view transform/ModelTransformer.h @ 718:f3fd2988fc9b

Fix incorrect query structure for output type URIs. This led to some output RDF features being written with type URIs intended for different outputs. Also revert some SVDEBUGs to cerrs -- they are intended as user-visible errors or warnings rather than debug

/* -*- c-basic-offset: 4 indent-tabs-mode: nil -*-  vi:set ts=8 sts=4 sw=4: */

/*
    Sonic Visualiser
    An audio file viewer and annotation editor.
    Centre for Digital Music, Queen Mary, University of London.
    This file copyright 2006 Chris Cannam.
   
    This program is free software; you can redistribute it and/or
    modify it under the terms of the GNU General Public License as
    published by the Free Software Foundation; either version 2 of the
    License, or (at your option) any later version.  See the file
    COPYING included with this distribution for more information.
*/

#ifndef _TRANSFORMER_H_
#define _TRANSFORMER_H_

#include "base/Thread.h"

#include "data/model/Model.h"

#include "Transform.h"

/**
 * A ModelTransformer turns one data model into another.
 *
 * Typically in this application, a ModelTransformer might have a
 * DenseTimeValueModel as its input (e.g. an audio waveform) and a
 * SparseOneDimensionalModel (e.g. detected beats) as its output.
 *
 * The ModelTransformer typically runs in the background, as a
 * separate thread populating the output model.  The model is
 * available to the user of the ModelTransformer immediately, but may
 * be initially empty until the background thread has populated it.
 */

class ModelTransformer : public Thread
{
public:
    virtual ~ModelTransformer();

    class Input {
    public:
        Input(Model *m) : m_model(m), m_channel(-1) { }
        Input(Model *m, int c) : m_model(m), m_channel(c) { }

        Model *getModel() const { return m_model; }
        void setModel(Model *m) { m_model = m; }

        int getChannel() const { return m_channel; }
        void setChannel(int c) { m_channel = c; }

    protected:
        Model *m_model;
        int m_channel;
    };

    /**
     * Hint to the processing thread that it should give up, for
     * example because the process is going to exit or we want to get
     * rid of the input model.  Caller should still wait() and/or
     * delete the transform before assuming its input and output
     * models are no longer required.
     */
    void abandon() { m_abandoned = true; }

    /**
     * Return the input model for the transform.
     */
    Model *getInputModel()  { return m_input.getModel(); }

    /**
     * Return the input channel spec for the transform.
     */
    int getInputChannel() { return m_input.getChannel(); }

    /**
     * Return the output model created by the transform.  Returns a
     * null model if the transform could not be initialised; an error
     * message may be available via getMessage() in this situation.
     */
    Model *getOutputModel() { return m_output; }

    /**
     * Return the output model, also detaching it from the transformer
     * so that it will not be deleted when the transformer is.  The
     * caller takes ownership of the model.
     */
    Model *detachOutputModel() { m_detached = true; return m_output; }

    /**
     * Return a warning or error message.  If getOutputModel returned
     * a null pointer, this should contain a fatal error message for
     * the transformer; otherwise it may contain a warning to show to
     * the user about e.g. suboptimal block size or whatever.  
     */
    QString getMessage() const { return m_message; }

protected:
    ModelTransformer(Input input, const Transform &transform);

    Transform m_transform;
    Input m_input; // I don't own the model in this
    Model *m_output; // I own this, unless...
    bool m_detached; // ... this is true.
    bool m_abandoned;
    QString m_message;
};

#endif