QGIS API Documentation  2.18.3-Las Palmas (77b8c3d)
Public Member Functions | Static Public Member Functions | List of all members
QgsNullSymbolRenderer Class Reference

Null symbol renderer. More...

#include <qgsnullsymbolrenderer.h>

Inheritance diagram for QgsNullSymbolRenderer:
Inheritance graph
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Public Member Functions

 QgsNullSymbolRenderer ()
 
virtual ~QgsNullSymbolRenderer ()
 
virtual QgsFeatureRendererV2clone () const override
 
virtual QString dump () const override
 for debugging More...
 
virtual QgsSymbolV2originalSymbolForFeature (QgsFeature &feature, QgsRenderContext &context) override
 Return symbol for feature. More...
 
virtual bool renderFeature (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...
 
virtual QDomElement save (QDomDocument &doc) override
 store renderer info to XML element More...
 
virtual void startRender (QgsRenderContext &context, const QgsFields &fields) override
 Needs to be called when a new render cycle is started. More...
 
virtual void stopRender (QgsRenderContext &context) override
 Needs to be called when a render cycle has finished to clean up. More...
 
virtual QgsSymbolV2symbolForFeature (QgsFeature &feature, QgsRenderContext &context) override
 To be overridden. More...
 
virtual QgsSymbolV2List symbols (QgsRenderContext &context) override
 Returns list of symbols used by the renderer. More...
 
virtual QList< QStringusedAttributes () override
 Returns a set of attributes required for this renderer. More...
 
virtual bool willRenderFeature (QgsFeature &feat, QgsRenderContext &context) override
 Returns whether the renderer will render a feature or not. More...
 
- Public Member Functions inherited from QgsFeatureRendererV2
virtual ~QgsFeatureRendererV2 ()
 
virtual int capabilities ()
 returns bitwise OR-ed capabilities of the renderer More...
 
virtual void checkLegendSymbolItem (const QString &key, bool state=true)
 item in symbology was checked More...
 
virtual const QgsFeatureRendererV2embeddedRenderer () 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...
 
virtual QSet< QStringlegendKeysForFeature (QgsFeature &feature, QgsRenderContext &context)
 Return legend keys matching a specified feature. More...
 
virtual bool legendSymbolItemChecked (const QString &key)
 items of symbology items in legend is checked More...
 
virtual QgsLegendSymbolList legendSymbolItems (double scaleDenominator=-1, const QString &rule="")
 return a list of item text / symbol More...
 
virtual bool legendSymbolItemsCheckable () const
 items of symbology items in legend should be checkable More...
 
virtual QgsLegendSymbolListV2 legendSymbolItemsV2 () const
 Return a list of symbology items for the legend. More...
 
virtual QgsLegendSymbologyList legendSymbologyItems (QSize iconSize)
 return a list of symbology items for the 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
 Get 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 Q_DECL_DEPRECATED QgsSymbolV2originalSymbolForFeature (QgsFeature &feature)
 Return symbol for feature. More...
 
virtual Q_DECL_DEPRECATED QgsSymbolV2List originalSymbolsForFeature (QgsFeature &feat)
 Equivalent of originalSymbolsForFeature() call extended to support renderers that may use more symbols per feature - similar to symbolsForFeature() More...
 
virtual QgsSymbolV2List originalSymbolsForFeature (QgsFeature &feat, QgsRenderContext &context)
 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...
 
virtual Q_DECL_DEPRECATED QString rotationField () const
 return rotation field name (or empty string if not set or not supported by renderer) More...
 
virtual void setEmbeddedRenderer (QgsFeatureRendererV2 *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, QgsSymbolV2 *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...
 
virtual Q_DECL_DEPRECATED void setRotationField (const QString &fieldName)
 sets rotation field of renderer (if supported by the renderer) More...
 
void setUsingSymbolLevels (bool usingSymbolLevels)
 
void setVertexMarkerAppearance (int type, int size)
 set type and size of editing vertex markers for subsequent rendering More...
 
virtual Q_DECL_DEPRECATED void startRender (QgsRenderContext &context, const QgsVectorLayer *vlayer)
 
virtual Q_DECL_DEPRECATED QgsSymbolV2symbolForFeature (QgsFeature &feature)
 To be overridden. More...
 
virtual Q_DECL_DEPRECATED QgsSymbolV2List symbols ()
 For symbol levels. More...
 
virtual Q_DECL_DEPRECATED QgsSymbolV2List symbolsForFeature (QgsFeature &feat)
 Returns list of symbols used for rendering the feature. More...
 
virtual QgsSymbolV2List symbolsForFeature (QgsFeature &feat, QgsRenderContext &context)
 Returns list of symbols used for rendering the feature. More...
 
virtual void toSld (QDomDocument &doc, QDomElement &element) const
 used from subclasses to create SLD Rule elements following SLD v1.1 specs More...
 
virtual void toSld (QDomDocument &doc, QDomElement &element, const QgsStringMap &props) const
 used from subclasses to create SLD Rule elements following SLD v1.1 specs More...
 
