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/*!

    \class QAbstractAnimation

    \ingroup animation

    \brief The QAbstractAnimation class is the base of all animations.

    \since 4.6

    The class defines the functions for the functionality shared by

    all animations. By inheriting this class, you can create custom

    animations that plug into the rest of the animation framework.

    The progress of an animation is given by its current time

    (currentLoopTime()), which is measured in milliseconds from the start

    of the animation (0) to its end (duration()). The value is updated

    automatically while the animation is running. It can also be set

    directly with setCurrentTime().

    At any point an animation is in one of three states:

    \l{QAbstractAnimation::}{Running},

    \l{QAbstractAnimation::}{Stopped}, or

    \l{QAbstractAnimation::}{Paused}--as defined by the

    \l{QAbstractAnimation::}{State} enum. The current state can be

    changed by calling start(), stop(), pause(), or resume(). An

    animation will always reset its \l{currentTime()}{current time}

    when it is started. If paused, it will continue with the same

    current time when resumed. When an animation is stopped, it cannot

    be resumed, but will keep its current time (until started again).

    QAbstractAnimation will emit stateChanged() whenever its state

    changes.

    An animation can loop any number of times by setting the loopCount

    property. When an animation's current time reaches its duration(),

    it will reset the current time and keep running. A loop count of 1

    (the default value) means that the animation will run one time.

    Note that a duration of -1 means that the animation will run until

    stopped; the current time will increase indefinitely. When the

    current time equals duration() and the animation is in its

    final loop, the \l{QAbstractAnimation::}{Stopped} state is

    entered, and the finished() signal is emitted.

    QAbstractAnimation provides pure virtual functions used by

    subclasses to track the progress of the animation: duration() and

    updateCurrentTime(). The duration() function lets you report a

    duration for the animation (as discussed above). The animation

    framework calls updateCurrentTime() when current time has changed.

    By reimplementing this function, you can track the animation

    progress. Note that neither the interval between calls nor the

    number of calls to this function are defined; though, it will

    normally be 60 updates per second.

    By reimplementing updateState(), you can track the animation's

    state changes, which is particularly useful for animations that

    are not driven by time.

    \sa QVariantAnimation, QPropertyAnimation, 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 newState, QAbstractAnimation::State oldState)

    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

*/

#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>

#ifndef QT_NO_ANIMATION

#define DEFAULT_TIMER_INTERVAL 16

#define STARTSTOP_TIMER_DELAY 0

QT_BEGIN_NAMESPACE

Q_GLOBAL_STATIC(QThreadStorage<QUnifiedTimer *>, unifiedTimer)

QUnifiedTimer::QUnifiedTimer() :

    QObject(), lastTick(0), timingInterval(DEFAULT_TIMER_INTERVAL),

    currentAnimationIdx(0), consistentTiming(false), slowMode(false),

    isPauseTimerActive(false), runningLeafAnimations(0)

{

}

QUnifiedTimer *QUnifiedTimer::instance()

{

    QUnifiedTimer *inst;

    if (!unifiedTimer()->hasLocalData()) {

        inst = new QUnifiedTimer;

        unifiedTimer()->setLocalData(inst);

    } else {

        inst = unifiedTimer()->localData();

    }

    return inst;

}

void QUnifiedTimer::ensureTimerUpdate()

{

    if (isPauseTimerActive)

        updateAnimationsTime();

}

void QUnifiedTimer::updateAnimationsTime()

{

    // ignore consistentTiming in case the pause timer is active

    int delta = (consistentTiming && !isPauseTimerActive) ?

