src/hb-unicode.cc

   1 /*
   2  * Copyright © 2009  Red Hat, Inc.
   3  * Copyright © 2011 Codethink Limited
   4  * Copyright © 2010,2011  Google, Inc.
   5  *
   6  *  This is part of HarfBuzz, a text shaping library.
   7  *
   8  * Permission is hereby granted, without written agreement and without
   9  * license or royalty fees, to use, copy, modify, and distribute this
  10  * software and its documentation for any purpose, provided that the
  11  * above copyright notice and the following two paragraphs appear in
  12  * all copies of this software.
  13  *
  14  * IN NO EVENT SHALL THE COPYRIGHT HOLDER BE LIABLE TO ANY PARTY FOR
  15  * DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
  16  * ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN
  17  * IF THE COPYRIGHT HOLDER HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH
  18  * DAMAGE.
  19  *
  20  * THE COPYRIGHT HOLDER SPECIFICALLY DISCLAIMS ANY WARRANTIES, INCLUDING,
  21  * BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
  22  * FITNESS FOR A PARTICULAR PURPOSE.  THE SOFTWARE PROVIDED HEREUNDER IS
  23  * ON AN "AS IS" BASIS, AND THE COPYRIGHT HOLDER HAS NO OBLIGATION TO
  24  * PROVIDE MAINTENANCE, SUPPORT, UPDATES, ENHANCEMENTS, OR MODIFICATIONS.
  25  *
  26  * Red Hat Author(s): Behdad Esfahbod
  27  * Codethink Author(s): Ryan Lortie
  28  * Google Author(s): Behdad Esfahbod
  29  */
  30
  31 #include "hb-private.hh"
  32
  33 #include "hb-unicode-private.hh"
  34
  35 HB_BEGIN_DECLS
  36
  37
  38 /*
  39  * hb_unicode_funcs_t
  40  */
  41
  42 static unsigned int
  43 hb_unicode_get_combining_class_nil (hb_unicode_funcs_t *ufuncs    HB_UNUSED,
  44                                     hb_codepoint_t      unicode   HB_UNUSED,
  45                                     void               *user_data HB_UNUSED)
  46 {
  47   return 0;
  48 }
  49
  50 static unsigned int
  51 hb_unicode_get_eastasian_width_nil (hb_unicode_funcs_t *ufuncs    HB_UNUSED,
  52                                     hb_codepoint_t      unicode   HB_UNUSED,
  53                                     void               *user_data HB_UNUSED)
  54 {
  55   return 1;
  56 }
  57
  58 static hb_unicode_general_category_t
  59 hb_unicode_get_general_category_nil (hb_unicode_funcs_t *ufuncs    HB_UNUSED,
  60                                      hb_codepoint_t      unicode   HB_UNUSED,
  61                                      void               *user_data HB_UNUSED)
  62 {
  63   return HB_UNICODE_GENERAL_CATEGORY_OTHER_LETTER;
  64 }
  65
  66 static hb_codepoint_t
  67 hb_unicode_get_mirroring_nil (hb_unicode_funcs_t *ufuncs    HB_UNUSED,
  68                               hb_codepoint_t      unicode   HB_UNUSED,
  69                               void               *user_data HB_UNUSED)
  70 {
  71   return unicode;
  72 }
  73
  74 static hb_script_t
  75 hb_unicode_get_script_nil (hb_unicode_funcs_t *ufuncs    HB_UNUSED,
  76                            hb_codepoint_t      unicode   HB_UNUSED,
  77                            void               *user_data HB_UNUSED)
  78 {
  79   return HB_SCRIPT_UNKNOWN;
  80 }
  81
  82
  83 hb_unicode_funcs_t _hb_unicode_funcs_nil = {
  84   HB_REFERENCE_COUNT_INVALID, /* ref_count */
  85   NULL, /* parent */
  86   TRUE, /* immutable */
  87   {
  88     hb_unicode_get_combining_class_nil,
  89     hb_unicode_get_eastasian_width_nil,
  90     hb_unicode_get_general_category_nil,
  91     hb_unicode_get_mirroring_nil,
  92     hb_unicode_get_script_nil,
  93   }
  94 };
  95
  96
  97 hb_unicode_funcs_t *
  98 hb_unicode_funcs_create (hb_unicode_funcs_t *parent)
  99 {
 100   hb_unicode_funcs_t *ufuncs;
 101
 102   if (!HB_OBJECT_DO_CREATE (hb_unicode_funcs_t, ufuncs))
 103     return &_hb_unicode_funcs_nil;
 104
 105   if (parent != NULL)
 106   {
 107     hb_unicode_funcs_make_immutable (parent);
 108     ufuncs->parent = hb_unicode_funcs_reference (parent);
 109
 110     ufuncs->get = parent->get;
 111
 112     /* We can safely copy user_data from parent since we hold a reference
 113      * onto it and it's immutable.  We should not copy the destroy notifiers
 114      * though. */
 115     ufuncs->user_data = parent->user_data;
 116   }
 117   else
 118   {
 119     ufuncs->get = _hb_unicode_funcs_nil.get;
 120   }
 121
 122   return ufuncs;
 123 }
 124
