1/*
2 This file is part of the kcalcore library.
3
4 Copyright (c) 2001-2003 Cornelius Schumacher <schumacher@kde.org>
5 Copyright (c) 2007 David Jarvie <djarvie@kde.org>
6
7 This library is free software; you can redistribute it and/or
8 modify it under the terms of the GNU Library General Public
9 License as published by the Free Software Foundation; either
10 version 2 of the License, or (at your option) any later version.
11
12 This library is distributed in the hope that it will be useful,
13 but WITHOUT ANY WARRANTY; without even the implied warranty of
14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 Library General Public License for more details.
16
17 You should have received a copy of the GNU Library General Public License
18 along with this library; see the file COPYING.LIB. If not, write to
19 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
20 Boston, MA 02110-1301, USA.
21*/
22/**
23 @file
24 This file is part of the API for handling calendar data and
25 defines the Duration class.
26
27 @author Cornelius Schumacher \<schumacher@kde.org\>
28 @author David Jarvie \<software@astrojar.org.uk\>
29*/
30
31#ifndef KCALCORE_DURATION_H
32#define KCALCORE_DURATION_H
33
34#include "kcalcore_export.h"
35
36#include <QDataStream>
37#include <QMetaType>
38
39class KDateTime;
40
41namespace KCalCore {
42
43/**
44 @brief
45 Represents a span of time measured in seconds or days.
46
47 A duration is a span of time measured in seconds or days. Construction can
48 be done by specifying a stop and end time, or simply by specifying the number
49 of seconds or days.
50
51 Much of the time, it does not matter whether a duration is specified in
52 seconds or in days. But it does make a difference when a duration is used to
53 define a time period encompassing a daylight saving time change.
54*/
55class KCALCORE_EXPORT Duration
56{
57public:
58 /**
59 The unit of time used to define the duration.
60 */
61 enum Type {
62 Seconds, /**< duration is a number of seconds */
63 Days /**< duration is a number of days */
64 };
65
66 /**
67 Constructs a duration of 0 seconds.
68 */
69 Duration();
70
71 /**
72 Constructs a duration from @p start to @p end.
73
74 If the time of day in @p start and @p end is equal, and their time
75 specifications (i.e. time zone etc.) are the same, the duration will be
76 set in terms of days. Otherwise, the duration will be set in terms of
77 seconds.
78
79 @param start is the time the duration begins.
80 @param end is the time the duration ends.
81 */
82 Duration(const KDateTime &start, const KDateTime &end);
83
84 /**
85 Constructs a duration from @p start to @p end.
86
87 If @p type is Days, and the time of day in @p start's time zone differs
88 between @p start and @p end, the duration will be rounded down to the
89 nearest whole number of days.
90
91 @param start is the time the duration begins.
92 @param end is the time the duration ends.
93 @param type the unit of time to use (seconds or days)
94 */
95 Duration(const KDateTime &start, const KDateTime &end, Type type);
96
97 /**
98 Constructs a duration with a number of seconds or days.
99
100 @param duration the number of seconds or days in the duration
101 @param type the unit of time to use (seconds or days)
102 */
103 // Keep the following implicit since instances are often used in integer evaluations.
104 Duration(int duration, Type type = Seconds); //krazy:exclude=explicit
105
106 /**
107 Constructs a duration by copying another duration object.
108
109 @param duration is the duration to copy.
110 */
111 Duration(const Duration &duration);
112
113 /**
114 Destroys a duration.
115 */
116 ~Duration();
117
118 /**
119 Sets this duration equal to @p duration.
120
121 @param duration is the duration to copy.
122 */
123 Duration &operator=(const Duration &duration);
124
125 /**
126 Returns true if this duration is non-zero.
127 */
128 operator bool() const;
129
130 /**
131 Returns true if this duration is zero.
132 */
133 bool operator!() const {
134 return !operator bool();
135 }
136
137 /**
138 Returns true if this duration is smaller than the @p other.
139 @param other is the other duration to compare.
140 */
141 bool operator<(const Duration &other) const;
142
143 /**
144 Returns true if this duration is smaller than or equal to the @p other.
145 @param other is the other duration to compare.
146 */
147 bool operator<=(const Duration &other) const
148 {
149 return !other.operator<(*this);
150 }
151
152 /**
153 Returns true if this duration is greater than the @p other.
154 @param other is the other duration to compare.
155 */
156 bool operator>(const Duration &other) const
157 {
158 return other.operator<(*this);
159 }
160
161 /**
162 Returns true if this duration is greater than or equal to the @p other.
163 @param other is the other duration to compare.
