QGIS API Documentation 3.41.0-Master (d5b93354e9c)
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#include <qgsrulebasedrenderer.h>
Classes | |
struct | FeatureToRender |
Feature for rendering by a QgsRuleBasedRenderer. More... | |
struct | RenderJob |
A QgsRuleBasedRenderer rendering job, consisting of a feature to be rendered with a particular symbol. More... | |
struct | RenderLevel |
Render level: a list of jobs to be drawn at particular level for a QgsRuleBasedRenderer. More... | |
class | Rule |
This class keeps data about a rules for rule-based renderer. More... | |
Public Types | |
enum | FeatureFlags { FeatIsSelected = 1 , FeatDrawMarkers = 2 } |
typedef QList< QgsRuleBasedRenderer::RenderLevel > | RenderQueue |
Rendering queue: a list of rendering levels. | |
typedef QList< QgsRuleBasedRenderer::Rule * > | RuleList |
Public Types inherited from QgsFeatureRenderer | |
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 | |
QgsRuleBasedRenderer (QgsRuleBasedRenderer::Rule *root) | |
Constructs the renderer from given tree of rules (takes ownership) | |
QgsRuleBasedRenderer (QgsSymbol *defaultSymbol) | |
Constructor for convenience. Creates a root rule and adds a default rule with symbol (takes ownership) | |
~QgsRuleBasedRenderer () override | |
bool | accept (QgsStyleEntityVisitorInterface *visitor) const override |
Accepts the specified symbology visitor, causing it to visit all symbols associated with the renderer. | |
bool | canSkipRender () override |
Returns true if the renderer can be entirely skipped, i.e. | |
QgsFeatureRenderer::Capabilities | capabilities () override |
Returns details about internals of this renderer. | |
void | checkLegendSymbolItem (const QString &key, bool state=true) override |
Sets whether the legend symbology item with the specified ley should be checked. | |
QgsRuleBasedRenderer * | clone () const override |
Create a deep copy of this renderer. | |
QString | dump () const override |
Returns debug information about this renderer. | |
QString | filter (const QgsFields &fields=QgsFields()) override |
If a renderer does not require all the features this method may be overridden and return an expression used as where clause. | |
bool | filterNeedsGeometry () const override |
Returns true if this renderer requires the geometry to apply the filter. | |
Qgis::FeatureRendererFlags | flags () const override |
Returns flags associated with the renderer. | |
QSet< QString > | legendKeysForFeature (const QgsFeature &feature, QgsRenderContext &context) const override |
Returns legend keys matching a specified feature. | |
QString | legendKeyToExpression (const QString &key, QgsVectorLayer *layer, bool &ok) const override |
Attempts to convert the specified legend rule key to a QGIS expression matching the features displayed using that key. | |
bool | legendSymbolItemChecked (const QString &key) override |
Returns true if the legend symbology item with the specified key is checked. | |
QgsLegendSymbolList | legendSymbolItems () const override |
Returns a list of symbology items for the legend. | |
bool | legendSymbolItemsCheckable () const override |
Returns true if symbology items in legend are checkable. | |
QgsSymbolList | originalSymbolsForFeature (const QgsFeature &feature, QgsRenderContext &context) const override |
Equivalent of originalSymbolsForFeature() call extended to support renderers that may use more symbols per feature - similar to symbolsForFeature() | |
bool | renderFeature (const QgsFeature &feature, QgsRenderContext &context, int layer=-1, bool selected=false, bool drawVertexMarker=false) override |
Render a feature using this renderer in the given context. | |
QgsRuleBasedRenderer::Rule * | rootRule () |
QDomElement | save (QDomDocument &doc, const QgsReadWriteContext &context) override |
Stores renderer properties to an XML element. | |
void | setLegendSymbolItem (const QString &key, QgsSymbol *symbol) override |
Sets the symbol to be used for a legend symbol item. | |
void | startRender (QgsRenderContext &context, const QgsFields &fields) override |
Must be called when a new render cycle is started. | |
void | stopRender (QgsRenderContext &context) override |
Must be called when a render cycle has finished, to allow the renderer to clean up. | |
QgsSymbol * | symbolForFeature (const QgsFeature &feature, QgsRenderContext &context) const override |
Returns symbol for current feature. Should not be used individually: there could be more symbols for a feature. | |
QgsSymbolList | symbols (QgsRenderContext &context) const override |
Returns list of symbols used by the renderer. | |
QgsSymbolList | symbolsForFeature (const QgsFeature &feature, QgsRenderContext &context) const override |
Returns list of symbols used for rendering the feature. | |
void | toSld (QDomDocument &doc, QDomElement &element, const QVariantMap &props=QVariantMap()) const override |
used from subclasses to create SLD Rule elements following SLD v1.1 specs | |
QSet< QString > | usedAttributes (const QgsRenderContext &context) const override |
Returns a list of attributes required by this renderer. | |
bool | willRenderFeature (const QgsFeature &feature, QgsRenderContext &context) const override |
Returns whether the renderer will render a feature or not. | |
