1 /********************************************************************************
2 * Copyright (C) 2008-2013, International Business Machines Corporation and
3 * others. All Rights Reserved.
4 *******************************************************************************
5 *
6 * File DTITVFMT.H
7 *
8 *******************************************************************************
9 */
10 
11 #ifndef __DTITVFMT_H__
12 #define __DTITVFMT_H__
13 
14 
15 #include "unicode/utypes.h"
16 
17 /**
18  * \file
19  * \brief C++ API: Format and parse date interval in a language-independent manner.
20  */
21 
22 #if !UCONFIG_NO_FORMATTING
23 
24 #include "unicode/ucal.h"
25 #include "unicode/smpdtfmt.h"
26 #include "unicode/dtintrv.h"
27 #include "unicode/dtitvinf.h"
28 #include "unicode/dtptngen.h"
29 
30 U_NAMESPACE_BEGIN
31 
32 
33 
34 /**
35  * DateIntervalFormat is a class for formatting and parsing date
36  * intervals in a language-independent manner.
37  * Only formatting is supported, parsing is not supported.
38  *
39  * <P>
40  * Date interval means from one date to another date,
41  * for example, from "Jan 11, 2008" to "Jan 18, 2008".
42  * We introduced class DateInterval to represent it.
43  * DateInterval is a pair of UDate, which is
44  * the standard milliseconds since 24:00 GMT, Jan 1, 1970.
45  *
46  * <P>
47  * DateIntervalFormat formats a DateInterval into
48  * text as compactly as possible.
49  * For example, the date interval format from "Jan 11, 2008" to "Jan 18,. 2008"
50  * is "Jan 11-18, 2008" for English.
51  * And it parses text into DateInterval,
52  * although initially, parsing is not supported.
53  *
54  * <P>
55  * There is no structural information in date time patterns.
56  * For any punctuations and string literals inside a date time pattern,
57  * we do not know whether it is just a separator, or a prefix, or a suffix.
58  * Without such information, so, it is difficult to generate a sub-pattern
59  * (or super-pattern) by algorithm.
60  * So, formatting a DateInterval is pattern-driven. It is very
61  * similar to formatting in SimpleDateFormat.
62  * We introduce class DateIntervalInfo to save date interval
63  * patterns, similar to date time pattern in SimpleDateFormat.
64  *
65  * <P>
66  * Logically, the interval patterns are mappings
67  * from (skeleton, the_largest_different_calendar_field)
68  * to (date_interval_pattern).
69  *
70  * <P>
71  * A skeleton
72  * <ol>
73  * <li>
74  * only keeps the field pattern letter and ignores all other parts
75  * in a pattern, such as space, punctuations, and string literals.
76  * </li>
77  * <li>
78  * hides the order of fields.
79  * </li>
80  * <li>
81  * might hide a field's pattern letter length.
82  * </li>
83  * </ol>
84  *
85  * For those non-digit calendar fields, the pattern letter length is
86  * important, such as MMM, MMMM, and MMMMM; EEE and EEEE,
87  * and the field's pattern letter length is honored.
88  *
89  * For the digit calendar fields,  such as M or MM, d or dd, yy or yyyy,
90  * the field pattern length is ignored and the best match, which is defined
91  * in date time patterns, will be returned without honor the field pattern
92  * letter length in skeleton.
93  *
94  * <P>
95  * The calendar fields we support for interval formatting are:
96  * year, month, date, day-of-week, am-pm, hour, hour-of-day, and minute.
97  * Those calendar fields can be defined in the following order:
98  * year >  month > date > hour (in day) >  minute
99  *
100  * The largest different calendar fields between 2 calendars is the
101  * first different calendar field in above order.
102  *
103  * For example: the largest different calendar fields between "Jan 10, 2007"
104  * and "Feb 20, 2008" is year.
105  *
106  * <P>
107  * For other calendar fields, the compact interval formatting is not
108  * supported. And the interval format will be fall back to fall-back
109  * patterns, which is mostly "{date0} - {date1}".
110  *
111  * <P>
112  * There is a set of pre-defined static skeleton strings.
113  * There are pre-defined interval patterns for those pre-defined skeletons
114  * in locales' resource files.
115  * For example, for a skeleton UDAT_YEAR_ABBR_MONTH_DAY, which is  &quot;yMMMd&quot;,
116  * in  en_US, if the largest different calendar field between date1 and date2
117  * is &quot;year&quot;, the date interval pattern  is &quot;MMM d, yyyy - MMM d, yyyy&quot;,
118  * such as &quot;Jan 10, 2007 - Jan 10, 2008&quot;.
119  * If the largest different calendar field between date1 and date2 is &quot;month&quot;,
120  * the date interval pattern is &quot;MMM d - MMM d, yyyy&quot;,
121  * such as &quot;Jan 10 - Feb 10, 2007&quot;.
