Geometry collection. More...

#include <qgsgeometrycollection.h>

Inheritance diagram for QgsGeometryCollection:

[legend]

Public Member Functions
	QgsGeometryCollection ()

	QgsGeometryCollection (const QgsGeometryCollection &c)

	~QgsGeometryCollection () override

virtual bool	addGeometry (QgsAbstractGeometry *g)
	Adds a geometry and takes ownership. Returns `true` in case of success. More...

bool	addMValue (double mValue=0) override
	Adds a measure to the geometry, initialized to a preset value. More...

bool	addZValue (double zValue=0) override
	Adds a z-dimension to the geometry, initialized to a preset value. More...

void	adjacentVertices (QgsVertexId vertex, QgsVertexId &previousVertex, QgsVertexId &nextVertex) const override
	Returns the vertices adjacent to a specified vertex within a geometry. More...

double	area () const override
	Returns the planar, 2-dimensional area of the geometry. More...

QDomElement	asGml2 (QDomDocument &doc, int precision=17, const QString &ns="gml", QgsAbstractGeometry::AxisOrder axisOrder=QgsAbstractGeometry::AxisOrder::XY) const override
	Returns a GML2 representation of the geometry. More...

QDomElement	asGml3 (QDomDocument &doc, int precision=17, const QString &ns="gml", QgsAbstractGeometry::AxisOrder axisOrder=QgsAbstractGeometry::AxisOrder::XY) const override
	Returns a GML3 representation of the geometry. More...

json	asJsonObject (int precision=17) const override
	Returns a json object representation of the geometry. More...

QString	asKml (int precision=17) const override
	Returns a KML representation of the geometry. More...

QByteArray	asWkb (QgsAbstractGeometry::WkbFlags flags=QgsAbstractGeometry::WkbFlags()) const override

QString	asWkt (int precision=17) const override
	Returns a WKT representation of the geometry. More...

QgsAbstractGeometry *	boundary () const override
	Returns the closure of the combinatorial boundary of the geometry (ie the topological boundary of the geometry). More...

QgsRectangle	boundingBox () const override
	Returns the minimal bounding box for the geometry. More...

const QgsGeometryCollection *	cast (const QgsAbstractGeometry *geom) const
	Cast the geom to a QgsGeometryCollection. More...

void	clear () override
	Clears the geometry, ie reset it to a null geometry. More...

QgsGeometryCollection *	clone () const override
	Clones the geometry by performing a deep copy. More...

double	closestSegment (const QgsPoint &pt, QgsPoint &segmentPt, QgsVertexId &vertexAfter, int leftOf=nullptr, double epsilon=4 std::numeric_limits< double >::epsilon()) const override
	Searches for the closest segment of the geometry to a given point. More...

QgsCoordinateSequence	coordinateSequence () const override
	Retrieves the sequence of geometries, rings and nodes. More...

QgsGeometryCollection *	createEmptyWithSameType () const override
	Creates a new geometry with the same class and same WKB type as the original and transfers ownership. More...

bool	deleteVertex (QgsVertexId position) override
	Deletes a vertex within the geometry. More...

int	dimension () const override
	Returns the inherent dimension of the geometry. More...

void	draw (QPainter &p) const override
	Draws the geometry using the specified QPainter. More...

bool	dropMValue () override
	Drops any measure values which exist in the geometry. More...

bool	dropZValue () override
	Drops any z-dimensions which exist in the geometry. More...

void	filterVertices (const std::function< bool(const QgsPoint &) > &filter) override
	Filters the vertices from the geometry in place, removing any which do not return `true` for the filter function check. More...

bool	fromWkb (QgsConstWkbPtr &wkb) override
	Sets the geometry from a WKB string. More...

bool	fromWkt (const QString &wkt) override
	Sets the geometry from a WKT string. More...

QgsAbstractGeometry *	geometryN (int n)
	Returns a geometry from within the collection. More...

const QgsAbstractGeometry *	geometryN (int n) const
	Returns a const reference to a geometry from within the collection. More...

QString	geometryType () const override
	Returns a unique string representing the geometry type. More...

bool	hasCurvedSegments () const override
	Returns `true` if the geometry contains curved segments. More...

virtual bool	insertGeometry (QgsAbstractGeometry *g, int index)
	Inserts a geometry before a specified index and takes ownership. More...

bool	insertVertex (QgsVertexId position, const QgsPoint &vertex) override
	Inserts a vertex into the geometry. More...

bool	isEmpty () const override
	Returns `true` if the geometry is empty. More...

bool	isValid (QString &error, int flags=0) const override
	Checks validity of the geometry, and returns `true` if the geometry is valid. More...

double	length () const override
	Returns the planar, 2-dimensional length of the geometry. More...

bool	moveVertex (QgsVertexId position, const QgsPoint &newPos) override
	Moves a vertex within the geometry. More...

int	nCoordinates () const override
	Returns the number of nodes contained in the geometry. More...

bool	nextVertex (QgsVertexId &id, QgsPoint &vertex) const override
	Returns next vertex id and coordinates. More...

int	numGeometries () const
	Returns the number of geometries within the collection. More...

bool	operator!= (const QgsAbstractGeometry &other) const override

QgsGeometryCollection &	operator= (const QgsGeometryCollection &c)

bool	operator== (const QgsAbstractGeometry &other) const override

int	partCount () const override
	Returns count of parts contained in the geometry. More...

double	perimeter () const override
	Returns the planar, 2-dimensional perimeter of the geometry. More...

bool	removeDuplicateNodes (double epsilon=4 *std::numeric_limits< double >::epsilon(), bool useZValues=false) override
	Removes duplicate nodes from the geometry, wherever removing the nodes does not result in a degenerate geometry. More...

virtual bool	removeGeometry (int nr)
	Removes a geometry from the collection. More...

void	reserve (int size)
	Attempts to allocate memory for at least size geometries. More...

int	ringCount (int part=0) const override
	Returns the number of rings of which this geometry is built. More...

