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.

Return type

QgsExpressionContextScope

Returns

An expression scope for details about this symbol

feature(self) → QgsFeature

Returns the current feature being rendered. This may be None.

Return type

QgsFeature

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 an empty QgsFields object).

New in version 2.4.

Return type

QgsFields

geometryPartCount(self) → int

Part count of current geometry

New in version 2.16.

Return type

int

geometryPartNum(self) → int

Part number of current geometry

New in version 2.16.

Return type

int

mapUnitScale(self) → QgsMapUnitScale

Deprecated since version Will: be removed in QGIS 4.0

Return type

QgsMapUnitScale

opacity(self) → float

Returns the opacity for the symbol.

Return type

float

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.

Return type

QgsWkbTypes.GeometryType

outputLineWidth(self, width: float) → float

Deprecated since version Use: the size conversion methods in QgsRenderContext instead.

Parameters

width (float) –

Return type

float

outputPixelSize(self, size: float) → float

Deprecated since version Use: the size conversion methods in QgsRenderContext instead.

Parameters

size (float) –

Return type

float

outputUnit(self) → QgsUnitTypes.RenderUnit

Returns the output unit for the context.

Deprecated since version No: longer used and will be removed in QGIS 4.0

Return type

QgsUnitTypes.RenderUnit

renderContext(self) → QgsRenderContext

Returns a reference to the context’s render context.

Return type

QgsRenderContext

renderHints(self) → QgsSymbol.RenderHints

Returns the rendering hint flags for the symbol.

See also

setRenderHints()

Return type

QgsSymbol.RenderHints

selected(self) → bool

Returns True if symbols should be rendered using the selected symbol coloring and style.

See also

setSelected()

Return type

bool

setExpressionContextScope(self, contextScope: QgsExpressionContextScope)

Set an expression scope for this symbol.

Will take ownership.

Parameters

contextScope (QgsExpressionContextScope) – An expression scope for details about this symbol

setFeature(self, f: QgsFeature)
Parameters

f (QgsFeature) –

setGeometryPartCount(self, count: int)

Sets the part count of current geometry

New in version 2.16.

Parameters

count (int) –

setGeometryPartNum(self, num: int)

Sets the part number of current geometry

New in version 2.16.

Parameters

num (int) –

setMapUnitScale(self, scale: QgsMapUnitScale)

Deprecated since version Will: be removed in QGIS 4.0

Parameters

scale (QgsMapUnitScale) –

setOpacity(self, opacity: float)

Sets the opacity for the symbol.

Parameters

opacity (float) – 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.

Parameters

type (QgsWkbTypes.GeometryType) –

setOriginalValueVariable(self, value: Any)

Sets the original value variable value for data defined symbology

Parameters

value (Any) – 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.

Deprecated since version No: longer used and will be removed in QGIS 4.0

Parameters

u (QgsUnitTypes.RenderUnit) –

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

Sets rendering hint flags for the symbol.

See also

renderHints()

Parameters

hints (Union[QgsSymbol.RenderHints) –

setSelected(self, selected: bool)

Sets whether symbols should be rendered using the selected symbol coloring and style.

See also

selected()

Parameters

selected (bool) –