Class: QgsColorRampTransformer¶
- class qgis.core.QgsColorRampTransformer¶
Bases:
QgsPropertyTransformer
QgsPropertyTransformer
subclass for transforming a numeric value into a color from a color ramp.New in version 3.0.
QgsColorRampTransformer(minValue: float = 0, maxValue: float = 1, ramp:
QgsColorRamp
= None, nullColor: Union[QColor, Qt.GlobalColor, QGradient] = QColor(0,0,0,0)) Constructor for QgsColorRampTransformer.- Parameters:
minValue – minimum expected value
maxValue – maximum expected value
ramp – source color ramp. Ownership is transferred to the transformer.
nullColor – color to return for null values
QgsColorRampTransformer(other:
QgsColorRampTransformer
) Copy constructorMethods
- rtype:
QgsColorRampTransformer
Calculates the color corresponding to a specific value.
Returns the color ramp used for calculating property colors.
- param definition:
Returns the color corresponding to a null value.
Returns the color ramp's name.
Sets the color ramp to use for calculating property colors.
Sets the color corresponding to a null value.
Sets the color ramp's
name
.- param baseExpression:
- rtype:
Any
- param context:
Applies base class numeric transformations.
- rtype:
QgsPropertyTransformer.Type
- clone(self) QgsColorRampTransformer ¶
- Return type:
- color(self, value: float) QColor ¶
Calculates the color corresponding to a specific value.
- Parameters:
value (float) – value to calculate color for
- Return type:
QColor
- Returns:
calculated color using transformer’s parameters and type
- colorRamp(self) QgsColorRamp ¶
Returns the color ramp used for calculating property colors.
- Return type:
- Returns:
color ramp
See also
- loadVariant(self, definition: Any) bool ¶
- Parameters:
definition (Any) –
- Return type:
bool
- nullColor(self) QColor ¶
Returns the color corresponding to a null value.
See also
- Return type:
QColor
- rampName(self) str ¶
Returns the color ramp’s name.
See also
- Return type:
str
- setColorRamp(self, ramp: QgsColorRamp)¶
Sets the color ramp to use for calculating property colors.
- Parameters:
ramp (QgsColorRamp) – color ramp, ownership of ramp is transferred to the transformer.
See also
- setNullColor(self, color: QColor | Qt.GlobalColor | QGradient)¶
Sets the color corresponding to a null value.
- Parameters:
color (Union[QColor) – null color
See also
- setRampName(self, name: str)¶
Sets the color ramp’s
name
. The ramp name must be set to match a color ramp available in the style database for conversion to expression to work correctly.See also
- Parameters:
name (str) –
- toExpression(self, baseExpression: str) str ¶
- Parameters:
baseExpression (str) –
- Return type:
str
- toVariant(self) Any ¶
- Return type:
Any
- transform(self, context: QgsExpressionContext, value: Any) Any ¶
- Parameters:
context (QgsExpressionContext) –
value (Any) –
- Return type:
Any
- transformNumeric(self, input: float) float ¶
Applies base class numeric transformations. Derived classes should call this to transform an
input
numeric value before they apply any transform to the result. This applies any curve transforms which may exist on the transformer.
- transformerType(self) QgsPropertyTransformer.Type ¶
- Return type: