annotate data/model/Model.h @ 1752:6d09d68165a4 by-id

Further review of ById: make IDs only available when adding a model to the ById store, not by querying the item directly. This means any id encountered in the wild must have been added to the store at some point (even if later released), which simplifies reasoning about lifecycles

/* -*- 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 SV_MODEL_H
#define SV_MODEL_H

#include <vector>
#include <QObject>

#include "base/ById.h"
#include "base/XmlExportable.h"
#include "base/Playable.h"
#include "base/BaseTypes.h"
#include "base/DataExportOptions.h"

class ZoomConstraint;
class AlignmentModel;

/** 
 * Model is the base class for all data models that represent any sort
 * of data on a time scale based on an audio frame rate.
 */
class Model : public QObject,
              public WithTypedId<Model>,
              public XmlExportable,
              public Playable
{
    Q_OBJECT

public:
    typedef Id ModelId;
    
    virtual ~Model();

    /**
     * Return true if the model was constructed successfully.  Classes
     * that refer to the model should always test this before use.
     */
    virtual bool isOK() const = 0;

    /**
     * Return the first audio frame spanned by the model.
     */
    virtual sv_frame_t getStartFrame() const = 0;

    /**
     * Return the audio frame at the end of the model, i.e. the final
     * frame contained within the model plus 1 (rounded up to the
     * model's "resolution" granularity, if more than 1). The end
     * frame minus the start frame should yield the total duration in
     * frames (as a multiple of the resolution) spanned by the
     * model. This is broadly consistent with the definition of the
     * end frame of a Selection object.
     *
     * If the end has been extended by extendEndFrame() beyond the
     * true end frame, return the extended end instead. This is
     * usually the behaviour you want.
     */
    sv_frame_t getEndFrame() const {
        sv_frame_t trueEnd = getTrueEndFrame();
        if (m_extendTo > trueEnd) {
            return m_extendTo;
        } else {
            return trueEnd;
        }
    }

    /**
     * Return the audio frame at the end of the model. This is
     * identical to getEndFrame(), except that it ignores any extended
     * duration set with extendEndFrame().
     */
    virtual sv_frame_t getTrueEndFrame() const = 0;

    /**
     * Extend the end of the model. If this is set to something beyond
     * the true end of the data within the model, then getEndFrame()
     * will return this value instead of the true end. (This is used
     * by the Tony application.)
     */
    void extendEndFrame(sv_frame_t to) {
        m_extendTo = to;
    }

    /**
     * Return the frame rate in frames per second.
     */
    virtual sv_samplerate_t getSampleRate() const = 0;

    /**
     * Return the frame rate of the underlying material, if the model
     * itself has already been resampled.
     */
    virtual sv_samplerate_t getNativeRate() const { return getSampleRate(); }

    /**
     * Return the "work title" of the model, if known.
     */
    virtual QString getTitle() const;

    /**
     * Return the "artist" or "maker" of the model, if known.
     */
    virtual QString getMaker() const;

    /**
     * Return the location of the data in this model (e.g. source
     * URL).  This should not normally be returned for editable models
     * that have been edited.
     */
    virtual QString getLocation() const;

    /**
     * Return the type of the model.  For display purposes only.
     */
    virtual QString getTypeName() const = 0;

    /**
     * Return true if this is a sparse model.
     */
    virtual bool isSparse() const { return false; }

    /**
     * Mark the model as abandoning. This means that the application
     * no longer needs it, so it can stop doing any background
     * calculations it may be involved in. Note that as far as the
     * model API is concerned, this does nothing more than tell the
     * model to return true from isAbandoning().  The actual response
     * to this will depend on the model's context -- it's possible
     * nothing at all will change.
     */
    //!!! aim to lose this (???)
    /*!!!
    virtual void abandon() {
        m_abandoning = true;
    }
    */
    
    /**
     * Query whether the model has been marked as abandoning.
     */
    //!!! aim to lose this
    /*!!!
    virtual bool isAbandoning() const { 
        return m_abandoning;
    }
    */
    /**
     * Return true if the model has finished loading or calculating
     * all its data, for a model that is capable of calculating in a
     * background thread.
     *
     * If "completion" is non-NULL, return through it an estimated
     * percentage value showing how far through the background
     * operation it thinks it is (for progress reporting). This should
     * be identical to the value returned by getCompletion().
     *
     * A model that carries out all its calculation from the
     * constructor or accessor functions would typically return true
     * (and completion == 100) as long as isOK() is true. Other models
     * may make the return value here depend on the internal
     * completion status.
     *
     * See also getCompletion().
     */
    virtual bool isReady(int *cp = nullptr) const {
        int c = getCompletion();
        if (cp) *cp = c;
        if (!isOK()) return false;
        else return (c == 100);
    }
    
