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QgsInvertedPolygonRenderer Class Reference

QgsInvertedPolygonRenderer is a polygon-only feature renderer used to display features inverted, where the exterior is turned to an interior and where the exterior theoretically spans the entire plane, allowing to mask the surroundings of some features. More...

#include <qgsinvertedpolygonrenderer.h>

Inheritance diagram for QgsInvertedPolygonRenderer:
Inheritance graph
[legend]

Classes

struct  CombinedFeature
 Structure where the reversed geometry is built during renderFeature.
struct  FeatureDecoration
 Class used to represent features that must be rendered with decorations (selection, vertex markers)

Public Member Functions

 QgsInvertedPolygonRenderer (const QgsFeatureRendererV2 *embeddedRenderer=0)
 Constructor.
virtual ~QgsInvertedPolygonRenderer ()
virtual QgsFeatureRendererV2clone () const
 Used to clone this feature renderer.
virtual void startRender (QgsRenderContext &context, const QgsFields &fields)
virtual bool renderFeature (QgsFeature &feature, QgsRenderContext &context, int layer=-1, bool selected=false, bool drawVertexMarker=false)
 Renders a given feature.
virtual void stopRender (QgsRenderContext &context)
 The actual rendering will take place here.
virtual QString dump () const
virtual QList< QString > usedAttributes ()
 Proxy that will call this method on the embedded renderer.
virtual int capabilities ()
 Proxy that will call this method on the embedded renderer.
virtual QgsSymbolV2List symbols ()
 Proxy that will call this method on the embedded renderer.
virtual QgsSymbolV2symbolForFeature (QgsFeature &feature)
 Proxy that will call this method on the embedded renderer.
virtual QgsSymbolV2List symbolsForFeature (QgsFeature &feat)
 Proxy that will call this method on the embedded renderer.
virtual QgsLegendSymbologyList legendSymbologyItems (QSize iconSize)
 Proxy that will call this method on the embedded renderer.
virtual QgsLegendSymbolList legendSymbolItems (double scaleDenominator=-1, QString rule="")
 Proxy that will call this method on the embedded renderer.
virtual bool willRenderFeature (QgsFeature &feat)
 Proxy that will call this method on the embedded renderer.
virtual QDomElement save (QDomDocument &doc)
 Creates an XML representation of the renderer.
void setEmbeddedRenderer (const QgsFeatureRendererV2 *subRenderer)
 sets the embedded renderer
const QgsFeatureRendererV2embeddedRenderer () const
bool preprocessingEnabled () const
void setPreprocessingEnabled (bool enabled)
- Public Member Functions inherited from QgsFeatureRendererV2
QString type () const
virtual Q_DECL_DEPRECATED void startRender (QgsRenderContext &context, const QgsVectorLayer *vlayer)
virtual ~QgsFeatureRendererV2 ()
bool usingSymbolLevels () const
void setUsingSymbolLevels (bool usingSymbolLevels)
virtual QDomElement writeSld (QDomDocument &doc, const QgsVectorLayer &layer) const
 create the SLD UserStyle element following the SLD v1.1 specs
virtual void toSld (QDomDocument &doc, QDomElement &element) const
 used from subclasses to create SLD Rule elements following SLD v1.1 specs
virtual bool legendSymbolItemsCheckable () const
 items of symbology items in legend should be checkable
virtual bool legendSymbolItemChecked (QString key)
 items of symbology items in legend is checked
virtual void checkLegendSymbolItem (QString key, bool state=true)
 item in symbology was checked
virtual QgsLegendSymbolListV2 legendSymbolItemsV2 () const
 Return a list of symbology items for the legend.
virtual QString legendClassificationAttribute () const
 If supported by the renderer, return classification attribute for the use in legend.
void setVertexMarkerAppearance (int type, int size)
 set type and size of editing vertex markers for subsequent rendering
virtual QString rotationField () const
 return rotation field name (or empty string if not set or not supported by renderer)
virtual void setRotationField (QString fieldName)
 sets rotation field of renderer (if supported by the renderer)

Static Public Member Functions

static QgsFeatureRendererV2create (QDomElement &element)
 Creates a renderer out of an XML, for loading.
static QgsInvertedPolygonRendererconvertFromRenderer (const QgsFeatureRendererV2 *renderer)
 creates a QgsInvertedPolygonRenderer by a conversion from an existing renderer.
- Static Public Member Functions inherited from QgsFeatureRendererV2
static QgsFeatureRendererV2defaultRenderer (QGis::GeometryType geomType)
 return a new renderer - used by default in vector layers
static QgsFeatureRendererV2load (QDomElement &symbologyElem)
 create a renderer from XML element
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

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 (QString type)
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
void renderVertexMarkerPolyline (QPolygonF &pts, QgsRenderContext &context)
 render editing vertex marker for a polyline
void renderVertexMarkerPolygon (QPolygonF &pts, QList< QPolygonF > *rings, QgsRenderContext &context)
 render editing vertex marker for a polygon
void setScaleMethodToSymbol (QgsSymbolV2 *symbol, int scaleMethod)
- Static Protected Member Functions inherited from QgsFeatureRendererV2
static const unsigned char * _getPoint (QPointF &pt, QgsRenderContext &context, const unsigned char *wkb)
static const unsigned char * _getLineString (QPolygonF &pts, QgsRenderContext &context, const unsigned char *wkb)
static const unsigned char * _getPolygon (QPolygonF &pts, QList< QPolygonF > &holes, QgsRenderContext &context, const unsigned char *wkb)
- Protected Attributes inherited from QgsFeatureRendererV2
QString mType
bool mUsingSymbolLevels
int mCurrentVertexMarkerType
 The current type of editing marker.
int mCurrentVertexMarkerSize
 The current size of editing marker.

