Subgroup: Feature
Class: QgsFeatureRenderer¶
-
class
qgis.core.
QgsFeatureRenderer
(type: str)¶ Bases:
sip.wrapper
Methods
capabilities
Returns details about internals of this renderer. checkLegendSymbolItem
item in symbology was checked clone
Create a deep copy of this renderer. convertSymbolRotation
convertSymbolSizeScale
copyRendererData
Clones generic renderer data to another renderer. defaultRenderer
return a new renderer - used by default in vector layers dump
Returns debug information about this renderer embeddedRenderer
Returns the current embedded renderer (subrenderer) for this feature renderer. filter
If a renderer does not require all the features this method may be overridden and return an expression used as where clause. filterNeedsGeometry
Returns true if this renderer requires the geometry to apply the filter. forceRasterRender
Returns whether the renderer must render as a raster. legendClassificationAttribute
If supported by the renderer, return classification attribute for the use in legend legendKeysForFeature
Return legend keys matching a specified feature. legendSymbolItemChecked
items of symbology items in legend is checked legendSymbolItems
Returns a list of symbology items for the legend legendSymbolItemsCheckable
items of symbology items in legend should be checkable load
create a renderer from XML element loadSld
Create a new renderer according to the information contained in modifyRequestExtent
Allows for a renderer to modify the extent of a feature request prior to rendering orderBy
Get the order in which features shall be processed by this renderer. orderByEnabled
Returns whether custom ordering will be applied before features are processed by this renderer. originalSymbolForFeature
Return symbol for feature. originalSymbolsForFeature
Equivalent of originalSymbolsForFeature() call paintEffect
Returns the current paint effect for the renderer. renderFeature
Render a feature using this renderer in the given context. renderFeatureWithSymbol
renderVertexMarker
render editing vertex marker at specified point renderVertexMarkerPolygon
render editing vertex marker for a polygon renderVertexMarkerPolyline
render editing vertex marker for a polyline save
store renderer info to XML element setEmbeddedRenderer
Sets an embedded renderer (subrenderer) for this feature renderer. setForceRasterRender
Sets whether the renderer should be rendered to a raster destination. setLegendSymbolItem
Sets the symbol to be used for a legend symbol item. setOrderBy
Define the order in which features shall be processed by this renderer. setOrderByEnabled
Sets whether custom ordering should be applied before features are processed by this renderer. setPaintEffect
Sets the current paint effect for the renderer. setUsingSymbolLevels
setVertexMarkerAppearance
set type and size of editing vertex markers for subsequent rendering startRender
Must be called when a new render cycle is started. stopRender
Must be called when a render cycle has finished, to allow the renderer to clean up. symbolForFeature
To be overridden symbols
Returns list of symbols used by the renderer. symbolsForFeature
Returns list of symbols used for rendering the feature. toSld
used from subclasses to create SLD Rule elements following SLD v1.1 specs type
usedAttributes
Return a list of attributes required by this renderer. usingSymbolLevels
willRenderFeature
Returns whether the renderer will render a feature or not. writeSld
create the SLD UserStyle element following the SLD v1.1 specs with the given name Attributes
Filter
MoreSymbolsPerFeature
ScaleDependent
SymbolLevels
-
class
Capabilities
¶ Bases:
sip.wrapper
QgsFeatureRenderer.Capabilities(Union[QgsFeatureRenderer.Capabilities, QgsFeatureRenderer.Capability]) QgsFeatureRenderer.Capabilities(QgsFeatureRenderer.Capabilities)
-
class
Capability
¶ Bases:
int
-
Filter
= 8¶
-
MoreSymbolsPerFeature
= 4¶
-
ScaleDependent
= 16¶
-
SymbolLevels
= 1¶
-
capabilities
(self) → QgsFeatureRenderer.Capabilities¶ 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()
-
checkLegendSymbolItem
(self, key: str, state: bool = True)¶ item in symbology was checked
New in version 2.5.
-
clone
(self) → QgsFeatureRenderer¶ Create a deep copy of this renderer. Should be implemented by all subclasses and generate a proper subclass.
