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#ifndef QGSSPATIALREFSYS_H
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#define QGSSPATIALREFSYS_H
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//gdal and ogr includes
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#include <ogr_spatialref.h>
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#include <cpl_error.h>
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* \class QgsSpatialRefSys
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* \brief Class for storing a spatial reference system (SRS)
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class QgsSpatialRefSys
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//! Default constructor
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* Constructs a SRS object from a WKT string
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* @param theWkt A String containing a valid Wkt def
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explicit QgsSpatialRefSys(QString theWkt);
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* Constructs a SRS object from the following component parts
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* @param long theSrsId The internal sqlite3 srs.db primary key for this srs
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* @param QString the Description A textual description of the srs.
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* @param QString theProjectionAcronym The official proj4 acronym for the projection family
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* @param QString theEllipsoidAcronym The official proj4 acronym for the ellipoid
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* @param QString theProj4String Proj4 format specifies (excluding proj and ellips) that define this srs.
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* @param bool theGeoFlag Whether this is a geographic or projected coordinate system
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* @param long theSRID If available, the Postgis spatial_ref_sys identifier for this srs (defaults to 0)
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* @param long theEpsg If available the ESPG identifier for this srs (defaults to 0)
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* @note THIS CTOR WILL PROABBLY BE REMOVED!!!!!!!!!!!!!!!!
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QgsSpatialRefSys(long theSrsId,
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QString theDescription,
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QString theProjectionAcronym,
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QString theEllipsoidAcronym,
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QString theProj4String,
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enum SRS_TYPE {QGIS_SRSID,POSTGIS_SRID, EPSG};
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/*! Use this constructor when you want to create a SRS object using
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* a postgis SRID, an EPSG id or a QGIS SRS_ID.
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* @param theId The ID no valid for the chosen coordinate system id type
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* @param theType One of the types described in QgsSpatialRefSys::SRS_TYPE
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QgsSpatialRefSys(const long theId, SRS_TYPE theType=POSTGIS_SRID);
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// Assignment operator
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QgsSpatialRefSys& operator=(const QgsSpatialRefSys& srs);
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// Misc helper functions -----------------------
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void createFromId(const long theId, SRS_TYPE theType=POSTGIS_SRID);
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* \brief Set up this SRS from the given OGC CRS
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* Sets this SRS to the given OGC WMS-format Coordinate Reference Systems.
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* \note This function only deals with EPSG labels only at this time.
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* \retval FALSE if not given an EPSG label
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bool createFromOgcWmsCrs(QString theCrs);
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/*! Set up this srs by fetching the appropriate information from the
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* sqlite backend. First the system level read only srs.db will be checked
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* and then the users ~/.qgis/qgis.db database will be checked for a match.
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* @note Any members will be overwritten during this process.
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* @param theSrid The postgis SRID for the desired spatial reference system.
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bool createFromSrid(const long theSrid);
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/*! Set up this srs using a WKT spatial ref sys definition.
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* The wkt will be converted to a proj4 string using OGR helper
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* functions. After this the srs databasses will be searched for matches.
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* First the system level read only srs.db will be checked
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* and then the users ~/.qgis/qgis.db database will be checked for a match.
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* @note Any members will be overwritten during this process.
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* @note SRID and EPSG may be blank if no match can be found on srs db.
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* @param theWkt The WKT for the desired spatial reference system.
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* @return bool TRUE if sucess else false
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bool createFromWkt(const QString theWkt);
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/*! Set up this srs by fetching the appropriate information from the
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* sqlite backend. First the system level read only srs.db will be checked
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* and then the users ~/.qgis/qgis.db database will be checked for a match.
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* @note Any members will be overwritten during this process.
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* @param theEpsg The EPSG for the desired spatial reference system.
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* @return bool TRUE if sucess else false
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bool createFromEpsg(const long theEpsg);
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/*! Set up this srs by fetching the appropriate information from the
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* sqlite backend. If the srsid is < 100000, only the system srs.db
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* will be checked. If the srsid > 100000 the srs will be retrieved from
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* the ~/.qgis/qgis.db
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* @note Any members will be overwritten during this process.
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* @param theSrsId The QGIS SrsId for the desired spatial reference system.
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* @return bool TRUE if sucess else false
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bool createFromSrsId (const long theSrsId);
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/*! Set up this srs by passing it a proj4 style formatted string.
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* The string will be parsed and the projection and ellipsoid
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* members set and the remainder of the proj4 string will be stored
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* in the parameters member. The reason for this is so that we
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* can easily present the user with 'natural language' representation
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* of the projection and ellipsoid by looking them up in the srs.bs sqlite
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* database. Also having the ellpse and proj elements stripped out
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* is hepful to speed up globbing queries (see below).
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* We try to match the proj string to and srsid using the following logic:
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* - perform a whole text search on srs name (if not null). The srs name will
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* have been set if this method has been delegated to from createFromWkt.