QgsAbstractGeometry *	segmentize (double tolerance=M_PI_2/90, SegmentationToleranceType toleranceType=MaximumAngle) const override
	Returns a geometry without curves. More...

double	segmentLength (QgsVertexId startVertex) const override
	Returns the length of the segment of the geometry which begins at startVertex. More...

QgsGeometryCollection *	snappedToGrid (double hSpacing, double vSpacing, double dSpacing=0, double mSpacing=0) const override
	Makes a new geometry with all the points or vertices snapped to the closest point of the grid. More...

void	swapXy () override
	Swaps the x and y coordinates from the geometry. More...

QgsGeometryCollection *	toCurveType () const override
	Returns the geometry converted to the more generic curve type. More...

void	transform (const QgsCoordinateTransform &ct, QgsCoordinateTransform::TransformDirection d=QgsCoordinateTransform::ForwardTransform, bool transformZ=false) override SIP_THROW(QgsCsException)
	Transforms the geometry using a coordinate transform. More...

void	transform (const QTransform &t, double zTranslate=0.0, double zScale=1.0, double mTranslate=0.0, double mScale=1.0) override
	Transforms the x and y components of the geometry using a QTransform object t. More...

void	transformVertices (const std::function< QgsPoint(const QgsPoint &) > &transform) override
	Transforms the vertices from the geometry in place, applying the transform function to every vertex. More...

double	vertexAngle (QgsVertexId vertex) const override
	Returns approximate angle at a vertex. More...

QgsPoint	vertexAt (QgsVertexId id) const override
	Returns the point corresponding to a specified vertex id. More...

int	vertexCount (int part=0, int ring=0) const override
	Returns the number of vertices of which this geometry is built. More...

int	vertexNumberFromVertexId (QgsVertexId id) const override
	Returns the vertex number corresponding to a vertex id. More...

Public Member Functions inherited from QgsAbstractGeometry
	QgsAbstractGeometry ()=default
	Constructor for QgsAbstractGeometry. More...

	QgsAbstractGeometry (const QgsAbstractGeometry &geom)

virtual	~QgsAbstractGeometry ()=default

QString	asJson (int precision=17)
	Returns a GeoJSON representation of the geometry as a QString. More...

virtual QByteArray	asWkb (WkbFlags flags=QgsAbstractGeometry::WkbFlags()) const =0
	Returns a WKB representation of the geometry. More...

virtual QgsPoint	centroid () const
	Returns the centroid of the geometry. More...

const_part_iterator	const_parts_begin () const
	Returns STL-style iterator pointing to the const first part of the geometry. More...

const_part_iterator	const_parts_end () const
	Returns STL-style iterator pointing to the imaginary const part after the last part of the geometry. More...

virtual bool	convertTo (QgsWkbTypes::Type type)
	Converts the geometry to a specified type. More...

bool	is3D () const
	Returns `true` if the geometry is 3D and contains a z-value. More...

bool	isMeasure () const
	Returns `true` if the geometry contains m values. More...

QgsAbstractGeometry &	operator= (const QgsAbstractGeometry &geom)

QgsGeometryPartIterator	parts ()
	Returns Java-style iterator for traversal of parts of the geometry. More...

QgsGeometryConstPartIterator	parts () const
	Returns Java-style iterator for traversal of parts of the geometry. More...

part_iterator	parts_begin ()
	Returns STL-style iterator pointing to the first part of the geometry. More...

part_iterator	parts_end ()
	Returns STL-style iterator pointing to the imaginary part after the last part of the geometry. More...

QgsVertexIterator	vertices () const
	Returns a read-only, Java-style iterator for traversal of vertices of all the geometry, including all geometry parts and rings. More...

vertex_iterator	vertices_begin () const
	Returns STL-style iterator pointing to the first vertex of the geometry. More...

vertex_iterator	vertices_end () const
	Returns STL-style iterator pointing to the imaginary vertex after the last vertex of the geometry. More...

QgsWkbTypes::Type	wkbType () const
	Returns the WKB type of the geometry. More...

QString	wktTypeStr () const
	Returns the WKT type string of the geometry. More...

Protected Member Functions
QgsRectangle	calculateBoundingBox () const override
	Default calculator for the minimal bounding box for the geometry. More...

int	childCount () const override
	Returns number of child geometries (for geometries with child geometries) or child points (for geometries without child geometries - i.e. More...

QgsAbstractGeometry *	childGeometry (int index) const override
	Returns pointer to child geometry (for geometries with child geometries - i.e. More...

void	clearCache () const override
	Clears any cached parameters associated with the geometry, e.g., bounding boxes. More...

bool	fromCollectionWkt (const QString &wkt, const QVector< QgsAbstractGeometry * > &subtypes, const QString &defaultChildWkbType=QString())
	Reads a collection from a WKT string. More...

virtual bool	wktOmitChildType () const
	Returns whether child type names are omitted from Wkt representations of the collection. More...

Protected Member Functions inherited from QgsAbstractGeometry
virtual QgsPoint	childPoint (int index) const
	Returns point at index (for geometries without child geometries - i.e. More...

virtual bool	hasChildGeometries () const
	Returns whether the geometry has any child geometries (`false` for point / curve, `true` otherwise) More...

void	setZMTypeFromSubGeometry (const QgsAbstractGeometry *subggeom, QgsWkbTypes::Type baseGeomType)
	Updates the geometry type based on whether sub geometries contain z or m values. More...

