view base/UnitDatabase.h @ 492:23945cdd7161

* Update RDF query stuff again so as to set up a temporary datastore
  each time we want to query over an rdf file, instead of using rasqal
  against the file.  Seems the only way to avoid threading and storage
  management issues when trying to load from a single-source file and
  perform queries against our main datastore at the same time.  Maybe.

/* -*- 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