src/adg/adg-dress.c

   1 /* ADG - Automatic Drawing Generation
   2  * Copyright (C) 2007,2008,2009,2010,2011,2012,2013  Nicola Fontana <ntd at entidi.it>
   3  *
   4  * This library is free software; you can redistribute it and/or
   5  * modify it under the terms of the GNU Lesser General Public
   6  * License as published by the Free Software Foundation; either
   7  * version 2 of the License, or (at your option) any later version.
   8  *
   9  * This library is distributed in the hope that it will be useful,
  10  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  11  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  12  * Lesser General Public License for more details.
  13  *
  14  * You should have received a copy of the GNU Lesser General Public
  15  * License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  17  * Boston, MA  02110-1301, USA.
  18  */
  19
  20
  21 /**
  22  * SECTION:adg-dress
  23  * @Section_Id:AdgDress
  24  * @title: AdgDress
  25  * @short_description: The ADG way to associate styles to entities
  26  *
  27  * The dress is a virtualization of an #AdgStyle instance. #AdgEntity
  28  * objects do not directly refer to #AdgStyle but use #AdgDress values
  29  * instead. This allows some advanced operations, such as overriding
  30  * a dress only in a specific entity branch of the hierarchy or
  31  * customize multiple entities at once.
  32  *
  33  * Since: 1.0
  34  **/
  35
  36 /**
  37  * AdgDress:
  38  *
  39  * An index representing a virtual #AdgStyle.
  40  *
  41  * Since: 1.0
  42  **/
  43
  44 /**
  45  * ADG_TYPE_DRESS:
  46  *
  47  * The type used to express a dress index. It is defined only for GObject
  48  * internal and should not be used directly (at least, as far as I know).
  49  *
  50  * Since: 1.0
  51  **/
  52
  53 /**
  54  * ADG_VALUE_HOLDS_DRESS:
  55  * @value: a #GValue
  56  *
  57  * Checks whether a #GValue is actually holding an #AdgDress value or not.
  58  *
  59  * Returns: %TRUE is @value is holding an #AdgDress, %FALSE otherwise
  60  *
  61  * Since: 1.0
  62  **/
  63
  64
  65 #include "adg-internal.h"
  66 #include "adg-style.h"
  67 #include "adg-dress-builtins.h"
  68
  69 #include "adg-dress.h"
  70 #include "adg-dress-private.h"
  71
  72
  73 typedef struct _AdgParamSpecDress AdgParamSpecDress;
  74
  75 struct _AdgParamSpecDress {
  76     GParamSpecInt parent;
  77     AdgDress      source_dress;
  78 };
  79
  80
  81 static AdgDress         _adg_quark_to_dress     (GQuark          quark);
  82 static void             _adg_dress_to_string    (const GValue   *src,
  83                                                  GValue         *dst);
  84 static void             _adg_string_to_dress    (const GValue   *src,
  85                                                  GValue         *dst);
  86 static void             _adg_param_class_init   (GParamSpecClass*klass);
  87 static const gchar *    _adg_dress_name         (AdgDress        dress);
  88 static gboolean         _adg_dress_is_valid     (AdgDress        dress);
  89 static gboolean         _adg_dress_is_valid_with_log
  90                                                 (AdgDress        dress);
  91 static gboolean         _adg_value_validate     (GParamSpec     *spec,
  92                                                  GValue         *value);
  93 static GArray *         _adg_array_singleton    (void) G_GNUC_CONST;
  94 static guint            _adg_array_append       (AdgDressPrivate*data);
  95 static AdgDressPrivate *_adg_array_lookup       (guint           n);
  96 static guint            _adg_array_len          (void);
  97
  98
  99 GType
 100 adg_dress_get_type(void)
 101 {
 102     static GType type = 0;
 103
 104     if (G_UNLIKELY(type == 0)) {
 105         const GTypeInfo info = { 0, };
 106
 107         type = g_type_register_static(G_TYPE_INT, "AdgDress", &info, 0);
 108
 109         g_value_register_transform_func(type, G_TYPE_STRING,
 110                                         _adg_dress_to_string);
 111         g_value_register_transform_func(G_TYPE_STRING, type,
 112                                         _adg_string_to_dress);
 113     }
 114
 115     return type;
 116 }
 117
 118 /**
 119  * adg_dress_new:
 120  * @name: the dress name
 121  * @fallback: the fallback style
 122  *
 123  * Creates a new dress. It is a convenient wrapper of adg_dress_new_full()
 124  * that uses as ancestor the G_TYPE_FROM_INSTANCE() of @fallback.
