A renderer which draws points as a live heatmap. More...

#include <qgsheatmaprenderer.h>

Inheritance diagram for QgsHeatmapRenderer:

Public Member Functions
	QgsHeatmapRenderer ()

virtual	~QgsHeatmapRenderer ()

virtual QgsHeatmapRenderer *	clone () const override

QgsVectorColorRampV2 *	colorRamp () const
	Returns the color ramp used for shading the heatmap. More...

virtual QString	dump () const override
	for debugging More...

bool	invertRamp () const
	Returns whether the ramp is inverted. More...

double	maximumValue () const
	Returns the maximum value used for shading the heatmap. More...

virtual void	modifyRequestExtent (QgsRectangle &extent, QgsRenderContext &context) override
	Allows for a renderer to modify the extent of a feature request prior to rendering. More...

double	radius () const
	Returns the radius for the heatmap. More...

const QgsMapUnitScale &	radiusMapUnitScale () const
	Returns the map unit scale used for the heatmap's radius. More...

QgsSymbolV2::OutputUnit	radiusUnit () const
	Returns the units used for the heatmap's radius. 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...

double	renderQuality () const
	Returns the render quality used for drawing the heatmap. More...

virtual QDomElement	save (QDomDocument &doc) override
	store renderer info to XML element More...

void	setColorRamp (QgsVectorColorRampV2 *ramp)
	Sets the color ramp to use for shading the heatmap. More...

void	setInvertRamp (const bool invert)
	Sets whether the ramp is inverted. More...

void	setMaximumValue (const double value)
	Sets the maximum value used for shading the heatmap. More...

void	setRadius (const double radius)
	Sets the radius for the heatmap. More...

void	setRadiusMapUnitScale (const QgsMapUnitScale &scale)
	Sets the map unit scale used for the heatmap's radius. More...

void	setRadiusUnit (const QgsSymbolV2::OutputUnit unit)
	Sets the units used for the heatmap's radius. More...

void	setRenderQuality (const int quality)
	Sets the render quality used for drawing the heatmap. More...

void	setWeightExpression (const QString &expression)
	Sets the expression used for weighting points when generating the heatmap. 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 QgsSymbolV2 *	symbolForFeature (QgsFeature &feature, QgsRenderContext &context) override

virtual QgsSymbolV2List	symbols (QgsRenderContext &context) override

virtual QList< QString >	usedAttributes () override
	Returns a set of attributes required for this renderer. More...

QString	weightExpression () const
	Returns the expression used for weighting points when generating the heatmap. 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 QgsFeatureRendererV2 *	embeddedRenderer () 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< QString >	legendKeysForFeature (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...

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 QgsSymbolV2 *	originalSymbolForFeature (QgsFeature &feature)
	Return symbol for feature. More...

virtual QgsSymbolV2 *	originalSymbolForFeature (QgsFeature &feature, QgsRenderContext &context)
	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...

QgsPaintEffect *	paintEffect () 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 QgsSymbolV2 *	symbolForFeature (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 bool	willRenderFeature (QgsFeature &feat, QgsRenderContext &context)
	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 QgsHeatmapRenderer *	convertFromRenderer (const QgsFeatureRendererV2 *renderer)

static QgsFeatureRendererV2 *	create (QDomElement &element)

Static Public Member Functions inherited from QgsFeatureRendererV2
static QgsFeatureRendererV2 *	defaultRenderer (QGis::GeometryType geomType)
	return a new renderer - used by default in vector layers More...

static QgsFeatureRendererV2 *	load (QDomElement &symbologyElem)
	create a renderer from XML element More...

static QgsFeatureRendererV2 *	loadSld (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

QgsPaintEffect *	mPaintEffect

QString	mType

bool	mUsingSymbolLevels

Detailed Description

A renderer which draws points as a live heatmap.

Note: Added in version 2.7

Definition at line 33 of file qgsheatmaprenderer.h.

Constructor & Destructor Documentation

◆ QgsHeatmapRenderer()

QgsHeatmapRenderer::QgsHeatmapRenderer ( )

Definition at line 34 of file qgsheatmaprenderer.cpp.

◆ ~QgsHeatmapRenderer()

QgsHeatmapRenderer::~QgsHeatmapRenderer ( )

virtual

Definition at line 52 of file qgsheatmaprenderer.cpp.

Member Function Documentation

◆ clone()

QgsHeatmapRenderer * QgsHeatmapRenderer::clone ( ) const

overridevirtual

Implements QgsFeatureRendererV2.

Definition at line 286 of file qgsheatmaprenderer.cpp.

◆ colorRamp()

QgsVectorColorRampV2* QgsHeatmapRenderer::colorRamp ( ) const

inline

Returns the color ramp used for shading the heatmap.

