QgsAbstractVectorLayerLabeling Class Reference

Abstract base class - its implementations define different approaches to the labeling of a vector layer. More...

#include <qgsvectorlayerlabeling.h>

Inheritance diagram for QgsAbstractVectorLayerLabeling:

Public Member Functions
	QgsAbstractVectorLayerLabeling ()=default
virtual	~QgsAbstractVectorLayerLabeling ()=default
virtual bool	accept (QgsStyleEntityVisitorInterface *visitor) const
	Accepts the specified symbology visitor, causing it to visit all symbols associated with the labeling.
virtual QgsAbstractVectorLayerLabeling *	clone () const =0
	Returns a new copy of the object.
virtual void	multiplyOpacity (double opacityFactor)
	Multiply opacity by opacityFactor.
virtual QgsVectorLayerLabelProvider *	provider (QgsVectorLayer *layer) const
	Factory for label provider implementation.
virtual bool	requiresAdvancedEffects () const =0
	Returns true if drawing labels requires advanced effects like composition modes, which could prevent it being used as an isolated cached image or exported to a vector format.
virtual QDomElement	save (QDomDocument &doc, const QgsReadWriteContext &context) const =0
	Returns labeling configuration as XML element.
virtual void	setSettings (QgsPalLayerSettings *settings, const QString &providerId=QString())=0
	Set pal settings for a specific provider (takes ownership).
virtual QgsPalLayerSettings	settings (const QString &providerId=QString()) const =0
	Gets associated label settings.
virtual QStringList	subProviders () const
	Gets list of sub-providers within the layer's labeling.
virtual void	toSld (QDomNode &parent, const QVariantMap &props) const
	Writes the SE 1.1 TextSymbolizer element based on the current layer labeling settings.
virtual QString	type () const =0
	Unique type string of the labeling configuration implementation.

Static Public Member Functions
static QgsAbstractVectorLayerLabeling *	create (const QDomElement &element, const QgsReadWriteContext &context)
	Try to create instance of an implementation based on the XML data.
static QgsPalLayerSettings	defaultSettingsForLayer (const QgsVectorLayer *layer)
	Returns the default layer settings to use for the specified vector layer.

Protected Member Functions
virtual void	writeTextSymbolizer (QDomNode &parent, QgsPalLayerSettings &settings, const QVariantMap &props) const
	Writes a TextSymbolizer element contents based on the provided labeling settings.

Detailed Description

Abstract base class - its implementations define different approaches to the labeling of a vector layer.

Definition at line 40 of file qgsvectorlayerlabeling.h.

Constructor & Destructor Documentation

QgsAbstractVectorLayerLabeling()

QgsAbstractVectorLayerLabeling::QgsAbstractVectorLayerLabeling ( )

default

~QgsAbstractVectorLayerLabeling()

virtual QgsAbstractVectorLayerLabeling::~QgsAbstractVectorLayerLabeling ( )

virtualdefault

Member Function Documentation

accept()

bool QgsAbstractVectorLayerLabeling::accept ( QgsStyleEntityVisitorInterface *  visitor ) const

virtual

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

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

Since

QGIS 3.10

Reimplemented in QgsRuleBasedLabeling, and QgsVectorLayerSimpleLabeling.

Definition at line 44 of file qgsvectorlayerlabeling.cpp.

clone()

virtual QgsAbstractVectorLayerLabeling * QgsAbstractVectorLayerLabeling::clone ( ) const

pure virtual

Returns a new copy of the object.

Implemented in QgsRuleBasedLabeling, and QgsVectorLayerSimpleLabeling.

create()

QgsAbstractVectorLayerLabeling * QgsAbstractVectorLayerLabeling::create ( const QDomElement &  element, const QgsReadWriteContext &  context  )

static

Try to create instance of an implementation based on the XML data.

Definition at line 27 of file qgsvectorlayerlabeling.cpp.

defaultSettingsForLayer()

QgsPalLayerSettings QgsAbstractVectorLayerLabeling::defaultSettingsForLayer ( const QgsVectorLayer *  layer )

static

Returns the default layer settings to use for the specified vector layer.