Protected Attributes
QVector< QgsAbstractGeometry * >	mGeometries

Protected Attributes inherited from QgsAbstractGeometry
QgsWkbTypes::Type	mWkbType = QgsWkbTypes::Unknown

Additional Inherited Members
Public Types inherited from QgsAbstractGeometry
enum	AxisOrder { XY = 0, YX }
	Axis order for GML generation. More...

enum	SegmentationToleranceType { MaximumAngle = 0, MaximumDifference }
	Segmentation tolerance as maximum angle or maximum difference between approximation and circle. More...

enum	WkbFlag { FlagExportTrianglesAsPolygons = 1 << 0 }
	WKB export flags. More...

Detailed Description

Geometry collection.

Since: QGIS 2.10

Definition at line 35 of file qgsgeometrycollection.h.

Constructor & Destructor Documentation

◆ QgsGeometryCollection() [1/2]

QgsGeometryCollection::QgsGeometryCollection ( )

Definition at line 34 of file qgsgeometrycollection.cpp.

◆ QgsGeometryCollection() [2/2]

QgsGeometryCollection::QgsGeometryCollection ( const QgsGeometryCollection & c )

Definition at line 39 of file qgsgeometrycollection.cpp.

◆ ~QgsGeometryCollection()

QgsGeometryCollection::~QgsGeometryCollection ( )

override

Definition at line 69 of file qgsgeometrycollection.cpp.

Member Function Documentation

◆ addGeometry()

bool QgsGeometryCollection::addGeometry ( QgsAbstractGeometry * g )

virtual

Adds a geometry and takes ownership. Returns true in case of success.

Reimplemented in QgsMultiPoint, QgsMultiCurve, QgsMultiLineString, QgsMultiSurface, and QgsMultiPolygon.

Definition at line 226 of file qgsgeometrycollection.cpp.

◆ addMValue()

bool QgsGeometryCollection::addMValue ( double mValue = 0 )

overridevirtual

Adds a measure to the geometry, initialized to a preset value.

Parameters

mValue initial m-value for all nodes

Returns: true on success

See also: dropMValue(); addZValue()

Since: QGIS 2.12

Implements QgsAbstractGeometry.

Definition at line 867 of file qgsgeometrycollection.cpp.

◆ addZValue()

bool QgsGeometryCollection::addZValue ( double zValue = 0 )

overridevirtual

Adds a z-dimension to the geometry, initialized to a preset value.

Parameters

zValue initial z-value for all nodes

Returns: true on success

See also: dropZValue(); addMValue()

Since: QGIS 2.12

Implements QgsAbstractGeometry.

Definition at line 852 of file qgsgeometrycollection.cpp.

◆ adjacentVertices()

void QgsGeometryCollection::adjacentVertices	(	QgsVertexId	vertex,
		QgsVertexId &	previousVertex,
		QgsVertexId &	nextVertex
	)		const

overridevirtual

Returns the vertices adjacent to a specified vertex within a geometry.

Since: QGIS 3.0

Implements QgsAbstractGeometry.

Definition at line 164 of file qgsgeometrycollection.cpp.

◆ area()

double QgsGeometryCollection::area ( ) const

overridevirtual

Returns the planar, 2-dimensional area of the geometry.

Warning: QgsAbstractGeometry objects are inherently Cartesian/planar geometries, and the area returned by this method is calculated using strictly Cartesian mathematics. In contrast, the QgsDistanceArea class exposes methods for calculating the areas of geometries using geodesic calculations which account for the curvature of the Earth (or any other celestial body).

See also: length(); perimeter()

Reimplemented from QgsAbstractGeometry.

Definition at line 654 of file qgsgeometrycollection.cpp.

◆ asGml2()

QDomElement QgsGeometryCollection::asGml2	(	QDomDocument &	doc,
		int	precision = `17`,
		const QString &	ns = `"gml"`,
		QgsAbstractGeometry::AxisOrder	axisOrder = `QgsAbstractGeometry::AxisOrder::XY`
	)		const

overridevirtual

Returns a GML2 representation of the geometry.

Parameters

doc	DOM document
precision	number of decimal places for coordinates
ns	XML namespace
axisOrder	Axis order for generated GML

See also: asWkb(); asWkt(); asGml3(); asJson()

Implements QgsAbstractGeometry.

Reimplemented in QgsMultiPoint, QgsMultiCurve, QgsMultiLineString, QgsMultiSurface, and QgsMultiPolygon.

Definition at line 414 of file qgsgeometrycollection.cpp.

◆ asGml3()

QDomElement QgsGeometryCollection::asGml3	(	QDomDocument &	doc,
		int	precision = `17`,
		const QString &	ns = `"gml"`,
		QgsAbstractGeometry::AxisOrder	axisOrder = `QgsAbstractGeometry::AxisOrder::XY`
	)		const

overridevirtual

Returns a GML3 representation of the geometry.

Parameters

doc	DOM document
precision	number of decimal places for coordinates
ns	XML namespace
axisOrder	Axis order for generated GML

See also: asWkb(); asWkt(); asGml2(); asJson()

Implements QgsAbstractGeometry.

Reimplemented in QgsMultiPoint, QgsMultiCurve, QgsMultiLineString, QgsMultiSurface, and QgsMultiPolygon.

Definition at line 426 of file qgsgeometrycollection.cpp.

◆ asJsonObject()

json QgsGeometryCollection::asJsonObject ( int precision = 17 ) const

overridevirtual

Returns a json object representation of the geometry.

