gtkmm: Gdk::RGBA Class Reference

An RGBA color. More...

#include <gdkmm/rgba.h>

Public Member Functions
	RGBA (GdkRGBA *gobject, bool make_a_copy=true)

	RGBA (const RGBA &other)

RGBA &	operator= (const RGBA &other)

	RGBA (RGBA &&other) noexcept

RGBA &	operator= (RGBA &&other) noexcept

	~RGBA () noexcept

void	swap (RGBA &other) noexcept

GdkRGBA *	gobj ()
	Provides access to the underlying C instance.

const GdkRGBA *	gobj () const
	Provides access to the underlying C instance.

GdkRGBA *	gobj_copy () const
	Provides access to the underlying C instance. The caller is responsible for freeing it. Use when directly setting fields in structs.

	RGBA ()
	Instantiate a new Gdk::RGBA.

	RGBA (const Glib::ustring & value)
	Parses a textual representation of a color and creates a new Gdk::RGBA with the corresponding values in its `red`, `green`, `blue` and `alpha` fields.

	RGBA (float red_, float green_, float blue_, float alpha_=1.0)
	Construct a Gdk::RGBA, by specifying red, green, and blue color component values, as fractions.

void	set_grey_u (gushort value, gushort alpha=65535)
	Set a grey color, by using the same value for all color components.

void	set_grey (float g, float alpha=1.0)
	Set a grey color, by using the same value for all color components.

void	set_rgba_u (gushort red_, gushort green_, gushort blue_, gushort alpha_=65535)
	Set the color, by specifying red, green, and blue color component values.

void	set_rgba (float red_, float green_, float blue_, float alpha_=1.0)
	Set the color, by specifying red, green, and blue color component values, as fractions.

void	set_hsv (float h, float s, float v, float alpha=1.0)
	Set the color, by specifying hue, saturation, and value (brightness).

void	set_hsl (float h, float s, float l, float alpha=1.0)
	Set the color, by specifying hue, saturation, and lightness.

bool	set (const Glib::ustring &spec)
	Parses a textual representation of a color.

gushort	get_red_u () const
	Get the red component of the color.

gushort	get_green_u () const
	Get the green component of the color.

gushort	get_blue_u () const
	Get the blue component of the color.

gushort	get_alpha_u () const
	Get the alpha component of the color.

void	set_red_u (gushort value)
	Set the red component of the color.

void	set_green_u (gushort value)
	Set the green component of the color.

void	set_blue_u (gushort value)
	Set the blue component of the color.

void	set_alpha_u (gushort value)
	Set the alpha component of the color.

float	get_red () const
	Get the red component of the color, as a fraction.

float	get_green () const
	Get the green component of the color, as a fraction.

float	get_blue () const
	Get the blue component of the color, as a fraction.

float	get_alpha () const
	Get the alpha component of the color, as a fraction.

void	set_red (float value)
	Set the red component of the color, as a fraction.

void	set_green (float value)
	Set the green component of the color, as a fraction.

void	set_blue (float value)
	Set the blue component of the color, as a fraction.

void	set_alpha (float value)
	Set the alpha component of the color, as a fraction.

Glib::ustring	to_string () const
	Returns a textual specification of rgba in the form `rgb(r,g,b)` or `rgba(r,g,b,a)`, where “r”, “g”, “b” and “a” represent the red, green, blue and alpha values respectively.

bool	is_clear () const
	Checks if an rgba value is transparent.

bool	is_opaque () const
	Checks if an rgba value is opaque.

Static Public Member Functions
static GType	get_type ()
	Get the GType for this class, for use with the underlying GObject type system.

Protected Attributes
GdkRGBA *	gobject_

Related Symbols
(Note that these are not member symbols.)
bool	operator== (const RGBA &lhs, const RGBA &rhs)

bool	operator!= (const RGBA &lhs, const RGBA &rhs)

void	swap (RGBA &lhs, RGBA &rhs) noexcept

Gdk::RGBA	wrap (GdkRGBA *object, bool take_copy=false)
	A Glib::wrap() method for this object.

Detailed Description

An RGBA color.

