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, 1998, 1999, 2000, 2001, 2002, 2003, 2004, 2005, 2006
   5      National Institute of Advanced Industrial Science and Technology (AIST)
   6      Registration Number H14PRO021
   7    Copyright (C) 2003, 2006
   8      National Institute of Advanced Industrial Science and Technology (AIST)
   9      Registration Number H13PRO009
  10
  11 This file is part of GNU Emacs.
  12
  13 GNU Emacs is free software; you can redistribute it and/or modify
  14 it under the terms of the GNU General Public License as published by
  15 the Free Software Foundation; either version 2, or (at your option)
  16 any later version.
  17
  18 GNU Emacs is distributed in the hope that it will be useful,
  19 but WITHOUT ANY WARRANTY; without even the implied warranty of
  20 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  21 GNU General Public License for more details.
  22
  23 You should have received a copy of the GNU General Public License
  24 along with GNU Emacs; see the file COPYING.  If not, write to
  25 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  26 Boston, MA 02110-1301, USA.  */
  27
  28 #ifndef EMACS_COMPOSITE_H
  29 #define EMACS_COMPOSITE_H
  30
  31 /* Methods to display a sequence of components of a composition.  */
  32 enum composition_method {
  33   /* Compose relatively without alternate characters.  */
  34   COMPOSITION_RELATIVE,
  35   /* Compose by specified composition rules.  This is not used in
  36      Emacs 21 but we need it to decode files saved in the older
  37      versions of Emacs.  */
  38   COMPOSITION_WITH_RULE,
  39   /* Compose relatively with alternate characters.  */
  40   COMPOSITION_WITH_ALTCHARS,
  41   /* Compose by specified composition rules with alternate characters.  */
  42   COMPOSITION_WITH_RULE_ALTCHARS,
  43 #ifdef USE_FONT_BACKEND
  44   /* Compose by specified lispy glyph-string.  */
  45   COMPOSITION_WITH_GLYPH_STRING,
  46 #endif  /* USE_FONT_BACKEND */
  47   /* This is not a method.  */
  48   COMPOSITION_NO
  49 };
  50
  51 /* Maximum number of compoments a single composition can have.  */
  52 #define MAX_COMPOSITION_COMPONENTS 16
  53
  54 /* These macros access information about a composition that
  55    has `composition' property PROP.  PROP is:
  56         ((LENGTH . COMPONENTS) . MODIFICATION-FUNC)
  57    or
  58         (COMPOSITION-ID . (LENGTH COMPONENTS . MODIFICATION-FUNC))
  59    They don't check validity of PROP.  */
  60
  61 /* Temporary variable used only in the following macros.  */
  62 extern Lisp_Object composition_temp;
  63
  64 /* Return 1 iff the composition is already registered.  */
  65 #define COMPOSITION_REGISTERD_P(prop) INTEGERP (XCAR (prop))
  66
  67 /* Return ID number of the already registered composition.  */
  68 #define COMPOSITION_ID(prop) XINT (XCAR (prop))
  69
  70 /* Return length of the composition.  */
  71 #define COMPOSITION_LENGTH(prop)        \
  72   (COMPOSITION_REGISTERD_P (prop)       \
  73    ? XINT (XCAR (XCDR (prop)))          \
  74    : XINT (XCAR (XCAR (prop))))
  75
  76 /* Return components of the composition.  */
  77 #define COMPOSITION_COMPONENTS(prop)    \
  78   (COMPOSITION_REGISTERD_P (prop)       \
  79    ? XCAR (XCDR (XCDR (prop)))          \
  80    : XCDR (XCAR (prop)))
  81
  82 /* Return modification function of the composition.  */
  83 #define COMPOSITION_MODIFICATION_FUNC(prop)     \
  84   (COMPOSITION_REGISTERD_P (prop)               \
  85    ? XCDR (XCDR (XCDR (prop)))                  \
  86    : CONSP (prop) ? XCDR (prop) : Qnil)
  87
  88 /* Return the method of composition.  */
  89 #define COMPOSITION_METHOD(prop)                                        \
  90   (COMPOSITION_REGISTERD_P (prop)                                       \
  91    ? composition_table[COMPOSITION_ID (prop)]->method                   \
  92    : (composition_temp = XCDR (XCAR (prop)),                            \
  93       (NILP (composition_temp)                                          \
  94        ? COMPOSITION_RELATIVE                                           \
  95        : ((INTEGERP (composition_temp) || STRINGP (composition_temp))   \
  96           ? COMPOSITION_WITH_ALTCHARS                                   \
  97           : COMPOSITION_WITH_RULE_ALTCHARS))))
  98
  99 /* Return 1 iff the composition is valid.  It is valid if length of
 100    the composition equals to (END - START).  */
 101 #define COMPOSITION_VALID_P(start, end, prop)                   \
 102   (CONSP (prop)                                                 \
 103    && (COMPOSITION_REGISTERD_P (prop)                           \
 104        ? (COMPOSITION_ID (prop) >= 0                            \
 105           && COMPOSITION_ID (prop) <= n_compositions            \
 106           && CONSP (XCDR (prop)))                               \
 107        : (composition_temp = XCAR (prop),                       \
 108           (CONSP (composition_temp)                             \
 109            && (composition_temp = XCDR (composition_temp),      \
 110                (NILP (composition_temp)                         \
 111                 || STRINGP (composition_temp)                   \
 112                 || VECTORP (composition_temp)                   \
 113                 || INTEGERP (composition_temp)                  \
 114                 || CONSP (composition_temp))))))                \
 115    && (end - start) == COMPOSITION_LENGTH (prop))
 116
 117 /* Return the Nth glyph of composition specified by CMP.  CMP is a
 118    pointer to `struct composition'. */
