QgsColorBrewerColorRamp class

Color ramp utilising "Color Brewer" preset color schemes.

Reference

Base classes

class QgsColorRamp: Abstract base class for color ramps.

Public static functions

static auto create(const QgsStringMap& properties = QgsStringMap()) -> QgsColorRamp*: Returns a new QgsColorBrewerColorRamp color ramp created using the properties encoded in a string map.
static auto listSchemeNames() -> QStringList: Returns a list of all valid color brewer scheme names.
static auto listSchemeVariants(const QString& schemeName) -> QList<int>: Returns a list of the valid variants (numbers of colors) for a specified color brewer scheme name.

Constructors, destructors, conversion operators

QgsColorBrewerColorRamp(const QString& schemeName = DEFAULT_COLORBREWER_SCHEMENAME, int colors = DEFAULT_COLORBREWER_COLORS, bool inverted = false): Constructor for QgsColorBrewerColorRamp.

Public functions

auto clone() const -> QgsColorBrewerColorRamp* override: Creates a clone of the color ramp.
auto color(double value) const -> QColor override: Returns the color corresponding to a specified value.
auto colors() const -> int: Returns the number of colors in the ramp.
auto count() const -> int override: Returns number of defined colors, or -1 if undefined.
void invert() override: Inverts the ordering of the color ramp.
auto properties() const -> QgsStringMap override: Returns a string map containing all the color ramp's properties.
auto schemeName() const -> QString: Returns the name of the color brewer color scheme.
void setColors(int colors): Sets the number of colors in the ramp.
void setSchemeName(const QString& schemeName): Sets the name of the color brewer color scheme.
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.

Protected functions

void loadPalette(): Generates the scheme using the current name and number of colors.

Function documentation

static QgsColorRamp* QgsColorBrewerColorRamp::create(const QgsStringMap& properties = QgsStringMap())

Returns a new QgsColorBrewerColorRamp color ramp created using the properties encoded in a string map.

Parameters
properties	color ramp properties

static QStringList QgsColorBrewerColorRamp::listSchemeNames()

Returns a list of all valid color brewer scheme names.

static QList<int> QgsColorBrewerColorRamp::listSchemeVariants(const QString& schemeName)

Returns a list of the valid variants (numbers of colors) for a specified color brewer scheme name.

Parameters
schemeName	color brewer scheme name

QgsColorBrewerColorRamp::QgsColorBrewerColorRamp(const QString& schemeName = DEFAULT_COLORBREWER_SCHEMENAME, int colors = DEFAULT_COLORBREWER_COLORS, bool inverted = false)

Constructor for QgsColorBrewerColorRamp.

Parameters
schemeName	color brewer scheme name
colors	number of colors in ramp
inverted	invert ramp ordering

QColor QgsColorBrewerColorRamp::color(double value) const override

Returns the color corresponding to a specified value.

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

int QgsColorBrewerColorRamp::colors() const

Returns the number of colors in the ramp.

QString QgsColorBrewerColorRamp::schemeName() const

Returns the name of the color brewer color scheme.

void QgsColorBrewerColorRamp::setColors(int colors)

Sets the number of colors in the ramp.

Parameters
colors	number of colors. Must match a valid value for the scheme, which can be retrieved using listSchemeVariants()

void QgsColorBrewerColorRamp::setSchemeName(const QString& schemeName)

Sets the name of the color brewer color scheme.

Parameters
schemeName	scheme name, must match a valid color brewer scheme name