Class: QgsRasterShader¶

Interface for all raster shaders.

class qgis.core.QgsRasterShader[source]¶

Bases: object

maximumValue(self) → float[source]¶

Returns the maximum value for the raster shader.

See also

setMaximumValue()

See also

minimumValue()

Return type:: float

minimumValue(self) → float[source]¶

Returns the minimum value for the raster shader.

See also

setMinimumValue()

See also

maximumValue()

Return type:: float

rasterShaderFunction(self) → QgsRasterShaderFunction | None[source]¶

Return type:: Optional[QgsRasterShaderFunction]

readXml(self, elem: QDomElement, context: QgsReadWriteContext = QgsReadWriteContext())[source]¶

Reads shader state from an XML element.

Parameters:

elem (QDomElement)
context (QgsReadWriteContext = QgsReadWriteContext())

setMaximumValue(self, value: float)[source]¶

Sets the maximum value for the raster shader.

See also

setMinimumValue()

See also

maximumValue()

Parameters:: value (float)

setMinimumValue(self, value: float)[source]¶

Sets the minimum value for the raster shader.

See also

setMaximumValue()

See also

minimumValue()

Parameters:: value (float)

setRasterShaderFunction(self, function: QgsRasterShaderFunction | None)[source]¶

A public method that allows the user to set their own shader function.

Note

Raster shader takes ownership of the shader function instance

Parameters:: function (Optional[QgsRasterShaderFunction])

shade(self, value: float)[source]¶

Generates a new RGBA value based on one input value.

Parameters:

value (float) -> (bool) – The original value to base a new RGBA value on

Returns:

True if the return values are valid otherwise False
returnRedValue: The red component of the new RGBA value
returnGreenValue: The green component of the new RGBA value
returnBlueValue: The blue component of the new RGBA value
returnAlpha: The alpha component of the new RGBA value

shade(self, redValue: float, greenValue: float, blueValue: float, alphaValue: float) -> (bool, Optional[int], Optional[int], Optional[int], Optional[int]) Generates a new RGBA value based on an original RGBA value.

Parameters:

redValue – The red component of the original value to base a new RGBA value on
greenValue – The green component of the original value to base a new RGBA value on
blueValue – The blue component of the original value to base a new RGBA value on
alphaValue – The alpha component of the original value to base a new RGBA value on

Returns:

True if the return values are valid otherwise False
returnRedValue: The red component of the new RGBA value
returnGreenValue: The green component of the new RGBA value
returnBlueValue: The blue component of the new RGBA value
returnAlpha: The alpha component of the new RGBA value

writeXml(self, doc: QDomDocument, parent: QDomElement, context: QgsReadWriteContext = QgsReadWriteContext())[source]¶

Writes shader state to an XML element.

Parameters:

doc (QDomDocument)
parent (QDomElement)
context (QgsReadWriteContext = QgsReadWriteContext())