The RGBA class is a convenient way to pass colors around. It's based on cairo's way to deal with (possibly translucent) colors and mirrors its behavior. All values are in the range from 0.0 to 1.0 inclusive. So the color (0.0, 0.0, 0.0, 0.0) represents transparent black and (1.0, 1.0, 1.0, 1.0) is opaque white. Other values will be clamped to this range when drawing.

Constructor & Destructor Documentation

◆ RGBA() [1/6]

Gdk::RGBA::RGBA	(	GdkRGBA *	gobject,
		bool	make_a_copy = `true`
	)

explicit

◆ RGBA() [2/6]

Gdk::RGBA::RGBA ( const RGBA & other )

◆ RGBA() [3/6]

Gdk::RGBA::RGBA ( RGBA && other )

noexcept

◆ ~RGBA()

Gdk::RGBA::~RGBA ( )

noexcept

◆ RGBA() [4/6]

Gdk::RGBA::RGBA ( )

Instantiate a new Gdk::RGBA.

◆ RGBA() [5/6]

Gdk::RGBA::RGBA ( const Glib::ustring & value )

explicit

Parses a textual representation of a color and creates a new Gdk::RGBA with the corresponding values in its red, green, blue and alpha fields.

The string can be one of:

A standard name (taken from the X11 rgb.txt file)
A hexadecimal value in the form rgb, rrggbb, rrrgggbbb or rrrrggggbbbb
An RGB color in the form rgb(r,g,b) (In this case the color will have full opacity)
An RGBA color in the form rgba(r,g,b,a)

Where r, g, b and a are respectively the red, green, blue and alpha color values. In the last two cases, r g and b are either integers in the range 0 to 255 or percentage values in the range 0% to 100%, and a is a floating point value in the range 0 to 1.

Parameters

value the string specifying the color.

◆ RGBA() [6/6]

Gdk::RGBA::RGBA	(	float	red_,
		float	green_,
		float	blue_,
		float	alpha_ = `1.0`
	)

Construct a Gdk::RGBA, by specifying red, green, and blue color component values, as fractions.

Parameters

red_	The red component of the color, as a fraction.
green_	The green component of the color, as a fraction.
blue_	The blue component of the color, as a fraction.
alpha_	The alpha component of the color, as a fraction.

Member Function Documentation

◆ get_alpha()

float Gdk::RGBA::get_alpha ( ) const

Get the alpha component of the color, as a fraction.

Returns: The alpha component of the color, as a fraction.

◆ get_alpha_u()

gushort Gdk::RGBA::get_alpha_u ( ) const

Get the alpha component of the color.

Returns: The alpha component of the color, in the range 0..65535.

◆ get_blue()

float Gdk::RGBA::get_blue ( ) const

Get the blue component of the color, as a fraction.

Returns: The blue component of the color, as a fraction.

◆ get_blue_u()

gushort Gdk::RGBA::get_blue_u ( ) const

Get the blue component of the color.

Returns: The blue component of the color, in the range 0..65535.

◆ get_green()

float Gdk::RGBA::get_green ( ) const

Get the green component of the color, as a fraction.

Returns: The green component of the color, as a fraction.

◆ get_green_u()

gushort Gdk::RGBA::get_green_u ( ) const

Get the green component of the color.

Returns: The green component of the color, in the range 0..65535.

◆ get_red()

float Gdk::RGBA::get_red ( ) const

Get the red component of the color, as a fraction.

Returns: The red component of the color, as a fraction.

◆ get_red_u()

gushort Gdk::RGBA::get_red_u ( ) const

Get the red component of the color.

Returns: The red component of the color, in the range 0..65535.

◆ get_type()

static GType Gdk::RGBA::get_type ( )

static

Get the GType for this class, for use with the underlying GObject type system.

◆ gobj() [1/2]

GdkRGBA * Gdk::RGBA::gobj ( )

inline

Provides access to the underlying C instance.

◆ gobj() [2/2]

const GdkRGBA * Gdk::RGBA::gobj ( ) const

inline

Provides access to the underlying C instance.

◆ gobj_copy()

GdkRGBA * Gdk::RGBA::gobj_copy ( ) const

Provides access to the underlying C instance. The caller is responsible for freeing it. Use when directly setting fields in structs.

◆ is_clear()

bool Gdk::RGBA::is_clear ( ) const

Checks if an rgba value is transparent.

That is, drawing with the value would not produce any change.

