1 /*  This file is part of the KDE project.

     2 

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

     4 

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

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

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

     8 

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

    10 but WITHOUT ANY WARRANTY; without even the implied warranty of

    11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the

    12 GNU Lesser General Public License for more details.

    13 

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

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

    16 

    17 */

    18 

    19 #ifndef PHONON_MMF_ABSTRACTEFFECT_H

    20 #define PHONON_MMF_ABSTRACTEFFECT_H

    21 

    22 #include "mmf_medianode.h"

    23 

    24 #include <QScopedPointer>

    25 

    26 #include <AudioEffectBase.h>

    27 

    28 #include <Phonon/EffectInterface>

    29 #include <Phonon/EffectParameter>

    30 #include "audioplayer.h"

    31 

    32 QT_BEGIN_NAMESPACE

    33 

    34 namespace Phonon

    35 {

    36 namespace MMF

    37 {

    38 

    39 /**

    40  * @short Base class for all effects for MMF.

    41  *

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

    43  *

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

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

    46  *   undefined.

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

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

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

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

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

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

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

    54  */

    55 class AbstractAudioEffect : public MediaNode

    56                           , public EffectInterface

    57 {

    58     Q_OBJECT

    59     Q_INTERFACES(Phonon::EffectInterface)

    60 public:

    61     AbstractAudioEffect(QObject *parent,

    62                         const QList<EffectParameter> &params);

    63 

    64     virtual QList<EffectParameter> parameters() const;

    65     virtual QVariant parameterValue(const EffectParameter &param) const;

    66     virtual void setParameterValue(const EffectParameter &,

    67                                    const QVariant &newValue);

    68 

    69     virtual bool disconnectMediaNode(MediaNode *target);

    70 

    71     enum Type

    72     {

    73         EffectAudioEqualizer = 1,

    74         EffectBassBoost,

    75         EffectDistanceAttenuation,

    76         EffectEnvironmentalReverb,

    77         EffectListenerOrientation,

    78         EffectLoudness,

    79         EffectSourceOrientation,

    80         EffectStereoWidening

    81     };

    82 

    83 protected:

    84     virtual bool activateOn(CPlayerType *player) = 0;

    85     virtual void parameterChanged(const int id,

    86                                   const QVariant &value) = 0;

    87 

    88     /**

    89      * Part of the implementation of AbstractAudioEffect. Forwards the call to

    90      * activateOn(), essentially.

    91      */

    92     virtual bool activateOnMediaObject(MediaObject *mo);

    93 

    94     QScopedPointer<CAudioEffect>    m_effect;

    95 private:

    96     const QList<EffectParameter>    m_params;

    97     QHash<int, QVariant>            m_values;

    98 };

    99 }

   100 }

   101 

   102 QT_END_NAMESPACE

   103 

   104 #endif

   105