annotate base/UnitDatabase.h @ 537:3cc4b7cd2aa5

* Merge from one-fftdataserver-per-fftmodel branch.  This bit of
reworking (which is not described very accurately by the title of
the branch) turns the MatrixFile object into something that either
reads or writes, but not both, and separates the FFT file cache
reader and writer implementations separately.  This allows the
FFT data server to have a single thread owning writers and one reader
per "customer" thread, and for all locking to be vastly simplified
and concentrated in the data server alone (because none of the
classes it makes use of is used in more than one thread at a time).
The result is faster and more trustworthy code.

/* -*- 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 _UNIT_DATABASE_H_
#define _UNIT_DATABASE_H_

#include <QObject>
#include <QString>
#include <QStringList>
#include <map>

// This grandly named class is just a list of the names of known scale
// units for the various models, for use as the set of fixed values in
// unit dropdown menus etc.  Of course, the user should be allowed to
// enter their own as well.

class UnitDatabase : public QObject
{
    Q_OBJECT

public:
    static UnitDatabase *getInstance();

    QStringList getKnownUnits() const;
    void registerUnit(QString unit);

    /**
     * Return the reference id for a given unit name.  If registerNew is
     * true and the unit is not known, register it and return its new
     * id.  If register is false and the unit is not known, return -1.
     */
    int getUnitId(QString unit, bool registerNew = true);

    QString getUnitById(int id);

signals:
    void unitDatabaseChanged();

protected:
    UnitDatabase();

    typedef std::map<QString, int> UnitMap;
    UnitMap m_units;
    int m_nextId;

    static UnitDatabase m_instance;
};

#endif