QGIS API Documentation
3.6.0-Noosa (5873452)
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When drawing a vector layer with rule-based renderer, it goes through the rules and draws features with symbols from rules that match. More...
#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. More... | |
typedef QList< QgsRuleBasedRenderer::Rule * > | RuleList |
Public Types inherited from QgsFeatureRenderer | |
enum | Capability { SymbolLevels = 1, MoreSymbolsPerFeature = 1 << 2, Filter = 1 << 3, ScaleDependent = 1 << 4 } |
Used to specify details about a renderer. More... | |
Public Member Functions | |
QgsRuleBasedRenderer (QgsRuleBasedRenderer::Rule *root) | |
Constructs the renderer from given tree of rules (takes ownership) More... | |
QgsRuleBasedRenderer (QgsSymbol *defaultSymbol) | |
Constructor for convenience. Creates a root rule and adds a default rule with symbol (takes ownership) More... | |
~QgsRuleBasedRenderer () override | |
QgsFeatureRenderer::Capabilities | capabilities () override |
Returns details about internals of this renderer. More... | |
void | checkLegendSymbolItem (const QString &key, bool state=true) override |
item in symbology was checked More... | |
QgsRuleBasedRenderer * | clone () const override |
Create a deep copy of this renderer. More... | |
QString | dump () const override |
Returns debug information about this renderer. More... | |
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. More... | |
bool | filterNeedsGeometry () const override |
Returns true if this renderer requires the geometry to apply the filter. More... | |
QSet< QString > | legendKeysForFeature (const QgsFeature &feature, QgsRenderContext &context) const override |
Returns legend keys matching a specified feature. More... | |
bool | legendSymbolItemChecked (const QString &key) override |
items of symbology items in legend is checked More... | |
QgsLegendSymbolList | legendSymbolItems () const override |
Returns a list of symbology items for the legend. More... | |
bool | legendSymbolItemsCheckable () const override |
items of symbology items in legend should be checkable More... | |
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() More... | |
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. More... | |
QgsRuleBasedRenderer::Rule * | rootRule () |
QDomElement | save (QDomDocument &doc, const QgsReadWriteContext &context) override |
store renderer info to XML element More... | |
void | setLegendSymbolItem (const QString &key, QgsSymbol *symbol) override |
Sets the symbol to be used for a legend symbol item. More... | |
void | startRender (QgsRenderContext &context, const QgsFields &fields) override |
Must be called when a new render cycle is started. More... | |
void | stopRender (QgsRenderContext &context) override |
Must be called when a render cycle has finished, to allow the renderer to clean up. More... | |
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. More... | |
QgsSymbolList | symbols (QgsRenderContext &context) const override |
Returns list of symbols used by the renderer. More... | |
QgsSymbolList | symbolsForFeature (const QgsFeature &feature, QgsRenderContext &context) const override |
Returns list of symbols used for rendering the feature. More... | |
void | toSld (QDomDocument &doc, QDomElement &element, const QgsStringMap &props=QgsStringMap()) const override |
used from subclasses to create SLD Rule elements following SLD v1.1 specs More... | |
QSet< QString > | usedAttributes (const QgsRenderContext &context) const override |
Returns a list of attributes required by this renderer. More... | |
bool | willRenderFeature (const QgsFeature &feature, QgsRenderContext &context) const override |
Returns whether the renderer will render a feature or not. More... | |
Public Member Functions inherited from QgsFeatureRenderer | |
virtual | ~QgsFeatureRenderer () |
virtual const QgsFeatureRenderer * | embeddedRenderer () const |
Returns the current embedded renderer (subrenderer) for this feature renderer. More... | |
bool | forceRasterRender () const |
Returns whether the renderer must render as a raster. More... | |
virtual QString | legendClassificationAttribute () const |
If supported by the renderer, return classification attribute for the use in legend. More... | |
virtual void | modifyRequestExtent (QgsRectangle &extent, QgsRenderContext &context) |
Allows for a renderer to modify the extent of a feature request prior to rendering. More... | |
QgsFeatureRequest::OrderBy | orderBy () const |
Gets the order in which features shall be processed by this renderer. More... | |
bool | orderByEnabled () const |
Returns whether custom ordering will be applied before features are processed by this renderer. More... | |
