QGIS API Documentation
3.0.2-Girona (307d082)
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An abstract base class for distance based point renderers (e.g., clusterer and displacement renderers). More...
#include <qgspointdistancerenderer.h>
Classes | |
struct | GroupedFeature |
Contains properties for a feature within a clustered group. More... | |
Public Types | |
typedef QList< QgsPointDistanceRenderer::GroupedFeature > | ClusteredGroup |
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... | |
Public Member Functions | |
QgsPointDistanceRenderer (const QString &rendererName, const QString &labelAttributeName=QString()) | |
Constructor for QgsPointDistanceRenderer. 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 QgsFeatureRenderer * | embeddedRenderer () 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... | |
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 (QgsFeature &feature, QgsRenderContext &context) override |
Return 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... | |
QgsSymbol * | originalSymbolForFeature (QgsFeature &feat, QgsRenderContext &context) override |
Return symbol for feature. More... | |
QgsSymbolList | originalSymbolsForFeature (QgsFeature &feat, QgsRenderContext &context) override |
Equivalent of originalSymbolsForFeature() call extended to support renderers that may use more symbols per feature - similar to symbolsForFeature() More... | |
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... | |
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... | |
QgsSymbol * | symbolForFeature (QgsFeature &feature, QgsRenderContext &context) override |
To be overridden. More... | |
QgsSymbolList | symbols (QgsRenderContext &context) override |
Returns list of symbols used by the renderer. More... | |
QgsSymbolList | symbolsForFeature (QgsFeature &feat, QgsRenderContext &context) override |
Returns list of symbols used for rendering the feature. More... | |
double | tolerance () const |
Returns the tolerance distance for grouping points. More... | |
const QgsMapUnitScale & | toleranceMapUnitScale () 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 |
Return a list of attributes required by this renderer. More... | |
bool | willRenderFeature (QgsFeature &feat, QgsRenderContext &context) override |
Returns whether the renderer will render a feature or not. More... | |
Public Member Functions inherited from QgsFeatureRenderer | |
virtual | ~QgsFeatureRenderer () |
virtual QgsFeatureRenderer * | clone () const =0 |
Create a deep copy of this renderer. More... | |
virtual QString | dump () const |
Returns debug information about this renderer. 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 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... | |
QgsPaintEffect * | paintEffect () const |
Returns the current paint effect for the renderer. More... | |
virtual QDomElement | save (QDomDocument &doc, const QgsReadWriteContext &context) |
store renderer info to XML element 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, int size) |
set 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... | |
Protected Member Functions | |
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 (QgsFeature &feature, QgsSymbol *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... | |
Protected Attributes | |
QList< ClusteredGroup > | mClusteredGroups |
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, QgsPointXY > | mGroupLocations |
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< QgsFeatureRenderer > | mRenderer |
Embedded base renderer. This can be used for rendering individual, isolated points. More... | |
QgsSpatialIndex * | mSpatialIndex = 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 | |
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 |
QgsPaintEffect * | mPaintEffect = nullptr |
QString | mType |
bool | mUsingSymbolLevels |
Additional Inherited Members | |
Static Public Member Functions inherited from QgsFeatureRenderer | |
static QgsFeatureRenderer * | defaultRenderer (QgsWkbTypes::GeometryType geomType) |
return 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... | |
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) |
An abstract base class for distance based point renderers (e.g., clusterer and displacement renderers).
QgsPointDistanceRenderer handles calculation of point clusters using a distance based threshold. Subclasses must implement drawGroup() to handle the rendering of individual point clusters in the desired style.
Definition at line 38 of file qgspointdistancerenderer.h.
A group of clustered points (ie features within the distance tolerance).
Definition at line 77 of file qgspointdistancerenderer.h.
QgsPointDistanceRenderer::QgsPointDistanceRenderer | ( | const QString & | rendererName, |
const QString & | labelAttributeName = QString() |
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Constructor for QgsPointDistanceRenderer.
rendererName | name of renderer for registry |
labelAttributeName | optional attribute for labeling points |
Definition at line 30 of file qgspointdistancerenderer.cpp.
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Returns details about internals of this renderer.
E.g. if you only want to deal with visible features:
Reimplemented from QgsFeatureRenderer.
Definition at line 221 of file qgspointdistancerenderer.cpp.
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item in symbology was checked
Reimplemented from QgsFeatureRenderer.
Definition at line 191 of file qgspointdistancerenderer.cpp.
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Renders the labels for a group.
centerPoint | center point of group |
context | destination render context |
labelShifts | displacement for individual label positions |
group | group of clustered features to label |
Definition at line 379 of file qgspointdistancerenderer.cpp.
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Returns the current embedded renderer (subrenderer) for this feature renderer.
The base class implementation does not use subrenderers and will always return null.
Reimplemented from QgsFeatureRenderer.
Definition at line 162 of file qgspointdistancerenderer.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 199 of file qgspointdistancerenderer.cpp.
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Returns the attribute name used for labeling points, or an empty string if no labeling will be done by the renderer.
Definition at line 126 of file qgspointdistancerenderer.h.
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Returns the color used for for labeling points.
Definition at line 176 of file qgspointdistancerenderer.h.
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Returns the font used for labeling points.
Definition at line 143 of file qgspointdistancerenderer.h.
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Return legend keys matching a specified feature.
Reimplemented from QgsFeatureRenderer.
Definition at line 271 of file qgspointdistancerenderer.cpp.
