1 /*
2  ********************************************************************************
3  *   Copyright (C) 1997-2015, International Business Machines
4  *   Corporation and others.  All Rights Reserved.
5  ********************************************************************************
6  *
7  * File DATEFMT.H
8  *
9  * Modification History:
10  *
11  *   Date        Name        Description
12  *   02/19/97    aliu        Converted from java.
13  *   04/01/97    aliu        Added support for centuries.
14  *   07/23/98    stephen     JDK 1.2 sync
15  *   11/15/99    weiv        Added support for week of year/day of week formatting
16  ********************************************************************************
17  */
18 
19 #ifndef DATEFMT_H
20 #define DATEFMT_H
21 
22 #include "unicode/utypes.h"
23 
24 #if !UCONFIG_NO_FORMATTING
25 
26 #include "unicode/udat.h"
27 #include "unicode/calendar.h"
28 #include "unicode/numfmt.h"
29 #include "unicode/format.h"
30 #include "unicode/locid.h"
31 #include "unicode/enumset.h"
32 #include "unicode/udisplaycontext.h"
33 
34 /**
35  * \file
36  * \brief C++ API: Abstract class for converting dates.
37  */
38 
39 U_NAMESPACE_BEGIN
40 
41 class TimeZone;
42 class DateTimePatternGenerator;
43 
44 // explicit template instantiation. see digitlst.h
45 #if defined (_MSC_VER)
46 template class U_I18N_API EnumSet<UDateFormatBooleanAttribute,
47             0,
48             UDAT_BOOLEAN_ATTRIBUTE_COUNT>;
49 #endif
50 
51 /**
52  * DateFormat is an abstract class for a family of classes that convert dates and
53  * times from their internal representations to textual form and back again in a
54  * language-independent manner. Converting from the internal representation (milliseconds
55  * since midnight, January 1, 1970) to text is known as "formatting," and converting
56  * from text to millis is known as "parsing."  We currently define only one concrete
57  * subclass of DateFormat: SimpleDateFormat, which can handle pretty much all normal
58  * date formatting and parsing actions.
59  * <P>
60  * DateFormat helps you to format and parse dates for any locale. Your code can
61  * be completely independent of the locale conventions for months, days of the
62  * week, or even the calendar format: lunar vs. solar.
63  * <P>
64  * To format a date for the current Locale, use one of the static factory
65  * methods:
66  * <pre>
67  * \code
68  *      DateFormat* dfmt = DateFormat::createDateInstance();
69  *      UDate myDate = Calendar::getNow();
70  *      UnicodeString myString;
71  *      myString = dfmt->format( myDate, myString );
72  * \endcode
73  * </pre>
74  * If you are formatting multiple numbers, it is more efficient to get the
75  * format and use it multiple times so that the system doesn't have to fetch the
76  * information about the local language and country conventions multiple times.
77  * <pre>
78  * \code
79  *      DateFormat* df = DateFormat::createDateInstance();
80  *      UnicodeString myString;
81  *      UDate myDateArr[] = { 0.0, 100000000.0, 2000000000.0 }; // test values
82  *      for (int32_t i = 0; i < 3; ++i) {
83  *          myString.remove();
84  *          cout << df->format( myDateArr[i], myString ) << endl;
85  *      }
86  * \endcode
87  * </pre>
88  * To get specific fields of a date, you can use UFieldPosition to
89  * get specific fields.
90  * <pre>
91  * \code
92  *      DateFormat* dfmt = DateFormat::createDateInstance();
93  *      FieldPosition pos(DateFormat::YEAR_FIELD);
94  *      UnicodeString myString;
95  *      myString = dfmt->format( myDate, myString );
96  *      cout << myString << endl;
97  *      cout << pos.getBeginIndex() << "," << pos. getEndIndex() << endl;
98  * \endcode
99  * </pre>
100  * To format a date for a different Locale, specify it in the call to
101  * createDateInstance().
102  * <pre>
103  * \code
104  *       DateFormat* df =
105  *           DateFormat::createDateInstance( DateFormat::SHORT, Locale::getFrance());
106  * \endcode
107  * </pre>
108  * You can use a DateFormat to parse also.
109  * <pre>
110  * \code
111  *       UErrorCode status = U_ZERO_ERROR;
112  *       UDate myDate = df->parse(myString, status);
113  * \endcode
114  * </pre>
115  * Use createDateInstance() to produce the normal date format for that country.
116  * There are other static factory methods available. Use createTimeInstance()
117  * to produce the normal time format for that country. Use createDateTimeInstance()
118  * to produce a DateFormat that formats both date and time. You can pass in
119  * different options to these factory methods to control the length of the
120  * result; from SHORT to MEDIUM to LONG to FULL. The exact result depends on the
121  * locale, but generally:
122  * <ul type=round>
123  *   <li>   SHORT is completely numeric, such as 12/13/52 or 3:30pm
124  *   <li>   MEDIUM is longer, such as Jan 12, 1952
125  *   <li>   LONG is longer, such as January 12, 1952 or 3:30:32pm
126  *   <li>   FULL is pretty completely specified, such as
127  *          Tuesday, April 12, 1952 AD or 3:30:42pm PST.