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* - if the above does not match perform a whole text search on proj4 string (if not null)
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* - if none of the above match convert the proj4 string to an OGR SRS
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* then check if its a geocs or a proj cs (using ogr isGeographic)
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* then sequentially walk through the database (first users qgis.db srs tbl then
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* system srs.db tbl), converting each entry into an ogr srs and using isSame
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* or isSameGeocs (essentially calling the == overloaded operator). We'll try to
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* be smart about this and first parse out the proj and ellpse strings and only
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* check for a match in entities that have the same ellps and proj entries so
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* that it doesnt munch yer cpu so much.
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* @note If the srs was not matched, we will create a new entry on the users tbl_srs
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* @param theProjString A proj4 format string
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* @return bool TRUE if sucess else false
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bool createFromProj4 (const QString theProjString);
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/*! Find out whether this SRS is correctly initialised and useable */
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bool isValid() const;
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/*! Perform some validation on this SRS. If the sts doesnt validate the
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* default behaviour settings for layers with unknown SRS will be
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* consulted and acted on accordingly. By hell or high water this
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* method will do its best to make sure that this SRS is valid - even
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* if that involves resorting to a hard coded default of geocs:wgs84.
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* @note It is not usually neccessary to use this function, unless you
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* are trying to force theis srs to be valid.
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/*! This is a globbing function to try to find a record in the database
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* that matches a SRS defined only by a proj4string. The goal is to
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* learn what the tbl_srs.srs_id value is for the SRS. Internally
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* the source SRS is converted to and OGR srs object using the proj4string
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* and then every record in the database that matches projection and ellipsoid
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* will be converted to an OGR srs in turn and compared to the source SRS.
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* There are some gotchas with using ogr isSame() srs comparison, but
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* its more effective than using straight string comparison of proj4params.
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* @note The ellipsoid and projection acronyms must be set as well as the proj4string!
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* @return lomg the SrsId of the matched SRS
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long findMatchingProj();
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/*! A string based associative array used for passing records around */
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typedef QMap<QString, QString> RecordMap;
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/*! Get a record from the srs.db or qgis.db backends, given an sql statment.
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* @note only handles queries that return a single record.
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* @note it will first try the system srs.db then the users qgis.db!
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* @param QString The sql query to execute
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* @return QMap An associative array of field name <-> value pairs
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RecordMap getRecord(QString theSql);
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/*! Overloaded == operator used to compare to SRS's.
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* Internally it will delegate to the equals method described below
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bool operator==(const QgsSpatialRefSys &theSrs);
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/*! Overloaded == operator used to compare to SRS's.
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* Internally it will use OGR isSameSRS() or isSameGeoSRS() methods as appropriate.
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* Additionally logic may also be applied if the result from the OGR methods
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bool equals(QString theProj4String);
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/*! A helper to get an ogr representation of this srs
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* @return OGRSpatialReference
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OGRSpatialReference toOgrSrs();
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/*! Restores state from the given DOM node.
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* @param theNode The node from which state will be restored
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* @return bool True on success, False on failure
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bool readXML( QDomNode & theNode );
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/*! Stores state to the given DOM node in the given document.
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* Below is an example of the generated tag.
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* <proj4>+proj=longlat +ellps=WGS84 +datum=WGS84 +no_defs </proj4>
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* <srsid>2585</srsid>
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* <description>WGS 84</description>
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* <projectionacronym>longlat</projectionacronym>
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* <ellipsoidacronym>WGS84</ellipsoidacronym>
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* @param theNode The node in which state will be restored
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* @param theDom The document in which state will be stored
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* @return bool True on success, False on failure
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bool writeXML( QDomNode & theNode, QDomDocument & theDoc );
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/** A static helper function to find out the proj4 string for a srsid
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* @param int theSrsId The srsid used for the lookup
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* @return QString The proj4 string
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static QString getProj4FromSrsId(const int theSrsId);
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// Accessors -----------------------------------
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/*! Get the SrsId - if possible
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* @return long theSrsId The internal sqlite3 srs.db primary key for this srs
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/*! Get the Postgis SRID - if possible.
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* @return long theSRID The internal postgis SRID for this SRS
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/*! Get the Description
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* @return QString the Description A textual description of the srs.
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* @note A zero length string will be returned if the description is uninitialised
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QString description () const;
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/*! Get the Projection Acronym
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* @return QString theProjectionAcronym The official proj4 acronym for the projection family
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* @note A zero length string will be returned if the projectionAcronym is uninitialised
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QString projectionAcronym() const;
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/*! Get the Ellipsoid Acronym
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* @return QString theEllipsoidAcronym The official proj4 acronym for the ellipoid
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* @note A zero length string will be returned if the ellipsoidAcronym is uninitialised
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QString ellipsoidAcronym () const;
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/** Get the Proj Proj4String. If proj and ellps keys are found in the parameters,
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* they will be stripped out and the Projection and ellipsoid acronyms will be
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* overridden with these.
