The QColor class provides colors based on RGB, HSV or CMYK values. More...

Inheritance diagram for QtGui.QColor:

Collaboration diagram for QtGui.QColor:

Public Types
enum	Spec { Cmyk = 3, Hsl = 4, Hsv = 2, Invalid = 0, Rgb = 1 }
	More...

Public Member Functions
override bool	Equals (object o)

override int	GetHashCode ()

	QColor ()


	QColor (QColor color)


	QColor (Qt.GlobalColor color)


	QColor (uint rgb)


	QColor (string name)


	QColor (QColor.Spec spec)


	QColor (int r, int g, int b, int a=255)


virtual void	CreateProxy ()

new int	Black ()


new double	BlackF ()


new QColor	ConvertTo (QColor.Spec colorSpec)


new int	Cyan ()


new double	CyanF ()


new QColor	Dark (int f=200)


new QColor	Darker (int f=200)


new void	GetCmyk (ref int c, ref int m, ref int y, ref int k)


new void	GetCmyk (ref int c, ref int m, ref int y, ref int k, ref int a)


new void	GetCmykF (ref double c, ref double m, ref double y, ref double k)


new void	GetCmykF (ref double c, ref double m, ref double y, ref double k, ref double a)


new void	GetHsl (ref int h, ref int s, ref int l)


new void	GetHsl (ref int h, ref int s, ref int l, ref int a)


new void	GetHslF (ref double h, ref double s, ref double l)


new void	GetHslF (ref double h, ref double s, ref double l, ref double a)


new void	GetHsv (ref int h, ref int s, ref int v)


new void	GetHsv (ref int h, ref int s, ref int v, ref int a)


new void	GetHsvF (ref double h, ref double s, ref double v)


new void	GetHsvF (ref double h, ref double s, ref double v, ref double a)


new void	GetRgb (ref int r, ref int g, ref int b)


new void	GetRgb (ref int r, ref int g, ref int b, ref int a)


new void	GetRgbF (ref double r, ref double g, ref double b)


new void	GetRgbF (ref double r, ref double g, ref double b, ref double a)


new int	HslHue ()


new double	HslHueF ()


new int	HslSaturation ()


new double	HslSaturationF ()


new int	HsvHue ()


new double	HsvHueF ()


new int	HsvSaturation ()


new double	HsvSaturationF ()


new int	Hue ()


new double	HueF ()


new bool	IsValid ()


new QColor	Light (int f=150)


new QColor	Lighter (int f=150)


new int	Lightness ()


new double	LightnessF ()


new int	Magenta ()


new double	MagentaF ()


new string	Name ()


new int	Saturation ()


new double	SaturationF ()


new void	SetCmyk (int c, int m, int y, int k, int a=255)


new void	SetCmykF (double c, double m, double y, double k, double a=1.0)


new void	SetHsl (int h, int s, int l, int a=255)


new void	SetHslF (double h, double s, double l, double a=1.0)


new void	SetHsv (int h, int s, int v, int a=255)


new void	SetHsvF (double h, double s, double v, double a=1.0)


new void	SetNamedColor (string name)


new void	SetRgb (int r, int g, int b, int a=255)


new void	SetRgbF (double r, double g, double b, double a=1.0)


new QColor.Spec	spec ()


new QColor	ToCmyk ()


new QColor	ToHsl ()


new QColor	ToHsv ()


new QColor	ToRgb ()


new int	Value ()


new double	ValueF ()


new int	Yellow ()


new double	YellowF ()


new void	Dispose ()

Static Public Member Functions
static System.Collections.Generic.List < string >	ColorNames ()


static QColor	FromCmyk (int c, int m, int y, int k, int a=255)


static QColor	FromCmykF (double c, double m, double y, double k, double a=1.0)


static QColor	FromHsl (int h, int s, int l, int a=255)


static QColor	FromHslF (double h, double s, double l, double a=1.0)


static QColor	FromHsv (int h, int s, int v, int a=255)


static QColor	FromHsvF (double h, double s, double v, double a=1.0)


static QColor	FromRgb (uint rgb)


static QColor	FromRgb (int r, int g, int b, int a=255)


static QColor	FromRgbF (double r, double g, double b, double a=1.0)


static QColor	FromRgba (uint rgba)


static bool	IsValidColor (string name)


static bool	operator!= (QColor arg1, QColor arg2)


static bool	operator== (QColor arg1, QColor arg2)

