CopperSpice API  1.7.2
QColor Class Reference

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

Public Types

enum  Spec
 

Public Methods

 QColor ()
 
 QColor (const char *name)
 
 QColor (const QColor &other)
 
 QColor (const QString &name)
 
 QColor (int r, int g, int b, int a=255)
 
 QColor (QColor &&other)
 
 QColor (QRgb rgb)
 
 QColor (QRgba64 rgba64)
 
 QColor (Qt::GlobalColor color)
 
 QColor (Spec spec)
 
int alpha () const
 
qreal alphaF () const
 
int black () const
 
qreal blackF () const
 
int blue () const
 
qreal blueF () const
 
QColor convertTo (Spec colorSpec) const
 
int cyan () const
 
qreal cyanF () const
 
QColor dark (int factor=200) const
 
QColor darker (int factor=200) const
 
void getCmyk (int *c, int *m, int *y, int *k, int *a=nullptr)
 
void getCmykF (qreal *c, qreal *m, qreal *y, qreal *k, qreal *a=nullptr)
 
void getHsl (int *h, int *s, int *l, int *a=nullptr) const
 
void getHslF (qreal *h, qreal *s, qreal *l, qreal *a=nullptr) const
 
void getHsv (int *h, int *s, int *v, int *a=nullptr) const
 
void getHsvF (qreal *h, qreal *s, qreal *v, qreal *a=nullptr) const
 
void getRgb (int *r, int *g, int *b, int *a=nullptr) const
 
void getRgbF (qreal *r, qreal *g, qreal *b, qreal *a=nullptr) const
 
int green () const
 
qreal greenF () const
 
int hslHue () const
 
qreal hslHueF () const
 
int hslSaturation () const
 
qreal hslSaturationF () const
 
int hsvHue () const
 
qreal hsvHueF () const
 
int hsvSaturation () const
 
qreal hsvSaturationF () const
 
int hue () const
 
qreal hueF () const
 
bool isValid () const
 
QColor light (int f=150) const
 
QColor lighter (int f=150) const
 
int lightness () const
 
qreal lightnessF () const
 
int magenta () const
 
qreal magentaF () const
 
QString name (NameFormat format=HexRgb) const
 
 operator QVariant () const
 
bool operator!= (const QColor &color) const
 
QColor & operator= (Qt::GlobalColor color)
 
bool operator== (const QColor &color) const
 
int red () const
 
qreal redF () const
 
QRgb rgb () const
 
QRgb rgba () const
 
QRgba64 rgba64 () const
 
int saturation () const
 
qreal saturationF () const
 
void setAlpha (int alpha)
 
void setAlphaF (qreal alpha)
 
void setBlue (int blue)
 
void setBlueF (qreal blue)
 
void setCmyk (int c, int m, int y, int k, int a=255)
 
void setCmykF (qreal c, qreal m, qreal y, qreal k, qreal a=1.0)
 
void setGreen (int green)
 
void setGreenF (qreal green)
 
void setHsl (int h, int s, int l, int a=255)
 
void setHslF (qreal h, qreal s, qreal l, qreal a=1.0)
 
void setHsv (int h, int s, int v, int a=255)
 
void setHsvF (qreal h, qreal s, qreal v, qreal a=1.0)
 
void setNamedColor (const QString &name)
 
void setRed (int red)
 
void setRedF (qreal red)
 
void setRgb (int r, int g, int b, int a=255)
 
void setRgb (QRgb rgb)
 
void setRgba (QRgb rgba)
 
void setRgba64 (QRgba64 rgba)
 
void setRgbF (qreal r, qreal g, qreal b, qreal a=1.0)
 
