QGIS API Documentation 3.37.0-Master (fdefdf9c27f)
Public Member Functions | Static Public Member Functions | Protected Attributes | List of all members
QgsSingleSymbolRenderer Class Reference

#include <qgssinglesymbolrenderer.h>

Inheritance diagram for QgsSingleSymbolRenderer:
Inheritance graph
[legend]

Public Member Functions

 QgsSingleSymbolRenderer (QgsSymbol *symbol)
 Constructor for QgsSingleSymbolRenderer. More...
 
 ~QgsSingleSymbolRenderer () override
 
bool accept (QgsStyleEntityVisitorInterface *visitor) const override
 Accepts the specified symbology visitor, causing it to visit all symbols associated with the renderer. More...
 
QgsFeatureRenderer::Capabilities capabilities () override
 Returns details about internals of this renderer. More...
 
QgsSingleSymbolRendererclone () const override
 Create a deep copy of this renderer. More...
 
QgsDataDefinedSizeLegenddataDefinedSizeLegend () const
 Returns configuration of appearance of legend when using data-defined size for marker symbols. More...
 
QString dump () const override
 Returns debug information about this renderer. More...
 
QSet< QString > legendKeysForFeature (const QgsFeature &feature, QgsRenderContext &context) const override
 Returns legend keys matching a specified feature. More...
 
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. More...
 
QgsLegendSymbolList legendSymbolItems () const override
 Returns a list of symbology items for the legend. More...
 
QgsSymboloriginalSymbolForFeature (const QgsFeature &feature, QgsRenderContext &context) const override
 Returns symbol for feature. More...
 
QDomElement save (QDomDocument &doc, const QgsReadWriteContext &context) override
 Stores renderer properties to an XML element. More...
 
void setDataDefinedSizeLegend (QgsDataDefinedSizeLegend *settings)
 Configures appearance of legend when renderer is configured to use data-defined size for marker symbols. More...
 
void setLegendSymbolItem (const QString &key, QgsSymbol *symbol) override
 Sets the symbol to be used for a legend symbol item. More...
 
void setSymbol (QgsSymbol *s)
 Sets the symbol which will be rendered for every feature. 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...
 
QgsSymbolsymbol () const
 Returns the symbol which will be rendered for every feature. More...
 
QgsSymbolsymbolForFeature (const QgsFeature &feature, QgsRenderContext &context) const override
 To be overridden. More...
 
QgsSymbolList symbols (QgsRenderContext &context) const override
 Returns list of symbols used by the renderer. More...
 
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 More...
 
QSet< QString > usedAttributes (const QgsRenderContext &context) const override
 Returns a list of attributes required by this renderer. More...
 
- Public Member Functions inherited from QgsFeatureRenderer
virtual ~QgsFeatureRenderer ()
 
virtual bool accept (QgsStyleEntityVisitorInterface *visitor) const
 Accepts the specified symbology visitor, causing it to visit all symbols associated with the renderer. More...
 
virtual bool canSkipRender ()
 Returns true if the renderer can be entirely skipped, i.e. More...
 
virtual QgsFeatureRenderer::Capabilities capabilities ()
 Returns details about internals of this renderer. More...
 
virtual void checkLegendSymbolItem (const QString &key, bool state=true)
 Sets whether the legend symbology item with the specified ley should be checked. More...
 
virtual QgsFeatureRendererclone () const =0
 Create a deep copy of this renderer. More...
 
void copyRendererData (QgsFeatureRenderer *destRenderer) const
 Clones generic renderer data to another renderer. More...
 
virtual QString dump () const
 Returns debug information about this renderer. More...
 
virtual const QgsFeatureRendererembeddedRenderer () const
 Returns the current embedded renderer (subrenderer) for this feature renderer. More...
 
virtual QString filter (const QgsFields &fields=QgsFields())
 If a renderer does not require all the features this method may be overridden and return an expression used as where clause. More...
 
virtual bool filterNeedsGeometry () const
 Returns true if this renderer requires the geometry to apply the filter. 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...
 
