The QTimeLine class provides a timeline for controlling animations. More...

#include <qtimeline.h>

Inheritance diagram for QTimeLine:

Collaboration diagram for QTimeLine:

Public Types
enum	State { NotRunning , Paused , Running }

enum	Direction { Forward , Backward }

Public Slots
void	start ()

void	resume ()

void	stop ()

void	setPaused (bool paused)

void	setCurrentTime (int msec)

void	toggleDirection ()

Public Slots inherited from QObject
void	deleteLater ()

Signals
void	valueChanged (qreal x, QPrivateSignal)

void	frameChanged (int, QPrivateSignal)

void	stateChanged (QTimeLine::State newState, QPrivateSignal)

void	finished (QPrivateSignal)

Signals inherited from QObject
void	destroyed (QObject *=nullptr)

void	objectNameChanged (const QString &objectName, QPrivateSignal)

Public Member Functions
	QTimeLine (int duration=1000, QObject *parent=nullptr)

virtual	~QTimeLine ()

State	state () const

int	loopCount () const

void	setLoopCount (int count)

QBindable< int >	bindableLoopCount ()

Direction	direction () const

void	setDirection (Direction direction)

QBindable< Direction >	bindableDirection ()

int	duration () const

void	setDuration (int duration)

QBindable< int >	bindableDuration ()

int	startFrame () const

void	setStartFrame (int frame)

int	endFrame () const

void	setEndFrame (int frame)

void	setFrameRange (int startFrame, int endFrame)

int	updateInterval () const

void	setUpdateInterval (int interval)

QBindable< int >	bindableUpdateInterval ()

QEasingCurve	easingCurve () const

void	setEasingCurve (const QEasingCurve &curve)

QBindable< QEasingCurve >	bindableEasingCurve ()

int	currentTime () const

QBindable< int >	bindableCurrentTime ()

int	currentFrame () const

qreal	currentValue () const

int	frameForTime (int msec) const

virtual qreal	valueForTime (int msec) const

Public Member Functions inherited from QObject
Q_INVOKABLE	QObject (QObject *parent=nullptr)

virtual	~QObject ()

virtual bool	event (QEvent *event)

virtual bool	eventFilter (QObject watched, QEvent event)

QString	objectName () const

void	setObjectName (const QString &name)

QBindable< QString >	bindableObjectName ()

bool	isWidgetType () const

bool	isWindowType () const

bool	signalsBlocked () const noexcept

bool	blockSignals (bool b) noexcept

QThread *	thread () const

void	moveToThread (QThread *thread)

int	startTimer (int interval, Qt::TimerType timerType=Qt::CoarseTimer)

void	killTimer (int id)

template<typename T >
T	findChild (const QString &aName=QString(), Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

template<typename T >
QList< T >	findChildren (const QString &aName, Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

template<typename T >
QList< T >	findChildren (Qt::FindChildOptions options=Qt::FindChildrenRecursively) const

const QObjectList &	children () const

void	setParent (QObject *parent)

void	installEventFilter (QObject *filterObj)

void	removeEventFilter (QObject *obj)

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

void	dumpObjectInfo () const

bool	setProperty (const char *name, const QVariant &value)

QVariant	property (const char *name) const

QList< QByteArray >	dynamicPropertyNames () const

QBindingStorage *	bindingStorage ()

const QBindingStorage *	bindingStorage () const

QObject *	parent () const

bool	inherits (const char *classname) const

Protected Member Functions
void	timerEvent (QTimerEvent *event) override

Protected Member Functions inherited from QObject
QObject *	sender () const

int	senderSignalIndex () const

int	receivers (const char *signal) const

bool	isSignalConnected (const QMetaMethod &signal) const

virtual void	childEvent (QChildEvent *event)

virtual void	customEvent (QEvent *event)

virtual void	connectNotify (const QMetaMethod &signal)

virtual void	disconnectNotify (const QMetaMethod &signal)

	QObject (QObjectPrivate &dd, QObject *parent=nullptr)

Properties
int	duration
	the total duration of the timeline in milliseconds. More...

int	updateInterval
	the time in milliseconds between each time QTimeLine updates its current time. More...

int	currentTime
	the current time of the time line. More...

Direction	direction
	the direction of the timeline when QTimeLine is in \l Running state. More...

int	loopCount
	the number of times the timeline should loop before it's finished. More...

QEasingCurve	easingCurve

Properties inherited from QObject
QString	objectName
	the name of this object More...