Spec spec () const
 
QColor toCmyk () const
 
QColor toHsl () const
 
QColor toHsv () const
 
QColor toRgb () const
 
int value () const
 
qreal valueF () const
 
int yellow () const
 
qreal yellowF () const
 

Static Public Methods

static QStringList colorNames ()
 
static QColor fromCmyk (int c, int m, int y, int k, int a=255)
 
static QColor fromCmykF (qreal c, qreal m, qreal y, qreal k, qreal a=1.0)
 
static QColor fromHsl (int h, int s, int l, int a=255)
 
static QColor fromHslF (qreal h, qreal s, qreal l, qreal a=1.0)
 
static QColor fromHsv (int h, int s, int v, int a=255)
 
static QColor fromHsvF (qreal h, qreal s, qreal v, qreal a=1.0)
 
static QColor fromRgb (int r, int g, int b, int a=255)
 
static QColor fromRgb (QRgb rgb)
 
static QColor fromRgba (QRgb rgba)
 
static QColor fromRgba64 (QRgba64 rgba)
 
static QColor fromRgba64 (ushort r, ushort g, ushort b, ushort a=USHRT_MAX)
 
static QColor fromRgbF (qreal r, qreal g, qreal b, qreal a=1.0)
 
static bool isValidColor (const QString &name)
 

Friends

QDataStreamoperator<< (QDataStream &, const QColor &)
 
QDataStreamoperator>> (QDataStream &, QColor &)
 
class QColormap
 

Related Functions

These are not member functions

int qAlpha (QRgb rgba)
 
int qBlue (QRgb rgb)
 
int qGray (int r, int g, int b)
 
int qGray (QRgb rgb)
 
int qGreen (QRgb rgb)
 
int qRed (QRgb rgb)
 
typedef QRgb
 
QRgb qRgb (int r, int g, int b)
 
QRgb qRgba (int r, int g, int b, int a)
 

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().

QRgb is a typedef for an unsigned int representing the RGB value triplet (r, g, b). It can hold a value for the alpha-channel. For more information refer to 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 refer to the Paint System documentation.

Integer versus 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.

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 where as a grayish light red could have H about 0 (say 350-359 or 0-10), S about 50-100, and S=255.

For achromatic color the hue value returned is -1. If you pass a hue value that is too large, it will reset into range. Hue 360 or 720 is treated as 0, hue 540 is treated as 180.

In addition to the standard HSV model there is also an alpha-channel feature Alpha-Blended Drawing.

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.

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 color 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 there is also an alpha-channel to feature Alpha-Blended Drawing.

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

Member Enumeration Documentation

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

ConstantValue
QColor::Rgb1
QColor::Hsv2
QColor::Cmyk3
QColor::Hsl4
QColor::Invalid0
See also
spec(), convertTo()

Constructor & Destructor Documentation

QColor::QColor ( const QColor &  other)

Copy constructs a new QColor from other.

See also
isValid()
QColor::QColor ( QColor &&  other)

Move constructs a new QColor other.

See also
isValid()
QColor::QColor ( )
inline

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()
QColor::QColor ( Qt::GlobalColor  color)

Constructs a new QColor with a color value of color.

See also
isValid(), Predefined Colors
QColor::QColor ( int  r,
int  g,
int  b,
int  a = 255 
)
inline

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.

See also
setRgba(), isValid()
QColor::QColor ( QRgb  rgb)

Constructs a color with the value rgb. The alpha component is ignored and set to solid.

See also
fromRgb(), isValid()
QColor::QColor ( QRgba64  rgba64)

Constructs a color with the given rgba64 value.

QColor::QColor ( const QString name)
inline

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

The color is left invalid if the name can not be parsed.

See also
setNamedColor(), name(), isValid()
QColor::QColor ( const char *  name)
inline

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

The color is left invalid if the name can not be parsed.

See also
setNamedColor(), name(), isValid()
QColor::QColor ( Spec  spec)

Constructs a color with the given spec enum value.

Method Documentation

int QColor::alpha ( ) const

Returns the alpha color component of this color.

See also
setAlpha(), alphaF(), Alpha-Blended Drawing
qreal QColor::alphaF ( ) const

Returns the alpha color component of this color.

See also
setAlphaF(), alpha(), Alpha-Blended Drawing
int QColor::black ( ) const

Returns the black color component of this color.

See also
blackF(), getCmyk(), CMYK Color Model
qreal QColor::blackF ( ) const

Returns the black color component of this color.