Returns: A copy of this renderer
-
convertSymbolRotation
(symbol: QgsSymbol, field: str)¶ Note
this function is used to convert old rotations expressions to symbol level DataDefined angle
-
convertSymbolSizeScale
(symbol: QgsSymbol, method: QgsSymbol.ScaleMethod, field: str)¶ Note
this function is used to convert old sizeScale expressions to symbol level DataDefined size
-
copyRendererData
(self, destRenderer: QgsFeatureRenderer)¶ Clones generic renderer data to another renderer. Currently clones * Order By * Paint Effect
Parameters: destRenderer – destination renderer for copied effect
-
defaultRenderer
(geomType: QgsWkbTypes.GeometryType) → QgsFeatureRenderer¶ return a new renderer - used by default in vector layers
-
dump
(self) → str¶ Returns debug information about this renderer
-
embeddedRenderer
(self) → QgsFeatureRenderer¶ Returns the current embedded renderer (subrenderer) for this feature renderer. The base class implementation does not use subrenderers and will always return null.
See also
New in version 2.16.
-
filter
(self, fields: QgsFields = QgsFields()) → str¶ 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.
Returns: An expression used as where clause
-
filterNeedsGeometry
(self) → bool¶ Returns true if this renderer requires the geometry to apply the filter.
-
forceRasterRender
(self) → bool¶ Returns whether the renderer must render as a raster.
New in version 2.12.
See also
-
legendClassificationAttribute
(self) → str¶ If supported by the renderer, return classification attribute for the use in legend
New in version 2.6.
-
legendKeysForFeature
(self, feature: QgsFeature, context: QgsRenderContext) → Set[str]¶ Return legend keys matching a specified feature.
New in version 2.14.
-
legendSymbolItemChecked
(self, key: str) → bool¶ items of symbology items in legend is checked
New in version 2.5.
-
legendSymbolItems
(self) → object¶ Returns a list of symbology items for the legend
New in version 2.6.
-
legendSymbolItemsCheckable
(self) → bool¶ items of symbology items in legend should be checkable
New in version 2.5.
-
load
(symbologyElem: QDomElement, context: QgsReadWriteContext) → QgsFeatureRenderer¶ create a renderer from XML element
-
loadSld
(node: QDomNode, geomType: QgsWkbTypes.GeometryType, errorMessage: str) → QgsFeatureRenderer¶ Create a new renderer according to the information contained in the UserStyle element of a SLD style document
Parameters: node – the node in the SLD document whose the UserStyle element is a child :param geomType: the geometry type of the features, used to convert Symbolizer elements :param errorMessage: it will contain the error message if something went wrong
Returns: the renderer
-
modifyRequestExtent
(self, extent: QgsRectangle, context: QgsRenderContext)¶ 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 :param context: render context
New in version 2.7.
-
orderBy
(self) → QgsFeatureRequest.OrderBy¶ Get the order in which features shall be processed by this renderer.
New in version 2.14.
Note
this property has no effect if orderByEnabled() is false
See also
-
orderByEnabled
(self) → bool¶ Returns whether custom ordering will be applied before features are processed by this renderer.
New in version 2.14.
See also
See also
-
originalSymbolForFeature
(self, feature: QgsFeature, context: QgsRenderContext) → QgsSymbol¶ 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.
New in version 2.12.
-
originalSymbolsForFeature
(self, feat: QgsFeature, context: QgsRenderContext) → object¶ Equivalent of originalSymbolsForFeature() call extended to support renderers that may use more symbols per feature - similar to symbolsForFeature()
New in version 2.12.
-
paintEffect
(self) → QgsPaintEffect¶ Returns the current paint effect for the renderer.
Returns: paint effect New in version 2.9.
See also
-
renderFeature
(self, feature: QgsFeature, context: QgsRenderContext, layer: int = -1, selected: bool = False, drawVertexMarker: bool = False) → bool¶ 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).
