Class: QgsInterpolatedLineSymbolLayer

A symbol layer that represents vector layer line features as interpolated lines.

The interpolation is done between two values defined at the extremities.

Added in version 3.20.

Class Hierarchy

Base classes

QgsLineSymbolLayer	Abstract base class for line symbol layers.
QgsSymbolLayer	Abstract base class for symbol layers.

Methods

endValueExpressionForColor	Returns the expression related to the end extremity value for width for color
endValueExpressionForWidth	Returns the expression related to the end extremity value for width.
interpolatedColor	Returns the interpolated color used to render the colors of lines, see :py:class:`QgsInterpolatedLineColor`.
interpolatedWidth	Returns the interpolated width used to render the width of lines, see :py:class:`QgsInterpolatedLineWidth`.
setExpressionsStringForColor	Sets the expressions (as string) that define the extremety values af the line feature for color.
setExpressionsStringForWidth	Sets the expressions (as string) that define the extremety values af the line feature for width.
setInterpolatedColor	Sets the interpolated color used to render the colors of lines, see QgsInterpolatedLineColor.
setInterpolatedWidth	Sets the interpolated width used to render the width of lines, see QgsInterpolatedLineWidth.
setWidthUnit	Sets the width unit.
startValueExpressionForColor	Returns the epression related to the start extremity value for width for color
startValueExpressionForWidth	Returns the epression related to the start extremity value for width.
widthUnit	Returns the width unit.

Static Methods

create

Creates the symbol layer

class qgis.core.QgsInterpolatedLineSymbolLayer

Bases: QgsLineSymbolLayer

static create(properties: Dict[str, Any]) → QgsSymbolLayer | None

Creates the symbol layer

Parameters:

properties (Dict[str, Any])

Return type:

Optional[QgsSymbolLayer]

endValueExpressionForColor(self) → str

Returns the expression related to the end extremity value for width for color

Deprecated since version 3.40: Use dataDefinedProperty( QgsSymbolLayer.PropertyLineEndColorValue ) instead.

Return type:

str

endValueExpressionForWidth(self) → str

Returns the expression related to the end extremity value for width.

Deprecated since version 3.40: Use dataDefinedProperty( QgsSymbolLayer.PropertyLineEndWidthValue ) instead.

Return type:

str

interpolatedColor(self) → QgsInterpolatedLineColor

Returns the interpolated color used to render the colors of lines, see :py:class:`QgsInterpolatedLineColor`.

See also

setInterpolatedColor()

Return type:

QgsInterpolatedLineColor

interpolatedWidth(self) → QgsInterpolatedLineWidth

Returns the interpolated width used to render the width of lines, see :py:class:`QgsInterpolatedLineWidth`.

See also

setInterpolatedWidth()

Return type:

QgsInterpolatedLineWidth

setExpressionsStringForColor(self, start: str | None, end: str | None)

Sets the expressions (as string) that define the extremety values af the line feature for color.

Deprecated since version 3.40: Use setDataDefinedProperty( QgsSymbolLayer.PropertyLineStartColorValue ) and setDataDefinedProperty( QgsSymbolLayer.PropertyLineEndColorValue ) instead.

Parameters:

• start (Optional[str])

• end (Optional[str])

setExpressionsStringForWidth(self, start: str | None, end: str | None)

Sets the expressions (as string) that define the extremety values af the line feature for width.

Deprecated since version 3.40: Use setDataDefinedProperty( QgsSymbolLayer.PropertyLineStartWidthValue ) and setDataDefinedProperty( QgsSymbolLayer.PropertyLineEndWidthValue ) instead.

Parameters:

• start (Optional[str])

• end (Optional[str])

setInterpolatedColor(self, interpolatedLineColor: QgsInterpolatedLineColor)

Sets the interpolated color used to render the colors of lines, see QgsInterpolatedLineColor.

See also

interpolatedColor()

Parameters:

interpolatedLineColor (QgsInterpolatedLineColor)

setInterpolatedWidth(self, interpolatedLineWidth: QgsInterpolatedLineWidth)

Sets the interpolated width used to render the width of lines, see QgsInterpolatedLineWidth.

See also

interpolatedWidth()

Parameters:

interpolatedLineWidth (QgsInterpolatedLineWidth)

setWidthUnit(self, strokeWidthUnit: Qgis.RenderUnit)

Sets the width unit.

See also

widthUnit()

Parameters:

strokeWidthUnit (Qgis.RenderUnit)

startValueExpressionForColor(self) → str

Returns the epression related to the start extremity value for width for color

Deprecated since version 3.40: Use dataDefinedProperty( QgsSymbolLayer.PropertyLineStartColorValue ) instead.

Return type:

str

startValueExpressionForWidth(self) → str

Returns the epression related to the start extremity value for width.

Deprecated since version 3.40: Use dataDefinedProperty( QgsSymbolLayer.PropertyLineStartWidthValue ) instead.

Return type:

str

widthUnit(self) → Qgis.RenderUnit

Returns the width unit.

See also

setWidthUnit()

Return type:

Qgis.RenderUnit