XQueryColor(3X11) X11R5 XQueryColor(3X11)NAME
XQueryColor, XQueryColors, XLookupColor, XParseColor - obtain color
values
SYNTAX
XQueryColor(display, colormap, def_in_out)
Display *display;
Colormap colormap;
XColor *def_in_out;
XQueryColors(display, colormap, defs_in_out, ncolors)
Display *display;
Colormap colormap;
XColor defs_in_out[];
int ncolors;
Status XLookupColor(display, colormap, color_name, exact_def_return,
screen_def_return)
Display *display;
Colormap colormap;
char *color_name;
XColor *exact_def_return, *screen_def_return;
Status XParseColor(display, colormap, spec, exact_def_return)
Display *display;
Colormap colormap;
char *spec;
XColor *exact_def_return;
ARGUMENTS
colormap Specifies the colormap.
color_name
Specifies the color name string (for example, red) whose
color definition structure you want returned.
def_in_out
Specifies and returns the RGB values for the pixel specified
in the structure.
defs_in_out
Specifies and returns an array of color definition structures
for the pixel specified in the structure.
display Specifies the connection to the X server.
exact_def_return
Returns the exact RGB values.
ncolors Specifies the number of structures in the color definition
array.
screen_def_return
Returns the closest RGB values provided by the hardware.
spec Specifies the color name string; case is ignored.
exact_def_return
Returns the exact color value for later use and sets the and
flags.
DESCRIPTION
The function returns the current RGB value for the pixel in the struc‐
ture and sets the and flags. The function returns the RGB value for
each pixel in each structure, and sets the and flags in each structure.
and can generate and errors.
The function looks up the string name of a color with respect to the
screen associated with the specified colormap. It returns both the
exact color values and the closest values provided by the screen with
respect to the visual type of the specified colormap. If the color
name is not in the Host Portable Character Encoding the result is
implementation dependent. Use of uppercase or lowercase does not mat‐
ter. returns nonzero if the name is resolved, otherwise it returns
zero.
The function looks up the string name of a color with respect to the
screen associated with the specified colormap. It returns the exact
color value. If the color name is not in the Host Portable Character
Encoding the result is implementation dependent. Use of uppercase or
lowercase does not matter. returns nonzero if the name is resolved,
otherwise it returns zero.
and can generate error.
COLOR NAMES
An RGB Device specification is identified by the prefix "rgb:" and con‐
forms to the following syntax:
rgb:<red>/<green>/<blue>
<red>, <green>, <blue> := h | hh | hhh | hhhh
h := single hexadecimal digits (case insignificant)
Note that h indicates the value scaled in 4 bits, hh the value scaled
in 8 bits, hhh the value scaled in 12 bits, and hhhh the value scaled
in 16 bits, respectively.
For backward compatibility, an older syntax for RGB Device is sup‐
ported, but its continued use is not encouraged. The syntax is an ini‐
tial sharp sign character followed by a numeric specification, in one
of the following formats:
#RGB (4 bits each)
#RRGGBB (8 bits each)
#RRRGGGBBB (12 bits each)
#RRRRGGGGBBBB (16 bits each)
The R, G, and B represent single hexadecimal digits. When fewer than
16 bits each are specified, they represent the most-significant bits of
the value (unlike the "rgb:" syntax, in which values are scaled). For
example, #3a7 is the same as #3000a0007000.
An RGB intensity specification is identified by the prefix "rgbi:" and
conforms to the following syntax:
rgbi:<red>/<green>/<blue>
Note that red, green, and blue are floating point values between 0.0
and 1.0, inclusive. The input format for these values is an optional
sign, a string of numbers possibly containing a decimal point, and an
optional exponent field containing an E or e followed by a possibly
signed integer string.
The standard device-independent string specifications have the follow‐
ing syntax:
CIEXYZ:<X>/<Y>/<Z>
CIEuvY:<u>/<v>/<Y>
CIExyY:<x>/<y>/<Y>
CIELab:<L>/<a>/<b>
CIELuv:<L>/<u>/<v>
TekHVC:<H>/<V>/<C>
All of the values (C, H, V, X, Y, Z, a, b, u, v, y, x) are floating
point values. The syntax for these values is an optional '+' or '-'
sign, a string of digits possibly containing a decimal point, and an
optional exponent field consisting of an 'E' or 'e' followed by an
optional '+' or '-' followed by a string of digits.
DIAGNOSTICS
A value for a Colormap argument does not name a defined Colormap.
Some numeric value falls outside the range of values accepted by the
request.
Unless a specific range is specified for an argument, the
full range defined by the argument's type is accepted. Any
argument defined as a set of alternatives can generate this
error.
SEE ALSOXAllocColor(3X11), XCreateColormap(3X11), XStoreColors(3X11)
Xlib - C Language X Interface
XQueryColor(3X11)
