An abstract base class for distance based point renderers (e.g., clusterer and displacement renderers). QgsPointDistanceRenderer handles calculation of point clusters using a distance based threshold. Subclasses must implement drawGroup() to handle the rendering of individual point clusters in the desired style. More...

#include <qgspointdistancerenderer.h>

Inheritance diagram for QgsPointDistanceRenderer:

[legend]

Classes
struct	GroupedFeature
	Contains properties for a feature within a clustered group. More...

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

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

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

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

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

void	checkLegendSymbolItem (const QString &key, bool state) override
	item in symbology was checked More...

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

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. More...

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

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

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

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

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

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. More...

bool	legendSymbolItemChecked (const QString &key) override
	items of symbology items in legend is checked More...

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

bool	legendSymbolItemsCheckable () const override
	items of symbology items in legend should be checkable More...

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

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

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() More...

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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 More...

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

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

Public Member Functions inherited from QgsFeatureRenderer
virtual	~QgsFeatureRenderer ()

virtual QgsFeatureRenderer *	clone () const =0
	Create a deep copy of this renderer. More...

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

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

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

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

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

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

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

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

double	referenceScale () const
	Returns the symbology reference scale. More...

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

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

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

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

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

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

void	setUsingSymbolLevels (bool usingSymbolLevels)

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

QString	type () const

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

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 More...

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

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) SIP_THROW(QgsCsException)
	Render the feature with the symbol using context. More...

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

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

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

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

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

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

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

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

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

QColor	mLabelColor
	Label text color. More...

QFont	mLabelFont
	Label font. More...

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

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

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

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

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

QgsMapUnitScale	mToleranceMapUnitScale
	Map unit scale for distance tolerance. More...

QgsUnitTypes::RenderUnit	mToleranceUnit
	Unit for distance tolerance. More...

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

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

bool	mForceRaster = false

QgsFeatureRequest::OrderBy	mOrderBy

bool	mOrderByEnabled = false

QgsPaintEffect *	mPaintEffect = nullptr

double	mReferenceScale = -1.0

QString	mType

bool	mUsingSymbolLevels = false

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

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

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

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. More...

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

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

Detailed Description

An abstract base class for distance based point renderers (e.g., clusterer and displacement renderers). QgsPointDistanceRenderer handles calculation of point clusters using a distance based threshold. Subclasses must implement drawGroup() to handle the rendering of individual point clusters in the desired style.

Since: QGIS 3.0

Definition at line 41 of file qgspointdistancerenderer.h.

Member Typedef Documentation

◆ ClusteredGroup

typedef QList< QgsPointDistanceRenderer::GroupedFeature > QgsPointDistanceRenderer::ClusteredGroup

A group of clustered points (ie features within the distance tolerance).

Definition at line 76 of file qgspointdistancerenderer.h.

Constructor & Destructor Documentation

◆ QgsPointDistanceRenderer()

QgsPointDistanceRenderer::QgsPointDistanceRenderer	(	const QString &	rendererName,
		const QString &	labelAttributeName = `QString()`
	)

Constructor for QgsPointDistanceRenderer.

Parameters

rendererName	name of renderer for registry
labelAttributeName	optional attribute for labeling points

Definition at line 33 of file qgspointdistancerenderer.cpp.

Member Function Documentation

◆ accept()

bool QgsPointDistanceRenderer::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 218 of file qgspointdistancerenderer.cpp.

◆ capabilities()

QgsFeatureRenderer::Capabilities QgsPointDistanceRenderer::capabilities ( )

overridevirtual

Returns details about internals of this renderer.

E.g. if you only want to deal with visible features:

if not renderer.capabilities().testFlag(QgsFeatureRenderer.Filter) or renderer.willRenderFeature(feature, context):
    deal_with_my_feature()
else:
    skip_the_curren_feature()

Reimplemented from QgsFeatureRenderer.

Definition at line 246 of file qgspointdistancerenderer.cpp.