128  * </ul>
129  * You can also set the time zone on the format if you wish. If you want even
130  * more control over the format or parsing, (or want to give your users more
131  * control), you can try casting the DateFormat you get from the factory methods
132  * to a SimpleDateFormat. This will work for the majority of countries; just
133  * remember to chck getDynamicClassID() before carrying out the cast.
134  * <P>
135  * You can also use forms of the parse and format methods with ParsePosition and
136  * FieldPosition to allow you to
137  * <ul type=round>
138  *   <li>   Progressively parse through pieces of a string.
139  *   <li>   Align any particular field, or find out where it is for selection
140  *          on the screen.
141  * </ul>
142  *
143  * <p><em>User subclasses are not supported.</em> While clients may write
144  * subclasses, such code will not necessarily work and will not be
145  * guaranteed to work stably from release to release.
146  */
147 class U_I18N_API DateFormat : public Format {
148 public:
149 
150     /**
151      * Constants for various style patterns. These reflect the order of items in
152      * the DateTimePatterns resource. There are 4 time patterns, 4 date patterns,
153      * the default date-time pattern, and 4 date-time patterns. Each block of 4 values
154      * in the resource occurs in the order full, long, medium, short.
155      * @stable ICU 2.4
156      */
157     enum EStyle
158     {
159         kNone   = -1,
160 
161         kFull   = 0,
162         kLong   = 1,
163         kMedium = 2,
164         kShort  = 3,
165 
166         kDateOffset   = kShort + 1,
167      // kFull   + kDateOffset = 4
168      // kLong   + kDateOffset = 5
169      // kMedium + kDateOffset = 6
170      // kShort  + kDateOffset = 7
171 
172         kDateTime             = 8,
173      // Default DateTime
174 
175         kDateTimeOffset = kDateTime + 1,
176      // kFull   + kDateTimeOffset = 9
177      // kLong   + kDateTimeOffset = 10
178      // kMedium + kDateTimeOffset = 11
179      // kShort  + kDateTimeOffset = 12
180 
181         // relative dates
182         kRelative = (1 << 7),
183 
184         kFullRelative = (kFull | kRelative),
185 
186         kLongRelative = kLong | kRelative,
187 
188         kMediumRelative = kMedium | kRelative,
189 
190         kShortRelative = kShort | kRelative,
191 
192 
193         kDefault      = kMedium,
194 
195 
196 
197     /**
198      * These constants are provided for backwards compatibility only.
199      * Please use the C++ style constants defined above.
200      */
201         FULL        = kFull,
202         LONG        = kLong,
203         MEDIUM        = kMedium,
204         SHORT        = kShort,
205         DEFAULT        = kDefault,
206         DATE_OFFSET    = kDateOffset,
207         NONE        = kNone,
208         DATE_TIME    = kDateTime
209     };
210 
211     /**
212      * Destructor.
213      * @stable ICU 2.0
214      */
215     virtual ~DateFormat();
216 
217     /**
218      * Equality operator.  Returns true if the two formats have the same behavior.
219      * @stable ICU 2.0
220      */
221     virtual UBool operator==(const Format&) const;
222 
223 
224     using Format::format;
225 
226     /**
227      * Format an object to produce a string. This method handles Formattable
228      * objects with a UDate type. If a the Formattable object type is not a Date,
229      * then it returns a failing UErrorCode.
230      *
231      * @param obj       The object to format. Must be a Date.
232      * @param appendTo  Output parameter to receive result.
233      *                  Result is appended to existing contents.
234      * @param pos       On input: an alignment field, if desired.
235      *                  On output: the offsets of the alignment field.
236      * @param status    Output param filled with success/failure status.
237      * @return          Reference to 'appendTo' parameter.
238      * @stable ICU 2.0
239      */
240     virtual UnicodeString& format(const Formattable& obj,
241                                   UnicodeString& appendTo,
242                                   FieldPosition& pos,
243                                   UErrorCode& status) const;
244 
245     /**
246      * Format an object to produce a string. This method handles Formattable
247      * objects with a UDate type. If a the Formattable object type is not a Date,
248      * then it returns a failing UErrorCode.
249      *
250      * @param obj       The object to format. Must be a Date.
251      * @param appendTo  Output parameter to receive result.
252      *                  Result is appended to existing contents.
253      * @param posIter   On return, can be used to iterate over positions
254      *                  of fields generated by this format call.  Field values
255      *                  are defined in UDateFormatField.  Can be NULL.
256      * @param status    Output param filled with success/failure status.
257      * @return          Reference to 'appendTo' parameter.
258      * @stable ICU 4.4
259      */
260     virtual UnicodeString& format(const Formattable& obj,
261                                   UnicodeString& appendTo,
262                                   FieldPositionIterator* posIter,
263                                   UErrorCode& status) const;
264     /**
265      * Formats a date into a date/time string. This is an abstract method which
266      * concrete subclasses must implement.
267      * <P>
268      * On input, the FieldPosition parameter may have its "field" member filled with
269      * an enum value specifying a field.  On output, the FieldPosition will be filled
270      * in with the text offsets for that field.
