QGIS API Documentation  3.16.0-Hannover (43b64b13f3)
Public Member Functions | Static Public Member Functions | List of all members
QgsPointClusterRenderer Class Reference

A renderer that automatically clusters points with the same geographic position. More...

#include <qgspointclusterrenderer.h>

Inheritance diagram for QgsPointClusterRenderer:
Inheritance graph
[legend]

Public Member Functions

 QgsPointClusterRenderer ()
 
bool accept (QgsStyleEntityVisitorInterface *visitor) const override
 Accepts the specified symbology visitor, causing it to visit all symbols associated with the renderer. More...
 
QgsPointClusterRendererclone () const override
 Create a deep copy of this renderer. More...
 
QgsMarkerSymbolclusterSymbol ()
 Returns the symbol used for rendering clustered groups (but not ownership of the symbol). More...
 
QDomElement save (QDomDocument &doc, const QgsReadWriteContext &context) override
 store renderer info to XML element More...
 
void setClusterSymbol (QgsMarkerSymbol *symbol)
 Sets the symbol for rendering clustered groups. 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...
 
QSet< QString > usedAttributes (const QgsRenderContext &context) const override
 Returns a list of attributes required by this renderer. More...
 
- Public Member Functions inherited from QgsPointDistanceRenderer
 QgsPointDistanceRenderer (const QString &rendererName, const QString &labelAttributeName=QString())
 Constructor for QgsPointDistanceRenderer. More...
 
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...
 
void checkLegendSymbolItem (const QString &key, bool state) override
 item in symbology was checked More...
 
const QgsFeatureRendererembeddedRenderer () const override
 Returns the current embedded renderer (subrenderer) for this feature 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...
 
QString labelAttributeName () const
 Returns the attribute name used for labeling points, or an empty string if no labeling will be done by the renderer. More...
 
QColor labelColor () const
 Returns the color used for for labeling points. More...
 
QFont labelFont () const
 Returns the font used for labeling points. 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...
 
double minimumLabelScale () const
 Returns the minimum map scale (i.e. More...
 
QgsSymboloriginalSymbolForFeature (const QgsFeature &feature, QgsRenderContext &context) const override
 Returns symbol for feature. 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 SIP_THROW(QgsCsException)
 Render a feature using this renderer in the given context. More...
 
void setEmbeddedRenderer (QgsFeatureRenderer *r) override
 Sets an embedded renderer (subrenderer) for this feature renderer. More...
 
void setLabelAttributeName (const QString &name)
 Sets the attribute name for labeling points. More...
 
void setLabelColor (const QColor &color)
 Sets the color to use for for labeling points. More...
 
void setLabelFont (const QFont &font)
 Sets the font used for labeling points. More...
 
void setLegendSymbolItem (const QString &key, QgsSymbol *symbol) override
 Sets the symbol to be used for a legend symbol item. More...
 
void setMinimumLabelScale (double scale)
 Sets the minimum map scale (i.e. More...
 
void setTolerance (double distance)
 Sets the tolerance distance for grouping points. More...
 
void setToleranceMapUnitScale (const QgsMapUnitScale &scale)
 Sets the map unit scale object for the distance tolerance. More...
 
void setToleranceUnit (QgsUnitTypes::RenderUnit unit)
 Sets the units for the tolerance distance. 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...
 
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...
 
QgsSymbolList symbolsForFeature (const QgsFeature &feature, QgsRenderContext &context) const override
 Returns list of symbols used for rendering the feature. More...
 
double tolerance () const
 Returns the tolerance distance for grouping points. More...
 
const QgsMapUnitScaletoleranceMapUnitScale () const
 Returns the map unit scale object for the distance tolerance. More...
 
QgsUnitTypes::RenderUnit toleranceUnit () const
 Returns the units for the tolerance distance. 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 QString dump () const
 Returns debug information about this 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...
 
QgsPaintEffectpaintEffect () const
 Returns the current paint effect for the 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 QgsPointClusterRendererconvertFromRenderer (const QgsFeatureRenderer *renderer)
 Creates a QgsPointClusterRenderer from an existing renderer. More...
 
static QgsFeatureRenderercreate (QDomElement &symbologyElem, const QgsReadWriteContext &context)
 Creates a renderer from XML element. More...
 
- Static Public Member Functions inherited from QgsFeatureRenderer
static QgsFeatureRendererdefaultRenderer (QgsWkbTypes::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, QgsWkbTypes::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 QgsPointDistanceRenderer
typedef QList< QgsPointDistanceRenderer::GroupedFeatureClusteredGroup
 A group of clustered points (ie features within the distance tolerance). More...
 