◆ checkLegendSymbolItem()

void QgsPointDistanceRenderer::checkLegendSymbolItem	(	const QString &	key,
		bool	state
	)

overridevirtual

item in symbology was checked

Since: QGIS 2.5

Reimplemented from QgsFeatureRenderer.

Definition at line 202 of file qgspointdistancerenderer.cpp.

◆ drawLabels()

void QgsPointDistanceRenderer::drawLabels	(	QPointF	centerPoint,
		QgsSymbolRenderContext &	context,
		const QList< QPointF > &	labelShifts,
		const ClusteredGroup &	group
	)		const

protected

Renders the labels for a group.

Parameters

centerPoint	center point of group
context	destination render context
labelShifts	displacement for individual label positions
group	group of clustered features to label

Note: may not be available in Python bindings on some platforms

Definition at line 417 of file qgspointdistancerenderer.cpp.

◆ embeddedRenderer()

const QgsFeatureRenderer * QgsPointDistanceRenderer::embeddedRenderer ( ) const

overridevirtual

Returns the current embedded renderer (subrenderer) for this feature renderer.

The base class implementation does not use subrenderers and will always return nullptr.

See also: setEmbeddedRenderer()

Since: QGIS 2.16

Reimplemented from QgsFeatureRenderer.

Definition at line 173 of file qgspointdistancerenderer.cpp.

◆ filter()

QString QgsPointDistanceRenderer::filter ( const QgsFields & fields = QgsFields() )

overridevirtual

If a renderer does not require all the features this method may be overridden and return an expression used as where clause.

This will be called once after startRender() and before the first call to renderFeature(). By default this returns a null string and all features will be requested. You do not need to specify the extent in here, this is taken care of separately and will be combined with a filter returned from this method.

Returns: An expression used as where clause

Reimplemented from QgsFeatureRenderer.

Definition at line 210 of file qgspointdistancerenderer.cpp.

◆ filterNeedsGeometry()

bool QgsPointDistanceRenderer::filterNeedsGeometry ( ) const

overridevirtual

Returns true if this renderer requires the geometry to apply the filter.

Reimplemented from QgsFeatureRenderer.

Definition at line 241 of file qgspointdistancerenderer.cpp.

◆ labelAttributeName()

QString QgsPointDistanceRenderer::labelAttributeName ( ) const

inline

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

See also: setLabelAttributeName(); labelFont(); minimumLabelScale(); labelColor()

Definition at line 128 of file qgspointdistancerenderer.h.

◆ labelColor()

QColor QgsPointDistanceRenderer::labelColor ( ) const

inline

Returns the color used for for labeling points.

See also: setLabelColor(); labelAttributeName(); labelFont()

Definition at line 178 of file qgspointdistancerenderer.h.

◆ labelFont()

QFont QgsPointDistanceRenderer::labelFont ( ) const

inline

Returns the font used for labeling points.

See also: setLabelFont(); labelAttributeName(); labelColor()

Definition at line 145 of file qgspointdistancerenderer.h.

◆ legendKeysForFeature()

QSet< QString > QgsPointDistanceRenderer::legendKeysForFeature	(	const QgsFeature &	feature,
		QgsRenderContext &	context
	)		const

overridevirtual

Returns legend keys matching a specified feature.

Since: QGIS 2.14

Reimplemented from QgsFeatureRenderer.

Definition at line 296 of file qgspointdistancerenderer.cpp.

◆ legendKeyToExpression()

QString QgsPointDistanceRenderer::legendKeyToExpression	(	const QString &	key,
		QgsVectorLayer *	layer,
		bool &	ok
	)		const

overridevirtual

Attempts to convert the specified legend rule key to a QGIS expression matching the features displayed using that key.

Parameters

key	legend key
layer	associated vector layer
ok	will be set to `true` if legend key was successfully converted to a filter expression

Returns: QGIS expression string for matching features with the specified key

Since: QGIS 3.26

Reimplemented from QgsFeatureRenderer.

