scuffed-code/icu4c/source/i18n/calendar.cpp
Unknown User aa0b0a88e8 Initial revision
X-SVN-Rev: 2
1999-08-16 21:50:52 +00:00

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C++

/*
*******************************************************************************
* *
* COPYRIGHT: *
* (C) Copyright Taligent, Inc., 1997 *
* (C) Copyright International Business Machines Corporation, 1997-1998 *
* Licensed Material - Program-Property of IBM - All Rights Reserved. *
* US Government Users Restricted Rights - Use, duplication, or disclosure *
* restricted by GSA ADP Schedule Contract with IBM Corp. *
* *
*******************************************************************************
*
* File CALENDAR.CPP
*
* Modification History:
*
* Date Name Description
* 02/03/97 clhuang Creation.
* 04/22/97 aliu Cleaned up, fixed memory leak, made
* setWeekCountData() more robust.
* Moved platform code to TPlatformUtilities.
* 05/01/97 aliu Made equals(), before(), after() arguments const.
* 05/20/97 aliu Changed logic of when to compute fields and time
* to fix bugs.
* 08/12/97 aliu Added equivalentTo. Misc other fixes.
* 07/28/98 stephen Sync up with JDK 1.2
* 09/02/98 stephen Sync with JDK 1.2 8/31 build (getActualMin/Max)
* 03/17/99 stephen Changed adoptTimeZone() - now fAreFieldsSet is
* set to FALSE to force update of time.
*******************************************************************************
*/
#include "resbund.h"
#include "gregocal.h"
// Resource bundle tags read by this class
const char* Calendar::kDateTimeElements = "DateTimeElements";
// Data flow in Calendar
// ---------------------
// The current time is represented in two ways by Calendar: as UTC
// milliseconds from the epoch start (1 January 1970 0:00 UTC), and as local
// fields such as MONTH, HOUR, AM_PM, etc. It is possible to compute the
// millis from the fields, and vice versa. The data needed to do this
// conversion is encapsulated by a TimeZone object owned by the Calendar.
// The data provided by the TimeZone object may also be overridden if the
// user sets the ZONE_OFFSET and/or DST_OFFSET fields directly. The class
// keeps track of what information was most recently set by the caller, and
// uses that to compute any other information as needed.
// If the user sets the fields using set(), the data flow is as follows.
// This is implemented by the Calendar subclass's computeTime() method.
// During this process, certain fields may be ignored. The disambiguation
// algorithm for resolving which fields to pay attention to is described
// above.
// local fields (YEAR, MONTH, DATE, HOUR, MINUTE, etc.)
// |
// | Using Calendar-specific algorithm
// V
// local standard millis
// |
// | Using TimeZone or user-set ZONE_OFFSET / DST_OFFSET
// V
// UTC millis (in time data member)
// If the user sets the UTC millis using setTime(), the data flow is as
// follows. This is implemented by the Calendar subclass's computeFields()
// method.
// UTC millis (in time data member)
// |
// | Using TimeZone getOffset()
// V
// local standard millis
// |
// | Using Calendar-specific algorithm
// V
// local fields (YEAR, MONTH, DATE, HOUR, MINUTE, etc.)
// In general, a round trip from fields, through local and UTC millis, and
// back out to fields is made when necessary. This is implemented by the
// complete() method. Resolving a partial set of fields into a UTC millis
// value allows all remaining fields to be generated from that value. If
// the Calendar is lenient, the fields are also renormalized to standard
// ranges when they are regenerated.
