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1 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
2 %% Name: datespan.tex
3 %% Purpose: wxDateSpan documentation
4 %% Author: Vadim Zeitlin
5 %% Modified by:
6 %% Created: 04.04.00
7 %% RCS-ID: $Id$
8 %% Copyright: (c) Vadim Zeitlin
9 %% License: wxWindows license
10 %%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
11
12 \section{\class{wxDateSpan}}\label{wxdatespan}
13
14 This class is a "logical time span" and is useful for implementing program
15 logic for such things as "add one month to the date" which, in general,
16 doesn't mean to add $60*60*24*31$ seconds to it, but to take the same date
17 the next month (to understand that this is indeed different consider adding
18 one month to Feb, 15 -- we want to get Mar, 15, of course).
19
20 When adding a month to the date, all lesser components (days, hours, ...)
21 won't be changed unless the resulting date would be invalid: for example,
22 Jan 31 + 1 month will be Feb 28, not (non-existing) Feb 31.
23
24 Because of this feature, adding and subtracting back again the same
25 wxDateSpan will {\bf not}, in general give back the original date: Feb 28 - 1
26 month will be Jan 28, not Jan 31!
27
28 wxDateSpan objects can be either positive or negative. They may be
29 multiplied by scalars which multiply all deltas by the scalar: i.e.
30 $2*(1 \hbox{ month and } 1 \hbox{ day})$ is $2$ months and $2$ days. They can
31 be added together and with \helpref{wxDateTime}{wxdatetime} or
32 \helpref{wxTimeSpan}{wxtimespan}, but the type of result is different for each
33 case.
34
35 Beware about weeks: if you specify both weeks and days, the total number of
36 days added will be $7*\hbox{weeks} + \hbox{days}$! See also GetTotalDays()
37 function.
38
39 Equality operators are defined for wxDateSpans. Two datespans are equal if
40 and only if they both give the same target date when added to {\bf every}\rtfsp
41 source date. Thus wxDateSpan::Months(1) is not equal to wxDateSpan::Days(30),
42 because they don't give the same date when added to 1 Feb. But
43 wxDateSpan::Days(14) is equal to wxDateSpan::Weeks(2)
44
45 Finally, notice that for adding hours, minutes and so on you don't need this
46 class at all: \helpref{wxTimeSpan}{wxtimespan} will do the job because there
47 are no subtleties associated with those (we don't support leap seconds).
48
49 \wxheading{Derived from}
50
51 No base class
52
53 \wxheading{Include files}
54
55 <wx/datetime.h>
56
57 \wxheading{Library}
58
59 \helpref{wxBase}{librarieslist}
60
61 \wxheading{See also}
62
63 \helpref{Date classes overview}{wxdatetimeoverview},\rtfsp
64 \helpref{wxDateTime}{wxdatetime}
65
66
67 \latexignore{\rtfignore{\wxheading{Members}}}
68
69 % wxDateSpan ctor
70 \membersection{wxDateSpan::wxDateSpan}\label{wxdatespanwxdatespan}
71
72 \func{}{wxDateSpan}{\param{int }{years = $0$}, \param{int }{months = $0$}, \param{int }{weeks = $0$}, \param{int }{days = $0$}}
73
74 Constructs the date span object for the given number of years, months, weeks
75 and days. Note that the weeks and days add together if both are given.
76
77 % wxDateSpan::Add
78 \membersection{wxDateSpan::Add}\label{wxdatespanadd}
79
80 \constfunc{wxDateSpan}{Add}{\param{const wxDateSpan\& }{other}}
81
82 \func{wxDateSpan\&}{Add}{\param{const wxDateSpan\& }{other}}
83
84 \func{wxDateSpan\&}{operator$+=$}{\param{const wxDateSpan\& }{other}}
85
86 Returns the sum of two date spans. The first version returns a new object, the
87 second and third ones modify this object in place.
