A renderer that automatically clusters points with the same geographic position. More...

#include <qgspointclusterrenderer.h>

Inheritance diagram for QgsPointClusterRenderer:

[legend]

Public Member Functions
	QgsPointClusterRenderer ()

bool	accept (QgsStyleEntityVisitorInterface *visitor) const override
	Accepts the specified symbology visitor, causing it to visit all symbols associated with the renderer.

QgsPointClusterRenderer *	clone () const override
	Create a deep copy of this renderer.

QgsMarkerSymbol *	clusterSymbol ()
	Returns the symbol used for rendering clustered groups (but not ownership of the symbol).

Qgis::FeatureRendererFlags	flags () const override
	Returns flags associated with the renderer.

QDomElement	save (QDomDocument &doc, const QgsReadWriteContext &context) override
	Stores renderer properties to an XML element.

void	setClusterSymbol (QgsMarkerSymbol *symbol)
	Sets the symbol for rendering clustered groups.

void	startRender (QgsRenderContext &context, const QgsFields &fields) override
	Must be called when a new render cycle is started.

void	stopRender (QgsRenderContext &context) override
	Must be called when a render cycle has finished, to allow the renderer to clean up.

QSet< QString >	usedAttributes (const QgsRenderContext &context) const override
	Returns a list of attributes required by this renderer.

Public Member Functions inherited from QgsPointDistanceRenderer
	QgsPointDistanceRenderer (const QString &rendererName, const QString &labelAttributeName=QString())
	Constructor for QgsPointDistanceRenderer.

bool	accept (QgsStyleEntityVisitorInterface *visitor) const override
	Accepts the specified symbology visitor, causing it to visit all symbols associated with the renderer.

QgsFeatureRenderer::Capabilities	capabilities () override
	Returns details about internals of this renderer.

void	checkLegendSymbolItem (const QString &key, bool state) override
	Sets whether the legend symbology item with the specified ley should be checked.

const QgsFeatureRenderer *	embeddedRenderer () const override
	Returns the current embedded renderer (subrenderer) for this feature renderer.

QString	filter (const QgsFields &fields=QgsFields()) override
	If a renderer does not require all the features this method may be overridden and return an expression used as where clause.

bool	filterNeedsGeometry () const override
	Returns `true` if this renderer requires the geometry to apply the filter.

QString	labelAttributeName () const
	Returns the attribute name used for labeling points, or an empty string if no labeling will be done by the renderer.

QColor	labelColor () const
	Returns the color used for for labeling points.

QFont	labelFont () const
	Returns the font used for labeling points.

QSet< QString >	legendKeysForFeature (const QgsFeature &feature, QgsRenderContext &context) const override
	Returns legend keys matching a specified feature.

QString	legendKeyToExpression (const QString &key, QgsVectorLayer *layer, bool &ok) const override
	Attempts to convert the specified legend rule key to a QGIS expression matching the features displayed using that key.

bool	legendSymbolItemChecked (const QString &key) override
	Returns `true` if the legend symbology item with the specified key is checked.

QgsLegendSymbolList	legendSymbolItems () const override
	Returns a list of symbology items for the legend.

bool	legendSymbolItemsCheckable () const override
	Returns `true` if symbology items in legend are checkable.

double	minimumLabelScale () const
	Returns the minimum map scale (i.e.

QgsSymbol *	originalSymbolForFeature (const QgsFeature &feature, QgsRenderContext &context) const override
	Returns symbol for feature.

