Long live Qt 4.5!

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+/****************************************************************************
+**
+** Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).
+** Contact: Qt Software Information (qt-info@nokia.com)
+**
+** This file is part of the QtCore module of the Qt Toolkit.
+**
+** $QT_BEGIN_LICENSE:LGPL$
+** No Commercial Usage
+** This file contains pre-release code and may not be distributed.
+** You may use this file in accordance with the terms and conditions
+** contained in the either Technology Preview License Agreement or the
+** Beta Release License Agreement.
+**
+** GNU Lesser General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU Lesser
+** General Public License version 2.1 as published by the Free Software
+** Foundation and appearing in the file LICENSE.LGPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU Lesser General Public License version 2.1 requirements
+** will be met: http://www.gnu.org/licenses/old-licenses/lgpl-2.1.html.
+**
+** In addition, as a special exception, Nokia gives you certain
+** additional rights. These rights are described in the Nokia Qt LGPL
+** Exception version 1.0, included in the file LGPL_EXCEPTION.txt in this
+** package.
+**
+** GNU General Public License Usage
+** Alternatively, this file may be used under the terms of the GNU
+** General Public License version 3.0 as published by the Free Software
+** Foundation and appearing in the file LICENSE.GPL included in the
+** packaging of this file.  Please review the following information to
+** ensure the GNU General Public License version 3.0 requirements will be
+** met: http://www.gnu.org/copyleft/gpl.html.
+**
+** If you are unsure which license is appropriate for your use, please
+** contact the sales department at qt-sales@nokia.com.
+** $QT_END_LICENSE$
+**
+****************************************************************************/
+
+#include "qtimeline.h"
+
+#include <private/qobject_p.h>
+#include <QtCore/qdatetime.h>
+#include <QtCore/qcoreevent.h>
+#include <QtCore/qmath.h>
+
+QT_BEGIN_NAMESPACE
+
+static const qreal pi = qreal(3.14159265359);
+static const qreal halfPi = pi / qreal(2.0);
+
+
+static inline qreal qt_sinProgress(qreal value)
+{
+    return qSin((value * pi) - halfPi) / 2 + qreal(0.5);
+}
+
+static inline qreal qt_smoothBeginEndMixFactor(qreal value)
+{
+    return qMin(qMax(1 - value * 2 + qreal(0.3), qreal(0.0)), qreal(1.0));
+}
+
+class QTimeLinePrivate : public QObjectPrivate
+{
+    Q_DECLARE_PUBLIC(QTimeLine)
+public:
+    inline QTimeLinePrivate()
+        : startTime(0), duration(1000), startFrame(0), endFrame(0),
+          updateInterval(1000 / 25),
+          totalLoopCount(1), currentLoopCount(0), currentTime(0), timerId(0),
+          direction(QTimeLine::Forward), curveShape(QTimeLine::EaseInOutCurve),
+          state(QTimeLine::NotRunning)
+    { }
+
+    int startTime;
+    int duration;
+    int startFrame;
+    int endFrame;
+    int updateInterval;
+    int totalLoopCount;
+    int currentLoopCount;
+
+    int currentTime;
+    int elapsedTime;
+    int timerId;
+    QTime timer;
+
+    QTimeLine::Direction direction;
+    QTimeLine::CurveShape curveShape;
+    QTimeLine::State state;
+    inline void setState(QTimeLine::State newState)
+    {
+        Q_Q(QTimeLine);
+        if (newState != state)
+            emit q->stateChanged(state = newState);
+    }
+
+    void setCurrentTime(int msecs);
+};
+
+/*!
+    \internal
+*/
+void QTimeLinePrivate::setCurrentTime(int msecs)
+{
+    Q_Q(QTimeLine);
+
+    qreal lastValue = q->currentValue();
+    int lastFrame = q->currentFrame();
+
+    // Determine if we are looping.
