Index for Section 3X11

Alphabetical listing for X

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XQueryColor(3X11)
X11R6
NAME
  XQueryColor, XQueryColors, XLookupColor, XParseColor - obtain color values

SYNOPSIS
  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 XColor 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 DoRed,
      DoGreen, and DoBlue flags.

DESCRIPTION
  The XQueryColor function returns the current RGB value for the pixel in the
  XColor structure and sets the DoRed, DoGreen, and DoBlue flags. The
  XQueryColors function returns the RGB value for each pixel in each XColor
  structure and sets the DoRed, DoGreen, and DoBlue flags in each structure.

  XQueryColor and XQueryColors can generate BadColor and BadValue errors.

  The XLookupColor 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 matter.  XLookupColor
  returns nonzero if the name is resolved; otherwise, it returns zero.

  The XParseColor 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.  XParseColor returns nonzero if the name is
  resolved; otherwise, it returns zero.

  XLookupColor and XParseColor can generate BadColor error.

COLOR NAMES
  An RGB Device specification is identified by the prefix "rgb:" and conforms
  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 supported,
  but its continued use is not encouraged. The syntax is an initial 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,
  the string "#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 following
  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 plus or minus 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 plus or
  minus followed by a string of digits.

DIAGNOSTICS
  BadColor
	  A value for a Colormap argument does not name a defined Colormap.

  BadValue
	  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 ALSO
  XAllocColor(3X11), XCreateColormap(3X11), XStoreColors(3X11)

  Xlib -- C Language X Interface

Index for Section 3X11

Alphabetical listing for X

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