Definition at line 303 of file qgspointdistancerenderer.cpp.

◆ legendSymbolItemChecked()

bool QgsPointDistanceRenderer::legendSymbolItemChecked ( const QString & key )

overridevirtual

items of symbology items in legend is checked

Since: QGIS 2.5

Reimplemented from QgsFeatureRenderer.

Definition at line 194 of file qgspointdistancerenderer.cpp.

◆ legendSymbolItems()

QgsLegendSymbolList QgsPointDistanceRenderer::legendSymbolItems ( ) const

overridevirtual

Returns a list of symbology items for the legend.

Since: QGIS 2.6

Reimplemented from QgsFeatureRenderer.

Definition at line 375 of file qgspointdistancerenderer.cpp.

◆ legendSymbolItemsCheckable()

bool QgsPointDistanceRenderer::legendSymbolItemsCheckable ( ) const

overridevirtual

items of symbology items in legend should be checkable

Since: QGIS 2.5

Reimplemented from QgsFeatureRenderer.

Definition at line 186 of file qgspointdistancerenderer.cpp.

◆ minimumLabelScale()

double QgsPointDistanceRenderer::minimumLabelScale ( ) const

inline

Returns the minimum map scale (i.e.

most "zoomed out") at which points should be labeled by the renderer. The scale value indicates the scale denominator, e.g. 1000.0 for a 1:1000 map.

See also: setMinimumLabelScale(); labelAttributeName()

Definition at line 161 of file qgspointdistancerenderer.h.

◆ originalSymbolForFeature()

QgsSymbol * QgsPointDistanceRenderer::originalSymbolForFeature	(	const QgsFeature &	feature,
		QgsRenderContext &	context
	)		const

overridevirtual

Returns symbol for feature.

The difference compared to symbolForFeature() is that it returns original symbol which can be used as an identifier for renderer's rule - the former may return a temporary replacement of a symbol for use in rendering.

Since: QGIS 2.12

Reimplemented from QgsFeatureRenderer.

Definition at line 273 of file qgspointdistancerenderer.cpp.

◆ originalSymbolsForFeature()

QgsSymbolList QgsPointDistanceRenderer::originalSymbolsForFeature	(	const QgsFeature &	feature,
		QgsRenderContext &	context
	)		const

overridevirtual

Equivalent of originalSymbolsForFeature() call extended to support renderers that may use more symbols per feature - similar to symbolsForFeature()

Since: QGIS 2.12

Reimplemented from QgsFeatureRenderer.

Definition at line 289 of file qgspointdistancerenderer.cpp.

◆ renderFeature()

bool QgsPointDistanceRenderer::renderFeature	(	const QgsFeature &	feature,
		QgsRenderContext &	context,
		int	layer = `-1`,
		bool	selected = `false`,
		bool	drawVertexMarker = `false`
	)

overridevirtual

Render a feature using this renderer in the given context.

Must be called between startRender() and stopRender() calls. Default implementation renders a symbol as determined by symbolForFeature() call. Returns true if the feature has been returned (this is used for example to determine whether the feature may be labelled).

If layer is not -1, the renderer should draw only a particular layer from symbols (in order to support symbol level rendering).

See also: startRender(); stopRender()

Reimplemented from QgsFeatureRenderer.

Definition at line 51 of file qgspointdistancerenderer.cpp.

◆ setEmbeddedRenderer()

void QgsPointDistanceRenderer::setEmbeddedRenderer ( QgsFeatureRenderer * subRenderer )

overridevirtual

Sets an embedded renderer (subrenderer) for this feature renderer.

The base class implementation does nothing with subrenderers, but individual derived classes can use these to modify their behavior.

Parameters

subRenderer the embedded renderer. Ownership will be transferred.

See also: embeddedRenderer()

Since: QGIS 2.16

Reimplemented from QgsFeatureRenderer.

Definition at line 168 of file qgspointdistancerenderer.cpp.