QgsSymbolList	originalSymbolsForFeature (const QgsFeature &feature, QgsRenderContext &context) const override
	Equivalent of originalSymbolsForFeature() call extended to support renderers that may use more symbols per feature - similar to symbolsForFeature()

bool	renderFeature (const QgsFeature &feature, QgsRenderContext &context, int layer=-1, bool selected=false, bool drawVertexMarker=false) override
	Render a feature using this renderer in the given context.

void	setEmbeddedRenderer (QgsFeatureRenderer *r) override
	Sets an embedded renderer (subrenderer) for this feature renderer.

void	setLabelAttributeName (const QString &name)
	Sets the attribute name for labeling points.

void	setLabelColor (const QColor &color)
	Sets the color to use for for labeling points.

void	setLabelFont (const QFont &font)
	Sets the font used for labeling points.

void	setLegendSymbolItem (const QString &key, QgsSymbol *symbol) override
	Sets the symbol to be used for a legend symbol item.

void	setMinimumLabelScale (double scale)
	Sets the minimum map scale (i.e.

void	setTolerance (double distance)
	Sets the tolerance distance for grouping points.

void	setToleranceMapUnitScale (const QgsMapUnitScale &scale)
	Sets the map unit scale object for the distance tolerance.

void	setToleranceUnit (Qgis::RenderUnit unit)
	Sets the units for the tolerance distance.

void	startRender (QgsRenderContext &context, const QgsFields &fields) override
	Must be called when a new render cycle is started.

void	stopRender (QgsRenderContext &context) override
	Must be called when a render cycle has finished, to allow the renderer to clean up.

QgsSymbol *	symbolForFeature (const QgsFeature &feature, QgsRenderContext &context) const override
	To be overridden.

QgsSymbolList	symbols (QgsRenderContext &context) const override
	Returns list of symbols used by the renderer.

QgsSymbolList	symbolsForFeature (const QgsFeature &feature, QgsRenderContext &context) const override
	Returns list of symbols used for rendering the feature.

double	tolerance () const
	Returns the tolerance distance for grouping points.

const QgsMapUnitScale &	toleranceMapUnitScale () const
	Returns the map unit scale object for the distance tolerance.

Qgis::RenderUnit	toleranceUnit () const
	Returns the units for the tolerance distance.

void	toSld (QDomDocument &doc, QDomElement &element, const QVariantMap &props=QVariantMap()) const override
	used from subclasses to create SLD Rule elements following SLD v1.1 specs

QSet< QString >	usedAttributes (const QgsRenderContext &context) const override
	Returns a list of attributes required by this renderer.

bool	willRenderFeature (const QgsFeature &feature, QgsRenderContext &context) const override
	Returns whether the renderer will render a feature or not.

Public Member Functions inherited from QgsFeatureRenderer
virtual	~QgsFeatureRenderer ()

virtual bool	canSkipRender ()
	Returns `true` if the renderer can be entirely skipped, i.e.

void	copyRendererData (QgsFeatureRenderer *destRenderer) const
	Clones generic renderer data to another renderer.

virtual QList< QgsLayerTreeModelLegendNode * >	createLegendNodes (QgsLayerTreeLayer *nodeLayer) const
	Returns a list of legend nodes to be used for the legend for the renderer.

QgsPropertyCollection &	dataDefinedProperties ()
	Returns a reference to the renderer's property collection, used for data defined overrides.

const QgsPropertyCollection &	dataDefinedProperties () const
	Returns a reference to the renderer's property collection, used for data defined overrides.

virtual QString	dump () const
	Returns debug information about this renderer.

bool	forceRasterRender () const
	Returns whether the renderer must render as a raster.

virtual QString	legendClassificationAttribute () const
	If supported by the renderer, return classification attribute for the use in legend.

QSet< QString >	legendKeys () const
	Returns the set of all legend keys used by the renderer.

double	maximumExtentBuffer (QgsRenderContext &context) const
	Returns the maximum extent buffer found in this renderer's symbols.

virtual void	modifyRequestExtent (QgsRectangle &extent, QgsRenderContext &context)
	Allows for a renderer to modify the extent of a feature request prior to rendering.

QgsFeatureRequest::OrderBy	orderBy () const
	Gets the order in which features shall be processed by this renderer.

bool	orderByEnabled () const
	Returns whether custom ordering will be applied before features are processed by this renderer.

