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bbd36b107f
git-svn-id: http://svn.osgeo.org/qgis/trunk/qgis@6415 c8812cc2-4d05-0410-92ff-de0c093fc19c
60 lines
1.5 KiB
Plaintext
60 lines
1.5 KiB
Plaintext
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/**
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* \class QgsScaleCalculator
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* \brief Calculates scale for a given combination of canvas size, map extent,
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* and monitor dpi.
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*/
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class QgsScaleCalculator
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{
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%TypeHeaderCode
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#include <qgsscalecalculator.h>
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%End
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public:
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/**
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* Constructor
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* @param dpi Monitor resolution in dots per inch
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* @param mapUnits Units of the data on the map. Must match a value from the
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* QGis::units enum (METERS, FEET, DEGREES)
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*/
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QgsScaleCalculator(int dpi = 0,
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QGis::units mapUnits = QGis::METERS);
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//! Destructor
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~QgsScaleCalculator();
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/**
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* Set the dpi to be used in scale calculations
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* @param dpi Dots per inch of monitor resolution
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*/
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void setDpi(int dpi);
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/**
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* Set the map units
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* @param mapUnits Units of the data on the map. Must match a value from the
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*/
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void setMapUnits(QGis::units mapUnits);
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/** Returns current map units */
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QGis::units mapUnits() const;
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/**
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* Calculate the scale
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* @param mapExtent QgsRect containing the current map extent
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* @param canvasWidth Width of the map canvas in pixel (physical) units
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* @return scale of current map view
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*/
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double calculate(QgsRect &mapExtent, int canvasWidth);
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/**
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* Calculate the distance between to points in geographic coordinates.
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* Used to calculate scale for map views with geographic (decimal degree)
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* data.
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* @param mapExtent QgsRect containing the current map extent
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*/
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double calculateGeographicDistance(QgsRect &mapExtent);
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};
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