Protected Member Functions
	QColor (System.Type dummy)

Protected Attributes
SmokeInvocation	interceptor

Properties
new int	Alpha `[get, set]`


new double	AlphaF `[get, set]`


new int	Blue `[get, set]`


new double	BlueF `[get, set]`


new int	Green `[get, set]`


new double	GreenF `[get, set]`


new int	Red `[get, set]`


new double	RedF `[get, set]`


new uint	Rgb `[get, set]`


new uint	Rgba `[get, set]`


virtual System.IntPtr	SmokeObject `[get, set]`

Detailed Description

The QColor class provides colors based on RGB, HSV or CMYK values.

A color is normally specified in terms of RGB (red, green, and blue) components, but it is also possible to specify it in terms of HSV (hue, saturation, and value) and CMYK (cyan, magenta, yellow and black) components. In addition a color can be specified using a color name. The color name can be any of the SVG 1.0 color names.

RGBHSVCMYK

The QColor constructor creates the color based on RGB values. To create a QColor based on either HSV or CMYK values, use the toHsv() and toCmyk() functions respectively. These functions return a copy of the color using the desired format. In addition the static fromRgb(), fromHsv() and fromCmyk() functions create colors from the specified values. Alternatively, a color can be converted to any of the three formats using the convertTo() function (returning a copy of the color in the desired format), or any of the setRgb(), setHsv() and setCmyk() functions altering this color's format. The spec() function tells how the color was specified.

A color can be set by passing an RGB string (such as "#112233"), or a color name (such as "blue"), to the setNamedColor() function. The color names are taken from the SVG 1.0 color names. The name() function returns the name of the color in the format "#RRGGBB". Colors can also be set using setRgb(), setHsv() and setCmyk(). To get a lighter or darker color use the lighter() and darker() functions respectively.

The isValid() function indicates whether a QColor is legal at all. For example, a RGB color with RGB values out of range is illegal. For performance reasons, QColor mostly disregards illegal colors, and for that reason, the result of using an invalid color is undefined.

The color components can be retrieved individually, e.g with red(), hue() and cyan(). The values of the color components can also be retrieved in one go using the getRgb(), getHsv() and getCmyk() functions. Using the RGB color model, the color components can in addition be accessed with rgb().

There are several related non-members: QRgb is a typdef for an unsigned int representing the RGB value triplet (r, g, b). Note that it also can hold a value for the alpha-channel (for more information, see the Alpha-Blended Drawing section). The qRed(), qBlue() and qGreen() functions return the respective component of the given QRgb value, while the qRgb() and qRgba() functions create and return the QRgb triplet based on the given component values. Finally, the qAlpha() function returns the alpha component of the provided QRgb, and the qGray() function calculates and return a gray value based on the given value.

QColor is platform and device independent. The QColormap class maps the color to the hardware.

For more information about painting in general, see the Paint System documentation.

Integer vs. Floating Point Precision

QColor supports floating point precision and provides floating point versions of all the color components functions, e.g. getRgbF(), hueF() and fromCmykF(). Note that since the components are stored using 16-bit integers, there might be minor deviations between the values set using, for example, setRgbF() and the values returned by the getRgbF() function due to rounding.

While the integer based functions take values in the range 0-255 (except hue() which must have values within the range 0-359), the floating point functions accept values in the range 0.0 - 1.0.

Alpha-Blended Drawing

QColor also support alpha-blended outlining and filling. The alpha channel of a color specifies the transparency effect, 0 represents a fully transparent color, while 255 represents a fully opaque color. For example:

// Specify semi-transparent red

painter.setBrush(QColor(255, 0, 0, 127));

painter.drawRect(0, 0, width()/2, height());

// Specify semi-transparent blue

painter.setBrush(QColor(0, 0, 255, 127));

painter.drawRect(0, 0, width(), height()/2);

The code above produces the following output:

Alpha-blended drawing is supported on Windows, Mac OS X, and on X11 systems that have the X Render extension installed.

The alpha channel of a color can be retrieved and set using the alpha() and setAlpha() functions if its value is an integer, and alphaF() and setAlphaF() if its value is qreal (double). By default, the alpha-channel is set to 255 (opaque). To retrieve and set all the RGB color components (including the alpha-channel) in one go, use the rgba() and setRgba() functions.