// -------------------------------------
Calendar::Calendar(UErrorCode& success)
: fTime(0),
fIsTimeSet(FALSE),
fAreFieldsSet(FALSE),
fAreAllFieldsSet(FALSE),
fLenient(TRUE),
fZone(0),
fNextStamp(kMinimumUserStamp)
{
clear();
fZone = TimeZone::createDefault();
setWeekCountData(Locale::getDefault(), success);
}
// -------------------------------------
Calendar::Calendar(TimeZone* zone, const Locale& aLocale, UErrorCode& success)
: fTime(0),
fIsTimeSet(FALSE),
fAreFieldsSet(FALSE),
fAreAllFieldsSet(FALSE),
fLenient(TRUE),
fZone(0),
fNextStamp(kMinimumUserStamp)
{
if(zone == 0) {
success = ILLEGAL_ARGUMENT_ERROR;
return;
}
clear();
fZone = zone;
setWeekCountData(aLocale, success);
}
// -------------------------------------
Calendar::Calendar(const TimeZone& zone, const Locale& aLocale, UErrorCode& success)
: fTime(0),
fIsTimeSet(FALSE),
fAreFieldsSet(FALSE),
fAreAllFieldsSet(FALSE),
fLenient(TRUE),
fZone(0),
fNextStamp(kMinimumUserStamp)
{
clear();
fZone = zone.clone();
setWeekCountData(aLocale, success);
}
// -------------------------------------
Calendar::~Calendar()
{
delete fZone;
}
// -------------------------------------
Calendar::Calendar(const Calendar &source)
{
fZone = 0;
*this = source;
}
// -------------------------------------
Calendar &
Calendar::operator=(const Calendar &right)
{
if (this != &right)
{
icu_arrayCopy(right.fFields, fFields, FIELD_COUNT);
icu_arrayCopy(right.fIsSet, fIsSet, FIELD_COUNT);
icu_arrayCopy(right.fStamp, fStamp, FIELD_COUNT);
fTime = right.fTime;
fIsTimeSet = right.fIsTimeSet;
fAreAllFieldsSet = right.fAreAllFieldsSet;
fAreFieldsSet = right.fAreFieldsSet;
fLenient = right.fLenient;
delete fZone;
fZone = right.fZone->clone();
fFirstDayOfWeek = right.fFirstDayOfWeek;
fMinimalDaysInFirstWeek = right.fMinimalDaysInFirstWeek;
fNextStamp = right.fNextStamp;
}
return *this;
}
// -------------------------------------
Calendar*
Calendar::createInstance(UErrorCode& success)
{
if (FAILURE(success)) return 0;
// right now, createInstance will always return an instance of GregorianCalendar
Calendar* c = new GregorianCalendar(success);
if (FAILURE(success)) { delete c; c = 0; }
return c;
}
// -------------------------------------
Calendar*
Calendar::createInstance(TimeZone* zone, UErrorCode& success)
{
if (FAILURE(success)) return 0;
// since the Locale isn't specified, use the default locale
Calendar* c = new GregorianCalendar(zone, Locale::getDefault(), success);
if (FAILURE(success)) { delete c; c = 0; }
return c;
}
// -------------------------------------
Calendar*
Calendar::createInstance(const TimeZone& zone, UErrorCode& success)
{
if (FAILURE(success)) return 0;
// since the Locale isn't specified, use the default locale
Calendar* c = new GregorianCalendar(zone, Locale::getDefault(), success);
if (FAILURE(success)) { delete c; c = 0; }
return c;
}
// -------------------------------------
Calendar*
Calendar::createInstance(const Locale& aLocale, UErrorCode& success)
{
if (FAILURE(success)) return 0;
// since the TimeZone isn't specfied, use the default time zone
Calendar* c = new GregorianCalendar(TimeZone::createDefault(), aLocale, success);
if (FAILURE(success)) { delete c; c = 0; }
return c;
}
// -------------------------------------
Calendar*
Calendar::createInstance(TimeZone* zone, const Locale& aLocale, UErrorCode& success)
{
if (FAILURE(success)) return 0;
Calendar* c = new GregorianCalendar(zone, aLocale, success);
if (FAILURE(success)) { delete c; c = 0; }
return c;
}
// -------------------------------------
Calendar*
Calendar::createInstance(const TimeZone& zone, const Locale& aLocale, UErrorCode& success)
{
if (FAILURE(success)) return 0;
Calendar* c = new GregorianCalendar(zone, aLocale, success);
if (FAILURE(success)) { delete c; c = 0; }
return c;
}
// -------------------------------------
bool_t
Calendar::operator==(const Calendar& that) const
{
UErrorCode status = ZERO_ERROR;
// {sfb} is this correct? (Java equals)
return (getDynamicClassID() == that.getDynamicClassID() &&
getTimeInMillis(status) == that.getTimeInMillis(status) &&
fLenient == that.fLenient &&
fFirstDayOfWeek == that.fFirstDayOfWeek &&
fMinimalDaysInFirstWeek == that.fMinimalDaysInFirstWeek &&
*fZone == *(that.fZone));
// As it stands, this is a very narrowly defined ==, since the
// Calendars must not only represent the same time; they must
// also be in exactly the same state. This would be looser if
// we forced field or fTime computation, and then did the comparison.
