QGIS API Documentation
2.12.0-Lyon
|
Class for storing a coordinate reference system (CRS) More...
#include <qgscoordinatereferencesystem.h>
Public Types | |
enum | CrsType { InternalCrsId, PostgisCrsId, EpsgCrsId } |
Public Member Functions | |
QgsCoordinateReferenceSystem () | |
Default constructor. More... | |
QgsCoordinateReferenceSystem (const QString &theDefinition) | |
QgsCoordinateReferenceSystem (const long theId, CrsType theType=PostgisCrsId) | |
Use this constructor when you want to create a CRS object using a postgis SRID, an EpsgCrsId id or a QGIS CRS_ID. More... | |
QgsCoordinateReferenceSystem (const QgsCoordinateReferenceSystem &srs) | |
copy constructor More... | |
~QgsCoordinateReferenceSystem () | |
QString | authid () const |
Get the authority identifier for this srs. More... | |
bool | axisInverted () const |
Return if axis is inverted (eg. More... | |
bool | createFromId (const long theId, CrsType theType=PostgisCrsId) |
bool | createFromOgcWmsCrs (QString theCrs) |
Set up this CRS from the given OGC CRS. More... | |
bool | createFromProj4 (const QString &theProjString) |
Set up this srs by passing it a proj4 style formatted string. More... | |
bool | createFromSrid (const long theSrid) |
Set up this srs by fetching the appropriate information from the sqlite backend. More... | |
bool | createFromSrsId (const long theSrsId) |
Set up this srs by fetching the appropriate information from the sqlite backend. More... | |
bool | createFromString (const QString &theDefinition) |
Set up this srs from a string definition, by default a WKT definition. More... | |
bool | createFromUserInput (const QString &theDefinition) |
Set up this srs from a various text formats. More... | |
bool | createFromWkt (const QString &theWkt) |
Set up this srs using a Wkt spatial ref sys definition. More... | |
QString | description () const |
Get the Description. More... | |
QString | ellipsoidAcronym () const |
Get the Ellipsoid Acronym. More... | |
long | findMatchingProj () |
This is a globbing function to try to find a record in the database that matches a CRS defined only by a proj4string. More... | |
QString | geographicCRSAuthId () const |
Returns auth id of related geographic CRS. More... | |
bool | geographicFlag () const |
Get this Geographic? flag. More... | |
bool | isValid () const |
Find out whether this CRS is correctly initialised and usable. More... | |
QGis::UnitType | mapUnits () const |
Get the units that the projection is in. More... | |
bool | operator!= (const QgsCoordinateReferenceSystem &theSrs) const |
Overloaded != operator used to compare to CRS's. More... | |
QgsCoordinateReferenceSystem & | operator= (const QgsCoordinateReferenceSystem &srs) |
Assignment operator. More... | |
bool | operator== (const QgsCoordinateReferenceSystem &theSrs) const |
Overloaded == operator used to compare to CRS's. More... | |
long | postgisSrid () const |
Get the postgis srid for this srs. More... | |
QString | projectionAcronym () const |
Get the Projection Acronym. More... | |
bool | readXML (QDomNode &theNode) |
Restores state from the given Dom node. More... | |
bool | saveAsUserCRS (const QString &name) |
Save the proj4-string as a custom CRS. More... | |
void | setValidationHint (const QString &html) |
Set user hint for validation. More... | |
long | srsid () const |
Get the SrsId - if possible. More... | |
QString | toProj4 () const |
Get the Proj Proj4 string representation of this srs. More... | |
QString | toWkt () const |
A helper to get an wkt representation of this srs. More... | |
void | validate () |
Perform some validation on this CRS. More... | |
QString | validationHint () |
Get user hint for validation. More... | |
bool | writeXML (QDomNode &theNode, QDomDocument &theDoc) const |
Stores state to the given Dom node in the given document. More... | |
Static Public Member Functions | |
static CUSTOM_CRS_VALIDATION | customSrsValidation () |
Gets custom function. More... | |
static QStringList | recentProjections () |
Returns a list of recently used projections. More... | |
static void | setCustomSrsValidation (CUSTOM_CRS_VALIDATION f) |
Sets custom function to force valid CRS QGIS uses implementation in QgisGui::customSrsValidation. More... | |
static void | setupESRIWktFix () |
Make sure that ESRI WKT import is done properly. More... | |
static int | syncDb () |
Update proj.4 parameters in our database from proj.4. More... | |
Class for storing a coordinate reference system (CRS)
Definition at line 50 of file qgscoordinatereferencesystem.h.