QString type () const
 
bool usingSymbolLevels () const
 
virtual Q_DECL_DEPRECATED bool willRenderFeature (QgsFeature &feat)
 Returns whether the renderer will render a feature or not. More...
 
virtual Q_DECL_DEPRECATED QDomElement writeSld (QDomDocument &doc, const QgsVectorLayer &layer) const
 create the SLD UserStyle element following the SLD v1.1 specs More...
 
virtual QDomElement writeSld (QDomDocument &doc, const QString &styleName) const
 create the SLD UserStyle element following the SLD v1.1 specs with the given name More...
 
virtual QDomElement writeSld (QDomDocument &doc, const QString &styleName, const QgsStringMap &props) const
 create the SLD UserStyle element following the SLD v1.1 specs with the given name More...
 

Static Public Member Functions

static QgsNullSymbolRendererconvertFromRenderer (const QgsFeatureRendererV2 *renderer)
 Creates a QgsNullSymbolRenderer from an existing renderer. More...
 
static QgsFeatureRendererV2create (QDomElement &element)
 Creates a null renderer from XML element. More...
 
- Static Public Member Functions inherited from QgsFeatureRendererV2
static QgsFeatureRendererV2defaultRenderer (QGis::GeometryType geomType)
 return a new renderer - used by default in vector layers More...
 
static QgsFeatureRendererV2load (QDomElement &symbologyElem)
 create a renderer from XML element More...
 
static QgsFeatureRendererV2loadSld (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...
 

Additional Inherited Members

- Public Types inherited from QgsFeatureRendererV2
enum  Capabilities {
  SymbolLevels = 1, RotationField = 1 << 1, MoreSymbolsPerFeature = 1 << 2, Filter = 1 << 3,
  ScaleDependent = 1 << 4
}
 
- Protected Member Functions inherited from QgsFeatureRendererV2
 QgsFeatureRendererV2 (const QString &type)
 
Q_DECL_DEPRECATED void copyPaintEffect (QgsFeatureRendererV2 *destRenderer) const
 Copies paint effect of this renderer to another renderer. More...
 
void copyRendererData (QgsFeatureRendererV2 *destRenderer) const
 Clones generic renderer data to another renderer. More...
 
void renderFeatureWithSymbol (QgsFeature &feature, QgsSymbolV2 *symbol, QgsRenderContext &context, int layer, bool selected, bool drawVertexMarker)
 
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 setScaleMethodToSymbol (QgsSymbolV2 *symbol, int scaleMethod)
 
- Static Protected Member Functions inherited from QgsFeatureRendererV2
static QgsConstWkbPtr _getLineString (QPolygonF &pts, QgsRenderContext &context, QgsConstWkbPtr &wkb, bool clipToExtent=true)
 Creates a line string in screen coordinates from a wkb string in map coordinates. More...
 
static QgsConstWkbPtr _getPoint (QPointF &pt, QgsRenderContext &context, QgsConstWkbPtr &wkb)
 Creates a point in screen coordinates from a wkb string in map coordinates. More...
 
static QgsConstWkbPtr _getPolygon (QPolygonF &pts, QList< QPolygonF > &holes, QgsRenderContext &context, QgsConstWkbPtr &wkb, bool clipToExtent=true)
 Creates a polygon in screen coordinates from a wkb string in map coordinates. More...
 
static void convertSymbolRotation (QgsSymbolV2 *symbol, const QString &field)
 
static void convertSymbolSizeScale (QgsSymbolV2 *symbol, QgsSymbolV2::ScaleMethod method, const QString &field)
 
- Protected Attributes inherited from QgsFeatureRendererV2
int mCurrentVertexMarkerSize
 The current size of editing marker. More...
 
int mCurrentVertexMarkerType
 The current type of editing marker. More...
 
bool mForceRaster
 
QgsFeatureRequest::OrderBy mOrderBy
 
bool mOrderByEnabled
 
QgsPaintEffectmPaintEffect
 
QString mType
 
bool mUsingSymbolLevels
 

Detailed Description

Null symbol renderer.

Renderer which draws no symbols for features by default, but allows for labeling and diagrams for the layer. Selected features will also be drawn with a default symbol.

Note
Added in version 2.16

Definition at line 29 of file qgsnullsymbolrenderer.h.

