Class: QgsMapLayerLegend¶

An abstract interface for implementations of legends for one map layer.

Note

This is an abstract class, with methods which must be implemented by a subclass.

The following methods must be implemented: createLayerTreeModelLegendNodes()

Class Hierarchy¶

Base classes¶

Subclasses¶

`QgsDefaultMeshLayerLegend`	Default legend implementation for mesh layers.
`QgsDefaultPointCloudLayerLegend`	Default legend implementation for point cloud layers.
`QgsDefaultRasterLayerLegend`	Default legend implementation for raster layers.
`QgsDefaultVectorLayerLegend`	Default legend implementation for vector layers.

Abstract Methods

createLayerTreeModelLegendNodes

Returns list of legend nodes to be used for a particular layer tree layer node.

Virtual Methods

In PyQGIS, only methods marked as virtual can be safely overridden in a Python subclass of QgsMapLayerLegend. See the FAQ for more details.

`readXml`	Reads configuration from a DOM element previously written by `writeXml()`
`writeXml`	Writes configuration to a DOM element, to be used later with `readXml()`

Static Methods

`defaultMeshLegend`	Create new legend implementation for mesh layer
`defaultPointCloudLegend`	Create new legend implementation for a point cloud layer.
`defaultRasterLegend`	Create new legend implementation for raster layer
`defaultVectorLegend`	Create new legend implementation for vector layer

Signals

itemsChanged

Emitted when existing items/nodes got invalid and should be replaced by new ones

class qgis.core.QgsMapLayerLegend[source]¶

Bases: QObject

__init__(parent: QObject | None = None)

Constructor for QgsMapLayerLegend

Parameters:: parent (Optional[QObject] = None)

abstract createLayerTreeModelLegendNodes(self, nodeLayer: QgsLayerTreeLayer | None) → List[QgsLayerTreeModelLegendNode]¶

Returns list of legend nodes to be used for a particular layer tree layer node. Ownership is transferred to the caller.

Parameters:: nodeLayer (Optional[QgsLayerTreeLayer])
Return type:: List[QgsLayerTreeModelLegendNode]

static defaultMeshLegend(ml: QgsMeshLayer | None) → QgsMapLayerLegend | None[source]¶

Create new legend implementation for mesh layer

Parameters:: ml (Optional[QgsMeshLayer])
Return type:: Optional[QgsMapLayerLegend]

static defaultPointCloudLegend(layer: QgsPointCloudLayer | None) → QgsMapLayerLegend | None[source]¶

Create new legend implementation for a point cloud layer.

Added in version 3.18.

Parameters:: layer (Optional[QgsPointCloudLayer])
Return type:: Optional[QgsMapLayerLegend]

static defaultRasterLegend(rl: QgsRasterLayer | None) → QgsMapLayerLegend | None[source]¶

Create new legend implementation for raster layer

Parameters:: rl (Optional[QgsRasterLayer])
Return type:: Optional[QgsMapLayerLegend]

static defaultVectorLegend(vl: QgsVectorLayer | None) → QgsMapLayerLegend | None[source]¶

Create new legend implementation for vector layer

Parameters:: vl (Optional[QgsVectorLayer])
Return type:: Optional[QgsMapLayerLegend]

signal itemsChanged[source]¶: Emitted when existing items/nodes got invalid and should be replaced by new ones

virtual readXml(self, elem: QDomElement, context: QgsReadWriteContext)[source]¶

Reads configuration from a DOM element previously written by writeXml()

Added in version 3.2.

Parameters:

elem (QDomElement)
context (QgsReadWriteContext)

virtual writeXml(self, doc: QDomDocument, context: QgsReadWriteContext) → QDomElement[source]¶

Writes configuration to a DOM element, to be used later with readXml()

Added in version 3.2.

Parameters:

doc (QDomDocument)
context (QgsReadWriteContext)

Return type:

QDomElement