QgsColorRampTransformer Class Reference

QgsPropertyTransformer subclass for transforming a numeric value into a color from a color ramp. More...

#include <qgspropertytransformer.h>

Inheritance diagram for QgsColorRampTransformer:

Public Member Functions
	QgsColorRampTransformer (const QgsColorRampTransformer &other)
	Copy constructor. More...
	QgsColorRampTransformer (double minValue=0.0, double maxValue=1.0, QgsColorRamp *ramp=nullptr, const QColor &nullColor=QColor(0, 0, 0, 0))
	Constructor for QgsColorRampTransformer. More...
QgsColorRampTransformer *	clone () const override
	Returns a clone of the transformer. More...
QColor	color (double value) const
	Calculates the color corresponding to a specific value. More...
QgsColorRamp *	colorRamp () const
	Returns the color ramp used for calculating property colors. More...
bool	loadVariant (const QVariant &definition) override
	Loads this transformer from a QVariantMap, wrapped in a QVariant. More...
QColor	nullColor () const
	Returns the color corresponding to a null value. More...
QgsColorRampTransformer &	operator= (const QgsColorRampTransformer &other)
QString	rampName () const
	Returns the color ramp's name. More...
void	setColorRamp (QgsColorRamp *ramp)
	Sets the color ramp to use for calculating property colors. More...
void	setNullColor (const QColor &color)
	Sets the color corresponding to a null value. More...
void	setRampName (const QString &name)
	Sets the color ramp's name. More...
QString	toExpression (const QString &baseExpression) const override
	Converts the transformer to a QGIS expression string. More...
QVariant	toVariant () const override
	Saves this transformer to a QVariantMap, wrapped in a QVariant. More...
QVariant	transform (const QgsExpressionContext &context, const QVariant &value) const override
	Calculates the transform of a value. More...
Type	transformerType () const override
	Returns the transformer type. More...
Public Member Functions inherited from QgsPropertyTransformer
	QgsPropertyTransformer (const QgsPropertyTransformer &other)
	Copy constructor. More...
	QgsPropertyTransformer (double minValue=0.0, double maxValue=1.0)
	Constructor for QgsPropertyTransformer. More...
virtual	~QgsPropertyTransformer ()
virtual QgsPropertyTransformer *	clone () const =0
	Returns a clone of the transformer. More...
QgsCurveTransform *	curveTransform () const
	Returns the curve transform applied to input values before they are transformed by the individual transform subclasses. More...
virtual bool	loadVariant (const QVariant &transformer)
	Loads this transformer from a QVariantMap, wrapped in a QVariant. More...
double	maxValue () const
	Returns the maximum value expected by the transformer. More...
double	minValue () const
	Returns the minimum value expected by the transformer. More...
QgsPropertyTransformer &	operator= (const QgsPropertyTransformer &other)
void	setCurveTransform (QgsCurveTransform *transform)
	Sets a curve transform to apply to input values before they are transformed by the individual transform subclasses. More...
void	setMaxValue (double max)
	Sets the maximum value expected by the transformer. More...
void	setMinValue (double min)
	Sets the minimum value expected by the transformer. More...
virtual QString	toExpression (const QString &baseExpression) const =0
	Converts the transformer to a QGIS expression string. More...
virtual QVariant	toVariant () const
	Saves this transformer to a QVariantMap, wrapped in a QVariant. More...
virtual QVariant	transform (const QgsExpressionContext &context, const QVariant &value) const =0
	Calculates the transform of a value. More...
virtual Type	transformerType () const =0
	Returns the transformer type. More...

Additional Inherited Members
Public Types inherited from QgsPropertyTransformer
enum	Type { GenericNumericTransformer , SizeScaleTransformer , ColorRampTransformer }
	Transformer types. More...
Static Public Member Functions inherited from QgsPropertyTransformer
static QgsPropertyTransformer *	create (Type type)
	Factory method for creating a new property transformer of the specified type. More...
static QgsPropertyTransformer *	fromExpression (const QString &expression, QString &baseExpression, QString &fieldName)
	Attempts to parse an expression into a corresponding property transformer. More...
Protected Member Functions inherited from QgsPropertyTransformer
double	transformNumeric (double input) const
	Applies base class numeric transformations. More...
Protected Attributes inherited from QgsPropertyTransformer
std::unique_ptr< QgsCurveTransform >	mCurveTransform
	Optional curve transform. More...
double	mMaxValue
	Maximum value expected by the transformer. More...
double	mMinValue
	Minimum value expected by the transformer. More...

Detailed Description

QgsPropertyTransformer subclass for transforming a numeric value into a color from a color ramp.

Since

QGIS 3.0

Definition at line 608 of file qgspropertytransformer.h.

