Implementation class for QgsVectorTileBasicLabeling. More...

#include <qgsvectortilebasiclabeling.h>

Inheritance diagram for QgsVectorTileBasicLabelProvider:

Public Member Functions
	QgsVectorTileBasicLabelProvider (QgsVectorTileLayer *layer, const QList< QgsVectorTileBasicLabelingStyle > &styles)
	Constructs a label provider for the given vector tile layer and using styling from QgsVectorTileBasicLabeling.

bool	prepare (QgsRenderContext &context, QSet< QString > &attributeNames) override
	Prepare for registration of features.

void	registerTileFeatures (const QgsVectorTileRendererData &tile, QgsRenderContext &context) override
	Registers label features for given tile to the labeling engine.

QSet< QString >	requiredLayers (QgsRenderContext &context, int tileZoom) const override
	Returns a list of the layers required for labeling.

void	setFields (const QMap< QString, QgsFields > &perLayerFields) override
	Sets fields for each sub-layer.

QList< QgsAbstractLabelProvider * >	subProviders () override
	Returns list of child providers - useful if the provider needs to put labels into more layers with different configuration.

QMap< QString, QSet< QString > >	usedAttributes (const QgsRenderContext &context, int tileZoom) const override
	Returns field names for each sub-layer that are required for labeling.

Public Member Functions inherited from QgsVectorTileLabelProvider
	QgsVectorTileLabelProvider (QgsVectorTileLayer *layer)
	Constructs base label provider class for the given vector tile layer.

Public Member Functions inherited from QgsVectorLayerLabelProvider
	QgsVectorLayerLabelProvider (Qgis::GeometryType geometryType, const QgsFields &fields, const QgsCoordinateReferenceSystem &crs, const QString &providerId, const QgsPalLayerSettings settings, QgsMapLayer layer, const QString &layerName=QString())
	Constructor to initialize the provider from any map layer (e.g. vector tile layer)

	QgsVectorLayerLabelProvider (QgsVectorLayer layer, const QString &providerId, bool withFeatureLoop, const QgsPalLayerSettings settings, const QString &layerName=QString())
	Convenience constructor to initialize the provider from given vector layer.

	~QgsVectorLayerLabelProvider () override

void	drawLabel (QgsRenderContext &context, pal::LabelPosition *label) const override
	Draw this label at the position determined by the labeling engine.

void	drawLabelBackground (QgsRenderContext &context, pal::LabelPosition *label) const override
	Draw the background for the specified label.

void	drawUnplacedLabel (QgsRenderContext &context, pal::LabelPosition *label) const override
	Draw an unplaced label.

QList< QgsLabelFeature * >	labelFeatures (QgsRenderContext &context) override
	Returns list of label features (they are owned by the provider and thus deleted on its destruction)

virtual QList< QgsLabelFeature * >	registerFeature (const QgsFeature &feature, QgsRenderContext &context, const QgsGeometry &obstacleGeometry=QgsGeometry(), const QgsSymbol *symbol=nullptr)
	Register a feature for labeling as one or more QgsLabelFeature objects stored into mLabels.

void	setFields (const QgsFields &fields)
	Sets fields of this label provider.

const QgsPalLayerSettings &	settings () const
	Returns the layer's settings.

void	startRender (QgsRenderContext &context) override
	To be called before rendering of labels begins.

void	stopRender (QgsRenderContext &context) override
	To be called after rendering is complete.

Public Member Functions inherited from QgsAbstractLabelProvider
	QgsAbstractLabelProvider (QgsMapLayer *layer, const QString &providerId=QString())
	Construct the provider with default values.

virtual	~QgsAbstractLabelProvider ()=default

Flags	flags () const
	Flags associated with the provider.

QgsMapLayer *	layer () const
	Returns the associated layer, or `nullptr` if no layer is associated with the provider.

QgsExpressionContextScope *	layerExpressionContextScope () const
	Returns the expression context scope created from the layer associated with this provider.

QString	layerId () const
	Returns ID of associated layer, or empty string if no layer is associated with the provider.

double	layerReferenceScale () const
	Returns the symbology reference scale of the layer associated with this provider.

QString	name () const
	Name of the layer (for statistics, debugging etc.) - does not need to be unique.

QgsLabelObstacleSettings::ObstacleType	obstacleType () const
	How the feature geometries will work as obstacles.

Qgis::LabelPlacement	placement () const
	What placement strategy to use for the labels.

double	priority () const
	Default priority of labels (may be overridden by individual labels)

QString	providerId () const
	Returns provider ID - useful in case there is more than one label provider within a layer (e.g.

void	setEngine (const QgsLabelingEngine *engine)
	Associate provider with a labeling engine (should be only called internally from QgsLabelingEngine)

Qgis::UpsideDownLabelHandling	upsidedownLabels () const
	How to handle labels that would be upside down.

Public Attributes
QMap< QString, QgsFields >	mPerLayerFields
	Names of required fields for each sub-layer (only valid between startRender/stopRender calls)

Additional Inherited Members
Public Types inherited from QgsAbstractLabelProvider
enum	Flag { DrawLabels = 1 << 1 , MergeConnectedLines = 1 << 3 , CentroidMustBeInside = 1 << 4 }

Static Public Member Functions inherited from QgsVectorLayerLabelProvider
static QgsGeometry	getPointObstacleGeometry (QgsFeature &fet, QgsRenderContext &context, const QgsSymbolList &symbols)
	Returns the geometry for a point feature which should be used as an obstacle for labels.

Protected Member Functions inherited from QgsVectorLayerLabelProvider
void	drawLabelPrivate (pal::LabelPosition *label, QgsRenderContext &context, QgsPalLayerSettings &tmpLyr, Qgis::TextComponent drawType, double dpiRatio=1.0) const
	Internal label drawing method.

void	init ()
	initialization method - called from constructors

Protected Attributes inherited from QgsVectorLayerLabelProvider
QgsCoordinateReferenceSystem	mCrs
	Layer's CRS.

