source/libs/cairo/cairo-src/src/cairo-font-face.c

   1 /* -*- Mode: c; c-basic-offset: 4; indent-tabs-mode: t; tab-width: 8; -*- */
   2 /* cairo - a vector graphics library with display and print output
   3  *
   4  * Copyright © 2002 University of Southern California
   5  * Copyright © 2005 Red Hat Inc.
   6  *
   7  * This library is free software; you can redistribute it and/or
   8  * modify it either under the terms of the GNU Lesser General Public
   9  * License version 2.1 as published by the Free Software Foundation
  10  * (the "LGPL") or, at your option, under the terms of the Mozilla
  11  * Public License Version 1.1 (the "MPL"). If you do not alter this
  12  * notice, a recipient may use your version of this file under either
  13  * the MPL or the LGPL.
  14  *
  15  * You should have received a copy of the LGPL along with this library
  16  * in the file COPYING-LGPL-2.1; if not, write to the Free Software
  17  * Foundation, Inc., 51 Franklin Street, Suite 500, Boston, MA 02110-1335, USA
  18  * You should have received a copy of the MPL along with this library
  19  * in the file COPYING-MPL-1.1
  20  *
  21  * The contents of this file are subject to the Mozilla Public License
  22  * Version 1.1 (the "License"); you may not use this file except in
  23  * compliance with the License. You may obtain a copy of the License at
  24  * http://www.mozilla.org/MPL/
  25  *
  26  * This software is distributed on an "AS IS" basis, WITHOUT WARRANTY
  27  * OF ANY KIND, either express or implied. See the LGPL or the MPL for
  28  * the specific language governing rights and limitations.
  29  *
  30  * The Original Code is the cairo graphics library.
  31  *
  32  * The Initial Developer of the Original Code is University of Southern
  33  * California.
  34  *
  35  * Contributor(s):
  36  *      Carl D. Worth <cworth@cworth.org>
  37  *      Graydon Hoare <graydon@redhat.com>
  38  *      Owen Taylor <otaylor@redhat.com>
  39  */
  40
  41 #include "cairoint.h"
  42 #include "cairo-error-private.h"
  43
  44 /**
  45  * SECTION:cairo-font-face
  46  * @Title: cairo_font_face_t
  47  * @Short_Description: Base class for font faces
  48  * @See_Also: #cairo_scaled_font_t
  49  *
  50  * #cairo_font_face_t represents a particular font at a particular weight,
  51  * slant, and other characteristic but no size, transformation, or size.
  52  *
  53  * Font faces are created using <firstterm>font-backend</firstterm>-specific
  54  * constructors, typically of the form
  55  * <function>cairo_<emphasis>backend</emphasis>_font_face_create(<!-- -->)</function>,
  56  * or implicitly using the <firstterm>toy</firstterm> text API by way of
  57  * cairo_select_font_face().  The resulting face can be accessed using
  58  * cairo_get_font_face().
  59  **/
  60
  61 /* #cairo_font_face_t */
  62
  63 const cairo_font_face_t _cairo_font_face_nil = {
  64     { 0 },                              /* hash_entry */
  65     CAIRO_STATUS_NO_MEMORY,             /* status */
  66     CAIRO_REFERENCE_COUNT_INVALID,      /* ref_count */
  67     { 0, 0, 0, NULL },                  /* user_data */
  68     NULL
  69 };
  70 const cairo_font_face_t _cairo_font_face_nil_file_not_found = {
  71     { 0 },                              /* hash_entry */
  72     CAIRO_STATUS_FILE_NOT_FOUND,        /* status */
  73     CAIRO_REFERENCE_COUNT_INVALID,      /* ref_count */
  74     { 0, 0, 0, NULL },                  /* user_data */
  75     NULL
  76 };
  77
  78 cairo_status_t
  79 _cairo_font_face_set_error (cairo_font_face_t *font_face,
  80                             cairo_status_t     status)
  81 {
  82     if (status == CAIRO_STATUS_SUCCESS)
  83         return status;
  84
  85     /* Don't overwrite an existing error. This preserves the first
  86      * error, which is the most significant. */
  87     _cairo_status_set_error (&font_face->status, status);
  88
  89     return _cairo_error (status);
  90 }
  91
  92 void
  93 _cairo_font_face_init (cairo_font_face_t               *font_face,
  94                        const cairo_font_face_backend_t *backend)
  95 {
  96     CAIRO_MUTEX_INITIALIZE ();
  97
  98     font_face->status = CAIRO_STATUS_SUCCESS;
  99     CAIRO_REFERENCE_COUNT_INIT (&font_face->ref_count, 1);
 100     font_face->backend = backend;
 101
 102     _cairo_user_data_array_init (&font_face->user_data);
 103 }
 104
 105 /**
 106  * cairo_font_face_reference:
 107  * @font_face: a #cairo_font_face_t, (may be %NULL in which case this
 108  * function does nothing).