271      * <P> For example, given a time text
272      * "1996.07.10 AD at 15:08:56 PDT", if the given fieldPosition.field is
273      * UDAT_YEAR_FIELD, the offsets fieldPosition.beginIndex and
274      * statfieldPositionus.getEndIndex will be set to 0 and 4, respectively.
275      * <P> Notice
276      * that if the same time field appears more than once in a pattern, the status will
277      * be set for the first occurence of that time field. For instance,
278      * formatting a UDate to the time string "1 PM PDT (Pacific Daylight Time)"
279      * using the pattern "h a z (zzzz)" and the alignment field
280      * DateFormat::TIMEZONE_FIELD, the offsets fieldPosition.beginIndex and
281      * fieldPosition.getEndIndex will be set to 5 and 8, respectively, for the first
282      * occurence of the timezone pattern character 'z'.
283      *
284      * @param cal           Calendar set to the date and time to be formatted
285      *                      into a date/time string.  When the calendar type is
286      *                      different from the internal calendar held by this
287      *                      DateFormat instance, the date and the time zone will
288      *                      be inherited from the input calendar, but other calendar
289      *                      field values will be calculated by the internal calendar.
290      * @param appendTo      Output parameter to receive result.
291      *                      Result is appended to existing contents.
292      * @param fieldPosition On input: an alignment field, if desired (see examples above)
293      *                      On output: the offsets of the alignment field (see examples above)
294      * @return              Reference to 'appendTo' parameter.
295      * @stable ICU 2.1
296      */
297     virtual UnicodeString& format(  Calendar& cal,
298                                     UnicodeString& appendTo,
299                                     FieldPosition& fieldPosition) const = 0;
300 
301     /**
302      * Formats a date into a date/time string. Subclasses should implement this method.
303      *
304      * @param cal       Calendar set to the date and time to be formatted
305      *                  into a date/time string.  When the calendar type is
306      *                  different from the internal calendar held by this
307      *                  DateFormat instance, the date and the time zone will
308      *                  be inherited from the input calendar, but other calendar
309      *                  field values will be calculated by the internal calendar.
310      * @param appendTo  Output parameter to receive result.
311      *                  Result is appended to existing contents.
312      * @param posIter   On return, can be used to iterate over positions
313      *                  of fields generated by this format call.  Field values
314      *                  are defined in UDateFormatField.  Can be NULL.
315      * @param status    error status.
316      * @return          Reference to 'appendTo' parameter.
317      * @stable ICU 4.4
318      */
319     virtual UnicodeString& format(Calendar& cal,
320                                   UnicodeString& appendTo,
321                                   FieldPositionIterator* posIter,
322                                   UErrorCode& status) const;
323     /**
324      * Formats a UDate into a date/time string.
325      * <P>
326      * On input, the FieldPosition parameter may have its "field" member filled with
327      * an enum value specifying a field.  On output, the FieldPosition will be filled
328      * in with the text offsets for that field.
329      * <P> For example, given a time text
330      * "1996.07.10 AD at 15:08:56 PDT", if the given fieldPosition.field is
331      * UDAT_YEAR_FIELD, the offsets fieldPosition.beginIndex and
332      * statfieldPositionus.getEndIndex will be set to 0 and 4, respectively.
333      * <P> Notice
334      * that if the same time field appears more than once in a pattern, the status will
335      * be set for the first occurence of that time field. For instance,
336      * formatting a UDate to the time string "1 PM PDT (Pacific Daylight Time)"
337      * using the pattern "h a z (zzzz)" and the alignment field
338      * DateFormat::TIMEZONE_FIELD, the offsets fieldPosition.beginIndex and
339      * fieldPosition.getEndIndex will be set to 5 and 8, respectively, for the first
340      * occurence of the timezone pattern character 'z'.
341      *
342      * @param date          UDate to be formatted into a date/time string.
343      * @param appendTo      Output parameter to receive result.
344      *                      Result is appended to existing contents.
345      * @param fieldPosition On input: an alignment field, if desired (see examples above)
346      *                      On output: the offsets of the alignment field (see examples above)
347      * @return              Reference to 'appendTo' parameter.
348      * @stable ICU 2.0
349      */
350     UnicodeString& format(  UDate date,
351                             UnicodeString& appendTo,
352                             FieldPosition& fieldPosition) const;
353 
354     /**
355      * Formats a UDate into a date/time string.
356      *
357      * @param date      UDate to be formatted into a date/time string.
358      * @param appendTo  Output parameter to receive result.
359      *                  Result is appended to existing contents.
360      * @param posIter   On return, can be used to iterate over positions
361      *                  of fields generated by this format call.  Field values
362      *                  are defined in UDateFormatField.  Can be NULL.
363      * @param status    error status.
364      * @return          Reference to 'appendTo' parameter.
365      * @stable ICU 4.4
366      */
367     UnicodeString& format(UDate date,
368                           UnicodeString& appendTo,
369                           FieldPositionIterator* posIter,
370                           UErrorCode& status) const;
371     /**
372      * Formats a UDate into a date/time string. If there is a problem, you won't
373      * know, using this method. Use the overloaded format() method which takes a
374      * FieldPosition& to detect formatting problems.
