/*  This file is part of the KDE project.

Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies).

This library is free software: you can redistribute it and/or modify

it under the terms of the GNU Lesser General Public License as published by

the Free Software Foundation, either version 2.1 or 3 of the License.

This library is distributed in the hope that it will be useful,

but WITHOUT ANY WARRANTY; without even the implied warranty of

MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

GNU Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public License

along with this library.  If not, see <http://www.gnu.org/licenses/>.

*/

#ifndef PHONON_MMF_ABSTRACTEFFECT_H

#define PHONON_MMF_ABSTRACTEFFECT_H

#include <QScopedPointer>

#include <AudioEffectBase.h>

#include <phonon/effectinterface.h>

#include "audioplayer.h"

#include "effectparameter.h"

#include "mmf_medianode.h"

class CMdaAudioOutputStream;

QT_BEGIN_NAMESPACE

namespace Phonon

{

namespace MMF

{

class AbstractPlayer;

class AbstractMediaPlayer;

/**

 * @short Base class for all effects for MMF.

 *

 * Adhering to Phonon with MMF is cumbersome because of a number of reasons:

 *

 * - MMF has no concept of effect chaining. Simply, an effect is a applied

 *   to PlayerUtility, that's it. This means that the order of effects is

 *   undefined.

 * - We apply an effect to a PlayerUtility, and MediaObject has that one.

 *   However, effects might be created before MediaObject, but nevertheless

 *   needs to work. We solve this by that we are aware of the whole connection

 *   chain, and whenever a connection happens, we walk the chain, find effects

 *   that aren't applied, and apply it if we have a media object.

 * - There are plenty of corner cases which we don't handle and where behavior

 *   are undefined. For instance, graphs with more than one MediaObject.

 */

class AbstractAudioEffect : public MediaNode

                          , public EffectInterface

{

    Q_OBJECT

    Q_INTERFACES(Phonon::EffectInterface)

public:

    AbstractAudioEffect(QObject *parent,

                        const QList<EffectParameter> &params);

    // Phonon::EffectInterface

    virtual QList<Phonon::EffectParameter> parameters() const;

    virtual QVariant parameterValue(const Phonon::EffectParameter &param) const;

    virtual void setParameterValue(const Phonon::EffectParameter &,

                                   const QVariant &newValue);

    // Parameters which are shared by all effects

    enum CommonParameters

    {

        ParameterEnable = 0,

        ParameterBase // must be last entry in enum

    };

public Q_SLOTS:

    void abstractPlayerChanged(AbstractPlayer *player);

    void stateChanged(Phonon::State newState,

                      Phonon::State oldState);

protected:

    // MediaNode

    void connectMediaObject(MediaObject *mediaObject);

    void disconnectMediaObject(MediaObject *mediaObject);

    virtual void createEffect(AudioPlayer::NativePlayer *player) = 0;

    // Effect-specific parameter changed

    virtual int effectParameterChanged(const EffectParameter &param,

                                  const QVariant &value);

private:

    void createEffect();

    void setEnabled(bool enabled);

    const EffectParameter& internalParameter(int id) const;

    int parameterChanged(const EffectParameter &param,

            const QVariant &value);

protected:

    QScopedPointer<CAudioEffect>    m_effect;

private:

    const QList<EffectParameter>    m_params;

    AbstractMediaPlayer *           m_player;

    QHash<int, QVariant>            m_values;

};

}

}

// Macro for defining functions which depend on the native class name

// for each of the effects.  Using this reduces repetition of boilerplate

// in the implementations of the backend effect nodes.

#define PHONON_MMF_DEFINE_EFFECT_FUNCTIONS(Effect)                      \

                                                                        \

void Effect##::createEffect(AudioPlayer::NativePlayer *player)          \

{                                                                       \

    C##Effect *ptr = 0;                                                 \

    QT_TRAP_THROWING(ptr = C##Effect::NewL(*player));                   \

    m_effect.reset(ptr);                                                \

}                                                                       \

                                                                        \

C##Effect* Effect::concreteEffect()                                     \

{                                                                       \

    return static_cast<C##Effect *>(m_effect.data());                   \

}

QT_END_NAMESPACE

#endif