QgsPaintEffect *	paintEffect () const
	Returns the current paint effect for the renderer.

double	referenceScale () const
	Returns the symbology reference scale.

void	setDataDefinedProperties (const QgsPropertyCollection &collection)
	Sets the renderer's property collection, used for data defined overrides.

void	setDataDefinedProperty (Property key, const QgsProperty &property)
	Sets a data defined property for the renderer.

void	setForceRasterRender (bool forceRaster)
	Sets whether the renderer should be rendered to a raster destination.

void	setOrderBy (const QgsFeatureRequest::OrderBy &orderBy)
	Define the order in which features shall be processed by this renderer.

void	setOrderByEnabled (bool enabled)
	Sets whether custom ordering should be applied before features are processed by this renderer.

void	setPaintEffect (QgsPaintEffect *effect)
	Sets the current paint effect for the renderer.

void	setReferenceScale (double scale)
	Sets the symbology reference scale.

void	setUsingSymbolLevels (bool usingSymbolLevels)

void	setVertexMarkerAppearance (Qgis::VertexMarkerType type, double size)
	Sets type and size of editing vertex markers for subsequent rendering.

QString	type () const

virtual bool	usesEmbeddedSymbols () const
	Returns `true` if the renderer uses embedded symbols for features.

bool	usingSymbolLevels () const

virtual QDomElement	writeSld (QDomDocument &doc, const QString &styleName, const QVariantMap &props=QVariantMap()) const
	create the SLD UserStyle element following the SLD v1.1 specs with the given name

Static Public Member Functions
static QgsPointClusterRenderer *	convertFromRenderer (const QgsFeatureRenderer *renderer)
	Creates a QgsPointClusterRenderer from an existing renderer.

static QgsFeatureRenderer *	create (QDomElement &symbologyElem, const QgsReadWriteContext &context)
	Creates a renderer from XML element.

Static Public Member Functions inherited from QgsFeatureRenderer
static QgsFeatureRenderer *	defaultRenderer (Qgis::GeometryType geomType)
	Returns a new renderer - used by default in vector layers.

static QgsFeatureRenderer *	load (QDomElement &symbologyElem, const QgsReadWriteContext &context)
	create a renderer from XML element

static QgsFeatureRenderer *	loadSld (const QDomNode &node, Qgis::GeometryType geomType, QString &errorMessage)
	Create a new renderer according to the information contained in the UserStyle element of a SLD style document.

static const QgsPropertiesDefinition &	propertyDefinitions ()
	Returns the symbol property definitions.

Additional Inherited Members
Public Types inherited from QgsPointDistanceRenderer
typedef QList< QgsPointDistanceRenderer::GroupedFeature >	ClusteredGroup
	A group of clustered points (ie features within the distance tolerance).

Public Types inherited from QgsFeatureRenderer
typedef QFlags< Capability >	Capabilities

enum	Capability { SymbolLevels = 1 , MoreSymbolsPerFeature = 1 << 2 , Filter = 1 << 3 , ScaleDependent = 1 << 4 }
	Used to specify details about a renderer. More...

enum class	Property : int { HeatmapRadius , HeatmapMaximum }
	Data definable properties for renderers. More...

Protected Member Functions inherited from QgsPointDistanceRenderer
void	drawLabels (QPointF centerPoint, QgsSymbolRenderContext &context, const QList< QPointF > &labelShifts, const ClusteredGroup &group) const
	Renders the labels for a group.

Protected Member Functions inherited from QgsFeatureRenderer
	QgsFeatureRenderer (const QString &type)

void	renderFeatureWithSymbol (const QgsFeature &feature, QgsSymbol *symbol, QgsRenderContext &context, int layer, bool selected, bool drawVertexMarker)
	Render the feature with the symbol using context.

void	renderVertexMarker (QPointF pt, QgsRenderContext &context)
	render editing vertex marker at specified point

void	renderVertexMarkerPolygon (QPolygonF &pts, QList< QPolygonF > *rings, QgsRenderContext &context)
	render editing vertex marker for a polygon

void	renderVertexMarkerPolyline (QPolygonF &pts, QgsRenderContext &context)
	render editing vertex marker for a polyline

void	saveRendererData (QDomDocument &doc, QDomElement &element, const QgsReadWriteContext &context)
	Saves generic renderer data into the specified element.