375      *
376      * @param date      The UDate value to be formatted into a string.
377      * @param appendTo  Output parameter to receive result.
378      *                  Result is appended to existing contents.
379      * @return          Reference to 'appendTo' parameter.
380      * @stable ICU 2.0
381      */
382     UnicodeString& format(UDate date, UnicodeString& appendTo) const;
383 
384     /**
385      * Parse a date/time string. For example, a time text "07/10/96 4:5 PM, PDT"
386      * will be parsed into a UDate that is equivalent to Date(837039928046).
387      * Parsing begins at the beginning of the string and proceeds as far as
388      * possible.  Assuming no parse errors were encountered, this function
389      * doesn't return any information about how much of the string was consumed
390      * by the parsing.  If you need that information, use the version of
391      * parse() that takes a ParsePosition.
392      * <P>
393      * By default, parsing is lenient: If the input is not in the form used by
394      * this object's format method but can still be parsed as a date, then the
395      * parse succeeds. Clients may insist on strict adherence to the format by
396      * calling setLenient(false).
397      * @see DateFormat::setLenient(boolean)
398      * <P>
399      * Note that the normal date formats associated with some calendars - such
400      * as the Chinese lunar calendar - do not specify enough fields to enable
401      * dates to be parsed unambiguously. In the case of the Chinese lunar
402      * calendar, while the year within the current 60-year cycle is specified,
403      * the number of such cycles since the start date of the calendar (in the
404      * ERA field of the Calendar object) is not normally part of the format,
405      * and parsing may assume the wrong era. For cases such as this it is
406      * recommended that clients parse using the method
407      * parse(const UnicodeString&, Calendar& cal, ParsePosition&)
408      * with the Calendar passed in set to the current date, or to a date
409      * within the era/cycle that should be assumed if absent in the format.
410      *
411      * @param text      The date/time string to be parsed into a UDate value.
412      * @param status    Output param to be set to success/failure code. If
413      *                  'text' cannot be parsed, it will be set to a failure
414      *                  code.
415      * @return          The parsed UDate value, if successful.
416      * @stable ICU 2.0
417      */
418     virtual UDate parse( const UnicodeString& text,
419                         UErrorCode& status) const;
420 
421     /**
422      * Parse a date/time string beginning at the given parse position. For
423      * example, a time text "07/10/96 4:5 PM, PDT" will be parsed into a Date
424      * that is equivalent to Date(837039928046).
425      * <P>
426      * By default, parsing is lenient: If the input is not in the form used by
427      * this object's format method but can still be parsed as a date, then the
428      * parse succeeds. Clients may insist on strict adherence to the format by
429      * calling setLenient(false).
430      * @see DateFormat::setLenient(boolean)
431      *
432      * @param text  The date/time string to be parsed.
433      * @param cal   A Calendar set on input to the date and time to be used for
434      *              missing values in the date/time string being parsed, and set
435      *              on output to the parsed date/time. When the calendar type is
436      *              different from the internal calendar held by this DateFormat
437      *              instance, the internal calendar will be cloned to a work
438      *              calendar set to the same milliseconds and time zone as the
439      *              cal parameter, field values will be parsed based on the work
440      *              calendar, then the result (milliseconds and time zone) will
441      *              be set in this calendar.
442      * @param pos   On input, the position at which to start parsing; on
443      *              output, the position at which parsing terminated, or the
444      *              start position if the parse failed.
445      * @stable ICU 2.1
446      */
447     virtual void parse( const UnicodeString& text,
448                         Calendar& cal,
449                         ParsePosition& pos) const = 0;
450 
451     /**
452      * Parse a date/time string beginning at the given parse position. For
453      * example, a time text "07/10/96 4:5 PM, PDT" will be parsed into a Date
454      * that is equivalent to Date(837039928046).
455      * <P>
456      * By default, parsing is lenient: If the input is not in the form used by
457      * this object's format method but can still be parsed as a date, then the
458      * parse succeeds. Clients may insist on strict adherence to the format by
459      * calling setLenient(false).
460      * @see DateFormat::setLenient(boolean)
461      * <P>
462      * Note that the normal date formats associated with some calendars - such
463      * as the Chinese lunar calendar - do not specify enough fields to enable
464      * dates to be parsed unambiguously. In the case of the Chinese lunar
465      * calendar, while the year within the current 60-year cycle is specified,
466      * the number of such cycles since the start date of the calendar (in the
467      * ERA field of the Calendar object) is not normally part of the format,
468      * and parsing may assume the wrong era. For cases such as this it is
469      * recommended that clients parse using the method
470      * parse(const UnicodeString&, Calendar& cal, ParsePosition&)
471      * with the Calendar passed in set to the current date, or to a date
472      * within the era/cycle that should be assumed if absent in the format.
473      *
474      * @param text  The date/time string to be parsed into a UDate value.
475      * @param pos   On input, the position at which to start parsing; on
476      *              output, the position at which parsing terminated, or the
477      *              start position if the parse failed.
