Abstract base class for all 2D vector feature renderers. More...

#include <qgsrenderer.h>

Inheritance diagram for QgsFeatureRenderer:

[legend]

Public Types
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
virtual	~QgsFeatureRenderer ()

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

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

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

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

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

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.

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

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

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

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

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

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

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

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

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

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.

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

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

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

double	referenceScale () const
	Returns the symbology reference scale.

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

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

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.

virtual void	setEmbeddedRenderer (QgsFeatureRenderer *subRenderer)
	Sets an embedded renderer (subrenderer) for this feature renderer.

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

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

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.

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

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

virtual QgsSymbol *	symbolForFeature (const QgsFeature &feature, QgsRenderContext &context) const =0
	To be overridden.

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

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

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

QString	type () const

virtual QSet< QString >	usedAttributes (const QgsRenderContext &context) const =0
	Returns a list of attributes required by this renderer.

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

bool	usingSymbolLevels () const

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

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 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.

Protected Member Functions
	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
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
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

Abstract base class for all 2D vector feature renderers.

Definition at line 105 of file qgsrenderer.h.

Member Typedef Documentation

◆ Capabilities

typedef QFlags< Capability > QgsFeatureRenderer::Capabilities

Definition at line 298 of file qgsrenderer.h.

Member Enumeration Documentation

◆ Capability

enum QgsFeatureRenderer::Capability

Used to specify details about a renderer.

Is returned from the capabilities() method.

Enumerator
SymbolLevels	Rendering with symbol levels (i.e. implements symbols(), symbolForFeature())
MoreSymbolsPerFeature	May use more than one symbol to render a feature: symbolsForFeature() will return them.
Filter	Features may be filtered, i.e. some features may not be rendered (categorized, rule based ...)
ScaleDependent	Depends on scale if feature will be rendered (rule based )

Definition at line 290 of file qgsrenderer.h.

◆ Property

enum class QgsFeatureRenderer::Property : int

strong

Data definable properties for renderers.

Since: QGIS 3.38

Enumerator
HeatmapRadius	Heatmap renderer radius.
HeatmapMaximum	Heatmap maximum value.

Definition at line 147 of file qgsrenderer.h.

Constructor & Destructor Documentation

◆ ~QgsFeatureRenderer()

QgsFeatureRenderer::~QgsFeatureRenderer ( )

virtual

Definition at line 72 of file qgsrenderer.cpp.

◆ QgsFeatureRenderer()

QgsFeatureRenderer::QgsFeatureRenderer ( const QString & type )

protected

Definition at line 65 of file qgsrenderer.cpp.

Member Function Documentation

◆ _getPoint()

QPointF QgsFeatureRenderer::_getPoint	(	QgsRenderContext &	context,
		const QgsPoint &	point
	)

staticprotected

Creates a point in screen coordinates from a wkb string in map coordinates.

Definition at line 44 of file qgsrenderer.cpp.

◆ accept()

bool QgsFeatureRenderer::accept ( QgsStyleEntityVisitorInterface * visitor ) const

virtual

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 in Qgs25DRenderer, QgsCategorizedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsHeatmapRenderer, QgsMergedFeatureRenderer, QgsPointClusterRenderer, QgsPointDisplacementRenderer, QgsPointDistanceRenderer, QgsRuleBasedRenderer, and QgsSingleSymbolRenderer.

Definition at line 553 of file qgsrenderer.cpp.

◆ canSkipRender()

bool QgsFeatureRenderer::canSkipRender ( )

virtual

Returns true if the renderer can be entirely skipped, i.e.

if it is known in advance that no features will be rendered.

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

Since: QGIS 3.30

Reimplemented in QgsRuleBasedRenderer.

Definition at line 116 of file qgsrenderer.cpp.

