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com.trolltech.qt.core
Class QDate

java.lang.Object
  extended by com.trolltech.qt.QSignalEmitter
      extended by com.trolltech.qt.QtJambiObject
          extended by com.trolltech.qt.core.QDate
All Implemented Interfaces:
QtJambiInterface, java.lang.Comparable

public class QDate
extends QtJambiObject
implements java.lang.Comparable

The QDate class provides date functions.

A QDate object contains a calendar date, i.e. year, month, and day numbers, in the Gregorian calendar (Julian calendar for dates before 15 October 1582). It can read the current date from the system clock. It provides functions for comparing dates, and for manipulating dates. For example, it is possible to add and subtract days, months, and years to dates.

A QDate object is typically created either by giving the year, month, and day numbers explicitly, or by using the static function currentDate that creates a QDate object containing the system clock's date. An explicit date can also be set using setDate. The fromString function returns a QDate given a string and a date format which is used to interpret the date within the string.

The year, month, and day functions provide access to the year, month, and day numbers. Also, dayOfWeek and dayOfYear functions are provided. The same information is provided in textual format by the toString, shortDayName, longDayName, shortMonthName, and longMonthName functions.

QDate provides a full set of operators to compare two QDate objects where smaller means earlier, and larger means later.

You can increment (or decrement) a date by a given number of days using addDays. Similarly you can use addMonths and addYears. The daysTo function returns the number of days between two dates.

The daysInMonth and daysInYear functions return how many days there are in this date's month and year, respectively. The isLeapYear function indicates whether this date is in a leap year.

Note that the Gregorian calendar was introduced at different dates in different countries and regions. QDate uses the Gregorian calendar starting from 15 October 1582, and uses the Julian calendar for dates up to 4 October 1582.

See Also:
QTime, QDateTime, QDateEdit, QDateTimeEdit, QCalendarWidget

Nested Class Summary
 
Nested classes/interfaces inherited from class com.trolltech.qt.QSignalEmitter
QSignalEmitter.AbstractSignal, QSignalEmitter.Signal0, QSignalEmitter.Signal1<A>, QSignalEmitter.Signal2<A,B>, QSignalEmitter.Signal3<A,B,C>, QSignalEmitter.Signal4<A,B,C,D>, QSignalEmitter.Signal5<A,B,C,D,E>, QSignalEmitter.Signal6<A,B,C,D,E,F>, QSignalEmitter.Signal7<A,B,C,D,E,F,G>, QSignalEmitter.Signal8<A,B,C,D,E,F,G,H>, QSignalEmitter.Signal9<A,B,C,D,E,F,G,H,I>
 
Constructor Summary
QDate()
          Constructs a null date.
QDate(int y, int m, int d)
          Constructs a date with year y, month m and day d.
 
Method Summary
 QDate addDays(int days)
          Returns a QDate object containing a date days later than the date of this object (or earlier if days is negative).
 QDate addMonths(int months)
          Returns a QDate object containing a date months later than the date of this object (or earlier if months is negative).
 QDate addYears(int years)
          Returns a QDate object containing a date years later than the date of this object (or earlier if years is negative).
 int compareTo(java.lang.Object other)
          
static QDate currentDate()
          Returns the current date, as reported by the system clock.
 int day()
          Returns the day of the month (1 to 31) of this date.
 int dayOfWeek()
          Returns the weekday (1 to 7) for this date.
 int dayOfYear()
          Returns the day of the year (1 to 365) for this date.
 int daysInMonth()
          Returns the number of days in the month (28 to 31) for this date.
 int daysInYear()
          Returns the number of days in the year (365 or 366) for this date.
 int daysTo(QDate arg__1)
          Returns the number of days from this date to arg__1 (which is negative if arg__1 is earlier than this date).
 boolean equals(java.lang.Object other)
          
static QDate fromJulianDay(int jd)
          Converts the Julian day jd to a QDate.
static QDate fromNativePointer(QNativePointer nativePointer)
          This function returns the QDate instance pointed to by nativePointer
static QDate fromString(java.lang.String s)
          Equivalent to fromString(s, Qt::TextDate).
static QDate fromString(java.lang.String s, Qt.DateFormat f)
          Returns the QDate represented by the s, using the f given, or an invalid date if the string cannot be parsed.
static QDate fromString(java.lang.String s, java.lang.String format)
          Returns the QDate represented by the s, using the format given, or an invalid date if the string cannot be parsed.
static int gregorianToJulian(int y, int m, int d)
          
