err.no Git - sope/blob - sope-ical/NGiCal/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 #include "iCalRecurrenceCalculator.h"
  23
  24 @interface iCalWeeklyRecurrenceCalculator : iCalRecurrenceCalculator
  25 @end
  26
  27 #include <NGExtensions/NGCalendarDateRange.h>
  28 #include "iCalRecurrenceRule.h"
  29 #include "NSCalendarDate+ICal.h"
  30 #include "common.h"
  31
  32 @interface iCalRecurrenceCalculator (PrivateAPI)
  33
  34 - (NSCalendarDate *)lastInstanceStartDate;
  35
  36 - (unsigned)offsetFromSundayForJulianNumber:(long)_jn;
  37 - (unsigned)offsetFromSundayForWeekDay:(iCalWeekDay)_weekDay;
  38 - (unsigned)offsetFromSundayForCurrentWeekStart;
  39
  40 - (iCalWeekDay)weekDayForJulianNumber:(long)_jn;
  41
  42 @end
  43
  44 /*
  45    TODO: If BYDAY is specified, lastInstanceStartDate and recurrences will
  46          differ significantly!
  47 */
  48 @implementation iCalWeeklyRecurrenceCalculator
  49
  50 - (NSArray *)recurrenceRangesWithinCalendarDateRange:(NGCalendarDateRange *)_r {
  51   NSMutableArray *ranges;
  52   NSCalendarDate *firStart;
  53   long           i, jnFirst, jnStart, jnEnd, startEndCount;
  54   unsigned       interval, byDayMask;
  55
  56   firStart = [self->firstRange startDate];
  57   jnFirst  = [firStart julianNumber];
  58   jnEnd    = [[_r endDate] julianNumber];
  59
  60   if (jnFirst > jnEnd)
  61     return nil;
  62
  63   jnStart  = [[_r startDate] julianNumber];
  64   interval = [self->rrule repeatInterval];
  65
  66   /* if rule is bound, check the bounds */
  67   if (![self->rrule isInfinite]) {
  68     NSCalendarDate *until;
  69     long           jnRuleLast;
  70
  71     until = [self->rrule untilDate];
  72     if (until) {
  73       if ([until compare:[_r startDate]] == NSOrderedAscending)
  74         return nil;
  75       jnRuleLast = [until julianNumber];
  76     }
  77     else {
  78       jnRuleLast = (interval * [self->rrule repeatCount] * 7)
  79       + jnFirst;
  80       if (jnRuleLast < jnStart)
  81         return nil;
  82     }
  83     /* jnStart < jnRuleLast < jnEnd ? */
  84     if (jnEnd > jnRuleLast)
  85       jnEnd = jnRuleLast;
  86   }
  87
  88   startEndCount = (jnEnd - jnStart) + 1;
  89   ranges        = [NSMutableArray arrayWithCapacity:startEndCount];
  90   byDayMask     = [self->rrule byDayMask];
  91   if (!byDayMask) {
  92     for (i = 0 ; i < startEndCount; i++) {
  93       long jnCurrent;
  94
  95       jnCurrent = jnStart + i;
  96       if (jnCurrent >= jnFirst) {
  97         long jnDiff;
  98
  99         jnDiff = jnCurrent - jnFirst; /* difference in days */
 100         if ((jnDiff % (interval * 7)) == 0) {
 101           NSCalendarDate      *start, *end;
 102           NGCalendarDateRange *r;
 103
 104           start = [NSCalendarDate dateForJulianNumber:jnCurrent];
 105           [start setTimeZone:[firStart timeZone]];
 106           start = [start hour:  [firStart hourOfDay]
 107                          minute:[firStart minuteOfHour]
 108                          second:[firStart secondOfMinute]];
 109           end   = [start addTimeInterval:[self->firstRange duration]];
 110           r     = [NGCalendarDateRange calendarDateRangeWithStartDate:start
 111                                        endDate:end];
 112           if ([_r containsDateRange:r])
 113             [ranges addObject:r];
 114         }
 115       }
 116     }
 117   }
 118   else {
 119     long jnFirstWeekStart, weekStartOffset;
 120
 121     /* calculate jnFirst's week start - this depends on our setting of week
 122        start */
 123     weekStartOffset = [self offsetFromSundayForJulianNumber:jnFirst] -
 124                       [self offsetFromSundayForCurrentWeekStart];
 125
 126     jnFirstWeekStart = jnFirst - weekStartOffset;
 127
 128     for (i = 0 ; i < startEndCount; i++) {
 129       long jnCurrent;
 130
 131       jnCurrent = jnStart + i;
 132       if (jnCurrent >= jnFirst) {
 133         long jnDiff;
 134
 135         /* we need to calculate a difference in weeks */
 136         jnDiff = (jnCurrent - jnFirstWeekStart) % 7;
 137         if ((jnDiff % interval) == 0) {
 138           BOOL isRecurrence = NO;
 139
 140           if (jnCurrent == jnFirst) {
 141             isRecurrence = YES;
 142           }
 143           else {
 144             iCalWeekDay weekDay;
 145
 146             weekDay = [self weekDayForJulianNumber:jnCurrent];
 147             isRecurrence = (weekDay & [self->rrule byDayMask]) ? YES : NO;
 148           }
 149           if (isRecurrence) {
 150             NSCalendarDate      *start, *end;
 151             NGCalendarDateRange *r;
 152
 153             start = [NSCalendarDate dateForJulianNumber:jnCurrent];
 154             [start setTimeZone:[firStart timeZone]];
 155             start = [start hour:  [firStart hourOfDay]
 156                            minute:[firStart minuteOfHour]
 157                            second:[firStart secondOfMinute]];
 158             end   = [start addTimeInterval:[self->firstRange duration]];
 159             r     = [NGCalendarDateRange calendarDateRangeWithStartDate:start
 160                                          endDate:end];
 161             if ([_r containsDateRange:r])
 162               [ranges addObject:r];
 163           }
 164         }
 165       }
 166     }
 167   }
 168   return ranges;
 169 }
 170
 171 - (NSCalendarDate *)lastInstanceStartDate {
 172   if ([self->rrule repeatCount] > 0) {
 173     long           jnFirst, jnRuleLast;
 174     NSCalendarDate *firStart, *until;
 175
 176     firStart   = [self->firstRange startDate];
 177     jnFirst    = [firStart julianNumber];
 178     jnRuleLast = ([self->rrule repeatInterval] *
 179                   [self->rrule repeatCount] * 7) +
 180                   jnFirst;
 181     until      = [NSCalendarDate dateForJulianNumber:jnRuleLast];
 182     until      = [until hour:  [firStart hourOfDay]
 183                         minute:[firStart minuteOfHour]
 184                         second:[firStart secondOfMinute]];
 185     return until;
 186   }
 187   return [super lastInstanceStartDate];
 188 }
 189
 190 @end /* iCalWeeklyRecurrenceCalculator */