QGIS API Documentation  3.13.0-Master (7f54853aae)
Classes | Public Member Functions | Static Public Member Functions | List of all members
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]

Public Member Functions

 QgsInvertedPolygonRenderer (QgsFeatureRenderer *embeddedRenderer=nullptr)
 Constructor. More...
 
 QgsInvertedPolygonRenderer (const QgsInvertedPolygonRenderer &)=delete
 Direct copies are forbidden. Use clone() instead. 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=true) override
 item in symbology was checked More...
 
QgsInvertedPolygonRendererclone () const override
 Create a deep copy of this renderer. More...
 
QString dump () const override
 Returns debug information about this renderer. More...
 
const QgsFeatureRendererembeddedRenderer () const override
 Returns the current embedded renderer (subrenderer) for this feature renderer. More...
 
bool filterNeedsGeometry () const override
 Returns true if this renderer requires the geometry to apply the filter. 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...
 
QgsInvertedPolygonRendereroperator= (const QgsInvertedPolygonRenderer &)=delete
 Direct copies are forbidden. Use clone() instead. 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 preprocessingEnabled () const
 
bool renderFeature (const QgsFeature &feature, QgsRenderContext &context, int layer=-1, bool selected=false, bool drawVertexMarker=false) override SIP_THROW(QgsCsException)
 Renders a given feature. More...
 
QDomElement save (QDomDocument &doc, const QgsReadWriteContext &context) override
 store renderer info to XML element More...
 
void setEmbeddedRenderer (QgsFeatureRenderer *subRenderer) override
 Sets an embedded renderer (subrenderer) for this feature renderer. More...
 
void setLegendSymbolItem (const QString &key, QgsSymbol *symbol) override
 Sets the symbol to be used for a legend symbol item. More...
 
void setPreprocessingEnabled (bool enabled)
 
void startRender (QgsRenderContext &context, const QgsFields &fields) override
 Must be called when a new render cycle is started. More...
 
void stopRender (QgsRenderContext &context) override
 The actual rendering will take place here. 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...
 
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 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...
 
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...
 
virtual void toSld (QDomDocument &doc, QDomElement &element, const QgsStringMap &props=QgsStringMap()) const
 used from subclasses to create SLD Rule elements following SLD v1.1 specs 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 QgsInvertedPolygonRendererconvertFromRenderer (const QgsFeatureRenderer *renderer)
 Creates a QgsInvertedPolygonRenderer by a conversion from an existing renderer. More...
 
static QgsFeatureRenderercreate (QDomElement &element, const QgsReadWriteContext &context)
 Creates a renderer out of an XML, for loading. 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 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 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 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

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().

Since
QGIS 2.4

Definition at line 41 of file qgsinvertedpolygonrenderer.h.

Constructor & Destructor Documentation

◆ QgsInvertedPolygonRenderer() [1/2]

QgsInvertedPolygonRenderer::QgsInvertedPolygonRenderer ( QgsFeatureRenderer embeddedRenderer = nullptr)

Constructor.

Parameters
embeddedRendereroptional embeddedRenderer. If nullptr, a default one will be assigned. Ownership will be transferred.

Definition at line 33 of file qgsinvertedpolygonrenderer.cpp.

◆ QgsInvertedPolygonRenderer() [2/2]

QgsInvertedPolygonRenderer::QgsInvertedPolygonRenderer ( const QgsInvertedPolygonRenderer )
delete

Direct copies are forbidden. Use clone() instead.

Member Function Documentation

◆ accept()

bool QgsInvertedPolygonRenderer::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 95 of file qgsinvertedpolygonrenderer.cpp.

◆ capabilities()

QgsFeatureRenderer::Capabilities QgsInvertedPolygonRenderer::capabilities ( )
overridevirtual

Returns details about internals of this renderer.

E.g. if you only want to deal with visible features:

if not renderer.capabilities().testFlag(QgsFeatureRenderer.Filter) or renderer.willRenderFeature(feature, context):
deal_with_my_feature()
else:
skip_the_curren_feature()

Reimplemented from QgsFeatureRenderer.

Definition at line 484 of file qgsinvertedpolygonrenderer.cpp.

◆ checkLegendSymbolItem()

void QgsInvertedPolygonRenderer::checkLegendSymbolItem ( const QString &  key,
bool  state = true 
)
overridevirtual

item in symbology was checked

Since
QGIS 2.5

Reimplemented from QgsFeatureRenderer.