478      * @return      A valid UDate if the input could be parsed.
479      * @stable ICU 2.0
480      */
481     UDate parse( const UnicodeString& text,
482                  ParsePosition& pos) const;
483 
484     /**
485      * Parse a string to produce an object. This methods handles parsing of
486      * date/time strings into Formattable objects with UDate types.
487      * <P>
488      * Before calling, set parse_pos.index to the offset you want to start
489      * parsing at in the source. After calling, parse_pos.index is the end of
490      * the text you parsed. If error occurs, index is unchanged.
491      * <P>
492      * When parsing, leading whitespace is discarded (with a successful parse),
493      * while trailing whitespace is left as is.
494      * <P>
495      * See Format::parseObject() for more.
496      *
497      * @param source    The string to be parsed into an object.
498      * @param result    Formattable to be set to the parse result.
499      *                  If parse fails, return contents are undefined.
500      * @param parse_pos The position to start parsing at. Upon return
501      *                  this param is set to the position after the
502      *                  last character successfully parsed. If the
503      *                  source is not parsed successfully, this param
504      *                  will remain unchanged.
505      * @stable ICU 2.0
506      */
507     virtual void parseObject(const UnicodeString& source,
508                              Formattable& result,
509                              ParsePosition& parse_pos) const;
510 
511     /**
512      * Create a default date/time formatter that uses the SHORT style for both
513      * the date and the time.
514      *
515      * @return A date/time formatter which the caller owns.
516      * @stable ICU 2.0
517      */
518     static DateFormat* U_EXPORT2 createInstance(void);
519 
520     /**
521      * Creates a time formatter with the given formatting style for the given
522      * locale.
523      *
524      * @param style     The given formatting style. For example,
525      *                  SHORT for "h:mm a" in the US locale. Relative
526      *                  time styles are not currently supported.
527      * @param aLocale   The given locale.
528      * @return          A time formatter which the caller owns.
529      * @stable ICU 2.0
530      */
531     static DateFormat* U_EXPORT2 createTimeInstance(EStyle style = kDefault,
532                                           const Locale& aLocale = Locale::getDefault());
533 
534     /**
535      * Creates a date formatter with the given formatting style for the given
536      * const locale.
537      *
538      * @param style     The given formatting style. For example, SHORT for "M/d/yy" in the
539      *                  US locale. As currently implemented, relative date formatting only
540      *                  affects a limited range of calendar days before or after the
541      *                  current date, based on the CLDR &lt;field type="day"&gt;/&lt;relative&gt; data:
542      *                  For example, in English, "Yesterday", "Today", and "Tomorrow".
543      *                  Outside of this range, dates are formatted using the corresponding
544      *                  non-relative style.
545      * @param aLocale   The given locale.
546      * @return          A date formatter which the caller owns.
547      * @stable ICU 2.0
548      */
549     static DateFormat* U_EXPORT2 createDateInstance(EStyle style = kDefault,
550                                           const Locale& aLocale = Locale::getDefault());
551 
552     /**
553      * Creates a date/time formatter with the given formatting styles for the
554      * given locale.
555      *
556      * @param dateStyle The given formatting style for the date portion of the result.
557      *                  For example, SHORT for "M/d/yy" in the US locale. As currently
558      *                  implemented, relative date formatting only affects a limited range
559      *                  of calendar days before or after the current date, based on the
560      *                  CLDR &lt;field type="day"&gt;/&lt;relative&gt; data: For example, in English,
561      *                  "Yesterday", "Today", and "Tomorrow". Outside of this range, dates
562      *                  are formatted using the corresponding non-relative style.
563      * @param timeStyle The given formatting style for the time portion of the result.
564      *                  For example, SHORT for "h:mm a" in the US locale. Relative
565      *                  time styles are not currently supported.
566      * @param aLocale   The given locale.
567      * @return          A date/time formatter which the caller owns.
568      * @stable ICU 2.0
569      */
570     static DateFormat* U_EXPORT2 createDateTimeInstance(EStyle dateStyle = kDefault,
571                                               EStyle timeStyle = kDefault,
572                                               const Locale& aLocale = Locale::getDefault());
573 
574 #ifndef U_HIDE_INTERNAL_API
575     /**
576      * Returns the best pattern given a skeleton and locale.
577      * @param locale the locale
578      * @param skeleton the skeleton
579      * @param status ICU error returned here
580      * @return the best pattern.
581      * @internal For ICU use only.
582      */
583     static UnicodeString getBestPattern(
584             const Locale &locale,
585             const UnicodeString &skeleton,
586             UErrorCode &status);
587 #endif  /* U_HIDE_INTERNAL_API */
588 
589 #ifndef U_HIDE_DRAFT_API
590     /**
591      * Creates a date/time formatter for the given skeleton and
592      * default locale.
593      *
594      * @param skeleton The skeleton e.g "yMMMMd." Fields in the skeleton can
595      *                 be in any order, and this method uses the locale to
596      *                 map the skeleton to a pattern that includes locale
597      *                 specific separators with the fields in the appropriate
598      *                 order for that locale.
599      * @param status   Any error returned here.
