We need you! We're working hard on the next version of Developer Fusion - Let us know what you think we should be up to!

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

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;
using System.Runtime.Versioning;
using System.Text;
using Microsoft.Win32;
////////////////////////////////////////////////////////////////////////////
//
// Rules for the Hijri calendar:
// - The Hijri calendar is a strictly Lunar calendar.
// - Days begin at sunset.
// - Islamic Year 1 (Muharram 1, 1 A.H.) is equivalent to absolute date
// 227015 (Friday, July 16, 622 C.E. - Julian).
// - Leap Years occur in the 2, 5, 7, 10, 13, 16, 18, 21, 24, 26, & 29th
// years of a 30-year cycle. Year = leap iff ((11y+14) mod 30 < 11).
// - There are 12 months which contain alternately 30 and 29 days.
// - The 12th month, Dhu al-Hijjah, contains 30 days instead of 29 days
// in a leap year.
// - Common years have 354 days. Leap years have 355 days.
// - There are 10,631 days in a 30-year cycle.
// - The Islamic months are:
// 1. Muharram (30 days) 7. Rajab (30 days)
// 2. Safar (29 days) 8. Sha'ban (29 days)
// 3. Rabi I (30 days) 9. Ramadan (30 days)
// 4. Rabi II (29 days) 10. Shawwal (29 days)
// 5. Jumada I (30 days) 11. Dhu al-Qada (30 days)
// 6. Jumada II (29 days) 12. Dhu al-Hijjah (29 days) {30}
//
// NOTENOTE
// The calculation of the HijriCalendar is based on the absolute date. And the
// absolute date means the number of days from January 1st, 1 A.D.
// Therefore, we do not support the days before the January 1st, 1 A.D.
//
//////////////////////////////////////////////////////////////////////////// </STRIP>
/*
** Calendar support range:
** Calendar Minimum Maximum
** ========== ========== ==========
** Gregorian 0622/07/18 9999/12/31
** Hijri 0001/01/01 9666/04/03
*/
[Serializable()]
[System.Runtime.InteropServices.ComVisible(true)]
public class HijriCalendar : Calendar
{
public static readonly int HijriEra = 1;
internal const int DatePartYear = 0;
internal const int DatePartDayOfYear = 1;
internal const int DatePartMonth = 2;
internal const int DatePartDay = 3;
internal const int MinAdvancedHijri = -2;
internal const int MaxAdvancedHijri = 2;
static internal readonly int[] HijriMonthDays = {0, 30, 59, 89, 118, 148, 177, 207, 236, 266,
295, 325, 355};
//internal static Calendar m_defaultInstance;
private static string m_HijriAdvanceRegKeyEntry = "AddHijriDate";
private int m_HijriAdvance = Int32.MinValue;
// DateTime.MaxValue = Hijri calendar (year:9666, month: 4, day: 3).
internal const int MaxCalendarYear = 9666;
internal const int MaxCalendarMonth = 4;
internal const int MaxCalendarDay = 3;
// Hijri calendar (year: 1, month: 1, day:1 ) = Gregorian (year: 622, month: 7, day: 18)
// This is the minimal Gregorian date that we support in the HijriCalendar.
static internal readonly DateTime calendarMinValue = new DateTime(622, 7, 18);
static internal readonly DateTime calendarMaxValue = DateTime.MaxValue;
[System.Runtime.InteropServices.ComVisible(false)]
public override DateTime MinSupportedDateTime {
get { return (calendarMinValue); }
}
[System.Runtime.InteropServices.ComVisible(false)]
public override DateTime MaxSupportedDateTime {
get { return (calendarMaxValue); }
}
// Return the type of the Hijri calendar.
