annotate data/model/Model.h @ 1455:ec9e65fcf749

The use of the begin/end pairs here just seems to cause too many rows to be deleted (from the visual representation, not the underlying model). Things apparently work better if we just modify the underlying model and let the change signals percolate back up again. To that end, update the change handlers so as to cover their proper ranges with dataChanged signals.

/* -*- 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 _MODEL_H_
#define _MODEL_H_

#include <vector>
#include <QObject>

#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 XmlExportable,
              public Playable
{
    Q_OBJECT

public:
    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. 1 more
     * than the final frame contained within the model. The end frame
     * minus the start frame should yield the total duration in frames
     * spanned by the model. This is consistent with the definition of
     * the end frame of a Selection object.
     */
    virtual sv_frame_t getEndFrame() const = 0;

    /**
     * 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.
     */
    virtual void abandon() {
        m_abandoning = true;
    }

    /**
     * Query whether the model has been marked as abandoning.
     */
    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.  The default implementation is appropriate
     * for a thread that does not background any work but carries out
     * all its calculation from the constructor or accessors.
     *
     * If "completion" is non-NULL, this function should return
     * through it an estimated percentage value showing how far
     * through the background operation it thinks it is (for progress
     * reporting).  If it has no way to calculate progress, it may
     * return the special value COMPLETION_UNKNOWN.  See also
     * getCompletion().
     */
    virtual bool isReady(int *completion = 0) const {
        bool ok = isOK();
        if (completion) *completion = (ok ? 100 : 0);
        return ok;
    }
    static const int COMPLETION_UNKNOWN;

    /**
     * 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 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 Model *getSourceModel() const {
        return m_sourceModel;
    }

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

    /**
     * Specify an aligment between this model's timeline and that of a
     * reference model.  The alignment model records both the
     * reference and the alignment.  This model takes ownership of the
     * alignment model.
     */
    virtual void setAlignment(AlignmentModel *alignment);

    /**
     * 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 AlignmentModel *getAlignment() const;

    /**
     * Return the reference model for the current alignment timeline,
     * if any.
     */
    virtual const Model *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; }

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

    virtual QString toDelimitedDataString(QString delimiter) const {
        return toDelimitedDataStringSubset
            (delimiter, getStartFrame(), getEndFrame());
    }
    virtual QString toDelimitedDataStringWithOptions(QString delimiter, DataExportOptions opts) const {
        return toDelimitedDataStringSubsetWithOptions
            (delimiter, opts, getStartFrame(), getEndFrame());
    }
    virtual QString toDelimitedDataStringSubset(QString, sv_frame_t /* f0 */, sv_frame_t /* f1 */) const {
        return "";
    }
    virtual QString toDelimitedDataStringSubsetWithOptions(QString delimiter, DataExportOptions, sv_frame_t f0, sv_frame_t f1) const {
        // Default implementation supports no options
        return toDelimitedDataStringSubset(delimiter, f0, f1);
    }

public slots:
    void aboutToDelete();
    void sourceModelAboutToBeDeleted();

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();

    /**
     * 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(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();

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

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

    /**
     * Emitted when something notifies this model (through calling
     * aboutToDelete() that it is about to delete it.  Note that this
     * depends on an external agent such as a Document object or
     * owning model telling the model that it is about to delete it;
     * there is nothing in the model to guarantee that this signal
     * will be emitted before the actual deletion.
     */
    void aboutToBeDeleted();

protected:
    Model() : 
        m_sourceModel(0), 
        m_alignment(0), 
        m_abandoning(false), 
        m_aboutToDelete(false) { }

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

    Model *m_sourceModel;
    AlignmentModel *m_alignment;
    QString m_typeUri;
    bool m_abandoning;
    bool m_aboutToDelete;
};

#endif