◆ setLabelAttributeName()

void QgsPointDistanceRenderer::setLabelAttributeName ( const QString & name )

inline

Sets the attribute name for labeling points.

Parameters

name	attribute name, or empty string to avoid labeling features by the renderer

See also: labelAttributeName(); setLabelFont(); setLabelColor(); setMinimumLabelScale()

Definition at line 118 of file qgspointdistancerenderer.h.

◆ setLabelColor()

void QgsPointDistanceRenderer::setLabelColor ( const QColor & color )

inline

Sets the color to use for for labeling points.

Parameters

color label color

See also: labelColor(); setLabelAttributeName(); setLabelFont()

Definition at line 170 of file qgspointdistancerenderer.h.

◆ setLabelFont()

void QgsPointDistanceRenderer::setLabelFont ( const QFont & font )

inline

Sets the font used for labeling points.

Parameters

font	label font

See also: labelFont(); setLabelAttributeName(); setLabelColor()

Definition at line 137 of file qgspointdistancerenderer.h.

◆ setLegendSymbolItem()

void QgsPointDistanceRenderer::setLegendSymbolItem	(	const QString &	key,
		QgsSymbol *	symbol
	)

overridevirtual

Sets the symbol to be used for a legend symbol item.

Parameters

key	rule key for legend symbol
symbol	new symbol for legend item. Ownership is transferred to renderer.

Since: QGIS 2.14

Reimplemented from QgsFeatureRenderer.

Definition at line 178 of file qgspointdistancerenderer.cpp.

◆ setMinimumLabelScale()

void QgsPointDistanceRenderer::setMinimumLabelScale ( double scale )

inline

Sets the minimum map scale (i.e.

most "zoomed out") at which points should be labeled by the renderer. The scale value indicates the scale denominator, e.g. 1000.0 for a 1:1000 map.

See also: minimumLabelScale(); setLabelAttributeName()

Definition at line 153 of file qgspointdistancerenderer.h.

◆ setTolerance()

void QgsPointDistanceRenderer::setTolerance ( double distance )

inline

Sets the tolerance distance for grouping points.

Units are specified using setToleranceUnit().

Parameters

distance tolerance distance

See also: tolerance(); setToleranceUnit()

Definition at line 187 of file qgspointdistancerenderer.h.

◆ setToleranceMapUnitScale()

void QgsPointDistanceRenderer::setToleranceMapUnitScale ( const QgsMapUnitScale & scale )

inline

Sets the map unit scale object for the distance tolerance.

This is only used if the toleranceUnit() is set to QgsUnitTypes::RenderMapUnits.

Parameters

scale scale for distance tolerance

See also: toleranceMapUnitScale(); setToleranceUnit()

Definition at line 221 of file qgspointdistancerenderer.h.

◆ setToleranceUnit()

void QgsPointDistanceRenderer::setToleranceUnit ( QgsUnitTypes::RenderUnit unit )

inline

Sets the units for the tolerance distance.

Parameters

unit	tolerance distance units

See also: setTolerance(); toleranceUnit()

Since: QGIS 2.12

Definition at line 204 of file qgspointdistancerenderer.h.

◆ startRender()

void QgsPointDistanceRenderer::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 321 of file qgspointdistancerenderer.cpp.

◆ stopRender()

void QgsPointDistanceRenderer::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 351 of file qgspointdistancerenderer.cpp.

◆ symbolForFeature()

QgsSymbol * QgsPointDistanceRenderer::symbolForFeature	(	const QgsFeature &	feature,
		QgsRenderContext &	context
	)		const

overridevirtual

To be overridden.

Must be called between startRender() and stopRender() calls.

Parameters

feature	feature
context	render context

Returns: returns pointer to symbol or 0 if symbol was not found

Since: QGIS 2.12

Implements QgsFeatureRenderer.

Definition at line 264 of file qgspointdistancerenderer.cpp.