 125  *
 126  * After a succesfull call, a new reference is added to @fallback.
 127  *
 128  * Returns: (type gint) (transfer full): the new #AdgDress value or #ADG_DRESS_UNDEFINED on errors.
 129  *
 130  * Since: 1.0
 131  **/
 132 AdgDress
 133 adg_dress_new(const gchar *name, AdgStyle *fallback)
 134 {
 135     g_return_val_if_fail(ADG_IS_STYLE(fallback), ADG_DRESS_UNDEFINED);
 136
 137     return adg_dress_new_full(name, fallback, G_TYPE_FROM_INSTANCE(fallback));
 138 }
 139
 140 /**
 141  * adg_dress_new_full:
 142  * @name: the dress name
 143  * @fallback: the fallback style
 144  * @ancestor_type: the common ancestor type
 145  *
 146  * Creates a new dress, explicitely setting the ancestor type.
 147  * If @fallback is not %NULL, @ancestor_type must be present in
 148  * its hierarchy: check out the adg_dress_style_is_compatible()
 149  * documentation to know what the ancestor type is used for.
 150  *
 151  * @fallback can be %NULL, in which case a "transparent" dress
 152  * is created. This kind of dress does not change the cairo
 153  * context because there is no style to apply. Any entity could
 154  * override it to change this behavior though.
 155  *
 156  * After a succesfull call, a new reference is added to @fallback
 157  * if needed.
 158  *
 159  * Returns: (type gint) (transfer full): the new #AdgDress value or #ADG_DRESS_UNDEFINED on errors
 160  *
 161  * Since: 1.0
 162  **/
 163 AdgDress
 164 adg_dress_new_full(const gchar *name, AdgStyle *fallback, GType ancestor_type)
 165 {
 166     GQuark quark;
 167     AdgDress dress;
 168     AdgDressPrivate data;
 169
 170     g_return_val_if_fail(name != NULL, ADG_DRESS_UNDEFINED);
 171     g_return_val_if_fail(g_type_is_a(ancestor_type, ADG_TYPE_STYLE),
 172                          ADG_DRESS_UNDEFINED);
 173     g_return_val_if_fail(fallback == NULL ||
 174                          G_TYPE_CHECK_INSTANCE_TYPE(fallback, ancestor_type),
 175                          ADG_DRESS_UNDEFINED);
 176
 177     quark = g_quark_from_string(name);
 178     dress = _adg_quark_to_dress(quark);
 179
 180     if (dress > 0) {
 181         g_warning(_("%s: the `%s' name is yet used by the `%d' dress"),
 182                   G_STRLOC, name, dress);
 183         return ADG_DRESS_UNDEFINED;
 184     }
 185
 186     data.quark = quark;
 187     data.fallback = fallback;
 188     data.ancestor_type = ancestor_type;
 189
 190     if (fallback != NULL)
 191         g_object_ref(fallback);
 192
 193     return _adg_array_append(&data) - 1;
 194 }
 195
 196 /**
 197  * adg_dress_from_name:
 198  * @name: (transfer none): the name of a dress
 199  *
 200  * Gets the dress bound to a @name string. No warnings are raised
 201  * if the dress is not found.
 202  *
 203  * Returns: (transfer none): the #AdgDress code or
 204  *                           #ADG_DRESS_UNDEFINED if not found.
 205  *
 206  * Since: 1.0
 207  **/
 208 AdgDress
 209 adg_dress_from_name(const gchar *name)
 210 {
 211     return _adg_quark_to_dress(g_quark_try_string(name));
 212 }
 213
 214 /**
 215  * adg_dress_are_related:
 216  * @dress1: an #AdgDress
 217  * @dress2: another #AdgDress
 218  *
 219  * Checks whether @dress1 and @dress2 are related, that is
 220  * if they have the same ancestor type as returned by
 221  * adg_dress_get_ancestor_type().