QSet< QString > legendKeys () const
 Returns the set of all legend keys used by the renderer. More...
 
virtual QSet< QString > legendKeysForFeature (const QgsFeature &feature, QgsRenderContext &context) const
 Returns legend keys matching a specified feature. More...
 
virtual QString legendKeyToExpression (const QString &key, QgsVectorLayer *layer, bool &ok) const
 Attempts to convert the specified legend rule key to a QGIS expression matching the features displayed using that key. More...
 
virtual bool legendSymbolItemChecked (const QString &key)
 Returns true if the legend symbology item with the specified key is checked. More...
 
virtual QgsLegendSymbolList legendSymbolItems () const
 Returns a list of symbology items for the legend. More...
 
virtual bool legendSymbolItemsCheckable () const
 Returns true if symbology items in legend are checkable. 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 QgsSymboloriginalSymbolForFeature (const QgsFeature &feature, QgsRenderContext &context) const
 Returns symbol for feature. More...
 
virtual QgsSymbolList originalSymbolsForFeature (const QgsFeature &feature, QgsRenderContext &context) const
 Equivalent of originalSymbolsForFeature() call extended to support renderers that may use more symbols per feature - similar to symbolsForFeature() More...
 
QgsPaintEffectpaintEffect () const
 Returns the current paint effect for the renderer. More...
 
double referenceScale () const
 Returns the symbology reference scale. More...
 
virtual bool renderFeature (const QgsFeature &feature, QgsRenderContext &context, int layer=-1, bool selected=false, bool drawVertexMarker=false)
 Render a feature using this renderer in the given context. More...
 
virtual QDomElement save (QDomDocument &doc, const QgsReadWriteContext &context)
 Stores renderer properties to an XML element. 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...
 
virtual void setLegendSymbolItem (const QString &key, QgsSymbol *symbol)
 Sets the symbol to be used for a legend symbol item. 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 setReferenceScale (double scale)
 Sets the symbology reference scale. More...
 
void setUsingSymbolLevels (bool usingSymbolLevels)
 
void setVertexMarkerAppearance (Qgis::VertexMarkerType type, double size)
 Sets type and size of editing vertex markers for subsequent rendering. More...
 
virtual void startRender (QgsRenderContext &context, const QgsFields &fields)
 Must be called when a new render cycle is started. More...
 
virtual void stopRender (QgsRenderContext &context)
 Must be called when a render cycle has finished, to allow the renderer to clean up. More...
 
virtual QgsSymbolsymbolForFeature (const QgsFeature &feature, QgsRenderContext &context) const =0
 To be overridden. More...
 
virtual QgsSymbolList symbols (QgsRenderContext &context) const
 Returns list of symbols used by the renderer. More...
 
virtual QgsSymbolList symbolsForFeature (const QgsFeature &feature, QgsRenderContext &context) const
 Returns list of symbols used for rendering the feature. More...
 
virtual void toSld (QDomDocument &doc, QDomElement &element, const QVariantMap &props=QVariantMap()) const
 used from subclasses to create SLD Rule elements following SLD v1.1 specs More...
 
QString type () const
 
virtual QSet< QString > usedAttributes (const QgsRenderContext &context) const =0
 Returns a list of attributes required by this renderer. More...
 
virtual bool usesEmbeddedSymbols () const
 Returns true if the renderer uses embedded symbols for features. More...
 
bool usingSymbolLevels () const
 
virtual bool willRenderFeature (const QgsFeature &feature, QgsRenderContext &context) const
 Returns whether the renderer will render a feature or not. More...
 
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 More...
 

Static Public Member Functions

static QgsSingleSymbolRendererconvertFromRenderer (const QgsFeatureRenderer *renderer)
 Creates a new single symbol renderer from an existing renderer. More...
 
static QgsFeatureRenderercreate (QDomElement &element, const QgsReadWriteContext &context)
 Creates a new single symbol renderer from an XML element, using the supplied read/write context. More...
 
static QgsFeatureRenderercreateFromSld (QDomElement &element, Qgis::GeometryType geomType)
 Creates a new single symbol renderer from an SLD element. More...
 