//
[System.Runtime.InteropServices.ComVisible(false)]
public override CalendarAlgorithmType AlgorithmType {
get { return CalendarAlgorithmType.LunarCalendar; }
}
/*=================================GetDefaultInstance==========================
**Action: Internal method to provide a default intance of HijriCalendar. Used by NLS+ implementation
** and other calendars.
**Returns:
**Arguments:
**Exceptions:
============================================================================*/
/*
internal static Calendar GetDefaultInstance() {
if (m_defaultInstance == null) {
m_defaultInstance = new HijriCalendar();
}
return (m_defaultInstance);
}
*/
// Construct an instance of Hijri calendar.
public HijriCalendar()
{
}
internal override int ID {
get { return (CAL_HIJRI); }
}
/*=================================GetAbsoluteDateHijri==========================
**Action: Gets the Absolute date for the given Hijri date. The absolute date means
** the number of days from January 1st, 1 A.D.
**Returns:
**Arguments:
**Exceptions:
============================================================================*/
long GetAbsoluteDateHijri(int y, int m, int d)
{
return (long)(DaysUpToHijriYear(y) + HijriMonthDays[m - 1] + d - 1 - HijriAdjustment);
}
/*=================================DaysUpToHijriYear==========================
**Action: Gets the total number of days (absolute date) up to the given Hijri Year.
** The absolute date means the number of days from January 1st, 1 A.D.
**Returns: Gets the total number of days (absolute date) up to the given Hijri Year.
**Arguments: HijriYear year value in Hijri calendar.
**Exceptions: None
**Notes:
============================================================================*/
long DaysUpToHijriYear(int HijriYear)
{
long NumDays;
// number of absolute days
int NumYear30;
// number of years up to current 30 year cycle
int NumYearsLeft;
// number of years into 30 year cycle
//
// Compute the number of years up to the current 30 year cycle.
//
NumYear30 = ((HijriYear - 1) / 30) * 30;
//
// Compute the number of years left. This is the number of years
// into the 30 year cycle for the given year.
//
NumYearsLeft = HijriYear - NumYear30 - 1;
//
// Compute the number of absolute days up to the given year.
//
NumDays = ((NumYear30 * 10631l) / 30l) + 227013l;
while (NumYearsLeft > 0) {
// Common year is 354 days, and leap year is 355 days.
NumDays += 354 + (IsLeapYear(NumYearsLeft, CurrentEra) ? 1 : 0);
NumYearsLeft--;
}
//
// Return the number of absolute days.
//
return (NumDays);
}
public int HijriAdjustment {
get {
if (m_HijriAdvance == Int32.MinValue) {
// Never been set before. Use the system value from registry.
m_HijriAdvance = GetAdvanceHijriDate();
}
return (m_HijriAdvance);
}
set {
VerifyWritable();
// NOTE: Check the value of Min/MaxAdavncedHijri with Arabic speakers to see if the assumption is good.
if (value < MinAdvancedHijri || value > MaxAdvancedHijri) {
throw new ArgumentOutOfRangeException("HijriAdjustment", String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("ArgumentOutOfRange_Bounds_Lower_Upper"), MinAdvancedHijri, MaxAdvancedHijri));
}
m_HijriAdvance = value;
}
}
/*=================================GetAdvanceHijriDate==========================
**Action: Gets the AddHijriDate value from the registry.
**Returns:
**Arguments: None.
**Exceptions:
**Note:
** The HijriCalendar has a user-overidable calculation. That is, use can set a value from the control
** panel, so that the calculation of the Hijri Calendar can move ahead or backwards from -2 to +2 days.
**
** The valid string values in the registry are:
** "AddHijriDate-2" => Add -2 days to the current calculated Hijri date.
** "AddHijriDate" => Add -1 day to the current calculated Hijri date.
** "" => Add 0 day to the current calculated Hijri date.
** "AddHijriDate+1" => Add +1 days to the current calculated Hijri date.
** "AddHijriDate+2" => Add +2 days to the current calculated Hijri date.
============================================================================*/
[ResourceExposure(ResourceScope.None)]
[ResourceConsumption(ResourceScope.Machine, ResourceScope.Machine)]
int GetAdvanceHijriDate()
{
int hijriAdvance = 0;
const int parameterValueLength = 255;
StringBuilder parameterValue = new StringBuilder(parameterValueLength);
bool rc = Win32Native.FetchConfigurationString(true, m_HijriAdvanceRegKeyEntry, parameterValue, parameterValueLength);
if (rc) {
string str = parameterValue.ToString();
if (String.Compare(str, 0, m_HijriAdvanceRegKeyEntry, 0, m_HijriAdvanceRegKeyEntry.Length, true, CultureInfo.InvariantCulture) == 0) {
if (str.Length == m_HijriAdvanceRegKeyEntry.Length)
hijriAdvance = -1;
else {
str = str.Substring(m_HijriAdvanceRegKeyEntry.Length);
try {
int advance = Int32.Parse(str.ToString(), CultureInfo.InvariantCulture);
if ((advance >= MinAdvancedHijri) && (advance <= MaxAdvancedHijri)) {
hijriAdvance = advance;
}
}
// If we got garbage from registry just ignore it.