See also: asWkb(); asWkt(); asGml2(); asGml3(); asJson()

Note: not available in Python bindings

Since: QGIS 3.10

Reimplemented from QgsAbstractGeometry.

Reimplemented in QgsMultiPoint, QgsMultiCurve, QgsMultiLineString, QgsMultiSurface, and QgsMultiPolygon.

Definition at line 438 of file qgsgeometrycollection.cpp.

◆ asKml()

QString QgsGeometryCollection::asKml ( int precision = 17 ) const

overridevirtual

Returns a KML representation of the geometry.

Since: QGIS 3.12

Implements QgsAbstractGeometry.

Definition at line 452 of file qgsgeometrycollection.cpp.

◆ asWkb()

QByteArray QgsGeometryCollection::asWkb ( QgsAbstractGeometry::WkbFlags flags = QgsAbstractGeometry::WkbFlags() ) const

override

Definition at line 360 of file qgsgeometrycollection.cpp.

◆ asWkt()

QString QgsGeometryCollection::asWkt ( int precision = 17 ) const

overridevirtual

Returns a WKT representation of the geometry.

Parameters

precision number of decimal places for coordinates

See also: asWkb(); asGml2(); asGml3(); asJson()

Implements QgsAbstractGeometry.

Definition at line 387 of file qgsgeometrycollection.cpp.

◆ boundary()

QgsAbstractGeometry * QgsGeometryCollection::boundary ( ) const

overridevirtual

Returns the closure of the combinatorial boundary of the geometry (ie the topological boundary of the geometry).

For instance, a polygon geometry will have a boundary consisting of the linestrings for each ring in the polygon.

Returns: boundary for geometry. May be nullptr for some geometry types.

Since: QGIS 3.0

Implements QgsAbstractGeometry.

Reimplemented in QgsMultiCurve, QgsMultiPolygon, QgsMultiPoint, and QgsMultiSurface.

Definition at line 159 of file qgsgeometrycollection.cpp.

◆ boundingBox()

QgsRectangle QgsGeometryCollection::boundingBox ( ) const

overridevirtual

Returns the minimal bounding box for the geometry.

Implements QgsAbstractGeometry.

Definition at line 465 of file qgsgeometrycollection.cpp.

◆ calculateBoundingBox()

QgsRectangle QgsGeometryCollection::calculateBoundingBox ( ) const

overrideprotectedvirtual

Default calculator for the minimal bounding box for the geometry.

Derived classes should override this method if a more efficient bounding box calculation is available.

Reimplemented from QgsAbstractGeometry.

Definition at line 474 of file qgsgeometrycollection.cpp.

◆ cast()

const QgsGeometryCollection* QgsGeometryCollection::cast ( const QgsAbstractGeometry * geom ) const

inline

Cast the geom to a QgsGeometryCollection.

Should be used by qgsgeometry_cast<QgsGeometryCollection *>( geometry ).

Note: Not available in Python. Objects will be automatically be converted to the appropriate target type.

Since: QGIS 3.0

Definition at line 240 of file qgsgeometrycollection.h.

◆ childCount()

int QgsGeometryCollection::childCount ( ) const

overrideprotectedvirtual

Returns number of child geometries (for geometries with child geometries) or child points (for geometries without child geometries - i.e.

curve / point)

Note: used for vertex_iterator implementation

Since: QGIS 3.0

Reimplemented from QgsAbstractGeometry.

Definition at line 957 of file qgsgeometrycollection.cpp.

◆ childGeometry()

QgsAbstractGeometry * QgsGeometryCollection::childGeometry ( int index ) const

overrideprotectedvirtual

Returns pointer to child geometry (for geometries with child geometries - i.e.

geom. collection / polygon)

Note: used for vertex_iterator implementation

Since: QGIS 3.0

Reimplemented from QgsAbstractGeometry.

Definition at line 962 of file qgsgeometrycollection.cpp.

◆ clear()

void QgsGeometryCollection::clear ( )

overridevirtual

Clears the geometry, ie reset it to a null geometry.

Implements QgsAbstractGeometry.

Reimplemented in QgsMultiPoint, QgsMultiLineString, QgsMultiCurve, QgsMultiPolygon, and QgsMultiSurface.

Definition at line 123 of file qgsgeometrycollection.cpp.

◆ clearCache()

void QgsGeometryCollection::clearCache ( ) const

overrideprotectedvirtual

Clears any cached parameters associated with the geometry, e.g., bounding boxes.

Reimplemented from QgsAbstractGeometry.

Definition at line 510 of file qgsgeometrycollection.cpp.

◆ clone()

QgsGeometryCollection * QgsGeometryCollection::clone ( ) const

overridevirtual

Clones the geometry by performing a deep copy.

Implements QgsAbstractGeometry.

Reimplemented in QgsMultiLineString, QgsMultiPoint, QgsMultiPolygon, QgsMultiSurface, and QgsMultiCurve.

Definition at line 118 of file qgsgeometrycollection.cpp.

◆ closestSegment()

double QgsGeometryCollection::closestSegment	(	const QgsPoint &	pt,
		QgsPoint &	segmentPt,
		QgsVertexId &	vertexAfter,
		int *	leftOf = `nullptr`,
		double	epsilon = `4 *std::numeric_limits< double >::epsilon()`
	)		const

overridevirtual

Searches for the closest segment of the geometry to a given point.

Parameters

pt	specifies the point to find closest segment to
segmentPt	storage for the closest point within the geometry
vertexAfter	storage for the ID of the vertex at the end of the closest segment
leftOf	indicates whether the point lies on the left side of the geometry (-1 if point is to the left of the geometry, +1 if the point is to the right of the geometry, or 0 for cases where left/right could not be determined, e.g. point exactly on a line) `false` if point is to right of segment)
epsilon	epsilon for segment snapping

Returns: squared distance to closest segment or negative value on error

Implements QgsAbstractGeometry.

