path: root/src/corelib/animation/qabstractanimation.cpp

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/*!
    \class QAbstractAnimation
    \ingroup animation
    \brief The QAbstractAnimation class provides an abstract base class for animations.
    \since 4.5
    \preliminary

    The class defines the functions for the functionality shared
    between all animations. By inheriting this class, you can create
    custom animations that plug into the rest of the animation
    framework.

    
    
    QAbstractAnimation provides an interface for the current time and
    duration, the loop count, and the state of an animation. These properties
    define the base functionality common to all animations in Qt. The virtual
    duration() function returns the local duration of the animation; i.e., for
    how long the animation should update the current time before
    looping. Subclasses can implement this function differently; for example,
    QVariantAnimation returns the duration of a simple animated property, whereas
    QAnimationGroup returns the duration of a set or sequence of
    animations. You can also set a loop count by calling setLoopCount(); a
    loop count of 2 will let the animation run twice (the default value is
    1).

    Like QTimeLine, QAbstractAnimation also provides an interface for starting
    and stopping an animation, and for tracking its progress. You can call the
    start() slot to start the animation. When the animation starts, the
    stateChanged() signal is emitted, and state() returns Running. If you call the
    stop() slot, the stateChanged() signal is emitted, and state() returns
    Stopped. If you call the pause() slot, the stateChanged() signal is emitted
    and state() returns Paused. If the animation reaches the end, the finished()
    signal is emitted. You can check the current state by calling state().

    QAbstractAnimation provides two functions that are pure virtual, and must
    be reimplemented in a subclass: duration(), and updateCurrentTime(). The
    duration() function lets you report a duration for the animation (a return
    value of -1 signals that the animation runs forever until explicitly
    stopped). The current time is delivered by the framework through calls to
    updateCurrentTime(). By reimplementing this function, you can track the
    animation progress and update your target objects accordingly. By
    reimplementing updateState(), you can track the animation's state
    changes, which is particularily useful for animations that are not driven
    by time.

    \omit
    If you want to create an animation, you should look at the two subclasses,
    QVariantAnimation and QAnimationGroup, instead.
    \endomit

    \sa QVariantAnimation, QAnimationGroup, {The Animation Framework}
*/

/*!
    \enum QAbstractAnimation::DeletionPolicy

    \value KeepWhenStopped The animation will not be deleted when stopped.
    \value DeleteWhenStopped The animation will be automatically deleted when
    stopped.
*/

/*!
    \fn QAbstractAnimation::finished()

    QAbstractAnimation emits this signal after the animation has stopped and
    has reached the end.

    This signal is emitted after stateChanged().

    \sa stateChanged()
*/

/*!
    \fn QAbstractAnimation::stateChanged(QAbstractAnimation::State oldState, QAbstractAnimation::State newState)

    QAbstractAnimation emits this signal whenever the state of the animation has
    changed from \a oldState to \a newState. This signal is emitted after the virtual
    updateState() function is called.

    \sa updateState()
*/

/*!
    \fn QAbstractAnimation::currentLoopChanged(int currentLoop)

    QAbstractAnimation emits this signal whenever the current loop
    changes. \a currentLoop is the current loop.

    \sa currentLoop(), loopCount()
*/

/*!
    \fn QAbstractAnimation::directionChanged(QAbstractAnimation::Direction newDirection);

    QAbstractAnimation emits this signal whenever the direction has been
    changed. \a newDirection is the new direction.

    \sa direction
*/

#ifndef QT_NO_ANIMATION

#include "qabstractanimation.h"
#include "qanimationgroup.h"
#include <QtCore/qdebug.h>

#include "qabstractanimation_p.h"

#include <QtCore/qmath.h>
#include <QtCore/qthreadstorage.h>
#include <QtCore/qcoreevent.h>
#include <QtCore/qpointer.h>

#define TIMER_INTERVAL 16

QT_BEGIN_NAMESPACE

Q_GLOBAL_STATIC(QThreadStorage<QUnifiedTimer *>, unifiedTimer);