164 */
165 bool operator>=(const Duration &other) const
166 {
167 return !operator<(other);
168 }
169
170 /**
171 Returns true if this duration is equal to the @p other.
172 Daily and non-daily durations are always considered unequal, since a
173 day's duration may differ from 24 hours if it happens to span a daylight
174 saving time change.
175 @param other the other duration to compare
176 */
177 bool operator==(const Duration &other) const;
178
179 /**
180 Returns true if this duration is not equal to the @p other.
181 Daily and non-daily durations are always considered unequal, since a
182 day's duration may differ from 24 hours if it happens to span a daylight
183 saving time change.
184 @param other is the other duration to compare.
185 */
186 bool operator!=(const Duration &other) const
187 {
188 return !operator==(other);
189 }
190
191 /**
192 Adds another duration to this one.
193 If one is in terms of days and the other in terms of seconds,
194 the result is in terms of seconds.
195 @param other the other duration to add
196 */
197 Duration &operator+=(const Duration &other);
198
199 /**
200 Adds two durations.
201 If one is in terms of days and the other in terms of seconds,
202 the result is in terms of seconds.
203
204 @param other the other duration to add
205 @return combined duration
206 */
207 Duration operator+(const Duration &other) const
208 {
209 return Duration(*this) += other;
210 }
211
212 /**
213 Returns the negative of this duration.
214 */
215 Duration operator-() const;
216
217 /**
218 Subtracts another duration from this one.
219 If one is in terms of days and the other in terms of seconds,
220 the result is in terms of seconds.
221
222 @param other the other duration to subtract
223 */
224 Duration &operator-=(const Duration &other);
225
226 /**
227 Returns the difference between another duration and this.
228 If one is in terms of days and the other in terms of seconds,
229 the result is in terms of seconds.
230
231 @param other the other duration to subtract
232 @return difference in durations
233 */
234 Duration operator-(const Duration &other) const
235 {
236 return Duration(*this) += other;
237 }
238
239 /**
240 Multiplies this duration by a value.
241 @param value value to multiply by
242 */
243 Duration &operator*=(int value);
244
245 /**
246 Multiplies a duration by a value.
247
248 @param value value to multiply by
249 @return resultant duration
250 */
251 Duration operator*(int value) const
252 {
253 return Duration(*this) *= value;
254 }
255
256 /**
257 Divides this duration by a value.
258 @param value value to divide by
259 */
260 Duration &operator/=(int value);
261
262 /**
263 Divides a duration by a value.
264
265 @param value value to divide by
266 @return resultant duration
267 */
268 Duration operator/(int value) const
269 {
270 return Duration(*this) /= value;
271 }
272
273 /**
274 Computes a duration end time by adding the number of seconds or
275 days in the duration to the specified @p start time.
276
277 @param start is the start time.
278 @return end time.
279 */
280 KDateTime end(const KDateTime &start) const;
281
282 /**
283 Returns the time units (seconds or days) used to specify the duration.
284 */
285 Type type() const;
286
287 /**
288 Returns whether the duration is specified in terms of days rather
289 than seconds.
290 */
291 bool isDaily() const;
292
293 /**
294 Returns the length of the duration in seconds.
295 */
296 int asSeconds() const;
297
298 /**
299 Returns the length of the duration in days. If the duration is
300 not an exact number of days, it is rounded down to return the
301 number of whole days.
302 */
303 int asDays() const;
304
305 /**
306 Returns the length of the duration in seconds or days.
307
308 @return if isDaily(), duration in days, else duration in seconds
309 */
310 int value() const;
311
312private:
313 //@cond PRIVATE
314 class Private;
315 Private *const d;
316 //@endcond
317
318 friend KCALCORE_EXPORT QDataStream &operator<<(QDataStream &s, const KCalCore::Duration &);
319 friend KCALCORE_EXPORT QDataStream &operator>>(QDataStream &s, KCalCore::Duration &);
320};
321
322/**
323 * Duration serializer.
324 *
325 * @since 4.12
326 */
327KCALCORE_EXPORT QDataStream &operator<<(QDataStream &out, const KCalCore::Duration &);
328
329/**
330 * Duration deserializer.
331 *
332 * @since 4.12
333 */
334KCALCORE_EXPORT QDataStream &operator>>(QDataStream &in, KCalCore::Duration &);
335
336}
337
338Q_DECLARE_METATYPE(KCalCore::Duration)
339
340#endif
341