// hijriAdvance = 0 because of declaraction assignment up above.
catch (ArgumentException) {
}
catch (FormatException) {
}
catch (OverflowException) {
}
}
}
}
return (hijriAdvance);
}
internal void CheckTicksRange(long ticks)
{
if (ticks < calendarMinValue.Ticks || ticks > calendarMaxValue.Ticks) {
throw new ArgumentOutOfRangeException("time", String.Format(CultureInfo.InvariantCulture, Environment.GetResourceString("ArgumentOutOfRange_CalendarRange"), calendarMinValue, calendarMaxValue));
}
}
internal void CheckEraRange(int era)
{
if (era != CurrentEra && era != HijriEra) {
throw new ArgumentOutOfRangeException("era", Environment.GetResourceString("ArgumentOutOfRange_InvalidEraValue"));
}
}
internal void CheckYearRange(int year, int era)
{
CheckEraRange(era);
if (year < 1 || year > MaxCalendarYear) {
throw new ArgumentOutOfRangeException("year", String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("ArgumentOutOfRange_Range"), 1, MaxCalendarYear));
}
}
internal void CheckYearMonthRange(int year, int month, int era)
{
CheckYearRange(year, era);
if (year == MaxCalendarYear) {
if (month > MaxCalendarMonth) {
throw new ArgumentOutOfRangeException("month", String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("ArgumentOutOfRange_Range"), 1, MaxCalendarMonth));
}
}
if (month < 1 || month > 12) {
throw new ArgumentOutOfRangeException("month", Environment.GetResourceString("ArgumentOutOfRange_Month"));
}
}
/*=================================GetDatePart==========================
**Action: Returns a given date part of this <i>DateTime</i>. This method is used
** to compute the year, day-of-year, month, or day part.
**Returns:
**Arguments:
**Exceptions: ArgumentException if part is incorrect.
**Notes:
** First, we get the absolute date (the number of days from January 1st, 1 A.C) for the given ticks.
** Use the formula (((AbsoluteDate - 227013) * 30) / 10631) + 1, we can a rough value for the Hijri year.
** In order to get the exact Hijri year, we compare the exact absolute date for HijriYear and (HijriYear + 1).
** From here, we can get the correct Hijri year.
============================================================================*/
internal virtual int GetDatePart(long ticks, int part)
{
int HijriYear;
// Hijri year
int HijriMonth;
// Hijri month
int HijriDay;
// Hijri day
long NumDays;
// The calculation buffer in number of days.
CheckTicksRange(ticks);
//
// Get the absolute date. The absolute date is the number of days from January 1st, 1 A.D.
// 1/1/0001 is absolute date 1.
//
NumDays = ticks / GregorianCalendar.TicksPerDay + 1;
//
// See how much we need to backup or advance
//
NumDays += HijriAdjustment;
//
// Calculate the appromixate Hijri Year from this magic formula.
//
HijriYear = (int)(((NumDays - 227013) * 30) / 10631) + 1;
long daysToHijriYear = DaysUpToHijriYear(HijriYear);
// The absoulte date for HijriYear
long daysOfHijriYear = GetDaysInYear(HijriYear, CurrentEra);
// The number of days for (HijriYear+1) year.
if (NumDays < daysToHijriYear) {
daysToHijriYear -= daysOfHijriYear;
HijriYear--;
}
else if (NumDays == daysToHijriYear) {
HijriYear--;
daysToHijriYear -= GetDaysInYear(HijriYear, CurrentEra);
}
else {
if (NumDays > daysToHijriYear + daysOfHijriYear) {
daysToHijriYear += daysOfHijriYear;
HijriYear++;
}
}
if (part == DatePartYear) {
return (HijriYear);
}
//
// Calculate the Hijri Month.