Returns: color ramp for heatmap

See also: setColorRamp

Definition at line 65 of file qgsheatmaprenderer.h.

◆ convertFromRenderer()

QgsHeatmapRenderer * QgsHeatmapRenderer::convertFromRenderer ( const QgsFeatureRendererV2 * renderer )

static

Definition at line 408 of file qgsheatmaprenderer.cpp.

◆ create()

QgsFeatureRendererV2 * QgsHeatmapRenderer::create ( QDomElement & element )

static

Definition at line 329 of file qgsheatmaprenderer.cpp.

◆ dump()

QString QgsHeatmapRenderer::dump ( ) const

overridevirtual

for debugging

Reimplemented from QgsFeatureRendererV2.

Definition at line 281 of file qgsheatmaprenderer.cpp.

◆ invertRamp()

bool QgsHeatmapRenderer::invertRamp ( ) const

inline

Returns whether the ramp is inverted.

Returns: true if color ramp is inverted

See also: setInvertRamp; colorRamp

Definition at line 77 of file qgsheatmaprenderer.h.

◆ maximumValue()

double QgsHeatmapRenderer::maximumValue ( ) const

inline

Returns the maximum value used for shading the heatmap.

Returns: maximum value for heatmap shading. If 0, then maximum value will be automatically calculated.

See also: setMaximumValue

Definition at line 136 of file qgsheatmaprenderer.h.

◆ modifyRequestExtent()

void QgsHeatmapRenderer::modifyRequestExtent	(	QgsRectangle &	extent,
		QgsRenderContext &	context
	)

overridevirtual

Allows for a renderer to modify the extent of a feature request prior to rendering.

Parameters

extent	reference to request's filter extent. Modify extent to change the extent of feature request
context	render context

Note: added in QGIS 2.7

Reimplemented from QgsFeatureRendererV2.

Definition at line 305 of file qgsheatmaprenderer.cpp.

◆ radius()

double QgsHeatmapRenderer::radius ( ) const

inline

Returns the radius for the heatmap.

Returns: heatmap radius

See also: setRadius; radiusUnit; radiusMapUnitScale

Definition at line 92 of file qgsheatmaprenderer.h.

◆ radiusMapUnitScale()

const QgsMapUnitScale& QgsHeatmapRenderer::radiusMapUnitScale ( ) const

inline

Returns the map unit scale used for the heatmap's radius.

Returns: map unit scale for heatmap's radius

See also: radius; radiusUnit; setRadiusMapUnitScale

Definition at line 122 of file qgsheatmaprenderer.h.

◆ radiusUnit()

QgsSymbolV2::OutputUnit QgsHeatmapRenderer::radiusUnit ( ) const

inline

Returns the units used for the heatmap's radius.

Returns: units for heatmap radius

See also: radius; setRadiusUnit; radiusMapUnitScale

Definition at line 107 of file qgsheatmaprenderer.h.

◆ renderFeature()

bool QgsHeatmapRenderer::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 102 of file qgsheatmaprenderer.cpp.

◆ renderQuality()

double QgsHeatmapRenderer::renderQuality ( ) const

inline

Returns the render quality used for drawing the heatmap.

Returns: render quality. A value of 1 indicates maximum quality, and increasing the value will result in faster drawing but lower quality rendering.

See also: setRenderQuality

Definition at line 149 of file qgsheatmaprenderer.h.

◆ save()

QDomElement QgsHeatmapRenderer::save ( QDomDocument & doc )

overridevirtual

store renderer info to XML element

Reimplemented from QgsFeatureRendererV2.

Definition at line 348 of file qgsheatmaprenderer.cpp.

◆ setColorRamp()

void QgsHeatmapRenderer::setColorRamp ( QgsVectorColorRampV2 * ramp )

Sets the color ramp to use for shading the heatmap.

Parameters

ramp	color ramp for heatmap. Ownership of ramp is transferred to the renderer.

See also: colorRamp

Definition at line 420 of file qgsheatmaprenderer.cpp.

◆ setInvertRamp()

void QgsHeatmapRenderer::setInvertRamp ( const bool invert )

inline

Sets whether the ramp is inverted.

Parameters

invert set to true to invert color ramp

See also: invertRamp; setColorRamp

Definition at line 84 of file qgsheatmaprenderer.h.

◆ setMaximumValue()

void QgsHeatmapRenderer::setMaximumValue ( const double value )

inline

Sets the maximum value used for shading the heatmap.

Parameters

value maximum value for heatmap shading. Set to 0 for automatic calculation of maximum value.

See also: maximumValue

Definition at line 142 of file qgsheatmaprenderer.h.

◆ setRadius()

void QgsHeatmapRenderer::setRadius ( const double radius )

inline

Sets the radius for the heatmap.