- Static Public Member Functions inherited from QgsFeatureRenderer
static QgsFeatureRendererdefaultRenderer (Qgis::GeometryType geomType)
 Returns a new renderer - used by default in vector layers. More...
 
static QgsFeatureRendererload (QDomElement &symbologyElem, const QgsReadWriteContext &context)
 create a renderer from XML element More...
 
static QgsFeatureRendererloadSld (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. More...
 

Protected Attributes

std::unique_ptr< QgsDataDefinedSizeLegendmDataDefinedSizeLegend
 
std::unique_ptr< QgsSymbolmSymbol
 
- Protected Attributes inherited from QgsFeatureRenderer
double mCurrentVertexMarkerSize = 2
 The current size of editing marker. More...
 
Qgis::VertexMarkerType mCurrentVertexMarkerType = Qgis::VertexMarkerType::Cross
 The current type of editing marker. More...
 
bool mForceRaster = false
 
QgsFeatureRequest::OrderBy mOrderBy
 
bool mOrderByEnabled = false
 
QgsPaintEffectmPaintEffect = nullptr
 
double mReferenceScale = -1.0
 
QString mType
 
bool mUsingSymbolLevels = false
 

Additional Inherited Members

- Public Types inherited from QgsFeatureRenderer
typedef QFlags< CapabilityCapabilities
 
enum  Capability { SymbolLevels = 1 , MoreSymbolsPerFeature = 1 << 2 , Filter = 1 << 3 , ScaleDependent = 1 << 4 }
 Used to specify details about a renderer. More...
 
- 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. 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...
 
void saveRendererData (QDomDocument &doc, QDomElement &element, const QgsReadWriteContext &context)
 Saves generic renderer data into the specified element. 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, Qgis::ScaleMethod method, const QString &field)
 

Detailed Description

Definition at line 29 of file qgssinglesymbolrenderer.h.

Constructor & Destructor Documentation

◆ QgsSingleSymbolRenderer()

QgsSingleSymbolRenderer::QgsSingleSymbolRenderer ( QgsSymbol symbol)

Constructor for QgsSingleSymbolRenderer.

The same symbol will be used to render every feature. Ownership of symbol is transferred to the renderer.

Definition at line 40 of file qgssinglesymbolrenderer.cpp.

◆ ~QgsSingleSymbolRenderer()

QgsSingleSymbolRenderer::~QgsSingleSymbolRenderer ( )
overridedefault

Member Function Documentation

◆ accept()

bool QgsSingleSymbolRenderer::accept ( QgsStyleEntityVisitorInterface visitor) const
overridevirtual

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.

Since
QGIS 3.10

Reimplemented from QgsFeatureRenderer.

Definition at line 89 of file qgssinglesymbolrenderer.cpp.

◆ capabilities()

QgsFeatureRenderer::Capabilities QgsSingleSymbolRenderer::capabilities ( )
inlineoverridevirtual

Returns details about internals of this renderer.

E.g. if you only want to deal with visible features:

if not renderer.capabilities().testFlag(QgsFeatureRenderer.Filter) or renderer.willRenderFeature(feature, context):
deal_with_my_feature()
else:
skip_the_curren_feature()

Reimplemented from QgsFeatureRenderer.

Definition at line 77 of file qgssinglesymbolrenderer.h.

◆ clone()

QgsSingleSymbolRenderer * QgsSingleSymbolRenderer::clone ( ) const
overridevirtual

Create a deep copy of this renderer.

Should be implemented by all subclasses and generate a proper subclass.

Returns
A copy of this renderer

Implements QgsFeatureRenderer.

Definition at line 115 of file qgssinglesymbolrenderer.cpp.

◆ convertFromRenderer()

QgsSingleSymbolRenderer * QgsSingleSymbolRenderer::convertFromRenderer ( const QgsFeatureRenderer renderer)
static

Creates a new single symbol renderer from an existing renderer.

Returns
a new renderer if the conversion was possible, otherwise nullptr.

