QGIS API Documentation  2.11.0-Master
Public Types | Public Slots | Signals | Public Member Functions | Static Public Member Functions | List of all members
QgsCoordinateTransform Class Reference

Class for doing transforms between two map coordinate systems. More...

#include <qgscoordinatetransform.h>

Inheritance diagram for QgsCoordinateTransform:
Inheritance graph
[legend]

Public Types

enum  TransformDirection { ForwardTransform, ReverseTransform }
 Enum used to indicate the direction (forward or inverse) of the transform. More...
 

Public Slots

void initialise ()
 initialise is used to actually create the Transformer instance More...
 
bool readXML (QDomNode &theNode)
 Restores state from the given Dom node. More...
 
bool writeXML (QDomNode &theNode, QDomDocument &theDoc)
 Stores state to the given Dom node in the given document. More...
 

Signals

void invalidTransformInput () const
 Signal when an invalid pj_transform() has occured. More...
 

Public Member Functions

 QgsCoordinateTransform ()
 Default constructor. More...
 
 QgsCoordinateTransform (const QgsCoordinateReferenceSystem &theSource, const QgsCoordinateReferenceSystem &theDest)
 Constructs a QgsCoordinateTransform using QgsCoordinateReferenceSystem objects. More...
 
 QgsCoordinateTransform (long theSourceSrsId, long theDestSrsId)
 Constructs a QgsCoordinateTransform using CRS ID of source and destination CRS. More...
 
 QgsCoordinateTransform (QString theSourceWkt, QString theDestWkt)
 
 QgsCoordinateTransform (long theSourceSrid, QString theDestWkt, QgsCoordinateReferenceSystem::CrsType theSourceCRSType=QgsCoordinateReferenceSystem::PostgisCrsId)
 
 ~QgsCoordinateTransform ()
 destructor More...
 
QgsCoordinateTransformclone () const
 
const QgsCoordinateReferenceSystemdestCRS () const
 
int destinationDatumTransform () const
 
bool isInitialised () const
 
bool isShortCircuited ()
 See if the transform short circuits because src and dest are equivalent. More...
 
void setDestCRS (const QgsCoordinateReferenceSystem &theCRS)
 
void setDestCRSID (long theCRSID)
 Change the destination coordinate system by passing it a qgis srsid A QGIS srsid is a unique key value to an entry on the tbl_srs in the srs.db sqlite database. More...
 
void setDestinationDatumTransform (int dt)
 
void setSourceCrs (const QgsCoordinateReferenceSystem &theCRS)
 
void setSourceDatumTransform (int dt)
 
const QgsCoordinateReferenceSystemsourceCrs () const
 
int sourceDatumTransform () const
 
QgsPoint transform (const QgsPoint &p, TransformDirection direction=ForwardTransform) const
 Transform the point from Source Coordinate System to Destination Coordinate System If the direction is ForwardTransform then coordinates are transformed from layer CS –> map canvas CS, otherwise points are transformed from map canvas CS to layerCS. More...
 
QgsPoint transform (const double x, const double y, TransformDirection direction=ForwardTransform) const
 Transform the point specified by x,y from Source Coordinate System to Destination Coordinate System If the direction is ForwardTransform then coordinates are transformed from layer CS –> map canvas CS, otherwise points are transformed from map canvas CS to layerCS. More...
 
QgsRectangle transform (const QgsRectangle &theRect, TransformDirection direction=ForwardTransform) const
 Transform a QgsRectangle to the dest Coordinate system If the direction is ForwardTransform then coordinates are transformed from layer CS –> map canvas CS, otherwise points are transformed from map canvas CS to layerCS. More...
 