Definition at line 549 of file qgsgeometrycollection.cpp.

◆ coordinateSequence()

QgsCoordinateSequence QgsGeometryCollection::coordinateSequence ( ) const

overridevirtual

Retrieves the sequence of geometries, rings and nodes.

Returns: coordinate sequence

Implements QgsAbstractGeometry.

Definition at line 518 of file qgsgeometrycollection.cpp.

◆ createEmptyWithSameType()

QgsGeometryCollection * QgsGeometryCollection::createEmptyWithSameType ( ) const

overridevirtual

Creates a new geometry with the same class and same WKB type as the original and transfers ownership.

To create it, the geometry is default constructed and then the WKB is changed.

See also: clone()

Since: 3.0

Implements QgsAbstractGeometry.

Reimplemented in QgsMultiCurve, QgsMultiPoint, QgsMultiSurface, QgsMultiLineString, and QgsMultiPolygon.

Definition at line 111 of file qgsgeometrycollection.cpp.

◆ deleteVertex()

bool QgsGeometryCollection::deleteVertex ( QgsVertexId position )

overridevirtual

Deletes a vertex within the geometry.

Parameters

position vertex id for vertex to delete

Returns: true if delete was successful

See also: insertVertex; moveVertex

Implements QgsAbstractGeometry.

Definition at line 615 of file qgsgeometrycollection.cpp.

◆ dimension()

int QgsGeometryCollection::dimension ( ) const

overridevirtual

Returns the inherent dimension of the geometry.

For example, this is 0 for a point geometry, 1 for a linestring and 2 for a polygon.

Implements QgsAbstractGeometry.

Definition at line 264 of file qgsgeometrycollection.cpp.

◆ draw()

void QgsGeometryCollection::draw ( QPainter & p ) const

overridevirtual

Draws the geometry using the specified QPainter.

Parameters

p	destination QPainter

Implements QgsAbstractGeometry.

Definition at line 302 of file qgsgeometrycollection.cpp.

◆ dropMValue()

bool QgsGeometryCollection::dropMValue ( )

overridevirtual

Drops any measure values which exist in the geometry.

Returns: true if m-values were present and have been removed

See also: addMValue(); dropZValue()

Since: QGIS 2.14

Implements QgsAbstractGeometry.

Definition at line 897 of file qgsgeometrycollection.cpp.

◆ dropZValue()

bool QgsGeometryCollection::dropZValue ( )

overridevirtual

Drops any z-dimensions which exist in the geometry.

Returns: true if Z values were present and have been removed

See also: addZValue(); dropMValue()

Since: QGIS 2.14

Implements QgsAbstractGeometry.

Definition at line 883 of file qgsgeometrycollection.cpp.

◆ filterVertices()

void QgsGeometryCollection::filterVertices ( const std::function< bool(const QgsPoint &) > & filter )

overridevirtual

Filters the vertices from the geometry in place, removing any which do not return true for the filter function check.

Has no meaning when called on a single point geometry.

Depending on the filter used, this may result in an invalid geometry.

Note: Not available in Python bindings

Since: QGIS 3.2

Reimplemented from QgsAbstractGeometry.

Reimplemented in QgsMultiPoint.

Definition at line 911 of file qgsgeometrycollection.cpp.

◆ fromCollectionWkt()

bool QgsGeometryCollection::fromCollectionWkt	(	const QString &	wkt,
		const QVector< QgsAbstractGeometry * > &	subtypes,
		const QString &	defaultChildWkbType = `QString()`
	)

protected

Reads a collection from a WKT string.

Definition at line 676 of file qgsgeometrycollection.cpp.

◆ fromWkb()

bool QgsGeometryCollection::fromWkb ( QgsConstWkbPtr & wkb )

overridevirtual

Sets the geometry from a WKB string.

After successful read the wkb argument will be at the position where the reading has stopped.

See also: fromWkt

Implements QgsAbstractGeometry.

Definition at line 311 of file qgsgeometrycollection.cpp.

◆ fromWkt()

bool QgsGeometryCollection::fromWkt ( const QString & wkt )

overridevirtual

Sets the geometry from a WKT string.

See also: fromWkb

Implements QgsAbstractGeometry.

Reimplemented in QgsMultiCurve, QgsMultiLineString, QgsMultiPoint, QgsMultiSurface, and QgsMultiPolygon.

Definition at line 350 of file qgsgeometrycollection.cpp.

◆ geometryN() [1/2]

QgsAbstractGeometry * QgsGeometryCollection::geometryN ( int n )

Returns a geometry from within the collection.

Parameters

n	index of geometry to return

Definition at line 207 of file qgsgeometrycollection.cpp.

◆ geometryN() [2/2]

const QgsAbstractGeometry* QgsGeometryCollection::geometryN ( int n ) const

inline

Returns a const reference to a geometry from within the collection.

Parameters

n	index of geometry to return

Note: not available in Python bindings

Definition at line 79 of file qgsgeometrycollection.h.

◆ geometryType()

QString QgsGeometryCollection::geometryType ( ) const

overridevirtual

Returns a unique string representing the geometry type.

See also: wkbType; wktTypeStr

Implements QgsAbstractGeometry.

Reimplemented in QgsMultiLineString, QgsMultiPoint, QgsMultiCurve, QgsMultiPolygon, and QgsMultiSurface.

Definition at line 279 of file qgsgeometrycollection.cpp.

◆ hasCurvedSegments()

bool QgsGeometryCollection::hasCurvedSegments ( ) const

overridevirtual

Returns true if the geometry contains curved segments.