Predefined Colors

There are 20 predefined QColors described by the Qt::GlobalColor enum, including black, white, primary and secondary colors, darker versions of these colors and three shades of gray. QColor also recognizes a variety of color names; the static colorNames() function returns a QStringList color names that QColor knows about.

Additionally, the Qt::color0, Qt::color1 and Qt::transparent colors are used for special purposes.

Qt::color0 (zero pixel value) and Qt::color1 (non-zero pixel value) are special colors for drawing in QBitmaps. Painting with Qt::color0 sets the bitmap bits to 0 (transparent; i.e., background), and painting with Qt::color1 sets the bits to 1 (opaque; i.e., foreground).

Qt::transparent is used to indicate a transparent pixel. When painting with this value, a pixel value will be used that is appropriate for the underlying pixel format in use.

The HSV Color Model

The RGB model is hardware-oriented. Its representation is close to what most monitors show. In contrast, HSV represents color in a way more suited to the human perception of color. For example, the relationships "stronger than", "darker than", and "the opposite of" are easily expressed in HSV but are much harder to express in RGB.

HSV, like RGB, has three components:

H, for hue, is in the range 0 to 359 if the color is chromatic (not gray), or meaningless if it is gray. It represents degrees on the color wheel familiar to most people. Red is 0 (degrees), green is 120, and blue is 240.

S, for saturation, is in the range 0 to 255, and the bigger it is, the stronger the color is. Grayish colors have saturation near 0; very strong colors have saturation near 255.

V, for value, is in the range 0 to 255 and represents lightness or brightness of the color. 0 is black; 255 is as far from black as possible.

Here are some examples: pure red is H=0, S=255, V=255; a dark red, moving slightly towards the magenta, could be H=350 (equivalent to -10), S=255, V=180; a grayish light red could have H about 0 (say 350-359 or 0-10), S about 50-100, and S=255.

Qt returns a hue value of -1 for achromatic colors. If you pass a hue value that is too large, Qt forces it into range. Hue 360 or 720 is treated as 0; hue 540 is treated as 180.

In addition to the standard HSV model, Qt provides an alpha-channel to feature alpha-blended drawing.

The HSL Color Model

HSL is similar to HSV. Instead of value parameter from HSV, HSL has the lightness parameter. The lightness parameter goes from black to color and from color to white. If you go outside at the night its black or dark gray. At day its colorful but if you look in a really strong light a things they are going to white and wash out.

The CMYK Color Model

While the RGB and HSV color models are used for display on computer monitors, the CMYK model is used in the four-color printing process of printing presses and some hard-copy devices.

CMYK has four components, all in the range 0-255: cyan (C), magenta (M), yellow (Y) and black (K). Cyan, magenta and yellow are called subtractive colors; the CMYK color model creates color by starting with a white surface and then subtracting color by applying the appropriate components. While combining cyan, magenta and yellow gives the color black, subtracting one or more will yield any other color. When combined in various percentages, these three colors can create the entire spectrum of colors.

Mixing 100 percent of cyan, magenta and yellow does produce black, but the result is unsatisfactory since it wastes ink, increases drying time, and gives a muddy colour when printing. For that reason, black is added in professional printing to provide a solid black tone; hence the term 'four color process'.

In addition to the standard CMYK model, Qt provides an alpha-channel to feature alpha-blended drawing.

See also QPalette, QBrush, and QApplication::setColorSpec().

Member Enumeration Documentation

enum QtGui.QColor.Spec

The type of color specified, either RGB, HSV, CMYK or HSL.

Constructor & Destructor Documentation

QtGui.QColor.QColor ( System.Type dummy )

protected

QtGui.QColor.QColor ( )

Constructs an invalid color with the RGB value (0, 0, 0). An invalid color is a color that is not properly set up for the underlying window system.

The alpha value of an invalid color is unspecified.

See also isValid().

QtGui.QColor.QColor ( QColor color )

Constructs a color that is a copy of color.

See also isValid().

QtGui.QColor.QColor ( Qt.GlobalColor color )

This is an overloaded function.

Constructs a new color with a color value of color.

See also isValid() and Predefined Colors.

QtGui.QColor.QColor ( uint rgb )

Constructs an invalid color with the RGB value (0, 0, 0). An invalid color is a color that is not properly set up for the underlying window system.

The alpha value of an invalid color is unspecified.

See also isValid().

