KColorUtils Namespace Reference

from PyKDE4.kdeui.KColorUtils import *

Detailed Description

A set of methods used to work with colors.

Functions
float	contrastRatio (QColor a0, QColor a1)
QColor	darken (QColor a0, float amount=0.5, float chromaGain=1.0)
QColor	lighten (QColor a0, float amount=0.5, float chromaInverseGain=1.0)
float	luma (QColor a0)
QColor	mix (QColor c1, QColor c2, float bias=0.5)
QColor	overlayColors (QColor base, QColor paint, QPainter::CompositionMode comp=QPainter.CompositionMode_SourceOver)
QColor	shade (QColor a0, float lumaAmount, float chromaAmount=0.0)
QColor	tint (QColor base, QColor color, float amount=0.3)

Function Documentation

float contrastRatio	(	QColor	a0,
		QColor	a1
	)

Calculate the contrast ratio between two colors, according to the W3C/WCAG2.0 algorithm, (Lmax + 0.05)/(Lmin + 0.05), where Lmax and Lmin are the luma values of the lighter color and the darker color, respectively.

A contrast ration of 5:1 (result == 5.0) is the minimum for "normal" text to be considered readable (large text can go as low as 3:1). The ratio ranges from 1:1 (result == 1.0) to 21:1 (result == 21.0).

See also:: KColorUtils.luma

QColor darken	(	QColor	a0,
		float	amount=0.5,
		float	chromaGain=1.0
	)

Adjust the luma of a color by changing its distance from black.

amount == 1.0 gives black

amount == 0.5 results in a color whose luma is halfway between 0.0

and that of the original color

amount == 0.0 gives the original color

amount == -1.0 gives a color that is 'twice as far from black' as

the original color, that is luma(result) == 2*luma(color)

Parameters:

	amount	factor by which to adjust the luma component of the color
	chromaGain	(optional) factor by which to adjust the chroma component of the color; 1.0 means no change, 0.0 minimizes chroma

See also:: KColorUtils.shade

QColor lighten	(	QColor	a0,
		float	amount=0.5,
		float	chromaInverseGain=1.0
	)

Adjust the luma of a color by changing its distance from white.

amount == 1.0 gives white

amount == 0.5 results in a color whose luma is halfway between 1.0

and that of the original color

amount == 0.0 gives the original color

amount == -1.0 gives a color that is 'twice as far from white' as

the original color, that is luma(result) == 1.0 - 2*(1.0 - luma(color))

Parameters:

	amount	factor by which to adjust the luma component of the color
	chromaInverseGain	(optional) factor by which to adjust the chroma component of the color; 1.0 means no change, 0.0 maximizes chroma

See also:: KColorUtils.shade

float luma	(	QColor	a0
	)

Calculate the luma of a color. Luma is weighted sum of gamma-adjusted R'G'B' components of a color. The result is similar to qGray. The range is from 0.0 (black) to 1.0 (white).

KColorUtils.darken(), KColorUtils.lighten() and KColorUtils.shade() operate on the luma of a color.

See also:: http://en.wikipedia.org/wiki/Luma_(video)

QColor mix	(	QColor	c1,
		QColor	c2,
		float	bias=0.5
	)

Blend two colors into a new color by linear combination.

QColor lighter = KColorUtils.mix(myColor, Qt.white)

Parameters:

	c1	first color.
	c2	second color.
	bias	weight to be used for the mix. bias <= 0 gives c1, bias >= 1 gives c2. bias == 0.5 gives a 50% blend of c1 and c2.

QColor overlayColors	(	QColor	base,
		QColor	paint,
		QPainter::CompositionMode	comp=QPainter.CompositionMode_SourceOver
	)

Blend two colors into a new color by painting the second color over the first using the specified composition mode.

QColor white(Qt.white);
white.setAlphaF(0.5);
QColor lighter = KColorUtils.overlayColors(myColor, white);

Parameters:

	base	the base color (alpha channel is ignored).
	paint	the color to be overlayed onto the base color.
	comp	the CompositionMode used to do the blending.

QColor shade	(	QColor	a0,
		float	lumaAmount,
		float	chromaAmount=0.0
	)

Adjust the luma and chroma components of a color. The amount is added to the corresponding component.

Parameters:

	lumaAmount	amount by which to adjust the luma component of the color; 0.0 results in no change, -1.0 turns anything black, 1.0 turns anything white
	chromaAmount	(optional) amount by which to adjust the chroma component of the color; 0.0 results in no change, -1.0 minimizes chroma, 1.0 maximizes chroma

See also:: KColorUtils.luma

QColor tint	(	QColor	base,
		QColor	color,
		float	amount=0.3
	)

Create a new color by tinting one color with another. This function is meant for creating additional colors withing the same class (background, foreground) from colors in a different class. Therefore when amount is low, the luma of base is mostly preserved, while the hue and chroma of color is mostly inherited.

Parameters:

	base	color to be tinted
	color	color with which to tint
	amount	how strongly to tint the base; 0.0 gives base, 1.0 gives color

KColorUtils Namespace Reference

Detailed Description

Functions

Function Documentation

Modules