code.delx.au - gnu-emacs/blob - src/composite.h

   1 /* Header for composite sequence handler.
   2    Copyright (C) 2001, 2002, 2003, 2004, 2005,
   3                  2006 Free Software Foundation, Inc.
   4    Copyright (C) 1997
   5      National Institute of Advanced Industrial Science and Technology (AIST)
   6      Registration Number H14PRO021
   7
   8 This file is part of GNU Emacs.
   9
  10 GNU Emacs is free software; you can redistribute it and/or modify
  11 it under the terms of the GNU General Public License as published by
  12 the Free Software Foundation; either version 2, or (at your option)
  13 any later version.
  14
  15 GNU Emacs is distributed in the hope that it will be useful,
  16 but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 GNU General Public License for more details.
  19
  20 You should have received a copy of the GNU General Public License
  21 along with GNU Emacs; see the file COPYING.  If not, write to
  22 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  23 Boston, MA 02110-1301, USA.  */
  24
  25 #ifndef EMACS_COMPOSITE_H
  26 #define EMACS_COMPOSITE_H
  27
  28 /* Methods to display a sequence of components a composition.  */
  29 enum composition_method {
  30   /* The first two are actually not methods, but used in code
  31      conversion to specify the current composing status.  */
  32   COMPOSITION_DISABLED,         /* Never handle composition data */
  33   COMPOSITION_NO,               /* Not processing composition data */
  34   /* Compose relatively without alternate characters.  */
  35   COMPOSITION_RELATIVE,
  36   /* Compose by specified composition rule.  This is not used in Emacs
  37      21 but we need it to decode files saved in the older versions of
  38      Emacs.  */
  39   COMPOSITION_WITH_RULE,
  40   /* Compose relatively with alternate characters.  */
  41   COMPOSITION_WITH_ALTCHARS,
  42   /* Compose by specified composition rule with alternate characters.  */
  43   COMPOSITION_WITH_RULE_ALTCHARS
  44 };
  45
  46 /* Maximum number of compoments a single composition can have.  */
  47 #define MAX_COMPOSITION_COMPONENTS 16
  48
  49 /* These macros access information about a composition that
  50    has `composition' property PROP.  PROP is:
  51         ((LENGTH . COMPONENTS) . MODIFICATION-FUNC)
  52    or
  53         (COMPOSITION-ID . (LENGTH COMPONENTS . MODIFICATION-FUNC))
  54    They don't check validity of PROP.  */
  55
  56 /* Temporary variable used only in the following macros.  */
  57 extern Lisp_Object composition_temp;
  58
  59 /* Return 1 iff the composition is already registered.  */
  60 #define COMPOSITION_REGISTERD_P(prop) INTEGERP (XCAR (prop))
  61
  62 /* Return ID number of the already registered composition.  */
  63 #define COMPOSITION_ID(prop) XINT (XCAR (prop))
  64
  65 /* Return length of the composition.  */
  66 #define COMPOSITION_LENGTH(prop)        \
  67   (COMPOSITION_REGISTERD_P (prop)       \
  68    ? XINT (XCAR (XCDR (prop)))          \
  69    : XINT (XCAR (XCAR (prop))))
  70
  71 /* Return components of the composition.  */
  72 #define COMPOSITION_COMPONENTS(prop)    \
  73   (COMPOSITION_REGISTERD_P (prop)       \
  74    ? XCAR (XCDR (XCDR (prop)))          \
  75    : XCDR (XCAR (prop)))
  76
  77 /* Return modification function of the composition.  */
  78 #define COMPOSITION_MODIFICATION_FUNC(prop)     \
  79   (COMPOSITION_REGISTERD_P (prop)               \
  80    ? XCDR (XCDR (XCDR (prop)))                  \
  81    : CONSP (prop) ? XCDR (prop) : Qnil)
  82
  83 /* Return the method of composition.  */
  84 #define COMPOSITION_METHOD(prop)                                        \
  85   (COMPOSITION_REGISTERD_P (prop)                                       \
  86    ? composition_table[COMPOSITION_ID (prop)]->method                   \
  87    : (composition_temp = XCDR (XCAR (prop)),                            \
  88       (NILP (composition_temp)                                          \
  89        ? COMPOSITION_RELATIVE                                           \
  90        : ((INTEGERP (composition_temp) || STRINGP (composition_temp))   \
  91           ? COMPOSITION_WITH_ALTCHARS                                   \
  92           : COMPOSITION_WITH_RULE_ALTCHARS))))
  93
  94 /* Return 1 iff the composition is valid.  It is valid if length of
  95    the composition equals to (END - START).  */
  96 #define COMPOSITION_VALID_P(start, end, prop)                   \
  97   (CONSP (prop)                                                 \
  98    && (COMPOSITION_REGISTERD_P (prop)                           \
  99        ? (COMPOSITION_ID (prop) >= 0                            \
 100           && COMPOSITION_ID (prop) <= n_compositions            \
 101           && CONSP (XCDR (prop)))                               \
 102        : (composition_temp = XCAR (prop),                       \
 103           (CONSP (composition_temp)                             \
 104            && (composition_temp = XCDR (composition_temp),      \
 105                (NILP (composition_temp)                         \
 106                 || STRINGP (composition_temp)                   \
 107                 || VECTORP (composition_temp)                   \
