Class: QgsLegendRenderer

Handles automatic layout and rendering of legends.

The content is given by QgsLayerTreeModel instance. Various layout properties can be configured within QgsLegendRenderer.

All spacing and sizes are in millimeters.

Methods

drawLegend	Draws the legend with given painter.
exportLegendToJson	Renders the legend in a json object.
legendSize	Returns the preferred legend size set by the client.
minimumSize	Runs the layout algorithm and returns the minimum size required for the legend.
proxyModel	Returns the filter proxy model used for filtering the legend model content during rendering.
setLegendSize	Sets the preferred resulting legend size.

Static Methods

nodeLegendStyle	Returns the style for the given node, within the specified model.
setNodeLegendStyle	Sets the style of a node.

class qgis.core.QgsLegendRenderer

Bases: object

__init__(legendModel: QgsLayerTreeModel | None, settings: QgsLegendSettings)

Constructor for QgsLegendRenderer. The ownership of the legend model is not changed, and the model must exist for the lifetime of this renderer.

Parameters:

• legendModel (Optional[QgsLayerTreeModel])

• settings (QgsLegendSettings)

drawLegend(self, painter: QPainter | None)

Draws the legend with given painter. The legend will occupy the area reported in legendSize(). The painter should be scaled beforehand so that units correspond to millimeters.

Deprecated since version 3.40: Use the variant which accepts a QgsRenderContext instead.

Parameters:

painter (Optional[QPainter])

drawLegend(self, context: QgsRenderContext)

Draws the legend using a given render context. The legend will occupy the area reported in legendSize().

Added in version 3.6.

Parameters:

context (QgsRenderContext)

exportLegendToJson(self, context: QgsRenderContext) → Dict[str, QJsonValue]

Renders the legend in a json object.

Added in version 3.8.

Parameters:

context (QgsRenderContext)

Return type:

Dict[str, QJsonValue]

legendSize(self) → QSizeF

Returns the preferred legend size set by the client.

If the returned size is null, the legend will be drawn with the minimum possible size to fit its content.

See also

minimumSize()

See also

setLegendSize()

Return type:

QSizeF

minimumSize(self, renderContext: QgsRenderContext | None = None) → QSizeF

Runs the layout algorithm and returns the minimum size required for the legend.

See also

setLegendSize()

See also

legendSize()

Parameters:

renderContext (Optional[QgsRenderContext] = None)

Return type:

QSizeF

static nodeLegendStyle(node: QgsLayerTreeNode | None, model: QgsLayerTreeModel | None) → Qgis.LegendComponent

Returns the style for the given node, within the specified model.

See also

setNodeLegendStyle()

Parameters:

• node (Optional[QgsLayerTreeNode])

• model (Optional[QgsLayerTreeModel])

Return type:

Qgis.LegendComponent

proxyModel(self) → QgsLayerTreeFilterProxyModel | None

Returns the filter proxy model used for filtering the legend model content during rendering.

Filters can be set on the proxy model to filter rendered legend content.

Added in version 3.40.

Return type:

Optional[QgsLayerTreeFilterProxyModel]

setLegendSize(self, s: QSizeF)

Sets the preferred resulting legend size.

If the size is null, the legend will be drawn with the minimum possible size to fit its content.

See also

legendSize()

See also

minimumSize()

Parameters:

s (QSizeF)

static setNodeLegendStyle(node: QgsLayerTreeNode | None, style: Qgis.LegendComponent)

Sets the style of a node.

See also

nodeLegendStyle()

Parameters:

• node (Optional[QgsLayerTreeNode])

• style (Qgis.LegendComponent)