Static Protected Member Functions inherited from QgsFeatureRenderer
static QPointF	_getPoint (QgsRenderContext &context, const QgsPoint &point)
	Creates a point in screen coordinates from a wkb string in map coordinates.

static void	convertSymbolRotation (QgsSymbol *symbol, const QString &field)

static void	convertSymbolSizeScale (QgsSymbol *symbol, Qgis::ScaleMethod method, const QString &field)

Protected Attributes inherited from QgsPointDistanceRenderer
QList< ClusteredGroup >	mClusteredGroups
	Groups of features that are considered clustered together.

bool	mDrawLabels
	Whether labels should be drawn for points. This is set internally from startRender() depending on scale denominator.

QMap< QgsFeatureId, int >	mGroupIndex
	Mapping of feature ID to the feature's group index.

QMap< QgsFeatureId, QgsPointXY >	mGroupLocations
	Mapping of feature ID to approximate group location.

QString	mLabelAttributeName
	Attribute name for labeling. An empty string indicates that no labels should be rendered.

QColor	mLabelColor
	Label text color.

QFont	mLabelFont
	Label font.

int	mLabelIndex
	Label attribute index (or -1 if none). This index is not stored, it is requested in the startRender() method.

double	mMinLabelScale = 0
	Maximum scale denominator for label display. A zero value indicates no scale limitation.

std::unique_ptr< QgsFeatureRenderer >	mRenderer
	Embedded base renderer. This can be used for rendering individual, isolated points.

QgsSpatialIndex *	mSpatialIndex = nullptr
	Spatial index for fast lookup of nearby points.

double	mTolerance
	Distance tolerance. Points that are closer together than this distance are considered clustered.

QgsMapUnitScale	mToleranceMapUnitScale
	Map unit scale for distance tolerance.

Qgis::RenderUnit	mToleranceUnit
	Unit for distance tolerance.

Protected Attributes inherited from QgsFeatureRenderer
double	mCurrentVertexMarkerSize = 2
	The current size of editing marker.

Qgis::VertexMarkerType	mCurrentVertexMarkerType = Qgis::VertexMarkerType::Cross
	The current type of editing marker.

bool	mForceRaster = false

QgsFeatureRequest::OrderBy	mOrderBy

bool	mOrderByEnabled = false

QgsPaintEffect *	mPaintEffect = nullptr

double	mReferenceScale = -1.0

QString	mType

bool	mUsingSymbolLevels = false

Detailed Description

A renderer that automatically clusters points with the same geographic position.

Definition at line 30 of file qgspointclusterrenderer.h.

Constructor & Destructor Documentation

◆ QgsPointClusterRenderer()

QgsPointClusterRenderer::QgsPointClusterRenderer ( )

Definition at line 29 of file qgspointclusterrenderer.cpp.

Member Function Documentation

◆ accept()

bool QgsPointClusterRenderer::accept ( QgsStyleEntityVisitorInterface * visitor ) const

overridevirtual

Accepts the specified symbology visitor, causing it to visit all symbols associated with the renderer.

Returns true if the visitor should continue visiting other objects, or false if visiting should be canceled.

Since: QGIS 3.10

Reimplemented from QgsFeatureRenderer.

Definition at line 168 of file qgspointclusterrenderer.cpp.

◆ clone()

QgsPointClusterRenderer * QgsPointClusterRenderer::clone ( ) const

overridevirtual

Create a deep copy of this renderer.

Should be implemented by all subclasses and generate a proper subclass.

Returns: A copy of this renderer

Implements QgsFeatureRenderer.

Definition at line 55 of file qgspointclusterrenderer.cpp.

◆ clusterSymbol()

QgsMarkerSymbol * QgsPointClusterRenderer::clusterSymbol ( )

Returns the symbol used for rendering clustered groups (but not ownership of the symbol).

