A renderer that automatically displaces points with the same geographic location. More...

#include <qgspointdisplacementrenderer.h>

Inheritance diagram for QgsPointDisplacementRenderer:

[legend]

Public Types
enum	Placement { Ring , ConcentricRings , Grid }
	Placement methods for dispersing points. More...

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...

Public Member Functions
	QgsPointDisplacementRenderer (const QString &labelAttributeName=QString())
	Constructor for QgsPointDisplacementRenderer.

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

QgsMarkerSymbol *	centerSymbol ()
	Returns the symbol for the center of a displacement group (but not ownership of the symbol).

QColor	circleColor () const
	Returns the color used for drawing the displacement group circle.

double	circleRadiusAddition () const
	Returns the factor for increasing the ring size of displacement groups.

double	circleWidth () const
	Returns the line width for the displacement group circle in mm.

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

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

double	labelDistanceFactor () const
	Returns the factor for label distance from the symbol.

Placement	placement () const
	Returns the placement method used for dispersing the points.

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

void	setCenterSymbol (QgsMarkerSymbol *symbol)
	Sets the center symbol for a displacement group.

void	setCircleColor (const QColor &color)
	Sets the color used for drawing the displacement group circle.

void	setCircleRadiusAddition (double distance)
	Sets a factor for increasing the ring size of displacement groups.

void	setCircleWidth (double width)
	Sets the line width for the displacement group circle.

void	setLabelDistanceFactor (double factor)
	Sets a factor for increasing the label distances from the symbol.

void	setPlacement (Placement placement)
	Sets the placement method used for dispersing the points.

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 QgsPointDisplacementRenderer *	convertFromRenderer (const QgsFeatureRenderer *renderer)
	Creates a QgsPointDisplacementRenderer from an existing renderer.

static QgsFeatureRenderer *	create (QDomElement &symbologyElem, const QgsReadWriteContext &context)
	Create 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
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 displaces points with the same geographic location.

Definition at line 30 of file qgspointdisplacementrenderer.h.

Member Enumeration Documentation

◆ Placement

enum QgsPointDisplacementRenderer::Placement

Placement methods for dispersing points.

Enumerator
Ring	Place points in a single ring around group.
ConcentricRings	Place points in concentric rings around group.
Grid	Place points in a grid around group.

Definition at line 37 of file qgspointdisplacementrenderer.h.

Constructor & Destructor Documentation

◆ QgsPointDisplacementRenderer()

QgsPointDisplacementRenderer::QgsPointDisplacementRenderer ( const QString & labelAttributeName = QString() )

Constructor for QgsPointDisplacementRenderer.

Parameters

labelAttributeName optional attribute name for labeling points

Definition at line 31 of file qgspointdisplacementrenderer.cpp.

Member Function Documentation

◆ accept()

bool QgsPointDisplacementRenderer::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 249 of file qgspointdisplacementrenderer.cpp.

◆ centerSymbol()

QgsMarkerSymbol * QgsPointDisplacementRenderer::centerSymbol ( )

Returns the symbol for the center of a displacement group (but not ownership of the symbol).

See also: setCenterSymbol()

Definition at line 203 of file qgspointdisplacementrenderer.cpp.

◆ circleColor()

QColor QgsPointDisplacementRenderer::circleColor ( ) const

inline

Returns the color used for drawing the displacement group circle.

See also: setCircleColor(); circleWidth()

Definition at line 89 of file qgspointdisplacementrenderer.h.

◆ circleRadiusAddition()

double QgsPointDisplacementRenderer::circleRadiusAddition ( ) const

inline

Returns the factor for increasing the ring size of displacement groups.

See also: setCircleRadiusAddition()

Definition at line 102 of file qgspointdisplacementrenderer.h.

◆ circleWidth()

double QgsPointDisplacementRenderer::circleWidth ( ) const

inline

Returns the line width for the displacement group circle in mm.

See also: setCircleWidth(); circleColor()

Definition at line 74 of file qgspointdisplacementrenderer.h.

◆ clone()

QgsPointDisplacementRenderer * QgsPointDisplacementRenderer::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 48 of file qgspointdisplacementrenderer.cpp.