◆ capabilities()

virtual QgsFeatureRenderer::Capabilities QgsFeatureRenderer::capabilities ( )

inlinevirtual

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 in QgsCategorizedSymbolRenderer, QgsEmbeddedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsMergedFeatureRenderer, QgsPointDistanceRenderer, QgsRuleBasedRenderer, and QgsSingleSymbolRenderer.

Definition at line 312 of file qgsrenderer.h.

◆ checkLegendSymbolItem()

void QgsFeatureRenderer::checkLegendSymbolItem	(	const QString &	key,
		bool	state = `true`
	)

virtual

Sets whether the legend symbology item with the specified ley should be checked.

See also: legendSymbolItemChecked(); legendKeys()

Reimplemented in QgsPointDistanceRenderer, QgsCategorizedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsMergedFeatureRenderer, and QgsRuleBasedRenderer.

Definition at line 397 of file qgsrenderer.cpp.

◆ clone()

virtual QgsFeatureRenderer * QgsFeatureRenderer::clone ( ) const

pure virtual

Create a deep copy of this renderer.

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

Returns: A copy of this renderer

Implemented in Qgs25DRenderer, QgsCategorizedSymbolRenderer, QgsEmbeddedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsHeatmapRenderer, QgsInvertedPolygonRenderer, QgsMergedFeatureRenderer, QgsNullSymbolRenderer, QgsPointClusterRenderer, QgsPointDisplacementRenderer, QgsRuleBasedRenderer, and QgsSingleSymbolRenderer.

◆ convertSymbolRotation()

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

staticprotected

Note: this function is used to convert old rotations expressions to symbol level DataDefined angle

Definition at line 580 of file qgsrenderer.cpp.

◆ convertSymbolSizeScale()

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

staticprotected

Note: this function is used to convert old sizeScale expressions to symbol level DataDefined size

Definition at line 558 of file qgsrenderer.cpp.

◆ copyRendererData()

void QgsFeatureRenderer::copyRendererData ( QgsFeatureRenderer * destRenderer ) const

Clones generic renderer data to another renderer.

Currently clones

Order by
Paint effect
Reference scale
Symbol levels enabled/disabled
Force raster render enabled/disabled
Data defined properties

Parameters

destRenderer destination renderer for copied effect

Since: QGIS 3.22

Definition at line 49 of file qgsrenderer.cpp.

◆ createLegendNodes()

QList< QgsLayerTreeModelLegendNode * > QgsFeatureRenderer::createLegendNodes ( QgsLayerTreeLayer * nodeLayer ) const

virtual

Returns a list of legend nodes to be used for the legend for the renderer.

Ownership is transferred to the caller.

The default implementation creates a legend node for each symbol item returned by legendSymbolItems()

See also: legendSymbolItems()

Since: QGIS 3.38

Reimplemented in QgsHeatmapRenderer.

Definition at line 420 of file qgsrenderer.cpp.

◆ dataDefinedProperties() [1/2]

QgsPropertyCollection & QgsFeatureRenderer::dataDefinedProperties ( )

inline

Returns a reference to the renderer's property collection, used for data defined overrides.

See also: setDataDefinedProperties(); Property

Since: QGIS 3.38

Definition at line 530 of file qgsrenderer.h.

◆ dataDefinedProperties() [2/2]

const QgsPropertyCollection & QgsFeatureRenderer::dataDefinedProperties ( ) const

inline

Returns a reference to the renderer's property collection, used for data defined overrides.

See also: setDataDefinedProperties()

Since: QGIS 3.38

Definition at line 539 of file qgsrenderer.h.

◆ defaultRenderer()

QgsFeatureRenderer * QgsFeatureRenderer::defaultRenderer ( Qgis::GeometryType geomType )

static

Returns a new renderer - used by default in vector layers.

Definition at line 83 of file qgsrenderer.cpp.

◆ dump()

QString QgsFeatureRenderer::dump ( ) const

virtual

Returns debug information about this renderer.

