Qt
Internal/Contributor docs for the Qt SDK. Note: These are NOT official API docs; those are found at https://doc.qt.io/
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\inmodule QtCore More...
#include <qtimeline.h>
Public Types | |
enum | State { NotRunning , Paused , Running } |
This enum describes the state of the timeline. More... | |
enum | Direction { Forward , Backward } |
This enum describes the direction of the timeline when in \l Running state. More... | |
Public Slots | |
void | start () |
Starts the timeline. | |
void | resume () |
Resumes the timeline from the current time. | |
void | stop () |
Stops the timeline, causing QTimeLine to enter NotRunning state. | |
void | setPaused (bool paused) |
If paused is true, the timeline is paused, causing QTimeLine to enter Paused state. | |
void | setCurrentTime (int msec) |
void | toggleDirection () |
Toggles the direction of the timeline. | |
Public Slots inherited from QObject | |
void | deleteLater () |
\threadsafe | |
Signals | |
void | valueChanged (qreal x, QPrivateSignal) |
QTimeLine emits this signal at regular intervals when in \l Running state, but only if the current value changes. | |
void | frameChanged (int, QPrivateSignal) |
QTimeLine emits this signal at regular intervals when in \l Running state, but only if the current frame changes. | |
void | stateChanged (QTimeLine::State newState, QPrivateSignal) |
This signal is emitted whenever QTimeLine's state changes. | |
void | finished (QPrivateSignal) |
This signal is emitted when QTimeLine finishes (i.e., reaches the end of its time line), and does not loop. | |
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 | |
QTimeLine (int duration=1000, QObject *parent=nullptr) | |
Constructs a timeline with a duration of duration milliseconds. | |
virtual | ~QTimeLine () |
Destroys the timeline. | |
State | state () const |
Returns the state of the timeline. | |
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 |
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). | |
void | 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. | |
int | 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). | |
void | 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. | |
void | setFrameRange (int startFrame, int endFrame) |
Sets the timeline's frame counter to start at startFrame, and end and 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 |
Returns the frame corresponding to the current time. | |
qreal | currentValue () const |
Returns the value corresponding to the current time. | |
int | frameForTime (int msec) const |
Returns the frame corresponding to the time msec. | |
virtual qreal | valueForTime (int msec) const |
Returns the timeline value for the time msec. | |
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 . | |
Protected Member Functions | |
void | timerEvent (QTimerEvent *event) 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 | |
int | duration |
the total duration of the timeline in milliseconds. | |
int | updateInterval |
the time in milliseconds between each time QTimeLine updates its current time. | |
int | currentTime |
the current time of the time line. | |
Direction | direction |
the direction of the timeline when QTimeLine is in \l Running state. | |
int | loopCount |
the number of times the timeline should loop before it's finished. | |
QEasingCurve | easingCurve |
Properties inherited from QObject | |
QString | objectName |
the name of this object | |
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) |
\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 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 QTimeLine class provides a timeline for controlling animations.
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.
Definition at line 18 of file qtimeline.h.
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).
Enumerator | |
---|---|
Forward | |
Backward |
Definition at line 35 of file qtimeline.h.
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.
Enumerator | |
---|---|
NotRunning | |
Paused | |
Running |
Definition at line 30 of file qtimeline.h.
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 266 of file qtimeline.cpp.
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virtual |
Destroys the timeline.
Definition at line 275 of file qtimeline.cpp.
QBindable< int > QTimeLine::bindableCurrentTime | ( | ) |
Definition at line 134 of file qtimeline.cpp.
QBindable< QTimeLine::Direction > QTimeLine::bindableDirection | ( | ) |
Definition at line 351 of file qtimeline.cpp.
QBindable< int > QTimeLine::bindableDuration | ( | ) |
Definition at line 388 of file qtimeline.cpp.
QBindable< QEasingCurve > QTimeLine::bindableEasingCurve | ( | ) |
Definition at line 510 of file qtimeline.cpp.
QBindable< int > QTimeLine::bindableLoopCount | ( | ) |
Definition at line 314 of file qtimeline.cpp.
QBindable< int > QTimeLine::bindableUpdateInterval | ( | ) |
Definition at line 481 of file qtimeline.cpp.
int QTimeLine::currentFrame | ( | ) | const |
Returns the frame corresponding to the current time.
Definition at line 550 of file qtimeline.cpp.
int QTimeLine::currentTime | ( | ) | const |
Definition at line 531 of file qtimeline.cpp.
qreal QTimeLine::currentValue | ( | ) | const |
Returns the value corresponding to the current time.
Definition at line 561 of file qtimeline.cpp.
QTimeLine::Direction QTimeLine::direction | ( | ) | const |
Definition at line 334 of file qtimeline.cpp.
int QTimeLine::duration | ( | ) | const |
Definition at line 369 of file qtimeline.cpp.
QEasingCurve QTimeLine::easingCurve | ( | ) | const |
Definition at line 498 of file qtimeline.cpp.
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).
Definition at line 424 of file qtimeline.cpp.
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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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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.
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().
Definition at line 574 of file qtimeline.cpp.
int QTimeLine::loopCount | ( | ) | const |
Definition at line 302 of file qtimeline.cpp.
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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.
Definition at line 642 of file qtimeline.cpp.
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slot |
Definition at line 536 of file qtimeline.cpp.
Definition at line 339 of file qtimeline.cpp.
void QTimeLine::setDuration | ( | int | duration | ) |
Definition at line 374 of file qtimeline.cpp.
void QTimeLine::setEasingCurve | ( | const QEasingCurve & | curve | ) |
Definition at line 504 of file qtimeline.cpp.
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.
Definition at line 436 of file qtimeline.cpp.
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.
Definition at line 453 of file qtimeline.cpp.
void QTimeLine::setLoopCount | ( | int | count | ) |
Definition at line 308 of file qtimeline.cpp.
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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.
Definition at line 675 of file qtimeline.cpp.
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.
Definition at line 412 of file qtimeline.cpp.
void QTimeLine::setUpdateInterval | ( | int | interval | ) |
Definition at line 476 of file qtimeline.cpp.
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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.
Definition at line 614 of file qtimeline.cpp.
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).
Definition at line 400 of file qtimeline.cpp.
QTimeLine::State QTimeLine::state | ( | ) | const |
Returns the state of the timeline.
Definition at line 288 of file qtimeline.cpp.
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signal |
This signal is emitted whenever QTimeLine's state changes.
The new state is newState.
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slot |
Stops the timeline, causing QTimeLine to enter NotRunning state.
Definition at line 660 of file qtimeline.cpp.
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overrideprotectedvirtual |
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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.
Definition at line 703 of file qtimeline.cpp.
int QTimeLine::updateInterval | ( | ) | const |
Definition at line 471 of file qtimeline.cpp.
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
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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.
Definition at line 592 of file qtimeline.cpp.
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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().
By default, this property contains a value of 0.
Definition at line 24 of file qtimeline.h.
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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 25 of file qtimeline.h.
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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.
Definition at line 21 of file qtimeline.h.
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readwrite |
Specifies the easing curve that the timeline will use. If valueForTime() is reimplemented, this value is ignored.
Definition at line 27 of file qtimeline.h.
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readwrite |
the number of times the timeline should loop before it's finished.
A loop count of 0 means that the timeline will loop forever.
By default, this property contains a value of 1.
Definition at line 26 of file qtimeline.h.
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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 22 of file qtimeline.h.