Function xcb::xproto::query_text_extents [−][src]
pub fn query_text_extents<'a>(
c: &'a Connection,
font: Fontable,
string: &[Char2b]
) -> QueryTextExtentsCookie<'a>
get text extents
Query text extents from the X11 server. This request returns the bounding 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 characters 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 metrics 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 preceding 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 character plus W. The lbearing member is set
to the minimum L of all characters in the string. The rbearing member is set to
the maximum R.
For fonts defined with linear indexing rather than 2-byte matrix indexing, 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 zero metrics.
Characters with all zero metrics are ignored. If the font has no defined default_char, the undefined characters in the string are also ignored.
parameters:
-
c: The connection object to the server
-
font: The
font
to calculate text extents in. You can also pass a graphics context. -
string: The text to get text extents for.