122  * If the largest different calendar field between date1 and date2 is &quot;day&quot;,
123  * the date interval pattern is &quot;MMM d-d, yyyy&quot;, such as &quot;Jan 10-20, 2007&quot;.
124  *
125  * For date skeleton, the interval patterns when year, or month, or date is
126  * different are defined in resource files.
127  * For time skeleton, the interval patterns when am/pm, or hour, or minute is
128  * different are defined in resource files.
129  *
130  * <P>
131  * If a skeleton is not found in a locale's DateIntervalInfo, which means
132  * the interval patterns for the skeleton is not defined in resource file,
133  * the interval pattern will falls back to the interval "fallback" pattern
134  * defined in resource file.
135  * If the interval "fallback" pattern is not defined, the default fall-back
136  * is "{date0} - {data1}".
137  *
138  * <P>
139  * For the combination of date and time,
140  * The rule to generate interval patterns are:
141  * <ol>
142  * <li>
143  *    when the year, month, or day differs, falls back to fall-back
144  *    interval pattern, which mostly is the concatenate the two original
145  *    expressions with a separator between,
146  *    For example, interval pattern from "Jan 10, 2007 10:10 am"
147  *    to "Jan 11, 2007 10:10am" is
148  *    "Jan 10, 2007 10:10 am - Jan 11, 2007 10:10am"
149  * </li>
150  * <li>
151  *    otherwise, present the date followed by the range expression
152  *    for the time.
153  *    For example, interval pattern from "Jan 10, 2007 10:10 am"
154  *    to "Jan 10, 2007 11:10am" is "Jan 10, 2007 10:10 am - 11:10am"
155  * </li>
156  * </ol>
157  *
158  *
159  * <P>
160  * If two dates are the same, the interval pattern is the single date pattern.
161  * For example, interval pattern from "Jan 10, 2007" to "Jan 10, 2007" is
162  * "Jan 10, 2007".
163  *
164  * Or if the presenting fields between 2 dates have the exact same values,
165  * the interval pattern is the  single date pattern.
166  * For example, if user only requests year and month,
167  * the interval pattern from "Jan 10, 2007" to "Jan 20, 2007" is "Jan 2007".
168  *
169  * <P>
170  * DateIntervalFormat needs the following information for correct
171  * formatting: time zone, calendar type, pattern, date format symbols,
172  * and date interval patterns.
173  * It can be instantiated in 2 ways:
174  * <ol>
175  * <li>
176  *    create an instance using default or given locale plus given skeleton.
177  *    Users are encouraged to created date interval formatter this way and
178  *    to use the pre-defined skeleton macros, such as
179  *    UDAT_YEAR_NUM_MONTH, which consists the calendar fields and
180  *    the format style.
181  * </li>
182  * <li>
183  *    create an instance using default or given locale plus given skeleton
184  *    plus a given DateIntervalInfo.
185  *    This factory method is for powerful users who want to provide their own
186  *    interval patterns.
187  *    Locale provides the timezone, calendar, and format symbols information.
188  *    Local plus skeleton provides full pattern information.
189  *    DateIntervalInfo provides the date interval patterns.
190  * </li>
191  * </ol>
192  *
193  * <P>
194  * For the calendar field pattern letter, such as G, y, M, d, a, h, H, m, s etc.
195  * DateIntervalFormat uses the same syntax as that of
196  * DateTime format.
197  *
198  * <P>
199  * Code Sample: general usage
200  * <pre>
201  * \code
202  *   // the date interval object which the DateIntervalFormat formats on
203  *   // and parses into
204  *   DateInterval*  dtInterval = new DateInterval(1000*3600*24, 1000*3600*24*2);
205  *   UErrorCode status = U_ZERO_ERROR;
206  *   DateIntervalFormat* dtIntervalFmt = DateIntervalFormat::createInstance(
207  *                           UDAT_YEAR_MONTH_DAY,
208  *                           Locale("en", "GB", ""), status);
209  *   UnicodeUnicodeString dateIntervalString;
210  *   FieldPosition pos = 0;
211  *   // formatting
212  *   dtIntervalFmt->format(dtInterval, dateIntervalUnicodeString, pos, status);
213  *   delete dtIntervalFmt;
214  * \endcode
215  * </pre>
216  */
217 
218 class U_I18N_API DateIntervalFormat : public Format {
219 public:
220 
221     /**
222      * Construct a DateIntervalFormat from skeleton and  the default locale.
223      *
224      * This is a convenient override of
225      * createInstance(const UnicodeString& skeleton, const Locale& locale,
226      *                UErrorCode&)
227      * with the value of locale as default locale.
228      *
229      * @param skeleton  the skeleton on which interval format based.
230      * @param status    output param set to success/failure code on exit
231      * @return          a date time interval formatter which the caller owns.