Since

QGIS 3.20

Definition at line 49 of file qgsvectorlayerlabeling.cpp.

multiplyOpacity()

virtual void QgsAbstractVectorLayerLabeling::multiplyOpacity ( double  opacityFactor )

inlinevirtual

Multiply opacity by opacityFactor.

This method multiplies the opacity of the labeling elements (text, shadow, buffer etc.) by opacity effectively changing the opacity of the whole labeling elements.

Since

QGIS 3.32

Reimplemented in QgsRuleBasedLabeling, and QgsVectorLayerSimpleLabeling.

Definition at line 107 of file qgsvectorlayerlabeling.h.

provider()

virtual QgsVectorLayerLabelProvider * QgsAbstractVectorLayerLabeling::provider ( QgsVectorLayer *  layer ) const

inlinevirtual

Factory for label provider implementation.

Note

not available in Python bindings

Reimplemented in QgsRuleBasedLabeling, and QgsVectorLayerSimpleLabeling.

Definition at line 69 of file qgsvectorlayerlabeling.h.

requiresAdvancedEffects()

virtual bool QgsAbstractVectorLayerLabeling::requiresAdvancedEffects ( ) const

pure virtual

Returns true if drawing labels requires advanced effects like composition modes, which could prevent it being used as an isolated cached image or exported to a vector format.

Implemented in QgsRuleBasedLabeling, and QgsVectorLayerSimpleLabeling.

save()

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

pure virtual

Returns labeling configuration as XML element.

Implemented in QgsRuleBasedLabeling, and QgsVectorLayerSimpleLabeling.

setSettings()

virtual void QgsAbstractVectorLayerLabeling::setSettings ( QgsPalLayerSettings *  settings, const QString &  providerId = QString()  )

pure virtual

Set pal settings for a specific provider (takes ownership).

Parameters

settings	Pal layer settings
providerId	The id of the provider

Implemented in QgsRuleBasedLabeling, and QgsVectorLayerSimpleLabeling.

settings()

virtual QgsPalLayerSettings QgsAbstractVectorLayerLabeling::settings ( const QString &  providerId = QString() ) const

pure virtual

Gets associated label settings.

In case of multiple sub-providers with different settings, they are identified by their ID (e.g. in case of rule-based labeling, provider ID == rule key)

Implemented in QgsRuleBasedLabeling, and QgsVectorLayerSimpleLabeling.

subProviders()

virtual QStringList QgsAbstractVectorLayerLabeling::subProviders ( ) const

inlinevirtual

Gets list of sub-providers within the layer's labeling.

Reimplemented in QgsRuleBasedLabeling.

Definition at line 75 of file qgsvectorlayerlabeling.h.

toSld()

virtual void QgsAbstractVectorLayerLabeling::toSld ( QDomNode &  parent, const QVariantMap &  props  ) const

inlinevirtual

Writes the SE 1.1 TextSymbolizer element based on the current layer labeling settings.

Reimplemented in QgsRuleBasedLabeling, and QgsVectorLayerSimpleLabeling.

Definition at line 118 of file qgsvectorlayerlabeling.h.

type()

virtual QString QgsAbstractVectorLayerLabeling::type ( ) const

pure virtual

Unique type string of the labeling configuration implementation.

Implemented in QgsRuleBasedLabeling, and QgsVectorLayerSimpleLabeling.

writeTextSymbolizer()

void QgsAbstractVectorLayerLabeling::writeTextSymbolizer ( QDomNode &  parent, QgsPalLayerSettings &  settings, const QVariantMap &  props  ) const

protectedvirtual

Writes a TextSymbolizer element contents based on the provided labeling settings.

Parameters

parent	the node that will have the text symbolizer element added to it
settings	the settings getting translated to a TextSymbolizer
props	a open ended set of properties that can drive/inform the SLD encoding

Definition at line 278 of file qgsvectorlayerlabeling.cpp.

---

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

• /build/qgis-3.41.0+git20241214+cea29feecf2+99sid/src/core/labeling/qgsvectorlayerlabeling.h
• /build/qgis-3.41.0+git20241214+cea29feecf2+99sid/src/core/labeling/qgsvectorlayerlabeling.cpp