 222  *
 223  * Returns: %TRUE if the dresses are related, %FALSE otherwise
 224  *
 225  * Since: 1.0
 226  **/
 227 gboolean
 228 adg_dress_are_related(AdgDress dress1, AdgDress dress2)
 229 {
 230     GType ancestor_type1, ancestor_type2;
 231
 232     ancestor_type1 = adg_dress_get_ancestor_type(dress1);
 233     if (ancestor_type1 <= 0)
 234         return FALSE;
 235
 236     ancestor_type2 = adg_dress_get_ancestor_type(dress2);
 237     if (ancestor_type2 <= 0)
 238         return FALSE;
 239
 240     return ancestor_type1 == ancestor_type2;
 241 }
 242
 243 /**
 244  * adg_dress_set:
 245  * @dress: a pointer to an #AdgDress
 246  * @src: the source dress
 247  *
 248  * Copies @src in @dress. This operation can be succesful only if
 249  * @dress is #ADG_DRESS_UNDEFINED or if it contains a dress related
 250  * to @src, that is adg_dress_are_related() returns %TRUE.
 251  *
 252  * Returns: %TRUE on copy done, %FALSE on copy failed or not needed
 253  *
 254  * Since: 1.0
 255  **/
 256 gboolean
 257 adg_dress_set(AdgDress *dress, AdgDress src)
 258 {
 259     if (*dress == src)
 260         return FALSE;
 261
 262     if (*dress != ADG_DRESS_UNDEFINED && !adg_dress_are_related(*dress, src))
 263         return FALSE;
 264
 265     *dress = src;
 266     return TRUE;
 267 }
 268
 269 /**
 270  * adg_dress_get_name:
 271  * @dress: an #AdgDress
 272  *
 273  * Gets the name associated to @dress. No warnings are raised if
 274  * @dress is not found.
 275  *
 276  * Returns: the requested name or %NULL if not found
 277  *
 278  * Since: 1.0
 279  **/
 280 const gchar *
 281 adg_dress_get_name(AdgDress dress)
 282 {
 283     if (!_adg_dress_is_valid(dress))
 284         return NULL;
 285
 286     return g_quark_to_string(_adg_array_lookup(dress)->quark);
 287 }
 288
 289 /**
 290  * adg_dress_get_ancestor_type:
 291  * @dress: an #AdgDress
 292  *
 293  * Gets the base type that should be present in every #AdgStyle
 294  * acceptable by @dress.  No warnings are raised if @dress
 295  * is not found.
 296  *
 297  * Returns: the ancestor type or %0 on errors
 298  *
 299  * Since: 1.0
 300  **/
 301 GType
 302 adg_dress_get_ancestor_type(AdgDress dress)
 303 {
 304     AdgDressPrivate *data;
 305
 306     if (!_adg_dress_is_valid(dress))
 307         return 0;
 308
 309     data = _adg_array_lookup(dress);
 310
 311     return data->ancestor_type;
 312 }
 313
 314 /**
 315  * adg_dress_set_fallback:
 316  * @dress: an #AdgDress
 317  * @fallback: the new fallback style
 318  *
 319  * Associates a new @fallback style to @dress. If the dress does
 320  * not exist (it was not previously created by adg_dress_new()),
 321  * a warning message is raised and the function fails.
 322  *
 323  * @fallback is checked for compatibily with @dress. Any dress holds
 324  * an ancestor type: if this type is not found in the @fallback
 325  * hierarchy, a warning message is raised and the function fails.
 326  *
 327  * After a succesfull call, the reference to the previous fallback
 328  * (if any) is dropped while a new reference to @fallback is added.