QgsCoordinateReferenceSystem::QgsCoordinateReferenceSystem | ( | ) |
Default constructor.
Definition at line 52 of file qgscoordinatereferencesystem.cpp.
QgsCoordinateReferenceSystem::~QgsCoordinateReferenceSystem | ( | ) |
Definition at line 91 of file qgscoordinatereferencesystem.cpp.
|
explicit |
Constructs a CRS object from a string definition as defined in the createFromString member function (by default a WKT definition).
theDefinition | A String containing a coordinate reference system definition. |
Definition at line 64 of file qgscoordinatereferencesystem.cpp.
QgsCoordinateReferenceSystem::QgsCoordinateReferenceSystem | ( | const long | theId, |
CrsType | theType = PostgisCrsId |
||
) |
Use this constructor when you want to create a CRS object using a postgis SRID, an EpsgCrsId id or a QGIS CRS_ID.
theId | The ID no valid for the chosen coordinate system id type |
theType | One of the types described in QgsCoordinateReferenceSystem::CrsType |
Definition at line 78 of file qgscoordinatereferencesystem.cpp.
QgsCoordinateReferenceSystem::QgsCoordinateReferenceSystem | ( | const QgsCoordinateReferenceSystem & | srs | ) |
copy constructor
Definition at line 258 of file qgscoordinatereferencesystem.cpp.
QString QgsCoordinateReferenceSystem::authid | ( | ) | const |
Get the authority identifier for this srs.
Definition at line 834 of file qgscoordinatereferencesystem.cpp.
bool QgsCoordinateReferenceSystem::axisInverted | ( | ) | const |
Return if axis is inverted (eg.
for WMS 1.3)
Definition at line 405 of file qgscoordinatereferencesystem.cpp.
bool QgsCoordinateReferenceSystem::createFromId | ( | const long | theId, |
CrsType | theType = PostgisCrsId |
||
) |
Definition at line 96 of file qgscoordinatereferencesystem.cpp.
bool QgsCoordinateReferenceSystem::createFromOgcWmsCrs | ( | QString | theCrs | ) |
Set up this CRS from the given OGC CRS.
Sets this CRS to the given OGC WMS-format Coordinate Reference Systems.
false | if not given an valid label |
Definition at line 211 of file qgscoordinatereferencesystem.cpp.
bool QgsCoordinateReferenceSystem::createFromProj4 | ( | const QString & | theProjString | ) |
Set up this srs by passing it a proj4 style formatted string.
The string will be parsed and the projection and ellipsoid members set and the remainder of the proj4 string will be stored in the parameters member. The reason for this is so that we can easily present the user with 'natural language' representation of the projection and ellipsoid by looking them up in the srs.bs sqlite database. Also having the ellipse and proj elements stripped out is helpful to speed up globbing queries (see below).
We try to match the proj string to and srsid using the following logic:
theProjString | A proj4 format string |
Definition at line 512 of file qgscoordinatereferencesystem.cpp.
bool QgsCoordinateReferenceSystem::createFromSrid | ( | const long | theSrid | ) |
Set up this srs by fetching the appropriate information from the sqlite backend.
First the system level read only srs.db will be checked and then the users ~/.qgis/qgis.db database will be checked for a match.
theSrid | The postgis SRID for the desired spatial reference system. |
Definition at line 309 of file qgscoordinatereferencesystem.cpp.
bool QgsCoordinateReferenceSystem::createFromSrsId | ( | const long | theSrsId | ) |
Set up this srs by fetching the appropriate information from the sqlite backend.
