xcb_alloc_color man page

xcb_alloc_color — Allocate a color

Synopsis

#include <xcb/xproto.h>

Request function

xcb_alloc_color_cookie_t xcb_alloc_color(xcb_connection_t *conn, xcb_colormap_t cmap, uint16_t red, uint16_t green, uint16_t blue);

Reply datastructure

typedef struct xcb_alloc_color_reply_t {
    uint8_t  response_type;
    uint8_t  pad0;
    uint16_t sequence;
    uint32_t length;
    uint16_t red;
    uint16_t green;
    uint16_t blue;
    uint8_t  pad1[2];
    uint32_t pixel;
} xcb_alloc_color_reply_t;

Reply function

xcb_alloc_color_reply_t *xcb_alloc_color_reply(xcb_connection_t *conn, xcb_alloc_color_cookie_t cookie, xcb_generic_error_t **e);

Request Arguments

conn
The XCB connection to X11.
cmap
TODO
red
The red value of your color.
green
The green value of your color.
blue
The blue value of your color.

Reply Fields

response_type
The type of this reply, in this case XCB_ALLOC_COLOR. This field is also present in the xcb_generic_reply_t and can be used to tell replies apart from each other.
sequence
The sequence number of the last request processed by the X11 server.
length
The length of the reply, in words (a word is 4 bytes).
red
TODO: NOT YET DOCUMENTED.
green
TODO: NOT YET DOCUMENTED.
blue
TODO: NOT YET DOCUMENTED.
pixel
TODO: NOT YET DOCUMENTED.

Description

Allocates a read-only colormap entry corresponding to the closest RGB value supported by the hardware. If you are using TrueColor, you can take a shortcut and directly calculate the color pixel value to avoid the round trip. But, for example, on 16-bit color setups (VNC), you can easily get the closest supported RGB value to the RGB value you are specifying.

Return Value

Returns an xcb_alloc_color_cookie_t. Errors have to be handled when calling the reply function xcb_alloc_color_reply.

If you want to handle errors in the event loop instead, use xcb_alloc_color_unchecked. See xcb-requests(3) for details.

Errors

xcb_colormap_error_t
The specified colormap cmap does not exist.

See Also

xcb-requests(3)

Author

Generated from xproto.xml. Contact xcb@lists.freedesktop.org for corrections and improvements.

Referenced By

xcb_alloc_color_reply(3) and xcb_alloc_color_unchecked(3) are aliases of xcb_alloc_color(3).

libxcb 1.12 X Version 11 XCB Requests