232      * @stable ICU 4.0
233      */
234     static DateIntervalFormat* U_EXPORT2 createInstance(
235                                                const UnicodeString& skeleton,
236                                                UErrorCode& status);
237 
238     /**
239      * Construct a DateIntervalFormat from skeleton and a given locale.
240      * <P>
241      * In this factory method,
242      * the date interval pattern information is load from resource files.
243      * Users are encouraged to created date interval formatter this way and
244      * to use the pre-defined skeleton macros.
245      *
246      * <P>
247      * There are pre-defined skeletons (defined in udate.h) having predefined
248      * interval patterns in resource files.
249      * Users are encouraged to use those macros.
250      * For example:
251      * DateIntervalFormat::createInstance(UDAT_MONTH_DAY, status)
252      *
253      * The given Locale provides the interval patterns.
254      * For example, for en_GB, if skeleton is UDAT_YEAR_ABBR_MONTH_WEEKDAY_DAY,
255      * which is "yMMMEEEd",
256      * the interval patterns defined in resource file to above skeleton are:
257      * "EEE, d MMM, yyyy - EEE, d MMM, yyyy" for year differs,
258      * "EEE, d MMM - EEE, d MMM, yyyy" for month differs,
259      * "EEE, d - EEE, d MMM, yyyy" for day differs,
260      * @param skeleton  the skeleton on which the interval format is based.
261      * @param locale    the given locale
262      * @param status    output param set to success/failure code on exit
263      * @return          a date time interval formatter which the caller owns.
264      * @stable ICU 4.0
265 	 * <p>
266 	 * <h4>Sample code</h4>
267 	 * \snippet samples/dtitvfmtsample/dtitvfmtsample.cpp dtitvfmtPreDefined1
268 	 * \snippet samples/dtitvfmtsample/dtitvfmtsample.cpp dtitvfmtPreDefined
269 	 * <p>
270      */
271 
272     static DateIntervalFormat* U_EXPORT2 createInstance(
273                                                const UnicodeString& skeleton,
274                                                const Locale& locale,
275                                                UErrorCode& status);
276 
277     /**
278      * Construct a DateIntervalFormat from skeleton
279      *  DateIntervalInfo, and default locale.
280      *
281      * This is a convenient override of
282      * createInstance(const UnicodeString& skeleton, const Locale& locale,
283      *                const DateIntervalInfo& dtitvinf, UErrorCode&)
284      * with the locale value as default locale.
285      *
286      * @param skeleton  the skeleton on which interval format based.
287      * @param dtitvinf  the DateIntervalInfo object.
288      * @param status    output param set to success/failure code on exit
289      * @return          a date time interval formatter which the caller owns.
290      * @stable ICU 4.0
291      */
292     static DateIntervalFormat* U_EXPORT2 createInstance(
293                                               const UnicodeString& skeleton,
294                                               const DateIntervalInfo& dtitvinf,
295                                               UErrorCode& status);
296 
297     /**
298      * Construct a DateIntervalFormat from skeleton
299      * a DateIntervalInfo, and the given locale.
300      *
301      * <P>
302      * In this factory method, user provides its own date interval pattern
303      * information, instead of using those pre-defined data in resource file.
304      * This factory method is for powerful users who want to provide their own
305      * interval patterns.
306      * <P>
307      * There are pre-defined skeletons (defined in udate.h) having predefined
308      * interval patterns in resource files.
309      * Users are encouraged to use those macros.
310      * For example:
311      * DateIntervalFormat::createInstance(UDAT_MONTH_DAY, status)
312      *
313      * The DateIntervalInfo provides the interval patterns.
314      * and the DateIntervalInfo ownership remains to the caller.
315      *
316      * User are encouraged to set default interval pattern in DateIntervalInfo
317      * as well, if they want to set other interval patterns ( instead of
318      * reading the interval patterns from resource files).
319      * When the corresponding interval pattern for a largest calendar different
320      * field is not found ( if user not set it ), interval format fallback to
321      * the default interval pattern.
322      * If user does not provide default interval pattern, it fallback to
323      * "{date0} - {date1}"
324      *
325      * @param skeleton  the skeleton on which interval format based.
326      * @param locale    the given locale
327      * @param dtitvinf  the DateIntervalInfo object.
328      * @param status    output param set to success/failure code on exit
329      * @return          a date time interval formatter which the caller owns.
330      * @stable ICU 4.0
331 	 * <p>
332 	 * <h4>Sample code</h4>
333 	 * \snippet samples/dtitvfmtsample/dtitvfmtsample.cpp dtitvfmtPreDefined1
334 	 * \snippet samples/dtitvfmtsample/dtitvfmtsample.cpp dtitvfmtCustomized
335 	 * <p>
336      */
337     static DateIntervalFormat* U_EXPORT2 createInstance(
338                                               const UnicodeString& skeleton,
339                                               const Locale& locale,
340                                               const DateIntervalInfo& dtitvinf,
341                                               UErrorCode& status);
342 
343     /**
344      * Destructor.