Definition at line 350 of file qgssinglesymbolrenderer.cpp.

◆ create()

QgsFeatureRenderer * QgsSingleSymbolRenderer::create ( QDomElement &  element,
const QgsReadWriteContext context 
)
static

Creates a new single symbol renderer from an XML element, using the supplied read/write context.

The caller takes ownership of the returned renderer.

Definition at line 148 of file qgssinglesymbolrenderer.cpp.

◆ createFromSld()

QgsFeatureRenderer * QgsSingleSymbolRenderer::createFromSld ( QDomElement &  element,
Qgis::GeometryType  geomType 
)
static

Creates a new single symbol renderer from an SLD element.

The geometry type for features to be rendered must be specified via the geomType argument.

The caller takes ownership of the returned renderer.

Definition at line 188 of file qgssinglesymbolrenderer.cpp.

◆ dataDefinedSizeLegend()

QgsDataDefinedSizeLegend * QgsSingleSymbolRenderer::dataDefinedSizeLegend ( ) const

Returns configuration of appearance of legend when using data-defined size for marker symbols.

Will return nullptr if the functionality is disabled.

Definition at line 393 of file qgssinglesymbolrenderer.cpp.

◆ dump()

QString QgsSingleSymbolRenderer::dump ( ) const
overridevirtual

Returns debug information about this renderer.

Reimplemented from QgsFeatureRenderer.

Definition at line 110 of file qgssinglesymbolrenderer.cpp.

◆ legendKeysForFeature()

QSet< QString > QgsSingleSymbolRenderer::legendKeysForFeature ( const QgsFeature feature,
QgsRenderContext context 
) const
overridevirtual

Returns legend keys matching a specified feature.

Reimplemented from QgsFeatureRenderer.

Definition at line 323 of file qgssinglesymbolrenderer.cpp.

◆ legendKeyToExpression()

QString QgsSingleSymbolRenderer::legendKeyToExpression ( const QString &  key,
QgsVectorLayer layer,
bool &  ok 
) const
overridevirtual

Attempts to convert the specified legend rule key to a QGIS expression matching the features displayed using that key.

Parameters
keylegend key
layerassociated vector layer
okwill be set to true if legend key was successfully converted to a filter expression
Returns
QGIS expression string for matching features with the specified key
See also
legendKeys()
Since
QGIS 3.26

Reimplemented from QgsFeatureRenderer.

Definition at line 330 of file qgssinglesymbolrenderer.cpp.

◆ legendSymbolItems()

QgsLegendSymbolList QgsSingleSymbolRenderer::legendSymbolItems ( ) const
overridevirtual

Returns a list of symbology items for the legend.

See also
legendKeys()

Reimplemented from QgsFeatureRenderer.

Definition at line 304 of file qgssinglesymbolrenderer.cpp.

◆ originalSymbolForFeature()

QgsSymbol * QgsSingleSymbolRenderer::originalSymbolForFeature ( const QgsFeature feature,
QgsRenderContext context 
) const
overridevirtual

Returns symbol for feature.

The difference compared to symbolForFeature() is that it returns original symbol which can be used as an identifier for renderer's rule - the former may return a temporary replacement of a symbol for use in rendering.

Reimplemented from QgsFeatureRenderer.

Definition at line 54 of file qgssinglesymbolrenderer.cpp.

◆ save()

QDomElement QgsSingleSymbolRenderer::save ( QDomDocument &  doc,
const QgsReadWriteContext context 
)
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 276 of file qgssinglesymbolrenderer.cpp.

◆ setDataDefinedSizeLegend()

void QgsSingleSymbolRenderer::setDataDefinedSizeLegend ( QgsDataDefinedSizeLegend settings)

Configures appearance of legend when renderer is configured to use data-defined size for marker symbols.

This allows configuring which values (symbol sizes) should be shown in the legend, whether to display different symbol sizes collapsed in one legend node or separated across multiple legend nodes etc.

When renderer does not use data-defined size or does not use marker symbols, these settings will be ignored. Takes ownership of the passed settings objects. nullptr is a valid input that disables data-defined size legend.

