XQueryColor(3X11) — UNIX Programmer’s Manual

NAME

XQueryColor, XQueryColors, XLookupColor − 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;

ARGUMENTS

colormapSpecifies the colormap.

color_nameSpecifies the color name string (for example, red) whose color definition structure you want returned.

def_in_outSpecifies and returns the RGB values for the pixel specified in the structure.

defs_in_outSpecifies and returns an array of color definition structures for the pixel specified in the structure.

displaySpecifies the connection to the X server.

exact_def_return
Returns the exact RGB values.

ncolorsSpecifies the number of XColor structures in the color definition array.

screen_def_return
Returns the closest RGB values provided by the hardware.

DESCRIPTION

The XQueryColor function returns the RGB values for each pixel in the XColor structures and sets the DoRed, DoGreen, and DoBlue flags. The XQueryColors function returns the RGB values for each pixel in the XColor structures and sets the DoRed, DoGreen, and DoBlue flags. .PN XQueryColor and .PN 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. You should use the ISO Latin-1 encoding; uppercase and lowercase do not matter. XLookupColor returns nonzero if the name existed in the color database or zero if it did not exist.

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.

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