Additional Inherited Members
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)

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::FunctionPointer< Func2 >::Object receiver, Func2 slot, Qt::ConnectionType type=Qt::AutoConnection)

static QMetaObject::Connection ::type	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, Func2 slot)

static QMetaObject::Connection ::type	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const QObject context, Func2 slot, Qt::ConnectionType type=Qt::AutoConnection)

template<typename Func1 , typename Func2 >
static std::enable_if< QtPrivate::FunctionPointer< Func2 >::ArgumentCount==-1 &&!std::is_convertible_v< Func2, const char * >, QMetaObject::Connection >::type	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object *sender, Func1 signal, Func2 slot)

template<typename Func1 , typename Func2 >
static std::enable_if< QtPrivate::FunctionPointer< Func2 >::ArgumentCount==-1 &&!std::is_convertible_v< Func2, const char * >, QMetaObject::Connection >::type	connect (const typename QtPrivate::FunctionPointer< Func1 >::Object sender, Func1 signal, const QObject context, Func2 slot, Qt::ConnectionType type=Qt::AutoConnection)

static bool	disconnect (const QObject sender, const char signal, const QObject receiver, const char member)

static bool	disconnect (const QObject sender, const QMetaMethod &signal, const QObject receiver, const QMetaMethod &member)

static bool	disconnect (const QMetaObject::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 Attributes inherited from QObject
QScopedPointer< QObjectData >	d_ptr

Related Functions inherited from QObject
template< class T > T	qobject_cast (const QObject *object)

template< typename T > T	qFindChildqFindChildren (const QObject *obj, const QString &name)()

template< typename T > QList< T >	qFindChildrenqFindChildren (const QObject *obj, const QString &name)()

	QObjectList

Detailed Description

The QTimeLine class provides a timeline for controlling animations.

\inmodule QtCore

Since: 4.2

It's most commonly used to animate a GUI control by calling a slot periodically. You can construct a timeline by passing its duration in milliseconds to QTimeLine's constructor. The timeline's duration describes for how long the animation will run. Then you set a suitable frame range by calling setFrameRange(). Finally connect the frameChanged() signal to a suitable slot in the widget you wish to animate (for example, \l {QProgressBar::}{setValue()} in QProgressBar). When you proceed to calling start(), QTimeLine will enter Running state, and start emitting frameChanged() at regular intervals, causing your widget's connected property's value to grow from the lower end to the upper and of your frame range, at a steady rate. You can specify the update interval by calling setUpdateInterval(). When done, QTimeLine enters NotRunning state, and emits finished().

Example:

By default the timeline runs once, from its beginning to its end, upon which you must call start() again to restart from the beginning. To make the timeline loop, you can call setLoopCount(), passing the number of times the timeline should run before finishing. The direction can also be changed, causing the timeline to run backward, by calling setDirection(). You can also pause and unpause the timeline while it's running by calling setPaused(). For interactive control, the setCurrentTime() function is provided, which sets the time position of the time line directly. Although most useful in NotRunning state (e.g., connected to a valueChanged() signal in a QSlider), this function can be called at any time.

The frame interface is useful for standard widgets, but QTimeLine can be used to control any type of animation. The heart of QTimeLine lies in the valueForTime() function, which generates a value between 0 and 1 for a given time. This value is typically used to describe the steps of an animation, where 0 is the first step of an animation, and 1 is the last step. When running, QTimeLine generates values between 0 and 1 by calling valueForTime() and emitting valueChanged(). By default, valueForTime() applies an interpolation algorithm to generate these value. You can choose from a set of predefined timeline algorithms by calling setEasingCurve().

Note that, by default, QTimeLine uses QEasingCurve::InOutSine, which provides a value that grows slowly, then grows steadily, and finally grows slowly. For a custom timeline, you can reimplement valueForTime(), in which case QTimeLine's easingCurve property is ignored.

See also: QProgressBar, QProgressDialog

Definition at line 54 of file qtimeline.h.

Member Enumeration Documentation

◆ Direction

enum QTimeLine::Direction

This enum describes the direction of the timeline when in \l Running state.

\value Forward The current time of the timeline increases with time (i.e., moves from 0 and towards the end / duration).

\value Backward The current time of the timeline decreases with time (i.e., moves from the end / duration and towards 0).

See also: setDirection()

Enumerator
Forward
Backward

Definition at line 71 of file qtimeline.h.

◆ State

enum QTimeLine::State

This enum describes the state of the timeline.

