Qt
Internal/Contributor docs for the Qt SDK. <b>Note:</b> These are NOT official API docs; those are found <a href='https://doc.qt.io/'>here</a>.
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\inmodule QtCore More...
#include <qchronotimer.h>
Public Slots | |
void | start () |
void | stop () |
Stops the timer. | |
Public Slots inherited from QObject | |
void | deleteLater () |
\threadsafe | |
Signals | |
void | timeout (QPrivateSignal) |
This signal is emitted when the timer times out. | |
Signals inherited from QObject | |
void | destroyed (QObject *=nullptr) |
This signal is emitted immediately before the object obj is destroyed, after any instances of QPointer have been notified, and cannot be blocked. | |
void | objectNameChanged (const QString &objectName, QPrivateSignal) |
This signal is emitted after the object's name has been changed. | |
Public Member Functions | |
QChronoTimer (std::chrono::nanoseconds nsec, QObject *parent=nullptr) | |
Constructs a timer with the given parent, using an interval of nsec. | |
QChronoTimer (QObject *parent=nullptr) | |
Constructs a timer with the given parent, using the default interval, 0ns . | |
~QChronoTimer () override | |
Destroys the timer. | |
bool | isActive () const |
Returns true if the timer is running (pending); otherwise returns false. | |
QBindable< bool > | bindableActive () |
Qt::TimerId | id () const |
Returns a Qt::TimerId representing the timer ID if the timer is running; otherwise returns Qt::TimerId::Invalid . | |
void | setInterval (std::chrono::nanoseconds nsec) |
std::chrono::nanoseconds | interval () const |
QBindable< std::chrono::nanoseconds > | bindableInterval () |
std::chrono::nanoseconds | remainingTime () const |
void | setTimerType (Qt::TimerType atype) |
Qt::TimerType | timerType () const |
QBindable< Qt::TimerType > | bindableTimerType () |
void | setSingleShot (bool singleShot) |
bool | isSingleShot () const |
QBindable< bool > | bindableSingleShot () |
template<typename ... Args> | |
QMetaObject::Connection | callOnTimeout (Args &&...args) |
Public Member Functions inherited from QObject | |
Q_INVOKABLE | QObject (QObject *parent=nullptr) |
Constructs an object with parent object parent. | |
virtual | ~QObject () |
Destroys the object, deleting all its child objects. | |
virtual bool | event (QEvent *event) |
This virtual function receives events to an object and should return true if the event e was recognized and processed. | |
virtual bool | eventFilter (QObject *watched, QEvent *event) |
Filters events if this object has been installed as an event filter for the watched object. | |
QString | objectName () const |
Q_WEAK_OVERLOAD void | setObjectName (const QString &name) |
Sets the object's name to name. | |
void | setObjectName (QAnyStringView name) |
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. | |
QBindable< QString > | bindableObjectName () |
bool | isWidgetType () const |
Returns true if the object is a widget; otherwise returns false . | |
bool | isWindowType () const |
Returns true if the object is a window; otherwise returns false . | |
bool | isQuickItemType () const |
Returns true if the object is a QQuickItem; otherwise returns false . | |
bool | signalsBlocked () const noexcept |
Returns true if signals are blocked; otherwise returns false . | |
bool | blockSignals (bool b) noexcept |
If block is true, signals emitted by this object are blocked (i.e., emitting a signal will not invoke anything connected to it). | |
QThread * | thread () const |
Returns the thread in which the object lives. | |
bool | moveToThread (QThread *thread QT6_DECL_NEW_OVERLOAD_TAIL) |
Changes the thread affinity for this object and its children and returns true on success. | |
int | startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer) |
This is an overloaded function that will start a timer of type timerType and a timeout of interval milliseconds. | |
int | startTimer (std::chrono::nanoseconds time, Qt::TimerType timerType=Qt::CoarseTimer) |
void | killTimer (int id) |
Kills the timer with timer identifier, id. | |
void | killTimer (Qt::TimerId id) |
template<typename T > | |
T | findChild (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const |
Returns the child of this object that can be cast into type T and that is called name, or \nullptr if there is no such object. | |
template<typename T > | |
QList< T > | findChildren (QAnyStringView aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const |
Returns all children of this object with the given name that can be cast to type T, or an empty list if there are no such objects. | |
template<typename T > | |