Definition at line 87 of file qgsinvertedpolygonrenderer.cpp.

◆ clone()

QgsInvertedPolygonRenderer * QgsInvertedPolygonRenderer::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 377 of file qgsinvertedpolygonrenderer.cpp.

◆ convertFromRenderer()

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

Creates a QgsInvertedPolygonRenderer by a conversion from an existing renderer.

Returns
a new renderer if the conversion was possible, otherwise 0.
Since
QGIS 2.5

Definition at line 525 of file qgsinvertedpolygonrenderer.cpp.

◆ create()

QgsFeatureRenderer * QgsInvertedPolygonRenderer::create ( QDomElement &  element,
const QgsReadWriteContext context 
)
static

Creates a renderer out of an XML, for loading.

Definition at line 393 of file qgsinvertedpolygonrenderer.cpp.

◆ dump()

QString QgsInvertedPolygonRenderer::dump ( ) const
overridevirtual

Returns debug information about this renderer.

Reimplemented from QgsFeatureRenderer.

Definition at line 368 of file qgsinvertedpolygonrenderer.cpp.

◆ embeddedRenderer()

const QgsFeatureRenderer * QgsInvertedPolygonRenderer::embeddedRenderer ( ) const
overridevirtual

Returns the current embedded renderer (subrenderer) for this feature renderer.

The base class implementation does not use subrenderers and will always return nullptr.

See also
setEmbeddedRenderer()
Since
QGIS 2.16

Reimplemented from QgsFeatureRenderer.

Definition at line 58 of file qgsinvertedpolygonrenderer.cpp.

◆ filterNeedsGeometry()

bool QgsInvertedPolygonRenderer::filterNeedsGeometry ( ) const
overridevirtual

Returns true if this renderer requires the geometry to apply the filter.

Reimplemented from QgsFeatureRenderer.

Definition at line 502 of file qgsinvertedpolygonrenderer.cpp.

◆ legendKeysForFeature()

QSet< QString > QgsInvertedPolygonRenderer::legendKeysForFeature ( const QgsFeature feature,
QgsRenderContext context 
) const
overridevirtual

Returns legend keys matching a specified feature.

Since
QGIS 2.14

Reimplemented from QgsFeatureRenderer.

Definition at line 468 of file qgsinvertedpolygonrenderer.cpp.

◆ legendSymbolItemChecked()

bool QgsInvertedPolygonRenderer::legendSymbolItemChecked ( const QString &  key)
overridevirtual

items of symbology items in legend is checked

Since
QGIS 2.5

Reimplemented from QgsFeatureRenderer.

Definition at line 79 of file qgsinvertedpolygonrenderer.cpp.

◆ legendSymbolItems()

QgsLegendSymbolList QgsInvertedPolygonRenderer::legendSymbolItems ( ) const
overridevirtual

Returns a list of symbology items for the legend.

Since
QGIS 2.6

Reimplemented from QgsFeatureRenderer.

Definition at line 507 of file qgsinvertedpolygonrenderer.cpp.

◆ legendSymbolItemsCheckable()

bool QgsInvertedPolygonRenderer::legendSymbolItemsCheckable ( ) const
overridevirtual

items of symbology items in legend should be checkable

Since
QGIS 2.5

Reimplemented from QgsFeatureRenderer.

Definition at line 71 of file qgsinvertedpolygonrenderer.cpp.

◆ operator=()

QgsInvertedPolygonRenderer& QgsInvertedPolygonRenderer::operator= ( const QgsInvertedPolygonRenderer )
delete

Direct copies are forbidden. Use clone() instead.

◆ originalSymbolForFeature()

QgsSymbol * QgsInvertedPolygonRenderer::originalSymbolForFeature ( const QgsFeature feature,
QgsRenderContext context 
) const
overridevirtual

Returns 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.

Since
QGIS 2.12

Reimplemented from QgsFeatureRenderer.

Definition at line 445 of file qgsinvertedpolygonrenderer.cpp.

◆ originalSymbolsForFeature()

QgsSymbolList QgsInvertedPolygonRenderer::originalSymbolsForFeature ( const QgsFeature feature,
QgsRenderContext context 
) const
overridevirtual

Equivalent of originalSymbolsForFeature() call extended to support renderers that may use more symbols per feature - similar to symbolsForFeature()

Since
QGIS 2.12

Reimplemented from QgsFeatureRenderer.

Definition at line 461 of file qgsinvertedpolygonrenderer.cpp.

