CopperSpice API  1.7.2
QTime Class Reference

Provides clock time functions. More...

Public Methods

constexpr QTime ()
 
 QTime (int h, int m, int s=0, int ms=0)
 
QTime addMSecs (int ms) const
 
QTime addSecs (int secs) const
 
int elapsed () const
 
int hour () const
 
constexpr bool isNull () const
 
bool isValid () const
 
int minute () const
 
int msec () const
 
int msecsSinceStartOfDay () const
 
int msecsTo (const QTime &value) const
 
bool operator!= (const QTime &value) const
 
bool operator< (const QTime &value) const
 
bool operator<= (const QTime &value) const
 
bool operator== (const QTime &value) const
 
bool operator> (const QTime &value) const
 
bool operator>= (const QTime &value) const
 
int restart ()
 
int second () const
 
int secsTo (const QTime &value) const
 
bool setHMS (int h, int m, int s, int ms=0)
 
void start ()
 
QString toString (const QString &format) const
 
QString toString (Qt::DateFormat format=Qt::TextDate) const
 

Static Public Methods

static QTime currentTime ()
 
static QTime fromMSecsSinceStartOfDay (int msecs)
 
static QTime fromString (const QString &str, const QString &format)
 
static QTime fromString (const QString &str, Qt::DateFormat format=Qt::TextDate)
 
static bool isValid (int h, int m, int s, int ms=0)
 

Friends

QDataStreamoperator<< (QDataStream &, const QTime &)
 
QDataStreamoperator>> (QDataStream &, QTime &)
 
class QDateTime
 

Detailed Description

The QTime class provides clock time functions. A QTime object contains a clock time, i.e. the number of hours, minutes, seconds, and milliseconds since midnight. It can read the current time from the system clock and measure a span of elapsed time. It provides functions for comparing times and for manipulating a time by adding a number of milliseconds.

QTime uses the 24-hour clock format and has no concept of AM/PM. Unlike QDateTime, QTime knows nothing about time zones or daylight savings time (DST).

A QTime object is typically created either by giving the number of hours, minutes, seconds, and milliseconds explicitly, or by using the static function currentTime(), which creates a QTime object that contains the system's local time. Note that the accuracy depends on the accuracy of the underlying operating system; not all systems provide 1-millisecond accuracy.

The hour(), minute(), second(), and msec() functions provide access to the number of hours, minutes, seconds, and milliseconds of the time. The same information is provided in textual format by the toString() function.

QTime provides a full set of operators to compare two QTime objects. One time is considered smaller than another if it is earlier than the other.

The time a given number of seconds or milliseconds later than a given time can be found using the addSecs() or addMSecs() functions. Correspondingly, the number of seconds or milliseconds between two times can be found using secsTo() or msecsTo().

QTime can be used to measure a span of elapsed time using the start(), restart(), and elapsed() functions.

See also
QDate, QDateTime

Constructor & Destructor Documentation

constexpr QTime::QTime ( )
inlineconstexpr

Constructs a null QTime.

The isNull() method will return true, isValid() will return false, and the time will be set to midnight which is QTime(0, 0, 0, 0).

See also
isNull(), isValid()
QTime::QTime ( int  h,
int  m,
int  s = 0,
int  ms = 0 
)

Constructs a time with hour h, minute m, seconds s and milliseconds ms. The value for h must be in the range 0 to 23, m and s must be in the range 0 to 59, and ms must be in the range 0 to 999.

See also
isValid()

Method Documentation

QTime QTime::addMSecs ( int  ms) const
nodiscard

Returns a QTime containing the time plus ms milliseconds. If ms is negative the result is the QTime value minus the given ms value. The time will wrap if it crosses midnight.

See also
addSecs(), msecsTo(), QDateTime::addMSecs()
QTime QTime::addSecs ( int  secs) const
nodiscard

Returns a QTime containing the time plus secs seconds. If ms is negative the result is the QTime value minus the given s value. The time will wrap if it crosses midnight.

QTime n(14, 0, 0); // n == 14:00:00
t = n.addSecs(70); // t == 14:01:10
t = n.addSecs(-70); // t == 13:58:50
t = n.addSecs(10 * 60 * 60 + 5); // t == 00:00:05
t = n.addSecs(-15 * 60 * 60); // t == 23:00:00
See also
addMSecs(), secsTo(), QDateTime::addSecs()
QTime QTime::currentTime ( )
static

Returns the current time as reported by the system clock.

Note that the accuracy depends on the accuracy of the underlying operating system; not all systems provide 1-millisecond accuracy.

int QTime::elapsed ( ) const

Returns the number of milliseconds that have elapsed since the last time start() or restart() was called.