- 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...
 
- Protected Member Functions inherited from QgsPointDistanceRenderer
void drawLabels (QPointF centerPoint, QgsSymbolRenderContext &context, const QList< QPointF > &labelShifts, const ClusteredGroup &group)
 Renders the labels for a group. More...
 
- 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) SIP_THROW(QgsCsException)
 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)
 
- Protected Attributes inherited from QgsPointDistanceRenderer
QList< ClusteredGroupmClusteredGroups
 Groups of features that are considered clustered together. More...
 
bool mDrawLabels
 Whether labels should be drawn for points. This is set internally from startRender() depending on scale denominator. More...
 
QMap< QgsFeatureId, int > mGroupIndex
 Mapping of feature ID to the feature's group index. More...
 
QMap< QgsFeatureId, QgsPointXYmGroupLocations
 Mapping of feature ID to approximate group location. More...
 
QString mLabelAttributeName
 Attribute name for labeling. An empty string indicates that no labels should be rendered. More...
 
QColor mLabelColor
 Label text color. More...
 
QFont mLabelFont
 Label font. More...
 
int mLabelIndex
 Label attribute index (or -1 if none). This index is not stored, it is requested in the startRender() method. More...
 
double mMinLabelScale = 0
 Maximum scale denominator for label display. A zero value indicates no scale limitation. More...
 
std::unique_ptr< QgsFeatureRenderermRenderer
 Embedded base renderer. This can be used for rendering individual, isolated points. More...
 
QgsSpatialIndexmSpatialIndex = nullptr
 Spatial index for fast lookup of nearby points. More...
 
double mTolerance
 Distance tolerance. Points that are closer together than this distance are considered clustered. More...
 
QgsMapUnitScale mToleranceMapUnitScale
 Map unit scale for distance tolerance. More...
 
QgsUnitTypes::RenderUnit mToleranceUnit
 Unit for distance tolerance. 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
 
QgsPaintEffectmPaintEffect = nullptr
 
QString mType
 
bool mUsingSymbolLevels
 

Detailed Description

A renderer that automatically clusters points with the same geographic position.

Since
QGIS 3.0

Definition at line 31 of file qgspointclusterrenderer.h.

Constructor & Destructor Documentation

◆ QgsPointClusterRenderer()

QgsPointClusterRenderer::QgsPointClusterRenderer ( )

Definition at line 28 of file qgspointclusterrenderer.cpp.

Member Function Documentation

◆ accept()

bool QgsPointClusterRenderer::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 167 of file qgspointclusterrenderer.cpp.

◆ clone()

QgsPointClusterRenderer * QgsPointClusterRenderer::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 44 of file qgspointclusterrenderer.cpp.

◆ clusterSymbol()

QgsMarkerSymbol * QgsPointClusterRenderer::clusterSymbol ( )

Returns the symbol used for rendering clustered groups (but not ownership of the symbol).

See also
setClusterSymbol()

Definition at line 120 of file qgspointclusterrenderer.cpp.

◆ convertFromRenderer()

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

Creates a QgsPointClusterRenderer from an existing renderer.

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

Definition at line 187 of file qgspointclusterrenderer.cpp.

◆ create()

QgsFeatureRenderer * QgsPointClusterRenderer::create ( QDomElement &  symbologyElem,
const QgsReadWriteContext context 
)
static

Creates a renderer from XML element.

Definition at line 97 of file qgspointclusterrenderer.cpp.

◆ save()

QDomElement QgsPointClusterRenderer::save ( QDomDocument &  doc,
const QgsReadWriteContext context 
)
overridevirtual

store renderer info to XML element

Reimplemented from QgsFeatureRenderer.

Definition at line 125 of file qgspointclusterrenderer.cpp.

◆ setClusterSymbol()

void QgsPointClusterRenderer::setClusterSymbol ( QgsMarkerSymbol symbol)

Sets the symbol for rendering clustered groups.

Parameters
symbolnew cluster symbol. Ownership is transferred to the renderer.
See also
clusterSymbol()

Definition at line 182 of file qgspointclusterrenderer.cpp.

◆ startRender()

void QgsPointClusterRenderer::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 79 of file qgspointclusterrenderer.cpp.

◆ stopRender()

void QgsPointClusterRenderer::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 88 of file qgspointclusterrenderer.cpp.

◆ usedAttributes()

QSet< QString > QgsPointClusterRenderer::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 159 of file qgspointclusterrenderer.cpp.


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