+    int elapsed = (direction == QTimeLine::Backward) ? (-msecs +  duration) : msecs;
+    int loopCount = elapsed / duration;
+
+    bool looping = (loopCount != currentLoopCount);
+#ifdef QTIMELINE_DEBUG
+    qDebug() << "QTimeLinePrivate::setCurrentTime:" << msecs << duration << "with loopCount" << loopCount
+             << "currentLoopCount" << currentLoopCount
+             << "looping" << looping;
+#endif
+    if (looping)
+        currentLoopCount = loopCount;
+
+    // Normalize msecs to be between 0 and duration, inclusive.
+    currentTime = elapsed % duration;
+    if (direction == QTimeLine::Backward)
+        currentTime = duration - currentTime;
+
+    // Check if we have reached the end of loopcount.
+    bool finished = false;
+    if (totalLoopCount && currentLoopCount >= totalLoopCount) {
+        finished = true;
+        currentTime = (direction == QTimeLine::Backward) ? 0 : duration;
+        currentLoopCount = totalLoopCount - 1;
+    }
+
+    int currentFrame = q->frameForTime(currentTime);
+#ifdef QTIMELINE_DEBUG
+    qDebug() << "QTimeLinePrivate::setCurrentTime: frameForTime" << currentTime << currentFrame;
+#endif
+    if (lastValue != q->currentValue())
+        emit q->valueChanged(q->currentValue());
+    if (lastFrame != currentFrame) {
+        const int transitionframe = (direction == QTimeLine::Forward ? endFrame : startFrame);
+        if (looping && !finished && transitionframe != currentFrame) {
+#ifdef QTIMELINE_DEBUG
+            qDebug() << "QTimeLinePrivate::setCurrentTime: transitionframe";
+#endif
+            emit q->frameChanged(transitionframe);
+        }
+#ifdef QTIMELINE_DEBUG
+        else {
+            QByteArray reason;
+            if (!looping)
+                reason += " not looping";
+            if (finished) {
+                if (!reason.isEmpty())
+                    reason += " and";
+                reason += " finished";
+            }
+            if (transitionframe == currentFrame) {
+                if (!reason.isEmpty())
+                    reason += " and";
+                reason += " transitionframe is equal to currentFrame: " + QByteArray::number(currentFrame);
+            }
+            qDebug("QTimeLinePrivate::setCurrentTime: not transitionframe because %s",  reason.constData());
+        }
+#endif
+        emit q->frameChanged(currentFrame);
+    }
+    if (finished && state == QTimeLine::Running) {
+        q->stop();
+        emit q->finished();
+    }
+}
+
+/*!
+    \class QTimeLine
+    \brief The QTimeLine class provides a timeline for controlling animations.
+    \since 4.2
+    \ingroup multimedia
+
+    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 (e.g., 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:
+
+    \snippet doc/src/snippets/code/src_corelib_tools_qtimeline.cpp 0
+
+    You can also use QTimeLine with the
+    \l{Graphics View}{Graphics View framework} for
+    animations. The QGraphicsItemAnimation class implements animation
+    of \l{QGraphicsItem}{QGraphicsItems} with a timeline.
+
+    By default the timeline runs once, from the beginning and towards the 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 \e 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
+    setCurveShape(). By default, QTimeLine uses the EaseInOut curve shape,
+    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 curveShape property is ignored.
+
+    \sa QProgressBar, QProgressDialog, QGraphicsItemAnimation
+*/
+
+/*!
+    \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.
+
+    \sa state(), stateChanged()
+*/
+
+/*!
+    \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).
+
+    \sa setDirection()
+*/
+
+/*!
+    \enum QTimeLine::CurveShape
+
+    This enum describes the default shape of QTimeLine's value curve. The
+    default, shape is EaseInOutCurve. The curve defines the relation
+    between the value and the timeline.
+
+    \value EaseInCurve The value starts growing slowly, then increases in speed.
+    \value EaseOutCurve The value starts growing steadily, then ends slowly.
+    \value EaseInOutCurve The value starts growing slowly, then runs steadily, then grows slowly again.
+    \value LinearCurve The value grows linearly (e.g., if the duration is 1000 ms,
+           the value at time 500 ms is 0.5).
+    \value SineCurve The value grows sinusoidally.
+    \value CosineCurve The value grows cosinusoidally.
+
+    \sa setCurveShape()
+*/
+
+/*!