See also
black(), getCmykF(), CMYK Color Model
int QColor::blue ( ) const

Returns the blue color component of this color.

See also
setBlue(), blueF(), getRgb()
qreal QColor::blueF ( ) const

Returns the blue color component of this color.

See also
setBlueF(), blue(), getRgbF()
QStringList QColor::colorNames ( )
static

Returns a QStringList containing the color names CopperSpice knows about.

See also
Predefined Colors
QColor QColor::convertTo ( Spec  colorSpec) const

Creates a copy of this color in the format specified by colorSpec.

See also
spec(), toCmyk(), toHsv(), toRgb(), isValid()
int QColor::cyan ( ) const

Returns the cyan color component of this color.

See also
cyanF(), getCmyk(), CMYK Color Model
qreal QColor::cyanF ( ) const

Returns the cyan color component of this color.

See also
cyan(), getCmykF(), CMYK Color Model
QColor QColor::dark ( int  factor = 200) const
deprecated
Deprecated:
Use darker(factor) instead.
QColor QColor::darker ( int  f = 200) const
inline

Returns a darker (or lighter) color, but does not change this object.

If the factor is greater than 100, this functions returns a darker color. Setting factor to 300 returns a color that has one-third the brightness. If the factor is less than 100, the return color is lighter, but we recommend using the lighter() function for this purpose. If the factor is 0 or negative, the return value is unspecified.

The function converts the current RGB color to HSV, divides the value (V) component by factor and converts the color back to RGB.

See also
lighter(), isValid()
QColor QColor::fromCmyk ( int  c,
int  m,
int  y,
int  k,
int  a = 255 
)
static

Static convenience function that returns a QColor constructed from the given CMYK color values: c (cyan), m (magenta), y (yellow), k (black), and a (alpha-channel, i.e. transparency).

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

See also
toCmyk(), fromCmykF(), isValid(), CMYK Color Model
QColor QColor::fromCmykF ( qreal  c,
qreal  m,
qreal  y,
qreal  k,
qreal  a = 1.0 
)
static

Static convenience function that returns a QColor constructed from the given CMYK color values: c (cyan), m (magenta), y (yellow), k (black), and a (alpha-channel, i.e. transparency).

All the values must be in the range 0.0 to 1.0.

See also
toCmyk(), fromCmyk(), isValid(), CMYK Color Model
QColor QColor::fromHsl ( int  h,
int  s,
int  l,
int  a = 255 
)
static

Static convenience function that returns a QColor constructed from the HSV color values, h (hue), s (saturation), l (lightness), and a (alpha-channel, i.e. transparency).

The value of s, l, and a must all be in the range 0-255; the value of h must be in the range 0-359.

See also
toHsl(), fromHslF(), isValid()
QColor QColor::fromHslF ( qreal  h,
qreal  s,
qreal  l,
qreal  a = 1.0 
)
static

Static convenience function that returns a QColor constructed from the HSV color values, h (hue), s (saturation), l (lightness), and a (alpha-channel, i.e. transparency).

All the values must be in the range 0.0 to 1.0.

See also
toHsl(), fromHsl(), isValid()
QColor QColor::fromHsv ( int  h,
int  s,
int  v,
int  a = 255 
)
static

Static convenience function that returns a QColor constructed from the HSV color values, h (hue), s (saturation), v (value), and a (alpha-channel, i.e. transparency).

The value of s, v, and a must all be in the range 0-255; the value of h must be in the range 0-359.

See also
toHsv(), fromHsvF(), isValid(), HSV Color Model
QColor QColor::fromHsvF ( qreal  h,
qreal  s,
qreal  v,
qreal  a = 1.0 
)
static

Static convenience function that returns a QColor constructed from the HSV color values, h (hue), s (saturation), v (value), and a (alpha-channel, i.e. transparency).

All the values must be in the range 0.0 to 1.0.

See also
toHsv(), fromHsv(), isValid(), HSV Color Model
QColor QColor::fromRgb ( int  r,
int  g,
int  b,
int  a = 255 
)
static

Static convenience function that returns a QColor constructed from the RGB color values, r (red), g (green), b (blue), and a (alpha-channel, i.e. transparency).