Returns: true if the rgba is clear.

◆ is_opaque()

bool Gdk::RGBA::is_opaque ( ) const

Checks if an rgba value is opaque.

That is, drawing with the value will not retain any results from previous contents.

Returns: true if the rgba is opaque.

◆ operator=() [1/2]

RGBA & Gdk::RGBA::operator= ( const RGBA & other )

◆ operator=() [2/2]

RGBA & Gdk::RGBA::operator= ( RGBA && other )

noexcept

◆ set()

bool Gdk::RGBA::set ( const Glib::ustring & spec )

Parses a textual representation of a color.

The string can be either one of:

A standard name (Taken from the CSS specification).
A hexadecimal value in the form “\rgb”, “\rrggbb”, “\rrrgggbbb” or ”\rrrrggggbbbb”
A hexadecimal value in the form “\rgba”, “\rrggbbaa”, or ”\rrrrggggbbbbaaaa”
A RGB color in the form “rgb(r,g,b)” (In this case the color will have full opacity)
A RGBA color in the form “rgba(r,g,b,a)”
A HSL color in the form "hsl(hue, saturation, lightness)"
A HSLA color in the form "hsla(hue, saturation, lightness, alpha)"

Where “r”, “g”, “b” and “a” are respectively the red, green, blue and alpha color values. In the last two cases, “r”, “g”, and “b” are either integers in the range 0 to 255 or percentage values in the range 0% to 100%, and a is a floating point value in the range 0 to 1.

Parameters

spec	The string specifying the color.

Returns: true if the parsing succeeded.

◆ set_alpha()

void Gdk::RGBA::set_alpha ( float value )

Set the alpha component of the color, as a fraction.

Parameters

value The alpha component of the color, as a fraction.

◆ set_alpha_u()

void Gdk::RGBA::set_alpha_u ( gushort value )

Set the alpha component of the color.

Parameters

value The alpha component of the color, in the range 0..65535.

◆ set_blue()

void Gdk::RGBA::set_blue ( float value )

Set the blue component of the color, as a fraction.

Parameters

value The blue component of the color, as a fraction.

◆ set_blue_u()

void Gdk::RGBA::set_blue_u ( gushort value )

Set the blue component of the color.

Parameters

value The blue component of the color, in the range 0..65535.

◆ set_green()

void Gdk::RGBA::set_green ( float value )

Set the green component of the color, as a fraction.

Parameters

value The green component of the color, as a fraction.

◆ set_green_u()

void Gdk::RGBA::set_green_u ( gushort value )

Set the green component of the color.

Parameters

value The green component of the color, in the range 0..65535.

◆ set_grey()

void Gdk::RGBA::set_grey	(	float	g,
		float	alpha = `1.0`
	)

Set a grey color, by using the same value for all color components.

Parameters

g	The value to be used for the red, green, and blue components, as a fraction.
alpha	The alpha component of the color, as a fraction.

◆ set_grey_u()

void Gdk::RGBA::set_grey_u	(	gushort	value,
		gushort	alpha = `65535`
	)

Set a grey color, by using the same value for all color components.

Parameters

value	The value to be used for the red, green, and blue components, in the range 0..65535.
alpha	The alpha component of the color, in the range 0..65535.

◆ set_hsl()

void Gdk::RGBA::set_hsl	(	float	h,
		float	s,
		float	l,
		float	alpha = `1.0`
	)

Set the color, by specifying hue, saturation, and lightness.

Parameters

h	Hue, in the range 0..360 degrees.
s	Saturation, in the range 0..1.
l	Lightness, in the range 0..1.
alpha	The alpha component of the color, in the range 0..1.

◆ set_hsv()

void Gdk::RGBA::set_hsv	(	float	h,
		float	s,
		float	v,
		float	alpha = `1.0`
	)

Set the color, by specifying hue, saturation, and value (brightness).

Parameters

h	Hue, in the range 0..360 degrees.
s	Saturation, in the range 0..1.
v	Value (a.k.a. brightness), in the range 0..1.
alpha	The alpha component of the color, in the range 0..1.

◆ set_red()

void Gdk::RGBA::set_red ( float value )

Set the red component of the color, as a fraction.

Parameters

value The red component of the color, as a fraction.