QUnifiedTimer::QUnifiedTimer() : QObject(), lastTick(0)
{
}

QUnifiedTimer *QUnifiedTimer::instance()
{
    QUnifiedTimer *inst;
    if (!unifiedTimer()->hasLocalData()) {
        inst = new QUnifiedTimer;
        unifiedTimer()->setLocalData(inst);
    } else {
        inst = unifiedTimer()->localData();
    }
    return inst;
}

void QUnifiedTimer::updateRecentlyStartedAnimations()
{
    if (animationsToStart.isEmpty())
        return;

    animations += animationsToStart;
    updateTimer(); //we make sure we start the timer there

    animationsToStart.clear();
}

void QUnifiedTimer::timerEvent(QTimerEvent *event)
{
    //this is simply the time we last received a tick
    int oldLastTick = lastTick;
    if (time.isValid())
        lastTick = time.elapsed();

    //we transfer the waiting animations into the "really running" state
    updateRecentlyStartedAnimations();

    if (event->timerId() == startStopAnimationTimer.timerId()) {
        startStopAnimationTimer.stop();
        if (animations.isEmpty()) {
            animationTimer.stop();
            time = QTime();
        } else {
            animationTimer.start(TIMER_INTERVAL, this);
            lastTick = 0;
            time.start();
        }
    } else if (event->timerId() == animationTimer.timerId()) {
        const int delta = lastTick - oldLastTick;
        for (int i = 0; i < animations.count(); ++i) {
            QAbstractAnimation *animation = animations.at(i);
            int elapsed = QAbstractAnimationPrivate::get(animation)->totalCurrentTime
                + (animation->direction() == QAbstractAnimation::Forward ? delta : -delta);
            animation->setCurrentTime(elapsed);
        }
    }
}

void QUnifiedTimer::updateTimer()
{
    //we delay the call to start and stop for the animation timer so that if you
    //stop and start animations in batch you don't stop/start the timer too often.
    if (!startStopAnimationTimer.isActive())
        startStopAnimationTimer.start(0, this); // we delay the actual start of the animation
}

void QUnifiedTimer::registerAnimation(QAbstractAnimation *animation)
{
    if (animations.contains(animation) ||animationsToStart.contains(animation))
        return;
    animationsToStart << animation;
    updateTimer();
}

void QUnifiedTimer::unregisterAnimation(QAbstractAnimation *animation)
{
    animations.removeAll(animation);
    animationsToStart.removeAll(animation);
    updateTimer();
}


void QAbstractAnimationPrivate::setState(QAbstractAnimation::State newState)
{
    Q_Q(QAbstractAnimation);
    if (state == newState)
        return;

    QAbstractAnimation::State oldState = state;
    int oldCurrentTime = currentTime;
    int oldCurrentLoop = currentLoop;
    QAbstractAnimation::Direction oldDirection = direction;

    state = newState;

    QPointer<QAbstractAnimation> guard(q);

    guard->updateState(oldState, newState);

    //this is to be safe if updateState changes the state
    if (state == oldState)
        return;

    // Notify state change
    if (guard)
        emit guard->stateChanged(oldState, newState);

    // Enter running state.
    switch (state)
    {
    case QAbstractAnimation::Paused:
    case QAbstractAnimation::Running:
        {
            // Rewind
            if (oldState == QAbstractAnimation::Stopped) {
                if (guard) {
                    if (direction == QAbstractAnimation::Forward)
                        q->setCurrentTime(0);
                    else
                        q->setCurrentTime(loopCount == -1 ? q->duration() : q->totalDuration());
                }

                // Check if the setCurrentTime() function called stop().
                // This can happen for a 0-duration animation
                if (state == QAbstractAnimation::Stopped)
                    return;
            }

            // Register timer if our parent is not running.
            if (state == QAbstractAnimation::Running && guard) {
                if (!group || group->state() == QAbstractAnimation::Stopped) {
                    QUnifiedTimer::instance()->registerAnimation(q);
                }
            } else {
                //new state is paused
                QUnifiedTimer::instance()->unregisterAnimation(q);
            }
        }
        break;
    case QAbstractAnimation::Stopped:
        // Leave running state.
        int dura = q->duration();
        if (deleteWhenStopped && guard)
            q->deleteLater();

