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/*!

    \class QPropertyAnimation

    \brief The QPropertyAnimation class animates Qt properties

    \since 4.6

    \ingroup animation

    QPropertyAnimation interpolates over \l{Qt's Property System}{Qt

    properties}. As property values are stored in \l{QVariant}s, the

    class inherits QVariantAnimation, and supports animation of the

    same \l{QVariant::Type}{variant types} as its super class.

    A class declaring properties must be a QObject. To make it

    possible to animate a property, it must provide a setter (so that

    QPropertyAnimation can set the property's value). Note that this

    makes it possible to animate many of Qt's widgets. Let's look at

    an example:

    \code

        QPropertyAnimation *animation = new QPropertyAnimation(myWidget, "geometry");

        animation->setDuration(10000);

        animation->setStartValue(QRect(0, 0, 100, 30));

        animation->setEndValue(QRect(250, 250, 100, 30));

        animation->start();

    \endcode

    The property name and the QObject instance of which property

    should be animated are passed to the constructor. You can then

    specify the start and end value of the property. The procedure is

    equal for properties in classes you have implemented

    yourself--just check with QVariantAnimation that your QVariant

    type is supported.

    The QVariantAnimation class description explains how to set up the

    animation in detail. Note, however, that if a start value is not

    set, the property will start at the value it had when the

    QPropertyAnimation instance was created.

    QPropertyAnimation works like a charm on its own. For complex

    animations that, for instance, contain several objects,

    QAnimationGroup is provided. An animation group is an animation

    that can contain other animations, and that can manage when its

    animations are played. Look at QParallelAnimationGroup for an

    example.

    \sa QVariantAnimation, QAnimationGroup, {The Animation Framework}

*/

#include "qpropertyanimation.h"

#include "qanimationgroup.h"

#include "qpropertyanimation_p.h"

#include <private/qmutexpool_p.h>

#ifndef QT_NO_ANIMATION

QT_BEGIN_NAMESPACE

void QPropertyAnimationPrivate::updateMetaProperty()

{

    if (!target || propertyName.isEmpty()) {

        propertyType = QVariant::Invalid;

        propertyIndex = -1;

        return;

    }

    //propertyType will be set to a valid type only if there is a Q_PROPERTY

    //otherwise it will be set to QVariant::Invalid at the end of this function

    propertyType = targetValue->property(propertyName).userType();

    propertyIndex = targetValue->metaObject()->indexOfProperty(propertyName);

    if (propertyType != QVariant::Invalid)

        convertValues(propertyType);

    if (propertyIndex == -1) {

        //there is no Q_PROPERTY on the object

        propertyType = QVariant::Invalid;

        if (!targetValue->dynamicPropertyNames().contains(propertyName))

            qWarning("QPropertyAnimation: you're trying to animate a non-existing property %s of your QObject", propertyName.constData());

    }

}

void QPropertyAnimationPrivate::updateProperty(const QVariant &newValue)

{

    if (state == QAbstractAnimation::Stopped)

        return;

    if (!target) {

        q_func()->stop(); //the target was destroyed we need to stop the animation

        return;

    }

    if (newValue.userType() == propertyType) {

        //no conversion is needed, we directly call the QMetaObject::metacall

        void *data = const_cast<void*>(newValue.constData());

        QMetaObject::metacall(targetValue, QMetaObject::WriteProperty, propertyIndex, &data);

    } else {

        targetValue->setProperty(propertyName.constData(), newValue);

    }

}

/*!

    Construct a QPropertyAnimation object. \a parent is passed to QObject's

    constructor.

*/

QPropertyAnimation::QPropertyAnimation(QObject *parent)

    : QVariantAnimation(*new QPropertyAnimationPrivate, parent)

{

}

/*!

    Construct a QPropertyAnimation object. \a parent is passed to QObject's

    constructor. The animation changes the property \a propertyName on \a

    target. The default duration is 250ms.

    \sa targetObject, propertyName

*/

QPropertyAnimation::QPropertyAnimation(QObject *target, const QByteArray &propertyName, QObject *parent)

    : QVariantAnimation(*new QPropertyAnimationPrivate, parent)

{

    setTargetObject(target);

    setPropertyName(propertyName);

}

/*!

    Destroys the QPropertyAnimation instance.

 */

QPropertyAnimation::~QPropertyAnimation()

{

    stop();

}

/*!