If the srsid is < 100000, only the system srs.db will be checked. If the srsid > 100000 the srs will be retrieved from the ~/.qgis/qgis.db
theSrsId | The QGIS SrsId for the desired spatial reference system. |
Definition at line 314 of file qgscoordinatereferencesystem.cpp.
bool QgsCoordinateReferenceSystem::createFromString | ( | const QString & | theDefinition | ) |
Set up this srs from a string definition, by default a WKT definition.
Otherwise the string defines a authority, followed by a colon, followed by the definition. The authority can be one of "epsg", "postgis", "internal" for integer definitions, and "wkt" or "proj4" for string definitions. The implementation of each authority uses the corresponding createFrom... function.
theDefinition | A String containing a coordinate reference system definition. |
Definition at line 117 of file qgscoordinatereferencesystem.cpp.
bool QgsCoordinateReferenceSystem::createFromUserInput | ( | const QString & | theDefinition | ) |
Set up this srs from a various text formats.
Valid formats: WKT string, "EPSG:n", "EPSGA:n", "AUTO:proj_id,unit_id,lon0,lat0", "urn:ogc:def:crs:EPSG::n", PROJ.4 string, filename (with WKT, XML or PROJ.4 string), well known name (such as NAD27, NAD83, WGS84 or WGS72), ESRI::[WKT string] (directly or in a file), "IGNF:xxx"
For more details on supported formats see OGRSpatialReference::SetFromUserInput() ( http://www.gdal.org/ogr/classOGRSpatialReference.html#aec3c6a49533fe457ddc763d699ff8796 )
theDefinition | A String containing a coordinate reference system definition. |
Definition at line 161 of file qgscoordinatereferencesystem.cpp.
bool QgsCoordinateReferenceSystem::createFromWkt | ( | const QString & | theWkt | ) |
Set up this srs using a Wkt spatial ref sys definition.
The wkt will be converted to a proj4 string using OGR helper functions. After this the srs databasses will be searched for matches. First the system level read only srs.db will be checked and then the users ~/.qgis/qgis.db database will be checked for a match.
theWkt | The Wkt for the desired spatial reference system. |
Definition at line 431 of file qgscoordinatereferencesystem.cpp.
|
static |
Gets custom function.
Definition at line 1414 of file qgscoordinatereferencesystem.cpp.
QString QgsCoordinateReferenceSystem::description | ( | ) | const |
Get the Description.
Definition at line 839 of file qgscoordinatereferencesystem.cpp.
QString QgsCoordinateReferenceSystem::ellipsoidAcronym | ( | ) | const |
Get the Ellipsoid Acronym.
Definition at line 863 of file qgscoordinatereferencesystem.cpp.
long QgsCoordinateReferenceSystem::findMatchingProj | ( | ) |
This is a globbing function to try to find a record in the database that matches a CRS defined only by a proj4string.
The goal is to learn what the tbl_srs.srs_id value is for the CRS. Internally the source CRS is converted to an OGR srs object using the proj4string call and then every record in the database that matches projection and ellipsoid will be converted to an OGR srs in turn and compared to the source CRS. There are some gotchas with using ogr isSame() srs comparison, but its more effective than using straight string comparison of proj4params.
Definition at line 1021 of file qgscoordinatereferencesystem.cpp.
QString QgsCoordinateReferenceSystem::geographicCRSAuthId | ( | ) | const |
Returns auth id of related geographic CRS.
Definition at line 2146 of file qgscoordinatereferencesystem.cpp.
bool QgsCoordinateReferenceSystem::geographicFlag | ( | ) | const |
Get this Geographic? flag.
Definition at line 892 of file qgscoordinatereferencesystem.cpp.
bool QgsCoordinateReferenceSystem::isValid | ( | ) | const |
Find out whether this CRS is correctly initialised and usable.
Definition at line 507 of file qgscoordinatereferencesystem.cpp.
QGis::UnitType QgsCoordinateReferenceSystem::mapUnits | ( | ) | const |
Get the units that the projection is in.
Definition at line 897 of file qgscoordinatereferencesystem.cpp.
bool QgsCoordinateReferenceSystem::operator!= | ( | const QgsCoordinateReferenceSystem & | theSrs | ) | const |
Overloaded != operator used to compare to CRS's.
