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** Copyright (C) 2014 Digia Plc and/or its subsidiary(-ies).
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** accordance with the commercial license agreement provided with the
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****************************************************************************/

#ifndef FOLLOWEMITTER_H
#define FOLLOWEMITTER_H
#include "qquickparticleemitter_p.h"
#include "qquickparticleaffector_p.h"

QT_BEGIN_NAMESPACE

class QQuickTrailEmitter : public QQuickParticleEmitter
{
    Q_OBJECT
    Q_PROPERTY(QString follow READ follow WRITE setFollow NOTIFY followChanged)
    Q_PROPERTY(int emitRatePerParticle READ particlesPerParticlePerSecond WRITE setParticlesPerParticlePerSecond NOTIFY particlesPerParticlePerSecondChanged)

    Q_PROPERTY(QQuickParticleExtruder* emitShape READ emissonShape WRITE setEmissionShape NOTIFY emissionShapeChanged)
    Q_PROPERTY(qreal emitHeight READ emitterYVariation WRITE setEmitterYVariation NOTIFY emitterYVariationChanged)
    Q_PROPERTY(qreal emitWidth READ emitterXVariation WRITE setEmitterXVariation NOTIFY emitterXVariationChanged)

    Q_ENUMS(EmitSize)
public:
    enum EmitSize {
        ParticleSize = -2//Anything less than 0 will do
    };
    explicit QQuickTrailEmitter(QQuickItem *parent = 0);
    virtual void emitWindow(int timeStamp);
    virtual void reset();

    int particlesPerParticlePerSecond() const
    {
        return m_particlesPerParticlePerSecond;
    }

    qreal emitterXVariation() const
    {
        return m_emitterXVariation;
    }

    qreal emitterYVariation() const
    {
        return m_emitterYVariation;
    }

    QString follow() const
    {
        return m_follow;
    }

    QQuickParticleExtruder* emissonShape() const
    {
        return m_emissionExtruder;
    }

Q_SIGNALS:
    void emitFollowParticles(QQmlV4Handle particles, QQmlV4Handle followed);

    void particlesPerParticlePerSecondChanged(int arg);

    void emitterXVariationChanged(qreal arg);

    void emitterYVariationChanged(qreal arg);

    void followChanged(const QString &arg);

    void emissionShapeChanged(QQuickParticleExtruder* arg);

public Q_SLOTS:

    void setParticlesPerParticlePerSecond(int arg)
    {
        if (m_particlesPerParticlePerSecond != arg) {
            m_particlesPerParticlePerSecond = arg;
            Q_EMIT particlesPerParticlePerSecondChanged(arg);
        }
    }
    void setEmitterXVariation(qreal arg)
    {
        if (m_emitterXVariation != arg) {
            m_emitterXVariation = arg;
            Q_EMIT emitterXVariationChanged(arg);
        }
    }

    void setEmitterYVariation(qreal arg)
    {
        if (m_emitterYVariation != arg) {
            m_emitterYVariation = arg;
            Q_EMIT emitterYVariationChanged(arg);
        }
    }

    void setFollow(const QString &arg)
    {
        if (m_follow != arg) {
            m_follow = arg;
            Q_EMIT followChanged(arg);
        }
    }

    void setEmissionShape(QQuickParticleExtruder* arg)
    {
        if (m_emissionExtruder != arg) {
            m_emissionExtruder = arg;
            Q_EMIT emissionShapeChanged(arg);
        }
    }

private Q_SLOTS:
    void recalcParticlesPerSecond();

private:
    QSet<QQuickParticleData*> m_pending;
    QVector<qreal> m_lastEmission;
    int m_particlesPerParticlePerSecond;
    qreal m_lastTimeStamp;
    qreal m_emitterXVariation;
    qreal m_emitterYVariation;
    QString m_follow;
    int m_followCount;
    QQuickParticleExtruder* m_emissionExtruder;
    QQuickParticleExtruder* m_defaultEmissionExtruder;
    bool isEmitFollowConnected();
};

QT_END_NAMESPACE
#endif // FOLLOWEMITTER_H
