QGIS API Documentation 3.27.0-Master (0a97e3138f)
qgsscalecalculator.h
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1/***************************************************************************
2 qgsscalecalculator.h
3 Calculates scale based on map extent and units
4 -------------------
5 begin : May 18, 2004
6 copyright : (C) 2004 by Gary E.Sherman
7 email : sherman at mrcc.com
8 ***************************************************************************/
9
10/***************************************************************************
11 * *
12 * This program is free software; you can redistribute it and/or modify *
13 * it under the terms of the GNU General Public License as published by *
14 * the Free Software Foundation; either version 2 of the License, or *
15 * (at your option) any later version. *
16 * *
17 ***************************************************************************/
18
19#ifndef QGSSCALECALCULATOR_H
20#define QGSSCALECALCULATOR_H
21
22#include "qgis_core.h"
23#include "qgis_sip.h"
24#include "qgsunittypes.h"
25
26class QString;
27class QgsRectangle;
28
34class CORE_EXPORT QgsScaleCalculator
35{
36 public:
37
43 QgsScaleCalculator( double dpi = 0,
45
50 void setDpi( double dpi );
51
56 double dpi() const;
57
62 void setMapUnits( QgsUnitTypes::DistanceUnit mapUnits );
63
65 QgsUnitTypes::DistanceUnit mapUnits() const;
66
73 double calculate( const QgsRectangle &mapExtent, double canvasWidth ) const;
74
82 QSizeF calculateImageSize( const QgsRectangle &mapExtent, double scale ) const;
83
90 double calculateGeographicDistance( const QgsRectangle &mapExtent ) const;
91
92 private:
93
95 void calculateMetrics( const QgsRectangle &mapExtent, double &delta, double &conversionFactor ) const;
96
98 double mDpi;
99
102};
103
104#endif // #ifndef QGSSCALECALCULATOR_H
A rectangle specified with double values.
Definition: qgsrectangle.h:42
Calculates scale for a given combination of canvas size, map extent, and monitor dpi.
DistanceUnit
Units of distance.
Definition: qgsunittypes.h:68
@ DistanceMeters
Meters.
Definition: qgsunittypes.h:69