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The Labs \ Source Viewer \ SSCLI \ System.Globalization \ JapaneseCalendar

SSCLI

// ==++==
//
//
//
// The use and distribution terms for this software are contained in the file
// named license.txt, which can be found in the root of this distribution.
// By using this software in any fashion, you are agreeing to be bound by the
// terms of this license.
//
// You must not remove this notice, or any other, from this software.
//
//
// ==--==
namespace System.Globalization
{
using System;
/*=================================JapaneseCalendar==========================
**
** JapaneseCalendar is based on Gregorian calendar. The month and day values are the same as
** Gregorian calendar. However, the year value is an offset to the Gregorian
** year based on the era.
**
** This system is adopted by Emperor Meiji in 1868. The year value is counted based on the reign of an emperor,
** and the era begins on the day an emperor ascends the throne and continues until his death.
** The era changes at 12:00AM.
**
** For example, the current era is Heisei. It started on 1989/1/8 A.D. Therefore, Gregorian year 1989 is also Heisei 1st.
** 1989/1/8 A.D. is also Heisei 1st 1/8.
**
** Any date in the year during which era is changed can be reckoned in either era. For example,
** 1989/1/1 can be 1/1 Heisei 1st year or 1/1 Showa 64th year.
**
** Note:
** The DateTime can be represented by the JapaneseCalendar are limited to two factors:
** 1. The min value and max value of DateTime class.
** 2. The available era information.
**
** Calendar support range:
** Calendar Minimum Maximum
** ========== ========== ==========
** Gregorian 1868/09/08 9999/12/31
** Japanese Meiji 01/01 Heisei 8011/12/31
============================================================================*/
[Serializable()]
[System.Runtime.InteropServices.ComVisible(true)]
public class JapaneseCalendar : Calendar
{
static internal readonly DateTime calendarMinValue = new DateTime(1868, 9, 8);
[System.Runtime.InteropServices.ComVisible(false)]
public override DateTime MinSupportedDateTime {
get { return (calendarMinValue); }
}
[System.Runtime.InteropServices.ComVisible(false)]
public override DateTime MaxSupportedDateTime {
get { return (DateTime.MaxValue); }
}
// Return the type of the Japanese calendar.
//
[System.Runtime.InteropServices.ComVisible(false)]
public override CalendarAlgorithmType AlgorithmType {
get { return CalendarAlgorithmType.SolarCalendar; }
}
// m_EraInfo must be listed in reverse chronological order. The most recent era
// should be the first element.
// That is, m_EraInfo[0] contains the most recent era.
static internal EraInfo[] m_EraInfo = GregorianCalendarHelper.InitEraInfo(Calendar.CAL_JAPAN);
// The era value of the current era.
static internal Calendar m_defaultInstance;
internal GregorianCalendarHelper helper;
/*=================================GetDefaultInstance==========================
**Action: Internal method to provide a default intance of JapaneseCalendar. Used by NLS+ implementation
** and other calendars.
**Returns:
**Arguments:
**Exceptions:
============================================================================*/
static internal Calendar GetDefaultInstance()
{
if (m_defaultInstance == null) {
m_defaultInstance = new JapaneseCalendar();
}
return (m_defaultInstance);
}
public JapaneseCalendar()
{
helper = new GregorianCalendarHelper(this, m_EraInfo);
}
internal override int ID {
get { return (CAL_JAPAN); }
}
public override DateTime AddMonths(DateTime time, int months)
{
return (helper.AddMonths(time, months));
}
public override DateTime AddYears(DateTime time, int years)
{
return (helper.AddYears(time, years));
}
/*=================================GetDaysInMonth==========================
**Action: Returns the number of days in the month given by the year and month arguments.
**Returns: The number of days in the given month.
**Arguments:
** year The year in Japanese calendar.
** month The month
** era The Japanese era value.
**Exceptions
** ArgumentException If month is less than 1 or greater * than 12.
============================================================================*/
public override int GetDaysInMonth(int year, int month, int era)
{
return (helper.GetDaysInMonth(year, month, era));
}
public override int GetDaysInYear(int year, int era)
{
return (helper.GetDaysInYear(year, era));
}
public override int GetDayOfMonth(DateTime time)
{
return (helper.GetDayOfMonth(time));
}
public override DayOfWeek GetDayOfWeek(DateTime time)
{
return (helper.GetDayOfWeek(time));
}
public override int GetDayOfYear(DateTime time)
{
return (helper.GetDayOfYear(time));
}
public override int GetMonthsInYear(int year, int era)
{
return (helper.GetMonthsInYear(year, era));
}
[System.Runtime.InteropServices.ComVisible(false)]
public override int GetWeekOfYear(DateTime time, CalendarWeekRule rule, DayOfWeek firstDayOfWeek)
{
return (helper.GetWeekOfYear(time, rule, firstDayOfWeek));
}
/*=================================GetEra==========================
**Action: Get the era value of the specified time.
**Returns: The era value for the specified time.
**Arguments:
** time the specified date time.
**Exceptions: ArgumentOutOfRangeException if time is out of the valid era ranges.
============================================================================*/
public override int GetEra(DateTime time)
{
return (helper.GetEra(time));
}
public override int GetMonth(DateTime time)
{
return (helper.GetMonth(time));
}
public override int GetYear(DateTime time)
{
return (helper.GetYear(time));
}
public override bool IsLeapDay(int year, int month, int day, int era)
{
return (helper.IsLeapDay(year, month, day, era));
}
public override bool IsLeapYear(int year, int era)
{
return (helper.IsLeapYear(year, era));
}
// Returns the leap month in a calendar year of the specified era. This method returns 0
// if this calendar does not have leap month, or this year is not a leap year.
//
[System.Runtime.InteropServices.ComVisible(false)]
public override int GetLeapMonth(int year, int era)
{
return (helper.GetLeapMonth(year, era));
}
public override bool IsLeapMonth(int year, int month, int era)
{
return (helper.IsLeapMonth(year, month, era));
}
public override DateTime ToDateTime(int year, int month, int day, int hour, int minute, int second, int millisecond, int era)
{
return (helper.ToDateTime(year, month, day, hour, minute, second, millisecond, era));
}
// For Japanese calendar, four digit year is not used. Few emperors will live for more than one hundred years.
// Therefore, for any two digit number, we just return the original number.
public override int ToFourDigitYear(int year)
{
if (year <= 0) {
throw new ArgumentOutOfRangeException("year", Environment.GetResourceString("ArgumentOutOfRange_NeedPosNum"));
}
if (year > helper.MaxYear) {
throw new ArgumentOutOfRangeException("year", String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("ArgumentOutOfRange_Range"), 1, helper.MaxYear));
}
return (year);
}
public override int[] Eras {
get { return (helper.Eras); }
}
private const int DEFAULT_TWO_DIGIT_YEAR_MAX = 99;
internal override bool IsValidYear(int year, int era)
{
return helper.IsValidYear(year, era);
}
public override int TwoDigitYearMax {
get {
if (twoDigitYearMax == -1) {
twoDigitYearMax = GetSystemTwoDigitYearSetting(ID, DEFAULT_TWO_DIGIT_YEAR_MAX);
}
return (twoDigitYearMax);
}
set {
VerifyWritable();
if (value < 99 || value > helper.MaxYear) {
throw new ArgumentOutOfRangeException("year", String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("ArgumentOutOfRange_Range"), 99, helper.MaxYear));
}
twoDigitYearMax = value;
}
}
}
}