QGIS API Documentation 3.41.0-Master (d5b93354e9c)
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Public Types | Public Member Functions | Static Public Member Functions | List of all members
QgsPointDisplacementRenderer Class Reference

A renderer that automatically displaces points with the same geographic location. More...

#include <qgspointdisplacementrenderer.h>

Inheritance diagram for QgsPointDisplacementRenderer:
Inheritance graph
[legend]

Public Types

enum  Placement { Ring , ConcentricRings , Grid }
 Placement methods for dispersing points. More...
 
- Public Types inherited from QgsPointDistanceRenderer
typedef QList< QgsPointDistanceRenderer::GroupedFeatureClusteredGroup
 A group of clustered points (ie features within the distance tolerance).
 
- 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...
 
enum class  Property : int { HeatmapRadius , HeatmapMaximum }
 Data definable properties for renderers. More...
 

Public Member Functions

 QgsPointDisplacementRenderer (const QString &labelAttributeName=QString())
 Constructor for QgsPointDisplacementRenderer.
 
bool accept (QgsStyleEntityVisitorInterface *visitor) const override
 Accepts the specified symbology visitor, causing it to visit all symbols associated with the renderer.
 
QgsMarkerSymbolcenterSymbol ()
 Returns the symbol for the center of a displacement group (but not ownership of the symbol).
 
QColor circleColor () const
 Returns the color used for drawing the displacement group circle.
 
double circleRadiusAddition () const
 Returns the factor for increasing the ring size of displacement groups.
 
double circleWidth () const
 Returns the line width for the displacement group circle in mm.
 
QgsPointDisplacementRendererclone () const override
 Create a deep copy of this renderer.
 
Qgis::FeatureRendererFlags flags () const override
 Returns flags associated with the renderer.
 
double labelDistanceFactor () const
 Returns the factor for label distance from the symbol.
 
Placement placement () const
 Returns the placement method used for dispersing the points.
 
QDomElement save (QDomDocument &doc, const QgsReadWriteContext &context) override
 Stores renderer properties to an XML element.
 
void setCenterSymbol (QgsMarkerSymbol *symbol)
 Sets the center symbol for a displacement group.
 
void setCircleColor (const QColor &color)
 Sets the color used for drawing the displacement group circle.
 
void setCircleRadiusAddition (double distance)
 Sets a factor for increasing the ring size of displacement groups.
 
void setCircleWidth (double width)
 Sets the line width for the displacement group circle.
 
void setLabelDistanceFactor (double factor)
 Sets a factor for increasing the label distances from the symbol.
 
void setPlacement (Placement placement)
 Sets the placement method used for dispersing the points.
 
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.
 
QSet< QString > usedAttributes (const QgsRenderContext &context) const override
 Returns a list of attributes required by this renderer.
 
- Public Member Functions inherited from QgsPointDistanceRenderer
 QgsPointDistanceRenderer (const QString &rendererName, const QString &labelAttributeName=QString())
 Constructor for QgsPointDistanceRenderer.
 
bool accept (QgsStyleEntityVisitorInterface *visitor) const override
 Accepts the specified symbology visitor, causing it to visit all symbols associated with the renderer.
 
QgsFeatureRenderer::Capabilities capabilities () override
 Returns details about internals of this renderer.
 
void checkLegendSymbolItem (const QString &key, bool state) override
 Sets whether the legend symbology item with the specified ley should be checked.
 
const QgsFeatureRendererembeddedRenderer () const override
 Returns the current embedded renderer (subrenderer) for this feature 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.
 
QString labelAttributeName () const
 Returns the attribute name used for labeling points, or an empty string if no labeling will be done by the renderer.
 
QColor labelColor () const
 Returns the color used for for labeling points.
 
QFont labelFont () const
 Returns the font used for labeling points.
 
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.
 
double minimumLabelScale () const
 Returns the minimum map scale (i.e.
 
QgsSymboloriginalSymbolForFeature (const QgsFeature &feature, QgsRenderContext &context) const override
 Returns symbol for feature.
 
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.
 
void setEmbeddedRenderer (QgsFeatureRenderer *r) override
 Sets an embedded renderer (subrenderer) for this feature renderer.
 
void setLabelAttributeName (const QString &name)
 Sets the attribute name for labeling points.
 
void setLabelColor (const QColor &color)
 Sets the color to use for for labeling points.
 
void setLabelFont (const QFont &font)
 Sets the font used for labeling points.
 
void setLegendSymbolItem (const QString &key, QgsSymbol *symbol) override
 Sets the symbol to be used for a legend symbol item.
 
void setMinimumLabelScale (double scale)
 Sets the minimum map scale (i.e.
 
void setTolerance (double distance)
 Sets the tolerance distance for grouping points.
 
void setToleranceMapUnitScale (const QgsMapUnitScale &scale)
 Sets the map unit scale object for the distance tolerance.
 
void setToleranceUnit (Qgis::RenderUnit unit)
 Sets the units for the tolerance distance.
 