QgsRectangle transformBoundingBox (const QgsRectangle &theRect, TransformDirection direction=ForwardTransform, const bool handle180Crossover=false) const
 Transform a QgsRectangle to the dest Coordinate system If the direction is ForwardTransform then coordinates are transformed from layer CS –> map canvas CS, otherwise points are transformed from map canvas CS to layerCS. More...
 
void transformCoords (const int &numPoint, double *x, double *y, double *z, TransformDirection direction=ForwardTransform) const
 Transform an array of coordinates to a different Coordinate System If the direction is ForwardTransform then coordinates are transformed from layer CS –> map canvas CS, otherwise points are transformed from map canvas CS to layerCS. More...
 
void transformInPlace (double &x, double &y, double &z, TransformDirection direction=ForwardTransform) const
 
void transformInPlace (float &x, float &y, double &z, TransformDirection direction=ForwardTransform) const
 
void transformInPlace (float &x, float &y, float &z, TransformDirection direction=ForwardTransform) const
 
void transformInPlace (QVector< float > &x, QVector< float > &y, QVector< float > &z, TransformDirection direction=ForwardTransform) const
 
void transformInPlace (QVector< double > &x, QVector< double > &y, QVector< double > &z, TransformDirection direction=ForwardTransform) const
 
void transformPolygon (QPolygonF &poly, TransformDirection direction=ForwardTransform) const
 
- Public Member Functions inherited from QObject
 QObject (QObject *parent)
 
 QObject (QObject *parent, const char *name)
 
virtual  ~QObject ()
 
bool blockSignals (bool block)
 
QObjectchild (const char *objName, const char *inheritsClass, bool recursiveSearch) const
 
const QObjectList & children () const
 
const char * className () const
 
bool connect (const QObject *sender, const char *signal, const char *method, Qt::ConnectionType type) const
 
void deleteLater ()
 
void destroyed (QObject *obj)
 
bool disconnect (const QObject *receiver, const char *method)
 
bool disconnect (const char *signal, const QObject *receiver, const char *method)
 
void dumpObjectInfo ()
 
void dumpObjectTree ()
 
QList< QByteArraydynamicPropertyNames () const
 
virtual bool event (QEvent *e)
 
virtual bool eventFilter (QObject *watched, QEvent *event)
 
findChild (const QString &name) const
 
QList< T > findChildren (const QRegExp &regExp) const
 
QList< T > findChildren (const QString &name) const
 
bool inherits (const char *className) const
 
void insertChild (QObject *object)
 
void installEventFilter (QObject *filterObj)
 
bool isA (const char *className) const
 
bool isWidgetType () const
 
void killTimer (int id)
 
virtual const QMetaObjectmetaObject () const
 
void moveToThread (QThread *targetThread)
 
const char * name () const
 
const char * name (const char *defaultName) const
 
QString objectName () const
 
QObjectparent () const
 
QVariant property (const char *name) const
 
void removeChild (QObject *object)
 
void removeEventFilter (QObject *obj)
 
void setName (const char *name)
 
void setObjectName (const QString &name)
 
void setParent (QObject *parent)
 
bool setProperty (const char *name, const QVariant &value)
 
bool signalsBlocked () const
 
int startTimer (int interval)
 
QThreadthread () const
 

Static Public Member Functions

static QList< QList< int > > datumTransformations (const QgsCoordinateReferenceSystem &srcCRS, const QgsCoordinateReferenceSystem &destCRS)
 Returns list of datum transformations for the given src and dest CRS. More...
 
static bool datumTransformCrsInfo (int datumTransform, int &epsgNr, QString &srcProjection, QString &dstProjection, QString &remarks, QString &scope, bool &preferred, bool &deprecated)
 Gets name of source and dest geographical CRS (to show in a tooltip) More...
 
static QString datumTransformString (int datumTransform)
 
- Static Public Member Functions inherited from QObject
bool connect (const QObject *sender, const char *signal, const QObject *receiver, const char *method, Qt::ConnectionType type)
 
bool connect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method, Qt::ConnectionType type)
 
bool disconnect (const QObject *sender, const char *signal, const QObject *receiver, const char *method)
 
bool disconnect (const QObject *sender, const QMetaMethod &signal, const QObject *receiver, const QMetaMethod &method)
 
QString tr (const char *sourceText, const char *disambiguation, int n)
 
QString trUtf8 (const char *sourceText, const char *disambiguation, int n)
 

Additional Inherited Members

- Protected Member Functions inherited from QObject
bool checkConnectArgs (const char *signal, const QObject *object, const char *method)
 
virtual void childEvent (QChildEvent *event)
 
virtual void connectNotify (const char *signal)
 
virtual void customEvent (QEvent *event)
 
virtual void disconnectNotify (const char *signal)
 
int receivers (const char *signal) const
 
QObjectsender () const
 
int senderSignalIndex () const
 
virtual void timerEvent (QTimerEvent *event)
 
- Static Protected Member Functions inherited from QObject
QByteArray normalizeSignalSlot (const char *signalSlot)
 
- Properties inherited from QObject
 objectName
 

Detailed Description

Class for doing transforms between two map coordinate systems.