Reimplemented from QgsAbstractGeometry.

Definition at line 740 of file qgsgeometrycollection.cpp.

◆ insertGeometry()

bool QgsGeometryCollection::insertGeometry	(	QgsAbstractGeometry *	g,
		int	index
	)

virtual

Inserts a geometry before a specified index and takes ownership.

Returns true in case of success.

Parameters

g	geometry to insert. Ownership is transferred to the collection.
index	position to insert geometry before

Reimplemented in QgsMultiPoint, QgsMultiCurve, QgsMultiLineString, QgsMultiSurface, and QgsMultiPolygon.

Definition at line 238 of file qgsgeometrycollection.cpp.

◆ insertVertex()

bool QgsGeometryCollection::insertVertex	(	QgsVertexId	position,
		const QgsPoint &	vertex
	)

overridevirtual

Inserts a vertex into the geometry.

Parameters

position	vertex id for position of inserted vertex
vertex	vertex to insert

Returns: true if insert was successful

See also: moveVertex; deleteVertex

Implements QgsAbstractGeometry.

Definition at line 585 of file qgsgeometrycollection.cpp.

◆ isEmpty()

bool QgsGeometryCollection::isEmpty ( ) const

overridevirtual

Returns true if the geometry is empty.

Reimplemented from QgsAbstractGeometry.

Definition at line 213 of file qgsgeometrycollection.cpp.

◆ isValid()

bool QgsGeometryCollection::isValid	(	QString &	error,
		int	flags = `0`
	)		const

overridevirtual

Checks validity of the geometry, and returns true if the geometry is valid.

Parameters

error	will be set to the validity error message
flags	indicates optional flags which control the type of validity checking performed (corresponding to QgsGeometry::ValidityFlags).

Returns: true if geometry is valid

Since: QGIS 3.8

Implements QgsAbstractGeometry.

Reimplemented in QgsMultiPoint.

Definition at line 833 of file qgsgeometrycollection.cpp.

◆ length()

double QgsGeometryCollection::length ( ) const

overridevirtual

Returns the planar, 2-dimensional length of the geometry.

Warning: QgsAbstractGeometry objects are inherently Cartesian/planar geometries, and the length returned by this method is calculated using strictly Cartesian mathematics. In contrast, the QgsDistanceArea class exposes methods for calculating the lengths of geometries using geodesic calculations which account for the curvature of the Earth (or any other celestial body).

See also: area(); perimeter()

Reimplemented from QgsAbstractGeometry.

Definition at line 643 of file qgsgeometrycollection.cpp.

◆ moveVertex()

bool QgsGeometryCollection::moveVertex	(	QgsVertexId	position,
		const QgsPoint &	newPos
	)

overridevirtual

Moves a vertex within the geometry.

Parameters

position	vertex id for vertex to move
newPos	new position of vertex

Returns: true if move was successful

See also: insertVertex; deleteVertex

Implements QgsAbstractGeometry.

Definition at line 600 of file qgsgeometrycollection.cpp.

◆ nCoordinates()

int QgsGeometryCollection::nCoordinates ( ) const

overridevirtual

Returns the number of nodes contained in the geometry.

Reimplemented from QgsAbstractGeometry.

Reimplemented in QgsMultiPoint.

Definition at line 536 of file qgsgeometrycollection.cpp.

◆ nextVertex()

bool QgsGeometryCollection::nextVertex	(	QgsVertexId &	id,
		QgsPoint &	vertex
	)		const

overridevirtual

Returns next vertex id and coordinates.

Parameters

id	initial value should be the starting vertex id. The next vertex id will be stored in this variable if found.
vertex	container for found node

Returns: false if at end

Implements QgsAbstractGeometry.

Definition at line 554 of file qgsgeometrycollection.cpp.

◆ numGeometries()

int QgsGeometryCollection::numGeometries ( ) const

inline

Returns the number of geometries within the collection.

Definition at line 51 of file qgsgeometrycollection.h.

◆ operator!=()

bool QgsGeometryCollection::operator!= ( const QgsAbstractGeometry & other ) const

overridevirtual

Implements QgsAbstractGeometry.

Definition at line 106 of file qgsgeometrycollection.cpp.

◆ operator=()

QgsGeometryCollection & QgsGeometryCollection::operator= ( const QgsGeometryCollection & c )

Definition at line 53 of file qgsgeometrycollection.cpp.

◆ operator==()

bool QgsGeometryCollection::operator== ( const QgsAbstractGeometry & other ) const

overridevirtual

Implements QgsAbstractGeometry.

Definition at line 74 of file qgsgeometrycollection.cpp.

◆ partCount()

int QgsGeometryCollection::partCount ( ) const

overridevirtual

Returns count of parts contained in the geometry.

See also: vertexCount; ringCount

Implements QgsAbstractGeometry.

Definition at line 823 of file qgsgeometrycollection.cpp.

◆ perimeter()

double QgsGeometryCollection::perimeter ( ) const

overridevirtual

Returns the planar, 2-dimensional perimeter of the geometry.

Warning: QgsAbstractGeometry objects are inherently Cartesian/planar geometries, and the perimeter returned by this method is calculated using strictly Cartesian mathematics. In contrast, the QgsDistanceArea class exposes methods for calculating the perimeters of geometries using geodesic calculations which account for the curvature of the Earth (or any other celestial body).

See also: area(); length()

Reimplemented from QgsAbstractGeometry.

Definition at line 665 of file qgsgeometrycollection.cpp.