Reimplemented in QgsCategorizedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsHeatmapRenderer, QgsInvertedPolygonRenderer, QgsMergedFeatureRenderer, QgsNullSymbolRenderer, QgsRuleBasedRenderer, and QgsSingleSymbolRenderer.

Definition at line 157 of file qgsrenderer.cpp.

◆ embeddedRenderer()

const QgsFeatureRenderer * QgsFeatureRenderer::embeddedRenderer ( ) const

virtual

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()

Reimplemented in QgsMergedFeatureRenderer, and QgsPointDistanceRenderer.

Definition at line 548 of file qgsrenderer.cpp.

◆ filter()

virtual QString QgsFeatureRenderer::filter ( const QgsFields & fields = QgsFields() )

inlinevirtual

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 in QgsCategorizedSymbolRenderer, QgsPointDistanceRenderer, and QgsRuleBasedRenderer.

Definition at line 235 of file qgsrenderer.h.

◆ filterNeedsGeometry()

bool QgsFeatureRenderer::filterNeedsGeometry ( ) const

virtual

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

Reimplemented in QgsCategorizedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsMergedFeatureRenderer, QgsPointDistanceRenderer, and QgsRuleBasedRenderer.

Definition at line 133 of file qgsrenderer.cpp.

◆ flags()

Qgis::FeatureRendererFlags QgsFeatureRenderer::flags ( ) const

virtual

Returns flags associated with the renderer.

Since: QGIS 3.40

Reimplemented in Qgs25DRenderer, QgsCategorizedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsMergedFeatureRenderer, QgsPointClusterRenderer, QgsPointDisplacementRenderer, QgsRuleBasedRenderer, and QgsSingleSymbolRenderer.

Definition at line 162 of file qgsrenderer.cpp.

◆ forceRasterRender()

bool QgsFeatureRenderer::forceRasterRender ( ) const

inline

Returns whether the renderer must render as a raster.

See also: setForceRasterRender

Definition at line 500 of file qgsrenderer.h.

◆ legendClassificationAttribute()

virtual QString QgsFeatureRenderer::legendClassificationAttribute ( ) const

inlinevirtual

If supported by the renderer, return classification attribute for the use in legend.

Reimplemented in QgsCategorizedSymbolRenderer, and QgsGraduatedSymbolRenderer.

Definition at line 449 of file qgsrenderer.h.

◆ legendKeys()

QSet< QString > QgsFeatureRenderer::legendKeys ( ) const

Returns the set of all legend keys used by the renderer.

See also: legendSymbolItems()

Since: QGIS 3.32

Definition at line 358 of file qgsrenderer.cpp.

◆ legendKeysForFeature()

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

virtual

Returns legend keys matching a specified feature.

Reimplemented in QgsCategorizedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsMergedFeatureRenderer, QgsPointDistanceRenderer, QgsRuleBasedRenderer, and QgsSingleSymbolRenderer.

Definition at line 93 of file qgsrenderer.cpp.

◆ legendKeyToExpression()

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

virtual

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

See also: legendKeys()

Since: QGIS 3.26

Reimplemented in QgsCategorizedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsMergedFeatureRenderer, QgsPointDistanceRenderer, QgsRuleBasedRenderer, and QgsSingleSymbolRenderer.

Definition at line 409 of file qgsrenderer.cpp.

◆ legendSymbolItemChecked()

bool QgsFeatureRenderer::legendSymbolItemChecked ( const QString & key )

virtual

Returns true if the legend symbology item with the specified key is checked.

See also: checkLegendSymbolItem(); legendKeys()

Reimplemented in QgsCategorizedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsMergedFeatureRenderer, QgsPointDistanceRenderer, and QgsRuleBasedRenderer.

Definition at line 391 of file qgsrenderer.cpp.

◆ legendSymbolItems()

QgsLegendSymbolList QgsFeatureRenderer::legendSymbolItems ( ) const

virtual

Returns a list of symbology items for the legend.

