Utility functions for working with the proj library. More...

#include <qgsprojutils.h>

Classes
struct	ProjPJDeleter
	Destroys Proj PJ objects. More...

Public Types
enum	IdentifyFlag { FlagMatchBoundCrsToUnderlyingSourceCrs = 1 << 0 }
	Flags controlling CRS identification behavior. More...

typedef QFlags< IdentifyFlag >	IdentifyFlags

using	proj_pj_unique_ptr = std::unique_ptr< PJ, ProjPJDeleter >
	Scoped Proj PJ object.

Static Public Member Functions
static bool	axisOrderIsSwapped (const PJ *crs)
	Returns `true` if the given proj coordinate system uses requires y/x coordinate order instead of x/y.

static bool	coordinateOperationIsAvailable (const QString &projDef)
	Returns `true` if a coordinate operation (specified via proj string) is available.

static proj_pj_unique_ptr	createCompoundCrs (const PJ horizontalCrs, const PJ verticalCrs, QStringList *errors=nullptr)
	Given a PROJ horizontal and vertical CRS, attempt to create a compound CRS from them.

static proj_pj_unique_ptr	crsToDatumEnsemble (const PJ *crs)
	Given a PROJ crs, attempt to retrieve the datum ensemble from it.

static proj_pj_unique_ptr	crsToHorizontalCrs (const PJ *crs)
	Given a PROJ crs (which may be a compound or bound crs, or some other type), extract the horizontal crs from it.

static proj_pj_unique_ptr	crsToVerticalCrs (const PJ *crs)
	Given a PROJ crs (which may be a compound crs, or some other type), extract the vertical crs from it.

static QDate	epsgRegistryDate ()
	Returns the EPSG registry database release date used by the proj library.

static QString	epsgRegistryVersion ()
	Returns the EPSG registry database version used by the proj library (e.g.

static QDate	esriDatabaseDate ()
	Returns the ESRI projection engine database release date used by the proj library.

static QString	esriDatabaseVersion ()
	Returns the ESRI projection engine database version used by the proj library (e.g.

static QList< QgsDatumTransform::GridDetails >	gridsUsed (const QString &proj)
	Returns a list of grids used by the given proj string.

static bool	hasVerticalAxis (const PJ *crs)
	Returns `true` if a PROJ crs has a vertical axis.

static bool	identifyCrs (const PJ *crs, QString &authName, QString &authCode, IdentifyFlags flags=IdentifyFlags())
	Attempts to identify a crs, matching it to a known authority and code within an acceptable level of tolerance.

static QDate	ignfDatabaseDate ()
	Returns the IGNF database release date used by the proj library.

static QString	ignfDatabaseVersion ()
	Returns the IGNF database version used by the proj library (e.g.

static bool	isDynamic (const PJ *crs)
	Returns `true` if the given proj coordinate system is a dynamic CRS.

static void	proj_collecting_logger (void user_data, int level, const char message)
	QGIS proj log function which collects errors to a QStringList.

static void	proj_logger (void user_data, int level, const char message)
	Default QGIS proj log function.

static int	projVersionMajor ()
	Returns the proj library major version number.

static int	projVersionMinor ()
	Returns the proj library minor version number.

static QStringList	searchPaths ()
	Returns the current list of Proj file search paths.

static proj_pj_unique_ptr	unboundCrs (const PJ *crs)
	Given a PROJ crs (which may be a compound or bound crs, or some other type), ensure that it is not a bound CRS object.

static bool	usesAngularUnit (const QString &projDef)
	Returns `true` if the given proj coordinate system uses angular units.

Detailed Description

Utility functions for working with the proj library.

Since: QGIS 3.8

Definition at line 44 of file qgsprojutils.h.

Member Typedef Documentation

◆ IdentifyFlags

typedef QFlags< IdentifyFlag > QgsProjUtils::IdentifyFlags

Definition at line 123 of file qgsprojutils.h.

◆ proj_pj_unique_ptr

using QgsProjUtils::proj_pj_unique_ptr = std::unique_ptr< PJ, ProjPJDeleter >

Scoped Proj PJ object.

Definition at line 141 of file qgsprojutils.h.

Member Enumeration Documentation

◆ IdentifyFlag

enum QgsProjUtils::IdentifyFlag

Flags controlling CRS identification behavior.

Enumerator
FlagMatchBoundCrsToUnderlyingSourceCrs	Allow matching a BoundCRS object to its underlying SourceCRS.

Definition at line 119 of file qgsprojutils.h.

