QTimeLine Class

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

List of all members, including inherited members

Public Types

Public Functions

Public Slots

Signals

Reimplemented Protected Functions

Detailed Description

A QTimeLine runs for duration() milliseconds and emits valueChanged() with the progress, shaped by easingCurve(), every updateInterval() milliseconds. With a frame range it also emits frameChanged():

QTimeLine timeLine(1000);
timeLine.setFrameRange(0, 100);
QObject::connect(&timeLine, &QTimeLine::frameChanged, progressBar, &QProgressBar::setValue);
timeLine.start();

See also QEasingCurve and QTimer.

Differences from Qt

Member Type Documentation

enum QTimeLine::Direction

enum QTimeLine::State

Member Function Documentation

[explicit] QTimeLine::QTimeLine(int duration = 1000, QObject *parent = nullptr)

Constructs a time line that runs for duration milliseconds, with the given parent. The frame range is 0 to 0 and the easing curve QEasingCurve::InOutSine.

[override] QTimeLine::~QTimeLine()

Destroys the time line, stopping it first.

int QTimeLine::currentFrame() const

Returns the frame for the current time.

int QTimeLine::currentTime() const

Returns the current time of the time line in milliseconds, from 0 to duration().

qreal QTimeLine::currentValue() const

Returns the value for the current time.

Direction QTimeLine::direction() const

Returns the direction of the time line.

See also setDirection() and toggleDirection().

int QTimeLine::duration() const

Returns the duration of one loop in milliseconds.

QEasingCurve QTimeLine::easingCurve() const

Returns the easing curve that shapes the value of the time line.

This function was introduced in 4.6.

int QTimeLine::endFrame() const

Returns the last frame of the frame range.

[signal] void QTimeLine::finished()

This signal is emitted when the time line finishes, that is, when it reaches its end after the last loop. It is not emitted by stop().

[signal] void QTimeLine::frameChanged(int frame)

This signal is emitted when the current frame changes, with the new frame.

See also setFrameRange().

int QTimeLine::frameForTime(int msec) const

Returns the frame for the time msec: the frame range scaled by valueForTime(), rounded toward the start frame when running forward and away from it when running backward.

int QTimeLine::loopCount() const

Returns the number of times the time line runs before it finishes, 0 meaning forever. The default is 1.

See also setLoopCount().

[slot] void QTimeLine::resume()

Resumes the time line from its current time. Does nothing, with a warning, if it is already running.

[slot] void QTimeLine::setCurrentTime(int msec)

Sets the current time to msec, measured from the start of the current loop in the forward direction, and emits valueChanged() and frameChanged() as needed. A time past the end of the loop moves on to the next loops; after the last loop the time line stops and emits finished().

void QTimeLine::setDirection(Direction direction)

Sets the direction of the time line to direction. A running time line continues from its current time in the new direction.

void QTimeLine::setDuration(int duration)

Sets the duration of one loop to duration milliseconds, which must be positive.

void QTimeLine::setEasingCurve(const QEasingCurve &curve)

Sets the easing curve to curve.

This function was introduced in 4.6.

void QTimeLine::setEndFrame(int frame)

Sets the last frame of the frame range to frame.

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

Sets the frame range to startFrame to endFrame.

See also frameForTime() and frameChanged().

void QTimeLine::setLoopCount(int count)

Sets the number of loops to count; 0 makes the time line loop forever.

[slot] void QTimeLine::setPaused(bool paused)

Pauses the time line if paused is true, or resumes it if paused is false and it is paused.

void QTimeLine::setStartFrame(int frame)

Sets the first frame of the frame range to frame.

void QTimeLine::setUpdateInterval(int interval)

Sets the update interval to interval milliseconds. A running time line uses it from the next start or resume.

[slot] void QTimeLine::start()

Starts the time line from its beginning (from duration() when running backward). Does nothing, with a warning, if it is already running.

See also resume() and stop().

int QTimeLine::startFrame() const

Returns the first frame of the frame range.

State QTimeLine::state() const

Returns the state of the time line.

[signal] void QTimeLine::stateChanged(QTimeLine::State newState)

This signal is emitted when the state of the time line changes, with the new state newState.

[slot] void QTimeLine::stop()

Stops the time line, keeping its current time. finished() is not emitted.

[override, protected] void QTimeLine::timerEvent(QTimerEvent *event)

Reimplements QObject::timerEvent().

[slot] void QTimeLine::toggleDirection()

Reverses the direction of the time line.

See also setDirection().

int QTimeLine::updateInterval() const

Returns the interval in milliseconds between updates while the time line runs. The default is 40, 25 updates a second.

[signal] void QTimeLine::valueChanged(qreal value)

This signal is emitted at regular intervals while the time line runs, and when the current time changes, with the new value.

See also valueForTime() and updateInterval().

[virtual] qreal QTimeLine::valueForTime(int msec) const

Returns the value for the time msec: the easing curve applied to the progress msec / duration(), clamped to the range 0 to 1. Reimplement it for a custom shape.