Class: QgsAbstractVectorLayerLabeling

Abstract base class - its implementations define different approaches to the labeling of a vector layer.

Class Hierarchy

Subclasses

QgsRuleBasedLabeling	Rule based labeling for a vector layer.
QgsVectorLayerSimpleLabeling	Basic implementation of the labeling interface.

Methods

accept	Accepts the specified symbology visitor, causing it to visit all symbols associated with the labeling.
clone	Returns a new copy of the object
multiplyOpacity	Multiply opacity by opacityFactor.
requiresAdvancedEffects	Returns True if drawing labels requires advanced effects like composition modes, which could prevent it being used as an isolated cached image or exported to a vector format.
save	Returns labeling configuration as XML element
setSettings	Set pal settings for a specific provider (takes ownership).
settings	Gets associated label settings.
subProviders	Gets list of sub-providers within the layer's labeling.
toSld	Writes the SE 1.1 TextSymbolizer element based on the current layer labeling settings
type	Unique type string of the labeling configuration implementation
writeTextSymbolizer	Writes a TextSymbolizer element contents based on the provided labeling settings

Static Methods

create	Try to create instance of an implementation based on the XML data
defaultSettingsForLayer	Returns the default layer settings to use for the specified vector layer.

class qgis.core.QgsAbstractVectorLayerLabeling

Bases: object

accept(self, visitor: QgsStyleEntityVisitorInterface | None) → bool

Accepts the specified symbology visitor, causing it to visit all symbols associated with the labeling.

Returns True if the visitor should continue visiting other objects, or False if visiting should be canceled.

Added in version 3.10.

Parameters:

visitor (Optional[QgsStyleEntityVisitorInterface])

Return type:

bool

clone(self) → QgsAbstractVectorLayerLabeling | None

Returns a new copy of the object

Return type:

Optional[QgsAbstractVectorLayerLabeling]

static create(element: QDomElement, context: QgsReadWriteContext) → QgsAbstractVectorLayerLabeling | None

Try to create instance of an implementation based on the XML data

Parameters:

• element (QDomElement)

• context (QgsReadWriteContext)

Return type:

Optional[QgsAbstractVectorLayerLabeling]

static defaultSettingsForLayer(layer: QgsVectorLayer | None) → QgsPalLayerSettings

Returns the default layer settings to use for the specified vector layer.

Added in version 3.20.

Parameters:

layer (Optional[QgsVectorLayer])

Return type:

QgsPalLayerSettings

multiplyOpacity(self, opacityFactor: float)

Multiply opacity by opacityFactor.

This method multiplies the opacity of the labeling elements (text, shadow, buffer etc.) by opacity effectively changing the opacity of the whole labeling elements.

Added in version 3.32.

Parameters:

opacityFactor (float)

requiresAdvancedEffects(self) → bool

Returns True if drawing labels requires advanced effects like composition modes, which could prevent it being used as an isolated cached image or exported to a vector format.

Return type:

bool

save(self, doc: QDomDocument, context: QgsReadWriteContext) → QDomElement

Returns labeling configuration as XML element

Parameters:

• doc (QDomDocument)

• context (QgsReadWriteContext)

Return type:

QDomElement

setSettings(self, settings: QgsPalLayerSettings | None, providerId: str | None = '')

Set pal settings for a specific provider (takes ownership).

Parameters:

• settings (Optional[QgsPalLayerSettings]) – Pal layer settings

• providerId (Optional[str] = '') – The id of the provider

settings(self, providerId: str | None = '') → QgsPalLayerSettings

Gets associated label settings. In case of multiple sub-providers with different settings, they are identified by their ID (e.g. in case of rule-based labeling, provider ID == rule key)

Parameters:

providerId (Optional[str] = '')

Return type:

QgsPalLayerSettings

subProviders(self) → List[str]

Gets list of sub-providers within the layer’s labeling.

Return type:

List[str]

toSld(self, parent: QDomNode, props: Dict[str, Any])

Writes the SE 1.1 TextSymbolizer element based on the current layer labeling settings

Parameters:

• parent (QDomNode)

• props (Dict[str, Any])

type(self) → str

Unique type string of the labeling configuration implementation

Return type:

str

writeTextSymbolizer(self, parent: QDomNode, settings: QgsPalLayerSettings, props: Dict[str, Any])

Writes a TextSymbolizer element contents based on the provided labeling settings

Parameters:

• parent (QDomNode) – the node that will have the text symbolizer element added to it

• settings (QgsPalLayerSettings) – the settings getting translated to a TextSymbolizer

• props (Dict[str, Any]) – a open ended set of properties that can drive/inform the SLD encoding