err.no Git - sope/blob - sope-ical/NGiCal/iCalRecurrenceCalculator.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 #include <NGExtensions/NGCalendarDateRange.h>
  24 #include "iCalRecurrenceRule.h"
  25 #include "NSCalendarDate+ICal.h"
  26 #include "common.h"
  27
  28 /* class cluster */
  29
  30
  31 /* Private */
  32
  33 @interface iCalRecurrenceCalculator (PrivateAPI)
  34 - (NSCalendarDate *)lastInstanceStartDate;
  35
  36 - (unsigned)offsetFromSundayForJulianNumber:(long)_jn;
  37 - (unsigned)offsetFromSundayForWeekDay:(iCalWeekDay)_weekDay;
  38 - (unsigned)offsetFromSundayForCurrentWeekStart;
  39
  40 - (iCalWeekDay)weekDayForJulianNumber:(long)_jn;
  41 @end
  42
  43 @implementation iCalRecurrenceCalculator
  44
  45 static Class NSCalendarDateClass     = Nil;
  46 static Class iCalRecurrenceRuleClass = Nil;
  47 static Class dailyCalcClass   = Nil;
  48 static Class weeklyCalcClass  = Nil;
  49 static Class monthlyCalcClass = Nil;
  50 static Class yearlyCalcClass  = Nil;
  51
  52 + (void)initialize {
  53   static BOOL didInit = NO;
  54
  55   if (didInit) return;
  56   didInit = YES;
  57
  58   NSCalendarDateClass     = [NSCalendarDate class];
  59   iCalRecurrenceRuleClass = [iCalRecurrenceRule class];
  60
  61   dailyCalcClass   = NSClassFromString(@"iCalDailyRecurrenceCalculator");
  62   weeklyCalcClass  = NSClassFromString(@"iCalWeeklyRecurrenceCalculator");
  63   monthlyCalcClass = NSClassFromString(@"iCalMonthlyRecurrenceCalculator");
  64   yearlyCalcClass  = NSClassFromString(@"iCalYearlyRecurrenceCalculator");
  65 }
  66
  67 /* factory */
  68
  69 + (id)recurrenceCalculatorForRecurrenceRule:(iCalRecurrenceRule *)_rrule
  70          withFirstInstanceCalendarDateRange:(NGCalendarDateRange *)_range
  71 {
  72   return [[[self alloc] initWithRecurrenceRule:_rrule
  73                         firstInstanceCalendarDateRange:_range] autorelease];
  74 }
  75
  76 /* complex calculation convenience */
  77
  78 + (NSArray *)recurrenceRangesWithinCalendarDateRange:(NGCalendarDateRange *)_r
  79   firstInstanceCalendarDateRange:(NGCalendarDateRange *)_fir
  80   recurrenceRules:(NSArray *)_rRules
  81   exceptionRules:(NSArray *)_exRules
  82   exceptionDates:(NSArray *)_exDates
  83 {
  84   id                       rule;
  85   iCalRecurrenceCalculator *calc;
  86   NSMutableArray           *ranges;
  87   NSMutableArray           *exDates;
  88   unsigned                 i, count, rCount;
  89
  90   ranges = [NSMutableArray array];
  91   count  = [_rRules count];
  92   for (i = 0; i < count; i++) {
  93     NSArray *rs;
  94
  95     rule = [_rRules objectAtIndex:i];
  96     if (![rule isKindOfClass:iCalRecurrenceRuleClass])
  97       rule = [iCalRecurrenceRule recurrenceRuleWithICalRepresentation:rule];
  98
  99     calc = [self recurrenceCalculatorForRecurrenceRule:rule
 100                  withFirstInstanceCalendarDateRange:_fir];
 101     rs   = [calc recurrenceRangesWithinCalendarDateRange:_r];
 102     [ranges addObjectsFromArray:rs];
 103   }
 104
 105   if (![ranges count])
 106     return nil;
 107
 108   /* test if any exceptions do match */
 109   count = [_exRules count];
 110   for (i = 0; i < count; i++) {
 111     NSArray *rs;
 112
 113     rule = [_exRules objectAtIndex:i];
 114     if (![rule isKindOfClass:iCalRecurrenceRuleClass])
 115       rule = [iCalRecurrenceRule recurrenceRuleWithICalRepresentation:rule];
 116
 117     calc = [self recurrenceCalculatorForRecurrenceRule:rule
 118                  withFirstInstanceCalendarDateRange:_fir];
 119     rs   = [calc recurrenceRangesWithinCalendarDateRange:_r];
 120     [ranges removeObjectsInArray:rs];
 121   }
 122
 123   if (![ranges count])
 124     return nil;
 125
 126   /* exception dates */
 127
 128   count  = [_exDates count];
 129   if (!count) return ranges;
 130
 131   /* sort out exDates not within range */
 132
 133   exDates = [NSMutableArray arrayWithCapacity:count];
 134   for (i = 0; i < count; i++) {
 135     id exDate;
 136
 137     exDate = [_exDates objectAtIndex:i];
 138     if (![exDate isKindOfClass:NSCalendarDateClass]) {
 139       exDate = [NSCalendarDate calendarDateWithICalRepresentation:exDate];
 140     }
 141     if ([_r containsDate:exDate])
 142       [exDates addObject:exDate];
 143   }
 144
 145   /* remove matching exDates from ranges */
 146
 147   count  = [exDates count];
 148   if (!count) return ranges;
 149
 150   rCount = [ranges count];
 151   for (i = 0; i < count; i++) {
 152     NSCalendarDate      *exDate;