600      * @return         A date/time formatter which the caller owns.
601      * @draft ICU 55
602      */
603     static DateFormat* U_EXPORT2 createInstanceForSkeleton(
604             const UnicodeString& skeleton,
605             UErrorCode &status);
606 
607     /**
608      * Creates a date/time formatter for the given skeleton and locale.
609      *
610      * @param skeleton The skeleton e.g "yMMMMd." Fields in the skeleton can
611      *                 be in any order, and this method uses the locale to
612      *                 map the skeleton to a pattern that includes locale
613      *                 specific separators with the fields in the appropriate
614      *                 order for that locale.
615      * @param locale  The given locale.
616      * @param status   Any error returned here.
617      * @return         A date/time formatter which the caller owns.
618      * @draft ICU 55
619      */
620     static DateFormat* U_EXPORT2 createInstanceForSkeleton(
621             const UnicodeString& skeleton,
622             const Locale &locale,
623             UErrorCode &status);
624 
625     /**
626      * Creates a date/time formatter for the given skeleton and locale.
627      *
628      * @param calendarToAdopt the calendar returned DateFormat is to use.
629      * @param skeleton The skeleton e.g "yMMMMd." Fields in the skeleton can
630      *                 be in any order, and this method uses the locale to
631      *                 map the skeleton to a pattern that includes locale
632      *                 specific separators with the fields in the appropriate
633      *                 order for that locale.
634      * @param locale  The given locale.
635      * @param status   Any error returned here.
636      * @return         A date/time formatter which the caller owns.
637      * @draft ICU 55
638      */
639     static DateFormat* U_EXPORT2 createInstanceForSkeleton(
640             Calendar *calendarToAdopt,
641             const UnicodeString& skeleton,
642             const Locale &locale,
643             UErrorCode &status);
644 
645 #endif /* U_HIDE_DRAFT_API */
646 
647     /**
648      * Gets the set of locales for which DateFormats are installed.
649      * @param count Filled in with the number of locales in the list that is returned.
650      * @return the set of locales for which DateFormats are installed.  The caller
651      *  does NOT own this list and must not delete it.
652      * @stable ICU 2.0
653      */
654     static const Locale* U_EXPORT2 getAvailableLocales(int32_t& count);
655 
656     /**
657      * Returns whether both date/time parsing in the encapsulated Calendar object and DateFormat whitespace &
658      * numeric processing is lenient.
659      * @stable ICU 2.0
660      */
661     virtual UBool isLenient(void) const;
662 
663     /**
664      * Specifies whether date/time parsing is to be lenient.  With
665      * lenient parsing, the parser may use heuristics to interpret inputs that
666      * do not precisely match this object's format.  Without lenient parsing,
667      * inputs must match this object's format more closely.
668      *
669      * Note: ICU 53 introduced finer grained control of leniency (and added
670      * new control points) making the preferred method a combination of
671      * setCalendarLenient() & setBooleanAttribute() calls.
672      * This method supports prior functionality but may not support all
673      * future leniency control & behavior of DateFormat. For control of pre 53 leniency,
674      * Calendar and DateFormat whitespace & numeric tolerance, this method is safe to
675      * use. However, mixing leniency control via this method and modification of the
676      * newer attributes via setBooleanAttribute() may produce undesirable
677      * results.
678      *
679      * @param lenient  True specifies date/time interpretation to be lenient.
680      * @see Calendar::setLenient
681      * @stable ICU 2.0
682      */
683     virtual void setLenient(UBool lenient);
684 
685 
686     /**
687      * Returns whether date/time parsing in the encapsulated Calendar object processing is lenient.
688      * @stable ICU 53
689      */
690     virtual UBool isCalendarLenient(void) const;
691 
692 
693     /**
694      * Specifies whether encapsulated Calendar date/time parsing is to be lenient.  With
695      * lenient parsing, the parser may use heuristics to interpret inputs that
696      * do not precisely match this object's format.  Without lenient parsing,
697      * inputs must match this object's format more closely.
698      * @param lenient when true, parsing is lenient
699      * @see com.ibm.icu.util.Calendar#setLenient
700      * @stable ICU 53
701      */
702     virtual void setCalendarLenient(UBool lenient);
703 
704 
705     /**
706      * Gets the calendar associated with this date/time formatter.
707      * The calendar is owned by the formatter and must not be modified.
708      * Also, the calendar does not reflect the results of a parse operation.
709      * To parse to a calendar, use {@link #parse(const UnicodeString&, Calendar& cal, ParsePosition&) const parse(const UnicodeString&, Calendar& cal, ParsePosition&)}
710      * @return the calendar associated with this date/time formatter.
711      * @stable ICU 2.0
712      */
713     virtual const Calendar* getCalendar(void) const;
714 
715     /**
716      * Set the calendar to be used by this date format. Initially, the default
717      * calendar for the specified or default locale is used.  The caller should
718      * not delete the Calendar object after it is adopted by this call.
719      * Adopting a new calendar will change to the default symbols.
720      *
721      * @param calendarToAdopt    Calendar object to be adopted.
