnEnd)
  62     return nil;
  63
  64   jnStart  = [[_r startDate] julianNumber];
  65   interval = [self->rrule repeatInterval];
  66
  67   /* if rule is bound, check the bounds */
  68   if (![self->rrule isInfinite]) {
  69     NSCalendarDate *until;
  70     long           jnRuleLast;
  71
  72     until = [self->rrule untilDate];
  73     if (until) {
  74       if ([until compare:[_r startDate]] == NSOrderedAscending)
  75         return nil;
  76       jnRuleLast = [until julianNumber];
  77     }
  78     else {
  79       jnRuleLast = (interval * [self->rrule repeatCount] * 7)
  80       + jnFirst;
  81       if (jnRuleLast < jnStart)
  82         return nil;
  83     }
  84     /* jnStart < jnRuleLast < jnEnd ? */
  85     if (jnEnd > jnRuleLast)
  86       jnEnd = jnRuleLast;
  87   }
  88
  89   startEndCount = (jnEnd - jnStart) + 1;
  90   ranges        = [NSMutableArray arrayWithCapacity:startEndCount];
  91   byDayMask     = [self->rrule byDayMask];
  92   if (!byDayMask) {
  93     for (i = 0 ; i < startEndCount; i++) {
  94       long jnCurrent;
  95
  96       jnCurrent = jnStart + i;
  97       if (jnCurrent >= jnFirst) {
  98         long jnDiff;
  99
 100         jnDiff = jnCurrent - jnFirst; /* difference in days */
 101         if ((jnDiff % (interval * 7)) == 0) {
 102           NSCalendarDate      *start, *end;
 103           NGCalendarDateRange *r;
 104
 105           start = [NSCalendarDate dateForJulianNumber:jnCurrent];
 106           [start setTimeZone:[firStart timeZone]];
 107           start = [start hour:  [firStart hourOfDay]
 108                          minute:[firStart minuteOfHour]
 109                          second:[firStart secondOfMinute]];
 110           end   = [start addTimeInterval:[self->firstRange duration]];
 111           r     = [NGCalendarDateRange calendarDateRangeWithStartDate:start
 112                                        endDate:end];
 113           if ([_r containsDateRange:r])
 114             [ranges addObject:r];
 115         }
 116       }
 117     }
 118   }
 119   else {
 120     long jnFirstWeekStart, weekStartOffset;
 121
 122     /* calculate jnFirst's week start - this depends on our setting of week
 123        start */
 124     weekStartOffset = [self offsetFromSundayForJulianNumber:jnFirst] -
 125                       [self offsetFromSundayForCurrentWeekStart];
 126
 127     jnFirstWeekStart = jnFirst - weekStartOffset;
 128
 129     for (i = 0 ; i < startEndCount; i++) {
 130       long jnCurrent;
 131
 132       jnCurrent = jnStart + i;
 133       if (jnCurrent >= jnFirst) {
 134         long jnDiff;
 135
 136         /* we need to calculate a difference in weeks */
 137         jnDiff = (jnCurrent - jnFirstWeekStart) % 7;
 138         if ((jnDiff % interval) == 0) {
 139           BOOL isRecurrence = NO;
 140
 141           if (jnCurrent == jnFirst) {
 142             isRecurrence = YES;
 143           }
 144           else {
 145             iCalWeekDay weekDay;
 146
 147             weekDay = [self weekDayForJulianNumber:jnCurrent];
 148             isRecurrence = (weekDay & [self->rrule byDayMask]) ? YES : NO;
 149           }
 150           if (isRecurrence) {
 151             NSCalendarDate      *start, *end;
 152             NGCalendarDateRange *r;
 153
 154             start = [NSCalendarDate dateForJulianNumber:jnCurrent];
 155             [start setTimeZone:[firStart timeZone]];
 156             start = [start hour:  [firStart hourOfDay]
 157                            minute:[firStart minuteOfHour]
 158                            second:[firStart secondOfMinute]];
 159             end   = [start addTimeInterval:[self->firstRange duration]];
 160             r     = [NGCalendarDateRange calendarDateRangeWithStartDate:start
 161                                          endDate:end];
 162             if ([_r containsDateRange:r])
 163               [ranges addObject:r];
 164           }
 165         }
 166       }
 167     }
 168   }
 169   return ranges;
 170 }
 171
 172 - (NSCalendarDate *)lastInstanceStartDate {
 173   if ([self->rrule repeatCount] > 0) {
 174     long           jnFirst, jnRuleLast;
 175     NSCalendarDate *firStart, *until;
 176
 177     firStart   = [self->firstRange startDate];
 178     jnFirst    = [firStart julianNumber];
 179     jnRuleLast = ([self->rrule repeatInterval] *
 180                   [self->rrule repeatCount] * 7) +
 181                   jnFirst;
 182     until      = [NSCalendarDate dateForJulianNumber:jnRuleLast];
 183     until      = [until hour:  [firStart hourOfDay]
 184                         minute:[firStart minuteOfHour]
 185                         second:[firStart secondOfMinute]];
 186     return until;
 187   }
 188   return [super lastInstanceStartDate];
 189 }
 190
 191 @end /* iCalWeeklyRecurrenceCalculator */