◆ preprocessingEnabled()

bool QgsInvertedPolygonRenderer::preprocessingEnabled ( ) const
inline
Returns
true if the geometries are to be preprocessed (merged with an union) before rendering.

Definition at line 107 of file qgsinvertedpolygonrenderer.h.

◆ renderFeature()

bool QgsInvertedPolygonRenderer::renderFeature ( const QgsFeature feature,
QgsRenderContext context,
int  layer = -1,
bool  selected = false,
bool  drawVertexMarker = false 
)
overridevirtual

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 QgsFeatureRenderer.

Definition at line 162 of file qgsinvertedpolygonrenderer.cpp.

◆ save()

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

store renderer info to XML element

Reimplemented from QgsFeatureRenderer.

Definition at line 407 of file qgsinvertedpolygonrenderer.cpp.

◆ setEmbeddedRenderer()

void QgsInvertedPolygonRenderer::setEmbeddedRenderer ( QgsFeatureRenderer subRenderer)
overridevirtual

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.

Parameters
subRendererthe embedded renderer. Ownership will be transferred.
See also
embeddedRenderer()
Since
QGIS 2.16

Reimplemented from QgsFeatureRenderer.

Definition at line 46 of file qgsinvertedpolygonrenderer.cpp.

◆ setLegendSymbolItem()

void QgsInvertedPolygonRenderer::setLegendSymbolItem ( const QString &  key,
QgsSymbol symbol 
)
overridevirtual

Sets the symbol to be used for a legend symbol item.

Parameters
keyrule key for legend symbol
symbolnew symbol for legend item. Ownership is transferred to renderer.
Since
QGIS 2.14

Reimplemented from QgsFeatureRenderer.

Definition at line 63 of file qgsinvertedpolygonrenderer.cpp.

◆ setPreprocessingEnabled()

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 fixing some rendering artifacts (when rendering overlapping polygons for instance). This will involve some CPU-demanding computations and is thus disabled by default.

Definition at line 115 of file qgsinvertedpolygonrenderer.h.

◆ startRender()

void QgsInvertedPolygonRenderer::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 103 of file qgsinvertedpolygonrenderer.cpp.

◆ stopRender()

void QgsInvertedPolygonRenderer::stopRender ( QgsRenderContext context)
overridevirtual

The actual rendering will take place here.

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

Reimplemented from QgsFeatureRenderer.

Definition at line 255 of file qgsinvertedpolygonrenderer.cpp.

◆ symbolForFeature()

QgsSymbol * QgsInvertedPolygonRenderer::symbolForFeature ( const QgsFeature feature,
QgsRenderContext context 
) const
overridevirtual

To be overridden.

Must be called between startRender() and stopRender() calls.

Parameters
featurefeature
contextrender context
Returns
returns pointer to symbol or 0 if symbol was not found
Since
QGIS 2.12

Implements QgsFeatureRenderer.

Definition at line 436 of file qgsinvertedpolygonrenderer.cpp.

◆ symbols()

QgsSymbolList QgsInvertedPolygonRenderer::symbols ( QgsRenderContext context) const
overridevirtual

Returns list of symbols used by the renderer.

Parameters
contextrender context
Since
QGIS 2.12

Reimplemented from QgsFeatureRenderer.

Definition at line 475 of file qgsinvertedpolygonrenderer.cpp.

◆ symbolsForFeature()

QgsSymbolList QgsInvertedPolygonRenderer::symbolsForFeature ( const QgsFeature feature,
QgsRenderContext context 
) const
overridevirtual

Returns list of symbols used for rendering the feature.

For renderers that do not support MoreSymbolsPerFeature it is more efficient to use symbolForFeature()

Since
QGIS 2.12

Reimplemented from QgsFeatureRenderer.

Definition at line 452 of file qgsinvertedpolygonrenderer.cpp.

◆ usedAttributes()

QSet< QString > QgsInvertedPolygonRenderer::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 493 of file qgsinvertedpolygonrenderer.cpp.

◆ willRenderFeature()

bool QgsInvertedPolygonRenderer::willRenderFeature ( const QgsFeature feature,
QgsRenderContext context 
) const
overridevirtual

Returns whether the renderer will render a feature or not.

Must be called between startRender() and stopRender() calls. Default implementation uses symbolForFeature().

Since
QGIS 2.12

Reimplemented from QgsFeatureRenderer.

Definition at line 516 of file qgsinvertedpolygonrenderer.cpp.


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