T | findChild (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const |
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. | |
template<typename T > | |
QList< T > | findChildren (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const |
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. | |
const QObjectList & | children () const |
Returns a list of child objects. | |
void | setParent (QObject *parent) |
Makes the object a child of parent. | |
void | installEventFilter (QObject *filterObj) |
Installs an event filter filterObj on this object. | |
void | removeEventFilter (QObject *obj) |
Removes an event filter object obj from this object. | |
QMetaObject::Connection | connect (const QObject *sender, const char *signal, const char *member, Qt::ConnectionType type=Qt::AutoConnection) const |
bool | disconnect (const char *signal=nullptr, const QObject *receiver=nullptr, const char *member=nullptr) const |
bool | disconnect (const QObject *receiver, const char *member=nullptr) const |
void | dumpObjectTree () const |
Dumps a tree of children to the debug output. | |
void | dumpObjectInfo () const |
Dumps information about signal connections, etc. | |
bool | setProperty (const char *name, const QVariant &value) |
Sets the value of the object's name property to value. | |
bool | setProperty (const char *name, QVariant &&value) |
QVariant | property (const char *name) const |
Returns the value of the object's name property. | |
QList< QByteArray > | dynamicPropertyNames () const |
QBindingStorage * | bindingStorage () |
const QBindingStorage * | bindingStorage () const |
QObject * | parent () const |
Returns a pointer to the parent object. | |
bool | inherits (const char *classname) const |
Returns true if this object is an instance of a class that inherits className or a QObject subclass that inherits className; otherwise returns false . | |
Static Public Member Functions | |
template<typename Functor > | |
static void | singleShot (std::chrono::nanoseconds interval, const FunctorContext< Functor > *receiver, Functor &&slot) |
template<typename Functor > | |
static void | singleShot (std::chrono::nanoseconds interval, Qt::TimerType timerType, const FunctorContext< Functor > *receiver, Functor &&slot) |
template<typename Functor > | |
static void | singleShot (std::chrono::nanoseconds interval, Qt::TimerType timerType, Functor &&slot) |
template<typename Functor > | |
static void | singleShot (std::chrono::nanoseconds interval, Functor &&slot) |
static void | singleShot (std::chrono::nanoseconds interval, Qt::TimerType timerType, const QObject *receiver, const char *member) |
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. \reentrant. | |
static void | singleShot (std::chrono::nanoseconds interval, const QObject *receiver, const char *member) |
Static Public Member Functions inherited from QObject | |
static QMetaObject::Connection | connect (const QObject *sender, const char *signal, const QObject *receiver, const char *member, Qt::ConnectionType=Qt::AutoConnection) |
\threadsafe | |
static QMetaObject::Connection | connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type=Qt::AutoConnection) |
template<typename Func1 , typename Func2 > | |
static QMetaObject::Connection | connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, const typename QtPrivate::ContextTypeForFunctor< Func2 >::ContextType *context, Func2 &&slot, Qt::ConnectionType type=Qt::AutoConnection) |
template<typename Func1 , typename Func2 > | |
static QMetaObject::Connection | connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, Func2 &&slot) |
static bool | disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *member) |
\threadsafe | |
static bool | disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &member) |
static bool | disconnect (const QMetaObject::Connection &) |
Disconnect a connection. | |
template<typename Func1 , typename Func2 > | |
static bool | disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, const typename QtPrivate::FunctionPointer< Func2 >::Object *receiver, Func2 slot) |
template<typename Func1 > | |
static bool | disconnect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, const QObject *receiver, void **zero) |
Protected Member Functions | |
void | timerEvent (QTimerEvent *) override |
\reimp | |
Protected Member Functions inherited from QObject | |
QObject * | sender () const |
Returns a pointer to the object that sent the signal, if called in a slot activated by a signal; otherwise it returns \nullptr. | |
int | senderSignalIndex () const |
int | receivers (const char *signal) const |
Returns the number of receivers connected to the signal. | |
bool | isSignalConnected (const QMetaMethod &signal) const |