Member Function Documentation

◆ axisOrderIsSwapped()

bool QgsProjUtils::axisOrderIsSwapped ( const PJ * crs )

static

Returns true if the given proj coordinate system uses requires y/x coordinate order instead of x/y.

Definition at line 113 of file qgsprojutils.cpp.

◆ coordinateOperationIsAvailable()

bool QgsProjUtils::coordinateOperationIsAvailable ( const QString & projDef )

static

Returns true if a coordinate operation (specified via proj string) is available.

Definition at line 468 of file qgsprojutils.cpp.

◆ createCompoundCrs()

QgsProjUtils::proj_pj_unique_ptr QgsProjUtils::createCompoundCrs	(	const PJ *	horizontalCrs,
		const PJ *	verticalCrs,
		QStringList *	errors = `nullptr`
	)

static

Given a PROJ horizontal and vertical CRS, attempt to create a compound CRS from them.

Optionally, the errors argument can be set to a string list to collect errors reported by PROJ when attempting to create the compound CRS.

Since: QGIS 3.38

Definition at line 392 of file qgsprojutils.cpp.

◆ crsToDatumEnsemble()

QgsProjUtils::proj_pj_unique_ptr QgsProjUtils::crsToDatumEnsemble ( const PJ * crs )

static

Given a PROJ crs, attempt to retrieve the datum ensemble from it.

Note: In the case of a compound crs, this method will always return the datum ensemble for the horizontal component.

Warning: This method requires PROJ 8.0 or later

Exceptions

QgsNotSupportedException on QGIS builds based on PROJ 7 or earlier.

Since: QGIS 3.20

Definition at line 338 of file qgsprojutils.cpp.

◆ crsToHorizontalCrs()

QgsProjUtils::proj_pj_unique_ptr QgsProjUtils::crsToHorizontalCrs ( const PJ * crs )

static

Given a PROJ crs (which may be a compound or bound crs, or some other type), extract the horizontal crs from it.

If crs does not contain a horizontal CRS (i.e. it is a vertical CRS) nullptr will be returned.

See also: crsToVerticalCrs()

Definition at line 193 of file qgsprojutils.cpp.

◆ crsToVerticalCrs()

QgsProjUtils::proj_pj_unique_ptr QgsProjUtils::crsToVerticalCrs ( const PJ * crs )

static

Given a PROJ crs (which may be a compound crs, or some other type), extract the vertical crs from it.

If crs does not contain a vertical CRS (i.e. it is a horizontal CRS) nullptr will be returned.

See also: crsToHorizontalCrs()

Since: QGIS 3.38

Definition at line 227 of file qgsprojutils.cpp.

◆ epsgRegistryDate()

QDate QgsProjUtils::epsgRegistryDate ( )

static

Returns the EPSG registry database release date used by the proj library.

See also: epsgRegistryVersion()

Since: QGIS 3.20

Definition at line 552 of file qgsprojutils.cpp.

◆ epsgRegistryVersion()

QString QgsProjUtils::epsgRegistryVersion ( )

static

Returns the EPSG registry database version used by the proj library (e.g.

"v9.8.6").

See also: epsgRegistryDate()

Since: QGIS 3.20

Definition at line 545 of file qgsprojutils.cpp.

◆ esriDatabaseDate()

QDate QgsProjUtils::esriDatabaseDate ( )

static

Returns the ESRI projection engine database release date used by the proj library.

See also: esriDatabaseVersion()

Since: QGIS 3.20

Definition at line 566 of file qgsprojutils.cpp.

◆ esriDatabaseVersion()

QString QgsProjUtils::esriDatabaseVersion ( )

static

Returns the ESRI projection engine database version used by the proj library (e.g.

"ArcMap 10.8.0").

See also: esriDatabaseDate()

Since: QGIS 3.20

Definition at line 559 of file qgsprojutils.cpp.

◆ gridsUsed()

QList< QgsDatumTransform::GridDetails > QgsProjUtils::gridsUsed ( const QString & proj )

static

Returns a list of grids used by the given proj string.

Definition at line 481 of file qgsprojutils.cpp.

◆ hasVerticalAxis()

bool QgsProjUtils::hasVerticalAxis ( const PJ * crs )

static

Returns true if a PROJ crs has a vertical axis.

Since: QGIS 3.38

Definition at line 259 of file qgsprojutils.cpp.

◆ identifyCrs()

bool QgsProjUtils::identifyCrs	(	const PJ *	crs,
		QString &	authName,
		QString &	authCode,
		IdentifyFlags	flags = `IdentifyFlags()`
	)

static

Attempts to identify a crs, matching it to a known authority and code within an acceptable level of tolerance.