 153     NGCalendarDateRange *r;
 154     unsigned            k;
 155
 156     exDate = [exDates objectAtIndex:i];
 157     for (k = 0; k < rCount; k++) {
 158       unsigned rIdx;
 159
 160       rIdx = (rCount - k) - 1;
 161       r    = [ranges objectAtIndex:rIdx];
 162       if ([r containsDate:exDate]) {
 163         [ranges removeObjectAtIndex:rIdx];
 164         rCount--;
 165         break; /* this is safe because we know that ranges don't overlap */
 166       }
 167     }
 168   }
 169   return ranges;
 170 }
 171
 172
 173 /* init */
 174
 175 - (id)initWithRecurrenceRule:(iCalRecurrenceRule *)_rrule
 176   firstInstanceCalendarDateRange:(NGCalendarDateRange *)_range
 177 {
 178   iCalRecurrenceFrequency freq;
 179   Class calcClass = Nil;
 180
 181   freq = [_rrule frequency];
 182   if (freq == iCalRecurrenceFrequenceDaily)
 183     calcClass = dailyCalcClass;
 184   else if (freq == iCalRecurrenceFrequenceWeekly)
 185     calcClass = weeklyCalcClass;
 186   else if (freq == iCalRecurrenceFrequenceMonthly)
 187     calcClass = monthlyCalcClass;
 188   else if (freq == iCalRecurrenceFrequenceYearly)
 189     calcClass = yearlyCalcClass;
 190
 191   [self autorelease];
 192   if (calcClass == Nil)
 193     return nil;
 194
 195   self = [[calcClass alloc] init];
 196   ASSIGN(self->rrule, _rrule);
 197   ASSIGN(self->firstRange, _range);
 198   return self;
 199 }
 200
 201 /* dealloc */
 202
 203 - (void)dealloc {
 204   [self->firstRange release];
 205   [self->rrule      release];
 206   [super dealloc];
 207 }
 208
 209 /* helpers */
 210
 211 - (unsigned)offsetFromSundayForJulianNumber:(long)_jn {
 212   return (unsigned)((int)(_jn + 1.5)) % 7;
 213 }
 214
 215 - (unsigned)offsetFromSundayForWeekDay:(iCalWeekDay)_weekDay {
 216   unsigned offset;
 217
 218   switch (_weekDay) {
 219     case iCalWeekDaySunday:    offset = 0; break;
 220     case iCalWeekDayMonday:    offset = 1; break;
 221     case iCalWeekDayTuesday:   offset = 2; break;
 222     case iCalWeekDayWednesday: offset = 3; break;
 223     case iCalWeekDayThursday:  offset = 4; break;
 224     case iCalWeekDayFriday:    offset = 5; break;
 225     case iCalWeekDaySaturday:  offset = 6; break;
 226     default:                   offset = 0; break;
 227   }
 228   return offset;
 229 }
 230
 231 - (unsigned)offsetFromSundayForCurrentWeekStart {
 232   return [self offsetFromSundayForWeekDay:[self->rrule weekStart]];
 233 }
 234
 235 - (iCalWeekDay)weekDayForJulianNumber:(long)_jn {
 236   unsigned    day;
 237   iCalWeekDay weekDay;
 238
 239   day = [self offsetFromSundayForJulianNumber:_jn];
 240   switch (day) {
 241     case 0:  weekDay = iCalWeekDaySunday;    break;
 242     case 1:  weekDay = iCalWeekDayMonday;    break;
 243     case 2:  weekDay = iCalWeekDayTuesday;   break;
 244     case 3:  weekDay = iCalWeekDayWednesday; break;
 245     case 4:  weekDay = iCalWeekDayThursday;  break;
 246     case 5:  weekDay = iCalWeekDayFriday;    break;
 247     case 6:  weekDay = iCalWeekDaySaturday;  break;
 248     default: weekDay = iCalWeekDaySunday;    break; /* keep compiler happy */
 249   }
 250   return weekDay;
 251 }
 252
 253 /* calculation */
 254
 255 - (NSArray *)recurrenceRangesWithinCalendarDateRange:(NGCalendarDateRange *)_r {
 256   return nil; /* subclass responsibility */
 257 }
 258 - (BOOL)doesRecurrWithinCalendarDateRange:(NGCalendarDateRange *)_range {
 259   NSArray *ranges;
 260
 261   ranges = [self recurrenceRangesWithinCalendarDateRange:_range];
 262   return (ranges == nil || [ranges count] == 0) ? NO : YES;
 263 }
 264
 265 - (NGCalendarDateRange *)firstInstanceCalendarDateRange {
 266   return self->firstRange;
 267 }
 268
 269 - (NGCalendarDateRange *)lastInstanceCalendarDateRange {
 270   NSCalendarDate *start, *end;
 271
 272   start = [self lastInstanceStartDate];
 273   if (!start)
 274     return nil;
 275   end   = [start addTimeInterval:[self->firstRange duration]];
 276   return [NGCalendarDateRange calendarDateRangeWithStartDate:start
 277                               endDate:end];
 278 }
 279
 280 - (NSCalendarDate *)lastInstanceStartDate {
 281   NSCalendarDate *until;
 282
 283   /* NOTE: this is horribly inaccurate and doesn't even consider the use
 284   of repeatCount. It MUST be implemented by subclasses properly! However,
 285   it does the trick for SOGO 1.0 - that's why it's left here.
 286   */
 287   if ((until = [self->rrule untilDate]) != nil)
 288     return until;
 289   return nil;
 290 }
 291
 292 @end /* iCalRecurrenceCalculator */