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

See also
toRgb(), fromRgbF(), isValid()
QColor QColor::fromRgb ( QRgb  rgb)
static

Static convenience function that returns a QColor constructed from the given QRgb value rgb.

The alpha component of rgb is ignored (i.e. it is automatically set to 255), use the fromRgba() function to include the alpha-channel specified by the given QRgb value.

See also
fromRgba(), fromRgbF(), toRgb(), isValid()
QColor QColor::fromRgba ( QRgb  rgba)
static

Static convenience function that returns a QColor constructed from the given QRgb value rgba.

Unlike the fromRgb() function, the alpha-channel specified by the given QRgb value is included.

See also
fromRgb(), isValid()
QColor QColor::fromRgba64 ( QRgba64  rgba)
static

Static convenience function that returns a QColor constructed from the given QRgba64 value rgba64.

See also
fromRgb(), fromRgbF(), toRgb(), isValid()
QColor QColor::fromRgba64 ( ushort  r,
ushort  g,
ushort  b,
ushort  a = USHRT_MAX 
)
static

Static convenience function that returns a QColor constructed from the RGBA64 color values, r (red), g (green), b (blue), and a (alpha-channel, i.e. transparency).

See also
fromRgb(), fromRgbF(), toRgb(), isValid()
QColor QColor::fromRgbF ( qreal  r,
qreal  g,
qreal  b,
qreal  a = 1.0 
)
static

Static convenience function that returns a QColor constructed from the RGB color values, r (red), g (green), b (blue), and a (alpha-channel, i.e. transparency).

All the values must be in the range 0.0 to 1.0.

See also
fromRgb(), toRgb(), isValid()
void QColor::getCmyk ( int *  c,
int *  m,
int *  y,
int *  k,
int *  a = nullptr 
)

Sets the contents pointed to by c, m, y, k, and a, to the cyan, magenta, yellow, black, and alpha-channel (transparency) components of the color's CMYK value.

These components can be retrieved individually using the cyan(), magenta(), yellow(), black() and alpha() functions.

See also
setCmyk(), CMYK Color Model
void QColor::getCmykF ( qreal c,
qreal m,
qreal y,
qreal k,
qreal a = nullptr 
)

Sets the contents pointed to by c, m, y, k, and a, to the cyan, magenta, yellow, black, and alpha-channel (transparency) components of the color's CMYK value.

These components can be retrieved individually using the cyanF(), magentaF(), yellowF(), blackF() and alphaF() functions.

See also
setCmykF(), CMYK Color Model
void QColor::getHsl ( int *  h,
int *  s,
int *  l,
int *  a = nullptr 
) const

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 hslHue(), hslSaturation(), lightness() and alpha() functions.

See also
setHsl()
void QColor::getHslF ( qreal h,
qreal s,
qreal l,
qreal a = nullptr 
) const

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 hslHueF(), hslSaturationF(), lightnessF() and alphaF() functions.

See also
setHsl()
void QColor::getHsv ( int *  h,
int *  s,
int *  v,
int *  a = nullptr 
) const

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(), HSV Color Model
void QColor::getHsvF ( qreal h,
qreal s,
qreal v,
qreal a = nullptr 
) const

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(), HSV Color Model
void QColor::getRgb ( int *  r,
int *  g,
int *  b,
int *  a = nullptr 
) const

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(), setRgb()
void QColor::getRgbF ( qreal r,
qreal g,
qreal b,
qreal a = nullptr 
) const

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(), setRgb()
int QColor::green ( ) const

Returns the green color component of this color.

See also
setGreen(), greenF(), getRgb()
qreal QColor::greenF ( ) const

Returns the green color component of this color.

See also
setGreenF(), green(), getRgbF()
int QColor::hslHue ( ) const

Returns the hue color component of this color.

See also
getHslF(), getHsl()
qreal QColor::hslHueF ( ) const

Returns the hue color component of this color.

See also
hue(), getHslF()
int QColor::hslSaturation ( ) const

Returns the saturation color component of this color.