Public Member Functions inherited from QgsFeatureRenderer | |
virtual | ~QgsFeatureRenderer () |
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 const QgsFeatureRenderer * | embeddedRenderer () const |
Returns the current embedded renderer (subrenderer) for this feature 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 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. | |
QgsPaintEffect * | paintEffect () const |
Returns the current paint effect for the renderer. | |
double | referenceScale () const |
Returns the symbology reference scale. | |
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. | |
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. | |
QString | type () const |
virtual bool | usesEmbeddedSymbols () const |
Returns true if the renderer uses embedded symbols for features. | |
bool | usingSymbolLevels () const |
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 QgsRuleBasedRenderer * | convertFromRenderer (const QgsFeatureRenderer *renderer, QgsVectorLayer *layer=nullptr) |
Creates a new QgsRuleBasedRenderer from an existing renderer. | |
static void | convertToDataDefinedSymbology (QgsSymbol *symbol, const QString &sizeScaleField, const QString &rotationField=QString()) |
helper function to convert the size scale and rotation fields present in some other renderers to data defined symbology | |
static QgsFeatureRenderer * | create (QDomElement &element, const QgsReadWriteContext &context) |
Creates a new rule-based renderer instance from XML. | |
static QgsFeatureRenderer * | createFromSld (QDomElement &element, Qgis::GeometryType geomType) |
Creates a new rule based renderer from an SLD XML element. | |
static void | refineRuleCategories (QgsRuleBasedRenderer::Rule *initialRule, QgsCategorizedSymbolRenderer *r) |
take a rule and create a list of new rules based on the categories from categorized symbol renderer | |
static void | refineRuleRanges (QgsRuleBasedRenderer::Rule *initialRule, QgsGraduatedSymbolRenderer *r) |
take a rule and create a list of new rules based on the ranges from graduated symbol renderer | |
static void | refineRuleScales (QgsRuleBasedRenderer::Rule *initialRule, QList< int > scales) |
take a rule and create a list of new rules with intervals of scales given by the passed scale denominators | |
Static Public Member Functions inherited from QgsFeatureRenderer | |
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 Attributes | |
QList< FeatureToRender > | mCurrentFeatures |
QString | mFilter |
RenderQueue | mRenderQueue |
Rule * | mRootRule = nullptr |
the root node with hierarchical list of rules | |
Protected Attributes inherited from QgsFeatureRenderer | |
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 |
Additional Inherited Members | |
Protected Member Functions inherited from QgsFeatureRenderer | |
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 inherited from QgsFeatureRenderer | |
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) |
Rule based renderer.
When drawing a vector layer with rule-based renderer, it goes through the rules and draws features with symbols from rules that match.
Definition at line 40 of file qgsrulebasedrenderer.h.
Rendering queue: a list of rendering levels.
Definition at line 134 of file qgsrulebasedrenderer.h.
typedef QList<QgsRuleBasedRenderer::Rule *> QgsRuleBasedRenderer::RuleList |
Definition at line 137 of file qgsrulebasedrenderer.h.
Enumerator | |
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FeatIsSelected | |
FeatDrawMarkers |
Definition at line 45 of file qgsrulebasedrenderer.h.
QgsRuleBasedRenderer::QgsRuleBasedRenderer | ( | QgsRuleBasedRenderer::Rule * | root | ) |
Constructs the renderer from given tree of rules (takes ownership)
Definition at line 961 of file qgsrulebasedrenderer.cpp.
QgsRuleBasedRenderer::QgsRuleBasedRenderer | ( | QgsSymbol * | defaultSymbol | ) |
Constructor for convenience. Creates a root rule and adds a default rule with symbol (takes ownership)
Definition at line 967 of file qgsrulebasedrenderer.cpp.
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Definition at line 974 of file qgsrulebasedrenderer.cpp.
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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.
Reimplemented from QgsFeatureRenderer.
Definition at line 1455 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
Returns true
if the renderer can be entirely skipped, i.e.
if it is known in advance that no features will be rendered.
Reimplemented from QgsFeatureRenderer.
Definition at line 1054 of file qgsrulebasedrenderer.cpp.
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inlineoverridevirtual |
Returns details about internals of this renderer.
E.g. if you only want to deal with visible features:
Reimplemented from QgsFeatureRenderer.
Definition at line 547 of file qgsrulebasedrenderer.h.
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overridevirtual |
Sets whether the legend symbology item with the specified ley should be checked.
Reimplemented from QgsFeatureRenderer.
Definition at line 1182 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
Create a deep copy of this renderer.
Should be implemented by all subclasses and generate a proper subclass.
Implements QgsFeatureRenderer.
Definition at line 1122 of file qgsrulebasedrenderer.cpp.