◆ convertFromRenderer()

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

static

Creates a QgsPointDisplacementRenderer from an existing renderer.

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

Definition at line 480 of file qgspointdisplacementrenderer.cpp.

◆ create()

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

static

Create a renderer from XML element.

Definition at line 166 of file qgspointdisplacementrenderer.cpp.

◆ flags()

Qgis::FeatureRendererFlags QgsPointDisplacementRenderer::flags ( ) const

overridevirtual

Returns flags associated with the renderer.

Since: QGIS 3.40

Reimplemented from QgsFeatureRenderer.

Definition at line 38 of file qgspointdisplacementrenderer.cpp.

◆ labelDistanceFactor()

double QgsPointDisplacementRenderer::labelDistanceFactor ( ) const

inline

Returns the factor for label distance from the symbol.

See also: setLabelDistanceFactor()

Since: QGIS 3.8

Definition at line 117 of file qgspointdisplacementrenderer.h.

◆ placement()

Placement QgsPointDisplacementRenderer::placement ( ) const

inline

Returns the placement method used for dispersing the points.

See also: setPlacement()

Definition at line 123 of file qgspointdisplacementrenderer.h.

◆ save()

QDomElement QgsPointDisplacementRenderer::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 208 of file qgspointdisplacementrenderer.cpp.

◆ setCenterSymbol()

void QgsPointDisplacementRenderer::setCenterSymbol ( QgsMarkerSymbol * symbol )

Sets the center symbol for a displacement group.

Parameters

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

See also: centerSymbol()

Definition at line 264 of file qgspointdisplacementrenderer.cpp.

◆ setCircleColor()

void QgsPointDisplacementRenderer::setCircleColor ( const QColor & color )

inline

Sets the color used for drawing the displacement group circle.

Parameters

color circle color

See also: circleColor(); setCircleWidth()

Definition at line 82 of file qgspointdisplacementrenderer.h.

◆ setCircleRadiusAddition()

void QgsPointDisplacementRenderer::setCircleRadiusAddition ( double distance )

inline

Sets a factor for increasing the ring size of displacement groups.

Parameters

distance addition factor

See also: circleRadiusAddition()

Definition at line 96 of file qgspointdisplacementrenderer.h.

◆ setCircleWidth()

void QgsPointDisplacementRenderer::setCircleWidth ( double width )

inline

Sets the line width for the displacement group circle.

Parameters

width line width in mm

See also: circleWidth(); setCircleColor()

Definition at line 67 of file qgspointdisplacementrenderer.h.

◆ setLabelDistanceFactor()

void QgsPointDisplacementRenderer::setLabelDistanceFactor ( double factor )

inline

Sets a factor for increasing the label distances from the symbol.

Parameters

factor addition factor

See also: labelDistanceFactor()

Since: QGIS 3.8

Definition at line 110 of file qgspointdisplacementrenderer.h.

◆ setPlacement()

void QgsPointDisplacementRenderer::setPlacement ( Placement placement )

inline

Sets the placement method used for dispersing the points.

Parameters

placement placement method

See also: placement()

Definition at line 130 of file qgspointdisplacementrenderer.h.

◆ startRender()

void QgsPointDisplacementRenderer::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 147 of file qgspointdisplacementrenderer.cpp.

◆ stopRender()

void QgsPointDisplacementRenderer::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 157 of file qgspointdisplacementrenderer.cpp.

◆ usedAttributes()

QSet< QString > QgsPointDisplacementRenderer::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 241 of file qgspointdisplacementrenderer.cpp.

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

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

Public Types

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Member Enumeration Documentation

◆ Placement

Constructor & Destructor Documentation

◆ QgsPointDisplacementRenderer()

Member Function Documentation

◆ accept()

◆ centerSymbol()

◆ circleColor()

◆ circleRadiusAddition()

◆ circleWidth()

◆ clone()

◆ convertFromRenderer()

◆ create()

◆ flags()

◆ labelDistanceFactor()

◆ placement()

◆ save()

◆ setCenterSymbol()

◆ setCircleColor()

◆ setCircleRadiusAddition()

◆ setCircleWidth()

◆ setLabelDistanceFactor()

◆ setPlacement()

◆ startRender()

◆ stopRender()

◆ usedAttributes()