See also
saturationF(), getHsv(), HSV Color Model
qreal QColor::hslSaturationF ( ) const

Returns the saturation color component of this color.

See also
saturationF(), getHslF()
int QColor::hsvHue ( ) const

Returns the hue color component of this color.

See also
hueF(), getHsv(), HSV Color Model
qreal QColor::hsvHueF ( ) const

Returns the hue color component of this color.

See also
hue(), getHsvF(), HSV Color Model
int QColor::hsvSaturation ( ) const

Returns the saturation color component of this color.

See also
saturationF(), getHsv(), HSV Color Model
qreal QColor::hsvSaturationF ( ) const

Returns the saturation color component of this color.

See also
saturation(), getHsvF(), HSV Color Model
int QColor::hue ( ) const

Returns the hue color component of this color.

The color is implicitly converted to HSV.

See also
hsvHue(), hueF(), getHsv(), HSV Color Model
qreal QColor::hueF ( ) const

Returns the hue color component of this color.

The color is implicitly converted to HSV.

See also
hsvHueF(), hue(), getHsvF(), HSV Color Model
bool QColor::isValid ( ) const
inline

Returns true if the color is valid, otherwise returns false.

bool QColor::isValidColor ( const QString name)
static

Returns true if the name is a valid color name and can be used to construct a valid QColor object, otherwise returns false.

It uses the same algorithm used in setNamedColor().

See also
setNamedColor()
QColor QColor::light ( int  factor = 150) const
deprecated
Deprecated:
Use lighter(factor) instead.
QColor QColor::lighter ( int  f = 150) const
inline

Returns a lighter (or darker) color, but does not change this object.

If the factor is greater than 100, this functions returns a lighter color. Setting factor to 150 returns a color that is 50% brighter. If the factor is less than 100, the return color is darker, but we recommend using the darker() function for this purpose. If the factor is 0 or negative, the return value is unspecified.

The function converts the current RGB color to HSV, multiplies the value (V) component by factor and converts the color back to RGB.

See also
darker(), isValid()
int QColor::lightness ( ) const

Returns the lightness color component of this color.

See also
lightnessF(), getHsl()
qreal QColor::lightnessF ( ) const

Returns the lightness color component of this color.

See also
value(), getHslF()
int QColor::magenta ( ) const

Returns the magenta color component of this color.

See also
magentaF(), getCmyk(), CMYK Color Model
qreal QColor::magentaF ( ) const

Returns the magenta color component of this color.

See also
magenta(), getCmykF(), CMYK Color Model
QString QColor::name ( NameFormat  format = HexRgb) const

Returns the name of the color in the specified format. The default format is "\#RRGGBB". For example, a "\#" character followed by three two-digit hexadecimal numbers.

See also
setNamedColor()
QColor::operator QVariant ( ) const

Returns the color as a QVariant

bool QColor::operator!= ( const QColor &  color) const

Returns true if this color has a different RGB and alpha values from color, otherwise returns false.

QColor & QColor::operator= ( Qt::GlobalColor  color)

Assigns a copy of color to this color, and returns a reference to it.

Assigns a copy of color and returns a reference to this color.

bool QColor::operator== ( const QColor &  color) const

Returns true if this color has the same RGB and alpha values as color, otherwise returns false.

int QColor::red ( ) const

Returns the red color component of this color.

See also
setRed(), redF(), getRgb()
qreal QColor::redF ( ) const

Returns the red color component of this color.

See also
setRedF(), red(), getRgbF()
QRgb QColor::rgb ( ) const

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

See also
setRgb(), getRgb(), rgba()
QRgb QColor::rgba ( ) const

Returns the RGB value of the color, including its alpha. For an invalid color, the alpha value of the returned color is unspecified.

See also
setRgba(), rgb()
QRgba64 QColor::rgba64 ( ) const

Returns the RGB64 value of the color, including its alpha. For an invalid color, the alpha value of the returned color is unspecified.

See also
setRgba64(), rgba(), rgb()
int QColor::saturation ( ) const

Returns the saturation color component of this color.

