Implements a derived label provider for use with QgsLabelSink. More...
#include <qgslabelsink.h>
Inheritance diagram for QgsLabelSinkProvider:
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... | |
| void | drawUnplacedLabel (QgsRenderContext &context, pal::LabelPosition *label) const override |
| Draw an unplaced label. More... | |
 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) More... | |
| 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 () 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 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. 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 |
| virtual void | drawLabel (QgsRenderContext &context, pal::LabelPosition *label) const =0 |
| Draw this label at the position determined by the labeling engine. More... | |
| virtual void | drawLabelBackground (QgsRenderContext &context, pal::LabelPosition *label) const |
| Draw the background for the specified label. More... | |
| virtual void | drawUnplacedLabel (QgsRenderContext &context, pal::LabelPosition *label) const |
| Draw an unplaced label. More... | |
| Flags | flags () const |
| Flags associated with the provider. More... | |
| virtual QList< QgsLabelFeature * > | labelFeatures (QgsRenderContext &context)=0 |
| Returns list of label features (they are owned by the provider and thus deleted on its destruction) More... | |
| QgsMapLayer * | layer () const |
Returns the associated layer, or nullptr if no layer is associated with the provider. More... | |
| QgsExpressionContextScope * | layerExpressionContextScope () const |
| Returns the expression context scope created from the layer associated with this provider. More... | |
| QString | layerId () const |
| Returns ID of associated layer, or empty string if no layer is associated with the provider. More... | |
| double | layerReferenceScale () const |
| Returns the symbology reference scale of the layer associated with this 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... | |
| Qgis::LabelPlacement | 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 void | startRender (QgsRenderContext &context) |
| To be called before rendering of labels begins. More... | |
| virtual void | stopRender (QgsRenderContext &context) |
| To be called after rendering is complete. 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... | |
| Qgis::UpsideDownLabelHandling | 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 , 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, Qgis::TextComponent 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... | |
| Qgis::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 = DrawLabels |
| 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... | |
| Qgis::LabelPlacement | mPlacement = Qgis::LabelPlacement::AroundPoint |
| Placement strategy. More... | |
| double | mPriority = 0.5 |
| Default priority of labels. More... | |
| QString | mProviderId |
| Associated provider ID (one layer may have multiple providers, e.g. in rule-based labeling) More... | |
| Qgis::UpsideDownLabelHandling | mUpsidedownLabels = Qgis::UpsideDownLabelHandling::FlipUpsideDownLabels |
| How to handle labels that would be upside down. More... | |
Detailed Description
Implements a derived label provider for use with QgsLabelSink.
- Note
- not available in Python bindings
- Since
- QGIS 3.14
Definition at line 74 of file qgslabelsink.h.
Constructor & Destructor Documentation
◆ QgsLabelSinkProvider()
|
explicit |
Creates a rule based label sink provider which will draw/register labels in sink.
Definition at line 23 of file qgslabelsink.cpp.
Member Function Documentation
◆ drawLabel()
|
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.
◆ drawUnplacedLabel()
|
overridevirtual |
Draw an unplaced label.
These correspond to features which were registered for labeling, but which could not be labeled (e.g. due to conflicting labels).
The default behavior is to draw nothing for these labels.
- Note
- This method is only used if the Qgis::Qgis::LabelingFlag::DrawUnplacedLabels flag is set on the labeling engine.
- Since
- QGIS 3.10
Reimplemented from QgsAbstractLabelProvider.
Definition at line 35 of file qgslabelsink.cpp.
The documentation for this class was generated from the following files:
- /build/qgis-3.30.0+99sid/src/core/labeling/qgslabelsink.h
- /build/qgis-3.30.0+99sid/src/core/labeling/qgslabelsink.cpp