Note that the counter wraps to zero 24 hours after the last call to start() or restart.

Note that the accuracy depends on the accuracy of the underlying operating system; not all systems provide 1-millisecond accuracy.

Warning
If the system's clock setting has been changed since the last time start() or restart() was called, the result is undefined. This can happen when daylight savings time is turned on or off.
See also
start(), restart()
QTime QTime::fromMSecsSinceStartOfDay ( int  msecs)
inlinestatic

Returns a new QTime instance with the time set to the number of msecs since the start of the day, i.e. since 00:00:00.

If msecs falls outside the valid range an invalid QTime will be returned.

See also
msecsSinceStartOfDay()
QTime QTime::fromString ( const QString str,
const QString format 
)
static

Returns the QTime represented by the str, using the format given, or an invalid time if the string can not be parsed.

These expressions may be used for the format parameter.

Expression Output
hthe hour without a leading zero (0 to 23 or 1 to 12 if AM/PM display)
hhthe hour with a leading zero (00 to 23 or 01 to 12 if AM/PM display)
mthe minute without a leading zero (0 to 59)
mmthe minute with a leading zero (00 to 59)
sthe second without a leading zero (0 to 59)
ssthe second with a leading zero (00 to 59)
zthe milliseconds without leading zeroes (0 to 999)
zzzthe milliseconds with leading zeroes (000 to 999)
APinterpret as an AM/PM time. AP must be either "AM" or "PM".
apInterpret as an AM/PM time. ap must be either "am" or "pm".

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 not be used as an expression.

QTime time = QTime::fromString("1mm12car00", "m'mm'hcarss"); // time is 12:01.00

If the format is not satisfied an invalid QTime is returned. Expressions that do not expect leading zeroes to be given (h, m, s and z) are greedy. This means that they will use two digits even if this puts them outside the range of accepted values and leaves too few digits for other sections. For example, the following string could have meant 00:07:10, but the m will grab two digits, resulting in an invalid time.

QTime time = QTime::fromString("00:710", "hh:ms"); // invalid

Any field that is not represented in the format will be set to zero. For example:

QTime time = QTime::fromString("1.30", "m.s");
// time is 00:01:30.000

QDateTime::toString() QTime::toString()

See also
QDateTime::fromString(), QDate::fromString(), QDate::toString()
QTime QTime::fromString ( const QString str,
Qt::DateFormat  format = Qt::TextDate 
)
static

Returns the time represented in the str as a QTime using the format given, or an invalid time if this is not possible.

Note that fromString() uses a "C" locale encoded string to convert milliseconds to a float value. If the default locale is not "C", this may result in two conversion attempts (if the conversion fails for the default locale). This should be considered an implementation detail.

int QTime::hour ( ) const

Returns the hour part (0 to 23) of the time.

See also
minute(), second(), msec()
constexpr bool QTime::isNull ( ) const
inlineconstexpr

Returns true if the time is null (i.e., the QTime object was constructed using the default constructor), otherwise returns false. A null time is also an invalid time.

See also
isValid()
bool QTime::isValid ( ) const

Returns true if the time is valid, otherwise returns false. For example, the time 23:30:55.746 is valid, but 24:12:30 is invalid.

See also
isNull()
bool QTime::isValid ( int  h,
int  m,
int  s,
int  ms = 0 
)
static

Returns true if the specified time is valid, otherwise returns false.

The time is valid if h is in the range 0 to 23, m and s are in the range 0 to 59, and ms is in the range 0 to 999.

QTime::isValid(21, 10, 30); // returns true
QTime::isValid(22, 5, 62); // returns false
int QTime::minute ( ) const

Returns the minute part (0 to 59) of the time.

See also
hour(), second(), msec()
int QTime::msec ( ) const

Returns the millisecond part (0 to 999) of the time.

See also
hour(), minute(), second()
int QTime::msecsSinceStartOfDay ( ) const
inline

Returns the number of msecs since the start of the day which is 00:00:00.

See also
fromMSecsSinceStartOfDay()
int QTime::msecsTo ( const QTime &  value) const

Returns the number of milliseconds from this time to value. If value is earlier than this time, the number of milliseconds returned is negative.

Because QTime measures time within a day and there are 86400 seconds in a day, the result is always between -86400000 and 86400000 ms.