    \property QPropertyAnimation::targetObject

    \brief the target QObject for this animation.

    This property defines the target QObject for this animation.

 */

QObject *QPropertyAnimation::targetObject() const

{

    return d_func()->target.data();

}

void QPropertyAnimation::setTargetObject(QObject *target)

{

    Q_D(QPropertyAnimation);

    if (d->targetValue == target)

        return;

    if (d->state != QAbstractAnimation::Stopped) {

        qWarning("QPropertyAnimation::setTargetObject: you can't change the target of a running animation");

        return;

    }

    d->target = d->targetValue = target;

    d->updateMetaProperty();

}

/*!

    \property QPropertyAnimation::propertyName

    \brief the target property name for this animation

    This property defines the target property name for this animation. The

    property name is required for the animation to operate.

 */

QByteArray QPropertyAnimation::propertyName() const

{

    Q_D(const QPropertyAnimation);

    return d->propertyName;

}

void QPropertyAnimation::setPropertyName(const QByteArray &propertyName)

{

    Q_D(QPropertyAnimation);

    if (d->state != QAbstractAnimation::Stopped) {

        qWarning("QPropertyAnimation::setPropertyName: you can't change the property name of a running animation");

        return;

    }

    d->propertyName = propertyName;

    d->updateMetaProperty();

}

/*!

    \reimp

 */

bool QPropertyAnimation::event(QEvent *event)

{

    return QVariantAnimation::event(event);

}

/*!

    This virtual function is called by QVariantAnimation whenever the current value

    changes. \a value is the new, updated value. It updates the current value

    of the property on the target object.

    \sa currentValue, currentTime

 */

void QPropertyAnimation::updateCurrentValue(const QVariant &value)

{

    Q_D(QPropertyAnimation);

    d->updateProperty(value);

}

/*!

    \reimp

    If the startValue is not defined when the state of the animation changes from Stopped to Running,

    the current property value is used as the initial value for the animation.

*/

void QPropertyAnimation::updateState(QAbstractAnimation::State newState,

                                     QAbstractAnimation::State oldState)

{

    Q_D(QPropertyAnimation);

    if (!d->target && oldState == Stopped) {

        qWarning("QPropertyAnimation::updateState (%s): Changing state of an animation without target",

                 d->propertyName.constData());

        return;

    }

    QVariantAnimation::updateState(newState, oldState);

    QPropertyAnimation *animToStop = 0;

    {

        QMutexLocker locker(QMutexPool::globalInstanceGet(&staticMetaObject));

        typedef QPair<QObject *, QByteArray> QPropertyAnimationPair;

        typedef QHash<QPropertyAnimationPair, QPropertyAnimation*> QPropertyAnimationHash;

        static QPropertyAnimationHash hash;

        //here we need to use value because we need to know to which pointer

        //the animation was referring in case stopped because the target was destroyed

        QPropertyAnimationPair key(d->targetValue, d->propertyName);

        if (newState == Running) {

            d->updateMetaProperty();

            animToStop = hash.value(key, 0);

            hash.insert(key, this);

            // update the default start value

            if (oldState == Stopped) {

                d->setDefaultStartEndValue(d->targetValue->property(d->propertyName.constData()));

                //let's check if we have a start value and an end value

                if (!startValue().isValid() && (d->direction == Backward || !d->defaultStartEndValue.isValid())) {

                    qWarning("QPropertyAnimation::updateState (%s, %s, %s): starting an animation without start value",

                             d->propertyName.constData(), d->target.data()->metaObject()->className(),

                             qPrintable(d->target.data()->objectName()));

                }

                if (!endValue().isValid() && (d->direction == Forward || !d->defaultStartEndValue.isValid())) {

                    qWarning("QPropertyAnimation::updateState (%s, %s, %s): starting an animation without end value",

                             d->propertyName.constData(), d->target.data()->metaObject()->className(),

                             qPrintable(d->target.data()->objectName()));

                }

            }

        } else if (hash.value(key) == this) {

            hash.remove(key);

        }

    }

    //we need to do that after the mutex was unlocked

    if (animToStop) {

        // try to stop the top level group

        QAbstractAnimation *current = animToStop;

        while (current->group() && current->state() != Stopped)

            current = current->group();

        current->stop();

    }

}

#include "moc_qpropertyanimation.cpp"

QT_END_NAMESPACE

#endif //QT_NO_ANIMATION