See also: createLegendNodes(); legendKeys()

Reimplemented in QgsCategorizedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsMergedFeatureRenderer, QgsPointDistanceRenderer, QgsRuleBasedRenderer, and QgsSingleSymbolRenderer.

Definition at line 415 of file qgsrenderer.cpp.

◆ legendSymbolItemsCheckable()

bool QgsFeatureRenderer::legendSymbolItemsCheckable ( ) const

virtual

Returns true if symbology items in legend are checkable.

Reimplemented in QgsCategorizedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsMergedFeatureRenderer, QgsPointDistanceRenderer, and QgsRuleBasedRenderer.

Definition at line 386 of file qgsrenderer.cpp.

◆ load()

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

static

create a renderer from XML element

Definition at line 173 of file qgsrenderer.cpp.

◆ loadSld()

QgsFeatureRenderer * QgsFeatureRenderer::loadSld	(	const QDomNode &	node,
		Qgis::GeometryType	geomType,
		QString &	errorMessage
	)

static

Create a new renderer according to the information contained in the UserStyle element of a SLD style document.

Parameters

node	the node in the SLD document whose the UserStyle element is a child
geomType	the geometry type of the features, used to convert Symbolizer elements
errorMessage	it will contain the error message if something went wrong

Returns: the renderer

Definition at line 246 of file qgsrenderer.cpp.

◆ modifyRequestExtent()

void QgsFeatureRenderer::modifyRequestExtent	(	QgsRectangle &	extent,
		QgsRenderContext &	context
	)

virtual

Allows for a renderer to modify the extent of a feature request prior to rendering.

Parameters

extent	reference to request's filter extent. Modify extent to change the extent of feature request
context	render context

Reimplemented in QgsHeatmapRenderer.

Definition at line 493 of file qgsrenderer.cpp.

◆ orderBy()

QgsFeatureRequest::OrderBy QgsFeatureRenderer::orderBy ( ) const

Gets the order in which features shall be processed by this renderer.

Note: this property has no effect if orderByEnabled() is false

See also: orderByEnabled()

Definition at line 523 of file qgsrenderer.cpp.

◆ orderByEnabled()

bool QgsFeatureRenderer::orderByEnabled ( ) const

Returns whether custom ordering will be applied before features are processed by this renderer.

See also: orderBy(); setOrderByEnabled()

Definition at line 533 of file qgsrenderer.cpp.

◆ originalSymbolForFeature()

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

virtual

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.

Reimplemented in QgsCategorizedSymbolRenderer, QgsEmbeddedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsMergedFeatureRenderer, QgsNullSymbolRenderer, QgsPointDistanceRenderer, and QgsSingleSymbolRenderer.

Definition at line 88 of file qgsrenderer.cpp.

◆ originalSymbolsForFeature()

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

virtual

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

Reimplemented in QgsMergedFeatureRenderer, QgsPointDistanceRenderer, and QgsRuleBasedRenderer.

Definition at line 499 of file qgsrenderer.cpp.

◆ paintEffect()

QgsPaintEffect * QgsFeatureRenderer::paintEffect ( ) const

Returns the current paint effect for the renderer.

Returns: paint effect

See also: setPaintEffect

Definition at line 507 of file qgsrenderer.cpp.

◆ propertyDefinitions()

const QgsPropertiesDefinition & QgsFeatureRenderer::propertyDefinitions ( )

static

Returns the symbol property definitions.

Since: QGIS 3.18

Definition at line 77 of file qgsrenderer.cpp.

◆ referenceScale()

double QgsFeatureRenderer::referenceScale ( ) const

inline

Returns the symbology reference scale.

This represents the desired scale denominator for the rendered map, eg 1000.0 for a 1:1000 map render. A value of -1 indicates that symbology scaling by reference scale is disabled.

