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

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/*!
    \class QPropertyAnimation
    \brief The QPropertyAnimation class animates properties for QObject(and QWidget)
    \ingroup animation
    \preliminary

    This class is part of {The Animation Framework}.  You can use QPropertyAnimation
    by itself as a simple animation class, or as part of more complex
    animations through QAnimationGroup.

    The most common way to use QPropertyAnimation is to construct an instance
    of it by passing a pointer to a QObject or a QWidget, and the name of the
    property you would like to animate to QPropertyAnimation's constructor.

    The start value of the animation is optional. If you do not set any start
    value, the animation will operate on the target's current property value
    at the point when the animation was started. You can call setStartValue()
    to set the start value, and setEndValue() to set the target value for
    the animated property.

    Animations can operate on QObjects and QWidgets. You can choose to assign a
    target object by either calling setTargetObject() or by passing a QObject
    pointer to QPropertyAnimation's constructor.

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

#ifndef QT_NO_ANIMATION

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

#include "qpropertyanimation_p.h"

#include <QtCore/qmath.h>
#include <QtCore/qmutex.h>

QT_BEGIN_NAMESPACE

typedef QPair<QObject *, QByteArray> QPropertyAnimationPair;
typedef QHash<QPropertyAnimationPair, QPropertyAnimation*> QPropertyAnimationHash;
Q_GLOBAL_STATIC(QPropertyAnimationHash, _q_runningAnimations);
Q_GLOBAL_STATIC_WITH_ARGS(QMutex, guardHashLock, (QMutex::Recursive) )

void QPropertyAnimationPrivate::updateMetaProperty()
{
    if (!target || propertyName.isEmpty())
        return;

    if (hasMetaProperty == 0 && !property.isValid()) {
        const QMetaObject *mo = target->metaObject();
        propertyIndex = mo->indexOfProperty(propertyName);
        if (propertyIndex != -1) {
            hasMetaProperty = 1;
            property = mo->property(propertyIndex);
            propertyType = property.userType();
        } else {
            if (!target->dynamicPropertyNames().contains(propertyName))
                qWarning("QPropertyAnimation: you're trying to animate a non-existing property %s of your QObject", propertyName.constData());
            hasMetaProperty = 2;
        }
    }

    if (property.isValid())
        convertValues(propertyType);
}

void QPropertyAnimationPrivate::updateProperty(const QVariant &newValue)
{
    if (!target || state == QAbstractAnimation::Stopped)
        return;

    if (hasMetaProperty == 1) {
        if (newValue.userType() == propertyType) {
          //no conversion is needed, we directly call the QObject::qt_metacall
          void *data = const_cast<void*>(newValue.constData());
          target->qt_metacall(QMetaObject::WriteProperty, propertyIndex, &data);
        } else {
          property.write(target, newValue);
        }
    } else {
        target->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
{
    Q_D(const QPropertyAnimation);
    return d->target;
}
void QPropertyAnimation::setTargetObject(QObject *target)
{
    Q_D(QPropertyAnimation);
    if (d->target == target)
        return;

    d->target = target;
    d->hasMetaProperty = 0;
    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);
    d->propertyName = propertyName;
    d->hasMetaProperty = 0;
    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 oldState,
                                     QAbstractAnimation::State newState)
{
    Q_D(QPropertyAnimation);

    if (!d->target) {
        qWarning("QPropertyAnimation::updateState: Changing state of an animation without target");
        return;
    }

    QVariantAnimation::updateState(oldState, newState);
    QMutexLocker locker(guardHashLock());
    QPropertyAnimationHash * hash = _q_runningAnimations();
    QPropertyAnimationPair key(d->target, d->propertyName);
    if (newState == Running) {
        d->updateMetaProperty();
        QPropertyAnimation *oldAnim = hash->value(key, 0);
        if (oldAnim) {
            // try to stop the top level group
            QAbstractAnimation *current = oldAnim;
            while (current->group() && current->state() != Stopped)
                current = current->group();
            current->stop();
        }
        hash->insert(key, this);

        // update the default start value
        if (oldState == Stopped) {
            d->setDefaultStartValue(d->target->property(d->propertyName.constData()));
        }
    } else if (hash->value(key) == this) {
        hash->remove(key);
    }
}

#include "moc_qpropertyanimation.cpp"

QT_END_NAMESPACE

#endif //QT_NO_ANIMATION