 119 #define COMPOSITION_GLYPH(cmp, n)                                       \
 120   XINT (XVECTOR (XVECTOR (XHASH_TABLE (composition_hash_table)          \
 121                           ->key_and_value)                              \
 122                  ->contents[cmp->hash_index * 2])                       \
 123         ->contents[cmp->method == COMPOSITION_WITH_RULE_ALTCHARS        \
 124                   ? (n) * 2 : (n)])
 125
 126 /* Return the encoded composition rule to compose the Nth glyph of
 127    rule-base composition specified by CMP.  CMP is a pointer to
 128    `struct composition'. */
 129 #define COMPOSITION_RULE(cmp, n)                                \
 130   XINT (XVECTOR (XVECTOR (XHASH_TABLE (composition_hash_table)  \
 131                           ->key_and_value)                      \
 132                  ->contents[cmp->hash_index * 2])               \
 133         ->contents[(n) * 2 - 1])
 134
 135 /* Decode encoded composition rule RULE_CODE into GREF (global
 136    reference point code), NREF (new reference point code), XOFF
 137    (horizontal offset) YOFF (vertical offset).  Don't check RULE_CODE,
 138    always set GREF and NREF to valid values.  By side effect,
 139    RULE_CODE is modified.  */
 140
 141 #define COMPOSITION_DECODE_RULE(rule_code, gref, nref, xoff, yoff)      \
 142   do {                                                                  \
 143     xoff = (rule_code) >> 16;                                           \
 144     yoff = ((rule_code) >> 8) & 0xFF;                                   \
 145     rule_code &= 0xFF;                                                  \
 146     gref = (rule_code) / 12;                                            \
 147     if (gref > 12) gref = 11;                                           \
 148     nref = (rule_code) % 12;                                            \
 149   } while (0)
 150
 151 /* Return encoded composition rule for the pair of global reference
 152    point GREF and new reference point NREF.  If arguments are invalid,
 153    return -1. */
 154 #define COMPOSITION_ENCODE_RULE(gref, nref)             \
 155   ((unsigned) (gref) < 12 && (unsigned) (nref) < 12     \
 156    ? (gref) * 12 + (nref) : -1)
 157
 158 /* Data structure that records information about a composition
 159    currently used in some buffers or strings.
 160
 161    When a composition is assigned an ID number (by
 162    get_composition_id), this structure is allocated for the
 163    composition and linked in composition_table[ID].
 164
 165    Identical compositions appearing at different places have the same
 166    ID, and thus share the same instance of this structure.  */
 167
 168 struct composition {
 169   /* Number of glyphs of the composition components.  */
 170   unsigned glyph_len;
 171
 172   /* Width, ascent, and descent pixels of the composition.  */
 173   short pixel_width, ascent, descent;
 174
 175   short lbearing, rbearing;
 176
 177   /* How many columns the overall glyphs occupy on the screen.  This
 178      gives an approximate value for column calculation in
 179      Fcurrent_column, and etc.  */
 180   unsigned short width;
 181
 182   /* Method of the composition.  */
 183   enum composition_method method;
 184
 185   /* Index to the composition hash table.  */
 186   int hash_index;
 187
 188   /* For which font we have calculated the remaining members.  The
 189      actual type is device dependent.  */
 190   void *font;
 191
 192   /* Pointer to an array of x-offset and y-offset (by pixels) of
 193      glyphs.  This points to a sufficient memory space (sizeof (int) *
 194      glyph_len * 2) that is allocated when the composition is
 195      registered in composition_table.  X-offset and Y-offset of Nth
 196      glyph are (2N)th and (2N+1)th elements respectively.  */
 197   short *offsets;
 198 };
 199
 200 /* Table of pointers to the structure `composition' indexed by
 201    COMPOSITION-ID.  */
 202 extern struct composition **composition_table;
 203 /* Number of the currently registered compositions.  */
 204 extern int n_compositions;
 205
 206 /* Mask bits for CHECK_MASK arg to update_compositions.
 207    For a change in the region FROM and TO, check compositions ... */
 208 #define CHECK_HEAD      1       /* adjacent to FROM */
 209 #define CHECK_TAIL      2       /* adjacent to TO */
 210 #define CHECK_INSIDE    4       /* between FROM and TO */
 211 #define CHECK_BORDER    (CHECK_HEAD | CHECK_TAIL)
 212 #define CHECK_ALL       (CHECK_BORDER | CHECK_INSIDE)
 213
 214 extern Lisp_Object Qcomposition;
 215 extern Lisp_Object composition_hash_table;
 216 extern Lisp_Object Qauto_composed;
 217 extern Lisp_Object Vauto_composition_function;
 218 extern Lisp_Object Qauto_composition_function;
 219
 220 extern int get_composition_id P_ ((int, int, int, Lisp_Object, Lisp_Object));
 221 extern int find_composition P_ ((int, int, EMACS_INT *, EMACS_INT *, Lisp_Object *,
 222                                  Lisp_Object));
 223 extern void update_compositions P_ ((EMACS_INT, EMACS_INT, int));
 224 extern void make_composition_value_copy P_ ((Lisp_Object));
 225 extern void compose_region P_ ((int, int, Lisp_Object, Lisp_Object,
 226                                 Lisp_Object));
 227 extern void syms_of_composite P_ ((void));
 228 extern void compose_text P_ ((int, int, Lisp_Object, Lisp_Object,
 229                               Lisp_Object));
 230
 231 #endif /* not EMACS_COMPOSITE_H */
 232
 233 /* arch-tag: 59524d89-c645-47bd-b5e6-65e861690118
 234    (do not change this comment) */