◆ set_red_u()

void Gdk::RGBA::set_red_u ( gushort value )

Set the red component of the color.

Parameters

value The red component of the color, in the range 0..65535.

◆ set_rgba()

void Gdk::RGBA::set_rgba	(	float	red_,
		float	green_,
		float	blue_,
		float	alpha_ = `1.0`
	)

Set the color, by specifying red, green, and blue color component values, as fractions.

Parameters

red_	The red component of the color, as a fraction.
green_	The green component of the color, as a fraction.
blue_	The blue component of the color, as a fraction.
alpha_	The alpha component of the color, as a fraction.

◆ set_rgba_u()

void Gdk::RGBA::set_rgba_u	(	gushort	red_,
		gushort	green_,
		gushort	blue_,
		gushort	alpha_ = `65535`
	)

Set the color, by specifying red, green, and blue color component values.

Parameters

red_	The red component of the color, in the range 0..65535.
green_	The green component of the color, in the range 0..65535.
blue_	The blue component of the color, in the range 0..65535.
alpha_	The alpha component of the color, in the range 0..65535.

◆ swap()

void Gdk::RGBA::swap ( RGBA & other )

noexcept

◆ to_string()

Glib::ustring Gdk::RGBA::to_string ( ) const

Returns a textual specification of rgba in the form rgb(r,g,b) or rgba(r,g,b,a), where “r”, “g”, “b” and “a” represent the red, green, blue and alpha values respectively.

“r”, “g”, and “b” are represented as integers in the range 0 to 255, and “a” is represented as a floating point value in the range 0 to 1.

These string forms are string forms that are supported by the CSS3 colors module, and can be parsed by parse().

Note that this string representation may lose some precision, since “r”, “g” and “b” are represented as 8-bit integers. If this is a concern, you should use a different representation.

Returns: A newly allocated text string.

Friends And Related Symbol Documentation

◆ operator!=()

bool operator!=	(	const RGBA &	lhs,
		const RGBA &	rhs
	)

Parameters

lhs	The left-hand side
rhs	The right-hand side

Returns: The result

◆ operator==()

bool operator==	(	const RGBA &	lhs,
		const RGBA &	rhs
	)

Parameters

lhs	The left-hand side
rhs	The right-hand side

Returns: The result

◆ swap()

void swap	(	RGBA &	lhs,
		RGBA &	rhs
	)

Parameters

lhs	The left-hand side
rhs	The right-hand side

◆ wrap()

Gdk::RGBA wrap	(	GdkRGBA *	object,
		bool	take_copy = `false`
	)

A Glib::wrap() method for this object.

Parameters

object	The C instance.
take_copy	False if the result should take ownership of the C instance. True if it should take a new copy or ref.

Returns: A C++ instance that wraps this C instance.

Member Data Documentation

◆ gobject_

GdkRGBA* Gdk::RGBA::gobject_

protected

Public Member Functions

Static Public Member Functions

Protected Attributes

Related Symbols

Detailed Description

Constructor & Destructor Documentation

◆ RGBA() [1/6]

◆ RGBA() [2/6]

◆ RGBA() [3/6]

◆ ~RGBA()

◆ RGBA() [4/6]

◆ RGBA() [5/6]

◆ RGBA() [6/6]

Member Function Documentation

◆ get_alpha()

◆ get_alpha_u()

◆ get_blue()

◆ get_blue_u()

◆ get_green()

◆ get_green_u()

◆ get_red()

◆ get_red_u()

◆ get_type()

◆ gobj() [1/2]

◆ gobj() [2/2]

◆ gobj_copy()

◆ is_clear()

◆ is_opaque()

◆ operator=() [1/2]

◆ operator=() [2/2]

◆ set()

◆ set_alpha()

◆ set_alpha_u()

◆ set_blue()

◆ set_blue_u()

◆ set_green()

◆ set_green_u()

◆ set_grey()

◆ set_grey_u()

◆ set_hsl()

◆ set_hsv()

◆ set_red()

◆ set_red_u()

◆ set_rgba()

◆ set_rgba_u()

◆ swap()

◆ to_string()

Friends And Related Symbol Documentation

◆ operator!=()

◆ operator==()

◆ swap()

◆ wrap()

Member Data Documentation

◆ gobject_