virtual void | childEvent (QChildEvent *event) |
This event handler can be reimplemented in a subclass to receive child events. | |
virtual void | customEvent (QEvent *event) |
This event handler can be reimplemented in a subclass to receive custom events. | |
virtual void | connectNotify (const QMetaMethod &signal) |
virtual void | disconnectNotify (const QMetaMethod &signal) |
QObject (QObjectPrivate &dd, QObject *parent=nullptr) | |
Properties | |
bool | singleShot |
Whether the timer is a single-shot timer. | |
std::chrono::nanoseconds | interval |
The timeout interval. | |
std::chrono::nanoseconds | remainingTime |
The remaining time. | |
Qt::TimerType | timerType |
Controls the accuracy of the timer. | |
bool | active |
This boolean property is true if the timer is running; otherwise false . | |
Properties inherited from QObject | |
QString | objectName |
the name of this object | |
Additional Inherited Members | |
Protected Attributes inherited from QObject | |
QScopedPointer< QObjectData > | d_ptr |
Related Symbols inherited from QObject | |
template< class T > T | qobject_cast (const QObject *object) |
Returns the given object cast to type T if the object is of type T (or of a subclass); otherwise returns \nullptr. | |
template< typename T > T | qFindChildqFindChildren (const QObject *obj, const QString &name)() |
template< typename T > QList< T > | qFindChildrenqFindChildren (const QObject *obj, const QString &name)() |
QObjectList | |
\macro Q_CLASSINFO(Name, Value) | |
\inmodule QtCore
The QChronoTimer class provides repetitive and single-shot timers.
The QChronoTimer class provides a high-level programming interface for timers. To use it, create a QChronoTimer, either passing the interval to the constructor, or setting it after construction using setInterval(), connect its timeout() signal to the appropriate slots, and call start(). From then on, it will emit the timeout() signal at constant intervals. For example:
You can set a timer to time out only once by calling setSingleShot(true).
QChronoTimer also has singleShot() static methods:
In multithreaded applications, you can use QChronoTimer in any thread that has an event loop. To start an event loop from a non-GUI thread, use QThread::exec(). Qt uses the timer's \l{QObject::thread()}{thread affinity} to determine which thread will emit the \l{QChronoTimer::}{timeout()} signal. Because of this, you must start and stop the timer in its thread; it is not possible to start a timer from another thread.
As a special case, a QChronoTimer with a timeout of 0ns
will time out as soon as possible, though the ordering between zero timers and other sources of events is unspecified. Zero timers can be used to do some work while still providing a responsive user interface:
From then on, processOneThing()
will be called repeatedly. It should be written in such a way that it always returns quickly (for example, after processing one data item) so that Qt can deliver events to the user interface and stop the timer as soon as it has done all its work. This is the traditional way of implementing heavy work in GUI applications, but as multithreading is becoming available on more platforms, a modern alternative is doing the heavy work in a thread other than the GUI (main) thread. Qt has the QThread class, which can be used to achieve that.
Definition at line 19 of file qchronotimer.h.
Constructs a timer with the given parent, using an interval of nsec.
Definition at line 125 of file qchronotimer.cpp.
References Q_ASSERT.
Constructs a timer with the given parent, using the default interval, 0ns
.
Definition at line 117 of file qchronotimer.cpp.
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override |
Destroys the timer.
Definition at line 134 of file qchronotimer.cpp.
References isActive(), and stop().
QBindable< bool > QChronoTimer::bindableActive | ( | ) |
Definition at line 164 of file qchronotimer.cpp.
QBindable< std::chrono::nanoseconds > QChronoTimer::bindableInterval | ( | ) |
Definition at line 313 of file qchronotimer.cpp.
QBindable< bool > QChronoTimer::bindableSingleShot | ( | ) |
Definition at line 266 of file qchronotimer.cpp.
QBindable< Qt::TimerType > QChronoTimer::bindableTimerType | ( | ) |
Definition at line 355 of file qchronotimer.cpp.
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inline |
Definition at line 106 of file qchronotimer.h.
References args, QObject::connect(), and timeout().
Qt::TimerId QChronoTimer::id | ( | ) | const |
Returns a Qt::TimerId representing the timer ID if the timer is running; otherwise returns Qt::TimerId::Invalid
.
Definition at line 175 of file qchronotimer.cpp.