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items of symbology items in legend is checked
Reimplemented from QgsFeatureRenderer.
Definition at line 183 of file qgspointdistancerenderer.cpp.
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Returns a list of symbology items for the legend.
Reimplemented from QgsFeatureRenderer.
Definition at line 338 of file qgspointdistancerenderer.cpp.
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items of symbology items in legend should be checkable
Reimplemented from QgsFeatureRenderer.
Definition at line 175 of file qgspointdistancerenderer.cpp.
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Returns the minimum map scale (i.e.
most "zoomed out") at which points should be labeled by the renderer. The scale value indicates the scale denominator, e.g. 1000.0 for a 1:1000 map.
Definition at line 159 of file qgspointdistancerenderer.h.
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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.
Reimplemented from QgsFeatureRenderer.
Definition at line 248 of file qgspointdistancerenderer.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 264 of file qgspointdistancerenderer.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 48 of file qgspointdistancerenderer.cpp.
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Sets an embedded renderer (subrenderer) for this feature renderer.
The base class implementation does nothing with subrenderers, but individual derived classes can use these to modify their behavior.
subRenderer | the embedded renderer. Ownership will be transferred. |
Reimplemented from QgsFeatureRenderer.
Definition at line 157 of file qgspointdistancerenderer.cpp.
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Sets the attribute name for labeling points.
name | attribute name, or empty string to avoid labeling features by the renderer |
Definition at line 116 of file qgspointdistancerenderer.h.
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Sets the color to use for for labeling points.
color | label color |
Definition at line 168 of file qgspointdistancerenderer.h.
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Sets the font used for labeling points.
font | label font |
Definition at line 135 of file qgspointdistancerenderer.h.
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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 167 of file qgspointdistancerenderer.cpp.
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Sets the minimum map scale (i.e.
most "zoomed out") at which points should be labeled by the renderer. The scale value indicates the scale denominator, e.g. 1000.0 for a 1:1000 map.
Definition at line 151 of file qgspointdistancerenderer.h.
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Sets the tolerance distance for grouping points.
Units are specified using setToleranceUnit().
distance | tolerance distance |
Definition at line 185 of file qgspointdistancerenderer.h.
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Sets the map unit scale object for the distance tolerance.
This is only used if the toleranceUnit() is set to QgsUnitTypes::RenderMapUnits.
scale | scale for distance tolerance |
Definition at line 219 of file qgspointdistancerenderer.h.
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Sets the units for the tolerance distance.
unit | tolerance distance units |
Definition at line 202 of file qgspointdistancerenderer.h.
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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 288 of file qgspointdistancerenderer.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 318 of file qgspointdistancerenderer.cpp.
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To be overridden.
Must be called between startRender() and stopRender() calls.
feature | feature |
context | render context |
Implements QgsFeatureRenderer.
Definition at line 239 of file qgspointdistancerenderer.cpp.
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Returns list of symbols used by the renderer.
context | render context |
Reimplemented from QgsFeatureRenderer.
Definition at line 230 of file qgspointdistancerenderer.cpp.
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overridevirtual |
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 255 of file qgspointdistancerenderer.cpp.
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Returns the tolerance distance for grouping points.
Units are retrieved using toleranceUnit().
Definition at line 193 of file qgspointdistancerenderer.h.
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Returns the map unit scale object for the distance tolerance.
This is only used if the toleranceUnit() is set to QgsUnitTypes::RenderMapUnits.
Definition at line 227 of file qgspointdistancerenderer.h.
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Returns the units for the tolerance distance.
Definition at line 210 of file qgspointdistancerenderer.h.
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used from subclasses to create SLD Rule elements following SLD v1.1 specs
Reimplemented from QgsFeatureRenderer.
Definition at line 42 of file qgspointdistancerenderer.cpp.
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overridevirtual |
Return 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 207 of file qgspointdistancerenderer.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 278 of file qgspointdistancerenderer.cpp.
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Groups of features that are considered clustered together.
Definition at line 257 of file qgspointdistancerenderer.h.
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Whether labels should be drawn for points. This is set internally from startRender() depending on scale denominator.
Definition at line 252 of file qgspointdistancerenderer.h.
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Mapping of feature ID to the feature's group index.
Definition at line 260 of file qgspointdistancerenderer.h.
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Mapping of feature ID to approximate group location.
Definition at line 263 of file qgspointdistancerenderer.h.
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Attribute name for labeling. An empty string indicates that no labels should be rendered.
Definition at line 235 of file qgspointdistancerenderer.h.
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Label text color.
Definition at line 250 of file qgspointdistancerenderer.h.
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Label font.
Definition at line 248 of file qgspointdistancerenderer.h.
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Label attribute index (or -1 if none). This index is not stored, it is requested in the startRender() method.
Definition at line 238 of file qgspointdistancerenderer.h.
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Maximum scale denominator for label display. A zero value indicates no scale limitation.
Definition at line 254 of file qgspointdistancerenderer.h.
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Embedded base renderer. This can be used for rendering individual, isolated points.
Definition at line 232 of file qgspointdistancerenderer.h.
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Spatial index for fast lookup of nearby points.
Definition at line 266 of file qgspointdistancerenderer.h.
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Distance tolerance. Points that are closer together than this distance are considered clustered.
Definition at line 241 of file qgspointdistancerenderer.h.
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Map unit scale for distance tolerance.
Definition at line 245 of file qgspointdistancerenderer.h.
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Unit for distance tolerance.
Definition at line 243 of file qgspointdistancerenderer.h.