345      * @stable ICU 4.0
346      */
347     virtual ~DateIntervalFormat();
348 
349     /**
350      * Clone this Format object polymorphically. The caller owns the result and
351      * should delete it when done.
352      * @return    A copy of the object.
353      * @stable ICU 4.0
354      */
355     virtual Format* clone(void) const;
356 
357     /**
358      * Return true if the given Format objects are semantically equal. Objects
359      * of different subclasses are considered unequal.
360      * @param other    the object to be compared with.
361      * @return         true if the given Format objects are semantically equal.
362      * @stable ICU 4.0
363      */
364     virtual UBool operator==(const Format& other) const;
365 
366     /**
367      * Return true if the given Format objects are not semantically equal.
368      * Objects of different subclasses are considered unequal.
369      * @param other the object to be compared with.
370      * @return      true if the given Format objects are not semantically equal.
371      * @stable ICU 4.0
372      */
373     UBool operator!=(const Format& other) const;
374 
375 
376     using Format::format;
377 
378     /**
379      * Format an object to produce a string. This method handles Formattable
380      * objects with a DateInterval type.
381      * If a the Formattable object type is not a DateInterval,
382      * then it returns a failing UErrorCode.
383      *
384      * @param obj               The object to format.
385      *                          Must be a DateInterval.
386      * @param appendTo          Output parameter to receive result.
387      *                          Result is appended to existing contents.
388      * @param fieldPosition     On input: an alignment field, if desired.
389      *                          On output: the offsets of the alignment field.
390      * @param status            Output param filled with success/failure status.
391      * @return                  Reference to 'appendTo' parameter.
392      * @stable ICU 4.0
393      */
394     virtual UnicodeString& format(const Formattable& obj,
395                                   UnicodeString& appendTo,
396                                   FieldPosition& fieldPosition,
397                                   UErrorCode& status) const ;
398 
399 
400 
401     /**
402      * Format a DateInterval to produce a string.
403      *
404      * @param dtInterval        DateInterval to be formatted.
405      * @param appendTo          Output parameter to receive result.
406      *                          Result is appended to existing contents.
407      * @param fieldPosition     On input: an alignment field, if desired.
408      *                          On output: the offsets of the alignment field.
409      * @param status            Output param filled with success/failure status.
410      * @return                  Reference to 'appendTo' parameter.
411      * @stable ICU 4.0
412      */
413     UnicodeString& format(const DateInterval* dtInterval,
414                           UnicodeString& appendTo,
415                           FieldPosition& fieldPosition,
416                           UErrorCode& status) const ;
417 
418 
419     /**
420      * Format 2 Calendars to produce a string.
421      *
422      * Note: "fromCalendar" and "toCalendar" are not const,
423      * since calendar is not const in  SimpleDateFormat::format(Calendar&),
424      *
425      * @param fromCalendar      calendar set to the from date in date interval
426      *                          to be formatted into date interval string
427      * @param toCalendar        calendar set to the to date in date interval
428      *                          to be formatted into date interval string
429      * @param appendTo          Output parameter to receive result.
430      *                          Result is appended to existing contents.
431      * @param fieldPosition     On input: an alignment field, if desired.
432      *                          On output: the offsets of the alignment field.
433      * @param status            Output param filled with success/failure status.
434      *                          Caller needs to make sure it is SUCCESS
435      *                          at the function entrance
436      * @return                  Reference to 'appendTo' parameter.
437      * @stable ICU 4.0
438      */
439     UnicodeString& format(Calendar& fromCalendar,
440                           Calendar& toCalendar,
441                           UnicodeString& appendTo,
442                           FieldPosition& fieldPosition,
443                           UErrorCode& status) const ;
444 
445     /**
446      * Date interval parsing is not supported. Please do not use.
447      * <P>
448      * This method should handle parsing of
449      * date time interval strings into Formattable objects with
450      * DateInterval type, which is a pair of UDate.
451      * <P>
452      * Before calling, set parse_pos.index to the offset you want to start
453      * parsing at in the source. After calling, parse_pos.index is the end of
454      * the text you parsed. If error occurs, index is unchanged.
455      * <P>
456      * When parsing, leading whitespace is discarded (with a successful parse),
457      * while trailing whitespace is left as is.
458      * <P>
459      * See Format::parseObject() for more.
460      *
461      * @param source    The string to be parsed into an object.
462      * @param result    Formattable to be set to the parse result.
463      *                  If parse fails, return contents are undefined.
464      * @param parse_pos The position to start parsing at. Since no parsing
465      *                  is supported, upon return this param is unchanged.
466      * @return          A newly created Formattable* object, or NULL
467      *                  on failure.  The caller owns this and should
468      *                  delete it when done.
469      * @internal ICU 4.0
470      */
471     virtual void parseObject(const UnicodeString& source,
472                              Formattable& result,
473                              ParsePosition& parse_pos) const;
474 
475 
476     /**
477      * Gets the date time interval patterns.
478      * @return the date time interval patterns associated with
479      * this date interval formatter.
480      * @stable ICU 4.0
481      */
482     const DateIntervalInfo* getDateIntervalInfo(void) const;
483 
484 
485     /**
486      * Set the date time interval patterns.
487      * @param newIntervalPatterns   the given interval patterns to copy.
488      * @param status          output param set to success/failure code on exit
489      * @stable ICU 4.0
490      */
491     void setDateIntervalInfo(const DateIntervalInfo& newIntervalPatterns,
492                              UErrorCode& status);
493 
494 
495     /**
496      * Gets the date formatter
497      * @return the date formatter associated with this date interval formatter.
498      * @stable ICU 4.0
499      */
500     const DateFormat* getDateFormat(void) const;
501 
502     /**
503      * Returns a reference to the TimeZone used by this DateIntervalFormat's calendar.
504      * @return the time zone associated with the calendar of DateIntervalFormat.
505      * @stable ICU 4.8
506      */
507     virtual const TimeZone& getTimeZone(void) const;
508 
509     /**
510      * Sets the time zone for the calendar used by this DateIntervalFormat object. The
511      * caller no longer owns the TimeZone object and should not delete it after this call.
512      * @param zoneToAdopt the TimeZone to be adopted.
513      * @stable ICU 4.8
514      */
515     virtual void adoptTimeZone(TimeZone* zoneToAdopt);
516 
517     /**
518      * Sets the time zone for the calendar used by this DateIntervalFormat object.
519      * @param zone the new time zone.
520      * @stable ICU 4.8
521      */
522     virtual void setTimeZone(const TimeZone& zone);
523 
524     /**
525      * Return the class ID for this class. This is useful only for comparing to
526      * a return value from getDynamicClassID(). For example:
527      * <pre>
528      * .   Base* polymorphic_pointer = createPolymorphicObject();
529      * .   if (polymorphic_pointer->getDynamicClassID() ==
530      * .       erived::getStaticClassID()) ...
531      * </pre>
532      * @return          The class ID for all objects of this class.
533      * @stable ICU 4.0
534      */
535     static UClassID U_EXPORT2 getStaticClassID(void);
536 
537     /**
538      * Returns a unique class ID POLYMORPHICALLY. Pure virtual override. This
539      * method is to implement a simple version of RTTI, since not all C++
540      * compilers support genuine RTTI. Polymorphic operator==() and clone()
541      * methods call this method.
542      *
543      * @return          The class ID for this object. All objects of a
544      *                  given class have the same class ID.  Objects of
545      *                  other classes have different class IDs.
546      * @stable ICU 4.0
547      */
548     virtual UClassID getDynamicClassID(void) const;
549 
550 protected:
551 
552     /**
553      * Copy constructor.
554      * @stable ICU 4.0
555      */
556     DateIntervalFormat(const DateIntervalFormat&);
557 
558     /**
559      * Assignment operator.
560      * @stable ICU 4.0
561      */
562     DateIntervalFormat& operator=(const DateIntervalFormat&);
563 
564 private:
565 
566     /*
567      * This is for ICU internal use only. Please do not use.
568      * Save the interval pattern information.
569      * Interval pattern consists of 2 single date patterns and the separator.
570      * For example, interval pattern "MMM d - MMM d, yyyy" consists
571      * a single date pattern "MMM d", another single date pattern "MMM d, yyyy",
572      * and a separator "-".
573      * The pattern is divided into 2 parts. For above example,
574      * the first part is "MMM d - ", and the second part is "MMM d, yyyy".
575      * Also, the first date appears in an interval pattern could be
576      * the earlier date or the later date.
577      * And such information is saved in the interval pattern as well.
578      */
579     struct PatternInfo {
580         UnicodeString firstPart;
581         UnicodeString secondPart;
582         /**
583          * Whether the first date in interval pattern is later date or not.
584          * Fallback format set the default ordering.
585          * And for a particular interval pattern, the order can be
586          * overriden by prefixing the interval pattern with "latestFirst:" or
587          * "earliestFirst:"
588          * For example, given 2 date, Jan 10, 2007 to Feb 10, 2007.
589          * if the fallback format is "{0} - {1}",
590          * and the pattern is "d MMM - d MMM yyyy", the interval format is
591          * "10 Jan - 10 Feb, 2007".
592          * If the pattern is "latestFirst:d MMM - d MMM yyyy",
593          * the interval format is "10 Feb - 10 Jan, 2007"
594          */
595         UBool         laterDateFirst;
596     };
597 
598 
599     /**
600      * default constructor
601      * @internal ICU 4.0
602      */
603     DateIntervalFormat();
604 
605     /**
606      * Construct a DateIntervalFormat from DateFormat,
607      * a DateIntervalInfo, and skeleton.
608      * DateFormat provides the timezone, calendar,
609      * full pattern, and date format symbols information.
610      * It should be a SimpleDateFormat object which
611      * has a pattern in it.
612      * the DateIntervalInfo provides the interval patterns.
613      *
614      * Note: the DateIntervalFormat takes ownership of both
615      * DateFormat and DateIntervalInfo objects.
616      * Caller should not delete them.
617      *
618      * @param locale    the locale of this date interval formatter.
619      * @param dtItvInfo the DateIntervalInfo object to be adopted.
620      * @param skeleton  the skeleton of the date formatter
621      * @param status    output param set to success/failure code on exit
622      */
623     DateIntervalFormat(const Locale& locale, DateIntervalInfo* dtItvInfo,
624                        const UnicodeString* skeleton, UErrorCode& status);
625 
626 
627     /**
628      * Construct a DateIntervalFormat from DateFormat
629      * and a DateIntervalInfo.
630      *
631      * It is a wrapper of the constructor.
632      *
633      * @param locale    the locale of this date interval formatter.
634      * @param dtitvinf  the DateIntervalInfo object to be adopted.
635      * @param skeleton  the skeleton of this formatter.
636      * @param status    Output param set to success/failure code.
637      * @return          a date time interval formatter which the caller owns.
638      */
639     static DateIntervalFormat* U_EXPORT2 create(const Locale& locale,
640                                                 DateIntervalInfo* dtitvinf,
641                                                 const UnicodeString* skeleton,
642                                                 UErrorCode& status);
643 
644     /**
645      * Create a simple date/time formatter from skeleton, given locale,
646      * and date time pattern generator.
647      *
648      * @param skeleton  the skeleton on which date format based.
649      * @param locale    the given locale.
650      * @param dtpng     the date time pattern generator.
651      * @param status    Output param to be set to success/failure code.
652      *                  If it is failure, the returned date formatter will
653      *                  be NULL.
654      * @return          a simple date formatter which the caller owns.
655      */
656     static SimpleDateFormat* U_EXPORT2 createSDFPatternInstance(
657                                         const UnicodeString& skeleton,
658                                         const Locale& locale,
659                                         DateTimePatternGenerator* dtpng,
660                                         UErrorCode& status);
661 
662 
663     /**
664      *  Below are for generating interval patterns local to the formatter
665      */
666 
667 
668     /**
669      * Format 2 Calendars using fall-back interval pattern
670      *
671      * The full pattern used in this fall-back format is the
672      * full pattern of the date formatter.
673      *
674      * @param fromCalendar      calendar set to the from date in date interval
675      *                          to be formatted into date interval string
676      * @param toCalendar        calendar set to the to date in date interval
677      *                          to be formatted into date interval string
678      * @param appendTo          Output parameter to receive result.
679      *                          Result is appended to existing contents.
680      * @param pos               On input: an alignment field, if desired.
681      *                          On output: the offsets of the alignment field.
682      * @param status            output param set to success/failure code on exit
683      * @return                  Reference to 'appendTo' parameter.
684      */
685     UnicodeString& fallbackFormat(Calendar& fromCalendar,
686                                   Calendar& toCalendar,
687                                   UnicodeString& appendTo,
688                                   FieldPosition& pos,
689                                   UErrorCode& status) const;
690 
691 
692 
693     /**
694      * Initialize interval patterns locale to this formatter
695      *
696      * This code is a bit complicated since
697      * 1. the interval patterns saved in resource bundle files are interval
698      *    patterns based on date or time only.
699      *    It does not have interval patterns based on both date and time.
700      *    Interval patterns on both date and time are algorithm generated.
701      *
702      *    For example, it has interval patterns on skeleton "dMy" and "hm",
703      *    but it does not have interval patterns on skeleton "dMyhm".
704      *
705      *    The rule to generate interval patterns for both date and time skeleton are
706      *    1) when the year, month, or day differs, concatenate the two original
707      *    expressions with a separator between,
708      *    For example, interval pattern from "Jan 10, 2007 10:10 am"
709      *    to "Jan 11, 2007 10:10am" is
710      *    "Jan 10, 2007 10:10 am - Jan 11, 2007 10:10am"
711      *
712      *    2) otherwise, present the date followed by the range expression
713      *    for the time.
714      *    For example, interval pattern from "Jan 10, 2007 10:10 am"
715      *    to "Jan 10, 2007 11:10am" is
716      *    "Jan 10, 2007 10:10 am - 11:10am"
717      *
718      * 2. even a pattern does not request a certain calendar field,
719      *    the interval pattern needs to include such field if such fields are
720      *    different between 2 dates.
721      *    For example, a pattern/skeleton is "hm", but the interval pattern
722      *    includes year, month, and date when year, month, and date differs.
723      *
724      *
725      * @param status    output param set to success/failure code on exit
726      */
727     void initializePattern(UErrorCode& status);
728 
729 
730 
731     /**
732      * Set fall back interval pattern given a calendar field,
733      * a skeleton, and a date time pattern generator.
734      * @param field      the largest different calendar field
735      * @param skeleton   a skeleton
736      * @param status     output param set to success/failure code on exit
737      */
738     void setFallbackPattern(UCalendarDateFields field,
739                             const UnicodeString& skeleton,
740                             UErrorCode& status);
741 
742 
743 
744     /**
745      * get separated date and time skeleton from a combined skeleton.
746      *
747      * The difference between date skeleton and normalizedDateSkeleton are:
748      * 1. both 'y' and 'd' are appeared only once in normalizeDateSkeleton
749      * 2. 'E' and 'EE' are normalized into 'EEE'
750      * 3. 'MM' is normalized into 'M'
751      *
752      ** the difference between time skeleton and normalizedTimeSkeleton are:
753      * 1. both 'H' and 'h' are normalized as 'h' in normalized time skeleton,
754      * 2. 'a' is omitted in normalized time skeleton.
755      * 3. there is only one appearance for 'h', 'm','v', 'z' in normalized time
756      *    skeleton
757      *
758      *
759      *  @param skeleton               given combined skeleton.
760      *  @param date                   Output parameter for date only skeleton.
761      *  @param normalizedDate         Output parameter for normalized date only
762      *
763      *  @param time                   Output parameter for time only skeleton.
764      *  @param normalizedTime         Output parameter for normalized time only
765      *                                skeleton.
766      *
767      */
768     static void  U_EXPORT2 getDateTimeSkeleton(const UnicodeString& skeleton,
769                                     UnicodeString& date,
770                                     UnicodeString& normalizedDate,
771                                     UnicodeString& time,
772                                     UnicodeString& normalizedTime);
773 
774 
775 
776     /**
777      * Generate date or time interval pattern from resource,
778      * and set them into the interval pattern locale to this formatter.
779      *
780      * It needs to handle the following:
781      * 1. need to adjust field width.
782      *    For example, the interval patterns saved in DateIntervalInfo
783      *    includes "dMMMy", but not "dMMMMy".
784      *    Need to get interval patterns for dMMMMy from dMMMy.
785      *    Another example, the interval patterns saved in DateIntervalInfo
786      *    includes "hmv", but not "hmz".
787      *    Need to get interval patterns for "hmz' from 'hmv'
788      *
789      * 2. there might be no pattern for 'y' differ for skeleton "Md",
790      *    in order to get interval patterns for 'y' differ,
791      *    need to look for it from skeleton 'yMd'
792      *
793      * @param dateSkeleton   normalized date skeleton
794      * @param timeSkeleton   normalized time skeleton
795      * @return               whether the resource is found for the skeleton.
796      *                       TRUE if interval pattern found for the skeleton,
797      *                       FALSE otherwise.
798      */
799     UBool setSeparateDateTimePtn(const UnicodeString& dateSkeleton,
800                                  const UnicodeString& timeSkeleton);
801 
802 
803 
804 
805     /**
806      * Generate interval pattern from existing resource
807      *
808      * It not only save the interval patterns,
809      * but also return the extended skeleton and its best match skeleton.
810      *
811      * @param field           largest different calendar field
812      * @param skeleton        skeleton
813      * @param bestSkeleton    the best match skeleton which has interval pattern
814      *                        defined in resource
815      * @param differenceInfo  the difference between skeleton and best skeleton
816      *         0 means the best matched skeleton is the same as input skeleton
817      *         1 means the fields are the same, but field width are different
818      *         2 means the only difference between fields are v/z,
819      *        -1 means there are other fields difference
820      *
821      * @param extendedSkeleton      extended skeleton
822      * @param extendedBestSkeleton  extended best match skeleton
823      * @return                      whether the interval pattern is found
824      *                              through extending skeleton or not.
825      *                              TRUE if interval pattern is found by
826      *                              extending skeleton, FALSE otherwise.
827      */
828     UBool setIntervalPattern(UCalendarDateFields field,
829                              const UnicodeString* skeleton,
830                              const UnicodeString* bestSkeleton,
831                              int8_t differenceInfo,
832                              UnicodeString* extendedSkeleton = NULL,
833                              UnicodeString* extendedBestSkeleton = NULL);
834 
835     /**
836      * Adjust field width in best match interval pattern to match
837      * the field width in input skeleton.
838      *
839      * TODO (xji) make a general solution
840      * The adjusting rule can be:
841      * 1. always adjust
842      * 2. never adjust
843      * 3. default adjust, which means adjust according to the following rules
844      * 3.1 always adjust string, such as MMM and MMMM
845      * 3.2 never adjust between string and numeric, such as MM and MMM
846      * 3.3 always adjust year
847      * 3.4 do not adjust 'd', 'h', or 'm' if h presents
848      * 3.5 do not adjust 'M' if it is numeric(?)
849      *
850      * Since date interval format is well-formed format,
851      * date and time skeletons are normalized previously,
852      * till this stage, the adjust here is only "adjust strings, such as MMM
853      * and MMMM, EEE and EEEE.
854      *
855      * @param inputSkeleton            the input skeleton
856      * @param bestMatchSkeleton        the best match skeleton
857      * @param bestMatchIntervalPattern the best match interval pattern
858      * @param differenceInfo           the difference between 2 skeletons
859      *                                 1 means only field width differs
860      *                                 2 means v/z exchange
861      * @param adjustedIntervalPattern  adjusted interval pattern
862      */
863     static void U_EXPORT2 adjustFieldWidth(
864                             const UnicodeString& inputSkeleton,
865                             const UnicodeString& bestMatchSkeleton,
866                             const UnicodeString& bestMatchIntervalPattern,
867                             int8_t differenceInfo,
868                             UnicodeString& adjustedIntervalPattern);
869 
870     /**
871      * Concat a single date pattern with a time interval pattern,
872      * set it into the intervalPatterns, while field is time field.
873      * This is used to handle time interval patterns on skeleton with
874      * both time and date. Present the date followed by
875      * the range expression for the time.
876      * @param format         date and time format
877      * @param formatLen      format string length
878      * @param datePattern    date pattern
879      * @param field          time calendar field: AM_PM, HOUR, MINUTE
880      * @param status         output param set to success/failure code on exit
881      */
882     void concatSingleDate2TimeInterval(const UChar* format,
883                                        int32_t formatLen,
884                                        const UnicodeString& datePattern,
885                                        UCalendarDateFields field,
886                                        UErrorCode& status);
887 
888     /**
889      * check whether a calendar field present in a skeleton.
890      * @param field      calendar field need to check
891      * @param skeleton   given skeleton on which to check the calendar field
892      * @return           true if field present in a skeleton.
893      */
894     static UBool U_EXPORT2 fieldExistsInSkeleton(UCalendarDateFields field,
895                                                  const UnicodeString& skeleton);
896 
897 
898     /**
899      * Split interval patterns into 2 part.
900      * @param intervalPattern  interval pattern
901      * @return the index in interval pattern which split the pattern into 2 part
902      */
903     static int32_t  U_EXPORT2 splitPatternInto2Part(const UnicodeString& intervalPattern);
904 
905 
906     /**
907      * Break interval patterns as 2 part and save them into pattern info.
908      * @param field            calendar field
909      * @param intervalPattern  interval pattern
910      */
911     void setIntervalPattern(UCalendarDateFields field,
912                             const UnicodeString& intervalPattern);
913 
914 
915     /**
916      * Break interval patterns as 2 part and save them into pattern info.
917      * @param field            calendar field
918      * @param intervalPattern  interval pattern
919      * @param laterDateFirst   whether later date appear first in interval pattern
920      */
921     void setIntervalPattern(UCalendarDateFields field,
922                             const UnicodeString& intervalPattern,
923                             UBool laterDateFirst);
924 
925 
926     /**
927      * Set pattern information.
928      *
929      * @param field            calendar field
930      * @param firstPart        the first part in interval pattern
931      * @param secondPart       the second part in interval pattern
932      * @param laterDateFirst   whether the first date in intervalPattern
933      *                         is earlier date or later date
934      */
935     void setPatternInfo(UCalendarDateFields field,
936                         const UnicodeString* firstPart,
937                         const UnicodeString* secondPart,
938                         UBool laterDateFirst);
939 
940 
941     // from calendar field to pattern letter
942     static const UChar fgCalendarFieldToPatternLetter[];
943 
944 
945     /**
946      * The interval patterns for this locale.
947      */
948     DateIntervalInfo*     fInfo;
949 
950     /**
951      * The DateFormat object used to format single pattern
952      */
953     SimpleDateFormat*     fDateFormat;
954 
955     /**
956      * The 2 calendars with the from and to date.
957      * could re-use the calendar in fDateFormat,
958      * but keeping 2 calendars make it clear and clean.
959      */
960     Calendar* fFromCalendar;
961     Calendar* fToCalendar;
962 
963     /**
964      * Date time pattern generator
965      */
966     DateTimePatternGenerator* fDtpng;
967 
968     /**
969      * Following are interval information relavent (locale) to this formatter.
970      */
971     UnicodeString fSkeleton;
972     PatternInfo fIntervalPatterns[DateIntervalInfo::kIPI_MAX_INDEX];
973 };
974 
975 inline UBool
976 DateIntervalFormat::operator!=(const Format& other) const  {
977     return !operator==(other);
978 }
979 
980 U_NAMESPACE_END
981 
982 #endif /* #if !UCONFIG_NO_FORMATTING */
983 
984 #endif // _DTITVFMT_H__
985 //eof
986