annotate base/UnitDatabase.h @ 335:02d2ad95ea52 spectrogram-cache-rejig

* Get storage advice for each cache in an FFT data server.  Allows us to be
  more confident about the actual memory situation and cut over from memory
  to disc part way through an FFT calculation if necessary.  StorageAdviser
  is now a bit too optimistic though (it's too keen to allocate large numbers
  of small blocks in memory).

/* -*- 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