virtual QgsSymbol * | originalSymbolForFeature (const QgsFeature &feature, QgsRenderContext &context) const |
Returns symbol for feature. More... | |
QgsPaintEffect * | paintEffect () const |
Returns the current paint effect for the renderer. More... | |
virtual void | setEmbeddedRenderer (QgsFeatureRenderer *subRenderer) |
Sets an embedded renderer (subrenderer) for this feature renderer. More... | |
void | setForceRasterRender (bool forceRaster) |
Sets whether the renderer should be rendered to a raster destination. More... | |
void | setOrderBy (const QgsFeatureRequest::OrderBy &orderBy) |
Define the order in which features shall be processed by this renderer. More... | |
void | setOrderByEnabled (bool enabled) |
Sets whether custom ordering should be applied before features are processed by this renderer. More... | |
void | setPaintEffect (QgsPaintEffect *effect) |
Sets the current paint effect for the renderer. More... | |
void | setUsingSymbolLevels (bool usingSymbolLevels) |
void | setVertexMarkerAppearance (int type, double size) |
Sets type and size of editing vertex markers for subsequent rendering. More... | |
QString | type () const |
bool | usingSymbolLevels () const |
virtual QDomElement | writeSld (QDomDocument &doc, const QString &styleName, const QgsStringMap &props=QgsStringMap()) const |
create the SLD UserStyle element following the SLD v1.1 specs with the given name More... | |
Static Public Member Functions | |
static QgsRuleBasedRenderer * | convertFromRenderer (const QgsFeatureRenderer *renderer) |
creates a QgsRuleBasedRenderer from an existing renderer. More... | |
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 More... | |
static QgsFeatureRenderer * | create (QDomElement &element, const QgsReadWriteContext &context) |
Creates a new rule-based renderer instance from XML. More... | |
static QgsFeatureRenderer * | createFromSld (QDomElement &element, QgsWkbTypes::GeometryType geomType) |
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 More... | |
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 More... | |
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 More... | |
Static Public Member Functions inherited from QgsFeatureRenderer | |
static QgsFeatureRenderer * | defaultRenderer (QgsWkbTypes::GeometryType geomType) |
Returns a new renderer - used by default in vector layers. More... | |
static QgsFeatureRenderer * | load (QDomElement &symbologyElem, const QgsReadWriteContext &context) |
create a renderer from XML element More... | |
static QgsFeatureRenderer * | loadSld (const QDomNode &node, QgsWkbTypes::GeometryType geomType, QString &errorMessage) |
Create a new renderer according to the information contained in the UserStyle element of a SLD style document. More... | |
Protected Attributes | |
QList< FeatureToRender > | mCurrentFeatures |
QString | mFilter |
RenderQueue | mRenderQueue |
Rule * | mRootRule = nullptr |
the root node with hierarchical list of rules More... | |
Protected Attributes inherited from QgsFeatureRenderer | |
double | mCurrentVertexMarkerSize |
The current size of editing marker. More... | |
int | mCurrentVertexMarkerType |
The current type of editing marker. More... | |
bool | mForceRaster |
QgsFeatureRequest::OrderBy | mOrderBy |
bool | mOrderByEnabled |
QgsPaintEffect * | mPaintEffect = nullptr |
QString | mType |
bool | mUsingSymbolLevels |
Additional Inherited Members | |
Protected Member Functions inherited from QgsFeatureRenderer | |
QgsFeatureRenderer (const QString &type) | |
void | copyRendererData (QgsFeatureRenderer *destRenderer) const |
Clones generic renderer data to another renderer. More... | |
void | renderFeatureWithSymbol (const QgsFeature &feature, QgsSymbol *symbol, QgsRenderContext &context, int layer, bool selected, bool drawVertexMarker) |
Render the feature with the symbol using context. More... | |
void | renderVertexMarker (QPointF pt, QgsRenderContext &context) |
render editing vertex marker at specified point More... | |
void | renderVertexMarkerPolygon (QPolygonF &pts, QList< QPolygonF > *rings, QgsRenderContext &context) |
render editing vertex marker for a polygon More... | |
void | renderVertexMarkerPolyline (QPolygonF &pts, QgsRenderContext &context) |
render editing vertex marker for a polyline More... | |
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. More... | |
static void | convertSymbolRotation (QgsSymbol *symbol, const QString &field) |
static void | convertSymbolSizeScale (QgsSymbol *symbol, QgsSymbol::ScaleMethod method, const QString &field) |
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 37 of file qgsrulebasedrenderer.h.
