QgsCRSCache Class Reference

Caches QgsCoordinateReferenceSystem construction, which may be expensive. More...

#include <qgscrscache.h>

Public Member Functions
Q_DECL_DEPRECATED QgsCoordinateReferenceSystem	crsByAuthId (const QString &authid)
	Returns the CRS for authid, e.g. More...
QgsCoordinateReferenceSystem	crsByEpsgId (long epsg) const
	Returns the CRS from a given EPSG ID. More...
QgsCoordinateReferenceSystem	crsByOgcWmsCrs (const QString &ogcCrs) const
	Returns the CRS from a given OGC WMS-format Coordinate Reference System string. More...
QgsCoordinateReferenceSystem	crsByProj4 (const QString &proj4) const
	Returns the CRS from a proj4 style formatted string. More...
QgsCoordinateReferenceSystem	crsBySrsId (long srsId) const
	Returns the CRS from a specified QGIS SRS ID. More...
QgsCoordinateReferenceSystem	crsByWkt (const QString &wkt) const
	Returns the CRS from a WKT spatial ref sys definition string. More...
void	updateCRSCache (const QString &authid)
	Updates the cached definition of a CRS. More...

Static Public Member Functions
static QgsCRSCache *	instance ()
	Returns a pointer to the QgsCRSCache singleton. More...

Protected Member Functions
	QgsCRSCache ()

Detailed Description

Caches QgsCoordinateReferenceSystem construction, which may be expensive.

QgsCRSCache maintains a cache of previously constructed coordinate systems, so that creating a new CRS from the cache can reuse previously calculated parameters. The constructors for QgsCoordinateReferenceSystem can be expensive, so it's recommended to use QgsCRSCache instead of directly calling the QgsCoordinateReferenceSystem constructors.

Definition at line 67 of file qgscrscache.h.

Constructor & Destructor Documentation

QgsCRSCache()

QgsCRSCache::QgsCRSCache ( )

protected

Definition at line 97 of file qgscrscache.cpp.

Member Function Documentation

crsByAuthId()

QgsCoordinateReferenceSystem QgsCRSCache::crsByAuthId

(

const QString &

authid

)

Returns the CRS for authid, e.g.

'EPSG:4326' (or an invalid CRS in case of error)

Deprecated:

use crsByOgcWmsCrs() instead

Definition at line 120 of file qgscrscache.cpp.

crsByEpsgId()

QgsCoordinateReferenceSystem QgsCRSCache::crsByEpsgId

(

long

epsg

)

const

Returns the CRS from a given EPSG ID.

Parameters

epsg	epsg CRS ID

Returns

matching CRS, or an invalid CRS if string could not be matched

Definition at line 155 of file qgscrscache.cpp.

crsByOgcWmsCrs()

QgsCoordinateReferenceSystem QgsCRSCache::crsByOgcWmsCrs

(

const QString &

ogcCrs

)

const

Returns the CRS from a given OGC WMS-format Coordinate Reference System string.

Parameters

ogcCrs

OGR compliant CRS definition, eg "EPSG:4326"

Returns

matching CRS, or an invalid CRS if string could not be matched

Note

added in QGIS 2.16

See also

QgsCoordinateReferenceSystem::createFromOgcWmsCrs()

Definition at line 125 of file qgscrscache.cpp.

crsByProj4()

QgsCoordinateReferenceSystem QgsCRSCache::crsByProj4

(

const QString &

proj4

)

const

Returns the CRS from a proj4 style formatted string.

Parameters

proj4

proj4 format string

Returns

matching CRS, or an invalid CRS if string could not be matched

Note

added in QGIS 2.16

See also

QgsCoordinateReferenceSystem::createFromProj4()

Definition at line 160 of file qgscrscache.cpp.

crsBySrsId()

QgsCoordinateReferenceSystem QgsCRSCache::crsBySrsId

(

long

srsId

)

const

Returns the CRS from a specified QGIS SRS ID.

Parameters

srsId

internal QGIS SRS ID

Returns

matching CRS, or an invalid CRS if ID could not be found

Note

added in QGIS 2.16

See also

QgsCoordinateReferenceSystem::createFromSrsId()

Definition at line 220 of file qgscrscache.cpp.

crsByWkt()

QgsCoordinateReferenceSystem QgsCRSCache::crsByWkt

(

const QString &

wkt

)

const

Returns the CRS from a WKT spatial ref sys definition string.

Parameters

wkt	WKT for the desired spatial reference system.

Returns

matching CRS, or an invalid CRS if string could not be matched

Note

added in QGIS 2.16

See also

QgsCoordinateReferenceSystem::createFromWkt()

Definition at line 190 of file qgscrscache.cpp.

instance()

QgsCRSCache * QgsCRSCache::instance ( )

static

Returns a pointer to the QgsCRSCache singleton.

Definition at line 91 of file qgscrscache.cpp.

updateCRSCache()

void QgsCRSCache::updateCRSCache

(

const QString &

authid

)

Updates the cached definition of a CRS.

Should be called if the definition of a user-created CRS has been changed.

Parameters

authid

CRS auth ID, eg "EPSG:4326" or "USER:100009"

Definition at line 104 of file qgscrscache.cpp.

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The documentation for this class was generated from the following files:

• /tmp/buildd/qgis-2.18.21+99unstable/src/core/qgscrscache.h
• /tmp/buildd/qgis-2.18.21+99unstable/src/core/qgscrscache.cpp