◆ symbols()

QgsSymbolList QgsPointDistanceRenderer::symbols ( QgsRenderContext & context ) const

overridevirtual

Returns list of symbols used by the renderer.

Parameters

context render context

Since: QGIS 2.12

Reimplemented from QgsFeatureRenderer.

Definition at line 255 of file qgspointdistancerenderer.cpp.

◆ symbolsForFeature()

QgsSymbolList QgsPointDistanceRenderer::symbolsForFeature	(	const QgsFeature &	feature,
		QgsRenderContext &	context
	)		const

overridevirtual

Returns list of symbols used for rendering the feature.

For renderers that do not support MoreSymbolsPerFeature it is more efficient to use symbolForFeature()

Since: QGIS 2.12

Reimplemented from QgsFeatureRenderer.

Definition at line 280 of file qgspointdistancerenderer.cpp.

◆ tolerance()

double QgsPointDistanceRenderer::tolerance ( ) const

inline

Returns the tolerance distance for grouping points.

Units are retrieved using toleranceUnit().

See also: setTolerance(); toleranceUnit()

Definition at line 195 of file qgspointdistancerenderer.h.

◆ toleranceMapUnitScale()

const QgsMapUnitScale& QgsPointDistanceRenderer::toleranceMapUnitScale ( ) const

inline

Returns the map unit scale object for the distance tolerance.

This is only used if the toleranceUnit() is set to QgsUnitTypes::RenderMapUnits.

See also: setToleranceMapUnitScale(); toleranceUnit()

Definition at line 229 of file qgspointdistancerenderer.h.

◆ toleranceUnit()

QgsUnitTypes::RenderUnit QgsPointDistanceRenderer::toleranceUnit ( ) const

inline

Returns the units for the tolerance distance.

See also: tolerance(); setToleranceUnit()

Since: QGIS 2.12

Definition at line 212 of file qgspointdistancerenderer.h.

◆ toSld()

void QgsPointDistanceRenderer::toSld	(	QDomDocument &	doc,
		QDomElement &	element,
		const QVariantMap &	props = `QVariantMap()`
	)		const

overridevirtual

used from subclasses to create SLD Rule elements following SLD v1.1 specs

Reimplemented from QgsFeatureRenderer.

Definition at line 45 of file qgspointdistancerenderer.cpp.

◆ usedAttributes()

QSet< QString > QgsPointDistanceRenderer::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 227 of file qgspointdistancerenderer.cpp.

◆ willRenderFeature()

bool QgsPointDistanceRenderer::willRenderFeature	(	const QgsFeature &	feature,
		QgsRenderContext &	context
	)		const

overridevirtual

Returns whether the renderer will render a feature or not.

Must be called between startRender() and stopRender() calls. Default implementation uses symbolForFeature().

Since: QGIS 2.12

Reimplemented from QgsFeatureRenderer.

Definition at line 311 of file qgspointdistancerenderer.cpp.

Member Data Documentation

◆ mClusteredGroups

QList<ClusteredGroup> QgsPointDistanceRenderer::mClusteredGroups

protected

Groups of features that are considered clustered together.

Definition at line 259 of file qgspointdistancerenderer.h.

◆ mDrawLabels

bool QgsPointDistanceRenderer::mDrawLabels

protected

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

Definition at line 254 of file qgspointdistancerenderer.h.

◆ mGroupIndex

QMap<QgsFeatureId, int> QgsPointDistanceRenderer::mGroupIndex

protected

Mapping of feature ID to the feature's group index.

Definition at line 262 of file qgspointdistancerenderer.h.

◆ mGroupLocations

QMap<QgsFeatureId, QgsPointXY > QgsPointDistanceRenderer::mGroupLocations

protected

Mapping of feature ID to approximate group location.

Definition at line 265 of file qgspointdistancerenderer.h.

◆ mLabelAttributeName

QString QgsPointDistanceRenderer::mLabelAttributeName

protected

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

Definition at line 237 of file qgspointdistancerenderer.h.