The symbology reference scale is an optional property which specifies the reference scale at which symbology in paper units (such a millimeters or points) is fixed to. For instance, if the scale is 1000 then a 2mm thick line will be rendered at exactly 2mm thick when a map is rendered at 1:1000, or 1mm thick when rendered at 1:2000, or 4mm thick at 1:500.

See also: setReferenceScale()

Since: QGIS 3.22

Definition at line 566 of file qgsrenderer.h.

◆ renderFeature()

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

virtual

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 in QgsEmbeddedSymbolRenderer, QgsHeatmapRenderer, QgsMergedFeatureRenderer, QgsNullSymbolRenderer, QgsPointDistanceRenderer, and QgsRuleBasedRenderer.

Definition at line 138 of file qgsrenderer.cpp.

◆ renderFeatureWithSymbol()

void QgsFeatureRenderer::renderFeatureWithSymbol	(	const QgsFeature &	feature,
		QgsSymbol *	symbol,
		QgsRenderContext &	context,
		int	layer,
		bool	selected,
		bool	drawVertexMarker
	)

protected

Render the feature with the symbol using context.

Use layer to specify the symbol layer, selected to specify if it should be rendered as selected and drawVertexMarker to specify if vertex markers should be rendered.

Definition at line 152 of file qgsrenderer.cpp.

◆ renderVertexMarker()

void QgsFeatureRenderer::renderVertexMarker	(	QPointF	pt,
		QgsRenderContext &	context
	)

protected

render editing vertex marker at specified point

Definition at line 452 of file qgsrenderer.cpp.

◆ renderVertexMarkerPolygon()

void QgsFeatureRenderer::renderVertexMarkerPolygon	(	QPolygonF &	pts,
		QList< QPolygonF > *	rings,
		QgsRenderContext &	context
	)

protected

render editing vertex marker for a polygon

Definition at line 467 of file qgsrenderer.cpp.

◆ renderVertexMarkerPolyline()

void QgsFeatureRenderer::renderVertexMarkerPolyline	(	QPolygonF &	pts,
		QgsRenderContext &	context
	)

protected

render editing vertex marker for a polyline

Definition at line 460 of file qgsrenderer.cpp.

◆ save()

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

virtual

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 in Qgs25DRenderer, QgsCategorizedSymbolRenderer, QgsEmbeddedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsHeatmapRenderer, QgsInvertedPolygonRenderer, QgsMergedFeatureRenderer, QgsNullSymbolRenderer, QgsPointClusterRenderer, QgsPointDisplacementRenderer, QgsRuleBasedRenderer, and QgsSingleSymbolRenderer.

Definition at line 213 of file qgsrenderer.cpp.

◆ saveRendererData()

void QgsFeatureRenderer::saveRendererData	(	QDomDocument &	doc,
		QDomElement &	element,
		const QgsReadWriteContext &	context
	)

protected

Saves generic renderer data into the specified element.

This method should be called in a subclass' save() implementation in order to store all common base class properties in the DOM element.

Since: QGIS 3.22

Definition at line 224 of file qgsrenderer.cpp.

◆ setDataDefinedProperties()

void QgsFeatureRenderer::setDataDefinedProperties ( const QgsPropertyCollection & collection )

inline

Sets the renderer's property collection, used for data defined overrides.

Parameters

collection property collection. Existing properties will be replaced.

See also: dataDefinedProperties()

Since: QGIS 3.38

Definition at line 550 of file qgsrenderer.h.

◆ setDataDefinedProperty()

void QgsFeatureRenderer::setDataDefinedProperty	(	Property	key,
		const QgsProperty &	property
	)

Sets a data defined property for the renderer.

Any existing property with the same key will be overwritten.

See also: dataDefinedProperties(); Property

Since: QGIS 3.38

Definition at line 518 of file qgsrenderer.cpp.

◆ setEmbeddedRenderer()

void QgsFeatureRenderer::setEmbeddedRenderer ( QgsFeatureRenderer * subRenderer )

virtual

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()

Reimplemented in QgsPointDistanceRenderer, and QgsMergedFeatureRenderer.