                        timingInterval : time.elapsed() - lastTick;

    if (slowMode)

        delta /= 5;

    lastTick = time.elapsed();

    //we make sure we only call update time if the time has actually changed

    //it might happen in some cases that the time doesn't change because events are delayed

    //when the CPU load is high

    if (delta) {

        for (currentAnimationIdx = 0; currentAnimationIdx < animations.count(); ++currentAnimationIdx) {

            QAbstractAnimation *animation = animations.at(currentAnimationIdx);

            int elapsed = QAbstractAnimationPrivate::get(animation)->totalCurrentTime

                          + (animation->direction() == QAbstractAnimation::Forward ? delta : -delta);

            animation->setCurrentTime(elapsed);

        }

        currentAnimationIdx = 0;

    }

}

void QUnifiedTimer::restartAnimationTimer()

{

    if (runningLeafAnimations == 0 && !runningPauseAnimations.isEmpty()) {

        int closestTimeToFinish = closestPauseAnimationTimeToFinish();

        if (closestTimeToFinish < 0) {

            qDebug() << runningPauseAnimations;

            qDebug() << closestPauseAnimationTimeToFinish();

        }

        animationTimer.start(closestTimeToFinish, this);

        isPauseTimerActive = true;

    } else if (!animationTimer.isActive() || isPauseTimerActive) {

        animationTimer.start(timingInterval, this);

        isPauseTimerActive = false;

    }

}

void QUnifiedTimer::timerEvent(QTimerEvent *event)

{

    //in the case of consistent timing we make sure the orders in which events come is always the same

   //for that purpose we do as if the startstoptimer would always fire before the animation timer

    if ((consistentTiming && startStopAnimationTimer.isActive()) ||

        event->timerId() == startStopAnimationTimer.timerId()) {

        startStopAnimationTimer.stop();

        //we transfer the waiting animations into the "really running" state

        animations += animationsToStart;

        animationsToStart.clear();

        if (animations.isEmpty()) {

            animationTimer.stop();

            isPauseTimerActive = false;

            // invalidate the start reference time

            time = QTime();

        } else {

            restartAnimationTimer();

            if (!time.isValid()) {

                lastTick = 0;

                time.start();

            }

        }

    }

    if (event->timerId() == animationTimer.timerId()) {

        // update current time on all top level animations

        updateAnimationsTime();

        restartAnimationTimer();

    }

}

void QUnifiedTimer::registerAnimation(QAbstractAnimation *animation, bool isTopLevel)

{

    registerRunningAnimation(animation);

    if (isTopLevel) {

        Q_ASSERT(!QAbstractAnimationPrivate::get(animation)->hasRegisteredTimer);

        QAbstractAnimationPrivate::get(animation)->hasRegisteredTimer = true;

        animationsToStart << animation;

        if (!startStopAnimationTimer.isActive())

            startStopAnimationTimer.start(STARTSTOP_TIMER_DELAY, this);

    }

}

void QUnifiedTimer::unregisterAnimation(QAbstractAnimation *animation)

{

    unregisterRunningAnimation(animation);

    if (!QAbstractAnimationPrivate::get(animation)->hasRegisteredTimer)

        return;

    int idx = animations.indexOf(animation);

    if (idx != -1) {

        animations.removeAt(idx);

        // this is needed if we unregister an animation while its running

        if (idx <= currentAnimationIdx)

            --currentAnimationIdx;

        if (animations.isEmpty() && !startStopAnimationTimer.isActive())

            startStopAnimationTimer.start(STARTSTOP_TIMER_DELAY, this);

    } else {

        animationsToStart.removeOne(animation);

    }

    QAbstractAnimationPrivate::get(animation)->hasRegisteredTimer = false;

}

void QUnifiedTimer::registerRunningAnimation(QAbstractAnimation *animation)

{

    if (QAbstractAnimationPrivate::get(animation)->isGroup)

        return;

    if (QAbstractAnimationPrivate::get(animation)->isPause) {

        runningPauseAnimations << animation;

    } else

        runningLeafAnimations++;

}

void QUnifiedTimer::unregisterRunningAnimation(QAbstractAnimation *animation)

{

    if (QAbstractAnimationPrivate::get(animation)->isGroup)

        return;

    if (QAbstractAnimationPrivate::get(animation)->isPause)

        runningPauseAnimations.removeOne(animation);

    else

        runningLeafAnimations--;