//
HijriMonth = 1;
NumDays -= daysToHijriYear;
if (part == DatePartDayOfYear) {
return ((int)NumDays);
}
while ((HijriMonth <= 12) && (NumDays > HijriMonthDays[HijriMonth - 1])) {
HijriMonth++;
}
HijriMonth--;
if (part == DatePartMonth) {
return (HijriMonth);
}
//
// Calculate the Hijri Day.
//
HijriDay = (int)(NumDays - HijriMonthDays[HijriMonth - 1]);
if (part == DatePartDay) {
return (HijriDay);
}
// Incorrect part value.
throw new InvalidOperationException(Environment.GetResourceString("InvalidOperation_DateTimeParsing"));
}
// Returns the DateTime resulting from adding the given number of
// months to the specified DateTime. The result is computed by incrementing
// (or decrementing) the year and month parts of the specified DateTime by
// value months, and, if required, adjusting the day part of the
// resulting date downwards to the last day of the resulting month in the
// resulting year. The time-of-day part of the result is the same as the
// time-of-day part of the specified DateTime.
//
// In more precise terms, considering the specified DateTime to be of the
// form y / m / d + t, where y is the
// year, m is the month, d is the day, and t is the
// time-of-day, the result is y1 / m1 / d1 + t,
// where y1 and m1 are computed by adding value months
// to y and m, and d1 is the largest value less than
// or equal to d that denotes a valid day in month m1 of year
// y1.
//
public override DateTime AddMonths(DateTime time, int months)
{
if (months < -120000 || months > 120000) {
throw new ArgumentOutOfRangeException("months", String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("ArgumentOutOfRange_Range"), -120000, 120000));
}
// Get the date in Hijri calendar.
int y = GetDatePart(time.Ticks, DatePartYear);
int m = GetDatePart(time.Ticks, DatePartMonth);
int d = GetDatePart(time.Ticks, DatePartDay);
int i = m - 1 + months;
if (i >= 0) {
m = i % 12 + 1;
y = y + i / 12;
}
else {
m = 12 + (i + 1) % 12;
y = y + (i - 11) / 12;
}
int days = GetDaysInMonth(y, m);
if (d > days) {
d = days;
}
long ticks = GetAbsoluteDateHijri(y, m, d) * TicksPerDay + (time.Ticks % TicksPerDay);
Calendar.CheckAddResult(ticks, MinSupportedDateTime, MaxSupportedDateTime);
return (new DateTime(ticks));
}
// Returns the DateTime resulting from adding the given number of
// years to the specified DateTime. The result is computed by incrementing
// (or decrementing) the year part of the specified DateTime by value
// years. If the month and day of the specified DateTime is 2/29, and if the
// resulting year is not a leap year, the month and day of the resulting
// DateTime becomes 2/28. Otherwise, the month, day, and time-of-day
// parts of the result are the same as those of the specified DateTime.
//
public override DateTime AddYears(DateTime time, int years)
{
return (AddMonths(time, years * 12));
}
// Returns the day-of-month part of the specified DateTime. The returned
// value is an integer between 1 and 31.
//
public override int GetDayOfMonth(DateTime time)
{
return (GetDatePart(time.Ticks, DatePartDay));
}
// Returns the day-of-week part of the specified DateTime. The returned value
// is an integer between 0 and 6, where 0 indicates Sunday, 1 indicates
// Monday, 2 indicates Tuesday, 3 indicates Wednesday, 4 indicates
// Thursday, 5 indicates Friday, and 6 indicates Saturday.
//
public override DayOfWeek GetDayOfWeek(DateTime time)
{
return ((DayOfWeek)((int)(time.Ticks / TicksPerDay + 1) % 7));
}
// Returns the day-of-year part of the specified DateTime. The returned value
// is an integer between 1 and 366.
//
public override int GetDayOfYear(DateTime time)
{
return (GetDatePart(time.Ticks, DatePartDayOfYear));
}
// Returns the number of days in the month given by the year and
// month arguments.
//
public override int GetDaysInMonth(int year, int month, int era)
{
CheckYearMonthRange(year, month, era);
if (month == 12) {
// For the 12th month, leap year has 30 days, and common year has 29 days.
return (IsLeapYear(year, CurrentEra) ? 30 : 29);
}
// Other months contain 30 and 29 days alternatively. The 1st month has 30 days.
return (((month % 2) == 1) ? 30 : 29);
}
// Returns the number of days in the year given by the year argument for the current era.
