xcb_query_text_extents(3) XCB Requests xcb_query_text_extents(3)NAME
xcb_query_text_extents - get text extents
SYNOPSIS
#include <xcb/xproto.h>
Request function
xcb_query_text_extents_cookie_t
xcb_query_text_extents(xcb_connection_t *conn,
xcb_fontable_t font, uint32_t string_len, const
xcb_char2b_t *string);
Reply datastructure
typedef struct xcb_query_text_extents_reply_t {
uint8_t response_type;
uint8_t draw_direction;
uint16_t sequence;
uint32_t length;
int16_t font_ascent;
int16_t font_descent;
int16_t overall_ascent;
int16_t overall_descent;
int32_t overall_width;
int32_t overall_left;
int32_t overall_right;
} xcb_query_text_extents_reply_t;
Reply function
xcb_query_text_extents_reply_t
*xcb_query_text_extents_reply(xcb_connection_t *conn,
xcb_query_text_extents_cookie_t cookie,
xcb_generic_error_t **e);
REQUEST ARGUMENTS
conn The XCB connection to X11.
font The font to calculate text extents in. You can also pass a
graphics context.
string_len
The number of characters in string.
string The text to get text extents for.
REPLY FIELDS
response_type
The type of this reply, in this case XCB_QUERY_TEXT_EXTENTS.
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).
draw_direction
One of the following values:
XCB_FONT_DRAW_LEFT_TO_RIGHT
TODO: NOT YET DOCUMENTED.
XCB_FONT_DRAW_RIGHT_TO_LEFT
TODO: NOT YET DOCUMENTED.
TODO: NOT YET DOCUMENTED.
font_ascent
TODO: NOT YET DOCUMENTED.
font_descent
TODO: NOT YET DOCUMENTED.
overall_ascent
TODO: NOT YET DOCUMENTED.
overall_descent
TODO: NOT YET DOCUMENTED.
overall_width
TODO: NOT YET DOCUMENTED.
overall_left
TODO: NOT YET DOCUMENTED.
overall_right
TODO: NOT YET DOCUMENTED.
DESCRIPTION
Query text extents from the X11 server. This request returns the bound‐
ing box of the specified 16-bit character string in the specified font
or the font contained in the specified graphics context.
font_ascent is set to the maximum of the ascent metrics of all charac‐
ters in the string. font_descent is set to the maximum of the descent
metrics. overall_width is set to the sum of the character-width met‐
rics of all characters in the string. For each character in the string,
let W be the sum of the character-width metrics of all characters pre‐
ceding it in the string. Let L be the left-side-bearing metric of the
character plus W. Let R be the right-side-bearing metric of the charac‐
ter plus W. The lbearing member is set to the minimum L of all charac‐
ters in the string. The rbearing member is set to the maximum R.
For fonts defined with linear indexing rather than 2-byte matrix index‐
ing, each xcb_char2b_t structure is interpreted as a 16-bit number with
byte1 as the most significant byte. If the font has no defined default
character, undefined characters in the string are taken to have all ze‐
ro metrics.
Characters with all zero metrics are ignored. If the font has no de‐
fined default_char, the undefined characters in the string are also ig‐
nored.
RETURN VALUE
Returns an xcb_query_text_extents_cookie_t. Errors have to be handled
when calling the reply function xcb_query_text_extents_reply.
If you want to handle errors in the event loop instead, use
xcb_query_text_extents_unchecked. See xcb-requests(3) for details.
ERRORS
xcb_font_error_t
The specified font does not exist.
xcb_gc_error_t
The specified graphics context does not exist.
SEE ALSOxcb-requests(3)AUTHOR
Generated from xproto.xml. Contact xcb@lists.freedesktop.org for cor‐
rections and improvements.
XCB 2013-07-27 xcb_query_text_extents(3)