See also: setClusterSymbol()

Definition at line 131 of file qgspointclusterrenderer.cpp.

◆ convertFromRenderer()

QgsPointClusterRenderer * QgsPointClusterRenderer::convertFromRenderer ( const QgsFeatureRenderer * renderer )

static

Creates a QgsPointClusterRenderer from an existing renderer.

Returns: a new renderer if the conversion was possible, otherwise nullptr.

Definition at line 188 of file qgspointclusterrenderer.cpp.

◆ create()

QgsFeatureRenderer * QgsPointClusterRenderer::create	(	QDomElement &	symbologyElem,
		const QgsReadWriteContext &	context
	)

static

Creates a renderer from XML element.

Definition at line 108 of file qgspointclusterrenderer.cpp.

◆ flags()

Qgis::FeatureRendererFlags QgsPointClusterRenderer::flags ( ) const

overridevirtual

Returns flags associated with the renderer.

Since: QGIS 3.40

Reimplemented from QgsFeatureRenderer.

Definition at line 45 of file qgspointclusterrenderer.cpp.

◆ save()

QDomElement QgsPointClusterRenderer::save	(	QDomDocument &	doc,
		const QgsReadWriteContext &	context
	)

overridevirtual

Stores renderer properties to an XML element.

Subclasses which override this method should call saveRendererData() as part of their implementation in order to store all common base class properties in the returned DOM element.

Reimplemented from QgsFeatureRenderer.

Definition at line 136 of file qgspointclusterrenderer.cpp.

◆ setClusterSymbol()

void QgsPointClusterRenderer::setClusterSymbol ( QgsMarkerSymbol * symbol )

Sets the symbol for rendering clustered groups.

Parameters

symbol new cluster symbol. Ownership is transferred to the renderer.

See also: clusterSymbol()

Definition at line 183 of file qgspointclusterrenderer.cpp.

◆ startRender()

void QgsPointClusterRenderer::startRender	(	QgsRenderContext &	context,
		const QgsFields &	fields
	)

overridevirtual

Must be called when a new render cycle is started.

A call to startRender() must always be followed by a corresponding call to stopRender() after all features have been rendered.

Parameters

context	Additional information passed to the renderer about the job which will be rendered
fields	The fields available for rendering

See also: stopRender()

Warning: This method is not thread safe. Before calling startRender() in a non-main thread, the renderer should instead be cloned and startRender()/stopRender() called on the clone.

Reimplemented from QgsFeatureRenderer.

Definition at line 90 of file qgspointclusterrenderer.cpp.

◆ stopRender()

void QgsPointClusterRenderer::stopRender ( QgsRenderContext & context )

overridevirtual

Must be called when a render cycle has finished, to allow the renderer to clean up.

Calls to stopRender() must always be preceded by a call to startRender().

Warning: This method is not thread safe. Before calling startRender() in a non-main thread, the renderer should instead be cloned and startRender()/stopRender() called on the clone.

See also: startRender()

Reimplemented from QgsFeatureRenderer.

Definition at line 99 of file qgspointclusterrenderer.cpp.

◆ usedAttributes()

QSet< QString > QgsPointClusterRenderer::usedAttributes ( const QgsRenderContext & context ) const

overridevirtual

Returns a list of attributes required by this renderer.

Attributes not listed in here may not have been requested from the provider at rendering time.

Returns: A set of attributes

Implements QgsFeatureRenderer.

Definition at line 160 of file qgspointclusterrenderer.cpp.

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

/build/qgis-3.41.0+git20241214+cea29feecf2+99sid/src/core/symbology/qgspointclusterrenderer.h
/build/qgis-3.41.0+git20241214+cea29feecf2+99sid/src/core/symbology/qgspointclusterrenderer.cpp

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QgsPointClusterRenderer()

Member Function Documentation

◆ accept()

◆ clone()

◆ clusterSymbol()

◆ convertFromRenderer()

◆ create()

◆ flags()

◆ save()

◆ setClusterSymbol()

◆ startRender()

◆ stopRender()

◆ usedAttributes()