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_MEDIANODE_H

    20 #define PHONON_MMF_MEDIANODE_H

    21 

    22 #include <QObject>

    23 #include <Phonon/EffectInterface>

    24 #include "audioplayer.h"

    25 

    26 QT_BEGIN_NAMESPACE

    27 

    28 /**

    29  * @file mmf_medianode.h mmf_medianode.cpp

    30  *

    31  * This file starts with mmf_ in order to avoid clash with Phonon's

    32  * medianode.h. The GStreamer backend has a file named medianode.h, but it

    33  * isn't compiled with ABLD build system, which have problems with separating

    34  * user and system include paths.

    35  */

    36 

    37 namespace Phonon

    38 {

    39 namespace MMF

    40 {

    41 class MediaObject;

    42 

    43 /**

    44  * @short Base class for all nodes in the MMF backend.

    45  *

    46  * MediaNode is the base class for all nodes in the chain for MMF. Currently

    47  * they are:

    48  *

    49  * - MediaObject: a source of media

    50  * - AbstractEffect: supplying audio effects

    51  * - AudioOutput: pretty much a dummy interface, but is also MediaNode in order

    52  *   to simplify connection/disconnection.

    53  *

    54  * MediaNode provides spectatability into the chain, and also allows the

    55  * connection code to be written in a polymorphic manner, instead of putting it

    56  * all in the Backend class. Due to that MMF has no concept of chaining, the

    57  * order of the nodes in the graph has no meaning.

    58  */

    59 class MediaNode : public QObject

    60 {

    61     Q_OBJECT

    62 public:

    63     MediaNode(QObject *parent);

    64 

    65     virtual bool connectMediaNode(MediaNode *target);

    66     virtual bool disconnectMediaNode(MediaNode *target);

    67     void setSource(MediaNode *source);

    68 

    69     MediaNode *source() const;

    70     MediaNode *target() const;

    71 

    72 protected:

    73     /**

    74      * When connectMediaNode() is called and a MediaObject is part of

    75      * the its graph, this function will be called for each MediaNode in the

    76      * graph for which it hasn't been called yet.

    77      *

    78      * The caller guarantees that @p mo is always non-null.

    79      */

    80     virtual bool activateOnMediaObject(MediaObject *mo) = 0;

    81 

    82 private:

    83     /**

    84      * Finds a MediaObject anywhere in the graph @p target is apart of, and

    85      * calls activateOnMediaObject() for all MediaNodes in the graph for which

    86      * it hasn't been applied to already.

    87      */

    88     bool applyNodesOnMediaObject(MediaNode *target);

    89 

    90     MediaNode * m_source;

    91     MediaNode * m_target;

    92     bool        m_isApplied;

    93 };

    94 }

    95 }

    96 

    97 QT_END_NAMESPACE

    98 

    99 #endif

   100