722      * @stable ICU 2.0
723      */
724     virtual void adoptCalendar(Calendar* calendarToAdopt);
725 
726     /**
727      * Set the calendar to be used by this date format. Initially, the default
728      * calendar for the specified or default locale is used.
729      *
730      * @param newCalendar Calendar object to be set.
731      * @stable ICU 2.0
732      */
733     virtual void setCalendar(const Calendar& newCalendar);
734 
735 
736     /**
737      * Gets the number formatter which this date/time formatter uses to format
738      * and parse the numeric portions of the pattern.
739      * @return the number formatter which this date/time formatter uses.
740      * @stable ICU 2.0
741      */
742     virtual const NumberFormat* getNumberFormat(void) const;
743 
744     /**
745      * Allows you to set the number formatter.  The caller should
746      * not delete the NumberFormat object after it is adopted by this call.
747      * @param formatToAdopt     NumberFormat object to be adopted.
748      * @stable ICU 2.0
749      */
750     virtual void adoptNumberFormat(NumberFormat* formatToAdopt);
751 
752     /**
753      * Allows you to set the number formatter.
754      * @param newNumberFormat  NumberFormat object to be set.
755      * @stable ICU 2.0
756      */
757     virtual void setNumberFormat(const NumberFormat& newNumberFormat);
758 
759     /**
760      * Returns a reference to the TimeZone used by this DateFormat's calendar.
761      * @return the time zone associated with the calendar of DateFormat.
762      * @stable ICU 2.0
763      */
764     virtual const TimeZone& getTimeZone(void) const;
765 
766     /**
767      * Sets the time zone for the calendar of this DateFormat object. The caller
768      * no longer owns the TimeZone object and should not delete it after this call.
769      * @param zoneToAdopt the TimeZone to be adopted.
770      * @stable ICU 2.0
771      */
772     virtual void adoptTimeZone(TimeZone* zoneToAdopt);
773 
774     /**
775      * Sets the time zone for the calendar of this DateFormat object.
776      * @param zone the new time zone.
777      * @stable ICU 2.0
778      */
779     virtual void setTimeZone(const TimeZone& zone);
780 
781     /**
782      * Set a particular UDisplayContext value in the formatter, such as
783      * UDISPCTX_CAPITALIZATION_FOR_STANDALONE.
784      * @param value The UDisplayContext value to set.
785      * @param status Input/output status. If at entry this indicates a failure
786      *               status, the function will do nothing; otherwise this will be
787      *               updated with any new status from the function.
788      * @stable ICU 53
789      */
790     virtual void setContext(UDisplayContext value, UErrorCode& status);
791 
792     /**
793      * Get the formatter's UDisplayContext value for the specified UDisplayContextType,
794      * such as UDISPCTX_TYPE_CAPITALIZATION.
795      * @param type The UDisplayContextType whose value to return
796      * @param status Input/output status. If at entry this indicates a failure
797      *               status, the function will do nothing; otherwise this will be
798      *               updated with any new status from the function.
799      * @return The UDisplayContextValue for the specified type.
800      * @stable ICU 53
801      */
802     virtual UDisplayContext getContext(UDisplayContextType type, UErrorCode& status) const;
803 
804    /**
805      * Sets an boolean attribute on this DateFormat.
806      * May return U_UNSUPPORTED_ERROR if this instance does not support
807      * the specified attribute.
808      * @param attr the attribute to set
809      * @param newvalue new value
810      * @param status the error type
811      * @return *this - for chaining (example: format.setAttribute(...).setAttribute(...) )
812      * @stable ICU 53
813      */
814 
815     virtual DateFormat&  U_EXPORT2 setBooleanAttribute(UDateFormatBooleanAttribute attr,
816     									UBool newvalue,
817     									UErrorCode &status);
818 
819     /**
820      * Returns a boolean from this DateFormat
821      * May return U_UNSUPPORTED_ERROR if this instance does not support
822      * the specified attribute.
823      * @param attr the attribute to set
824      * @param status the error type
825      * @return the attribute value. Undefined if there is an error.
826      * @stable ICU 53
827      */
828     virtual UBool U_EXPORT2 getBooleanAttribute(UDateFormatBooleanAttribute attr, UErrorCode &status) const;
829 
830 protected:
831     /**
832      * Default constructor.  Creates a DateFormat with no Calendar or NumberFormat
833      * associated with it.  This constructor depends on the subclasses to fill in
834      * the calendar and numberFormat fields.
835      * @stable ICU 2.0
836      */
837     DateFormat();
838 
839     /**
840      * Copy constructor.
841      * @stable ICU 2.0
842      */
843     DateFormat(const DateFormat&);
844 
845     /**
846      * Default assignment operator.
847      * @stable ICU 2.0
848      */
849     DateFormat& operator=(const DateFormat&);
850 
851     /**
852      * The calendar that DateFormat uses to produce the time field values needed
853      * to implement date/time formatting. Subclasses should generally initialize
854      * this to the default calendar for the locale associated with this DateFormat.
855      * @stable ICU 2.4
856      */
857     Calendar* fCalendar;
858 
859     /**
860      * The number formatter that DateFormat uses to format numbers in dates and
861      * times. Subclasses should generally initialize this to the default number
862      * format for the locale associated with this DateFormat.