QtGui.QColor.QColor ( string name )

Constructs a named color in the same way as setNamedColor() using the given name.

The color is left invalid if the name cannot be parsed.

See also setNamedColor(), name(), and isValid().

QtGui.QColor.QColor ( QColor.Spec spec )

Constructs an invalid color with the RGB value (0, 0, 0). An invalid color is a color that is not properly set up for the underlying window system.

The alpha value of an invalid color is unspecified.

See also isValid().

QtGui.QColor.QColor	(	int	r,
		int	g,
		int	b,
		int	a = `255`
	)

Constructs a color with the RGB value r, g, b, and the alpha-channel (transparency) value of a.

The color is left invalid if any of the arguments are invalid.

Member Function Documentation

new int QtGui.QColor.Black ( )

Returns the black color component of this color.

See also blackF(), getCmyk(), and The CMYK Color Model.

new double QtGui.QColor.BlackF ( )

Returns the black color component of this color.

See also black(), getCmykF(), and The CMYK Color Model.

static System.Collections.Generic.List<string> QtGui.QColor.ColorNames ( )

static

Returns a QStringList containing the color names Qt knows about.

See also setHsl().

new void QtGui.QColor.GetHsl	(	ref int	h,
		ref int	s,
		ref int	l,
		ref int	a
	)

Sets the contents pointed to by h, s, l, and a, to the hue, saturation, lightness, and alpha-channel (transparency) components of the color's HSL value.

These components can be retrieved individually using the hueHsl(), saturationHsl(), lightness() and alpha() functions.

This function was introduced in Qt 4.6.

See also setHsl().

new void QtGui.QColor.GetHslF	(	ref double	h,
		ref double	s,
		ref double	l
	)

Sets the contents pointed to by h, s, l, and a, to the hue, saturation, lightness, and alpha-channel (transparency) components of the color's HSL value.

These components can be retrieved individually using the hueHslF(), saturationHslF(), lightnessF() and alphaF() functions.

This function was introduced in Qt 4.6.

See also setHsl().

new void QtGui.QColor.GetHslF	(	ref double	h,
		ref double	s,
		ref double	l,
		ref double	a
	)

Sets the contents pointed to by h, s, l, and a, to the hue, saturation, lightness, and alpha-channel (transparency) components of the color's HSL value.

These components can be retrieved individually using the hueHslF(), saturationHslF(), lightnessF() and alphaF() functions.

This function was introduced in Qt 4.6.

See also setHsl().

new void QtGui.QColor.GetHsv	(	ref int	h,
		ref int	s,
		ref int	v
	)

Sets the contents pointed to by h, s, v, and a, to the hue, saturation, value, and alpha-channel (transparency) components of the color's HSV value.

These components can be retrieved individually using the hue(), saturation(), value() and alpha() functions.

See also setHsv() and The HSV Color Model.

new void QtGui.QColor.GetHsv	(	ref int	h,
		ref int	s,
		ref int	v,
		ref int	a
	)

Sets the contents pointed to by h, s, v, and a, to the hue, saturation, value, and alpha-channel (transparency) components of the color's HSV value.

These components can be retrieved individually using the hue(), saturation(), value() and alpha() functions.

See also setHsv() and The HSV Color Model.

new void QtGui.QColor.GetHsvF	(	ref double	h,
		ref double	s,
		ref double	v
	)

Sets the contents pointed to by h, s, v, and a, to the hue, saturation, value, and alpha-channel (transparency) components of the color's HSV value.

These components can be retrieved individually using the hueF(), saturationF(), valueF() and alphaF() functions.

See also setHsv() and The HSV Color Model.

new void QtGui.QColor.GetHsvF	(	ref double	h,
		ref double	s,
		ref double	v,
		ref double	a
	)

Sets the contents pointed to by h, s, v, and a, to the hue, saturation, value, and alpha-channel (transparency) components of the color's HSV value.

These components can be retrieved individually using the hueF(), saturationF(), valueF() and alphaF() functions.

See also setHsv() and The HSV Color Model.

new void QtGui.QColor.GetRgb	(	ref int	r,
		ref int	g,
		ref int	b
	)

Sets the contents pointed to by r, g, b, and a, to the red, green, blue, and alpha-channel (transparency) components of the color's RGB value.

These components can be retrieved individually using the red(), green(), blue() and alpha() functions.