◆ mLabelColor

QColor QgsPointDistanceRenderer::mLabelColor

protected

Label text color.

Definition at line 252 of file qgspointdistancerenderer.h.

◆ mLabelFont

QFont QgsPointDistanceRenderer::mLabelFont

protected

Label font.

Definition at line 250 of file qgspointdistancerenderer.h.

◆ mLabelIndex

int QgsPointDistanceRenderer::mLabelIndex

protected

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

Definition at line 240 of file qgspointdistancerenderer.h.

◆ mMinLabelScale

double QgsPointDistanceRenderer::mMinLabelScale = 0

protected

Maximum scale denominator for label display. A zero value indicates no scale limitation.

Definition at line 256 of file qgspointdistancerenderer.h.

◆ mRenderer

std::unique_ptr< QgsFeatureRenderer > QgsPointDistanceRenderer::mRenderer

protected

Embedded base renderer. This can be used for rendering individual, isolated points.

Definition at line 234 of file qgspointdistancerenderer.h.

◆ mSpatialIndex

QgsSpatialIndex* QgsPointDistanceRenderer::mSpatialIndex = nullptr

protected

Spatial index for fast lookup of nearby points.

Definition at line 268 of file qgspointdistancerenderer.h.

◆ mTolerance

double QgsPointDistanceRenderer::mTolerance

protected

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

Definition at line 243 of file qgspointdistancerenderer.h.

◆ mToleranceMapUnitScale

QgsMapUnitScale QgsPointDistanceRenderer::mToleranceMapUnitScale

protected

Map unit scale for distance tolerance.

Definition at line 247 of file qgspointdistancerenderer.h.

◆ mToleranceUnit

QgsUnitTypes::RenderUnit QgsPointDistanceRenderer::mToleranceUnit

protected

Unit for distance tolerance.

Definition at line 245 of file qgspointdistancerenderer.h.

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

/build/qgis-3.26.3+32focal/src/core/symbology/qgspointdistancerenderer.h
/build/qgis-3.26.3+32focal/src/core/symbology/qgspointdistancerenderer.cpp

Classes

Public Types

Public Member Functions

Protected Member Functions

Protected Attributes

Additional Inherited Members

Detailed Description

Member Typedef Documentation

◆ ClusteredGroup

Constructor & Destructor Documentation

◆ QgsPointDistanceRenderer()

Member Function Documentation

◆ accept()

◆ capabilities()

◆ checkLegendSymbolItem()

◆ drawLabels()

◆ embeddedRenderer()

◆ filter()

◆ filterNeedsGeometry()

◆ labelAttributeName()

◆ labelColor()

◆ labelFont()

◆ legendKeysForFeature()

◆ legendKeyToExpression()

◆ legendSymbolItemChecked()

◆ legendSymbolItems()

◆ legendSymbolItemsCheckable()

◆ minimumLabelScale()

◆ originalSymbolForFeature()

◆ originalSymbolsForFeature()

◆ renderFeature()

◆ setEmbeddedRenderer()

◆ setLabelAttributeName()

◆ setLabelColor()

◆ setLabelFont()

◆ setLegendSymbolItem()

◆ setMinimumLabelScale()

◆ setTolerance()

◆ setToleranceMapUnitScale()

◆ setToleranceUnit()

◆ startRender()

◆ stopRender()

◆ symbolForFeature()

◆ symbols()

◆ symbolsForFeature()

◆ tolerance()

◆ toleranceMapUnitScale()

◆ toleranceUnit()

◆ toSld()

◆ usedAttributes()

◆ willRenderFeature()

Member Data Documentation

◆ mClusteredGroups

◆ mDrawLabels

◆ mGroupIndex

◆ mGroupLocations

◆ mLabelAttributeName

◆ mLabelColor

◆ mLabelFont

◆ mLabelIndex

◆ mMinLabelScale

◆ mRenderer

◆ mSpatialIndex

◆ mTolerance

◆ mToleranceMapUnitScale

◆ mToleranceUnit