gdk-Colormaps-and-Colors: Colormaps and Colors
Description
Manipulation of colors and colormapsMethods and Functions
gdkColormapNew(visual, allocate)
gdkColormapGetSystem()
gdkColormapGetSystemSize()
gdkColormapAllocColors(colormap, colors, writeable, best.match)
gdkColormapAllocColor(object, color, writeable, best.match)
gdkColormapFreeColors(object, colors)
gdkColormapQueryColor(object, pixel)
gdkColormapGetVisual(object)
gdkColormapGetScreen(object)
gdkColorsStore(object, colors)
gdkColorWhite(object)
gdkColorBlack(object)
gdkColorParse(spec)
gdkColorAlloc(object, color)
gdkColorChange(object, color)
gdkColorToString(object)
gdkColormap(visual, allocate)Detailed Description
These functions are used to modify colormaps.
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 gdkColormapGetSystem) 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
gdkRgbGetColormap. However, when using GdkRGB,
it is not generally necessary to allocate colors
directly. In previous revisions of this interface, a number
of functions that take a GdkColormap parameter
were replaced with functions whose names began
with "gdk_colormap_". This process will probably
be extended somewhat in the future -
gdkColorWhite, gdkColorBlack, and
gdkColorChange will probably become aliases.Structures
GdkColor-
The
GdkColor structure is used to describe an
allocated or unallocated color.
GdkColor is a transparent-type.
pixel- [numeric] For allocated colors, the value used to
draw this color on the screen.
red- [integer] The red component of the color. This is
a value between 0 and 65535, with 65535 indicating
full intensitiy.
green- [integer] The blue component of the color.
blue- [integer] The green component of the color.
GdkColormap-
The colormap structure contains the following public fields.
size- For pseudo-color colormaps, the number of colors
in the colormap.
colors- An list containing the current values in the
colormap. This can be used to map from pixel values
back to RGB values. This is only meaningful for
pseudo-color colormaps.
Convenient Construction
gdkColormap is the equivalent of gdkColormapNew.