Constructor & Destructor Documentation

QgsColorRampTransformer() [1/2]

QgsColorRampTransformer::QgsColorRampTransformer	(	double	minValue = 0.0,
		double	maxValue = 1.0,
		QgsColorRamp *	ramp = nullptr,
		const QColor &	nullColor = 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

Definition at line 525 of file qgspropertytransformer.cpp.

QgsColorRampTransformer() [2/2]

QgsColorRampTransformer::QgsColorRampTransformer

(

const QgsColorRampTransformer &

other

)

Copy constructor.

Definition at line 535 of file qgspropertytransformer.cpp.

Member Function Documentation

clone()

QgsColorRampTransformer * QgsColorRampTransformer::clone ( ) const

overridevirtual

Returns a clone of the transformer.

Implements QgsPropertyTransformer.

Definition at line 555 of file qgspropertytransformer.cpp.

color()

QColor QgsColorRampTransformer::color

(

double

value

)

const

Calculates the color corresponding to a specific value.

Parameters

value

value to calculate color for

Returns

calculated color using transformer's parameters and type

Definition at line 631 of file qgspropertytransformer.cpp.

colorRamp()

QgsColorRamp * QgsColorRampTransformer::colorRamp

(

)

const

Returns the color ramp used for calculating property colors.

Returns

color ramp

See also

setColorRamp()

Definition at line 642 of file qgspropertytransformer.cpp.

loadVariant()

bool QgsColorRampTransformer::loadVariant ( const QVariant &  transformer )

overridevirtual

Loads this transformer from a QVariantMap, wrapped in a QVariant.

You can use QgsXmlUtils::readVariant to read it from an XML document.

See also

toVariant()

Reimplemented from QgsPropertyTransformer.

Definition at line 580 of file qgspropertytransformer.cpp.

nullColor()

QColor QgsColorRampTransformer::nullColor ( ) const

inline

Returns the color corresponding to a null value.

See also

setNullColor()

Definition at line 661 of file qgspropertytransformer.h.

operator=()

QgsColorRampTransformer & QgsColorRampTransformer::operator=

(

const QgsColorRampTransformer &

other

)

Definition at line 544 of file qgspropertytransformer.cpp.

rampName()

QString QgsColorRampTransformer::rampName ( ) const

inline

Returns the color ramp's name.

See also

setRampName()

Definition at line 674 of file qgspropertytransformer.h.

setColorRamp()

void QgsColorRampTransformer::setColorRamp

(

QgsColorRamp *

ramp

)

Sets the color ramp to use for calculating property colors.

Parameters

ramp	color ramp, ownership of ramp is transferred to the transformer.

See also

colorRamp()

Definition at line 647 of file qgspropertytransformer.cpp.

setNullColor()

void QgsColorRampTransformer::setNullColor ( const QColor &  color )

inline

Sets the color corresponding to a null value.

Parameters

color

null color

See also

nullColor()

Definition at line 668 of file qgspropertytransformer.h.

setRampName()

void QgsColorRampTransformer::setRampName ( const QString &  name )

inline

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

rampName()

Definition at line 682 of file qgspropertytransformer.h.

toExpression()

QString QgsColorRampTransformer::toExpression ( const QString &  baseExpression ) const

overridevirtual

Converts the transformer to a QGIS expression string.

The baseExpression string consists of a sub-expression reflecting the parent property's state.

Implements QgsPropertyTransformer.

Definition at line 618 of file qgspropertytransformer.cpp.

toVariant()

QVariant QgsColorRampTransformer::toVariant ( ) const

overridevirtual

Saves this transformer to a QVariantMap, wrapped in a QVariant.

You can use QgsXmlUtils::writeVariant to save it to an XML document.

See also

loadVariant()

Reimplemented from QgsPropertyTransformer.

Definition at line 566 of file qgspropertytransformer.cpp.

transform()

QVariant QgsColorRampTransformer::transform ( const QgsExpressionContext &  context, const QVariant &  value  ) const

overridevirtual

Calculates the transform of a value.

Derived classes must implement this to perform their transformations on input values

Parameters

context	expression context
value	input value to transform

Implements QgsPropertyTransformer.

Definition at line 597 of file qgspropertytransformer.cpp.

transformerType()

Type QgsColorRampTransformer::transformerType ( ) const

inlineoverridevirtual

Returns the transformer type.

Implements QgsPropertyTransformer.

Definition at line 629 of file qgspropertytransformer.h.

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The documentation for this class was generated from the following files:

• /build/qgis-3.28.0+99sid/src/core/qgspropertytransformer.h
• /build/qgis-3.28.0+99sid/src/core/qgspropertytransformer.cpp