/*
if (this == &that) return TRUE;
for (int32_t i=0; i<FIELD_COUNT; ++i)
{
if (fFields[i] != that.fFields[i] ||
fIsSet[i] != that.fIsSet[i]) return FALSE;
}
return (getDynamicClassID() == that.getDynamicClassID() &&
fTime == that.fTime &&
fIsTimeSet == that.fIsTimeSet &&
fAreAllFieldsSet == that.fAreAllFieldsSet &&
fAreFieldsSet == that.fAreFieldsSet &&
fLenient == that.fLenient &&
(!fIsSet[ZONE_OFFSET] || (fUserSetZoneOffset == that.fUserSetZoneOffset)) &&
(!fIsSet[DST_OFFSET] || (fUserSetDSTOffset == that.fUserSetDSTOffset)) &&
fFirstDayOfWeek == that.fFirstDayOfWeek &&
fMinimalDaysInFirstWeek == that.fMinimalDaysInFirstWeek &&
*fZone == *(that.fZone));
*/
}
// -------------------------------------
bool_t
Calendar::equals(const Calendar& when, UErrorCode& status) const
{
return (this == &when ||
getTime(status) == when.getTime(status));
}
// -------------------------------------
bool_t
Calendar::before(const Calendar& when, UErrorCode& status) const
{
return (this != &when &&
getTimeInMillis(status) < when.getTimeInMillis(status));
}
// -------------------------------------
bool_t
Calendar::after(const Calendar& when, UErrorCode& status) const
{
return (this != &when &&
getTimeInMillis(status) > when.getTimeInMillis(status));
}
// {sfb} not in Java API, but looks similar to operator==
bool_t
Calendar::equivalentTo(const Calendar& other) const
{
// Return true if another Calendar object is equivalent to this one. An equivalent
// Calendar will behave exactly as this one does (i.e., it will have be the same subclass
// of Calendar, and have the same time zone, week-count values, and leniency level),
// but may be set to a different time.
return getDynamicClassID() == other.getDynamicClassID() &&
fLenient == other.fLenient &&
fFirstDayOfWeek == other.fFirstDayOfWeek &&
fMinimalDaysInFirstWeek == other.fMinimalDaysInFirstWeek &&
*fZone == *other.fZone;
}
// -------------------------------------
const Locale*
Calendar::getAvailableLocales(int32_t& count)
{
return Locale::getAvailableLocales(count);
}
// -------------------------------------
UDate
Calendar::getNow()
{
return (UDate)icu_getUTCtime() * kMillisPerSecond; // return as milliseconds
}
// -------------------------------------
/**
* Gets this Calendar's current time as a long.
* @return the current time as UTC milliseconds from the epoch.
*/
double
Calendar::getTimeInMillis(UErrorCode& status) const
{
if(FAILURE(status))
return 0.0;
if ( ! fIsTimeSet)
((Calendar*)this)->updateTime(status);
return fTime;
}
// -------------------------------------
/**
* Sets this Calendar's current time from the given long value.
* @param date the new time in UTC milliseconds from the epoch.
*/
void
Calendar::setTimeInMillis( double millis, UErrorCode& status ) {
if(FAILURE(status))
return;
fIsTimeSet = TRUE;
fTime = millis;
fAreFieldsSet = FALSE;
computeFields(status);
fAreFieldsSet = TRUE;
fAreAllFieldsSet = TRUE;
}
// -------------------------------------
int32_t
Calendar::get(EDateFields field, UErrorCode& status) const
{
// field values are only computed when actually requested; for more on when computation
// of various things happens, see the "data flow in Calendar" description at the top
// of this file
if (SUCCESS(status)) ((Calendar*)this)->complete(status); // Cast away const
return SUCCESS(status) ? fFields[field] : 0;
}
// -------------------------------------
void
Calendar::set(EDateFields field, int32_t value)
{
fIsTimeSet = FALSE;
fFields[field] = value;
fStamp[field] = fNextStamp++;
fAreFieldsSet = FALSE;
fIsSet[field] = TRUE; // Remove later
}
// -------------------------------------
void
Calendar::set(int32_t year, int32_t month, int32_t date)
{
set(YEAR, year);
set(MONTH, month);
set(DATE, date);
}
// -------------------------------------
void
Calendar::set(int32_t year, int32_t month, int32_t date, int32_t hour, int32_t minute)
{
set(YEAR, year);
set(MONTH, month);
set(DATE, date);
set(HOUR_OF_DAY, hour);
set(MINUTE, minute);
}
// -------------------------------------
void
Calendar::set(int32_t year, int32_t month, int32_t date, int32_t hour, int32_t minute, int32_t second)
{
set(YEAR, year);
set(MONTH, month);
set(DATE, date);
set(HOUR_OF_DAY, hour);
set(MINUTE, minute);
set(SECOND, second);
}
// -------------------------------------
void
Calendar::clear()
{
for (int32_t i=0; i<FIELD_COUNT; ++i) {
fFields[i] = 0; // Must do this; other code depends on it
fIsSet[i] = FALSE;
fStamp[i] = kUnset;
}
fAreFieldsSet = FALSE;
fAreAllFieldsSet = FALSE;
fIsTimeSet = FALSE;
}
// -------------------------------------
void
Calendar::clear(EDateFields field)
{
fFields[field] = 0;
fStamp[field] = kUnset;
fAreFieldsSet = FALSE;
fAreAllFieldsSet = FALSE;
fIsSet[field] = FALSE; // Remove later
fIsTimeSet = FALSE;
}
// -------------------------------------
bool_t
Calendar::isSet(EDateFields field) const
{
return fStamp[field] != kUnset;
}
// -------------------------------------
void
Calendar::complete(UErrorCode& status)
{
if (!fIsTimeSet)
updateTime(status);
if (!fAreFieldsSet) {
computeFields(status); // fills in unset fields
fAreFieldsSet = TRUE;
fAreAllFieldsSet = TRUE;
}
}
// -------------------------------------
void
Calendar::adoptTimeZone(TimeZone* zone)
{
// Do nothing if passed-in zone is NULL
if (zone == NULL) return;
// fZone should always be non-null
if (fZone != NULL) delete fZone;
fZone = zone;
// if the zone changes, we need to recompute the time fields
fAreFieldsSet = FALSE;
}
// -------------------------------------
void
Calendar::setTimeZone(const TimeZone& zone)
{
adoptTimeZone(zone.clone());
}
// -------------------------------------
const TimeZone&
Calendar::getTimeZone() const
{
return *fZone;
}
// -------------------------------------
TimeZone*
Calendar::orphanTimeZone()
{
TimeZone *z = fZone;
// we let go of the time zone; the new time zone is the system default time zone
fZone = TimeZone::createDefault();
return z;
}
// -------------------------------------
void
Calendar::setLenient(bool_t lenient)
{
fLenient = lenient;
}
// -------------------------------------
bool_t
Calendar::isLenient() const
{
return fLenient;
}
// -------------------------------------
void
Calendar::setFirstDayOfWeek(EDaysOfWeek value)
{
fFirstDayOfWeek = value;
}
// -------------------------------------
Calendar::EDaysOfWeek
Calendar::getFirstDayOfWeek() const
{
return fFirstDayOfWeek;
}
// -------------------------------------
void
Calendar::setMinimalDaysInFirstWeek(uint8_t value)
{
fMinimalDaysInFirstWeek = value;
}
// -------------------------------------
uint8_t
Calendar::getMinimalDaysInFirstWeek() const
{
return fMinimalDaysInFirstWeek;
}
// -------------------------------------
int32_t
Calendar::getActualMinimum(EDateFields field, UErrorCode& status) const
{
int32_t fieldValue = getGreatestMinimum(field);
int32_t endValue = getMinimum(field);
// if we know that the minimum value is always the same, just return it
if (fieldValue == endValue) {
return fieldValue;
}
// clone the calendar so we don't mess with the real one, and set it to
// accept anything for the field values
Calendar *work = (Calendar*)this->clone();
work->setLenient(TRUE);
// now try each value from getLeastMaximum() to getMaximum() one by one until
// we get a value that normalizes to another value. The last value that
// normalizes to itself is the actual minimum for the current date
int32_t result = fieldValue;
do {
work->set(field, fieldValue);
if (work->get(field, status) != fieldValue) {
break;
}
else {
result = fieldValue;
fieldValue--;
}
} while (fieldValue >= endValue);
delete work;
return result;
}
// -------------------------------------
int32_t
Calendar::getActualMaximum(EDateFields field, UErrorCode& status) const
{
int32_t fieldValue = getLeastMaximum(field);
int32_t endValue = getMaximum(field);
// if we know that the maximum value is always the same, just return it
if (fieldValue == endValue) {
return fieldValue;
}
// clone the calendar so we don't mess with the real one, and set it to
// accept anything for the field values
Calendar *work = (Calendar*)this->clone();
work->setLenient(TRUE);
// if we're counting weeks, set the day of the week to Sunday. We know the
// last week of a month or year will contain the first day of the week.
if (field == WEEK_OF_YEAR || field == WEEK_OF_MONTH)
work->set(DAY_OF_WEEK, fFirstDayOfWeek);
// now try each value from getLeastMaximum() to getMaximum() one by one until
// we get a value that normalizes to another value. The last value that
// normalizes to itself is the actual maximum for the current date
int32_t result = fieldValue;
do {
work->set(field, fieldValue);
if(work->get(field, status) != fieldValue) {
break;
}
else {
result = fieldValue;
fieldValue++;
}
} while (fieldValue <= endValue);
delete work;
return result;
}
// -------------------------------------
int32_t Calendar::stringToDayNumber(const UnicodeString& string, UErrorCode& status)
{
// Convert a UnicodeString to a long integer, using the standard C library.
// Return both the value obtained, and a UErrorCode indicating success or failure.
// We fail if the string is zero length, of if strtol() does not parse all
// of the characters in the string, or if the value is not in the range
// 1..7. (This is used to read the week-count data from the resource files;
// ResourceBundle returns all data in string form, so we have to convert it here.)
if (FAILURE(status)) return 0;
int32_t len = string.size();
char *number = new char[1 + len];
if (number == 0) { status = MEMORY_ALLOCATION_ERROR; return 0; }
char *end;
string.extract(0, len, number);
number[len] = 0;
int32_t value = strtol(number, &end, 10); // Radix 10
delete[] number;
if (end-number != len || len == 0 || value < 1 || value > 7)
status = INVALID_FORMAT_ERROR;
return value;
}
// -------------------------------------
void
Calendar::setWeekCountData(const Locale& desiredLocale, UErrorCode& status)
{
// Read the week count data from the resource bundle. This should
// have the form:
//
// DateTimeElements {
// "1", // first day of week
// "1" // min days in week
// }
const UnicodeString *dateTimeElements;
int32_t count;
if (FAILURE(status)) return;
ResourceBundle resource(Locale::getDataDirectory(), desiredLocale, status);
// If the resource data doesn't seem to be present at all, then use last-resort
// hard-coded data.
if (FAILURE(status))
{
status = USING_FALLBACK_ERROR;
fFirstDayOfWeek = Calendar::SUNDAY;
fMinimalDaysInFirstWeek = 1;
return;
}
dateTimeElements = resource.getStringArray(kDateTimeElements, count, status);
if (FAILURE(status)) return;
if (count != 2)
{
status = INVALID_FORMAT_ERROR;
return;
}
fFirstDayOfWeek = (Calendar::EDaysOfWeek)stringToDayNumber(dateTimeElements[0], status);
fMinimalDaysInFirstWeek = (uint8_t)stringToDayNumber(dateTimeElements[1], status);
}
/**
* Recompute the time and update the status fields isTimeSet
* and areFieldsSet. Callers should check isTimeSet and only
* call this method if isTimeSet is false.
*/
void
Calendar::updateTime(UErrorCode& status)
{
computeTime(status);
if(FAILURE(status))
return;
// If we are lenient, we need to recompute the fields to normalize
// the values. Also, if we haven't set all the fields yet (i.e.,
// in a newly-created object), we need to fill in the fields. [LIU]
if (isLenient() || ! fAreAllFieldsSet)
fAreFieldsSet = FALSE;
fIsTimeSet = TRUE;
}
//eof