This class can convert map coordinates to a different coordinate reference system. It is normally associated with a map layer and is used to transform between the layer's coordinate system and the coordinate system of the map canvas, although it can be used in a more general sense to transform coordinates.

All references to source and destination coordinate systems refer to layer and map canvas respectively. All operations are from the perspective of the layer. For example, a forward transformation transforms coordinates from the layers coordinate system to the map canvas.

Definition at line 52 of file qgscoordinatetransform.h.

Constructor & Destructor Documentation

QgsCoordinateTransform::QgsCoordinateTransform ( )

Default constructor.

Make sure you use initialised() manually if you use this one!

Definition at line 40 of file qgscoordinatetransform.cpp.

QgsCoordinateTransform::QgsCoordinateTransform ( const QgsCoordinateReferenceSystem theSource,
const QgsCoordinateReferenceSystem theDest 
)

Constructs a QgsCoordinateTransform using QgsCoordinateReferenceSystem objects.

Parameters
theSourceCRS, typically of the layer's coordinate system
theDestCRS, typically of the map canvas coordinate system

Definition at line 52 of file qgscoordinatetransform.cpp.

QgsCoordinateTransform::QgsCoordinateTransform ( long  theSourceSrsId,
long  theDestSrsId 
)

Constructs a QgsCoordinateTransform using CRS ID of source and destination CRS.

Definition at line 67 of file qgscoordinatetransform.cpp.

QgsCoordinateTransform::QgsCoordinateTransform ( QString  theSourceWkt,
QString  theDestWkt 
)

Constructs a QgsCoordinateTransform using the Well Known Text representation of the layer and map canvas coordinate systems

Parameters
theSourceWktWkt, typically of the layer's coordinate system
theDestWktWkt, typically of the map canvas coordinate system

Definition at line 80 of file qgscoordinatetransform.cpp.

QgsCoordinateTransform::QgsCoordinateTransform ( long  theSourceSrid,
QString  theDestWkt,
QgsCoordinateReferenceSystem::CrsType  theSourceCRSType = QgsCoordinateReferenceSystem::PostgisCrsId 
)

Constructs a QgsCoordinateTransform using a Spatial Reference Id of the layer and map canvas coordinate system as Wkt

Parameters
theSourceSridSpatial Ref Id of the layer's coordinate system
theDestWktWkt of the map canvas coordinate system
theSourceCRSTypeOn of the enum members defined in QgsCoordinateReferenceSystem::CrsType

Definition at line 98 of file qgscoordinatetransform.cpp.

QgsCoordinateTransform::~QgsCoordinateTransform ( )

destructor

Definition at line 119 of file qgscoordinatetransform.cpp.

Member Function Documentation

QgsCoordinateTransform * QgsCoordinateTransform::clone ( ) const

Definition at line 132 of file qgscoordinatetransform.cpp.

QList< QList< int > > QgsCoordinateTransform::datumTransformations ( const QgsCoordinateReferenceSystem srcCRS,
const QgsCoordinateReferenceSystem destCRS 
)
static

Returns list of datum transformations for the given src and dest CRS.

Note
not available in python bindings

Definition at line 807 of file qgscoordinatetransform.cpp.

bool QgsCoordinateTransform::datumTransformCrsInfo ( int  datumTransform,
int &  epsgNr,
QString srcProjection,
QString dstProjection,
QString remarks,
QString scope,
bool &  preferred,
bool &  deprecated 
)
static

Gets name of source and dest geographical CRS (to show in a tooltip)

Returns
epsgNr epsg code of the transformation (or 0 if not in epsg db)

Definition at line 976 of file qgscoordinatetransform.cpp.