Definition at line 543 of file qgsrenderer.cpp.

◆ setForceRasterRender()

void QgsFeatureRenderer::setForceRasterRender ( bool forceRaster )

inline

Sets whether the renderer should be rendered to a raster destination.

Parameters

forceRaster set to true if renderer must be drawn on a raster surface. This may be desirable for highly detailed layers where rendering as a vector would result in a large, complex vector output.

See also: forceRasterRender

Definition at line 509 of file qgsrenderer.h.

◆ setLegendSymbolItem()

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

virtual

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.

See also: legendKeys()

Reimplemented in QgsCategorizedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsMergedFeatureRenderer, QgsPointDistanceRenderer, QgsRuleBasedRenderer, and QgsSingleSymbolRenderer.

Definition at line 403 of file qgsrenderer.cpp.

◆ setOrderBy()

void QgsFeatureRenderer::setOrderBy ( const QgsFeatureRequest::OrderBy & orderBy )

Define the order in which features shall be processed by this renderer.

Note: this property has no effect if orderByEnabled() is false

See also: setOrderByEnabled()

Definition at line 528 of file qgsrenderer.cpp.

◆ setOrderByEnabled()

void QgsFeatureRenderer::setOrderByEnabled ( bool enabled )

Sets whether custom ordering should be applied before features are processed by this renderer.

Parameters

enabled set to true to enable custom feature ordering

See also: setOrderBy(); orderByEnabled()

Definition at line 538 of file qgsrenderer.cpp.

◆ setPaintEffect()

void QgsFeatureRenderer::setPaintEffect ( QgsPaintEffect * effect )

Sets the current paint effect for the renderer.

Parameters

effect paint effect. Ownership is transferred to the renderer.

See also: paintEffect

Definition at line 512 of file qgsrenderer.cpp.

◆ setReferenceScale()

void QgsFeatureRenderer::setReferenceScale ( double scale )

inline

Sets the symbology reference scale.

This should match the desired scale denominator for the rendered map, eg 1000.0 for a 1:1000 map render. Set to -1 to disable symbology scaling by reference scale.

The symbology reference scale is an optional property which specifies the reference scale at which symbology in paper units (such a millimeters or points) is fixed to. For instance, if scale is set to 1000 then a 2mm thick line will be rendered at exactly 2mm thick when a map is rendered at 1:1000, or 1mm thick when rendered at 1:2000, or 4mm thick at 1:500.

See also: referenceScale()

Since: QGIS 3.22

Definition at line 582 of file qgsrenderer.h.

◆ setUsingSymbolLevels()

void QgsFeatureRenderer::setUsingSymbolLevels ( bool usingSymbolLevels )

inline

Definition at line 328 of file qgsrenderer.h.

◆ setVertexMarkerAppearance()

void QgsFeatureRenderer::setVertexMarkerAppearance	(	Qgis::VertexMarkerType	type,
		double	size
	)

Sets type and size of editing vertex markers for subsequent rendering.

Definition at line 441 of file qgsrenderer.cpp.

◆ startRender()

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

virtual

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 in Qgs25DRenderer, QgsCategorizedSymbolRenderer, QgsEmbeddedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsHeatmapRenderer, QgsMergedFeatureRenderer, QgsPointClusterRenderer, QgsPointDisplacementRenderer, QgsPointDistanceRenderer, QgsRuleBasedRenderer, and QgsSingleSymbolRenderer.

Definition at line 100 of file qgsrenderer.cpp.

◆ stopRender()

void QgsFeatureRenderer::stopRender ( QgsRenderContext & context )

virtual

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 in Qgs25DRenderer, QgsCategorizedSymbolRenderer, QgsEmbeddedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsHeatmapRenderer, QgsMergedFeatureRenderer, QgsNullSymbolRenderer, QgsPointClusterRenderer, QgsPointDisplacementRenderer, QgsPointDistanceRenderer, QgsRuleBasedRenderer, and QgsSingleSymbolRenderer.