88
89 % wxDateSpan::Day
90 \membersection{wxDateSpan::Day}\label{wxdatespanday}
91
92 \func{static wxDateSpan}{Day}{\void}
93
94 Returns a date span object corresponding to one day.
95
96 \wxheading{See also}
97
98 \helpref{Days}{wxdatespandays}
99
100 % wxDateSpan::Days
101 \membersection{wxDateSpan::Days}\label{wxdatespandays}
102
103 \func{static wxDateSpan}{Days}{\param{int }{days}}
104
105 Returns a date span object corresponding to the given number of days.
106
107 \wxheading{See also}
108
109 \helpref{Day}{wxdatespanday}
110
111 % wxDateSpan::GetDays
112 \membersection{wxDateSpan::GetDays}\label{wxdatespangetdays}
113
114 \constfunc{int}{GetDays}{\void}
115
116 Returns the number of days (only, that it not counting the weeks component!)
117 in this date span.
118
119 \wxheading{See also}
120
121 \helpref{GetTotalDays}{wxdatespangettotaldays}
122
123 % wxDateSpan::GetMonths
124 \membersection{wxDateSpan::GetMonths}\label{wxdatespangetmonths}
125
126 \constfunc{int}{GetMonths}{\void}
127
128 Returns the number of the months (not counting the years) in this date span.
129
130 % wxDateSpan::GetTotalDays
131 \membersection{wxDateSpan::GetTotalDays}\label{wxdatespangettotaldays}
132
133 \constfunc{int}{GetTotalDays}{\void}
134
135 Returns the combined number of days in this date span, counting both weeks and
136 days. It still doesn't take neither months nor years into the account.
137
138 \wxheading{See also}
139
140 \helpref{GetWeeks}{wxdatespangetweeks}, \helpref{GetDays}{wxdatespangetdays}
141
142 % wxDateSpan::GetWeeks
143 \membersection{wxDateSpan::GetWeeks}\label{wxdatespangetweeks}
144
145 \constfunc{int}{GetWeeks}{\void}
146
147 Returns the number of weeks in this date span.
148
149 \wxheading{See also}
150
151 \helpref{GetTotalDays}{wxdatespangettotaldays}
152
153 % wxDateSpan::GetYears
154 \membersection{wxDateSpan::GetYears}\label{wxdatespangetyears}
155
156 \constfunc{int}{GetYears}{\void}
157
158 Returns the number of years in this date span.
159
160 % wxDateSpan::Month
161 \membersection{wxDateSpan::Month}\label{wxdatespanmonth}
162
163 \func{static wxDateSpan}{Month}{\void}
164
165 Returns a date span object corresponding to one month.
166
167 \wxheading{See also}
168
169 \helpref{Months}{wxdatespanmonths}
170
171 % wxDateSpan::Months
172 \membersection{wxDateSpan::Months}\label{wxdatespanmonths}
173
174 \func{static wxDateSpan}{Months}{\param{int }{mon}}
175
176 Returns a date span object corresponding to the given number of months.
177
178 \wxheading{See also}
179
180 \helpref{Month}{wxdatespanmonth}
181
182 % wxDateSpan::Multiply
183 \membersection{wxDateSpan::Multiply}\label{wxdatespanmultiply}
184
185 \constfunc{wxDateSpan}{Multiply}{\param{int }{factor}}
186
187 \func{wxDateSpan\&}{Multiply}{\param{int }{factor}}
188
189 \func{wxDateSpan\&}{operator$*=$}{\param{int }{factor}}
190
191 Returns the product of the date span by the specified {\it factor}. The
192 product is computed by multiplying each of the components by the factor.
193
194 The first version returns a new object, the second and third ones modify this
195 object in place.
196
197 % wxDateSpan::Negate
198 \membersection{wxDateSpan::Negate}\label{wxdatespannegate}
199
200 \constfunc{wxDateSpan}{Negate}{\void}
201
202 Returns the date span with the opposite sign.
203
204 \wxheading{See also}
205
206 \helpref{Neg}{wxdatespanneg}
207
208 % wxDateSpan::Neg
209 \membersection{wxDateSpan::Neg}\label{wxdatespanneg}
210
211 \func{wxDateSpan\&}{Neg}{\void}
212
213 \func{wxDateSpan\&}{operator$-$}{\void}
214
215 Changes the sign of this date span.
216
217 \wxheading{See also}
218
219 \helpref{Negate}{wxdatespannegate}
220
221 % wxDateSpan::SetDays
222 \membersection{wxDateSpan::SetDays}\label{wxdatespansetdays}
223
224 \func{wxDateSpan\&}{SetDays}{\param{int }{n}}
225
226 Sets the number of days (without modifying any other components) in this date
227 span.