See also rgb() and setRgb().

new void QtGui.QColor.GetRgb	(	ref int	r,
		ref int	g,
		ref int	b,
		ref int	a
	)

Sets the contents pointed to by r, g, b, and a, to the red, green, blue, and alpha-channel (transparency) components of the color's RGB value.

These components can be retrieved individually using the red(), green(), blue() and alpha() functions.

See also rgb() and setRgb().

new void QtGui.QColor.GetRgbF	(	ref double	r,
		ref double	g,
		ref double	b
	)

Sets the contents pointed to by r, g, b, and a, to the red, green, blue, and alpha-channel (transparency) components of the color's RGB value.

These components can be retrieved individually using the redF(), greenF(), blueF() and alphaF() functions.

See also rgb() and setRgb().

new void QtGui.QColor.GetRgbF	(	ref double	r,
		ref double	g,
		ref double	b,
		ref double	a
	)

Sets the contents pointed to by r, g, b, and a, to the red, green, blue, and alpha-channel (transparency) components of the color's RGB value.

These components can be retrieved individually using the redF(), greenF(), blueF() and alphaF() functions.

See also rgb() and setRgb().

new int QtGui.QColor.HslHue ( )

Returns the hue color component of this color.

This function was introduced in Qt 4.6.

Member Data Documentation

SmokeInvocation QtGui.QColor.interceptor

protected

Property Documentation

new int QtGui.QColor.Alpha

getset

Returns the alpha color component of this color.

Sets the alpha of this color to alpha. Integer alpha is specified in the range 0-255.

new double QtGui.QColor.AlphaF

getset

Returns the alpha color component of this color.

Sets the alpha of this color to alpha. qreal alpha is specified in the range 0.0-1.0.

new int QtGui.QColor.Blue

getset

Returns the blue color component of this color.

Sets the blue color component of this color to blue. Integer components are specified in the range 0-255.

new double QtGui.QColor.BlueF

getset

Returns the blue color component of this color.

Sets the blue color component of this color to blue. Float components are specified in the range 0.0-1.0.

new int QtGui.QColor.Green

getset

Returns the green color component of this color.

Sets the green color component of this color to green. Integer components are specified in the range 0-255.

new double QtGui.QColor.GreenF

getset

Returns the green color component of this color.

Sets the green color component of this color to green. Float components are specified in the range 0.0-1.0.

new int QtGui.QColor.Red

getset

Returns the red color component of this color.

Sets the red color component of this color to red. Integer components are specified in the range 0-255.

new double QtGui.QColor.RedF

getset

Returns the red color component of this color.

Sets the red color component of this color to red. Float components are specified in the range 0.0-1.0.

new uint QtGui.QColor.Rgb

getset

Returns the RGB value of the color. The alpha value is opaque.

Sets the RGB value to r, g, b and the alpha value to a.

All the values must be in the range 0-255.

new uint QtGui.QColor.Rgba

getset

Returns the RGB value of the color, including its alpha.

For an invalid color, the alpha value of the returned color is unspecified.

Sets the RGB value to rgba, including its alpha.

virtual System.IntPtr QtGui.QColor.SmokeObject

getset

Cmyk
Hsl
Hsv
Invalid
Rgb

new void QtGui.QColor.GetCmyk	(	ref int	c,
		ref int	m,
		ref int	y,
		ref int	k
	)

new void QtGui.QColor.GetCmykF	(	ref double	c,
		ref double	m,
		ref double	y,
		ref double	k
	)

new void QtGui.QColor.SetCmyk	(	int	c,
		int	m,
		int	y,
		int	k,
		int	a = `255`
	)

new void QtGui.QColor.SetCmykF	(	double	c,
		double	m,
		double	y,
		double	k,
		double	a = `1.0`
	)

new void QtGui.QColor.SetHslF	(	double	h,
		double	s,
		double	l,
		double	a = `1.0`
	)

new void QtGui.QColor.SetHsvF	(	double	h,
		double	s,
		double	v,
		double	a = `1.0`
	)

new void QtGui.QColor.SetRgbF	(	double	r,
		double	g,
		double	b,
		double	a = `1.0`
	)

Public Types

Public Member Functions

Static Public Member Functions

Protected Member Functions

Protected Attributes

Properties

Detailed Description

Member Enumeration Documentation

Constructor & Destructor Documentation

Member Function Documentation

Member Data Documentation

Property Documentation