Definition at line 121 of file qgsrenderer.cpp.

◆ symbolForFeature()

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

pure virtual

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

Implemented in Qgs25DRenderer, QgsCategorizedSymbolRenderer, QgsEmbeddedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsHeatmapRenderer, QgsMergedFeatureRenderer, QgsNullSymbolRenderer, QgsPointDistanceRenderer, QgsRuleBasedRenderer, and QgsSingleSymbolRenderer.

◆ symbols()

QgsSymbolList QgsFeatureRenderer::symbols ( QgsRenderContext & context ) const

virtual

Returns list of symbols used by the renderer.

Parameters

context render context

Reimplemented in Qgs25DRenderer, QgsCategorizedSymbolRenderer, QgsEmbeddedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsHeatmapRenderer, QgsMergedFeatureRenderer, QgsNullSymbolRenderer, QgsPointDistanceRenderer, QgsRuleBasedRenderer, and QgsSingleSymbolRenderer.

Definition at line 167 of file qgsrenderer.cpp.

◆ symbolsForFeature()

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

virtual

Returns list of symbols used for rendering the feature.

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

Reimplemented in QgsMergedFeatureRenderer, QgsPointDistanceRenderer, and QgsRuleBasedRenderer.

Definition at line 485 of file qgsrenderer.cpp.

◆ toSld()

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

inlinevirtual

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

Reimplemented in QgsCategorizedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsPointDistanceRenderer, QgsRuleBasedRenderer, and QgsSingleSymbolRenderer.

Definition at line 360 of file qgsrenderer.h.

◆ type()

QString QgsFeatureRenderer::type ( ) const

inline

Definition at line 164 of file qgsrenderer.h.

◆ usedAttributes()

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

pure virtual

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

Implemented in Qgs25DRenderer, QgsCategorizedSymbolRenderer, QgsEmbeddedSymbolRenderer, QgsGraduatedSymbolRenderer, QgsHeatmapRenderer, QgsMergedFeatureRenderer, QgsNullSymbolRenderer, QgsPointClusterRenderer, QgsPointDisplacementRenderer, QgsPointDistanceRenderer, QgsRuleBasedRenderer, and QgsSingleSymbolRenderer.

◆ usesEmbeddedSymbols()

bool QgsFeatureRenderer::usesEmbeddedSymbols ( ) const

virtual

Returns true if the renderer uses embedded symbols for features.

The default implementation returns false.

Since: QGIS 3.20

Reimplemented in QgsEmbeddedSymbolRenderer.

Definition at line 128 of file qgsrenderer.cpp.

◆ usingSymbolLevels()

bool QgsFeatureRenderer::usingSymbolLevels ( ) const

inline

Definition at line 327 of file qgsrenderer.h.

◆ willRenderFeature()

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

virtual

Returns whether the renderer will render a feature or not.

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

Reimplemented in QgsMergedFeatureRenderer, QgsNullSymbolRenderer, QgsPointDistanceRenderer, and QgsRuleBasedRenderer.

Definition at line 447 of file qgsrenderer.cpp.

◆ writeSld()

QDomElement QgsFeatureRenderer::writeSld	(	QDomDocument &	doc,
		const QString &	styleName,
		const QVariantMap &	props = `QVariantMap()`
	)		const

virtual

create the SLD UserStyle element following the SLD v1.1 specs with the given name

Definition at line 371 of file qgsrenderer.cpp.

Member Data Documentation

◆ mCurrentVertexMarkerSize

double QgsFeatureRenderer::mCurrentVertexMarkerSize = 2

protected

The current size of editing marker.

Definition at line 698 of file qgsrenderer.h.

