gnu/dist/gettext/gettext-tools/lib/linebreak.h

   1 /* linebreak.h - line breaking of Unicode strings
   2    Copyright (C) 2001-2003 Free Software Foundation, Inc.
   3    Written by Bruno Haible <haible@clisp.cons.org>, 2001.
   4
   5 This program is free software; you can redistribute it and/or modify
   6 it under the terms of the GNU General Public License as published by
   7 the Free Software Foundation; either version 2, or (at your option)
   8 any later version.
   9
  10 This program is distributed in the hope that it will be useful,
  11 but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  13 GNU General Public License for more details.
  14
  15 You should have received a copy of the GNU General Public License
  16 along with this program; if not, write to the Free Software
  17 Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */
  18
  19 #ifndef _LINEBREAK_H
  20 #define _LINEBREAK_H
  21
  22 /* Get size_t.  */
  23 #include <stddef.h>
  24
  25
  26 /* Display width.  */
  27
  28 /* These functions are locale dependent.  The encoding argument identifies
  29    the encoding (e.g. "ISO-8859-2" for Polish).  */
  30
  31 /* Return the encoding of the current locale.  */
  32 extern const char * locale_charset (void);
  33
  34 /* Determine number of column positions required for UC. */
  35 extern int uc_width (unsigned int uc, const char *encoding);
  36
  37 /* Determine number of column positions required for first N units
  38    (or fewer if S ends before this) in S.  */
  39 extern int u8_width (const unsigned char *s, size_t n, const char *encoding);
  40 extern int u16_width (const unsigned short *s, size_t n, const char *encoding);
  41 extern int u32_width (const unsigned int *s, size_t n, const char *encoding);
  42
  43
  44 /* Line breaking.  */
  45
  46 enum {
  47   UC_BREAK_UNDEFINED,
  48   UC_BREAK_PROHIBITED,
  49   UC_BREAK_POSSIBLE,
  50   UC_BREAK_MANDATORY,
  51   UC_BREAK_HYPHENATION
  52 };
  53
  54 /* Determine the line break points in S, and store the result at p[0..n-1].
  55    p[i] = UC_BREAK_MANDATORY means that s[i] is a line break character.
  56    p[i] = UC_BREAK_POSSIBLE means that a line break may be inserted between
  57           s[i-1] and s[i].
  58    p[i] = UC_BREAK_HYPHENATION means that a hyphen and a line break may be
  59           inserted between s[i-1] and s[i].  But beware of language dependent
  60           hyphenation rules.
  61    p[i] = UC_BREAK_PROHIBITED means that s[i-1] and s[i] must not be separated.
  62  */
  63 extern void u8_possible_linebreaks (const unsigned char *s, size_t n,
  64                                     const char *encoding,
  65                                     char *p);
  66 extern void u16_possible_linebreaks (const unsigned short *s, size_t n,
  67                                      const char *encoding,
  68                                      char *p);
  69 extern void u32_possible_linebreaks (const unsigned int *s, size_t n,
  70                                      const char *encoding,
  71                                      char *p);
  72 extern void mbs_possible_linebreaks (const char *s, size_t n,
  73                                      const char *encoding,
  74                                      char *p);
  75
  76 /* Choose the best line breaks, assuming the uc_width function.
  77    Return the column after the end of the string.
  78    o is an optional override; if o[i] != UC_BREAK_UNDEFINED, o[i] takes
  79    precedence over p[i] as returned by the *_possible_linebreaks function.
  80  */
  81 extern int
  82        u8_width_linebreaks (const unsigned char *s, size_t n,
  83                             int width, int start_column, int at_end_columns,
  84                             const char *o, const char *encoding,
  85                             char *p);
  86 extern int
  87        u16_width_linebreaks (const unsigned short *s, size_t n,
  88                              int width, int start_column, int at_end_columns,
  89                              const char *o, const char *encoding,
  90                              char *p);
  91 extern int
  92        u32_width_linebreaks (const unsigned int *s, size_t n,
  93                              int width, int start_column, int at_end_columns,
  94                              const char *o, const char *encoding,
  95                              char *p);
  96 extern int
  97        mbs_width_linebreaks (const char *s, size_t n,
  98                              int width, int start_column, int at_end_columns,
  99                              const char *o, const char *encoding,
 100                              char *p);
 101
 102
 103 #endif /* _LINEBREAK_H */