228
229 % wxDateSpan::SetYears
230 \membersection{wxDateSpan::SetYears}\label{wxdatespansetyears}
231
232 \func{wxDateSpan\&}{SetYears}{\param{int }{n}}
233
234 Sets the number of years (without modifying any other components) in this date
235 span.
236
237 % wxDateSpan::SetMonths
238 \membersection{wxDateSpan::SetMonths}\label{wxdatespansetmonths}
239
240 \func{wxDateSpan\&}{SetMonths}{\param{int }{n}}
241
242 Sets the number of months (without modifying any other components) in this
243 date span.
244
245 % wxDateSpan::SetWeeks
246 \membersection{wxDateSpan::SetWeeks}\label{wxdatespansetweeks}
247
248 \func{wxDateSpan\&}{SetWeeks}{\param{int }{n}}
249
250 Sets the number of weeks (without modifying any other components) in this date
251 span.
252
253 % wxDateSpan::Subtract
254 \membersection{wxDateSpan::Subtract}\label{wxdatespansubtract}
255
256 \constfunc{wxDateSpan}{Subtract}{\param{const wxDateSpan\& }{other}}
257
258 \func{wxDateSpan\&}{Subtract}{\param{const wxDateSpan\& }{other}}
259
260 \func{wxDateSpan\&}{operator$+=$}{\param{const wxDateSpan\& }{other}}
261
262 Returns the difference of two date spans. The first version returns a new
263 object, the second and third ones modify this object in place.
264
265 % wxDateSpan::Week
266 \membersection{wxDateSpan::Week}\label{wxdatespanweek}
267
268 \func{static wxDateSpan}{Week}{\void}
269
270 Returns a date span object corresponding to one week.
271
272 \wxheading{See also}
273
274 \helpref{Weeks}{wxdatespanweeks}
275
276 % wxDateSpan::Weeks
277 \membersection{wxDateSpan::Weeks}\label{wxdatespanweeks}
278
279 \func{static wxDateSpan}{Weeks}{\param{int }{weeks}}
280
281 Returns a date span object corresponding to the given number of weeks.
282
283 \wxheading{See also}
284
285 \helpref{Week}{wxdatespanweek}
286
287 % wxDateSpan::Year
288 \membersection{wxDateSpan::Year}\label{wxdatespanyear}
289
290 \func{static wxDateSpan}{Year}{\void}
291
292 Returns a date span object corresponding to one year.
293
294 \wxheading{See also}
295
296 \helpref{Years}{wxdatespanyears}
297
298 % wxDateSpan::Years
299 \membersection{wxDateSpan::Years}\label{wxdatespanyears}
300
301 \func{static wxDateSpan}{Years}{\param{int }{years}}
302
303 Returns a date span object corresponding to the given number of years.
304
305 \wxheading{See also}
306
307 \helpref{Year}{wxdatespanyear}
308
309 % wxDateSpan::operator==
310 \membersection{wxDateSpan::operator$==$}\label{wxdatespanoperatorequal}
311
312 \constfunc{bool}{operator$==$}{\param{wxDateSpan\&}{ other}}
313
314 Returns {\tt true} if this date span is equal to the other one. Two date spans
315 are considered equal if and only if they have the same number of years and
316 months and the same total number of days (counting both days and weeks).
317
318 % wxDateSpan::operator!=
319 \membersection{wxDateSpan::operator$!=$}\label{wxdatespanoperatornotequal}
320
321 \constfunc{bool}{operator$!=$}{\param{wxDateSpan\&}{ other}}
322
323 Returns {\tt true} if this date span is different from the other one.
324
325 \wxheading{See also}
326
327 \helpref{operator==}{wxdatespanoperatorequal}
328