 109  *
 110  * Increases the reference count on @font_face by one. This prevents
 111  * @font_face from being destroyed until a matching call to
 112  * cairo_font_face_destroy() is made.
 113  *
 114  * The number of references to a #cairo_font_face_t can be get using
 115  * cairo_font_face_get_reference_count().
 116  *
 117  * Return value: the referenced #cairo_font_face_t.
 118  *
 119  * Since: 1.0
 120  **/
 121 cairo_font_face_t *
 122 cairo_font_face_reference (cairo_font_face_t *font_face)
 123 {
 124     if (font_face == NULL ||
 125         CAIRO_REFERENCE_COUNT_IS_INVALID (&font_face->ref_count))
 126         return font_face;
 127
 128     /* We would normally assert that we have a reference here but we
 129      * can't get away with that due to the zombie case as documented
 130      * in _cairo_ft_font_face_destroy. */
 131
 132     _cairo_reference_count_inc (&font_face->ref_count);
 133
 134     return font_face;
 135 }
 136 slim_hidden_def (cairo_font_face_reference);
 137
 138 static inline cairo_bool_t
 139 __put(cairo_reference_count_t *v)
 140 {
 141     int c, old;
 142
 143     c = CAIRO_REFERENCE_COUNT_GET_VALUE(v);
 144     while (c != 1 && (old = _cairo_atomic_int_cmpxchg_return_old(&v->ref_count, c, c - 1)) != c)
 145         c = old;
 146
 147     return c != 1;
 148 }
 149
 150 cairo_bool_t
 151 _cairo_font_face_destroy (void *abstract_face)
 152 {
 153 #if 0 /* Nothing needs to be done, we can just drop the last reference */
 154     cairo_font_face_t *font_face = abstract_face;
 155     return _cairo_reference_count_dec_and_test (&font_face->ref_count);
 156 #endif
 157     return TRUE;
 158 }
 159
 160 /**
 161  * cairo_font_face_destroy:
 162  * @font_face: a #cairo_font_face_t
 163  *
 164  * Decreases the reference count on @font_face by one. If the result
 165  * is zero, then @font_face and all associated resources are freed.
 166  * See cairo_font_face_reference().
 167  *
 168  * Since: 1.0
 169  **/
 170 void
 171 cairo_font_face_destroy (cairo_font_face_t *font_face)
 172 {
 173     if (font_face == NULL ||
 174         CAIRO_REFERENCE_COUNT_IS_INVALID (&font_face->ref_count))
 175         return;
 176
 177     assert (CAIRO_REFERENCE_COUNT_HAS_REFERENCE (&font_face->ref_count));
 178
 179     /* We allow resurrection to deal with some memory management for the
 180      * FreeType backend where cairo_ft_font_face_t and cairo_ft_unscaled_font_t
 181      * need to effectively mutually reference each other
 182      */
 183     if (__put (&font_face->ref_count))
 184         return;
 185
 186     if (! font_face->backend->destroy (font_face))
 187         return;
 188
 189     _cairo_user_data_array_fini (&font_face->user_data);
 190
 191     free (font_face);
 192 }
 193 slim_hidden_def (cairo_font_face_destroy);
 194
 195 /**
 196  * cairo_font_face_get_type:
 197  * @font_face: a font face
 198  *
 199  * This function returns the type of the backend used to create
 200  * a font face. See #cairo_font_type_t for available types.
 201  *
 202  * Return value: The type of @font_face.
 203  *
 204  * Since: 1.2
 205  **/
 206 cairo_font_type_t
 207 cairo_font_face_get_type (cairo_font_face_t *font_face)
 208 {
 209     if (CAIRO_REFERENCE_COUNT_IS_INVALID (&font_face->ref_count))
 210         return CAIRO_FONT_TYPE_TOY;
 211
 212     return font_face->backend->type;
 213 }
 214
 215 /**
 216  * cairo_font_face_get_reference_count:
 217  * @font_face: a #cairo_font_face_t
 218  *
 219  * Returns the current reference count of @font_face.
 220  *
 221  * Return value: the current reference count of @font_face.  If the
 222  * object is a nil object, 0 will be returned.