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Creates a new QgsRuleBasedRenderer from an existing renderer.
Since QGIS 3.20, the optional layer parameter is required for conversions of some renderer types.
nullptr
. Definition at line 1460 of file qgsrulebasedrenderer.cpp.
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helper function to convert the size scale and rotation fields present in some other renderers to data defined symbology
Definition at line 1692 of file qgsrulebasedrenderer.cpp.
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Creates a new rule-based renderer instance from XML.
Definition at line 1285 of file qgsrulebasedrenderer.cpp.
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Creates a new rule based renderer from an SLD XML element.
Definition at line 1308 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
Returns debug information about this renderer.
Reimplemented from QgsFeatureRenderer.
Definition at line 1428 of file qgsrulebasedrenderer.cpp.
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.
Reimplemented from QgsFeatureRenderer.
Definition at line 1107 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
Returns true
if this renderer requires the geometry to apply the filter.
Reimplemented from QgsFeatureRenderer.
Definition at line 1117 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
Returns flags associated with the renderer.
Reimplemented from QgsFeatureRenderer.
Definition at line 986 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
Returns legend keys matching a specified feature.
Reimplemented from QgsFeatureRenderer.
Definition at line 1450 of file qgsrulebasedrenderer.cpp.
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Attempts to convert the specified legend rule key to a QGIS expression matching the features displayed using that key.
key | legend key |
layer | associated vector layer |
ok | will be set to true if legend key was successfully converted to a filter expression |
Reimplemented from QgsFeatureRenderer.
Definition at line 1189 of file qgsrulebasedrenderer.cpp.
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Returns true
if the legend symbology item with the specified key is checked.
Reimplemented from QgsFeatureRenderer.
Definition at line 1176 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
Returns a list of symbology items for the legend.
Reimplemented from QgsFeatureRenderer.
Definition at line 1279 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
Returns true
if symbology items in legend are checkable.
Reimplemented from QgsFeatureRenderer.
Definition at line 1171 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
Equivalent of originalSymbolsForFeature() call extended to support renderers that may use more symbols per feature - similar to symbolsForFeature()
Reimplemented from QgsFeatureRenderer.
Definition at line 1445 of file qgsrulebasedrenderer.cpp.
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take a rule and create a list of new rules based on the categories from categorized symbol renderer
Definition at line 1342 of file qgsrulebasedrenderer.cpp.
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take a rule and create a list of new rules based on the ranges from graduated symbol renderer
Definition at line 1376 of file qgsrulebasedrenderer.cpp.
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take a rule and create a list of new rules with intervals of scales given by the passed scale denominators
Definition at line 1408 of file qgsrulebasedrenderer.cpp.
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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).
Reimplemented from QgsFeatureRenderer.
Definition at line 1012 of file qgsrulebasedrenderer.cpp.
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Definition at line 552 of file qgsrulebasedrenderer.h.
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overridevirtual |
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 from QgsFeatureRenderer.
Definition at line 1152 of file qgsrulebasedrenderer.cpp.
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Sets the symbol to be used for a legend symbol item.
key | rule key for legend symbol |
symbol | new symbol for legend item. Ownership is transferred to renderer. |
Reimplemented from QgsFeatureRenderer.
Definition at line 1270 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
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.
context | Additional information passed to the renderer about the job which will be rendered |
fields | The fields available for rendering |
Reimplemented from QgsFeatureRenderer.
Definition at line 1028 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
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().
Reimplemented from QgsFeatureRenderer.
Definition at line 1059 of file qgsrulebasedrenderer.cpp.
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Returns symbol for current feature. Should not be used individually: there could be more symbols for a feature.
Implements QgsFeatureRenderer.
Definition at line 980 of file qgsrulebasedrenderer.cpp.
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Returns list of symbols used by the renderer.
context | render context |
Reimplemented from QgsFeatureRenderer.
Definition at line 1147 of file qgsrulebasedrenderer.cpp.
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Returns list of symbols used for rendering the feature.
For renderers that do not support MoreSymbolsPerFeature it is more efficient to use symbolForFeature()
Reimplemented from QgsFeatureRenderer.
Definition at line 1440 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
used from subclasses to create SLD Rule elements following SLD v1.1 specs
Reimplemented from QgsFeatureRenderer.
Definition at line 1141 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
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.
Implements QgsFeatureRenderer.
Definition at line 1112 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
Returns whether the renderer will render a feature or not.
Must be called between startRender() and stopRender() calls. Default implementation uses symbolForFeature().
Reimplemented from QgsFeatureRenderer.
Definition at line 1435 of file qgsrulebasedrenderer.cpp.
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Definition at line 581 of file qgsrulebasedrenderer.h.
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Definition at line 583 of file qgsrulebasedrenderer.h.
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Definition at line 580 of file qgsrulebasedrenderer.h.
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the root node with hierarchical list of rules
Definition at line 577 of file qgsrulebasedrenderer.h.