863      * @stable ICU 2.4
864      */
865     NumberFormat* fNumberFormat;
866 
867 
868 private:
869 
870     /**
871      * Gets the date/time formatter with the given formatting styles for the
872      * given locale.
873      * @param dateStyle the given date formatting style.
874      * @param timeStyle the given time formatting style.
875      * @param inLocale the given locale.
876      * @return a date/time formatter, or 0 on failure.
877      */
878     static DateFormat* U_EXPORT2 create(EStyle timeStyle, EStyle dateStyle, const Locale& inLocale);
879 
880 
881     /**
882      * enum set of active boolean attributes for this instance
883      */
884     EnumSet<UDateFormatBooleanAttribute, 0, UDAT_BOOLEAN_ATTRIBUTE_COUNT> fBoolFlags;
885 
886 
887     UDisplayContext fCapitalizationContext;
888     friend class DateFmtKeyByStyle;
889 
890 public:
891 #ifndef U_HIDE_OBSOLETE_API
892     /**
893      * Field selector for FieldPosition for DateFormat fields.
894      * @obsolete ICU 3.4 use UDateFormatField instead, since this API will be
895      * removed in that release
896      */
897     enum EField
898     {
899         // Obsolete; use UDateFormatField instead
900         kEraField = UDAT_ERA_FIELD,
901         kYearField = UDAT_YEAR_FIELD,
902         kMonthField = UDAT_MONTH_FIELD,
903         kDateField = UDAT_DATE_FIELD,
904         kHourOfDay1Field = UDAT_HOUR_OF_DAY1_FIELD,
905         kHourOfDay0Field = UDAT_HOUR_OF_DAY0_FIELD,
906         kMinuteField = UDAT_MINUTE_FIELD,
907         kSecondField = UDAT_SECOND_FIELD,
908         kMillisecondField = UDAT_FRACTIONAL_SECOND_FIELD,
909         kDayOfWeekField = UDAT_DAY_OF_WEEK_FIELD,
910         kDayOfYearField = UDAT_DAY_OF_YEAR_FIELD,
911         kDayOfWeekInMonthField = UDAT_DAY_OF_WEEK_IN_MONTH_FIELD,
912         kWeekOfYearField = UDAT_WEEK_OF_YEAR_FIELD,
913         kWeekOfMonthField = UDAT_WEEK_OF_MONTH_FIELD,
914         kAmPmField = UDAT_AM_PM_FIELD,
915         kHour1Field = UDAT_HOUR1_FIELD,
916         kHour0Field = UDAT_HOUR0_FIELD,
917         kTimezoneField = UDAT_TIMEZONE_FIELD,
918         kYearWOYField = UDAT_YEAR_WOY_FIELD,
919         kDOWLocalField = UDAT_DOW_LOCAL_FIELD,
920         kExtendedYearField = UDAT_EXTENDED_YEAR_FIELD,
921         kJulianDayField = UDAT_JULIAN_DAY_FIELD,
922         kMillisecondsInDayField = UDAT_MILLISECONDS_IN_DAY_FIELD,
923 
924         // Obsolete; use UDateFormatField instead
925         ERA_FIELD = UDAT_ERA_FIELD,
926         YEAR_FIELD = UDAT_YEAR_FIELD,
927         MONTH_FIELD = UDAT_MONTH_FIELD,
928         DATE_FIELD = UDAT_DATE_FIELD,
929         HOUR_OF_DAY1_FIELD = UDAT_HOUR_OF_DAY1_FIELD,
930         HOUR_OF_DAY0_FIELD = UDAT_HOUR_OF_DAY0_FIELD,
931         MINUTE_FIELD = UDAT_MINUTE_FIELD,
932         SECOND_FIELD = UDAT_SECOND_FIELD,
933         MILLISECOND_FIELD = UDAT_FRACTIONAL_SECOND_FIELD,
934         DAY_OF_WEEK_FIELD = UDAT_DAY_OF_WEEK_FIELD,
935         DAY_OF_YEAR_FIELD = UDAT_DAY_OF_YEAR_FIELD,
936         DAY_OF_WEEK_IN_MONTH_FIELD = UDAT_DAY_OF_WEEK_IN_MONTH_FIELD,
937         WEEK_OF_YEAR_FIELD = UDAT_WEEK_OF_YEAR_FIELD,
938         WEEK_OF_MONTH_FIELD = UDAT_WEEK_OF_MONTH_FIELD,
939         AM_PM_FIELD = UDAT_AM_PM_FIELD,
940         HOUR1_FIELD = UDAT_HOUR1_FIELD,
941         HOUR0_FIELD = UDAT_HOUR0_FIELD,
942         TIMEZONE_FIELD = UDAT_TIMEZONE_FIELD
943     };
944 #endif  /* U_HIDE_OBSOLETE_API */
945 };
946 
947 U_NAMESPACE_END
948 
949 #endif /* #if !UCONFIG_NO_FORMATTING */
950 
951 #endif // _DATEFMT
952 //eof
953