Returns opposite bool value to operator ==
Definition at line 1130 of file qgscoordinatereferencesystem.cpp.
QgsCoordinateReferenceSystem & QgsCoordinateReferenceSystem::operator= | ( | const QgsCoordinateReferenceSystem & | srs | ) |
Assignment operator.
Definition at line 265 of file qgscoordinatereferencesystem.cpp.
bool QgsCoordinateReferenceSystem::operator== | ( | const QgsCoordinateReferenceSystem & | theSrs | ) | const |
Overloaded == operator used to compare to CRS's.
Internally it will delegate to the equals method described below
Definition at line 1124 of file qgscoordinatereferencesystem.cpp.
long QgsCoordinateReferenceSystem::postgisSrid | ( | ) | const |
Get the postgis srid for this srs.
Definition at line 829 of file qgscoordinatereferencesystem.cpp.
QString QgsCoordinateReferenceSystem::projectionAcronym | ( | ) | const |
Get the Projection Acronym.
Definition at line 851 of file qgscoordinatereferencesystem.cpp.
bool QgsCoordinateReferenceSystem::readXML | ( | QDomNode & | theNode | ) |
Restores state from the given Dom node.
theNode | The node from which state will be restored |
Definition at line 1149 of file qgscoordinatereferencesystem.cpp.
|
static |
Returns a list of recently used projections.
Definition at line 2162 of file qgscoordinatereferencesystem.cpp.
bool QgsCoordinateReferenceSystem::saveAsUserCRS | ( | const QString & | name | ) |
Save the proj4-string as a custom CRS.
Copied from QgsCustomProjectionDialog /// Please refactor into SQL handler !!! ///.
Definition at line 1454 of file qgscoordinatereferencesystem.cpp.
|
static |
Sets custom function to force valid CRS QGIS uses implementation in QgisGui::customSrsValidation.
Definition at line 1409 of file qgscoordinatereferencesystem.cpp.
|
static |
Make sure that ESRI WKT import is done properly.
This is required for proper shapefile CRS import when using gdal>= 1.9.
Definition at line 188 of file qgscoordinatereferencesystem.cpp.
void QgsCoordinateReferenceSystem::setValidationHint | ( | const QString & | html | ) |
Set user hint for validation.
Definition at line 1441 of file qgscoordinatereferencesystem.cpp.
long QgsCoordinateReferenceSystem::srsid | ( | ) | const |
Get the SrsId - if possible.
Definition at line 824 of file qgscoordinatereferencesystem.cpp.
|
static |
Update proj.4 parameters in our database from proj.4.
Definition at line 1691 of file qgscoordinatereferencesystem.cpp.
QString QgsCoordinateReferenceSystem::toProj4 | ( | ) | const |
Get the Proj Proj4 string representation of this srs.
If proj and ellps keys are found in the parameters, they will be stripped out and the Projection and ellipsoid acronyms will be overridden with these.
Definition at line 875 of file qgscoordinatereferencesystem.cpp.
QString QgsCoordinateReferenceSystem::toWkt | ( | ) | const |
A helper to get an wkt representation of this srs.
Definition at line 1135 of file qgscoordinatereferencesystem.cpp.
void QgsCoordinateReferenceSystem::validate | ( | ) |
Perform some validation on this CRS.
If the sts doesn't validate the default behaviour settings for layers with unknown CRS will be consulted and acted on accordingly. By hell or high water this method will do its best to make sure that this CRS is valid - even if that involves resorting to a hard coded default of geocs:wgs84.
Definition at line 294 of file qgscoordinatereferencesystem.cpp.
QString QgsCoordinateReferenceSystem::validationHint | ( | ) |
Get user hint for validation.
Definition at line 1446 of file qgscoordinatereferencesystem.cpp.
bool QgsCoordinateReferenceSystem::writeXML | ( | QDomNode & | theNode, |
QDomDocument & | theDoc | ||
) | const |
Stores state to the given Dom node in the given document.
Below is an example of the generated tag.
theNode | The node in which state will be restored |
theDoc | The document in which state will be stored |
Definition at line 1268 of file qgscoordinatereferencesystem.cpp.