    /**
     * Return an estimated percentage value showing how far through
     * any background operation used to calculate or load the model
     * data the model thinks it is. Must return 100 when the model is
     * complete.
     *
     * A model that carries out all its calculation from the
     * constructor or accessor functions might return 0 if isOK() is
     * false and 100 if isOK() is true. Other models may make the
     * return value here depend on the internal completion status.
     *
     * See also isReady().
     */
    virtual int getCompletion() const = 0;

    /**
     * If this model imposes a zoom constraint, i.e. some limit to the
     * set of resolutions at which its data can meaningfully be
     * displayed, then return it.
     */
    virtual const ZoomConstraint *getZoomConstraint() const {
        return 0;
    }

    /**
     * If this model was derived from another, return the id of the
     * model it was derived from.  The assumption is that the source
     * model's alignment will also apply to this model, unless some
     * other property (such as a specific alignment model set on this
     * model) indicates otherwise.
     */
    virtual ModelId getSourceModel() const {
        return m_sourceModel;
    }

    /**
     * Set the source model for this model.
     */
    virtual void setSourceModel(ModelId model);

    /**
     * Specify an alignment between this model's timeline and that of
     * a reference model. The alignment model, of type AlignmentModel,
     * records both the reference and the alignment. This model "takes
     * ownership" of alignmentModel, in that we take responsibility
     * for calling ModelById::release() for it from our own destructor
     * (no other class needs to know about the alignment model).

     *!!! I don't think the above is a good idea - I think document
          should record alignment models and release them
     */
    virtual void setAlignment(ModelId alignmentModel);

    /**
     * Retrieve the alignment model for this model.  This is not a
     * generally useful function, as the alignment you really want may
     * be performed by the source model instead.  You should normally
     * use getAlignmentReference, alignToReference and
     * alignFromReference instead of this.  The main intended
     * application for this function is in streaming out alignments to
     * the session file.
     */
    virtual const ModelId getAlignment() const;

    /**
     * Return the reference model for the current alignment timeline,
     * if any.
     */
    virtual const ModelId getAlignmentReference() const;

    /**
     * Return the frame number of the reference model that corresponds
     * to the given frame number in this model.
     */
    virtual sv_frame_t alignToReference(sv_frame_t frame) const;

    /**
     * Return the frame number in this model that corresponds to the
     * given frame number of the reference model.
     */
    virtual sv_frame_t alignFromReference(sv_frame_t referenceFrame) const;

    /**
     * Return the completion percentage for the alignment model: 100
     * if there is no alignment model or it has been entirely
     * calculated, or less than 100 if it is still being calculated.
     */
    virtual int getAlignmentCompletion() const;

    /**
     * Set the event, feature, or signal type URI for the features
     * contained in this model, according to the Audio Features RDF
     * ontology.
     */
    void setRDFTypeURI(QString uri) { m_typeUri = uri; }

    /**
     * Retrieve the event, feature, or signal type URI for the
     * features contained in this model, if previously set with
     * setRDFTypeURI.
     */
    QString getRDFTypeURI() const { return m_typeUri; }

    void toXml(QTextStream &stream,
               QString indent = "",
               QString extraAttributes = "") const override;

    virtual QString toDelimitedDataString(QString delimiter,
                                          DataExportOptions options,
                                          sv_frame_t startFrame,
                                          sv_frame_t duration) const = 0;

signals:
    /**
     * Emitted when a model has been edited (or more data retrieved
     * from cache, in the case of a cached model that generates slowly)
     */
    void modelChanged(ModelId myId);

    /**
     * Emitted when a model has been edited (or more data retrieved
     * from cache, in the case of a cached model that generates slowly)
     */
    void modelChangedWithin(ModelId myId, sv_frame_t startFrame, sv_frame_t endFrame);

    /**
     * Emitted when some internal processing has advanced a stage, but
     * the model has not changed externally.  Views should respond by
     * updating any progress meters or other monitoring, but not
     * refreshing the actual view.
     */
    void completionChanged(ModelId myId);

    /**
     * Emitted when internal processing is complete (i.e. when
     * isReady() would return true, with completion at 100).
     */
    void ready(ModelId myId);

    /**
     * Emitted when the completion percentage changes for the
     * calculation of this model's alignment model.
     */
    void alignmentCompletionChanged(ModelId myId);

protected:
    Model() :
//!!!        m_abandoning(false), 
        m_extendTo(0) { }

    // Not provided.
    Model(const Model &) =delete;
    Model &operator=(const Model &) =delete;

    ModelId m_sourceModel;
    ModelId m_alignmentModel;
    QString m_typeUri;
//!!!    bool m_abandoning;
    sv_frame_t m_extendTo;
};

typedef Model::Id ModelId;
typedef TypedById<Model, Model::Id> ModelById;

#endif