References QTimerPrivate::id.
Referenced by start().
std::chrono::nanoseconds QChronoTimer::interval | ( | ) | const |
Definition at line 308 of file qchronotimer.cpp.
bool QChronoTimer::isActive | ( | ) | const |
Returns true
if the timer is running (pending); otherwise returns false.
Definition at line 159 of file qchronotimer.cpp.
Referenced by ~QChronoTimer(), and remainingTime().
bool QChronoTimer::isSingleShot | ( | ) | const |
Definition at line 261 of file qchronotimer.cpp.
std::chrono::nanoseconds QChronoTimer::remainingTime | ( | ) | const |
Definition at line 330 of file qchronotimer.cpp.
References QAbstractEventDispatcher::instance(), and isActive().
void QChronoTimer::setInterval | ( | std::chrono::nanoseconds | nsec | ) |
Definition at line 285 of file qchronotimer.cpp.
References d, Qt::Invalid, QObject::killTimer(), and QObject::startTimer().
void QChronoTimer::setSingleShot | ( | bool | singleShot | ) |
Definition at line 256 of file qchronotimer.cpp.
References singleShot.
void QChronoTimer::setTimerType | ( | Qt::TimerType | atype | ) |
Definition at line 345 of file qchronotimer.cpp.
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inlinestatic |
Definition at line 68 of file qchronotimer.h.
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inlinestatic |
Definition at line 96 of file qchronotimer.h.
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inlinestatic |
Definition at line 89 of file qchronotimer.h.
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inlinestatic |
Definition at line 74 of file qchronotimer.h.
References void.
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static |
This is an overloaded member function, provided for convenience. It differs from the above function only in what argument(s) it accepts. \reentrant.
This static function calls the slot member, on object receiver, after time interval interval. timerType affects the precision of the timer
member has to be a member function of receiver; you need to use the SLOT()
macro to get this parameter.
This function is provided as a convenience to save the need to use a \l{QObject::timerEvent()}{timerEvent} or create a local QChronoTimer object.
Definition at line 376 of file qchronotimer.cpp.
References interval, QMetaObject::invokeMethod(), methodName(), Q_UNLIKELY, Qt::QueuedConnection, qWarning, timerType, QByteArrayView::trimmed(), and void.
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inlinestatic |
Definition at line 84 of file qchronotimer.h.
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slot |
Definition at line 189 of file qchronotimer.cpp.
References d, id(), Qt::Invalid, QObject::startTimer(), and stop().
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slot |
Stops the timer.
Definition at line 206 of file qchronotimer.cpp.
References d, Qt::Invalid, and QObject::killTimer().
Referenced by ~QChronoTimer(), start(), and timerEvent().
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signal |
This signal is emitted when the timer times out.
Referenced by callOnTimeout().
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overrideprotectedvirtual |
\reimp
Reimplemented from QObject.
Definition at line 219 of file qchronotimer.cpp.
References d, Q_EMIT, stop(), and QTimerEvent::timerId().
Qt::TimerType QChronoTimer::timerType | ( | ) | const |
Definition at line 350 of file qchronotimer.cpp.
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read |
This boolean property is true
if the timer is running; otherwise false
.
Definition at line 29 of file qchronotimer.h.
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readwrite |
The timeout interval.
The default value for this property is 0ns
.
A QChronoTimer with a timeout of 0ns
will time out as soon as all the events in the window system's event queue have been processed.
Setting the interval of an active timer changes the interval and acquires a new id(). If the timer is not active, only the interval is changed.
Definition at line 24 of file qchronotimer.h.
Referenced by singleShot().
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read |
The remaining time.
Returns the remaining duration until the timeout.
If the timer is inactive, the returned duration will be negative.
If the timer is overdue, the returned duration will be 0ns
.
Definition at line 26 of file qchronotimer.h.
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readwrite |
Whether the timer is a single-shot timer.
A single-shot timer fires only once, non-single-shot timers fire every \l interval.
The default value for this property is false
.
Definition at line 22 of file qchronotimer.h.
Referenced by setSingleShot().
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readwrite |
Controls the accuracy of the timer.
The default value for this property is Qt::CoarseTimer
.
Definition at line 27 of file qchronotimer.h.
Referenced by singleShot().