 329  *
 330  * Since: 1.0
 331  **/
 332 void
 333 adg_dress_set_fallback(AdgDress dress, AdgStyle *fallback)
 334 {
 335     AdgDressPrivate *data;
 336
 337     if (!_adg_dress_is_valid_with_log(dress))
 338         return;
 339
 340     data = _adg_array_lookup(dress);
 341
 342     if (data->fallback == fallback)
 343         return;
 344
 345     /* Check if the new fallback style is compatible with this dress */
 346     if (fallback != NULL && !adg_dress_style_is_compatible(dress, fallback)) {
 347         g_warning(_("%s: the fallback style of `%d' (%s) must be a `%s' derived type, but a `%s' has been provided"),
 348                   G_STRLOC, dress, _adg_dress_name(dress),
 349                   g_type_name(data->ancestor_type),
 350                   g_type_name(G_TYPE_FROM_INSTANCE(fallback)));
 351         return;
 352     }
 353
 354     if (data->fallback != NULL)
 355         g_object_unref(data->fallback);
 356
 357     data->fallback = fallback;
 358
 359     if (data->fallback != NULL)
 360         g_object_ref(data->fallback);
 361 }
 362
 363 /**
 364  * adg_dress_get_fallback:
 365  * @dress: an #AdgDress
 366  *
 367  * Gets the fallback style associated to @dress. No warnings
 368  * are raised if the dress is not found. The returned style
 369  * is owned by dress and should not be freed or modified.
 370  *
 371  * Returns: (transfer none): the requested #AdgStyle derived instance
 372  *                           or %NULL if not set.
 373  *
 374  * Since: 1.0
 375  **/
 376 AdgStyle *
 377 adg_dress_get_fallback(AdgDress dress)
 378 {
 379     AdgDressPrivate *data;
 380
 381     if (!_adg_dress_is_valid(dress))
 382         return NULL;
 383
 384     data = _adg_array_lookup(dress);
 385
 386     return data->fallback;
 387 }
 388
 389 /**
 390  * adg_dress_style_is_compatible:
 391  * @dress: an #AdgDress
 392  * @style: the #AdgStyle to check
 393  *
 394  * Checks whether @style is compatible with @dress, that is if
 395  * @style has the ancestor style type (as returned by
 396  * adg_dress_get_ancestor_type()) in its hierarchy.
 397  *
 398  * Returns: %TRUE if @dress can accept @style, %FALSE otherwise
 399  *
 400  * Since: 1.0
 401  **/
 402 gboolean
 403 adg_dress_style_is_compatible(AdgDress dress, AdgStyle *style)
 404 {
 405     GType ancestor_type = adg_dress_get_ancestor_type(dress);
 406
 407     g_return_val_if_fail(ancestor_type > 0, FALSE);
 408     g_return_val_if_fail(ADG_IS_STYLE(style), FALSE);
 409
 410     return G_TYPE_CHECK_INSTANCE_TYPE(style, ancestor_type);
 411 }
 412
 413
 414 static AdgDress
 415 _adg_quark_to_dress(GQuark quark)
 416 {
 417     AdgDress dress;
 418     AdgDressPrivate *data;
 419
 420     for (dress = 0; dress < _adg_array_len(); ++dress) {
 421         data = _adg_array_lookup(dress);
 422
 423         if (data->quark == quark)
 424             return dress;
 425     }
 426
 427     return ADG_DRESS_UNDEFINED;
 428 }
 429
 430 static void
 431 _adg_dress_to_string(const GValue *src, GValue *dst)
 432 {
 433     g_value_set_string(dst, adg_dress_get_name(g_value_get_int(src)));
 434 }
 435
 436 static void
 437 _adg_string_to_dress(const GValue *src, GValue *dst)
 438 {
 439     g_value_set_int(dst, adg_dress_from_name(g_value_get_string(src)));
 440 }
 441
 442 GType
 443 _adg_param_spec_dress_get_type(void)
 444 {
 445     static GType type = 0;
 446
 447     if (G_UNLIKELY(type == 0)) {
 448         const GTypeInfo info = {
 449             sizeof(GParamSpecClass),
 450             NULL,
 451             NULL,
 452             (GClassInitFunc) _adg_param_class_init,
