path: root/src/declarative/util/qdeclarativetransition.cpp

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#include "private/qdeclarativestate_p.h"
#include "private/qdeclarativestategroup_p.h"
#include "private/qdeclarativestate_p_p.h"
#include "private/qdeclarativestateoperations_p.h"
#include "private/qdeclarativeanimation_p.h"
#include "private/qdeclarativeanimation_p_p.h"
#include "private/qdeclarativetransitionmanager_p_p.h"

#include <QParallelAnimationGroup>

QT_BEGIN_NAMESPACE

/*!
    \qmlclass Transition QDeclarativeTransition
  \since 4.7
    \brief The Transition element defines animated transitions that occur on state changes.

    \sa {qmlstates}{States}, {state-transitions}{Transitions}, {QtDeclarative}
*/

/*!
    \internal
    \class QDeclarativeTransition
    \brief The QDeclarativeTransition class allows you to define animated transitions that occur on state changes.

    \ingroup group_states
*/

//ParallelAnimationWrapper allows us to do a "callback" when the animation finishes, rather than connecting
//and disconnecting signals and slots frequently
class ParallelAnimationWrapper : public QParallelAnimationGroup
{
    Q_OBJECT
public:
    ParallelAnimationWrapper(QObject *parent = 0) : QParallelAnimationGroup(parent) {}
    QDeclarativeTransitionPrivate *trans;
protected:
    virtual void updateState(QAbstractAnimation::State newState, QAbstractAnimation::State oldState);
};

class QDeclarativeTransitionPrivate : public QObjectPrivate
{
    Q_DECLARE_PUBLIC(QDeclarativeTransition)
public:
    QDeclarativeTransitionPrivate() 
    : fromState(QLatin1String("*")), toState(QLatin1String("*")), 
      reversed(false), reversible(false), endState(0)
    {
        group.trans = this;
    }

    QString fromState;
    QString toState;
    bool reversed;
    bool reversible;
    ParallelAnimationWrapper group;
    QDeclarativeTransitionManager *endState;

    void complete()
    {
        endState->complete();
    }
    static void append_animation(QDeclarativeListProperty<QDeclarativeAbstractAnimation> *list, QDeclarativeAbstractAnimation *a);
    QList<QDeclarativeAbstractAnimation *> animations;
};

void QDeclarativeTransitionPrivate::append_animation(QDeclarativeListProperty<QDeclarativeAbstractAnimation> *list, QDeclarativeAbstractAnimation *a)
{
    QDeclarativeTransition *q = static_cast<QDeclarativeTransition *>(list->object);
    q->d_func()->animations.append(a);
    q->d_func()->group.addAnimation(a->qtAnimation());
    a->setDisableUserControl();
}

void ParallelAnimationWrapper::updateState(QAbstractAnimation::State newState, QAbstractAnimation::State oldState)
{
    QParallelAnimationGroup::updateState(newState, oldState);
    if (newState == Stopped && (duration() == -1
        || (direction() == QAbstractAnimation::Forward && currentLoopTime() == duration())
        || (direction() == QAbstractAnimation::Backward && currentLoopTime() == 0)))
    {
        trans->complete();
    }
}



QDeclarativeTransition::QDeclarativeTransition(QObject *parent)
    : QObject(*(new QDeclarativeTransitionPrivate), parent)
{
}

QDeclarativeTransition::~QDeclarativeTransition()
{
}

void QDeclarativeTransition::stop()
{
    Q_D(QDeclarativeTransition);
    d->group.stop();
}

void QDeclarativeTransition::setReversed(bool r)
{
    Q_D(QDeclarativeTransition);
    d->reversed = r;
}

void QDeclarativeTransition::prepare(QDeclarativeStateOperation::ActionList &actions,
                            QList<QDeclarativeProperty> &after,
                            QDeclarativeTransitionManager *endState)
{
    Q_D(QDeclarativeTransition);

    qmlExecuteDeferred(this);

    if (d->reversed) {
        for (int ii = d->animations.count() - 1; ii >= 0; --ii) {
            d->animations.at(ii)->transition(actions, after, QDeclarativeAbstractAnimation::Backward);
        }
    } else {
        for (int ii = 0; ii < d->animations.count(); ++ii) {
            d->animations.at(ii)->transition(actions, after, QDeclarativeAbstractAnimation::Forward);
        }
    }

    d->endState = endState;
    d->group.setDirection(d->reversed ? QAbstractAnimation::Backward : QAbstractAnimation::Forward);
    d->group.start();
}

/*!
    \qmlproperty string Transition::from
    \qmlproperty string Transition::to
    These properties are selectors indicating which state changes should trigger the transition.

    from is used in conjunction with to to determine when a transition should
    be applied. By default from and to are both "*" (any state). In the following example,
    the transition is applied when changing from state1 to state2.
    \code
    Transition {
        from: "state1"
        to: "state2"
        ...
    }
    \endcode
*/
QString QDeclarativeTransition::fromState() const
{
    Q_D(const QDeclarativeTransition);
    return d->fromState;
}

void QDeclarativeTransition::setFromState(const QString &f)
{
    Q_D(QDeclarativeTransition);
    if (f == d->fromState)
        return;

    d->fromState = f;
    emit fromChanged();
}

/*!
    \qmlproperty bool Transition::reversible
    This property holds whether the transition should be automatically reversed when the conditions that triggered this transition are reversed.

    The default value is false.
*/
bool QDeclarativeTransition::reversible() const
{
    Q_D(const QDeclarativeTransition);
    return d->reversible;
}

void QDeclarativeTransition::setReversible(bool r)
{
    Q_D(QDeclarativeTransition);
    if (r == d->reversible)
        return;

    d->reversible = r;
    emit reversibleChanged();
}

QString QDeclarativeTransition::toState() const
{
    Q_D(const QDeclarativeTransition);
    return d->toState;
}

void QDeclarativeTransition::setToState(const QString &t)
{
    Q_D(QDeclarativeTransition);
    if (t == d->toState)
        return;

    d->toState = t;
    emit toChanged();
}

/*!
    \qmlproperty list<Animation> Transition::animations
    \default
    This property holds a list of the animations to be run for this transition.

    The top-level animations are run in parallel. To run them sequentially,
    you can create a single SequentialAnimation which contains all the animations,
    and assign that to animations the animations property.
    \default
*/
QDeclarativeListProperty<QDeclarativeAbstractAnimation> QDeclarativeTransition::animations()
{
    Q_D(QDeclarativeTransition);
    return QDeclarativeListProperty<QDeclarativeAbstractAnimation>(this, &d->animations, QDeclarativeTransitionPrivate::append_animation);
}

QT_END_NAMESPACE

#include <qdeclarativetransition.moc>