QString QgsCoordinateTransform::datumTransformString ( int  datumTransform)
static

Definition at line 922 of file qgscoordinatetransform.cpp.

const QgsCoordinateReferenceSystem& QgsCoordinateTransform::destCRS ( ) const
inline

Get the QgsCoordinateReferenceSystem representation of the map canvas coordinate system

Returns
QgsCoordinateReferenceSystem of the map canvas coordinate system

Definition at line 122 of file qgscoordinatetransform.h.

int QgsCoordinateTransform::destinationDatumTransform ( ) const
inline

Definition at line 228 of file qgscoordinatetransform.h.

void QgsCoordinateTransform::initialise ( )
slot

initialise is used to actually create the Transformer instance

Definition at line 161 of file qgscoordinatetransform.cpp.

void QgsCoordinateTransform::invalidTransformInput ( ) const
signal

Signal when an invalid pj_transform() has occured.

bool QgsCoordinateTransform::isInitialised ( ) const
inline

Flag to indicate whether the coordinate systems have been initialised

Returns
true if initialised, otherwise false

Definition at line 199 of file qgscoordinatetransform.h.

bool QgsCoordinateTransform::isShortCircuited ( )
inline

See if the transform short circuits because src and dest are equivalent.

Returns
bool True if it short circuits

Definition at line 204 of file qgscoordinatetransform.h.

bool QgsCoordinateTransform::readXML ( QDomNode theNode)
slot

Restores state from the given Dom node.

Parameters
theNodeThe node from which state will be restored
Returns
bool True on success, False on failure

Definition at line 740 of file qgscoordinatetransform.cpp.

void QgsCoordinateTransform::setDestCRS ( const QgsCoordinateReferenceSystem theCRS)

Mutator for dest QgsCoordinateReferenceSystem

Parameters
theCRSof the destination coordinate system

Definition at line 146 of file qgscoordinatetransform.cpp.

void QgsCoordinateTransform::setDestCRSID ( long  theCRSID)

Change the destination coordinate system by passing it a qgis srsid A QGIS srsid is a unique key value to an entry on the tbl_srs in the srs.db sqlite database.

Note
This slot will usually be called if the project properties change and a different coordinate system is selected.
This coord transform will be reinitialised when this slot is called to check if short circuiting is needed or not etc.
Parameters
theCRSID- A long representing the srsid of the srs to be used

todo Add some logic here to determine if the srsid is a system or user one

Definition at line 152 of file qgscoordinatetransform.cpp.

void QgsCoordinateTransform::setDestinationDatumTransform ( int  dt)
inline

Definition at line 229 of file qgscoordinatetransform.h.

void QgsCoordinateTransform::setSourceCrs ( const QgsCoordinateReferenceSystem theCRS)

Set the source (layer) QgsCoordinateReferenceSystem

Parameters
theCRSQgsCoordinateReferenceSystem representation of the layer's coordinate system

Definition at line 141 of file qgscoordinatetransform.cpp.

void QgsCoordinateTransform::setSourceDatumTransform ( int  dt)
inline

Definition at line 227 of file qgscoordinatetransform.h.

const QgsCoordinateReferenceSystem& QgsCoordinateTransform::sourceCrs ( ) const
inline

Get the QgsCoordinateReferenceSystem representation of the layer's coordinate system

Returns
QgsCoordinateReferenceSystem of the layer's coordinate system

Definition at line 116 of file qgscoordinatetransform.h.

int QgsCoordinateTransform::sourceDatumTransform ( ) const
inline

Definition at line 226 of file qgscoordinatetransform.h.

QgsPoint QgsCoordinateTransform::transform ( const QgsPoint p,
TransformDirection  direction = ForwardTransform 
) const

Transform the point from Source Coordinate System to Destination Coordinate System If the direction is ForwardTransform then coordinates are transformed from layer CS –> map canvas CS, otherwise points are transformed from map canvas CS to layerCS.

Parameters
pPoint to transform
directionTransformDirection (defaults to ForwardTransform)
Returns
QgsPoint in Destination Coordinate System

Definition at line 278 of file qgscoordinatetransform.cpp.

QgsPoint QgsCoordinateTransform::transform ( const double  x,
const double  y = 0.0,
TransformDirection  direction = ForwardTransform 
) const

Transform the point specified by x,y from Source Coordinate System to Destination Coordinate System If the direction is ForwardTransform then coordinates are transformed from layer CS –> map canvas CS, otherwise points are transformed from map canvas CS to layerCS.