static boolean isLeapYear(int year)
          Returns true if the specified year is a leap year; otherwise returns false.
 boolean isNull()
          Returns true if the date is null; otherwise returns false.
 boolean isValid()
          Returns true if this date is valid; otherwise returns false.
static boolean isValid(int y, int m, int d)
          Returns true if the specified date (y, m, and d) is valid; otherwise returns false.
static java.lang.String longDayName(int weekday)
          Returns the long name of the weekday using the following convention:
static java.lang.String longMonthName(int month)
          Returns the long name of the month using the following convention:
 int month()
          Returns the number corresponding to the month of this date, using the following convention:
static QNativePointer nativePointerArray(QDate[] array)
          This function returns a QNativePointer that is pointing to the specified QDate array.
 void readFrom(QDataStream arg__1)
          Reads a QDate from arg__1.
 boolean setDate(int year, int month, int date)
          Sets the date's year, month, and date.
static java.lang.String shortDayName(int weekday)
          Returns the name of the weekday using the following convention:
static java.lang.String shortMonthName(int month)
          Returns the name of the month using the following convention:
 int toJulianDay()
          Converts the date to a Julian day.
 java.lang.String toString()
          Equivalent to toString(Qt::TextDate).
 java.lang.String toString(Qt.DateFormat f)
          Returns the date as a string.
 java.lang.String toString(java.lang.String format)
          Returns the date as a string.
 int weekNumber()
          Returns the week number (1 to 53).
 void writeTo(QDataStream arg__1)
          Writes thisQDate to arg__1.
 int year()
          Returns the year of this date.
 int yearOfWeekNumber()
          This function returns the year number of the QDate's current week.
 
Methods inherited from class com.trolltech.qt.QtJambiObject
dispose, disposed, finalize, reassignNativeResources, tr, tr, tr
 
Methods inherited from class com.trolltech.qt.QSignalEmitter
blockSignals, disconnect, disconnect, signalsBlocked, signalSender, thread
 
Methods inherited from class java.lang.Object
clone, getClass, hashCode, notify, notifyAll, wait, wait, wait
 
Methods inherited from interface com.trolltech.qt.QtJambiInterface
disableGarbageCollection, nativeId, nativePointer, reenableGarbageCollection, setJavaOwnership
 

Constructor Detail

QDate

public QDate()

Constructs a null date. Null dates are invalid.

See Also:
isNull, isValid

QDate

public QDate(int y,
             int m,
             int d)

Constructs a date with year y, month m and day d.

If the specified date is invalid, the date is not set and isValid returns false. Any date before 2 January 4713 B.C. is considered invalid.

Warning: Years 0 to 99 are interpreted as is. If you want to specify the year 2010, you must write 2010, not 10.

See Also:
isValid
Method Detail

addDays

public final QDate addDays(int days)

Returns a QDate object containing a date days later than the date of this object (or earlier if days is negative).

See Also:
addMonths, addYears, daysTo

addMonths

public final QDate addMonths(int months)

Returns a QDate object containing a date months later than the date of this object (or earlier if months is negative).

See Also:
addDays, addYears

addYears

public final QDate addYears(int years)

Returns a QDate object containing a date years later than the date of this object (or earlier if years is negative).

See Also:
addDays, addMonths

day

public final int day()

Returns the day of the month (1 to 31) of this date.

See Also:
year, month, dayOfWeek

dayOfWeek

public final int dayOfWeek()

Returns the weekday (1 to 7) for this date.

See Also:
day, dayOfYear, Qt::DayOfWeek

dayOfYear

public final int dayOfYear()

Returns the day of the year (1 to 365) for this date.

See Also:
day, dayOfWeek

daysInMonth

public final int daysInMonth()

Returns the number of days in the month (28 to 31) for this date.

See Also:
day, daysInYear

daysInYear

public final int daysInYear()

Returns the number of days in the year (365 or 366) for this date.

See Also:
day, daysInMonth

daysTo

public final int daysTo(QDate arg__1)

Returns the number of days from this date to arg__1 (which is negative if arg__1 is earlier than this date).

Example:

    QDate d1(1995, 5, 17);  // May 17, 1995
    QDate d2(1995, 5, 20);  // May 20, 1995
    d1.daysTo(d2);          // returns 3
    d2.daysTo(d1);          // returns -3

See Also:
addDays

isNull

public final boolean isNull()

Returns true if the date is null; otherwise returns false. A null date is invalid.

See Also:
isValid

isValid

public final boolean isValid()

Returns true if this date is valid; otherwise returns false.

See Also:
isNull

month

public final int month()

Returns the number corresponding to the month of this date, using the following convention:

See Also:
year, day

writeTo

public final void writeTo(QDataStream arg__1)
Writes thisQDate to arg__1.


readFrom

public final void readFrom(QDataStream arg__1)
Reads a QDate from arg__1.


setDate

public final boolean setDate(int year,
                             int month,
                             int date)

Sets the date's year, month, and date. Returns true if the date is valid; otherwise returns false.

If the specified date is invalid, the QDate object is set to be invalid. Any date before 2 January 4713 B.C. is considered invalid.