        QUnifiedTimer::instance()->unregisterAnimation(q);

        if (dura == -1 || loopCount < 0
            || (oldDirection == QAbstractAnimation::Forward && (oldCurrentTime * (oldCurrentLoop + 1)) == (dura * loopCount))
            || (oldDirection == QAbstractAnimation::Backward && oldCurrentTime == 0)) {
                if (guard)
                    emit q->finished();
        }
        break;
    }

}

/*!
    Constructs the QAbstractAnimation base class, and passes \a parent to
    QObject's constructor.

    \sa QVariantAnimation, QAnimationGroup
*/
#ifdef QT_EXPERIMENTAL_SOLUTION
QAbstractAnimation::QAbstractAnimation(QObject *parent)
    : d_ptr(new QAbstractAnimationPrivate)
{
    // Allow auto-add on reparent
    setParent(parent);
    d_ptr->q_ptr = this;
}
#else
QAbstractAnimation::QAbstractAnimation(QObject *parent)
    : QObject(*new QAbstractAnimationPrivate, 0)
{
    // Allow auto-add on reparent
    setParent(parent);
}
#endif

/*!
    \internal
*/
#ifdef QT_EXPERIMENTAL_SOLUTION
QAbstractAnimation::QAbstractAnimation(QAbstractAnimationPrivate &dd, QObject *parent)
    : d_ptr(&dd)
{
    // Allow auto-add on reparent
   setParent(parent);
   d_ptr->q_ptr = this;
}
#else
QAbstractAnimation::QAbstractAnimation(QAbstractAnimationPrivate &dd, QObject *parent)
    : QObject(dd, 0)
{
    // Allow auto-add on reparent
   setParent(parent);
}
#endif

/*!
    Stops the animation if it's running, then destroys the
    QAbstractAnimation. If the animation is part of a QAnimationGroup, it is
    automatically removed before it's destroyed.
*/
QAbstractAnimation::~QAbstractAnimation()
{
    Q_D(QAbstractAnimation);
    //we can't call stop here. Otherwise we get pure virtual calls
    if (d->state != Stopped) {
        QAbstractAnimation::State oldState = d->state;
        d->state = Stopped;
        emit stateChanged(oldState, d->state);
        QUnifiedTimer::instance()->unregisterAnimation(this);
    }
}

/*!
    \property QAbstractAnimation::state
    \brief state of the animation.

    This property describes the current state of the animation. When the
    animation state changes, QAbstractAnimation emits the stateChanged()
    signal.
*/
QAbstractAnimation::State QAbstractAnimation::state() const
{
    Q_D(const QAbstractAnimation);
    return d->state;
}

/*!
    If this animation is part of a QAnimationGroup, this function returns a
    pointer to the group; otherwise, it returns 0.

    \sa QAnimationGroup::addAnimation()
*/
QAnimationGroup *QAbstractAnimation::group() const
{
    Q_D(const QAbstractAnimation);
    return d->group;
}

/*!
    \enum QAbstractAnimation::State

    This enum describes the state of the animation.

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

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

    \value Running The animation is running. While control is in the event
    loop, QAbstractAnimation will update its current time at regular intervals,
    calling updateCurrentTime() when appropriate.

    \sa state(), stateChanged()
*/

/*!
    \enum QAbstractAnimation::Direction

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

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

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

    \sa direction
*/

/*!
    \property QAbstractAnimation::direction
    \brief the direction of the animation when it is in \l Running
    state.

    This direction indicates whether the time moves from 0 towards the
    animation 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.
*/
QAbstractAnimation::Direction QAbstractAnimation::direction() const
{
    Q_D(const QAbstractAnimation);
    return d->direction;
}
void QAbstractAnimation::setDirection(Direction direction)
{
    Q_D(QAbstractAnimation);
    if (d->direction == direction)
        return;

    d->direction = direction;
    if (state() == Stopped) {
        if (direction == Backward) {
            d->currentTime = duration();
            d->currentLoop = d->loopCount - 1;
        } else {
            d->currentTime = 0;
            d->currentLoop = 0;
        }
    }
    updateDirection(direction);
    emit directionChanged(direction);
}

/*!
    \property QAbstractAnimation::duration
    \brief the duration of the animation.