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.
 
QgsSymbolsymbolForFeature (const QgsFeature &feature, QgsRenderContext &context) const override
 To be overridden.
 
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.
 
double tolerance () const
 Returns the tolerance distance for grouping points.
 
const QgsMapUnitScaletoleranceMapUnitScale () const
 Returns the map unit scale object for the distance tolerance.
 
Qgis::RenderUnit toleranceUnit () const
 Returns the units for the tolerance distance.
 
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 ()
 
virtual bool canSkipRender ()
 Returns true if the renderer can be entirely skipped, i.e.
 
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.
 
QgsPropertyCollectiondataDefinedProperties ()
 Returns a reference to the renderer's property collection, used for data defined overrides.
 
const QgsPropertyCollectiondataDefinedProperties () const
 Returns a reference to the renderer's property collection, used for data defined overrides.
 
virtual QString dump () const
 Returns debug information about this 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.
 
QgsPaintEffectpaintEffect () 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.
 
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 QgsPointDisplacementRendererconvertFromRenderer (const QgsFeatureRenderer *renderer)
 Creates a QgsPointDisplacementRenderer from an existing renderer.
 
static QgsFeatureRenderercreate (QDomElement &symbologyElem, const QgsReadWriteContext &context)
 Create a renderer from XML element.
 
- Static Public Member Functions inherited from QgsFeatureRenderer
static QgsFeatureRendererdefaultRenderer (Qgis::GeometryType geomType)
 Returns a new renderer - used by default in vector layers.
 
static QgsFeatureRendererload (QDomElement &symbologyElem, const QgsReadWriteContext &context)
 create a renderer from XML element
 
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.
 
static const QgsPropertiesDefinitionpropertyDefinitions ()
 Returns the symbol property definitions.
 

Additional Inherited Members

- Protected Member Functions inherited from QgsPointDistanceRenderer
void drawLabels (QPointF centerPoint, QgsSymbolRenderContext &context, const QList< QPointF > &labelShifts, const ClusteredGroup &group) const
 Renders the labels for a group.
 
- 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)
 
- Protected Attributes inherited from QgsPointDistanceRenderer
QList< ClusteredGroupmClusteredGroups
 Groups of features that are considered clustered together.
 
bool mDrawLabels
 Whether labels should be drawn for points. This is set internally from startRender() depending on scale denominator.
 
QMap< QgsFeatureId, int > mGroupIndex
 Mapping of feature ID to the feature's group index.
 
QMap< QgsFeatureId, QgsPointXYmGroupLocations
 Mapping of feature ID to approximate group location.
 
QString mLabelAttributeName
 Attribute name for labeling. An empty string indicates that no labels should be rendered.
 
QColor mLabelColor
 Label text color.
 
QFont mLabelFont
 Label font.
 
int mLabelIndex
 Label attribute index (or -1 if none). This index is not stored, it is requested in the startRender() method.
 
double mMinLabelScale = 0
 Maximum scale denominator for label display. A zero value indicates no scale limitation.
 
std::unique_ptr< QgsFeatureRenderermRenderer
 Embedded base renderer. This can be used for rendering individual, isolated points.
 
QgsSpatialIndexmSpatialIndex = nullptr
 Spatial index for fast lookup of nearby points.
 
double mTolerance
 Distance tolerance. Points that are closer together than this distance are considered clustered.
 
QgsMapUnitScale mToleranceMapUnitScale
 Map unit scale for distance tolerance.
 
Qgis::RenderUnit mToleranceUnit
 Unit for distance tolerance.
 
- 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
 
QgsPaintEffectmPaintEffect = nullptr
 
double mReferenceScale = -1.0
 
QString mType
 
bool mUsingSymbolLevels = false
 

Detailed Description

A renderer that automatically displaces points with the same geographic location.

Definition at line 30 of file qgspointdisplacementrenderer.h.

Member Enumeration Documentation

◆ Placement

Placement methods for dispersing points.

Enumerator
Ring 

Place points in a single ring around group.

ConcentricRings 

Place points in concentric rings around group.

Grid 

Place points in a grid around group.

Definition at line 37 of file qgspointdisplacementrenderer.h.

Constructor & Destructor Documentation

◆ QgsPointDisplacementRenderer()

QgsPointDisplacementRenderer::QgsPointDisplacementRenderer ( const QString &  labelAttributeName = QString())

Constructor for QgsPointDisplacementRenderer.

Parameters
labelAttributeNameoptional attribute name for labeling points

Definition at line 31 of file qgspointdisplacementrenderer.cpp.

Member Function Documentation

◆ accept()

bool QgsPointDisplacementRenderer::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 249 of file qgspointdisplacementrenderer.cpp.