QgsFields	mFields
	Layer's fields.

QList< QgsLabelFeature * >	mLabels
	List of generated.

Qgis::GeometryType	mLayerGeometryType
	Geometry type of layer.

QgsFeatureRenderer *	mRenderer = nullptr

QgsPalLayerSettings	mSettings
	Layer's labeling configuration.

std::unique_ptr< QgsAbstractFeatureSource >	mSource
	Layer's feature source.

Protected Attributes inherited from QgsAbstractLabelProvider
const QgsLabelingEngine *	mEngine = nullptr
	Associated labeling engine.

Flags	mFlags = DrawLabels
	Flags altering drawing and registration of features.

QgsWeakMapLayerPointer	mLayer
	Weak pointer to source layer.

QString	mLayerId
	Associated layer's ID, if applicable.

QString	mName
	Name of the layer.

QgsLabelObstacleSettings::ObstacleType	mObstacleType = QgsLabelObstacleSettings::PolygonBoundary
	Type of the obstacle of feature geometries.

Qgis::LabelPlacement	mPlacement = Qgis::LabelPlacement::AroundPoint
	Placement strategy.

double	mPriority = 0.5
	Default priority of labels.

QString	mProviderId
	Associated provider ID (one layer may have multiple providers, e.g. in rule-based labeling)

Qgis::UpsideDownLabelHandling	mUpsidedownLabels = Qgis::UpsideDownLabelHandling::FlipUpsideDownLabels
	How to handle labels that would be upside down.

Detailed Description

Implementation class for QgsVectorTileBasicLabeling.

Since: QGIS 3.14

Definition at line 184 of file qgsvectortilebasiclabeling.h.

Constructor & Destructor Documentation

◆ QgsVectorTileBasicLabelProvider()

QgsVectorTileBasicLabelProvider::QgsVectorTileBasicLabelProvider	(	QgsVectorTileLayer *	layer,
		const QList< QgsVectorTileBasicLabelingStyle > &	styles
	)

Constructs a label provider for the given vector tile layer and using styling from QgsVectorTileBasicLabeling.

Definition at line 111 of file qgsvectortilebasiclabeling.cpp.

Member Function Documentation

◆ prepare()

bool QgsVectorTileBasicLabelProvider::prepare	(	QgsRenderContext &	context,
		QSet< QString > &	attributeNames
	)

overridevirtual

Prepare for registration of features.

Must be called after provider has been added to engine (uses its map settings)

Parameters

context	render context.
attributeNames	list of attribute names to which additional required attributes shall be added

Returns: Whether the preparation was successful - if not, the provider shall not be used

Reimplemented from QgsVectorLayerLabelProvider.

Definition at line 174 of file qgsvectortilebasiclabeling.cpp.

◆ registerTileFeatures()

void QgsVectorTileBasicLabelProvider::registerTileFeatures	(	const QgsVectorTileRendererData &	tile,
		QgsRenderContext &	context
	)

overridevirtual

Registers label features for given tile to the labeling engine.

Implements QgsVectorTileLabelProvider.

Definition at line 200 of file qgsvectortilebasiclabeling.cpp.

◆ requiredLayers()

QSet< QString > QgsVectorTileBasicLabelProvider::requiredLayers	(	QgsRenderContext &	context,
		int	tileZoom
	)		const

overridevirtual

Returns a list of the layers required for labeling.

Only layers which are labeled at the specified tileZoom should be included in this list.

An empty string present in the list indicates that all layer in the tiles are required.

Since: QGIS 3.16

Reimplemented from QgsVectorTileLabelProvider.

Definition at line 145 of file qgsvectortilebasiclabeling.cpp.

◆ setFields()

void QgsVectorTileBasicLabelProvider::setFields ( const QMap< QString, QgsFields > & perLayerFields )

overridevirtual

Sets fields for each sub-layer.

Implements QgsVectorTileLabelProvider.

Definition at line 158 of file qgsvectortilebasiclabeling.cpp.

◆ subProviders()

QList< QgsAbstractLabelProvider * > QgsVectorTileBasicLabelProvider::subProviders ( )

overridevirtual

Returns list of child providers - useful if the provider needs to put labels into more layers with different configuration.

Reimplemented from QgsAbstractLabelProvider.

Definition at line 163 of file qgsvectortilebasiclabeling.cpp.

◆ usedAttributes()

QMap< QString, QSet< QString > > QgsVectorTileBasicLabelProvider::usedAttributes	(	const QgsRenderContext &	context,
		int	tileZoom
	)		const

overridevirtual

Returns field names for each sub-layer that are required for labeling.

Implements QgsVectorTileLabelProvider.

Definition at line 126 of file qgsvectortilebasiclabeling.cpp.

Member Data Documentation

◆ mPerLayerFields

QMap<QString, QgsFields> QgsVectorTileBasicLabelProvider::mPerLayerFields

Names of required fields for each sub-layer (only valid between startRender/stopRender calls)

Definition at line 207 of file qgsvectortilebasiclabeling.h.

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

/build/qgis-3.34.0+99sid/src/core/vectortile/qgsvectortilebasiclabeling.h
/build/qgis-3.34.0+99sid/src/core/vectortile/qgsvectortilebasiclabeling.cpp

Public Member Functions

Public Attributes

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QgsVectorTileBasicLabelProvider()

Member Function Documentation

◆ prepare()

◆ registerTileFeatures()

◆ requiredLayers()

◆ setFields()

◆ subProviders()

◆ usedAttributes()

Member Data Documentation

◆ mPerLayerFields