Constructor & Destructor Documentation

QgsNullSymbolRenderer::QgsNullSymbolRenderer ( )

Definition at line 22 of file qgsnullsymbolrenderer.cpp.

QgsNullSymbolRenderer::~QgsNullSymbolRenderer ( )
virtual

Definition at line 27 of file qgsnullsymbolrenderer.cpp.

Member Function Documentation

QgsFeatureRendererV2 * QgsNullSymbolRenderer::clone ( ) const
overridevirtual

Implements QgsFeatureRendererV2.

Definition at line 96 of file qgsnullsymbolrenderer.cpp.

QgsNullSymbolRenderer * QgsNullSymbolRenderer::convertFromRenderer ( const QgsFeatureRendererV2 renderer)
static

Creates a QgsNullSymbolRenderer from an existing renderer.

Parameters
rendererrenderer to convert from
Returns
a new renderer if the conversion was possible, otherwise nullptr.

Definition at line 121 of file qgsnullsymbolrenderer.cpp.

QgsFeatureRendererV2 * QgsNullSymbolRenderer::create ( QDomElement element)
static

Creates a null renderer from XML element.

Parameters
elementDOM element
Returns
new null symbol renderer

Definition at line 107 of file qgsnullsymbolrenderer.cpp.

QString QgsNullSymbolRenderer::dump ( ) const
overridevirtual

for debugging

Reimplemented from QgsFeatureRendererV2.

Definition at line 91 of file qgsnullsymbolrenderer.cpp.

QgsSymbolV2 * QgsNullSymbolRenderer::originalSymbolForFeature ( QgsFeature feature,
QgsRenderContext context 
)
overridevirtual

Return 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.

Note
added in 2.12
available in Python bindings as originalSymbolForFeature2

Reimplemented from QgsFeatureRendererV2.

Definition at line 36 of file qgsnullsymbolrenderer.cpp.

bool QgsNullSymbolRenderer::renderFeature ( QgsFeature feature,
QgsRenderContext context,
int  layer = -1,
bool  selected = false,
bool  drawVertexMarker = false 
)
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 QgsFeatureRendererV2.

Definition at line 41 of file qgsnullsymbolrenderer.cpp.

QDomElement QgsNullSymbolRenderer::save ( QDomDocument doc)
overridevirtual

store renderer info to XML element

Reimplemented from QgsFeatureRendererV2.

Definition at line 114 of file qgsnullsymbolrenderer.cpp.

void QgsNullSymbolRenderer::startRender ( QgsRenderContext context,
const QgsFields fields 
)
overridevirtual

Needs to be called when a new render cycle is started.

Parameters
contextAdditional information passed to the renderer about the job which will be rendered
fieldsThe fields available for rendering
Returns
Information passed back from the renderer that can e.g. be used to reduce the amount of requested features

Implements QgsFeatureRendererV2.

Definition at line 66 of file qgsnullsymbolrenderer.cpp.

void QgsNullSymbolRenderer::stopRender ( QgsRenderContext context)
overridevirtual

Needs to be called when a render cycle has finished to clean up.

Implements QgsFeatureRendererV2.

Definition at line 72 of file qgsnullsymbolrenderer.cpp.

QgsSymbolV2 * QgsNullSymbolRenderer::symbolForFeature ( QgsFeature feature,
QgsRenderContext context 
)
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
Note
added in QGIS 2.12
available in Python bindings as symbolForFeature2

Reimplemented from QgsFeatureRendererV2.

Definition at line 31 of file qgsnullsymbolrenderer.cpp.

QgsSymbolV2List QgsNullSymbolRenderer::symbols ( QgsRenderContext context)
overridevirtual

Returns list of symbols used by the renderer.

Parameters
contextrender context
Note
added in QGIS 2.12
available in Python bindings as symbols2

Reimplemented from QgsFeatureRendererV2.

Definition at line 102 of file qgsnullsymbolrenderer.cpp.

QList< QString > QgsNullSymbolRenderer::usedAttributes ( )
overridevirtual

Returns a set of attributes required for this renderer.

TODO QGIS3: Change QList to QSet

Implements QgsFeatureRendererV2.

Definition at line 86 of file qgsnullsymbolrenderer.cpp.

bool QgsNullSymbolRenderer::willRenderFeature ( QgsFeature feat,
QgsRenderContext context 
)
overridevirtual

Returns whether the renderer will render a feature or not.

Must be called between startRender() and stopRender() calls. Default implementation uses symbolForFeature().

Note
added in QGIS 2.12
available in Python bindings as willRenderFeature2

Reimplemented from QgsFeatureRendererV2.

Definition at line 80 of file qgsnullsymbolrenderer.cpp.


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