QGIS API Documentation 3.39.0-Master (bca3cdb6021)
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QgsMergedFeatureRenderer is a polygon or line-only feature renderer used to renderer a set of features merged (or dissolved) into a single geometry. More...
#include <qgsmergedfeaturerenderer.h>
Public Member Functions | |
QgsMergedFeatureRenderer (const QgsMergedFeatureRenderer &)=delete | |
Direct copies are forbidden. Use clone() instead. | |
QgsMergedFeatureRenderer (QgsFeatureRenderer *embeddedRenderer) | |
Constructor for QgsMergedFeatureRenderer. | |
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=true) override |
Sets whether the legend symbology item with the specified ley should be checked. | |
QgsMergedFeatureRenderer * | clone () const override |
Create a deep copy of this renderer. | |
QString | dump () const override |
Returns debug information about this renderer. | |
const QgsFeatureRenderer * | embeddedRenderer () const override |
Returns the current embedded renderer (subrenderer) for this feature renderer. | |
bool | filterNeedsGeometry () const override |
Returns true if this renderer requires the geometry to apply the filter. | |
Qgis::FeatureRendererFlags | flags () const override |
Returns flags associated with the renderer. | |
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. | |
QgsMergedFeatureRenderer & | operator= (const QgsMergedFeatureRenderer &)=delete |
Direct copies are forbidden. Use clone() instead. | |
QgsSymbol * | originalSymbolForFeature (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 |
Renders a given feature. | |
QDomElement | save (QDomDocument &doc, const QgsReadWriteContext &context) override |
Stores renderer properties to an XML element. | |
void | setEmbeddedRenderer (QgsFeatureRenderer *subRenderer) override |
Sets an embedded renderer (subrenderer) for this feature renderer. | |
void | setLegendSymbolItem (const QString &key, QgsSymbol *symbol) override |
Sets the symbol to be used for a legend symbol item. | |
void | startRender (QgsRenderContext &context, const QgsFields &fields) override |
Must be called when a new render cycle is started. | |
void | stopRender (QgsRenderContext &context) override |
The actual rendering will take place here. | |
QgsSymbol * | symbolForFeature (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. | |
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. | |
QgsPropertyCollection & | dataDefinedProperties () |
Returns a reference to the renderer's property collection, used for data defined overrides. | |
const QgsPropertyCollection & | dataDefinedProperties () const |
Returns a reference to the renderer's property collection, used for data defined overrides. | |
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. | |
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. | |
QgsPaintEffect * | paintEffect () 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. | |
virtual void | toSld (QDomDocument &doc, QDomElement &element, const QVariantMap &props=QVariantMap()) const |
used from subclasses to create SLD Rule elements following SLD v1.1 specs | |
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 QgsMergedFeatureRenderer * | convertFromRenderer (const QgsFeatureRenderer *renderer) |
Creates a QgsMergedFeatureRenderer by a conversion from an existing renderer. | |
static QgsFeatureRenderer * | create (QDomElement &element, const QgsReadWriteContext &context) |
Creates a renderer out of an XML, for loading. | |
Static Public Member Functions inherited from QgsFeatureRenderer | |
static QgsFeatureRenderer * | defaultRenderer (Qgis::GeometryType geomType) |
Returns a new renderer - used by default in vector layers. | |
static QgsFeatureRenderer * | load (QDomElement &symbologyElem, const QgsReadWriteContext &context) |
create a renderer from XML element | |
static QgsFeatureRenderer * | 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. | |
static const QgsPropertiesDefinition & | propertyDefinitions () |
Returns the symbol property definitions. | |
Protected Types | |
enum | GeometryOperation { Merge , InvertOnly , MergeAndInvert } |
Operations to apply to collected geometries prior to rendering. More... | |
Protected Member Functions | |
QgsMergedFeatureRenderer (const QString &type, QgsFeatureRenderer *embeddedRenderer) | |
Constructor for QgsMergedFeatureRenderer. | |
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. | |
Protected Attributes | |
GeometryOperation | mOperation = Merge |
Operation to apply to collected geometries. | |
std::unique_ptr< QgsFeatureRenderer > | mSubRenderer |
Embedded renderer. | |
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 |
QgsPaintEffect * | mPaintEffect = nullptr |
double | mReferenceScale = -1.0 |
QString | mType |
bool | mUsingSymbolLevels = false |
Additional Inherited Members | |
Public Types inherited from QgsFeatureRenderer | |
typedef QFlags< Capability > | Capabilities |
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... | |
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) |
QgsMergedFeatureRenderer is a polygon or line-only feature renderer used to renderer a set of features merged (or dissolved) into a single geometry.
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. E.g. if the embedded renderer is a categorized renderer, then all the matching features for each categorized class will be dissolved together. Features from different classes will NOT be dissolved together.
Definition at line 40 of file qgsmergedfeaturerenderer.h.
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Operations to apply to collected geometries prior to rendering.
Enumerator | |
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Merge | Merge features (union/dissolve) |
InvertOnly | Invert features only (polygons only) |
MergeAndInvert | Merge and invert features (polygons only) |
Definition at line 120 of file qgsmergedfeaturerenderer.h.
QgsMergedFeatureRenderer::QgsMergedFeatureRenderer | ( | QgsFeatureRenderer * | embeddedRenderer | ) |
Constructor for QgsMergedFeatureRenderer.
embeddedRenderer | optional embeddedRenderer. Ownership will be transferred. |
Definition at line 34 of file qgsmergedfeaturerenderer.cpp.