Returns true if a matching authority and code was found.

Definition at line 414 of file qgsprojutils.cpp.

◆ ignfDatabaseDate()

QDate QgsProjUtils::ignfDatabaseDate ( )

static

Returns the IGNF database release date used by the proj library.

See also: ignfDatabaseVersion()

Since: QGIS 3.20

Definition at line 580 of file qgsprojutils.cpp.

◆ ignfDatabaseVersion()

QString QgsProjUtils::ignfDatabaseVersion ( )

static

Returns the IGNF database version used by the proj library (e.g.

"3.1.0").

See also: ignfDatabaseDate()

Since: QGIS 3.20

Definition at line 573 of file qgsprojutils.cpp.

◆ isDynamic()

bool QgsProjUtils::isDynamic ( const PJ * crs )

static

Returns true if the given proj coordinate system is a dynamic CRS.

A dynamic CRS relies on a dynamic datum, that is a datum that is not plate-fixed.

Since: QGIS 3.20

Definition at line 149 of file qgsprojutils.cpp.

◆ proj_collecting_logger()

void QgsProjUtils::proj_collecting_logger	(	void *	user_data,
		int	level,
		const char *	message
	)

static

QGIS proj log function which collects errors to a QStringList.

Warning: The user_data argument passed to proj_log_func MUST be a QStringList object, and must exist for the duration where proj_collecting_logger is used. You MUST reset the proj_log_func to proj_logger before the user data QStringList is destroyed.

Definition at line 358 of file qgsprojutils.cpp.

◆ proj_logger()

void QgsProjUtils::proj_logger	(	void *	user_data,
		int	level,
		const char *	message
	)

static

Default QGIS proj log function.

Uses QgsDebugError or QgsDebugMsgLevel to report errors in debug builds only.

Definition at line 366 of file qgsprojutils.cpp.

◆ projVersionMajor()

int QgsProjUtils::projVersionMajor ( )

static

Returns the proj library major version number.

Definition at line 535 of file qgsprojutils.cpp.

◆ projVersionMinor()

int QgsProjUtils::projVersionMinor ( )

static

Returns the proj library minor version number.

Since: QGIS 3.20

Definition at line 540 of file qgsprojutils.cpp.

◆ searchPaths()

QStringList QgsProjUtils::searchPaths ( )

static

Returns the current list of Proj file search paths.

Note: Only available on builds based on Proj >= 6.0. Builds based on earlier Proj versions will always return an empty list.

Definition at line 587 of file qgsprojutils.cpp.

◆ unboundCrs()

QgsProjUtils::proj_pj_unique_ptr QgsProjUtils::unboundCrs ( const PJ * crs )

static

Given a PROJ crs (which may be a compound or bound crs, or some other type), ensure that it is not a bound CRS object.

Bound CRS objects will be returned as their source CRS, other types will be returned as a direct clone.

Definition at line 316 of file qgsprojutils.cpp.

◆ usesAngularUnit()

bool QgsProjUtils::usesAngularUnit ( const QString & projDef )

static

Returns true if the given proj coordinate system uses angular units.

projDef must be a proj string defining a CRS object.

Definition at line 74 of file qgsprojutils.cpp.

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

/build/qgis-3.41.0+git20241122+3440c17df1d+99sid/src/core/proj/qgsprojutils.h
/build/qgis-3.41.0+git20241122+3440c17df1d+99sid/src/core/proj/qgsprojutils.cpp

Classes

Public Types

Static Public Member Functions

Detailed Description

Member Typedef Documentation

◆ IdentifyFlags

◆ proj_pj_unique_ptr

Member Enumeration Documentation

◆ IdentifyFlag

Member Function Documentation

◆ axisOrderIsSwapped()

◆ coordinateOperationIsAvailable()

◆ createCompoundCrs()

◆ crsToDatumEnsemble()

◆ crsToHorizontalCrs()

◆ crsToVerticalCrs()

◆ epsgRegistryDate()

◆ epsgRegistryVersion()

◆ esriDatabaseDate()

◆ esriDatabaseVersion()

◆ gridsUsed()

◆ hasVerticalAxis()

◆ identifyCrs()

◆ ignfDatabaseDate()

◆ ignfDatabaseVersion()

◆ isDynamic()

◆ proj_collecting_logger()

◆ proj_logger()

◆ projVersionMajor()

◆ projVersionMinor()

◆ searchPaths()

◆ unboundCrs()

◆ usesAngularUnit()