 223  *
 224  * Since: 1.4
 225  **/
 226 unsigned int
 227 cairo_font_face_get_reference_count (cairo_font_face_t *font_face)
 228 {
 229     if (font_face == NULL ||
 230         CAIRO_REFERENCE_COUNT_IS_INVALID (&font_face->ref_count))
 231         return 0;
 232
 233     return CAIRO_REFERENCE_COUNT_GET_VALUE (&font_face->ref_count);
 234 }
 235
 236 /**
 237  * cairo_font_face_status:
 238  * @font_face: a #cairo_font_face_t
 239  *
 240  * Checks whether an error has previously occurred for this
 241  * font face
 242  *
 243  * Return value: %CAIRO_STATUS_SUCCESS or another error such as
 244  *   %CAIRO_STATUS_NO_MEMORY.
 245  *
 246  * Since: 1.0
 247  **/
 248 cairo_status_t
 249 cairo_font_face_status (cairo_font_face_t *font_face)
 250 {
 251     return font_face->status;
 252 }
 253
 254 /**
 255  * cairo_font_face_get_user_data:
 256  * @font_face: a #cairo_font_face_t
 257  * @key: the address of the #cairo_user_data_key_t the user data was
 258  * attached to
 259  *
 260  * Return user data previously attached to @font_face using the specified
 261  * key.  If no user data has been attached with the given key this
 262  * function returns %NULL.
 263  *
 264  * Return value: the user data previously attached or %NULL.
 265  *
 266  * Since: 1.0
 267  **/
 268 void *
 269 cairo_font_face_get_user_data (cairo_font_face_t           *font_face,
 270                                const cairo_user_data_key_t *key)
 271 {
 272     return _cairo_user_data_array_get_data (&font_face->user_data,
 273                                             key);
 274 }
 275 slim_hidden_def (cairo_font_face_get_user_data);
 276
 277 /**
 278  * cairo_font_face_set_user_data:
 279  * @font_face: a #cairo_font_face_t
 280  * @key: the address of a #cairo_user_data_key_t to attach the user data to
 281  * @user_data: the user data to attach to the font face
 282  * @destroy: a #cairo_destroy_func_t which will be called when the
 283  * font face is destroyed or when new user data is attached using the
 284  * same key.
 285  *
 286  * Attach user data to @font_face.  To remove user data from a font face,
 287  * call this function with the key that was used to set it and %NULL
 288  * for @data.
 289  *
 290  * Return value: %CAIRO_STATUS_SUCCESS or %CAIRO_STATUS_NO_MEMORY if a
 291  * slot could not be allocated for the user data.
 292  *
 293  * Since: 1.0
 294  **/
 295 cairo_status_t
 296 cairo_font_face_set_user_data (cairo_font_face_t           *font_face,
 297                                const cairo_user_data_key_t *key,
 298                                void                        *user_data,
 299                                cairo_destroy_func_t         destroy)
 300 {
 301     if (CAIRO_REFERENCE_COUNT_IS_INVALID (&font_face->ref_count))
 302         return font_face->status;
 303
 304     return _cairo_user_data_array_set_data (&font_face->user_data,
 305                                             key, user_data, destroy);
 306 }
 307 slim_hidden_def (cairo_font_face_set_user_data);
 308
 309 void
 310 _cairo_unscaled_font_init (cairo_unscaled_font_t               *unscaled_font,
 311                            const cairo_unscaled_font_backend_t *backend)
 312 {
 313     CAIRO_REFERENCE_COUNT_INIT (&unscaled_font->ref_count, 1);
 314     unscaled_font->backend = backend;
 315 }
 316
 317 cairo_unscaled_font_t *
 318 _cairo_unscaled_font_reference (cairo_unscaled_font_t *unscaled_font)
 319 {
 320     if (unscaled_font == NULL)
 321         return NULL;
 322
 323     assert (CAIRO_REFERENCE_COUNT_HAS_REFERENCE (&unscaled_font->ref_count));
 324
 325     _cairo_reference_count_inc (&unscaled_font->ref_count);
 326
 327     return unscaled_font;
 328 }
 329
 330 void
 331 _cairo_unscaled_font_destroy (cairo_unscaled_font_t *unscaled_font)
 332 {
 333     if (unscaled_font == NULL)
 334         return;
 335
 336     assert (CAIRO_REFERENCE_COUNT_HAS_REFERENCE (&unscaled_font->ref_count));
 337
 338     if (__put (&unscaled_font->ref_count))
 339         return;
 340
 341     if (! unscaled_font->backend->destroy (unscaled_font))
 342         return;
 343
 344     free (unscaled_font);
 345 }