See also
See also
-
renderFeatureWithSymbol
(self, feature: QgsFeature, symbol: QgsSymbol, context: QgsRenderContext, layer: int, selected: bool, drawVertexMarker: bool)¶
-
renderVertexMarker
(self, pt: Union[QPointF, QPoint], context: QgsRenderContext)¶ render editing vertex marker at specified point
-
renderVertexMarkerPolygon
(self, pts: QPolygonF, rings: Iterable[QPolygonF], context: QgsRenderContext)¶ render editing vertex marker for a polygon
-
renderVertexMarkerPolyline
(self, pts: QPolygonF, context: QgsRenderContext)¶ render editing vertex marker for a polyline
-
save
(self, doc: QDomDocument, context: QgsReadWriteContext) → QDomElement¶ store renderer info to XML element
-
setEmbeddedRenderer
(self, subRenderer: QgsFeatureRenderer)¶ 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: subRenderer – the embedded renderer. Ownership will be transferred. See also
New in version 2.16.
-
setForceRasterRender
(self, forceRaster: bool)¶ Sets whether the renderer should be rendered to a raster destination.
Parameters: forceRaster – set to true if renderer must be drawn on a raster surface. This may be desirable for highly detailed layers where rendering as a vector would result in a large, complex vector output.
See also
New in version 2.12.
-
setLegendSymbolItem
(self, key: str, symbol: QgsSymbol)¶ Sets the symbol to be used for a legend symbol item.
Parameters: - key – rule key for legend symbol
- symbol – new symbol for legend item. Ownership is transferred to renderer.
New in version 2.14.
-
setOrderBy
(self, orderBy: QgsFeatureRequest.OrderBy)¶ Define the order in which features shall be processed by this renderer.
Note
this property has no effect if orderByEnabled() is false
New in version 2.14.
See also
-
setOrderByEnabled
(self, enabled: bool)¶ Sets whether custom ordering should be applied before features are processed by this renderer.
Parameters: enabled – set to true to enable custom feature ordering New in version 2.14.
See also
See also
-
setPaintEffect
(self, effect: QgsPaintEffect)¶ Sets the current paint effect for the renderer.
Parameters: effect – paint effect. Ownership is transferred to the renderer. New in version 2.9.
See also
-
setUsingSymbolLevels
(self, usingSymbolLevels: bool)¶
-
setVertexMarkerAppearance
(self, type: int, size: int)¶ set type and size of editing vertex markers for subsequent rendering
-
startRender
(self, context: QgsRenderContext, fields: QgsFields)¶ 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: - context – Additional information passed to the renderer about the job which will be rendered
- fields – The fields available for rendering
See also
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.
-
stopRender
(self, context: QgsRenderContext)¶ 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().
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.
See also
-
symbolForFeature
(self, feature: QgsFeature, context: QgsRenderContext) → QgsSymbol¶ To be overridden
Must be called between startRender() and stopRender() calls.
Parameters: - feature – feature
- context – render context
Returns: returns pointer to symbol or 0 if symbol was not found
New in version 2.12.
-
symbols
(self, context: QgsRenderContext) → object¶ Returns list of symbols used by the renderer.
Parameters: context – render context New in version 2.12.
-
symbolsForFeature
(self, feat: QgsFeature, context: QgsRenderContext) → object¶ Returns list of symbols used for rendering the feature. For renderers that do not support MoreSymbolsPerFeature it is more efficient to use symbolForFeature()
New in version 2.12.
-
toSld
(self, doc: QDomDocument, element: QDomElement, props: Dict[str, str] = {})¶ used from subclasses to create SLD Rule elements following SLD v1.1 specs
-
type
(self) → str¶
-
usedAttributes
(self, context: QgsRenderContext) → Set[str]¶ 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.
Returns: A set of attributes
-
usingSymbolLevels
(self) → bool¶
-
willRenderFeature
(self, feat: QgsFeature, context: QgsRenderContext) → bool¶ Returns whether the renderer will render a feature or not. Must be called between startRender() and stopRender() calls. Default implementation uses symbolForFeature().
New in version 2.12.
-
writeSld
(self, doc: QDomDocument, styleName: str, props: Dict[str, str] = {}) → QDomElement¶ create the SLD UserStyle element following the SLD v1.1 specs with the given name
New in version 2.8.
-
class