+    \fn QTimeLine::valueChanged(qreal value)
+
+    QTimeLine emits this signal at regular intervals when in \l Running state,
+    but only if the current value changes. \a value is the current value. \a value is
+    a number between 0.0 and 1.0
+
+    \sa QTimeLine::setDuration(), QTimeLine::valueForTime(), QTimeLine::updateInterval
+*/
+
+/*!
+    \fn QTimeLine::frameChanged(int frame)
+
+    QTimeLine emits this signal at regular intervals when in \l Running state,
+    but only if the current frame changes. \a frame is the current frame number.
+
+    \sa QTimeLine::setFrameRange(), QTimeLine::updateInterval
+*/
+
+/*!
+    \fn QTimeLine::stateChanged(QTimeLine::State newState)
+
+    This signal is emitted whenever QTimeLine's state changes. The new state
+    is \a newState.
+*/
+
+/*!
+    \fn QTimeLine::finished()
+
+    This signal is emitted when QTimeLine finishes (i.e., reaches the end of
+    its time line), and does not loop.
+*/
+
+/*!
+    Constructs a timeline with a duration of \a duration milliseconds. \a
+    parent is passed to QObject's constructor. The default duration is 1000
+    milliseconds.
+ */
+QTimeLine::QTimeLine(int duration, QObject *parent)
+    : QObject(*new QTimeLinePrivate, parent)
+{
+    setDuration(duration);
+}
+
+/*!
+    Destroys the timeline.
+ */
+QTimeLine::~QTimeLine()
+{
+    Q_D(QTimeLine);
+
+    if (d->state == Running)
+        stop();
+}
+
+/*!
+    Returns the state of the timeline.
+
+    \sa start(), setPaused(), stop()
+*/
+QTimeLine::State QTimeLine::state() const
+{
+    Q_D(const QTimeLine);
+    return d->state;
+}
+
+/*!
+    \property QTimeLine::loopCount
+    \brief 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.
+*/
+int QTimeLine::loopCount() const
+{
+    Q_D(const QTimeLine);
+    return d->totalLoopCount;
+}
+void QTimeLine::setLoopCount(int count)
+{
+    Q_D(QTimeLine);
+    d->totalLoopCount = count;
+}
+
+/*!
+    \property QTimeLine::direction
+    \brief 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.
+
+    By default, this property is set to \l Forward.
+*/
+QTimeLine::Direction QTimeLine::direction() const
+{
+    Q_D(const QTimeLine);
+    return d->direction;
+}
+void QTimeLine::setDirection(Direction direction)
+{
+    Q_D(QTimeLine);
+    d->direction = direction;
+    d->startTime = d->currentTime;
+    d->timer.start();
+}
+
+/*!
+    \property QTimeLine::duration
+    \brief 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.
+*/
+int QTimeLine::duration() const
+{
+    Q_D(const QTimeLine);
+    return d->duration;
+}
+void QTimeLine::setDuration(int duration)
+{
+    Q_D(QTimeLine);
+    if (duration <= 0) {
+        qWarning("QTimeLine::setDuration: cannot set duration <= 0");
+        return;
+    }
+    d->duration = duration;
+}
+
+/*!
+    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).
+
+    \sa setStartFrame(), setFrameRange()
+*/
+int QTimeLine::startFrame() const
+{
+    Q_D(const QTimeLine);
+    return d->startFrame;
+}
+
+/*!
+    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 \a frame.
+
+    \sa startFrame(), endFrame(), setFrameRange()
+*/
+void QTimeLine::setStartFrame(int frame)
+{
+    Q_D(QTimeLine);
+    d->startFrame = frame;
+}
+
+/*!
+    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).
+
+    \sa setEndFrame(), setFrameRange()
+*/
+int QTimeLine::endFrame() const
+{
+    Q_D(const QTimeLine);
+    return d->endFrame;
+}
+
+/*!
+    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 \a frame.
+
+    \sa endFrame(), startFrame(), setFrameRange()
+*/
+void QTimeLine::setEndFrame(int frame)
+{
+    Q_D(QTimeLine);
+    d->endFrame = frame;
+}
+
+/*!