See Also:
isValid

toJulianDay

public final int toJulianDay()

Converts the date to a Julian day.

See Also:
fromJulianDay

toString

public final java.lang.String toString()

Equivalent to toString(Qt::TextDate).

Overrides:
toString in class java.lang.Object

toString

public final java.lang.String toString(Qt.DateFormat f)

Returns the date as a string. The f parameter determines the format of the string.

If the f is Qt::TextDate, the string is formatted in the default way. QDate::shortDayName() and QDate::shortMonthName() are used to generate the string, so the day and month names will be localized names. An example of this formatting is "Sat May 20 1995".

If the f is Qt::ISODate, the string format corresponds to the ISO 8601 extended specification for representations of dates and times, taking the form YYYY-MM-DD, where YYYY is the year, MM is the month of the year (between 01 and 12), and DD is the day of the month between 01 and 31.

If the f is Qt::LocalDate or Qt::SystemLocaleDate, the string format depends on the locale settings of the system. Identical to calling QLocale::system().toString(date, QLocale::ShortFormat). Qt::LocalDate has been deprecated, please use Qt::SystemLocaleDate instead.

If the f is Qt::LocaleDate, the string format depends on the default application locale. This is the locale set with QLocale::setDefault(), or the system locale if no default locale has been set. Identical to calling QLocale().toString(date, QLocale::ShortFormat);

If the datetime is invalid, an empty string will be returned.

Warning: The Qt::ISODate format is only valid for years in the range 0 to 9999. This restriction may apply to Qt::LocalDate as well, depending on the locale settings.

See Also:
shortDayName, shortMonthName

toString

public final java.lang.String toString(java.lang.String format)

Returns the date as a string. The format parameter determines the format of the result string.

These expressions may be used:

ExpressionOutput
dthe day as number without a leading zero (1 to31)
ddthe day as number with a leading zero (01 to 31)
dddthe abbreviated localized day name (e.g. 'Mon' to 'Sun'). Uses QDate::shortDayName().
ddddthe long localized day name (e.g. 'Qt::Monday' to 'Qt::Sunday'). Uses QDate::longDayName().
Mthe month as number without a leading zero (1-12)
MMthe month as number with a leading zero (01-12)
MMMthe abbreviated localized month name (e.g. 'Jan' to 'Dec'). Uses QDate::shortMonthName().
MMMMthe long localized month name (e.g. 'January' to 'December'). Uses QDate::longMonthName().
yythe year as two digit number (00 to 99)
yyyythe year as four digit number

All other input characters will be ignored. Any sequence of characters that are enclosed in singlequotes will be treated as text and not be used as an expression. Two consecutive singlequotes ("''") are replaced by a singlequote in the output.

Example format strings (assuming that the QDate is the 20 July 1969):

FormatResult
dd.MM.yyyy20.07.1969
ddd MMMM d yySun July 20 69
'The day is' ddddThe day is Sunday

If the datetime is invalid, an empty string will be returned.

Warning: This function is only valid for years in the range 0 to 9999.

See Also:
QDateTime::toString, QTime::toString

year

public final int year()

Returns the year of this date. Negative numbers indicate years before 1 A.D. = 1 C.E., such that year -44 is 44 B.C.

See Also:
month, day

currentDate

public static QDate currentDate()

Returns the current date, as reported by the system clock.

See Also:
QTime::currentTime, QDateTime::currentDateTime

fromJulianDay

public static QDate fromJulianDay(int jd)

Converts the Julian day jd to a QDate.

See Also:
toJulianDay

fromString

public static QDate fromString(java.lang.String s,
                               java.lang.String format)

Returns the QDate represented by the s, using the format given, or an invalid date if the string cannot be parsed.

These expressions may be used for the format:

ExpressionOutput
dThe day as a number without a leading zero (1 to 31)
ddThe day as a number with a leading zero (01 to 31)
dddThe abbreviated localized day name (e.g. 'Mon' to 'Sun'). Uses QDate::shortDayName().
ddddThe long localized day name (e.g. 'Monday' to 'Sunday'). Uses QDate::longDayName().
MThe month as a number without a leading zero (1 to 12)
MMThe month as a number with a leading zero (01 to 12)
MMMThe abbreviated localized month name (e.g. 'Jan' to 'Dec'). Uses QDate::shortMonthName().
MMMMThe long localized month name (e.g. 'January' to 'December'). Uses QDate::longMonthName().
yyThe year as two digit number (00 to 99)
yyyyThe year as four digit number

All other input characters will be treated as text. Any sequence of characters that are enclosed in single quotes will also be treated as text and will not be used as an expression. For example:

    QDate date = QDate::fromString("1MM12car2003", "d'MM'MMcaryyyy");
    // date is 1 December 2003