◆ centerSymbol()

QgsMarkerSymbol * QgsPointDisplacementRenderer::centerSymbol ( )

Returns the symbol for the center of a displacement group (but not ownership of the symbol).

See also
setCenterSymbol()

Definition at line 203 of file qgspointdisplacementrenderer.cpp.

◆ circleColor()

QColor QgsPointDisplacementRenderer::circleColor ( ) const
inline

Returns the color used for drawing the displacement group circle.

See also
setCircleColor()
circleWidth()

Definition at line 89 of file qgspointdisplacementrenderer.h.

◆ circleRadiusAddition()

double QgsPointDisplacementRenderer::circleRadiusAddition ( ) const
inline

Returns the factor for increasing the ring size of displacement groups.

See also
setCircleRadiusAddition()

Definition at line 102 of file qgspointdisplacementrenderer.h.

◆ circleWidth()

double QgsPointDisplacementRenderer::circleWidth ( ) const
inline

Returns the line width for the displacement group circle in mm.

See also
setCircleWidth()
circleColor()

Definition at line 74 of file qgspointdisplacementrenderer.h.

◆ clone()

QgsPointDisplacementRenderer * QgsPointDisplacementRenderer::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 48 of file qgspointdisplacementrenderer.cpp.

◆ convertFromRenderer()

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

Creates a QgsPointDisplacementRenderer from an existing renderer.

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

Definition at line 480 of file qgspointdisplacementrenderer.cpp.

◆ create()

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

Create a renderer from XML element.

Definition at line 166 of file qgspointdisplacementrenderer.cpp.

◆ flags()

Qgis::FeatureRendererFlags QgsPointDisplacementRenderer::flags ( ) const
overridevirtual

Returns flags associated with the renderer.

Since
QGIS 3.40

Reimplemented from QgsFeatureRenderer.

Definition at line 38 of file qgspointdisplacementrenderer.cpp.

◆ labelDistanceFactor()

double QgsPointDisplacementRenderer::labelDistanceFactor ( ) const
inline

Returns the factor for label distance from the symbol.

See also
setLabelDistanceFactor()
Since
QGIS 3.8

Definition at line 117 of file qgspointdisplacementrenderer.h.

◆ placement()

Placement QgsPointDisplacementRenderer::placement ( ) const
inline

Returns the placement method used for dispersing the points.

See also
setPlacement()

Definition at line 123 of file qgspointdisplacementrenderer.h.

◆ save()

QDomElement QgsPointDisplacementRenderer::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 208 of file qgspointdisplacementrenderer.cpp.

◆ setCenterSymbol()

void QgsPointDisplacementRenderer::setCenterSymbol ( QgsMarkerSymbol symbol)

Sets the center symbol for a displacement group.

Parameters
symbolnew center symbol. Ownership is transferred to the renderer.
See also
centerSymbol()

Definition at line 264 of file qgspointdisplacementrenderer.cpp.

◆ setCircleColor()

void QgsPointDisplacementRenderer::setCircleColor ( const QColor &  color)
inline

Sets the color used for drawing the displacement group circle.

Parameters
colorcircle color
See also
circleColor()
setCircleWidth()

Definition at line 82 of file qgspointdisplacementrenderer.h.

◆ setCircleRadiusAddition()

void QgsPointDisplacementRenderer::setCircleRadiusAddition ( double  distance)
inline

Sets a factor for increasing the ring size of displacement groups.

Parameters
distanceaddition factor
See also
circleRadiusAddition()

Definition at line 96 of file qgspointdisplacementrenderer.h.

◆ setCircleWidth()

void QgsPointDisplacementRenderer::setCircleWidth ( double  width)
inline

Sets the line width for the displacement group circle.

Parameters
widthline width in mm
See also
circleWidth()
setCircleColor()

Definition at line 67 of file qgspointdisplacementrenderer.h.

◆ setLabelDistanceFactor()

void QgsPointDisplacementRenderer::setLabelDistanceFactor ( double  factor)
inline

Sets a factor for increasing the label distances from the symbol.

Parameters
factoraddition factor
See also
labelDistanceFactor()
Since
QGIS 3.8

Definition at line 110 of file qgspointdisplacementrenderer.h.

◆ setPlacement()

void QgsPointDisplacementRenderer::setPlacement ( Placement  placement)
inline

Sets the placement method used for dispersing the points.

Parameters
placementplacement method
See also
placement()

Definition at line 130 of file qgspointdisplacementrenderer.h.

◆ startRender()

void QgsPointDisplacementRenderer::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 147 of file qgspointdisplacementrenderer.cpp.

◆ stopRender()

void QgsPointDisplacementRenderer::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 157 of file qgspointdisplacementrenderer.cpp.

◆ usedAttributes()

QSet< QString > QgsPointDisplacementRenderer::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 241 of file qgspointdisplacementrenderer.cpp.


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