+    Sets the timeline's frame counter to start at \a startFrame, and end and
+    \a 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.
+
+    \sa startFrame(), endFrame(), start(), currentFrame()
+*/
+void QTimeLine::setFrameRange(int startFrame, int endFrame)
+{
+    Q_D(QTimeLine);
+    d->startFrame = startFrame;
+    d->endFrame = endFrame;
+}
+
+/*!
+    \property QTimeLine::updateInterval
+    \brief 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.
+*/
+int QTimeLine::updateInterval() const
+{
+    Q_D(const QTimeLine);
+    return d->updateInterval;
+}
+void QTimeLine::setUpdateInterval(int interval)
+{
+    Q_D(QTimeLine);
+    d->updateInterval = interval;
+}
+
+/*!
+    \property QTimeLine::curveShape
+    \brief the shape of the timeline curve.
+
+    The curve shape describes the relation between the time and value for the
+    base implementation of valueForTime().
+
+    If you have reimplemented valueForTime(), this value is ignored.
+
+    By default, this property is set to \l EaseInOutCurve.
+
+    \sa valueForTime()
+*/
+QTimeLine::CurveShape QTimeLine::curveShape() const
+{
+    Q_D(const QTimeLine);
+    return d->curveShape;
+}
+void QTimeLine::setCurveShape(CurveShape shape)
+{
+    Q_D(QTimeLine);
+    d->curveShape = shape;
+}
+
+/*!
+    \property QTimeLine::currentTime
+    \brief 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.
+*/
+int QTimeLine::currentTime() const
+{
+    Q_D(const QTimeLine);
+    return d->currentTime;
+}
+void QTimeLine::setCurrentTime(int msec)
+{
+    Q_D(QTimeLine);
+    d->startTime = 0;
+    d->currentLoopCount = 0;
+    d->timer.restart();
+    d->setCurrentTime(msec);
+}
+
+/*!
+    Returns the frame corresponding to the current time.
+
+    \sa currentTime(), frameForTime(), setFrameRange()
+*/
+int QTimeLine::currentFrame() const
+{
+    Q_D(const QTimeLine);
+    return frameForTime(d->currentTime);
+}
+
+/*!
+    Returns the value corresponding to the current time.
+
+    \sa valueForTime(), currentFrame()
+*/
+qreal QTimeLine::currentValue() const
+{
+    Q_D(const QTimeLine);
+    return valueForTime(d->currentTime);
+}
+
+/*!
+    Returns the frame corresponding to the time \a msec. This value is
+    calculated using a linear interpolation of the start and end frame, based
+    on the value returned by valueForTime().
+
+    \sa valueForTime(), setFrameRange()
+*/
+int QTimeLine::frameForTime(int msec) const
+{
+    Q_D(const QTimeLine);
+    if (d->direction == Forward)
+        return d->startFrame + int((d->endFrame - d->startFrame) * valueForTime(msec));
+    return d->startFrame + qCeil((d->endFrame - d->startFrame) * valueForTime(msec));
+}
+
+/*!
+    Returns the timeline value for the time \a msec. The returned value, which
+    varies depending on the curve shape, is always between 0 and 1. If \a msec
+    is 0, the default implementation always returns 0.
+
+    Reimplement this function to provide a custom curve shape for your
+    timeline.
+
+    \sa CurveShape, frameForTime()
+*/
+qreal QTimeLine::valueForTime(int msec) const
+{
+    Q_D(const QTimeLine);
+    msec = qMin(qMax(msec, 0), d->duration);
+
+    // Simple linear interpolation
+    qreal value = msec / qreal(d->duration);
+
+    switch (d->curveShape) {
+    case EaseInOutCurve:
+        value = qt_sinProgress(value);
+        break;
+        // SmoothBegin blends Smooth and Linear Interpolation.
+        // Progress 0 - 0.3      : Smooth only
+        // Progress 0.3 - ~ 0.5  : Mix of Smooth and Linear
+        // Progress ~ 0.5  - 1   : Linear only
+    case EaseInCurve: {
+        const qreal sinProgress = qt_sinProgress(value);
+        const qreal linearProgress = value;
+        const qreal mix = qt_smoothBeginEndMixFactor(value);
+        value = sinProgress * mix + linearProgress * (1 - mix);
+        break;
+    }
+    case EaseOutCurve: {
+        const qreal sinProgress = qt_sinProgress(value);
+        const qreal linearProgress = value;
+        const qreal mix = qt_smoothBeginEndMixFactor(1 - value);
+        value = sinProgress * mix + linearProgress * (1 - mix);
+        break;
+    }
+    case SineCurve:
+        value = (qSin(((msec * pi * 2) / d->duration) - pi/2) + 1) / 2;
+        break;
+    case CosineCurve:
+        value = (qCos(((msec * pi * 2) / d->duration) - pi/2) + 1) / 2;
+        break;
+    default:
+        break;
+    }
+
+    return value;
+}
+
+/*!
+    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().
+
+    If you want to resume a stopped timeline without restarting, you can call
+    resume() instead.
+
+    \sa resume(), updateInterval(), frameChanged(), valueChanged()
+*/
+void QTimeLine::start()
+{
+    Q_D(QTimeLine);
+    if (d->timerId) {
+        qWarning("QTimeLine::start: already running");
+        return;
+    }
+    int curTime = d->currentTime;
+    if (curTime == d->duration && d->direction == Forward)
+        curTime = 0;
+    else if (curTime == 0 && d->direction == Backward)
+        curTime = d->duration;
+    d->timerId = startTimer(d->updateInterval);
+    d->startTime = curTime;
+    d->currentLoopCount = 0;
+    d->timer.start();
+    d->setState(Running);
+    d->setCurrentTime(curTime);
+}
+
+/*!
+    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
+    is resumes.
+
+    \sa start(), updateInterval(), frameChanged(), valueChanged()
+*/
+void QTimeLine::resume()
+{
+    Q_D(QTimeLine);
+    if (d->timerId) {
+        qWarning("QTimeLine::resume: already running");
+        return;
+    }
+    d->timerId = startTimer(d->updateInterval);
+    d->startTime = d->currentTime;
+    d->timer.start();
+    d->setState(Running);
+}
+
+/*!
+    Stops the timeline, causing QTimeLine to enter NotRunning state.
+
+    \sa start()
+*/
+void QTimeLine::stop()
+{
+    Q_D(QTimeLine);
+    if (d->timerId)
+        killTimer(d->timerId);
+    d->setState(NotRunning);
+    d->timerId = 0;
+}
+
+/*!
+    If \a 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 \a paused is false, the timeline is resumed
+    and continues where it left.
+
+    \sa state(), start()
+*/
+void QTimeLine::setPaused(bool paused)
+{
+    Q_D(QTimeLine);
+    if (d->state == NotRunning) {
+        qWarning("QTimeLine::setPaused: Not running");
+        return;
+    }
+    if (paused && d->state != Paused) {
+        d->startTime = d->currentTime;
+        killTimer(d->timerId);
+        d->timerId = 0;
+        d->setState(Paused);
+    } else if (!paused && d->state == Paused) {
+        d->timerId = startTimer(d->updateInterval);
+        d->setState(Running);
+    }
+}
+
+/*!
+    Toggles the direction of the timeline. If the direction was Forward, it
+    becomes Backward, and vice verca.
+
+    \sa setDirection()
+*/
+void QTimeLine::toggleDirection()
+{
+    Q_D(QTimeLine);
+    setDirection(d->direction == Forward ? Backward : Forward);
+}
+
+/*!
+    \reimp
+*/
+void QTimeLine::timerEvent(QTimerEvent *event)
+{
+    Q_D(QTimeLine);
+    if (event->timerId() != d->timerId) {
+        event->ignore();
+        return;
+    }
+    event->accept();
+
+    if (d->direction == Forward) {
+        d->setCurrentTime(d->startTime + d->timer.elapsed());
+    } else {
+        d->setCurrentTime(d->startTime - d->timer.elapsed());
+    }
+}
+
+QT_END_NAMESPACE