| QGIS API Documentation
    3.20.0-Odense (decaadbb31)
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Implements a derived label provider for use with QgsLabelSink. More...
#include <qgslabelsink.h>

| Public Member Functions | |
| QgsLabelSinkProvider (QgsVectorLayer *layer, const QString &providerId, QgsLabelSink *sink, const QgsPalLayerSettings *settings) | |
| Creates a rule based label sink provider which will draw/register labels in sink.  More... | |
| void | drawLabel (QgsRenderContext &context, pal::LabelPosition *label) const override | 
| Draw this label at the position determined by the labeling engine.  More... | |
|  Public Member Functions inherited from QgsVectorLayerLabelProvider | |
| 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.  More... | |
| QgsVectorLayerLabelProvider (QgsWkbTypes::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)  More... | |
| ~QgsVectorLayerLabelProvider () override | |
| void | drawLabel (QgsRenderContext &context, pal::LabelPosition *label) const override | 
| Draw this label at the position determined by the labeling engine.  More... | |
| void | drawLabelBackground (QgsRenderContext &context, pal::LabelPosition *label) const override | 
| Draw the background for the specified label.  More... | |
| void | drawUnplacedLabel (QgsRenderContext &context, pal::LabelPosition *label) const override | 
| Draw an unplaced label.  More... | |
| QList< QgsLabelFeature * > | labelFeatures (QgsRenderContext &context) override | 
| Returns list of label features (they are owned by the provider and thus deleted on its destruction)  More... | |
| virtual bool | prepare (QgsRenderContext &context, QSet< QString > &attributeNames) | 
| Prepare for registration of features.  More... | |
| virtual void | 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.  More... | |
| void | setFields (const QgsFields &fields) | 
| Sets fields of this label provider.  More... | |
| const QgsPalLayerSettings & | settings () const | 
| Returns the layer's settings.  More... | |
| void | startRender (QgsRenderContext &context) override | 
| To be called before rendering of labels begins.  More... | |
| void | stopRender (QgsRenderContext &context) override | 
| To be called after rendering is complete.  More... | |
|  Public Member Functions inherited from QgsAbstractLabelProvider | |
| QgsAbstractLabelProvider (QgsMapLayer *layer, const QString &providerId=QString()) | |
| Construct the provider with default values.  More... | |
| virtual | ~QgsAbstractLabelProvider ()=default | 
| Flags | flags () const | 
| Flags associated with the provider.  More... | |
| QgsMapLayer * | layer () const | 
| Returns the associated layer, or nullptrif no layer is associated with the provider.  More... | |
| QString | layerId () const | 
| Returns ID of associated layer, or empty string if no layer is associated with the provider.  More... | |
| QString | name () const | 
| Name of the layer (for statistics, debugging etc.) - does not need to be unique.  More... | |
| QgsLabelObstacleSettings::ObstacleType | obstacleType () const | 
| How the feature geometries will work as obstacles.  More... | |
| QgsPalLayerSettings::Placement | placement () const | 
| What placement strategy to use for the labels.  More... | |
| double | priority () const | 
| Default priority of labels (may be overridden by individual labels)  More... | |
| QString | providerId () const | 
| Returns provider ID - useful in case there is more than one label provider within a layer (e.g.  More... | |
| void | setEngine (const QgsLabelingEngine *engine) | 
| Associate provider with a labeling engine (should be only called internally from QgsLabelingEngine)  More... | |
| virtual QList< QgsAbstractLabelProvider * > | subProviders () | 
| Returns list of child providers - useful if the provider needs to put labels into more layers with different configuration.  More... | |
| QgsPalLayerSettings::UpsideDownLabels | upsidedownLabels () const | 
| How to handle labels that would be upside down.  More... | |
| Additional Inherited Members | |
|  Public Types inherited from QgsAbstractLabelProvider | |
| enum | Flag { DrawLabels = 1 << 1 , DrawAllLabels = 1 << 2 , 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.  More... | |
|  Protected Member Functions inherited from QgsVectorLayerLabelProvider | |
| void | drawLabelPrivate (pal::LabelPosition *label, QgsRenderContext &context, QgsPalLayerSettings &tmpLyr, QgsTextRenderer::TextPart drawType, double dpiRatio=1.0) const | 
| Internal label drawing method.  More... | |
| void | init () | 
| initialization method - called from constructors  More... | |
|  Protected Attributes inherited from QgsVectorLayerLabelProvider | |
| QgsCoordinateReferenceSystem | mCrs | 
| Layer's CRS.  More... | |
| QgsFields | mFields | 
| Layer's fields.  More... | |
| QList< QgsLabelFeature * > | mLabels | 
| List of generated.  More... | |
| QgsWkbTypes::GeometryType | mLayerGeometryType | 
| Geometry type of layer.  More... | |
| QgsFeatureRenderer * | mRenderer = nullptr | 
| QgsPalLayerSettings | mSettings | 
| Layer's labeling configuration.  More... | |
| std::unique_ptr< QgsAbstractFeatureSource > | mSource | 
| Layer's feature source.  More... | |
|  Protected Attributes inherited from QgsAbstractLabelProvider | |
| const QgsLabelingEngine * | mEngine = nullptr | 
| Associated labeling engine.  More... | |
| Flags | mFlags | 
| Flags altering drawing and registration of features.  More... | |
| QgsWeakMapLayerPointer | mLayer | 
| Weak pointer to source layer.  More... | |
| QString | mLayerId | 
| Associated layer's ID, if applicable.  More... | |
| QString | mName | 
| Name of the layer.  More... | |
| QgsLabelObstacleSettings::ObstacleType | mObstacleType = QgsLabelObstacleSettings::PolygonBoundary | 
| Type of the obstacle of feature geometries.  More... | |
| QgsPalLayerSettings::Placement | mPlacement | 
| Placement strategy.  More... | |
| double | mPriority | 
| Default priority of labels.  More... | |
| QString | mProviderId | 
| Associated provider ID (one layer may have multiple providers, e.g. in rule-based labeling)  More... | |
| QgsPalLayerSettings::UpsideDownLabels | mUpsidedownLabels | 
| How to handle labels that would be upside down.  More... | |
Implements a derived label provider for use with QgsLabelSink.
Definition at line 57 of file qgslabelsink.h.
| 
 | explicit | 
Creates a rule based label sink provider which will draw/register labels in sink.
Definition at line 23 of file qgslabelsink.cpp.
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 | overridevirtual | 
Draw this label at the position determined by the labeling engine.
Before any calls to drawLabel(), a provider should be prepared for rendering by a call to startRender() and a corresponding call to stopRender().
Implements QgsAbstractLabelProvider.
Definition at line 29 of file qgslabelsink.cpp.