The color is implicitly converted to HSV.

See also
hsvSaturation(), saturationF(), getHsv(), HSV Color Model
qreal QColor::saturationF ( ) const

Returns the saturation color component of this color.

The color is implicitly converted to HSV.

See also
hsvSaturationF(), saturation(), getHsvF(), HSV Color Model
void QColor::setAlpha ( int  alpha)

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

See also
alpha(), alphaF(), Alpha-Blended Drawing
void QColor::setAlphaF ( qreal  alpha)

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

See also
alphaF(), alpha(), Alpha-Blended Drawing
void QColor::setBlue ( int  blue)

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

See also
blue(), blueF(), setRgb()
void QColor::setBlueF ( qreal  blue)

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

See also
blueF(), blue(), setRgbF()
void QColor::setCmyk ( int  c,
int  m,
int  y,
int  k,
int  a = 255 
)

Sets the color to CMYK values, c (cyan), m (magenta), y (yellow), k (black), and a (alpha-channel, i.e. transparency).

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

See also
getCmyk(), setCmykF(), CMYK Color Model
void QColor::setCmykF ( qreal  c,
qreal  m,
qreal  y,
qreal  k,
qreal  a = 1.0 
)

Sets the color to CMYK values, c (cyan), m (magenta), y (yellow), k (black), and a (alpha-channel, i.e. transparency).

All the values must be in the range 0.0 to 1.0.

See also
getCmykF(), setCmyk(), CMYK Color Model
void QColor::setGreen ( int  green)

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

See also
green(), greenF(), setRgb()
void QColor::setGreenF ( qreal  green)

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

See also
greenF(), green(), setRgbF()
void QColor::setHsl ( int  h,
int  s,
int  l,
int  a = 255 
)

Sets a HSL color value. h is the hue, s is the saturation, l is the lightness and a is the alpha component of the HSL color.

The saturation, value and alpha-channel values must be in the range 0-255, and the hue value must be greater than -1.

See also
getHsl(), setHslF()
void QColor::setHslF ( qreal  h,
qreal  s,
qreal  l,
qreal  a = 1.0 
)

Sets a HSL color lightness. h is the hue, s is the saturation, l is the lightness and a is the alpha component of the HSL color.

All the values must be in the range 0.0 to 1.0.

See also
getHslF(), setHsl()
void QColor::setHsv ( int  h,
int  s,
int  v,
int  a = 255 
)

Sets a HSV color value. h is the hue, s is the saturation, v is the value and a is the alpha component of the HSV color.

The saturation, value and alpha-channel values must be in the range 0-255, and the hue value must be greater than -1.

See also
getHsv(), setHsvF(), HSV Color Model
void QColor::setHsvF ( qreal  h,
qreal  s,
qreal  v,
qreal  a = 1.0 
)

Sets a HSV color value. h is the hue, s is the saturation, v is the value and a is the alpha component of the HSV color.

All the values must be in the range 0.0 to 1.0.

See also
getHsvF(), setHsv(), HSV Color Model.
void QColor::setNamedColor ( const QString name)

Sets the RGB value of this QColor to name, which may be in one of the following formats. The color is invalid if name can not be parsed.

  • #RGB (each of R, G, and B is a single hex digit)
  • #RRGGBB
  • #RRRGGGBBB
  • #RRRRGGGGBBBB
  • A name from the list of colors defined in the list of SVG color keyword names provided by the World Wide Web Consortium. For example, "steelblue" or "gainsboro". These color names work on all platforms.
    Color names are not the same as those defined by the Qt::GlobalColor enums. For example, "green" and Qt::green does not refer to the same color.
  • "transparent" which represents the absence of a color.
See also
QColor(), name(), isValid()
void QColor::setRed ( int  red)

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

See also
red(), redF(), setRgb()
void QColor::setRedF ( qreal  red)

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

See also
redF(), red(), setRgbF()
void QColor::setRgb ( int  r,
int  g,
int  b,
int  a = 255 
)

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

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

See also
rgb(), getRgb(), setRgbF()
void QColor::setRgb ( QRgb  rgb)

Sets the RGB value to rgb. The alpha value is set to opaque.

void QColor::setRgba ( QRgb  rgba)

Sets the RGB value to rgba, including its alpha.

