Class: QgsInvertedPolygonRenderer

QgsInvertedPolygonRenderer is a polygon-only feature renderer used to display features inverted, where the exterior is turned to an interior and where the exterior theoretically spans the entire plane, allowing to mask the surroundings of some features.

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.

Features are collected to form one “inverted” polygon during renderFeature() and rendered on stopRender().

Class Hierarchy

Base classes

QgsMergedFeatureRenderer	QgsMergedFeatureRenderer is a polygon or line-only feature renderer used to renderer a set of features merged (or dissolved) into a single geometry.
QgsFeatureRenderer	Abstract base class for all 2D vector feature renderers.

Methods

preprocessingEnabled
setPreprocessingEnabled

Static Methods

convertFromRenderer

Creates a QgsInvertedPolygonRenderer by a conversion from an existing renderer.

class qgis.core.QgsInvertedPolygonRenderer

Bases: QgsMergedFeatureRenderer

__init__(embeddedRenderer: QgsFeatureRenderer | None = None)

Constructor

Parameters:

embeddedRenderer (Optional[QgsFeatureRenderer] = None) – optional embeddedRenderer. If None, a default one will be assigned. Ownership will be transferred.

static convertFromRenderer(renderer: QgsFeatureRenderer | None) → QgsInvertedPolygonRenderer | None

Creates a QgsInvertedPolygonRenderer by a conversion from an existing renderer.

Return type:

Optional[QgsInvertedPolygonRenderer]

Returns:

a new renderer if the conversion was possible, otherwise None.

Parameters:

renderer (Optional[QgsFeatureRenderer])

preprocessingEnabled(self) → bool

Return type:

bool

Returns:

True if the geometries are to be preprocessed (merged with

an union) before rendering.

setPreprocessingEnabled(self, enabled: bool)

Parameters:

enabled (bool) – enables or disables the preprocessing. When enabled,

geometries will be merged with an union before being rendered. It allows fixing some rendering artifacts (when rendering overlapping polygons for instance). This will involve some CPU-demanding computations and is thus disabled by default.