\value NotRunning The timeline is not running. This is the initial state of QTimeLine, and the state QTimeLine reenters when finished. The current time, frame and value remain unchanged until either setCurrentTime() is called, or the timeline is started by calling start().

\value Paused The timeline is paused (i.e., temporarily suspended). Calling setPaused(false) will resume timeline activity.

\value Running The timeline is running. While control is in the event loop, QTimeLine will update its current time at regular intervals, emitting valueChanged() and frameChanged() when appropriate.

See also: state(), stateChanged()

Enumerator
NotRunning
Paused
Running

Definition at line 66 of file qtimeline.h.

Constructor & Destructor Documentation

◆ QTimeLine()

QTimeLine::QTimeLine	(	int	duration = `1000`,
		QObject *	parent = `nullptr`
	)

explicit

Constructs a timeline with a duration of duration milliseconds. parent is passed to QObject's constructor. The default duration is 1000 milliseconds.

Definition at line 297 of file qtimeline.cpp.

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◆ ~QTimeLine()

QTimeLine::~QTimeLine ( )

virtual

Destroys the timeline.

Definition at line 306 of file qtimeline.cpp.

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Member Function Documentation

◆ bindableCurrentTime()

QBindable< int > QTimeLine::bindableCurrentTime ( )

Definition at line 165 of file qtimeline.cpp.

◆ bindableDirection()

QBindable< QTimeLine::Direction > QTimeLine::bindableDirection ( )

Definition at line 381 of file qtimeline.cpp.

◆ bindableDuration()

QBindable< int > QTimeLine::bindableDuration ( )

Definition at line 419 of file qtimeline.cpp.

◆ bindableEasingCurve()

QBindable< QEasingCurve > QTimeLine::bindableEasingCurve ( )

Definition at line 541 of file qtimeline.cpp.

◆ bindableLoopCount()

QBindable< int > QTimeLine::bindableLoopCount ( )

Definition at line 345 of file qtimeline.cpp.

◆ bindableUpdateInterval()

QBindable< int > QTimeLine::bindableUpdateInterval ( )

Definition at line 512 of file qtimeline.cpp.

◆ currentFrame()

int QTimeLine::currentFrame ( ) const

Returns the frame corresponding to the current time.

See also: currentTime(), frameForTime(), setFrameRange()

Definition at line 581 of file qtimeline.cpp.

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◆ currentTime()

int QTimeLine::currentTime ( ) const

Definition at line 562 of file qtimeline.cpp.

◆ currentValue()

qreal QTimeLine::currentValue ( ) const

Returns the value corresponding to the current time.

See also: valueForTime(), currentFrame()

Definition at line 592 of file qtimeline.cpp.

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◆ direction()

QTimeLine::Direction QTimeLine::direction ( ) const

Definition at line 365 of file qtimeline.cpp.

◆ duration()

int QTimeLine::duration ( ) const

Definition at line 399 of file qtimeline.cpp.

◆ easingCurve()

QEasingCurve QTimeLine::easingCurve ( ) const

Definition at line 529 of file qtimeline.cpp.

◆ endFrame()

int QTimeLine::endFrame ( ) const

Returns the end frame, which is the frame corresponding to the end of the timeline (i.e., the frame for which the current value is 1).

See also: setEndFrame(), setFrameRange()

Definition at line 455 of file qtimeline.cpp.

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◆ finished

void QTimeLine::finished ( QPrivateSignal )

signal

This signal is emitted when QTimeLine finishes (i.e., reaches the end of its time line), and does not loop.

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◆ frameChanged

void QTimeLine::frameChanged	(	int	,
		QPrivateSignal
	)

signal

QTimeLine emits this signal at regular intervals when in \l Running state, but only if the current frame changes. frame is the current frame number.

See also: QTimeLine::setFrameRange(), QTimeLine::updateInterval

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◆ frameForTime()

int QTimeLine::frameForTime ( int msec ) const

Returns the frame corresponding to the time msec. This value is calculated using a linear interpolation of the start and end frame, based on the value returned by valueForTime().

See also: valueForTime(), setFrameRange()

Definition at line 605 of file qtimeline.cpp.

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◆ loopCount()

int QTimeLine::loopCount ( ) const

Definition at line 333 of file qtimeline.cpp.

◆ resume

void QTimeLine::resume ( )

slot

Resumes the timeline from the current time. QTimeLine will reenter Running state, and once it enters the event loop, it will update its current time, frame and value at regular intervals.

In contrast to start(), this function does not restart the timeline before it resumes.