See also
rgba(), rgb()
void QColor::setRgba64 ( QRgba64  rgba)

Sets the RGB value to rgba, including its alpha.

See also
rgba(), rgb(), setRgba64()
void QColor::setRgbF ( qreal  r,
qreal  g,
qreal  b,
qreal  a = 1.0 
)

Sets the color channels of this color to r (red), g (green), b (blue) and a (alpha, transparency).

All values must be in the range 0.0 to 1.0.

See also
rgb(), getRgbF(), setRgb()
Spec QColor::spec ( ) const
inline

Returns how the color was specified.

See also
Spec, convertTo()
QColor QColor::toCmyk ( ) const

Creates and returns a CMYK QColor based on this color.

See also
fromCmyk(), convertTo(), isValid(), CMYK Color Model
QColor QColor::toHsl ( ) const

Creates and returns an HSL QColor based on this color.

See also
fromHsl(), convertTo(), isValid()
QColor QColor::toHsv ( ) const

Creates and returns an HSV QColor based on this color.

See also
fromHsv(), convertTo(), isValid(), HSV Color Model
QColor QColor::toRgb ( ) const

Create and returns an RGB QColor based on this color.

See also
fromRgb(), convertTo(), isValid()
int QColor::value ( ) const

Returns the value color component of this color.

See also
valueF(), getHsv(), HSV Color Model
qreal QColor::valueF ( ) const

Returns the value color component of this color.

See also
value(), getHsvF(), HSV Color Model
int QColor::yellow ( ) const

Returns the yellow color component of this color.

See also
yellowF(), getCmyk(), CMYK Color Model
qreal QColor::yellowF ( ) const

Returns the yellow color component of this color.

See also
yellow(), getCmykF(), CMYK Color Model

Friends And Related Function Documentation

QDataStream & operator<< ( QDataStream stream,
const QColor &  color 
)
friend

Writes the color to the stream.

See also
Refer to Serializing Data Types for additional information
QDataStream & operator>> ( QDataStream stream,
QColor &  color 
)
friend

Reads the color from the stream.

See also
Refer to Serializing Data Types for additional information
int qAlpha ( QRgb  rgba)
related

Returns the alpha component of the ARGB quadruplet rgba.

See also
qRgb(), QColor::alpha()
int qBlue ( QRgb  rgb)
related

Returns the blue component of the ARGB quadruplet rgb.

See also
qRgb(), QColor::blue()
int qGray ( int  r,
int  g,
int  b 
)
related

Returns a gray value (0 to 255) from the (r, g, b) triplet.

The gray value is calculated using the formula (r * 11 + g * 16 + b * 5)/32.

int qGray ( QRgb  rgb)
related

Returns a gray value (0 to 255) from the given ARGB quadruplet rgb.

The gray value is calculated using the formula (R * 11 + G * 16 + B * 5)/32; the alpha-channel is ignored.

int qGreen ( QRgb  rgb)
related

Returns the green component of the ARGB quadruplet rgb.

See also
qRgb(), QColor::green()
int qRed ( QRgb  rgb)
related

Returns the red component of the ARGB quadruplet rgb.

See also
qRgb(), QColor::red()
typedef QRgb ( )
related

An ARGB quadruplet on the format #AARRGGBB, equivalent to an unsigned int.

The type also holds a value for the alpha-channel. The default alpha channel is ff is opaque. For more information refer to the Alpha-Blended Drawing section.

See also
QColor::rgb(), QColor::rgba()
QRgb qRgb ( int  r,
int  g,
int  b 
)
related

Returns the ARGB quadruplet (255, r, g, b).

See also
qRgb(), qRed(), qGreen(), qBlue()
QRgb qRgba ( int  r,
int  g,
int  b,
int  a 
)
related

Returns the ARGB quadruplet (a, r, g, b).

See also
qRgb(), qRed(), qGreen(), qBlue()