view data/model/WritableWaveFileModel.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 QMUL.
    
    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 WRITABLE_WAVE_FILE_MODEL_H
#define WRITABLE_WAVE_FILE_MODEL_H

#include "WaveFileModel.h"
#include "ReadOnlyWaveFileModel.h"
#include "PowerOfSqrtTwoZoomConstraint.h"

class WavFileWriter;
class WavFileReader;

class WritableWaveFileModel : public WaveFileModel
{
    Q_OBJECT

public:
    WritableWaveFileModel(sv_samplerate_t sampleRate, int channels, QString path = "");
    ~WritableWaveFileModel();

    /**
     * Call addSamples to append a block of samples to the end of the
     * file.
     *
     * This function only appends the samples to the file being
     * written; it does not update the model's view of the samples in
     * that file. That is, it updates the file on disc but the model
     * itself does not change its content. This is because re-reading
     * the file to update the model may be more expensive than adding
     * the samples in the first place. If you are writing small
     * numbers of samples repeatedly, you probably only want the model
     * to update periodically rather than after every write.
     *
     * Call updateModel() periodically to tell the model to update its
     * own view of the samples in the file being written.
     *
     * Call setWriteProportion() periodically if the file being
     * written has known duration and you want the model to be able to
     * report the write progress as a percentage.
     *
     * Call writeComplete() when the file has been completely written.
     */
    virtual bool addSamples(const float *const *samples, sv_frame_t count);

    /**
     * Tell the model to update its own (read) view of the (written)
     * file. May cause modelChanged() and modelChangedWithin() to be
     * emitted. See the comment to addSamples above for rationale.
     */
    void updateModel();
    
    /**
     * Set the proportion of the file which has been written so far,
     * as a percentage. This may be used to indicate progress.
     *
     * Note that this differs from the "completion" percentage
     * reported through isReady()/getCompletion(). That percentage is
     * updated when "internal processing has advanced... but the model
     * has not changed externally", i.e. it reports progress in
     * calculating the initial state of a model. In contrast, an
     * update to setWriteProportion corresponds to a change in the
     * externally visible state of the model (i.e. it contains more
     * data than before).
     */
    void setWriteProportion(int proportion);

    /**
     * Indicate that writing is complete. You should call this even if
     * you have never called setWriteProportion() or updateModel().
     */
    void writeComplete();

    static const int PROPORTION_UNKNOWN;
    
    /**
     * Get the proportion of the file which has been written so far,
     * as a percentage. Return PROPORTION_UNKNOWN if unknown.
     */
    int getWriteProportion() const;
    
    bool isOK() const;
    bool isReady(int *) const;
    
    /**
     * Return the generation completion percentage of this model. This
     * is always 100, because the model is always in a complete state
     * -- it just contains varying amounts of data depending on how
     * much has been written.
     */
    virtual int getCompletion() const { return 100; }

    const ZoomConstraint *getZoomConstraint() const {
        static PowerOfSqrtTwoZoomConstraint zc;
        return &zc;
    }

    sv_frame_t getFrameCount() const;
    int getChannelCount() const { return m_channels; }
    sv_samplerate_t getSampleRate() const { return m_sampleRate; }
    sv_samplerate_t getNativeRate() const { return m_sampleRate; }

    QString getTitle() const {
        if (m_model) return m_model->getTitle();
        else return "";
    } 
    QString getMaker() const {
        if (m_model) return m_model->getMaker();
        else return "";
    }
    QString getLocation() const {
        if (m_model) return m_model->getLocation();
        else return "";
    }

    float getValueMinimum() const { return -1.0f; }
    float getValueMaximum() const { return  1.0f; }

    virtual sv_frame_t getStartFrame() const { return m_startFrame; }
    virtual sv_frame_t getEndFrame() const { return m_startFrame + getFrameCount(); }

    void setStartFrame(sv_frame_t startFrame);

    virtual floatvec_t getData(int channel, sv_frame_t start, sv_frame_t count) const;

    virtual std::vector<floatvec_t> getMultiChannelData(int fromchannel, int tochannel, sv_frame_t start, sv_frame_t count) const;

    virtual int getSummaryBlockSize(int desired) const;

    virtual void getSummaries(int channel, sv_frame_t start, sv_frame_t count,
                              RangeBlock &ranges, int &blockSize) const;

    virtual Range getSummary(int channel, sv_frame_t start, sv_frame_t count) const;

    QString getTypeName() const { return tr("Writable Wave File"); }

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

protected:
    ReadOnlyWaveFileModel *m_model;
    WavFileWriter *m_writer;
    WavFileReader *m_reader;
    sv_samplerate_t m_sampleRate;
    int m_channels;
    sv_frame_t m_frameCount;
    sv_frame_t m_startFrame;
    int m_proportion;
};

#endif