 453             NULL,
 454             NULL,
 455             sizeof(AdgParamSpecDress),
 456             0,
 457         };
 458
 459         type = g_type_register_static(G_TYPE_PARAM_INT, "AdgParamSpecDress",
 460                                       &info, 0);
 461     }
 462
 463     return type;
 464 }
 465
 466 static void
 467 _adg_param_class_init(GParamSpecClass *klass)
 468 {
 469     klass->value_type = ADG_TYPE_DRESS;
 470     klass->value_validate = _adg_value_validate;
 471 }
 472
 473 static const gchar *
 474 _adg_dress_name(AdgDress dress)
 475 {
 476     const gchar *name = adg_dress_get_name(dress);
 477
 478     if (name == NULL) {
 479         name = _("(UNDEFINED)");
 480     }
 481
 482     return name;
 483 }
 484
 485 static gboolean
 486 _adg_dress_is_valid(AdgDress dress)
 487 {
 488     return dress > 0 && dress < _adg_array_len();
 489 }
 490
 491 static gboolean
 492 _adg_dress_is_valid_with_log(AdgDress dress)
 493 {
 494     if (!_adg_dress_is_valid(dress)) {
 495         g_warning(_("%s: the dress `%d' is undefined"), G_STRLOC, dress);
 496         return FALSE;
 497     }
 498
 499     return TRUE;
 500 }
 501
 502 static gboolean
 503 _adg_value_validate(GParamSpec *spec, GValue *value)
 504 {
 505     AdgParamSpecDress *fspec;
 506     AdgDress *dress;
 507     AdgDress wanted_dress;
 508
 509     fspec = (AdgParamSpecDress *) spec;
 510     dress = &value->data[0].v_int;
 511     wanted_dress = *dress;
 512
 513     /* Fallback to the source dress, returned in case of errors */
 514     *dress = fspec->source_dress;
 515
 516     /* This method will fail (that is, it leaves *dress untouched)
 517      * if the current *dress value (source_dress) and wanted_dress
 518      * are not related */
 519     adg_dress_set(dress, wanted_dress);
 520
 521     return *dress != wanted_dress;
 522 }
 523
 524
 525 /**
 526  * adg_param_spec_dress:
 527  * @name: canonical name
 528  * @nick: nickname of the param
 529  * @blurb: brief desciption
 530  * @dress: the #AdgDress dress
 531  * @flags: a combination of #GParamFlags
 532  *
 533  * Creates a param spec to hold a dress value.
 534  *
 535  * Returns: (transfer none): the newly allocated #GParamSpec.
 536  *
 537  * Since: 1.0
 538  **/
 539 GParamSpec *
 540 adg_param_spec_dress(const gchar *name, const gchar *nick, const gchar *blurb,
 541                      AdgDress dress, GParamFlags flags)
 542 {
 543     AdgParamSpecDress *fspec;
 544
 545     if (!_adg_dress_is_valid_with_log(dress))
 546         return NULL;
 547
 548     fspec = g_param_spec_internal(ADG_TYPE_PARAM_SPEC_DRESS,
 549                                   name, nick, blurb, flags);
 550     fspec->source_dress = dress;
 551
 552     return (GParamSpec *) fspec;
 553 }
 554
 555
 556 static GArray *
 557 _adg_array_singleton(void)
 558 {
 559     static GArray *array = NULL;
 560
 561     if (array == NULL) {
 562         const AdgDressPrivate data = { 0, };
 563
 564         array = g_array_new(FALSE, FALSE, sizeof(AdgDressPrivate));
 565
 566         /* Reserve the first item for the undefined dress */
 567         g_array_append_val(array, data);
 568     }
 569
 570     return array;
 571 }
 572
 573 static guint
 574 _adg_array_append(AdgDressPrivate *data)
 575 {
 576     return g_array_append_val(_adg_array_singleton(), *data)->len;
 577 }
 578
 579 static AdgDressPrivate *
 580 _adg_array_lookup(guint n)
 581 {
 582     return &g_array_index(_adg_array_singleton(), AdgDressPrivate, n);
 583 }
 584
 585 static guint
 586 _adg_array_len(void)
 587 {
 588     return _adg_array_singleton()->len;
 589 }