◆ removeDuplicateNodes()

bool QgsGeometryCollection::removeDuplicateNodes	(	double	epsilon = `4 *std::numeric_limits< double >::epsilon()`,
		bool	useZValues = `false`
	)

overridevirtual

Removes duplicate nodes from the geometry, wherever removing the nodes does not result in a degenerate geometry.

The epsilon parameter specifies the tolerance for coordinates when determining that vertices are identical.

By default, z values are not considered when detecting duplicate nodes. E.g. two nodes with the same x and y coordinate but different z values will still be considered duplicate and one will be removed. If useZValues is true, then the z values are also tested and nodes with the same x and y but different z will be maintained.

Note that duplicate nodes are not tested between different parts of a multipart geometry. E.g. a multipoint geometry with overlapping points will not be changed by this method.

The function will return true if nodes were removed, or false if no duplicate nodes were found.

Since: QGIS 3.0

Implements QgsAbstractGeometry.

Definition at line 149 of file qgsgeometrycollection.cpp.

◆ removeGeometry()

bool QgsGeometryCollection::removeGeometry ( int nr )

virtual

Removes a geometry from the collection.

Parameters

nr	index of geometry to remove

Returns: true if removal was successful.

Definition at line 252 of file qgsgeometrycollection.cpp.

◆ reserve()

void QgsGeometryCollection::reserve ( int size )

Attempts to allocate memory for at least size geometries.

If the number of geometries is known in advance, calling this function prior to adding geometries will prevent reallocations and memory fragmentation.

Since: QGIS 3.10

Definition at line 202 of file qgsgeometrycollection.cpp.

◆ ringCount()

int QgsGeometryCollection::ringCount ( int part = 0 ) const

overridevirtual

Returns the number of rings of which this geometry is built.

Implements QgsAbstractGeometry.

Definition at line 813 of file qgsgeometrycollection.cpp.

◆ segmentize()

QgsAbstractGeometry * QgsGeometryCollection::segmentize	(	double	tolerance = `M_PI_2 / 90`,
		SegmentationToleranceType	toleranceType = `MaximumAngle`
	)		const

overridevirtual

Returns a geometry without curves.

Caller takes ownership

Parameters

tolerance	segmentation tolerance
toleranceType	maximum segmentation angle or maximum difference between approximation and curve

Reimplemented from QgsAbstractGeometry.

Definition at line 753 of file qgsgeometrycollection.cpp.

◆ segmentLength()

double QgsGeometryCollection::segmentLength ( QgsVertexId startVertex ) const

overridevirtual

Returns the length of the segment of the geometry which begins at startVertex.

Warning: QgsAbstractGeometry objects are inherently Cartesian/planar geometries, and the lengths returned by this method are calculated using strictly Cartesian mathematics.

Since: QGIS 3.0

Implements QgsAbstractGeometry.

Reimplemented in QgsMultiPoint.

Definition at line 787 of file qgsgeometrycollection.cpp.

◆ snappedToGrid()

QgsGeometryCollection * QgsGeometryCollection::snappedToGrid	(	double	hSpacing,
		double	vSpacing,
		double	dSpacing = `0`,
		double	mSpacing = `0`
	)		const

overridevirtual

Makes a new geometry with all the points or vertices snapped to the closest point of the grid.

Ownership is transferred to the caller.

If the gridified geometry could not be calculated nullptr will be returned. It may generate an invalid geometry (in some corner cases). It can also be thought as rounding the edges and it may be useful for removing errors.

Example

geometry->snappedToGrid(1, 1);

In this case we use a 2D grid of 1x1 to gridify. In this case, it can be thought like rounding the x and y of all the points/vertices to full units (remove all decimals).

Parameters

hSpacing	Horizontal spacing of the grid (x axis). 0 to disable.
vSpacing	Vertical spacing of the grid (y axis). 0 to disable.
dSpacing	Depth spacing of the grid (z axis). 0 (default) to disable.
mSpacing	Custom dimension spacing of the grid (m axis). 0 (default) to disable.

Since: 3.0

Implements QgsAbstractGeometry.

Definition at line 130 of file qgsgeometrycollection.cpp.

◆ swapXy()

void QgsGeometryCollection::swapXy ( )

overridevirtual

Swaps the x and y coordinates from the geometry.

This can be used to repair geometries which have accidentally had their latitude and longitude coordinates reversed.

Since: QGIS 3.2

Implements QgsAbstractGeometry.

Definition at line 931 of file qgsgeometrycollection.cpp.

◆ toCurveType()

QgsGeometryCollection * QgsGeometryCollection::toCurveType ( ) const

overridevirtual

Returns the geometry converted to the more generic curve type.

E.g. QgsLineString -> QgsCompoundCurve, QgsPolygon -> QgsCurvePolygon, QgsMultiLineString -> QgsMultiCurve, QgsMultiPolygon -> QgsMultiSurface

Returns: the converted geometry. Caller takes ownership

Implements QgsAbstractGeometry.

Reimplemented in QgsMultiLineString, QgsMultiPolygon, QgsMultiCurve, QgsMultiPoint, and QgsMultiSurface.

Definition at line 941 of file qgsgeometrycollection.cpp.

◆ transform() [1/2]

void QgsGeometryCollection::transform	(	const QgsCoordinateTransform &	ct,
		QgsCoordinateTransform::TransformDirection	d = `QgsCoordinateTransform::ForwardTransform`,
		bool	transformZ = `false`
	)

overridevirtual

Transforms the geometry using a coordinate transform.

Parameters

ct	coordinate transform
d	transformation direction
transformZ	set to `true` to also transform z coordinates. This requires that the z coordinates in the geometry represent height relative to the vertical datum of the source CRS (generally ellipsoidal heights) and are expressed in its vertical units (generally meters). If `false`, then z coordinates will not be changed by the transform.