See also: start(), updateInterval(), frameChanged(), valueChanged()

Definition at line 673 of file qtimeline.cpp.

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◆ setCurrentTime

void QTimeLine::setCurrentTime ( int msec )

slot

Definition at line 567 of file qtimeline.cpp.

◆ setDirection()

void QTimeLine::setDirection ( Direction direction )

Definition at line 370 of file qtimeline.cpp.

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◆ setDuration()

void QTimeLine::setDuration ( int duration )

Definition at line 404 of file qtimeline.cpp.

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◆ setEasingCurve()

void QTimeLine::setEasingCurve ( const QEasingCurve & curve )

Definition at line 535 of file qtimeline.cpp.

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◆ setEndFrame()

void QTimeLine::setEndFrame ( int frame )

Sets the end frame, which is the frame corresponding to the end of the timeline (i.e., the frame for which the current value is 1), to frame.

See also: endFrame(), startFrame(), setFrameRange()

Definition at line 467 of file qtimeline.cpp.

◆ setFrameRange()

void QTimeLine::setFrameRange	(	int	startFrame,
		int	endFrame
	)

Sets the timeline's frame counter to start at startFrame, and end and endFrame. For each time value, QTimeLine will find the corresponding frame when you call currentFrame() or frameForTime() by interpolating, using the return value of valueForTime().

When in Running state, QTimeLine also emits the frameChanged() signal when the frame changes.

See also: startFrame(), endFrame(), start(), currentFrame()

Definition at line 484 of file qtimeline.cpp.

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◆ setLoopCount()

void QTimeLine::setLoopCount ( int count )

Definition at line 339 of file qtimeline.cpp.

◆ setPaused

void QTimeLine::setPaused ( bool paused )

slot

If paused is true, the timeline is paused, causing QTimeLine to enter Paused state. No updates will be signaled until either start() or setPaused(false) is called. If paused is false, the timeline is resumed and continues where it left.

See also: state(), start()

Definition at line 708 of file qtimeline.cpp.

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◆ setStartFrame()

void QTimeLine::setStartFrame ( int frame )

Sets the start frame, which is the frame corresponding to the start of the timeline (i.e., the frame for which the current value is 0), to frame.

See also: startFrame(), endFrame(), setFrameRange()

Definition at line 443 of file qtimeline.cpp.

◆ setUpdateInterval()

void QTimeLine::setUpdateInterval ( int interval )

Definition at line 507 of file qtimeline.cpp.

◆ start

void QTimeLine::start ( )

slot

Starts the timeline. QTimeLine will enter Running state, and once it enters the event loop, it will update its current time, frame and value at regular intervals. The default interval is 40 ms (i.e., 25 times per second). You can change the update interval by calling setUpdateInterval().

The timeline will start from position 0, or the end if going backward. If you want to resume a stopped timeline without restarting, you can call resume() instead.

See also: resume(), updateInterval(), frameChanged(), valueChanged()

Definition at line 645 of file qtimeline.cpp.

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◆ startFrame()

int QTimeLine::startFrame ( ) const

Returns the start frame, which is the frame corresponding to the start of the timeline (i.e., the frame for which the current value is 0).

See also: setStartFrame(), setFrameRange()

Definition at line 431 of file qtimeline.cpp.

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◆ state()

QTimeLine::State QTimeLine::state ( ) const

Returns the state of the timeline.

See also: start(), setPaused(), stop()

Definition at line 319 of file qtimeline.cpp.

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◆ stateChanged

void QTimeLine::stateChanged	(	QTimeLine::State	newState,
		QPrivateSignal
	)

signal

This signal is emitted whenever QTimeLine's state changes. The new state is newState.

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◆ stop

void QTimeLine::stop ( )

slot

Stops the timeline, causing QTimeLine to enter NotRunning state.

See also: start()

Definition at line 691 of file qtimeline.cpp.

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◆ timerEvent()

void QTimeLine::timerEvent ( QTimerEvent * event )

overrideprotectedvirtual

\reimp

Reimplemented from QObject.

Definition at line 746 of file qtimeline.cpp.

◆ toggleDirection

void QTimeLine::toggleDirection ( )

slot

Toggles the direction of the timeline. If the direction was Forward, it becomes Backward, and vice verca.

Existing bindings of \l direction are removed.

See also: setDirection()

Definition at line 737 of file qtimeline.cpp.

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◆ updateInterval()

int QTimeLine::updateInterval ( ) const

Definition at line 502 of file qtimeline.cpp.