Detailed Description

QgsInvertedPolygonRenderer is a polygon-only feature renderer used to display features inverted, where the exterior is turned to an interior and where the exterior theoretically spans the entire plane, allowing to mask the surroundings of some features.

It is designed on top of another feature renderer, which is called "embedded" Most of the methods are then only proxies to the embedded renderer.

Features are collected to form one "inverted" polygon during renderFeature() and rendered on stopRender().

Note
added in 2.4

Constructor & Destructor Documentation

QgsInvertedPolygonRenderer::QgsInvertedPolygonRenderer ( const QgsFeatureRendererV2 embeddedRenderer = 0)

Constructor.

Parameters
embeddedRendereroptional embeddedRenderer. If null, a default one will be assigned
QgsInvertedPolygonRenderer::~QgsInvertedPolygonRenderer ( )
virtual

Member Function Documentation

int QgsInvertedPolygonRenderer::capabilities ( )
virtual

Proxy that will call this method on the embedded renderer.

Reimplemented from QgsFeatureRendererV2.

QgsFeatureRendererV2 * QgsInvertedPolygonRenderer::clone ( ) const
virtual

Used to clone this feature renderer.

Implements QgsFeatureRendererV2.

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

creates a QgsInvertedPolygonRenderer by a conversion from an existing renderer.

Note
added in 2.5
Returns
a new renderer if the conversion was possible, otherwise 0.
QgsFeatureRendererV2 * QgsInvertedPolygonRenderer::create ( QDomElement &  element)
static

Creates a renderer out of an XML, for loading.

QString QgsInvertedPolygonRenderer::dump ( ) const
virtual
Returns
a textual representation of the renderer

Reimplemented from QgsFeatureRendererV2.

const QgsFeatureRendererV2 * QgsInvertedPolygonRenderer::embeddedRenderer ( ) const
Returns
the current embedded renderer
QgsLegendSymbolList QgsInvertedPolygonRenderer::legendSymbolItems ( double  scaleDenominator = -1,
QString  rule = "" 
)
virtual

Proxy that will call this method on the embedded renderer.

Note
not available in python bindings

Reimplemented from QgsFeatureRendererV2.

QgsLegendSymbologyList QgsInvertedPolygonRenderer::legendSymbologyItems ( QSize  iconSize)
virtual

Proxy that will call this method on the embedded renderer.

Reimplemented from QgsFeatureRendererV2.

bool QgsInvertedPolygonRenderer::preprocessingEnabled ( ) const
inline
Returns
true if the geometries are to be preprocessed (merged with an union) before rendering.
bool QgsInvertedPolygonRenderer::renderFeature ( QgsFeature feature,
QgsRenderContext context,
int  layer = -1,
bool  selected = false,
bool  drawVertexMarker = false 
)
virtual

Renders a given feature.

This will here collect features. The actual rendering will be postponed to stopRender()

Parameters
featurethe feature to render
contextthe rendering context
layerthe symbol layer to render, if that makes sense
selectedwhether this feature has been selected (this will add decorations)
drawVertexMarkerwhether this feature has vertex markers (in edit mode usually)
Returns
true if the rendering was ok

Reimplemented from QgsFeatureRendererV2.

QDomElement QgsInvertedPolygonRenderer::save ( QDomDocument &  doc)
virtual

Creates an XML representation of the renderer.

Used for saving purpose

Parameters
docthe XML document where to create the XML subtree
Returns
the created XML subtree

Reimplemented from QgsFeatureRendererV2.

void QgsInvertedPolygonRenderer::setEmbeddedRenderer ( const QgsFeatureRendererV2 subRenderer)

sets the embedded renderer

Parameters
subRendererthe embedded renderer (will be cloned)
void QgsInvertedPolygonRenderer::setPreprocessingEnabled ( bool  enabled)
inline
Parameters
enabledenables or disables the preprocessing. When enabled, geometries will be merged with an union before being rendered. It allows to fix some rendering artefacts (when rendering overlapping polygons for instance). This will involve some CPU-demanding computations and is thus disabled by default.
void QgsInvertedPolygonRenderer::startRender ( QgsRenderContext context,
const QgsFields fields 
)
virtual

Implements QgsFeatureRendererV2.

void QgsInvertedPolygonRenderer::stopRender ( QgsRenderContext context)
virtual

The actual rendering will take place here.

Features collected during renderFeature() are rendered using the embedded feature renderer

Implements QgsFeatureRendererV2.

QgsSymbolV2 * QgsInvertedPolygonRenderer::symbolForFeature ( QgsFeature feature)
virtual

Proxy that will call this method on the embedded renderer.

Implements QgsFeatureRendererV2.

QgsSymbolV2List QgsInvertedPolygonRenderer::symbols ( )
virtual

Proxy that will call this method on the embedded renderer.

Implements QgsFeatureRendererV2.

QgsSymbolV2List QgsInvertedPolygonRenderer::symbolsForFeature ( QgsFeature feat)
virtual

Proxy that will call this method on the embedded renderer.

Reimplemented from QgsFeatureRendererV2.

QList< QString > QgsInvertedPolygonRenderer::usedAttributes ( )
virtual

Proxy that will call this method on the embedded renderer.

Implements QgsFeatureRendererV2.

bool QgsInvertedPolygonRenderer::willRenderFeature ( QgsFeature feat)
virtual

Proxy that will call this method on the embedded renderer.

Reimplemented from QgsFeatureRendererV2.


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