    If the duration is -1, it means that the duration is undefined.
    In this case, loopCount is ignored.
*/

/*!
    \property QAbstractAnimation::loopCount
    \brief the loop count of the animation

    This property describes the loop count of the animation as an integer.
    By default this value is 1, indicating that the animation
    should run once only, and then stop. By changing it you can let the
    animation loop several times. With a value of 0, the animation will not
    run at all, and with a value of -1, the animation will loop forever
    until stopped.
    It is not supported to have loop on an animation that has an undefined
    duration. It will only run once.
*/
int QAbstractAnimation::loopCount() const
{
    Q_D(const QAbstractAnimation);
    return d->loopCount;
}
void QAbstractAnimation::setLoopCount(int loopCount)
{
    Q_D(QAbstractAnimation);
    d->loopCount = loopCount;
}

/*!
    \property QAbstractAnimation::currentLoop
    \brief the current loop of the animation

    This property describes the current loop of the animation. By default,
    the animation's loop count is 1, and so the current loop will
    always be 0. If the loop count is 2 and the animation runs past its
    duration, it will automatically rewind and restart at current time 0, and
    current loop 1, and so on.

    When the current loop changes, QAbstractAnimation emits the
    currentLoopChanged() signal.
*/
int QAbstractAnimation::currentLoop() const
{
    Q_D(const QAbstractAnimation);
    return d->currentLoop;
}

/*!
    \fn virtual int QAbstractAnimation::duration() const = 0

    This pure virtual function returns the duration of the animation, and
    defines for how long QAbstractAnimation should update the current
    time. This duration is local, and does not include the loop count.

    A return value of -1 indicates that the animation has no defined duration;
    the animation should run forever until stopped. This is useful for
    animations that are not time driven, or where you cannot easily predict
    its duration (e.g., event driven audio playback in a game).

    If the animation is a parallel QAnimationGroup, the duration will be the longest
    duration of all its animations. If the animation is a sequential QAnimationGroup,
    the duration will be the sum of the duration of all its animations.
    \sa loopCount
*/

/*!
    Returns the total and effective duration of the animation, including the
    loop count.

    \sa duration(), currentTime
*/
int QAbstractAnimation::totalDuration() const
{
    Q_D(const QAbstractAnimation);
    if (d->loopCount < 0)
        return -1;
    int dura = duration();
    if (dura == -1)
        return -1;
    return dura * d->loopCount;
}

/*!
    \property QAbstractAnimation::currentTime
    \brief the current time and progress of the animation

    This property describes the animation's current time. You can change the
    current time by calling setCurrentTime, or you can call start() and let
    the animation run, setting the current time automatically as the animation
    progresses.

    The animation's current time starts at 0, and ends at duration(). If the
    animation's loopCount is larger than 1, the current time will rewind and
    start at 0 again for the consecutive loops. If the animation has a pause.
    currentTime will also include the duration of the pause.

    \sa loopCount
 */
int QAbstractAnimation::currentTime() const
{
    Q_D(const QAbstractAnimation);
    return d->currentTime;
}
void QAbstractAnimation::setCurrentTime(int msecs)
{
    Q_D(QAbstractAnimation);
    msecs = qMax(msecs, 0);

    // Calculate new time and loop.
    int dura = duration();
    int totalDura = (d->loopCount < 0 || dura == -1) ? -1 : dura * d->loopCount;
    if (totalDura != -1)
        msecs = qMin(totalDura, msecs);
    d->totalCurrentTime = msecs;

