src/core/qgsscalecalculator.h

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/***************************************************************************
                          qgsscalecalculator.h
              Calculates scale based on map extent and units
                             -------------------
    begin                : May 18, 2004
    copyright            : (C) 2004 by Gary E.Sherman
    email                : sherman at mrcc.com
 ***************************************************************************/

/***************************************************************************
 *                                                                         *
 *   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.                                   *
 *                                                                         *
 ***************************************************************************/
/* $Id$ */

#ifndef QGSSCALECALCULATOR_H
#define QGSSCALECALCULATOR_H

#include <qgis.h>

class QString;
class QgsRectangle;

class CORE_EXPORT QgsScaleCalculator
{
  public:

    QgsScaleCalculator( double dpi = 0,
                        QGis::UnitType mapUnits = QGis::Meters );

    ~QgsScaleCalculator();

    void setDpi( double dpi );
    double dpi();

    void setMapUnits( QGis::UnitType mapUnits );

    QGis::UnitType mapUnits() const;

    double calculate( const QgsRectangle &mapExtent, int canvasWidth );

    double calculateGeographicDistance( const QgsRectangle &mapExtent );

  private:

    double mDpi;

    QGis::UnitType mMapUnits;
};

#endif // #ifndef QGSSCALECALCULATOR_H