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#include "qmlbehavior_p.h"

#include "qmlanimation_p.h"
#include "qmltransition_p.h"

#include <qmlcontext.h>
#include <qmlinfo.h>

#include <QtCore/qparallelanimationgroup.h>

#include <private/qobject_p.h>

QT_BEGIN_NAMESPACE



class QmlBehaviorPrivate : public QObjectPrivate
{
    Q_DECLARE_PUBLIC(QmlBehavior)
public:
    QmlBehaviorPrivate() : animation(0), enabled(true) {}

    QmlMetaProperty property;
    QVariant currentValue;
    QmlAbstractAnimation *animation;
    bool enabled;
};

/*!
    \qmlclass Behavior QmlBehavior
    \brief The Behavior element allows you to specify a default animation for a property change.

    Behaviors provide one way to specify \l{qmlanimation.html}{animations} in QML.

    In the example below, the rect will use a bounce easing curve over 200 millisecond for any changes to its y property:
    \code
    Rectangle {
        width: 20; height: 20
        color: "#00ff00"
        y: 200  //initial value
        y: Behavior {
            NumberAnimation {
                easing: "easeOutBounce(amplitude:100)"
                duration: 200
            }
        }
    }
    \endcode

    Currently only a single Behavior may be specified for a property;
    this Behavior can be enabled and disabled via the \l{enabled} property.
*/


QmlBehavior::QmlBehavior(QObject *parent)
    : QObject(*(new QmlBehaviorPrivate), parent)
{
}

QmlBehavior::~QmlBehavior()
{
}

/*!
    \qmlproperty Animation Behavior::animation
    \default

    The animation to use when the behavior is triggered.
*/

QmlAbstractAnimation *QmlBehavior::animation()
{
    Q_D(QmlBehavior);
    return d->animation;
}

void QmlBehavior::setAnimation(QmlAbstractAnimation *animation)
{
    Q_D(QmlBehavior);
    if (d->animation) {
        qmlInfo(this) << tr("Cannot change the animation assigned to a Behavior.");
        return;
    }

    d->animation = animation;
    if (d->animation) {
        d->animation->setDefaultTarget(d->property);
        d->animation->setDisableUserControl();
    }
}

/*!
    \qmlproperty bool Behavior::enabled
    Whether the Behavior will be triggered when the property it is tracking changes.

    By default a Behavior is enabled.
*/

bool QmlBehavior::enabled() const
{
    Q_D(const QmlBehavior);
    return d->enabled;
}

void QmlBehavior::setEnabled(bool enabled)
{
    Q_D(QmlBehavior);
    if (d->enabled == enabled)
        return;
    d->enabled = enabled;
    emit enabledChanged();
}

void QmlBehavior::write(const QVariant &value)
{
    Q_D(QmlBehavior);
    if (!d->animation || !d->enabled) {
        d->property.write(value, QmlMetaProperty::BypassInterceptor | QmlMetaProperty::DontRemoveBinding);
        return;
    }

    d->currentValue = d->property.read();

    d->animation->qtAnimation()->stop();

    QmlStateOperation::ActionList actions;
    QmlAction action;
    action.property = d->property;
    action.fromValue = d->currentValue;
    action.toValue = value;
    actions << action;

    QList<QmlMetaProperty> after;
    if (d->animation)
        d->animation->transition(actions, after, QmlAbstractAnimation::Forward);
    d->animation->qtAnimation()->start();
    if (!after.contains(d->property))
        d->property.write(value, QmlMetaProperty::BypassInterceptor | QmlMetaProperty::DontRemoveBinding);
}

void QmlBehavior::setTarget(const QmlMetaProperty &property)
{
    Q_D(QmlBehavior);
    d->property = property;
    d->currentValue = property.read();
    if (d->animation)
        d->animation->setDefaultTarget(property);
}

QT_END_NAMESPACE