Implements QgsAbstractGeometry.

Definition at line 284 of file qgsgeometrycollection.cpp.

◆ transform() [2/2]

void QgsGeometryCollection::transform	(	const QTransform &	t,
		double	zTranslate = `0.0`,
		double	zScale = `1.0`,
		double	mTranslate = `0.0`,
		double	mScale = `1.0`
	)

overridevirtual

Transforms the x and y components of the geometry using a QTransform object t.

Optionally, the geometry's z values can be scaled via zScale and translated via zTranslate. Similarly, m-values can be scaled via mScale and translated via mTranslate.

Implements QgsAbstractGeometry.

Definition at line 293 of file qgsgeometrycollection.cpp.

◆ transformVertices()

void QgsGeometryCollection::transformVertices ( const std::function< QgsPoint(const QgsPoint &) > & transform )

overridevirtual

Transforms the vertices from the geometry in place, applying the transform function to every vertex.

Depending on the transform used, this may result in an invalid geometry.

Transform functions are not permitted to alter the dimensionality of vertices. If a transform which adds (or removes) z/m values is desired, first call the corresponding addZValue() or addMValue() function to change the geometry's dimensionality and then transform.

Note: Not available in Python bindings

Since: QGIS 3.4

Reimplemented from QgsAbstractGeometry.

Definition at line 921 of file qgsgeometrycollection.cpp.

◆ vertexAngle()

double QgsGeometryCollection::vertexAngle ( QgsVertexId vertex ) const

overridevirtual

Returns approximate angle at a vertex.

This is usually the average angle between adjacent segments, and can be pictured as the orientation of a line following the curvature of the geometry at the specified vertex.

Parameters

vertex the vertex id

Returns: rotation in radians, clockwise from north

Implements QgsAbstractGeometry.

Definition at line 771 of file qgsgeometrycollection.cpp.

◆ vertexAt()

QgsPoint QgsGeometryCollection::vertexAt ( QgsVertexId id ) const

overridevirtual

Returns the point corresponding to a specified vertex id.

Implements QgsAbstractGeometry.

Definition at line 828 of file qgsgeometrycollection.cpp.

◆ vertexCount()

int QgsGeometryCollection::vertexCount	(	int	part = `0`,
		int	ring = `0`
	)		const

overridevirtual

Returns the number of vertices of which this geometry is built.

Implements QgsAbstractGeometry.

Definition at line 803 of file qgsgeometrycollection.cpp.

◆ vertexNumberFromVertexId()

int QgsGeometryCollection::vertexNumberFromVertexId ( QgsVertexId id ) const

overridevirtual

Returns the vertex number corresponding to a vertex id.

The vertex numbers start at 0, so a return value of 0 corresponds to the first vertex.

Returns -1 if a corresponding vertex could not be found.

Since: QGIS 3.0

Implements QgsAbstractGeometry.

Reimplemented in QgsMultiPoint.

Definition at line 176 of file qgsgeometrycollection.cpp.

◆ wktOmitChildType()

bool QgsGeometryCollection::wktOmitChildType ( ) const

protectedvirtual

Returns whether child type names are omitted from Wkt representations of the collection.

Since: QGIS 2.12

Reimplemented in QgsMultiPoint, QgsMultiLineString, and QgsMultiPolygon.

Definition at line 952 of file qgsgeometrycollection.cpp.

Member Data Documentation

◆ mGeometries

QVector< QgsAbstractGeometry * > QgsGeometryCollection::mGeometries

protected

Definition at line 317 of file qgsgeometrycollection.h.

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

/build/qgis-3.14.0+99unstable/src/core/geometry/qgsgeometrycollection.h
/build/qgis-3.14.0+99unstable/src/core/geometry/qgsgeometrycollection.cpp

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QgsGeometryCollection() [1/2]

◆ QgsGeometryCollection() [2/2]

◆ ~QgsGeometryCollection()

Member Function Documentation

◆ addGeometry()

◆ addMValue()

◆ addZValue()

◆ adjacentVertices()

◆ area()

◆ asGml2()

◆ asGml3()

◆ asJsonObject()

◆ asKml()

◆ asWkb()

◆ asWkt()

◆ boundary()

◆ boundingBox()

◆ calculateBoundingBox()

◆ cast()

◆ childCount()

◆ childGeometry()

◆ clear()

◆ clearCache()

◆ clone()

◆ closestSegment()

◆ coordinateSequence()

◆ createEmptyWithSameType()

◆ deleteVertex()

◆ dimension()

◆ draw()

◆ dropMValue()

◆ dropZValue()

◆ filterVertices()

◆ fromCollectionWkt()

◆ fromWkb()

◆ fromWkt()

◆ geometryN() [1/2]

◆ geometryN() [2/2]

◆ geometryType()

◆ hasCurvedSegments()

◆ insertGeometry()

◆ insertVertex()

◆ isEmpty()

◆ isValid()

◆ length()

◆ moveVertex()

◆ nCoordinates()

◆ nextVertex()

◆ numGeometries()

◆ operator!=()

◆ operator=()

◆ operator==()

◆ partCount()

◆ perimeter()

◆ removeDuplicateNodes()

◆ removeGeometry()

◆ reserve()

◆ ringCount()

◆ segmentize()

◆ segmentLength()

◆ snappedToGrid()

Example

◆ swapXy()

◆ toCurveType()

◆ transform() [1/2]

◆ transform() [2/2]

◆ transformVertices()

◆ vertexAngle()

◆ vertexAt()

◆ vertexCount()

◆ vertexNumberFromVertexId()

◆ wktOmitChildType()

Member Data Documentation

◆ mGeometries