Subgroup: Symbol

Class: QgsSymbolRenderContext

class qgis.core.QgsSymbolRenderContext(c: QgsRenderContext, u: QgsUnitTypes.RenderUnit, opacity: float = 1, selected: bool = False, renderHints: Union[QgsSymbol.RenderHints, QgsSymbol.RenderHint] = 0, f: QgsFeature = None, fields: QgsFields = QgsFields(), mapUnitScale: QgsMapUnitScale = QgsMapUnitScale())

Bases: sip.wrapper

Constructor for QgsSymbolRenderContext

Parameters:
expressionContextScope(self) → QgsExpressionContextScope

This scope is always available when a symbol of this type is being rendered.

Returns:An expression scope for details about this symbol
feature(self) → QgsFeature

Current feature being rendered - may be null

fields(self) → QgsFields

Fields of the layer. Currently only available in startRender() calls to allow symbols with data-defined properties prepare the expressions (other times fields() returns null)

New in version 2.4.

geometryPartCount(self) → int

Part count of current geometry

New in version 2.16.

geometryPartNum(self) → int

Part number of current geometry

New in version 2.16.

mapUnitScale(self) → QgsMapUnitScale
opacity(self) → float

Returns the opacity for the symbol.

Returns:opacity value between 0 (fully transparent) and 1 (fully opaque)

See also

setOpacity()

originalGeometryType(self) → QgsWkbTypes.GeometryType

Returns the geometry type for the original feature geometry being rendered. This can be useful if symbol layers alter their appearance based on geometry type - eg offsetting a simple line style will look different if the simple line is rendering a polygon feature (a closed buffer) vs a line feature (an unclosed offset line).

New in version 3.0.

outputLineWidth(self, width: float) → float
outputPixelSize(self, size: float) → float
outputUnit(self) → QgsUnitTypes.RenderUnit

Returns the output unit for the context

renderContext(self) → QgsRenderContext

Returns a reference to the context’s render context.

renderHints(self) → QgsSymbol.RenderHints

Returns the rendering hint flags for the symbol.

See also

setRenderHints()

selected(self) → bool
setExpressionContextScope(self, contextScope: QgsExpressionContextScope)

Set an expression scope for this symbol.

Will take ownership.

Parameters:contextScope – An expression scope for details about this symbol
setFeature(self, f: QgsFeature)
setGeometryPartCount(self, count: int)

Sets the part count of current geometry

New in version 2.16.

setGeometryPartNum(self, num: int)

Sets the part number of current geometry

New in version 2.16.

setMapUnitScale(self, scale: QgsMapUnitScale)
setOpacity(self, opacity: float)

Sets the opacity for the symbol.

Parameters:opacity – opacity value between 0 (fully transparent) and 1 (fully opaque)

See also

opacity()

setOriginalGeometryType(self, type: QgsWkbTypes.GeometryType)

Sets the geometry type for the original feature geometry being rendered.

New in version 3.0.

setOriginalValueVariable(self, value: Any)

Sets the original value variable value for data defined symbology

Parameters:value – value for original value variable. This usually represents the symbol property value before any data defined overrides have been applied.

New in version 2.12.

setOutputUnit(self, u: QgsUnitTypes.RenderUnit)

Sets the output unit for the context

setRenderHints(self, hints: Union[QgsSymbol.RenderHints, QgsSymbol.RenderHint])

Sets rendering hint flags for the symbol.

See also

renderHints()

setSelected(self, selected: bool)