 108                 || INTEGERP (composition_temp)                  \
 109                 || CONSP (composition_temp))))))                \
 110    && (end - start) == COMPOSITION_LENGTH (prop))
 111
 112 /* Return the Nth glyph of composition specified by CMP.  CMP is a
 113    pointer to `struct composition'. */
 114 #define COMPOSITION_GLYPH(cmp, n)                                       \
 115   XINT (XVECTOR (XVECTOR (XHASH_TABLE (composition_hash_table)          \
 116                           ->key_and_value)                              \
 117                  ->contents[cmp->hash_index * 2])                       \
 118         ->contents[cmp->method == COMPOSITION_WITH_RULE_ALTCHARS        \
 119                   ? (n) * 2 : (n)])
 120
 121 /* Return the encoded composition rule to compose the Nth glyph of
 122    rule-base composition specified by CMP.  CMP is a pointer to
 123    `struct composition'. */
 124 #define COMPOSITION_RULE(cmp, n)                                \
 125   XINT (XVECTOR (XVECTOR (XHASH_TABLE (composition_hash_table)  \
 126                           ->key_and_value)                      \
 127                  ->contents[cmp->hash_index * 2])               \
 128         ->contents[(n) * 2 - 1])
 129
 130 /* Decode encoded composition rule RULE_CODE into GREF (global
 131    reference point code) and NREF (new reference point code).  Don't
 132    check RULE_CODE, always set GREF and NREF to valid values.  */
 133 #define COMPOSITION_DECODE_RULE(rule_code, gref, nref)  \
 134   do {                                                  \
 135     gref = (rule_code) / 12;                            \
 136     if (gref > 12) gref = 11;                           \
 137     nref = (rule_code) % 12;                            \
 138   } while (0)
 139
 140 /* Return encoded composition rule for the pair of global reference
 141    point GREF and new reference point NREF.  If arguments are invalid,
 142    return -1. */
 143 #define COMPOSITION_ENCODE_RULE(gref, nref)             \
 144   ((unsigned) (gref) < 12 && (unsigned) (nref) < 12     \
 145    ? (gref) * 12 + (nref) : -1)
 146
 147 /* Data structure that records information about a composition
 148    currently used in some buffers or strings.
 149
 150    When a composition is assigned an ID number (by
 151    get_composition_id), this structure is allocated for the
 152    composition and linked in composition_table[ID].
 153
 154    Identical compositions appearing at different places have the same
 155    ID, and thus share the same instance of this structure.  */
 156
 157 struct composition {
 158   /* Number of glyphs of the composition components.  */
 159   unsigned glyph_len;
 160
 161   /* Width, ascent, and descent pixels of the composition.  */
 162   short pixel_width, ascent, descent;
 163
 164   /* How many columns the overall glyphs occupy on the screen.  This
 165      gives an approximate value for column calculation in
 166      Fcurrent_column, and etc.  */
 167   unsigned short width;
 168
 169   /* Method of the composition.  */
 170   enum composition_method method;
 171
 172   /* Index to the composition hash table.  */
 173   int hash_index;
 174
 175   /* For which font we have calculated the remaining members.  The
 176      actual type is device dependent.  */
 177   void *font;
 178
 179   /* Pointer to an array of x-offset and y-offset (by pixels) of
 180      glyphs.  This points to a sufficient memory space (sizeof (int) *
 181      glyph_len * 2) that is allocated when the composition is
 182      registered in composition_table.  X-offset and Y-offset of Nth
 183      glyph are (2N)th and (2N+1)th elements respectively.  */
 184   short *offsets;
 185 };
 186
 187 /* Table of pointers to the structure `composition' indexed by
 188    COMPOSITION-ID.  */
 189 extern struct composition **composition_table;
 190 /* Number of the currently registered compositions.  */
 191 extern int n_compositions;
 192
 193 /* Mask bits for CHECK_MASK arg to update_compositions.
 194    For a change in the region FROM and TO, check compositions ... */
 195 #define CHECK_HEAD      1       /* adjacent to FROM */
 196 #define CHECK_TAIL      2       /* adjacent to TO */
 197 #define CHECK_INSIDE    4       /* between FROM and TO */
 198 #define CHECK_BORDER    (CHECK_HEAD | CHECK_TAIL)
 199 #define CHECK_ALL       (CHECK_BORDER | CHECK_INSIDE)
 200
 201 extern Lisp_Object Qcomposition;
 202 extern Lisp_Object composition_hash_table;
 203
 204 extern int get_composition_id P_ ((int, int, int, Lisp_Object, Lisp_Object));
 205 extern int find_composition P_ ((int, int, int *, int *, Lisp_Object *,
 206                                  Lisp_Object));
 207 extern void update_compositions P_ ((int, int, int));
 208 extern void make_composition_value_copy P_ ((Lisp_Object));
 209 extern void compose_region P_ ((int, int, Lisp_Object, Lisp_Object,
 210                                 Lisp_Object));
 211 extern void syms_of_composite P_ ((void));
 212 extern void compose_text P_ ((int, int, Lisp_Object, Lisp_Object,
 213                               Lisp_Object));
 214
 215 #endif /* not EMACS_COMPOSITE_H */
 216
 217 /* arch-tag: 59524d89-c645-47bd-b5e6-65e861690118
 218    (do not change this comment) */