If the format is not satisfied, an invalid QDate is returned. The expressions that don't expect leading zeroes (d, M) will be greedy. This means that they will use two digits even if this will put them outside the accepted range of values and leaves too few digits for other sections. For example, the following format string could have meant January 30 but the M will grab two digits, resulting in an invalid date:

    QDate date = QDate::fromString("130", "Md"); // invalid

For any field that is not represented in the format the following defaults are used:

FieldDefault value
Year1900
Month1
Day1

The following examples demonstrate the default values:

    QDate::fromString("1.30", "M.d");           // January 30 1900
    QDate::fromString("20000110", "yyyyMMdd");  // January 10, 2000
    QDate::fromString("20000110", "yyyyMd");    // January 10, 2000

See Also:
QDateTime::fromString, QTime::fromString, QDate::toString, QDateTime::toString, QTime::toString

fromString

public static QDate fromString(java.lang.String s)

Equivalent to fromString(s, Qt::TextDate).


fromString

public static QDate fromString(java.lang.String s,
                               Qt.DateFormat f)

Returns the QDate represented by the s, using the f given, or an invalid date if the string cannot be parsed.

Note for Qt::TextDate: It is recommended that you use the English short month names (e.g. "Jan"). Although localized month names can also be used, they depend on the user's locale settings.

Warning: Qt::LocalDate cannot be used here.


gregorianToJulian

public static int gregorianToJulian(int y,
                                    int m,
                                    int d)


isLeapYear

public static boolean isLeapYear(int year)

Returns true if the specified year is a leap year; otherwise returns false.


isValid

public static boolean isValid(int y,
                              int m,
                              int d)

Returns true if the specified date (y, m, and d) is valid; otherwise returns false.

Example:

    QDate::isValid(2002, 5, 17);  // true
    QDate::isValid(2002, 2, 30);  // false (Feb 30 does not exist)
    QDate::isValid(2004, 2, 29);  // true (2004 is a leap year)
    QDate::isValid(2000, 2, 29);  // true (2000 is a leap year)
    QDate::isValid(2006, 2, 29);  // false (2006 is not a leap year)
    QDate::isValid(2100, 2, 29);  // false (2100 is not a leap year)
    QDate::isValid(1202, 6, 6);   // true (even though 1202 is pre-Gregorian)

See Also:
isNull, setDate

longDayName

public static java.lang.String longDayName(int weekday)

Returns the long name of the weekday using the following convention:

The day names will be localized according to the system's locale settings.

See Also:
toString, shortDayName, shortMonthName, longMonthName

longMonthName

public static java.lang.String longMonthName(int month)

Returns the long name of the month using the following convention:

The month names will be localized according to the system's locale settings.

See Also:
toString, shortMonthName, shortDayName, longDayName

shortDayName

public static java.lang.String shortDayName(int weekday)

Returns the name of the weekday using the following convention:

The day names will be localized according to the system's locale settings.

See Also:
toString, shortMonthName, longMonthName, longDayName

shortMonthName

public static java.lang.String shortMonthName(int month)

Returns the name of the month using the following convention:

The month names will be localized according to the system's locale settings.

See Also:
toString, longMonthName, shortDayName, longDayName

fromNativePointer

public static QDate fromNativePointer(QNativePointer nativePointer)
This function returns the QDate instance pointed to by nativePointer

Parameters:
nativePointer - the QNativePointer of which object should be returned.

nativePointerArray

public static QNativePointer nativePointerArray(QDate[] array)
This function returns a QNativePointer that is pointing to the specified QDate array.

Parameters:
array - the array that the returned pointer will point to.
Returns:
a QNativePointer that is pointing to the specified array.

equals

public boolean equals(java.lang.Object other)

Overrides:
equals in class java.lang.Object

compareTo

public int compareTo(java.lang.Object other)

Specified by:
compareTo in interface java.lang.Comparable

weekNumber

public final int weekNumber()
Returns the week number (1 to 53).

Returns null if the date is invalid.

In accordance with ISO 8601, weeks start on Qt.DayOfWeek.Monday and the first Qt.DayOfWeek.Thursday of a year is always in week 1 of that year. Most years have 52 weeks, but some have 53.

Copyright (c) 1989 The Regents of the University of California. All rights reserved.

Redistribution and use in source and binary forms are permitted provided that the above copyright notice and this paragraph are duplicated in all such forms and that any documentation, advertising materials, and other materials related to such distribution and use acknowledge that the software was developed by the University of California, Berkeley. The name of the University may not be used to endorse or promote products derived from this software without specific prior written permission. THIS SOFTWARE IS PROVIDED "AS IS" AND WITHOUT ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, WITHOUT LIMITATION, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE.


yearOfWeekNumber

public final int yearOfWeekNumber()
This function returns the year number of the QDate's current week.


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