QgsGradientColorRamp class

Gradient color ramp, which smoothly interpolates between two colors and also supports optional extra color stops.

Reference

Base classes

class QgsColorRamp: Abstract base class for color ramps.

Public static functions

static auto create(const QgsStringMap& properties = QgsStringMap()) -> QgsColorRamp*: Creates a new QgsColorRamp from a map of properties.

Constructors, destructors, conversion operators

QgsGradientColorRamp(const QColor& color1 = DEFAULT_GRADIENT_COLOR1, const QColor& color2 = DEFAULT_GRADIENT_COLOR2, bool discrete = false, const QgsGradientStopsList& stops = QgsGradientStopsList()): Constructor for QgsGradientColorRamp.

Public functions

void addStopsToGradient(QGradient* gradient, double opacity = 1): Copy color ramp stops to a QGradient.
auto clone() const -> QgsGradientColorRamp* override: Creates a clone of the color ramp.
auto color(double value) const -> QColor override: Returns the color corresponding to a specified value.
auto color1() const -> QColor: Returns the gradient start color.
auto color2() const -> QColor: Returns the gradient end color.
void convertToDiscrete(bool discrete): Converts a gradient with existing color stops to or from discrete interpolation.
auto count() const -> int override: Returns number of defined colors, or -1 if undefined.
auto info() const -> QgsStringMap: Returns any additional info attached to the gradient ramp (e.g., authorship notes)
void invert() override: Inverts the ordering of the color ramp.
auto isDiscrete() const -> bool: Returns true if the gradient is using discrete interpolation, rather than smoothly interpolating between colors.
auto properties() const -> QgsStringMap override: Returns a string map containing all the color ramp's properties.
void setColor1(const QColor& color): Sets the gradient start color.
void setColor2(const QColor& color): Sets the gradient end color.
void setDiscrete(bool discrete): Sets whether the gradient should use discrete interpolation, rather than smoothly interpolating between colors.
void setInfo(const QgsStringMap& info): Sets additional info to attach to the gradient ramp (e.g., authorship notes)
void setStops(const QgsGradientStopsList& stops): Sets the list of intermediate gradient stops for the ramp.
auto stops() const -> QgsGradientStopsList: Returns the list of intermediate gradient stops for the ramp.
auto type() const -> QString override: Returns a string representing the color ramp type.
auto value(int index) const -> double override: Returns relative value between [0,1] of color at specified index.

Function documentation

QgsGradientColorRamp::QgsGradientColorRamp(const QColor& color1 = DEFAULT_GRADIENT_COLOR1, const QColor& color2 = DEFAULT_GRADIENT_COLOR2, bool discrete = false, const QgsGradientStopsList& stops = QgsGradientStopsList())

Constructor for QgsGradientColorRamp.

Parameters
color1	start color, corresponding to a position of 0.0
color2	end color, corresponding to a position of 1.0
discrete	set to true for discrete interpolation instead of smoothly interpolating between colors
stops	optional list of additional color stops

void QgsGradientColorRamp::addStopsToGradient(QGradient* gradient, double opacity = 1)

Copy color ramp stops to a QGradient.

Parameters
gradient	gradient to copy stops into
opacity	opacity multiplier. Opacity of colors will be multiplied by this factor before adding to the gradient.

QColor QgsGradientColorRamp::color(double value) const override

Returns the color corresponding to a specified value.

Parameters
value	value between [0, 1] inclusive
Returns	color for value

QColor QgsGradientColorRamp::color1() const

Returns the gradient start color.

QColor QgsGradientColorRamp::color2() const

Returns the gradient end color.

void QgsGradientColorRamp::convertToDiscrete(bool discrete)

Converts a gradient with existing color stops to or from discrete interpolation.

Parameters
discrete	set to true to convert the gradient stops to discrete, or false to convert them to smooth interpolation

QgsStringMap QgsGradientColorRamp::info() const

Returns any additional info attached to the gradient ramp (e.g., authorship notes)

bool QgsGradientColorRamp::isDiscrete() const

Returns true if the gradient is using discrete interpolation, rather than smoothly interpolating between colors.

void QgsGradientColorRamp::setColor1(const QColor& color)

Sets the gradient start color.

Parameters
color	start color

void QgsGradientColorRamp::setColor2(const QColor& color)

Sets the gradient end color.

Parameters
color	end color

void QgsGradientColorRamp::setDiscrete(bool discrete)

Sets whether the gradient should use discrete interpolation, rather than smoothly interpolating between colors.

Parameters
discrete	set to true to use discrete interpolation

void QgsGradientColorRamp::setInfo(const QgsStringMap& info)

Sets additional info to attach to the gradient ramp (e.g., authorship notes)

Parameters
info	map of string info to attach

void QgsGradientColorRamp::setStops(const QgsGradientStopsList& stops)

Sets the list of intermediate gradient stops for the ramp.

Parameters
stops	list of stops. Any existing color stops will be replaced. The stop list will be automatically reordered so that stops are listed in ascending offset order.

QgsGradientStopsList QgsGradientColorRamp::stops() const

Returns the list of intermediate gradient stops for the ramp.