    // Update new values.
    int oldLoop = d->currentLoop;
    d->currentLoop = ((dura <= 0) ? 0 : (msecs / dura));
    if (d->currentLoop == d->loopCount) {
        //we're at the end
        d->currentTime = qMax(0, dura);
        d->currentLoop = qMax(0, d->loopCount - 1);
    } else {
        if (d->direction == Forward) {
            d->currentTime = (dura <= 0) ? msecs : (msecs % dura);
        } else {
            d->currentTime = (dura <= 0) ? msecs : ((msecs - 1) % dura) + 1;
            if (d->currentTime == dura)
                --d->currentLoop;
        }
    }

    updateCurrentTime(msecs);
    if (d->currentLoop != oldLoop)
        emit currentLoopChanged(d->currentLoop);

    // All animations are responsible for stopping the animation when their
    // own end state is reached; in this case the animation is time driven,
    // and has reached the end.
    if ((d->direction == Forward && d->totalCurrentTime == totalDura)
        || (d->direction == Backward && d->totalCurrentTime == 0)) {
        stop();
    }
}

/*!
    Starts the animation. The \a policy argument says whether or not the
    animation should be deleted when it's done. When the animation starts, the
    stateChanged() signal is emitted, and state() returns Running. When control
    reaches the event loop, the animation will run by itself, periodically
    calling updateCurrentTime() as the animation progresses.

    If the animation is currently stopped or has already reached the end,
    calling start() will rewind the animation and start again from the beginning.
    When the animation reaches the end, the animation will either stop, or
    if the loop level is more than 1, it will rewind and continue from the beginning.

    If the animation is already running, this function does nothing.

    \sa stop(), state()
*/
void QAbstractAnimation::start(DeletionPolicy policy)
{
    Q_D(QAbstractAnimation);
    if (d->state == Running)
        return;
    d->setState(Running);
    d->deleteWhenStopped = policy;
}

/*!
    Stops the animation. When the animation is stopped, it emits the stateChanged()
    signal, and state() returns Stopped. The current time is not changed.

    If the animation stops by itself after reaching the end (i.e.,
    currentTime() == duration() and currentLoop() > loopCount() - 1), the
    finished() signal is emitted.

    \sa start(), state()
 */
void QAbstractAnimation::stop()
{
    Q_D(QAbstractAnimation);

    d->setState(Stopped);
}

/*!
    Pauses the animation. When the animation is paused, state() returns Paused.
    The currenttime will remain unchanged until resume() or start() is called.
    If you want to continue from the current time, call resume().


    \sa start(), state(), resume()
 */
void QAbstractAnimation::pause()
{
    Q_D(QAbstractAnimation);
    if (d->state == Stopped) {
        qWarning("QAbstractAnimation::pause: Cannot pause a stopped animation");
        return;
    }

    d->setState(Paused);
}

/*!
    Resumes the animation after it was paused. When the animation is resumed,
    it emits the resumed() and stateChanged() signals. The currenttime is not
    changed.

    \sa start(), pause(), state()
 */
void QAbstractAnimation::resume()
{
    Q_D(QAbstractAnimation);
    if (d->state != Paused) {
        qWarning("QAbstractAnimation::resume: "
                 "Cannot resume an animation that is not paused");
        return;
    }

    d->setState(Running);
}

/*!
    \reimp
*/
bool QAbstractAnimation::event(QEvent *event)
{
    return QObject::event(event);
}

/*!
    \fn virtual void QAbstractAnimation::updateCurrentTime(int msecs) = 0;

    This pure virtual function is called every time the animation's current
    time changes. The \a msecs argument is the current time.

    \sa updateState()
*/

/*!
    This virtual function is called by QAbstractAnimation when the state
    of the animation is changed from \a oldState to \a newState.

    \sa start(), stop(), pause(), resume()
*/
void QAbstractAnimation::updateState(QAbstractAnimation::State oldState,
                                     QAbstractAnimation::State newState)
{
    Q_UNUSED(oldState);
    Q_UNUSED(newState);
}

/*!
    This virtual function is called by QAbstractAnimation when the direction
    of the animation is changed. The \a direction argument is the new direction.

    \sa setDirection(), direction()
*/
void QAbstractAnimation::updateDirection(QAbstractAnimation::Direction direction)
{
    Q_UNUSED(direction);
}


QT_END_NAMESPACE

#include "moc_qabstractanimation.cpp"

#endif //QT_NO_ANIMATION