Gdk::Colormap Class Reference

#include <colormap.h>

Inheritance diagram for Gdk::Colormap:

Public Member Functions
virtual	~Colormap ()
GdkColormap *	gobj ()
	Provides access to the underlying C GObject. More...
const GdkColormap *	gobj () const
	Provides access to the underlying C GObject. More...
GdkColormap *	gobj_copy ()
	Provides access to the underlying C instance. The caller is responsible for unrefing it. Use when directly setting fields in structs. More...
int	alloc_colors (ArrayHandle_Color &colors, int ncolors, bool writeable, bool best_match, Glib::ArrayHandle< bool > &success)
void	free_colors (Color &colors, int ncolors)
bool	alloc_color (Color &color, bool writeable=false, bool best_match=true)
void	free_color (Color &color)
void	query_color (gulong pixel, Color &result)
Glib::RefPtr< Visual >	get_visual ()
Glib::RefPtr< const Visual >	get_visual () const
Glib::RefPtr< Screen >	get_screen ()
Glib::RefPtr< const Screen >	get_screen () const

Static Public Member Functions
static GType	get_type () G_GNUC_CONST
static Glib::RefPtr< Colormap >	create (const Glib::RefPtr< Visual > &visual, bool allocate)
static Glib::RefPtr< Colormap >	get_system ()

Protected Member Functions
	Colormap (const Glib::RefPtr< Visual > &visual, bool allocate)

Related Functions
(Note that these are not member functions.)
Glib::RefPtr< Gdk::Colormap >	wrap (GdkColormap *object, bool take_copy=false)

Detailed Description

A Colormap is an object that contains the mapping between the color values stored in memory and the RGB values that are used to display color values. In general, colormaps only contain significant information for pseudo-color visuals, but even for other visual types, a colormap object is required in some circumstances.

There are a couple of special colormaps that can be retrieved. The system colormap (retrieved with get_system()) is the default colormap of the system. If you are using GdkRGB, there is another colormap that is important - the colormap in which GdkRGB works, retrieved with Gdk::rgb_get_colormap(). However, when using GdkRGB, it is not generally necessary to allocate colors directly.

Definition at line 66 of file colormap.h.

Constructor & Destructor Documentation

~Colormap()

virtual Gdk::Colormap::~Colormap ( )

virtual

Colormap()

Gdk::Colormap::Colormap ( const Glib::RefPtr< Visual > &  visual, bool  allocate  )

explicitprotected

Member Function Documentation

alloc_color()

bool Gdk::Colormap::alloc_color	(	Color &	color,
		bool	writeable = false,
		bool	best_match = true
	)

Allocates a single color from a colormap.

Parameters

color	The color to allocate. On return the pixel field will be filled in if allocation succeeds.
writeable	If true, the color is allocated writeable (their values can later be changed using gdk_color_change()). Writeable colors cannot be shared between applications.
best_match	If true, GDK will attempt to do matching against existing colors if the color cannot be allocated as requested.

Returns

true if the allocation succeeded.

alloc_colors()

int Gdk::Colormap::alloc_colors	(	ArrayHandle_Color &	colors,
		int	ncolors,
		bool	writeable,
		bool	best_match,
		Glib::ArrayHandle< bool > &	success
	)

create()

static Glib::RefPtr<Colormap> Gdk::Colormap::create ( const Glib::RefPtr< Visual > &  visual, bool  allocate  )

static

free_color()

void Gdk::Colormap::free_color

(

Color &

color

)

free_colors()

void Gdk::Colormap::free_colors	(	Color &	colors,
		int	ncolors
	)

get_screen() [1/2]

Glib::RefPtr<Screen> Gdk::Colormap::get_screen

(

)

Gets the screen for which this colormap was created.

Returns

The screen for which this colormap was created.

get_screen() [2/2]

Glib::RefPtr<const Screen> Gdk::Colormap::get_screen

(

)

const

Gets the screen for which this colormap was created.

Returns

The screen for which this colormap was created.

get_system()

static Glib::RefPtr<Colormap> Gdk::Colormap::get_system ( )

static

Gets the system's default colormap for the default screen. (See gdk_colormap_get_system_for_screen())

Returns

The default colormap.

get_type()

static GType Gdk::Colormap::get_type ( )

static

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

get_visual() [1/2]

Glib::RefPtr<Visual> Gdk::Colormap::get_visual

(

)

Returns the visual for which a given colormap was created.

Returns

The visual of the colormap.

get_visual() [2/2]

Glib::RefPtr<const Visual> Gdk::Colormap::get_visual

(

)

const

Returns the visual for which a given colormap was created.

Returns

The visual of the colormap.

gobj() [1/2]

GdkColormap* Gdk::Colormap::gobj ( )

inline

Provides access to the underlying C GObject.

Definition at line 105 of file colormap.h.

gobj() [2/2]

const GdkColormap* Gdk::Colormap::gobj ( ) const

inline

Provides access to the underlying C GObject.

Definition at line 108 of file colormap.h.

gobj_copy()

GdkColormap* Gdk::Colormap::gobj_copy

(

)

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

query_color()

void Gdk::Colormap::query_color	(	gulong	pixel,
		Color &	result
	)

Locates the RGB color in colormap corresponding to the given hardware pixel pixel. pixel must be a valid pixel in the colormap; it's a programmer error to call this function with a pixel which is not in the colormap. Hardware pixels are normally obtained from alloc_colors(), or from a Gdk::Image. (A Gdk::Image contains image data in hardware format, a Gdk::Pixbuf contains image data in a canonical 24-bit RGB format.)

This function is rarely useful; it's used for example to implement the eyedropper feature in Gtk::ColorSelection.

Parameters

pixel	Pixel value in hardware display format.
result	Gdk::Color with red, green, blue fields initialized.

Friends And Related Function Documentation

wrap()

Glib::RefPtr< Gdk::Colormap > wrap ( GdkColormap *  object, bool  take_copy = false  )

related

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.

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The documentation for this class was generated from the following file:

• colormap.h