src/composite.h

   1 /* Header for composite sequence handler.
   2    Copyright (C) 1999 Electrotechnical Laboratory, JAPAN.
   3    Licensed to the Free Software Foundation.
   4    Copyright (C) 2001 Free Software Foundation, Inc.
   5    Copyright (C) 2001, 2002
   6      National Institute of Advanced Industrial Science and Technology (AIST)
   7      Registration Number H13PRO009
   8
   9 This file is part of GNU Emacs.
  10
  11 GNU Emacs is free software; you can redistribute it and/or modify
  12 it under the terms of the GNU General Public License as published by
  13 the Free Software Foundation; either version 2, or (at your option)
  14 any later version.
  15
  16 GNU Emacs is distributed in the hope that it will be useful,
  17 but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 GNU General Public License for more details.
  20
  21 You should have received a copy of the GNU General Public License
  22 along with GNU Emacs; see the file COPYING.  If not, write to
  23 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  24 Boston, MA 02111-1307, USA.  */
  25
  26 #ifndef EMACS_COMPOSITE_H
  27 #define EMACS_COMPOSITE_H
  28
  29 /* Methods to display a sequence of components a composition.  */
  30 enum composition_method {
  31   /* Compose relatively without alternate characters.  */
  32   COMPOSITION_RELATIVE,
  33   /* Compose by specified composition rules.  This is not used in
  34      Emacs 21 but we need it to decode files saved in the older
  35      versions of Emacs.  */
  36   COMPOSITION_WITH_RULE,
  37   /* Compose relatively with alternate characters.  */
  38   COMPOSITION_WITH_ALTCHARS,
  39   /* Compose by specified composition rules with alternate characters.  */
  40   COMPOSITION_WITH_RULE_ALTCHARS,
  41   /* This is not a method.  */
  42   COMPOSITION_NO
  43 };
  44
  45 /* Maximum number of compoments a single composition can have.  */
  46 #define MAX_COMPOSITION_COMPONENTS 16
  47
  48 /* These macros access information about a composition that
  49    has `composition' property PROP.  PROP is:
  50         ((LENGTH . COMPONENTS) . MODIFICATION-FUNC)
  51    or
  52         (COMPOSITION-ID . (LENGTH COMPONENTS . MODIFICATION-FUNC))
  53    They don't check validity of PROP.  */
  54
  55 /* Temporary variable used only in the following macros.  */
  56 extern Lisp_Object composition_temp;
  57
  58 /* Return 1 iff the composition is already registered.  */
  59 #define COMPOSITION_REGISTERD_P(prop) INTEGERP (XCAR (prop))
  60
  61 /* Return ID number of the already registered composition.  */
  62 #define COMPOSITION_ID(prop) XINT (XCAR (prop))
  63
  64 /* Return length of the composition.  */
  65 #define COMPOSITION_LENGTH(prop)        \
  66   (COMPOSITION_REGISTERD_P (prop)       \
  67    ? XINT (XCAR (XCDR (prop)))          \
  68    : XINT (XCAR (XCAR (prop))))
  69
  70 /* Return components of the composition.  */
  71 #define COMPOSITION_COMPONENTS(prop)    \
  72   (COMPOSITION_REGISTERD_P (prop)       \
  73    ? XCAR (XCDR (XCDR (prop)))          \
  74    : XCDR (XCAR (prop)))
  75
  76 /* Return modification function of the composition.  */
  77 #define COMPOSITION_MODIFICATION_FUNC(prop)     \
  78   (COMPOSITION_REGISTERD_P (prop)               \
  79    ? XCDR (XCDR (XCDR (prop)))                  \
  80    : XCDR (prop))
  81
  82 /* Return the method of composition.  */
  83 #define COMPOSITION_METHOD(prop)                                        \
  84   (COMPOSITION_REGISTERD_P (prop)                                       \
  85    ? composition_table[COMPOSITION_ID (prop)]->method                   \
  86    : (composition_temp = XCDR (XCAR (prop)),                            \
  87       (NILP (composition_temp)                                          \
  88        ? COMPOSITION_RELATIVE                                           \
  89        : ((INTEGERP (composition_temp) || STRINGP (composition_temp))   \
  90           ? COMPOSITION_WITH_ALTCHARS                                   \
  91           : COMPOSITION_WITH_RULE_ALTCHARS))))
  92
  93 /* Return 1 iff the composition is valid.  It is valid if length of
  94    the composition equals to (END - START).  */
  95 #define COMPOSITION_VALID_P(start, end, prop)                   \
  96   (CONSP (prop)                                                 \
  97    && (COMPOSITION_REGISTERD_P (prop)                           \
  98        ? (COMPOSITION_ID (prop) >= 0                            \
  99           && COMPOSITION_ID (prop) <= n_compositions            \
 100           && CONSP (XCDR (prop)))                               \
 101        : (composition_temp = XCAR (prop),                       \
 102           (CONSP (composition_temp)                             \
 103            && (composition_temp = XCDR (composition_temp),      \
 104                (NILP (composition_temp)                         \
 105                 || STRINGP (composition_temp)                   \
 106                 || VECTORP (composition_temp)                   \
 107                 || INTEGERP (composition_temp)                  \