Definition at line 388 of file qgssinglesymbolrenderer.cpp.

◆ setLegendSymbolItem()

void QgsSingleSymbolRenderer::setLegendSymbolItem ( const QString &  key,
QgsSymbol symbol 
)
overridevirtual

Sets the symbol to be used for a legend symbol item.

Parameters
keyrule key for legend symbol
symbolnew symbol for legend item. Ownership is transferred to renderer.
See also
legendKeys()

Reimplemented from QgsFeatureRenderer.

Definition at line 344 of file qgssinglesymbolrenderer.cpp.

◆ setSymbol()

void QgsSingleSymbolRenderer::setSymbol ( QgsSymbol s)

Sets the symbol which will be rendered for every feature.

Ownership of the symbol is transferred to the renderer.

See also
symbol()

Definition at line 104 of file qgssinglesymbolrenderer.cpp.

◆ startRender()

void QgsSingleSymbolRenderer::startRender ( QgsRenderContext context,
const QgsFields fields 
)
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.

Parameters
contextAdditional information passed to the renderer about the job which will be rendered
fieldsThe fields available for rendering
See also
stopRender()
Warning
This method is not thread safe. Before calling startRender() in a non-main thread, the renderer should instead be cloned and startRender()/stopRender() called on the clone.

Reimplemented from QgsFeatureRenderer.

Definition at line 61 of file qgssinglesymbolrenderer.cpp.

◆ stopRender()

void QgsSingleSymbolRenderer::stopRender ( QgsRenderContext context)
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().

Warning
This method is not thread safe. Before calling startRender() in a non-main thread, the renderer should instead be cloned and startRender()/stopRender() called on the clone.
See also
startRender()

Reimplemented from QgsFeatureRenderer.

Definition at line 71 of file qgssinglesymbolrenderer.cpp.

◆ symbol()

QgsSymbol * QgsSingleSymbolRenderer::symbol ( ) const

Returns the symbol which will be rendered for every feature.

See also
setSymbol()

Definition at line 99 of file qgssinglesymbolrenderer.cpp.

◆ symbolForFeature()

QgsSymbol * QgsSingleSymbolRenderer::symbolForFeature ( const QgsFeature feature,
QgsRenderContext context 
) const
overridevirtual

To be overridden.

Must be called between startRender() and stopRender() calls.

Parameters
featurefeature
contextrender context
Returns
returns pointer to symbol or 0 if symbol was not found

Implements QgsFeatureRenderer.

Definition at line 49 of file qgssinglesymbolrenderer.cpp.

◆ symbols()

QgsSymbolList QgsSingleSymbolRenderer::symbols ( QgsRenderContext context) const
overridevirtual

Returns list of symbols used by the renderer.

Parameters
contextrender context

Reimplemented from QgsFeatureRenderer.

Definition at line 139 of file qgssinglesymbolrenderer.cpp.

◆ toSld()

void QgsSingleSymbolRenderer::toSld ( QDomDocument &  doc,
QDomElement &  element,
const QVariantMap &  props = QVariantMap() 
) const
overridevirtual

used from subclasses to create SLD Rule elements following SLD v1.1 specs

Reimplemented from QgsFeatureRenderer.

Definition at line 123 of file qgssinglesymbolrenderer.cpp.

◆ usedAttributes()

QSet< QString > QgsSingleSymbolRenderer::usedAttributes ( const QgsRenderContext context) const
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.

Returns
A set of attributes

Implements QgsFeatureRenderer.

Definition at line 81 of file qgssinglesymbolrenderer.cpp.

Member Data Documentation

◆ mDataDefinedSizeLegend

std::unique_ptr<QgsDataDefinedSizeLegend> QgsSingleSymbolRenderer::mDataDefinedSizeLegend
protected

Definition at line 118 of file qgssinglesymbolrenderer.h.

◆ mSymbol

std::unique_ptr<QgsSymbol> QgsSingleSymbolRenderer::mSymbol
protected

Definition at line 117 of file qgssinglesymbolrenderer.h.


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