◆ valueChanged

void QTimeLine::valueChanged	(	qreal	x,
		QPrivateSignal
	)

signal

QTimeLine emits this signal at regular intervals when in \l Running state, but only if the current value changes. value is the current value. value is a number between 0.0 and 1.0

See also: QTimeLine::setDuration(), QTimeLine::valueForTime(), QTimeLine::updateInterval

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◆ valueForTime()

qreal QTimeLine::valueForTime ( int msec ) const

virtual

Returns the timeline value for the time msec. The returned value, which varies depending on the curve shape, is always between 0 and 1. If msec is 0, the default implementation always returns 0.

Reimplement this function to provide a custom curve shape for your timeline.

See also: easingCurve, frameForTime()

Definition at line 623 of file qtimeline.cpp.

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Property Documentation

◆ currentTime

QTimeLine::currentTime

readwrite

the current time of the time line.

When QTimeLine is in Running state, this value is updated continuously as a function of the duration and direction of the timeline. Otherwise, it is value that was current when stop() was called last, or the value set by setCurrentTime().

Note: You can bind other properties to currentTime, but it is not recommended setting bindings to it. As animation progresses, the currentTime is updated automatically, which cancels its bindings.

By default, this property contains a value of 0.

Definition at line 137 of file qtimeline.h.

◆ direction

QTimeLine::direction

readwrite

the direction of the timeline when QTimeLine is in \l Running state.

This direction indicates whether the time moves from 0 towards the timeline duration, or from the value of the duration and towards 0 after start() has been called.

Any binding of direction will be removed not only by setDirection(), but also by toggleDirection().

By default, this property is set to \l Forward.

Definition at line 137 of file qtimeline.h.

◆ duration

QTimeLine::duration

readwrite

the total duration of the timeline in milliseconds.

By default, this value is 1000 (i.e., 1 second), but you can change this by either passing a duration to QTimeLine's constructor, or by calling setDuration(). The duration must be larger than 0.

Note: Changing the duration does not cause the current time to be reset to zero or the new duration. You also need to call setCurrentTime() with the desired value.

Definition at line 137 of file qtimeline.h.

◆ easingCurve

QTimeLine::easingCurve

readwrite

Since: 4.6

Specifies the easing curve that the timeline will use. If valueForTime() is reimplemented, this value is ignored.

See also: valueForTime()

Definition at line 137 of file qtimeline.h.

◆ loopCount

QTimeLine::loopCount

readwrite

the number of times the timeline should loop before it's finished.

A loop count of of 0 means that the timeline will loop forever.

By default, this property contains a value of 1.

Definition at line 137 of file qtimeline.h.

◆ updateInterval

QTimeLine::updateInterval

readwrite

the time in milliseconds between each time QTimeLine updates its current time.

When updating the current time, QTimeLine will emit valueChanged() if the current value changed, and frameChanged() if the frame changed.

By default, the interval is 40 ms, which corresponds to a rate of 25 updates per second.

Definition at line 137 of file qtimeline.h.

The documentation for this class was generated from the following files:

src/corelib/tools/qtimeline.h
src/corelib/tools/qtimeline.cpp

Public Types

Public Slots

Signals

Public Member Functions

Protected Member Functions

Properties

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ Direction

◆ State

Constructor & Destructor Documentation

◆ QTimeLine()

◆ ~QTimeLine()

Member Function Documentation

◆ bindableCurrentTime()

◆ bindableDirection()

◆ bindableDuration()

◆ bindableEasingCurve()

◆ bindableLoopCount()

◆ bindableUpdateInterval()

◆ currentFrame()

◆ currentTime()

◆ currentValue()

◆ direction()

◆ duration()

◆ easingCurve()

◆ endFrame()

◆ finished

◆ frameChanged

◆ frameForTime()

◆ loopCount()

◆ resume

◆ setCurrentTime

◆ setDirection()

◆ setDuration()

◆ setEasingCurve()

◆ setEndFrame()

◆ setFrameRange()

◆ setLoopCount()

◆ setPaused

◆ setStartFrame()

◆ setUpdateInterval()

◆ start

◆ startFrame()

◆ state()

◆ stateChanged

◆ stop

◆ timerEvent()

◆ toggleDirection

◆ updateInterval()

◆ valueChanged

◆ valueForTime()

Property Documentation

◆ currentTime

◆ direction

◆ duration

◆ easingCurve

◆ loopCount

◆ updateInterval