Function x11rb::protocol::xproto::query_text_extents

source · 
pub fn query_text_extents<'c, 'input, Conn>(
    conn: &'c Conn,
    font: Fontable,
    string: &'input [Char2b]
) -> Result<Cookie<'c, Conn, QueryTextExtentsReply>, ConnectionError>
where
    Conn: RequestConnection + ?Sized,
Expand description

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.

Fields

  • 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.

Errors

  • GContext - The specified graphics context does not exist.
  • Font - The specified font does not exist.