 125 hb_unicode_funcs_t *
 126 hb_unicode_funcs_reference (hb_unicode_funcs_t *ufuncs)
 127 {
 128   HB_OBJECT_DO_REFERENCE (ufuncs);
 129 }
 130
 131 void
 132 hb_unicode_funcs_destroy (hb_unicode_funcs_t *ufuncs)
 133 {
 134   HB_OBJECT_DO_DESTROY (ufuncs);
 135
 136 #define DESTROY(name) if (ufuncs->destroy.name) ufuncs->destroy.name (ufuncs->user_data.name)
 137   DESTROY (combining_class);
 138   DESTROY (eastasian_width);
 139   DESTROY (general_category);
 140   DESTROY (mirroring);
 141   DESTROY (script);
 142 #undef DESTROY
 143
 144   if (ufuncs->parent != NULL)
 145     hb_unicode_funcs_destroy (ufuncs->parent);
 146
 147   free (ufuncs);
 148 }
 149
 150 void
 151 hb_unicode_funcs_make_immutable (hb_unicode_funcs_t *ufuncs)
 152 {
 153   if (HB_OBJECT_IS_INERT (ufuncs))
 154     return;
 155
 156   ufuncs->immutable = TRUE;
 157 }
 158
 159 hb_bool_t
 160 hb_unicode_funcs_is_immutable (hb_unicode_funcs_t *ufuncs)
 161 {
 162   return ufuncs->immutable;
 163 }
 164
 165 hb_unicode_funcs_t *
 166 hb_unicode_funcs_get_parent (hb_unicode_funcs_t *ufuncs)
 167 {
 168   return ufuncs->parent;
 169 }
 170
 171
 172 #define IMPLEMENT(return_type, name)                                           \
 173                                                                                \
 174 void                                                                           \
 175 hb_unicode_funcs_set_##name##_func (hb_unicode_funcs_t             *ufuncs,    \
 176                                     hb_unicode_get_##name##_func_t  func,      \
 177                                     void                           *user_data, \
 178                                     hb_destroy_func_t               destroy)   \
 179 {                                                                              \
 180   if (ufuncs->immutable)                                                       \
 181     return;                                                                    \
 182                                                                                \
 183   if (ufuncs->destroy.name)                                                    \
 184     ufuncs->destroy.name (ufuncs->user_data.name);                             \
 185                                                                                \
 186   if (func) {                                                                  \
 187     ufuncs->get.name = func;                                                   \
 188     ufuncs->user_data.name = user_data;                                        \
 189     ufuncs->destroy.name = destroy;                                            \
 190   } else if (ufuncs->parent != NULL) {                                         \
 191     ufuncs->get.name = ufuncs->parent->get.name;                               \
 192     ufuncs->user_data.name = ufuncs->parent->user_data.name;                   \
 193     ufuncs->destroy.name = NULL;                                               \
 194   } else {                                                                     \
 195     ufuncs->get.name = hb_unicode_get_##name##_nil;                            \
 196     ufuncs->user_data.name = NULL;                                             \
 197     ufuncs->destroy.name = NULL;                                               \
 198   }                                                                            \
 199 }                                                                              \
 200                                                                                \
 201 return_type                                                                    \
 202 hb_unicode_get_##name (hb_unicode_funcs_t *ufuncs,                             \
 203                        hb_codepoint_t      unicode)                            \
 204 {                                                                              \
 205   return ufuncs->get.name (ufuncs, unicode, ufuncs->user_data.name);           \
 206 }
 207
 208 IMPLEMENT (unsigned int, combining_class)
 209 IMPLEMENT (unsigned int, eastasian_width)
 210 IMPLEMENT (hb_unicode_general_category_t, general_category)
 211 IMPLEMENT (hb_codepoint_t, mirroring)
 212 IMPLEMENT (hb_script_t, script)
 213
 214 #undef IMPLEMENT
 215
 216
 217 HB_END_DECLS