Rendering queue: a list of rendering levels.
Definition at line 117 of file qgsrulebasedrenderer.h.
typedef QList<QgsRuleBasedRenderer::Rule *> QgsRuleBasedRenderer::RuleList |
Definition at line 119 of file qgsrulebasedrenderer.h.
Enumerator | |
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FeatIsSelected | |
FeatDrawMarkers |
Definition at line 42 of file qgsrulebasedrenderer.h.
QgsRuleBasedRenderer::QgsRuleBasedRenderer | ( | QgsRuleBasedRenderer::Rule * | root | ) |
Constructs the renderer from given tree of rules (takes ownership)
Definition at line 857 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 863 of file qgsrulebasedrenderer.cpp.
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override |
Definition at line 870 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 511 of file qgsrulebasedrenderer.h.
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overridevirtual |
item in symbology was checked
Reimplemented from QgsFeatureRenderer.
Definition at line 1054 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 982 of file qgsrulebasedrenderer.cpp.
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creates a QgsRuleBasedRenderer from an existing renderer.
Definition at line 1240 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 1422 of file qgsrulebasedrenderer.cpp.
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Creates a new rule-based renderer instance from XML.
Definition at line 1076 of file qgsrulebasedrenderer.cpp.
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Definition at line 1099 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
Returns debug information about this renderer.
Reimplemented from QgsFeatureRenderer.
Definition at line 1213 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 967 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 977 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
Returns legend keys matching a specified feature.
Reimplemented from QgsFeatureRenderer.
Definition at line 1235 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
items of symbology items in legend is checked
Reimplemented from QgsFeatureRenderer.
Definition at line 1048 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
Returns a list of symbology items for the legend.
Reimplemented from QgsFeatureRenderer.
Definition at line 1070 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
items of symbology items in legend should be checkable
Reimplemented from QgsFeatureRenderer.
Definition at line 1043 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 1230 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 1133 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 1163 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 1194 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
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 particula layer from symbols (in order to support symbol level rendering).
Reimplemented from QgsFeatureRenderer.
Definition at line 882 of file qgsrulebasedrenderer.cpp.
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inline |
Definition at line 515 of file qgsrulebasedrenderer.h.
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overridevirtual |
store renderer info to XML element
Reimplemented from QgsFeatureRenderer.
Definition at line 1013 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 1061 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 898 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 923 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 876 of file qgsrulebasedrenderer.cpp.
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overridevirtual |
Returns list of symbols used by the renderer.
context | render context |
Reimplemented from QgsFeatureRenderer.
Definition at line 1008 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 1225 of file qgsrulebasedrenderer.cpp.
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used from subclasses to create SLD Rule elements following SLD v1.1 specs
Reimplemented from QgsFeatureRenderer.
Definition at line 1002 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 972 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 1220 of file qgsrulebasedrenderer.cpp.
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Definition at line 542 of file qgsrulebasedrenderer.h.
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Definition at line 544 of file qgsrulebasedrenderer.h.
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Definition at line 541 of file qgsrulebasedrenderer.h.
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the root node with hierarchical list of rules
Definition at line 538 of file qgsrulebasedrenderer.h.