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delete |
Direct copies are forbidden. Use clone() instead.
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protected |
Constructor for QgsMergedFeatureRenderer.
type | renderer ID string |
embeddedRenderer | optional embeddedRenderer. Ownership will be transferred. |
Definition at line 40 of file qgsmergedfeaturerenderer.cpp.
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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.
Reimplemented from QgsFeatureRenderer.
Definition at line 91 of file qgsmergedfeaturerenderer.cpp.
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overridevirtual |
Returns details about internals of this renderer.
E.g. if you only want to deal with visible features:
Reimplemented from QgsFeatureRenderer.
Definition at line 542 of file qgsmergedfeaturerenderer.cpp.
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overridevirtual |
Sets whether the legend symbology item with the specified ley should be checked.
Reimplemented from QgsFeatureRenderer.
Definition at line 83 of file qgsmergedfeaturerenderer.cpp.
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overridevirtual |
Create a deep copy of this renderer.
Should be implemented by all subclasses and generate a proper subclass.
Implements QgsFeatureRenderer.
Definition at line 440 of file qgsmergedfeaturerenderer.cpp.
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Creates a QgsMergedFeatureRenderer by a conversion from an existing renderer.
nullptr
. Definition at line 583 of file qgsmergedfeaturerenderer.cpp.
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Creates a renderer out of an XML, for loading.
Definition at line 455 of file qgsmergedfeaturerenderer.cpp.
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overridevirtual |
Returns debug information about this renderer.
Reimplemented from QgsFeatureRenderer.
Definition at line 431 of file qgsmergedfeaturerenderer.cpp.
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overridevirtual |
Returns the current embedded renderer (subrenderer) for this feature renderer.
The base class implementation does not use subrenderers and will always return nullptr
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Reimplemented from QgsFeatureRenderer.
Definition at line 54 of file qgsmergedfeaturerenderer.cpp.
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overridevirtual |
Returns true
if this renderer requires the geometry to apply the filter.
Reimplemented from QgsFeatureRenderer.
Definition at line 560 of file qgsmergedfeaturerenderer.cpp.
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overridevirtual |
Returns flags associated with the renderer.
Reimplemented from QgsFeatureRenderer.
Definition at line 169 of file qgsmergedfeaturerenderer.cpp.
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overridevirtual |
Returns legend keys matching a specified feature.
Reimplemented from QgsFeatureRenderer.
Definition at line 518 of file qgsmergedfeaturerenderer.cpp.
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overridevirtual |
Attempts to convert the specified legend rule key to a QGIS expression matching the features displayed using that key.
key | legend key |
layer | associated vector layer |
ok | will be set to true if legend key was successfully converted to a filter expression |
Reimplemented from QgsFeatureRenderer.
Definition at line 525 of file qgsmergedfeaturerenderer.cpp.
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overridevirtual |
Returns true
if the legend symbology item with the specified key is checked.
Reimplemented from QgsFeatureRenderer.
Definition at line 75 of file qgsmergedfeaturerenderer.cpp.
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overridevirtual |
Returns a list of symbology items for the legend.
Reimplemented from QgsFeatureRenderer.
Definition at line 565 of file qgsmergedfeaturerenderer.cpp.
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overridevirtual |
Returns true
if symbology items in legend are checkable.
Reimplemented from QgsFeatureRenderer.
Definition at line 67 of file qgsmergedfeaturerenderer.cpp.
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delete |
Direct copies are forbidden. Use clone() instead.
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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.
Reimplemented from QgsFeatureRenderer.
Definition at line 495 of file qgsmergedfeaturerenderer.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 511 of file qgsmergedfeaturerenderer.cpp.
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overridevirtual |
Renders a given feature.
This will here collect features. The actual rendering will be postponed to stopRender()
feature | the feature to render |
context | the rendering context |
layer | the symbol layer to render, if that makes sense |
selected | whether this feature has been selected (this will add decorations) |
drawVertexMarker | whether this feature has vertex markers (in edit mode usually) |
true
if the rendering was OK Reimplemented from QgsFeatureRenderer.
Definition at line 179 of file qgsmergedfeaturerenderer.cpp.
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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 468 of file qgsmergedfeaturerenderer.cpp.
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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.
subRenderer | the embedded renderer. Ownership will be transferred. |
Reimplemented from QgsFeatureRenderer.
Definition at line 49 of file qgsmergedfeaturerenderer.cpp.
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overridevirtual |
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 59 of file qgsmergedfeaturerenderer.cpp.
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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.
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 99 of file qgsmergedfeaturerenderer.cpp.
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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 290 of file qgsmergedfeaturerenderer.cpp.
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overridevirtual |
To be overridden.
Must be called between startRender() and stopRender() calls.
feature | feature |
context | render context |
Implements QgsFeatureRenderer.
Definition at line 486 of file qgsmergedfeaturerenderer.cpp.
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overridevirtual |
Returns list of symbols used by the renderer.
context | render context |
Reimplemented from QgsFeatureRenderer.
Definition at line 533 of file qgsmergedfeaturerenderer.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 502 of file qgsmergedfeaturerenderer.cpp.
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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.
Implements QgsFeatureRenderer.
Definition at line 551 of file qgsmergedfeaturerenderer.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 574 of file qgsmergedfeaturerenderer.cpp.
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protected |
Operation to apply to collected geometries.
Definition at line 128 of file qgsmergedfeaturerenderer.h.
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protected |
Embedded renderer.
Definition at line 131 of file qgsmergedfeaturerenderer.h.