 108                 || CONSP (composition_temp))))))                \
 109    && (end - start) == COMPOSITION_LENGTH (prop))
 110
 111 /* Return the Nth glyph of composition specified by CMP.  CMP is a
 112    pointer to `struct composition'. */
 113 #define COMPOSITION_GLYPH(cmp, n)                                       \
 114   XINT (XVECTOR (XVECTOR (XHASH_TABLE (composition_hash_table)          \
 115                           ->key_and_value)                              \
 116                  ->contents[cmp->hash_index * 2])                       \
 117         ->contents[cmp->method == COMPOSITION_WITH_RULE_ALTCHARS        \
 118                   ? (n) * 2 : (n)])
 119
 120 /* Return the encoded composition rule to compose the Nth glyph of
 121    rule-base composition specified by CMP.  CMP is a pointer to
 122    `struct composition'. */
 123 #define COMPOSITION_RULE(cmp, n)                                \
 124   XINT (XVECTOR (XVECTOR (XHASH_TABLE (composition_hash_table)  \
 125                           ->key_and_value)                      \
 126                  ->contents[cmp->hash_index * 2])               \
 127         ->contents[(n) * 2 - 1])
 128
 129 /* Decode encoded composition rule RULE_CODE into GREF (global
 130    reference point code) and NREF (new reference point code).  Don't
 131    check RULE_CODE, always set GREF and NREF to valid values.  */
 132 #define COMPOSITION_DECODE_RULE(rule_code, gref, nref)  \
 133   do {                                                  \
 134     gref = (rule_code) / 12;                            \
 135     if (gref > 12) gref = 11;                           \
 136     nref = (rule_code) % 12;                            \
 137   } while (0)
 138
 139 /* Return encoded composition rule for the pair of global reference
 140    point GREF and new reference point NREF.  If arguments are invalid,
 141    return -1. */
 142 #define COMPOSITION_ENCODE_RULE(gref, nref)             \
 143   ((unsigned) (gref) < 12 && (unsigned) (nref) < 12     \
 144    ? (gref) * 12 + (nref) : -1)
 145
 146 /* Data structure that records information about a composition
 147    currently used in some buffers or strings.
 148
 149    When a composition is assigned an ID number (by
 150    get_composition_id), this structure is allocated for the
 151    composition and linked in composition_table[ID].
 152
 153    Identical compositions appearing at different places have the same
 154    ID, and thus share the same instance of this structure.  */
 155
 156 struct composition {
 157   /* Number of glyphs of the composition components.  */
 158   unsigned glyph_len;
 159
 160   /* Width, ascent, and descent pixels of the composition.  */
 161   short pixel_width, ascent, descent;
 162
 163   /* How many columns the overall glyphs occupy on the screen.  This
 164      gives an approximate value for column calculation in
 165      Fcurrent_column, and etc.  */
 166   unsigned short width;
 167
 168   /* Method of the composition.  */
 169   enum composition_method method;
 170
 171   /* Index to the composition hash table.  */
 172   int hash_index;
 173
 174   /* For which font we have calculated the remaining members.  The
 175      actual type is device dependent.  */
 176   void *font;
 177
 178   /* Pointer to an array of x-offset and y-offset (by pixels) of
 179      glyphs.  This points to a sufficient memory space (sizeof (int) *
 180      glyph_len * 2) that is allocated when the composition is
 181      registered in composition_table.  X-offset and Y-offset of Nth
 182      glyph are (2N)th and (2N+1)th elements respectively.  */
 183   short *offsets;
 184 };
 185
 186 /* Table of pointers to the structure `composition' indexed by
 187    COMPOSITION-ID.  */
 188 extern struct composition **composition_table;
 189 /* Number of the currently registered compositions.  */
 190 extern int n_compositions;
 191
 192 /* Mask bits for CHECK_MASK arg to update_compositions.
 193    For a change in the region FROM and TO, check compositions ... */
 194 #define CHECK_HEAD      1       /* adjacent to FROM */
 195 #define CHECK_TAIL      2       /* adjacent to TO */
 196 #define CHECK_INSIDE    4       /* between FROM and TO */
 197 #define CHECK_BORDER    (CHECK_HEAD | CHECK_TAIL)
 198 #define CHECK_ALL       (CHECK_BORDER | CHECK_INSIDE)
 199
 200 extern Lisp_Object Qcomposition;
 201 extern Lisp_Object composition_hash_table;
 202
 203 extern int get_composition_id P_ ((int, int, int, Lisp_Object, Lisp_Object));
 204 extern int find_composition P_ ((int, int, int *, int *, Lisp_Object *,
 205                                  Lisp_Object));
 206 extern void update_compositions P_ ((int, int, int));
 207 extern void make_composition_value_copy P_ ((Lisp_Object));
 208 extern void compose_region P_ ((int, int, Lisp_Object, Lisp_Object,
 209                                 Lisp_Object));
 210 extern void syms_of_composite P_ ((void));
 211 extern void compose_text P_ ((int, int, Lisp_Object, Lisp_Object,
 212                               Lisp_Object));
 213 extern void compose_chars_in_text P_ ((int, int, Lisp_Object));
 214
 215 #endif /* not EMACS_COMPOSITE_H */