Parameters

radius heatmap radius

See also: radius; setRadiusUnit; setRadiusMapUnitScale

Definition at line 99 of file qgsheatmaprenderer.h.

◆ setRadiusMapUnitScale()

void QgsHeatmapRenderer::setRadiusMapUnitScale ( const QgsMapUnitScale & scale )

inline

Sets the map unit scale used for the heatmap's radius.

Parameters

scale map unit scale for heatmap's radius

See also: setRadius; setRadiusUnit; radiusMapUnitScale

Definition at line 129 of file qgsheatmaprenderer.h.

◆ setRadiusUnit()

void QgsHeatmapRenderer::setRadiusUnit ( const QgsSymbolV2::OutputUnit unit )

inline

Sets the units used for the heatmap's radius.

Parameters

unit	units for heatmap radius

See also: radiusUnit; setRadius; radiusMapUnitScale

Definition at line 114 of file qgsheatmaprenderer.h.

◆ setRenderQuality()

void QgsHeatmapRenderer::setRenderQuality ( const int quality )

inline

Sets the render quality used for drawing the heatmap.

Parameters

quality render quality. A value of 1 indicates maximum quality, and increasing the value will result in faster drawing but lower quality rendering.

See also: renderQuality

Definition at line 155 of file qgsheatmaprenderer.h.

◆ setWeightExpression()

void QgsHeatmapRenderer::setWeightExpression ( const QString & expression )

inline

Sets the expression used for weighting points when generating the heatmap.

Parameters

expression point weight expression. If set to empty, all points are equally weighted.

See also: weightExpression

Definition at line 167 of file qgsheatmaprenderer.h.

◆ startRender()

void QgsHeatmapRenderer::startRender	(	QgsRenderContext &	context,
		const QgsFields &	fields
	)

overridevirtual

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

Parameters

context	Additional information passed to the renderer about the job which will be rendered
fields	The 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 67 of file qgsheatmaprenderer.cpp.

◆ stopRender()

void QgsHeatmapRenderer::stopRender ( QgsRenderContext & context )

overridevirtual

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

Implements QgsFeatureRendererV2.

Definition at line 230 of file qgsheatmaprenderer.cpp.

◆ symbolForFeature()

QgsSymbolV2 * QgsHeatmapRenderer::symbolForFeature	(	QgsFeature &	feature,
		QgsRenderContext &	context
	)

overridevirtual

Note: symbolForFeature2 in python bindings

Reimplemented from QgsFeatureRendererV2.

Definition at line 380 of file qgsheatmaprenderer.cpp.

◆ symbols()

QgsSymbolV2List QgsHeatmapRenderer::symbols ( QgsRenderContext & context )

overridevirtual

Note: symbol2 in python bindings

Reimplemented from QgsFeatureRendererV2.

Definition at line 386 of file qgsheatmaprenderer.cpp.

◆ usedAttributes()

QList< QString > QgsHeatmapRenderer::usedAttributes ( )

overridevirtual

Returns a set of attributes required for this renderer.

TODO QGIS3: Change QList to QSet

Implements QgsFeatureRendererV2.

Definition at line 391 of file qgsheatmaprenderer.cpp.

◆ weightExpression()

QString QgsHeatmapRenderer::weightExpression ( ) const

inline

Returns the expression used for weighting points when generating the heatmap.

Returns: point weight expression. If empty, all points are equally weighted.

See also: setWeightExpression

Definition at line 161 of file qgsheatmaprenderer.h.

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

/tmp/buildd/qgis-2.18.21+99unstable/src/core/symbology-ng/qgsheatmaprenderer.h
/tmp/buildd/qgis-2.18.21+99unstable/src/core/symbology-ng/qgsheatmaprenderer.cpp

Public Member Functions

Static Public Member Functions

Additional Inherited Members

Detailed Description

Constructor & Destructor Documentation

◆ QgsHeatmapRenderer()

◆ ~QgsHeatmapRenderer()

Member Function Documentation

◆ clone()

◆ colorRamp()

◆ convertFromRenderer()

◆ create()

◆ dump()

◆ invertRamp()

◆ maximumValue()

◆ modifyRequestExtent()

◆ radius()

◆ radiusMapUnitScale()

◆ radiusUnit()

◆ renderFeature()

◆ renderQuality()

◆ save()

◆ setColorRamp()

◆ setInvertRamp()

◆ setMaximumValue()

◆ setRadius()

◆ setRadiusMapUnitScale()

◆ setRadiusUnit()

◆ setRenderQuality()

◆ setWeightExpression()

◆ startRender()

◆ stopRender()

◆ symbolForFeature()

◆ symbols()

◆ usedAttributes()

◆ weightExpression()