    Q_ASSERT(runningLeafAnimations >= 0);

}

int QUnifiedTimer::closestPauseAnimationTimeToFinish()

{

    int closestTimeToFinish = INT_MAX;

    for (int i = 0; i < runningPauseAnimations.size(); ++i) {

        QAbstractAnimation *animation = runningPauseAnimations.at(i);

        int timeToFinish;

        if (animation->direction() == QAbstractAnimation::Forward)

            timeToFinish = animation->duration() - animation->currentLoopTime();

        else

            timeToFinish = animation->currentLoopTime();

        if (timeToFinish < closestTimeToFinish)

            closestTimeToFinish = timeToFinish;

    }

    return closestTimeToFinish;

}

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;

    // check if we should Rewind

    if ((newState == QAbstractAnimation::Paused || newState == QAbstractAnimation::Running)

        && oldState == QAbstractAnimation::Stopped) {

            //here we reset the time if needed

            //we don't call setCurrentTime because this might change the way the animation

            //behaves: changing the state or changing the current value

            totalCurrentTime = currentTime = (direction == QAbstractAnimation::Forward) ?

                0 : (loopCount == -1 ? q->duration() : q->totalDuration());

    }

    state = newState;

    QWeakPointer<QAbstractAnimation> guard(q);

    //(un)registration of the animation must always happen before calls to

    //virtual function (updateState) to ensure a correct state of the timer

    bool isTopLevel = !group || group->state() == QAbstractAnimation::Stopped;

    if (oldState == QAbstractAnimation::Running) {

        if (newState == QAbstractAnimation::Paused && hasRegisteredTimer)

            QUnifiedTimer::instance()->ensureTimerUpdate();

        //the animation, is not running any more

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

    } else if (newState == QAbstractAnimation::Running) {

        QUnifiedTimer::instance()->registerAnimation(q, isTopLevel);

    }

    q->updateState(newState, oldState);

    if (!guard || newState != state) //this is to be safe if updateState changes the state

        return;

    // Notify state change

    emit q->stateChanged(newState, oldState);

    if (!guard || newState != state) //this is to be safe if updateState changes the state

        return;

    switch (state) {

    case QAbstractAnimation::Paused:

        break;

    case QAbstractAnimation::Running:

        {

            // this ensures that the value is updated now that the animation is running

            if (oldState == QAbstractAnimation::Stopped) {

                if (isTopLevel) {

                    // currentTime needs to be updated if pauseTimer is active

                    QUnifiedTimer::instance()->ensureTimerUpdate();

                    q->setCurrentTime(totalCurrentTime);

                }

            }

        }

        break;

    case QAbstractAnimation::Stopped:

        // Leave running state.

        int dura = q->duration();

        if (deleteWhenStopped)

            q->deleteLater();

        if (dura == -1 || loopCount < 0

            || (oldDirection == QAbstractAnimation::Forward && (oldCurrentTime * (oldCurrentLoop + 1)) == (dura * loopCount))

            || (oldDirection == QAbstractAnimation::Backward && oldCurrentTime == 0)) {

                emit q->finished();

        }

        break;

    }

}

/*!

    Constructs the QAbstractAnimation base class, and passes \a parent to

    QObject's constructor.

    \sa QVariantAnimation, QAnimationGroup

*/

QAbstractAnimation::QAbstractAnimation(QObject *parent)

    : QObject(*new QAbstractAnimationPrivate, 0)

{

    // Allow auto-add on reparent

    setParent(parent);

}

/*!

    \internal

*/

QAbstractAnimation::QAbstractAnimation(QAbstractAnimationPrivate &dd, QObject *parent)

    : QObject(dd, 0)

{

    // Allow auto-add on reparent

   setParent(parent);

}

/*!

    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);

        if (oldState == QAbstractAnimation::Running)

            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.