//
public override int GetDaysInYear(int year, int era)
{
CheckYearRange(year, era);
// Common years have 354 days. Leap years have 355 days.
return (IsLeapYear(year, CurrentEra) ? 355 : 354);
}
// Returns the era for the specified DateTime value.
public override int GetEra(DateTime time)
{
CheckTicksRange(time.Ticks);
return (HijriEra);
}
public override int[] Eras {
get { return (new int[] {HijriEra}); }
}
// Returns the month part of the specified DateTime. The returned value is an
// integer between 1 and 12.
//
public override int GetMonth(DateTime time)
{
return (GetDatePart(time.Ticks, DatePartMonth));
}
// Returns the number of months in the specified year and era.
public override int GetMonthsInYear(int year, int era)
{
CheckYearRange(year, era);
return (12);
}
// Returns the year part of the specified DateTime. The returned value is an
// integer between 1 and MaxCalendarYear.
//
public override int GetYear(DateTime time)
{
return (GetDatePart(time.Ticks, DatePartYear));
}
// Checks whether a given day in the specified era is a leap day. This method returns true if
// the date is a leap day, or false if not.
//
public override bool IsLeapDay(int year, int month, int day, int era)
{
// The year/month/era value checking is done in GetDaysInMonth().
int daysInMonth = GetDaysInMonth(year, month, era);
if (day < 1 || day > daysInMonth) {
throw new ArgumentOutOfRangeException("day", String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("ArgumentOutOfRange_Day"), daysInMonth, month));
}
return (IsLeapYear(year, era) && month == 12 && day == 30);
}
// 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)
{
CheckYearRange(year, era);
return (0);
}
// Checks whether a given month in the specified era is a leap month. This method returns true if
// month is a leap month, or false if not.
//
public override bool IsLeapMonth(int year, int month, int era)
{
CheckYearMonthRange(year, month, era);
return (false);
}
// Checks whether a given year in the specified era is a leap year. This method returns true if
// year is a leap year, or false if not.
//
public override bool IsLeapYear(int year, int era)
{
CheckYearRange(year, era);
return ((((year * 11) + 14) % 30) < 11);
}
// Returns the date and time converted to a DateTime value. Throws an exception if the n-tuple is invalid.
//
public override DateTime ToDateTime(int year, int month, int day, int hour, int minute, int second, int millisecond, int era)
{
// The year/month/era checking is done in GetDaysInMonth().
int daysInMonth = GetDaysInMonth(year, month, era);
if (day < 1 || day > daysInMonth) {
BCLDebug.Log("year = " + year + ", month = " + month + ", day = " + day);
throw new ArgumentOutOfRangeException("day", String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("ArgumentOutOfRange_Day"), daysInMonth, month));
}
long lDate = GetAbsoluteDateHijri(year, month, day);
if (lDate >= 0) {
return (new DateTime(lDate * GregorianCalendar.TicksPerDay + TimeToTicks(hour, minute, second, millisecond)));
}
else {
throw new ArgumentOutOfRangeException(null, Environment.GetResourceString("ArgumentOutOfRange_BadYearMonthDay"));
}
}
private const int DEFAULT_TWO_DIGIT_YEAR_MAX = 1451;
public override int TwoDigitYearMax {
get {
if (twoDigitYearMax == -1) {
twoDigitYearMax = GetSystemTwoDigitYearSetting(ID, DEFAULT_TWO_DIGIT_YEAR_MAX);
}
return (twoDigitYearMax);
}
set {
VerifyWritable();
if (value < 99 || value > MaxCalendarYear) {
throw new ArgumentOutOfRangeException("value", String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("ArgumentOutOfRange_Range"), 99, MaxCalendarYear));
}
twoDigitYearMax = value;
}
}
public override int ToFourDigitYear(int year)
{
if (year < 100) {
return (base.ToFourDigitYear(year));
}
if (year > MaxCalendarYear) {
throw new ArgumentOutOfRangeException("year", String.Format(CultureInfo.CurrentCulture, Environment.GetResourceString("ArgumentOutOfRange_Range"), 1, MaxCalendarYear));
}
return (year);
}
}
}