#include <phonon/effectinterface.h>

 * MediaNode is the base class for all nodes created by the MMF

 * backend.

 *

 * These nodes may be one of the following types:

 * - MediaObject

 *      This represents the source of media data.  It encapsulates the

 *      appropriate MMF client API for playing audio or video.

 * - AudioOutput

 *      This represents the audio output device.  Since the MMF client API

 *      does not expose the output device directly, this backend node

 *      simply forwards volume control commands to the MediaObject.

 * - VideoWidget

 *      A native widget on which video will be rendered.

 * - An audio effect, derived form AbstractAudioEffect

 * Because the MMF API does not support the concept of a media filter graph,

 * this class must ensure the following:

 *

 * - Each media graph contains at most one MediaObject instance.

 * - Every non-MediaObject node holds a reference to the MediaObject.  This

 * allows commands to be sent through the graph to the encapsulated MMF client

 * API.

    ~MediaNode();

    bool connectOutput(MediaNode *output);

    bool disconnectOutput(MediaNode *output);

    virtual void connectMediaObject(MediaObject *mediaObject) = 0;

    virtual void disconnectMediaObject(MediaObject *mediaObject) = 0;

    bool isMediaObject() const;

    void updateMediaObject();

    void setMediaObject(MediaObject *mediaObject);

    typedef QList<const MediaNode *> NodeList;

    void visit(QList<MediaNode *>& visited, MediaObject*& mediaObject);

private:

    MediaObject *       m_mediaObject;

    // All nodes except MediaObject may have an input

    MediaNode *         m_input;

    // Only MediaObject can have more than one output

    QList<MediaNode *>  m_outputs;