Parameters
xx cordinate of point to transform
yy coordinate of point to transform
directionTransformDirection (defaults to ForwardTransform)
Returns
QgsPoint in Destination Coordinate System

Definition at line 301 of file qgscoordinatetransform.cpp.

QgsRectangle QgsCoordinateTransform::transform ( const QgsRectangle theRect,
TransformDirection  direction = ForwardTransform 
) const

Transform a QgsRectangle to the dest Coordinate system If the direction is ForwardTransform then coordinates are transformed from layer CS –> map canvas CS, otherwise points are transformed from map canvas CS to layerCS.

Parameters
theRectrect to transform
directionTransformDirection (defaults to ForwardTransform)
Returns
QgsRectangle in Destination Coordinate System

Definition at line 315 of file qgscoordinatetransform.cpp.

QgsRectangle QgsCoordinateTransform::transformBoundingBox ( const QgsRectangle theRect,
TransformDirection  direction = ForwardTransform,
const bool  handle180Crossover = false 
) const

Transform a QgsRectangle to the dest Coordinate system If the direction is ForwardTransform then coordinates are transformed from layer CS –> map canvas CS, otherwise points are transformed from map canvas CS to layerCS.

It assumes that rect is a bounding box, and creates a bounding box in the proejcted CS, so that all points in source rectangle is within returned rectangle.

Parameters
theRectrect to transform
directionTransformDirection (defaults to ForwardTransform)
handle180Crossoverset to true if destination crs is geographic and handling of extents crossing the 180 degree longitude line is required
Returns
QgsRectangle in Destination Coordinate System

Definition at line 521 of file qgscoordinatetransform.cpp.

void QgsCoordinateTransform::transformCoords ( const int &  numPoint,
double *  x,
double *  y,
double *  z,
TransformDirection  direction = ForwardTransform 
) const

Transform an array of coordinates to a different Coordinate System If the direction is ForwardTransform then coordinates are transformed from layer CS –> map canvas CS, otherwise points are transformed from map canvas CS to layerCS.

Parameters
numPointnumber of coordinates in arrays
xarray of x coordinates to transform
yarray of y coordinates to transform
zarray of z coordinates to transform
directionTransformDirection (defaults to ForwardTransform)
Returns
QgsRectangle in Destination Coordinate System

Definition at line 628 of file qgscoordinatetransform.cpp.

void QgsCoordinateTransform::transformInPlace ( double &  x,
double &  y,
double &  z,
TransformDirection  direction = ForwardTransform 
) const

Definition at line 351 of file qgscoordinatetransform.cpp.

void QgsCoordinateTransform::transformInPlace ( float &  x,
float &  y,
double &  z,
TransformDirection  direction = ForwardTransform 
) const

Definition at line 372 of file qgscoordinatetransform.cpp.

void QgsCoordinateTransform::transformInPlace ( float &  x,
float &  y,
float &  z,
TransformDirection  direction = ForwardTransform 
) const

Definition at line 381 of file qgscoordinatetransform.cpp.

void QgsCoordinateTransform::transformInPlace ( QVector< float > &  x,
QVector< float > &  y,
QVector< float > &  z,
TransformDirection  direction = ForwardTransform 
) const

Definition at line 476 of file qgscoordinatetransform.cpp.

void QgsCoordinateTransform::transformInPlace ( QVector< double > &  x,
QVector< double > &  y,
QVector< double > &  z,
TransformDirection  direction = ForwardTransform 
) const
Note
not available in python bindings

Definition at line 449 of file qgscoordinatetransform.cpp.

void QgsCoordinateTransform::transformPolygon ( QPolygonF poly,
TransformDirection  direction = ForwardTransform 
) const

Definition at line 408 of file qgscoordinatetransform.cpp.

bool QgsCoordinateTransform::writeXML ( QDomNode theNode,
QDomDocument theDoc 
)
slot

Stores state to the given Dom node in the given document.

Parameters
theNodeThe node in which state will be restored
theDocThe document in which state will be stored
Returns
bool True on success, False on failure

Definition at line 759 of file qgscoordinatetransform.cpp.


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