See also
secsTo(), addMSecs(), QDateTime::msecsTo()
bool QTime::operator!= ( const QTime &  value) const
inline

Returns true if this time is different from value, otherwise returns false.

bool QTime::operator< ( const QTime &  value) const
inline

Returns true if this time is earlier than value, otherwise returns false.

bool QTime::operator<= ( const QTime &  value) const
inline

Returns true if this time is earlier than or equal to value, otherwise returns false.

bool QTime::operator== ( const QTime &  value) const
inline

Returns true if this time is equal to value, otherwise returns false.

bool QTime::operator> ( const QTime &  value) const
inline

Returns true if this time is later than value, otherwise returns false.

bool QTime::operator>= ( const QTime &  value) const
inline

Returns true if this time is later than or equal to value, otherwise returns false.

int QTime::restart ( )

Sets this time to the current time and returns the number of milliseconds that have elapsed since the last time start() or restart() was called.

This method is useful repeated measurements. Call start() to start the first measurement, and then restart() for each later measurement.

Warning
If the system clock setting has been changed since the last time start() or restart() was called, the result is undefined. This can happen when daylight savings time is turned on or off.
See also
start(), elapsed(), currentTime()
int QTime::second ( ) const

Returns the second part (0 to 59) of the time.

See also
hour(), minute(), msec()
int QTime::secsTo ( const QTime &  value) const

Returns the number of seconds from this time to value. If value is earlier than this time the number of seconds returned is negative.

Because QTime measures time within a day and there are 86400 seconds in a day the result is always between -86400 and 86400.

This method does not take into account any milliseconds.

See also
addSecs(), QDateTime::secsTo()
bool QTime::setHMS ( int  h,
int  m,
int  s,
int  ms = 0 
)

Sets the time to hour h, minute m, seconds s and milliseconds ms. Returns true if the set time is valid, otherwise returns false.

The value for h must be in the range 0 to 23, m and s must be in the range 0 to 59, and ms must be in the range 0 to 999.

See also
isValid()
void QTime::start ( )

Sets this time to the current time. This is practical for timing:

t.start();
some_lengthy_task();
qDebug("Time elapsed: %d ms", t.elapsed());
See also
restart(), elapsed(), currentTime()
QString QTime::toString ( const QString format) const

Returns the time as a string. The format parameter determines the format of the result string. If the time is invalid an empty string will be returned. If format is empty the default format "hh:mm:ss" is used.

The following expressions may be used.

Expression Output
hthe hour without a leading zero (0 to 23 or 1 to 12 if AM/PM display)
hhthe hour with a leading zero (00 to 23 or 01 to 12 if AM/PM display)
Hthe hour without a leading zero (0 to 23, even with AM/PM display)
HHthe hour with a leading zero (00 to 23, even with AM/PM display)
mthe minute without a leading zero (0 to 59)
mmthe minute with a leading zero (00 to 59)
sthe second without a leading zero (0 to 59)
ssthe second with a leading zero (00 to 59)
zthe milliseconds without leading zeroes (0 to 999)
zzzthe milliseconds with leading zeroes (000 to 999)
AP or Ause AM/PM display. AP will be replaced by either "AM" or "PM".
ap or ause am/pm display. ap will be replaced by either "am" or "pm".
tthe timezone (for example "CEST")

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.

These are example format strings (assuming that the QTime is 14:13:09.042)

Format Result
hh:mm:ss.zzz14:13:09.042
h:m:s ap2:13:9 pm
H:m:s a14:13:9 pm
See also
QDate::toString(), QDateTime::toString()
QString QTime::toString ( Qt::DateFormat  format = Qt::TextDate) const

Returns the time as a string. If the time is invalid an empty string will be returned. Milliseconds are not included. The format parameter determines the format of the string.

If the format is Qt::TextDate the string format is HH:MM:SS. For example, 1 second before midnight would be "23:59:59".

If format is Qt::ISODate the string format corresponds to the ISO 8601 extended specification for representations of dates, which is also HH:mm:ss. Contrary to ISO 8601 dates before 15 October 1582 are handled as Julian dates, not Gregorian dates.

If the format is Qt::SystemLocaleShortDate or Qt::SystemLocaleLongDate, the string format depends on the locale settings of the system. Identical to calling QLocale::system().toString(time, QLocale::ShortFormat) or QLocale::system().toString(time, QLocale::LongFormat).

If the format is Qt::DefaultLocaleShortDate or Qt::DefaultLocaleLongDate, 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(time, QLocale::ShortFormat) or QLocale().toString(time, QLocale::LongFormat).

Friends And Related Function Documentation

QDataStream & operator<< ( QDataStream out,
const QTime &  value 
)
friend

Writes value to stream out. Refer to Serializing Data Types for additional information.

QDataStream & operator>> ( QDataStream in,
QTime &  value 
)
friend

Reads a time from stream in into the given value. Refer to Serializing Data Types for additional information.