Manpages - XcmsAllocColor.3

XcmsAllocColor, XcmsAllocNamedColor - allocate colors

Status XcmsAllocColor ( Display */display/ , Colormap colormap , XcmsColor */color_in_out/ , XcmsColorFormat result_format );

Status XcmsAllocNamedColor ( Display */display/ , Colormap colormap , _Xconst char */color_string/ , XcmsColor */color_screen_return/ , XcmsColor */color_exact_return/ , XcmsColorFormat result_format );

display

Specifies the connection to the X server.

colormap

Specifies the colormap.

color_exact_return

Returns the color specification parsed from the color string or parsed from the corresponding string found in a color-name database.

color_in_out

Specifies the color to allocate and returns the pixel and color that is actually used in the colormap.

color_screen_return

Returns the pixel value of the color cell and color specification that actually is stored for that cell. Specifies the color string whose color definition structure is to be returned.

result_format

Specifies the color format for the returned color specification.

The XcmsAllocColor function is similar to XAllocColor except the color can be specified in any format. The XcmsAllocColor function ultimately calls XAllocColor to allocate a read-only color cell (colormap entry) with the specified color. XcmsAllocColor first converts the color specified to an RGB value and then passes this to XAllocColor. XcmsAllocColor returns the pixel value of the color cell and the color specification actually allocated. This returned color specification is the result of converting the RGB value returned by XAllocColor into the format specified with the result_format argument. If there is no interest in a returned color specification, unnecessary computation can be bypassed if result_format is set to XcmsRGBFormat. The corresponding colormap cell is read-only. If this routine returns XcmsFailure, the color_in_out color specification is left unchanged.

XcmsAllocColor can generate a BadColor errors.

The XcmsAllocNamedColor function is similar to XAllocNamedColor except that the color returned can be in any format specified. This function ultimately calls XAllocColor to allocate a read-only color cell with the color specified by a color string. The color string is parsed into an XcmsColor structure (see XcmsLookupColor), converted to an RGB value, and finally passed to XAllocColor. 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.

This function returns both the color specification as a result of parsing (exact specification) and the actual color specification stored (screen specification). This screen specification is the result of converting the RGB value returned by XAllocColor into the format specified in result_format. If there is no interest in a returned color specification, unnecessary computation can be bypassed if result_format is set to XcmsRGBFormat. If color_screen_return and color_exact_return point to the same structure, the pixel field will be set correctly, but the color values are undefined.

XcmsAllocNamedColor can generate a BadColor errors.

BadColor

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

XcmsQueryColor(3), XcmsStoreColor(3)
Xlib - C Language X Interface