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* @return QString theProj4String Proj4 format specifies that define this srs.
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* @note A zero length string will be returned if the proj4String is uninitialised
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QString proj4String() const;
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/*! Get this Geographic? flag
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* @return bool theGeoFlag Whether this is a geographic or projected coordinate system
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bool geographicFlag () const;
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/*! Get the units that the projection is in
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* @return QGis::units that gives the units for the coordinate system
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QGis::units mapUnits() const;
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/*! Set the postgis srid for this srs
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* @return long theSRID the Postgis spatial_ref_sys identifier for this srs (defaults to 0)
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long postgisSrid () const;
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/*! Set the EPSG identifier for this srs
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* @return long theEpsg the ESPG identifier for this srs (defaults to 0)
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// Mutators -----------------------------------
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/*! Set the QGIS SrsId
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* @param long theSrsId The internal sqlite3 srs.db primary key for this srs
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void setSrsId(long theSrsId);
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/*! Set the postgis srid
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* @param long theSrsId The postgis spatial_ref_sys key for this srs
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void setSrid(long theSrid);
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/*! Set the Description
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* @param QString the Description A textual description of the srs.
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void setDescription (QString theDescription);
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/* Set the Proj Proj4String.
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* @param QString theProj4String Proj4 format specifies (excluding proj and ellips) that define this srs.
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void setProj4String (QString theProj4String);
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/*! Set this Geographic? flag
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* @param bool theGeoFlag Whether this is a geographic or projected coordinate system
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void setGeographicFlag (bool theGeoFlag);
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/*! Set the EPSG identifier for this srs
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* @param long theEpsg the ESPG identifier for this srs (defaults to 0)
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void setEpsg (long theEpsg);
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/*! Set the projection acronym
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* @param QString the acronym (must be a valid proj4 projection acronym)
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void setProjectionAcronym(QString theProjectionAcronym);
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/*! Set the ellipsoid acronym
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* @param QString the acronym (must be a valid proj4 ellipsoid acronym)
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void setEllipsoidAcronym(QString theEllipsoidAcronym);
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// Open SQLite db and show message if ccannot be opened
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// returns the same code as sqlite3_open
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static int openDb ( QString path, sqlite3 **db );
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//!The internal sqlite3 srs.db primary key for this srs
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//!A textual description of the srs.
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QString mDescription;
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//!The official proj4 acronym for the projection family
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QString mProjectionAcronym ;
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//!The official proj4 acronym for the ellipoid
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QString mEllipsoidAcronym;
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//!Proj4 format specifies (excluding proj and ellips) that define this srs.
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QString mProj4String ;
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//!Whether this is a geographic or projected coordinate system
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QGis::units mMapUnits;
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//!If available, the Postgis spatial_ref_sys identifier for this srs (defaults to 0)
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//!If available the ESPG identifier for this srs (defaults to 0)
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//! Wehter this srs is properly defined and valid
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//! Work out the projection units and set the appropriate local variable
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//! Output stream operator
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inline std::ostream& operator << (std::ostream& os, const QgsSpatialRefSys &r)
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QString mySummary ("\n\tSpatial Reference System:");
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mySummary += "\n\t\tDescription : ";
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if (!r.description().isNull())
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mySummary += r.description();
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mySummary += "Undefined" ;
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mySummary += "\n\t\tProjection : " ;
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if (!r.projectionAcronym().isNull())
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mySummary += r.projectionAcronym();
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mySummary += "Undefined" ;
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mySummary += "\n\t\tEllipsoid : ";
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if (!r.ellipsoidAcronym().isNull())
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mySummary += r.ellipsoidAcronym();
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mySummary += "Undefined" ;
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mySummary += "\n\t\tProj4String : " ;
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if (!r.proj4String().isNull())
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mySummary += r.proj4String();
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mySummary += "Undefined" ;
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// Using streams we need to use local 8 Bit
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return os << mySummary.toLocal8Bit().data() << std::endl;
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//! Input stream operator
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inline std::istream& operator>> (std::istream& str, QgsSpatialRefSys& r)
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//std::cout << "FIXME FIXME" << __FILE__ << ":" << __LINE__ << std::endl;
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//QString srs = s.c_str();
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// split the string into the parts to created the object
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//QStringList parts = QStringList::split(QRegExp("\t"),srs);
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// r.setSrid(parts[0]);
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// r.setAuthName(parts[1]);
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// r.setAuthSrid(parts[2]);
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// r.setSrText(parts[3]);
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// r.setProjText(parts[4]);
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// r.setName(parts[5]);
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#endif // QGSSPATIALREFSYS_H
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src/gui/qgsspatialrefsys.h