◆ mCurrentVertexMarkerType

Qgis::VertexMarkerType QgsFeatureRenderer::mCurrentVertexMarkerType = Qgis::VertexMarkerType::Cross

protected

The current type of editing marker.

Definition at line 695 of file qgsrenderer.h.

◆ mForceRaster

bool QgsFeatureRenderer::mForceRaster = false

protected

Definition at line 702 of file qgsrenderer.h.

◆ mOrderBy

QgsFeatureRequest::OrderBy QgsFeatureRenderer::mOrderBy

protected

Definition at line 718 of file qgsrenderer.h.

◆ mOrderByEnabled

bool QgsFeatureRenderer::mOrderByEnabled = false

protected

Definition at line 720 of file qgsrenderer.h.

◆ mPaintEffect

QgsPaintEffect* QgsFeatureRenderer::mPaintEffect = nullptr

protected

Definition at line 700 of file qgsrenderer.h.

◆ mReferenceScale

double QgsFeatureRenderer::mReferenceScale = -1.0

protected

Definition at line 704 of file qgsrenderer.h.

◆ mType

QString QgsFeatureRenderer::mType

protected

Definition at line 690 of file qgsrenderer.h.

◆ mUsingSymbolLevels

bool QgsFeatureRenderer::mUsingSymbolLevels = false

protected

Definition at line 692 of file qgsrenderer.h.

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

/build/qgis-3.41.0+git20241116+25ec5511245+99sid/src/core/symbology/qgsrenderer.h
/build/qgis-3.41.0+git20241116+25ec5511245+99sid/src/core/symbology/qgsrenderer.cpp

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Static Protected Member Functions

Protected Attributes

Detailed Description

Member Typedef Documentation

◆ Capabilities

Member Enumeration Documentation

◆ Capability

◆ Property

Constructor & Destructor Documentation

◆ ~QgsFeatureRenderer()

◆ QgsFeatureRenderer()

Member Function Documentation

◆ _getPoint()

◆ accept()

◆ canSkipRender()

◆ capabilities()

◆ checkLegendSymbolItem()

◆ clone()

◆ convertSymbolRotation()

◆ convertSymbolSizeScale()

◆ copyRendererData()

◆ createLegendNodes()

◆ dataDefinedProperties() [1/2]

◆ dataDefinedProperties() [2/2]

◆ defaultRenderer()

◆ dump()

◆ embeddedRenderer()

◆ filter()

◆ filterNeedsGeometry()

◆ flags()

◆ forceRasterRender()

◆ legendClassificationAttribute()

◆ legendKeys()

◆ legendKeysForFeature()

◆ legendKeyToExpression()

◆ legendSymbolItemChecked()

◆ legendSymbolItems()

◆ legendSymbolItemsCheckable()

◆ load()

◆ loadSld()

◆ modifyRequestExtent()

◆ orderBy()

◆ orderByEnabled()

◆ originalSymbolForFeature()

◆ originalSymbolsForFeature()

◆ paintEffect()

◆ propertyDefinitions()

◆ referenceScale()

◆ renderFeature()

◆ renderFeatureWithSymbol()

◆ renderVertexMarker()

◆ renderVertexMarkerPolygon()

◆ renderVertexMarkerPolyline()

◆ save()

◆ saveRendererData()

◆ setDataDefinedProperties()

◆ setDataDefinedProperty()

◆ setEmbeddedRenderer()

◆ setForceRasterRender()

◆ setLegendSymbolItem()

◆ setOrderBy()

◆ setOrderByEnabled()

◆ setPaintEffect()

◆ setReferenceScale()

◆ setUsingSymbolLevels()

◆ setVertexMarkerAppearance()

◆ startRender()

◆ stopRender()

◆ symbolForFeature()

◆ symbols()

◆ symbolsForFeature()

◆ toSld()

◆ type()

◆ usedAttributes()

◆ usesEmbeddedSymbols()

◆ usingSymbolLevels()