adg/adg-model.c

   1 /* ADG - Automatic Drawing Generation
   2  * Copyright (C) 2007,2008,2009,2010  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-model
  23  * @short_description: The base class of the ADG model infrastructure
  24  *
  25  * A model is a conceptual representation of something. From an ADG
  26  * user point of view, it is a collection of data and rules that
  27  * defines how an object should be represented on a drawing.
  28  *
  29  * Because #AdgModel instances are only a conceptual idea, they are
  30  * not renderable (that is, #AdgModel is not derived from #AdgEntity).
  31  * Instead, it must be passed as subject to entities such as #AdgStroke
  32  * or #AdgHatch.
  33  **/
  34
  35 /**
  36  * AdgModel:
  37  *
  38  * All fields are private and should not be used directly.
  39  * Use its public methods instead.
  40  **/
  41
  42 /**
  43  * AdgNamedPairCallback:
  44  * @name: an arbitrary name
  45  * @pair: an #AdgPair
  46  * @user_data: a general purpose pointer
  47  *
  48  * Callback used by adg_model_foreach_named_pair().
  49  **/
  50
  51
  52 #include "adg-internal.h"
  53 #include "adg-model.h"
  54 #include "adg-model-private.h"
  55 #include "adg-marshal.h"
  56
  57 #define PARENT_OBJECT_CLASS  ((GObjectClass *) adg_model_parent_class)
  58
  59
  60 enum {
  61     PROP_0,
  62     PROP_DEPENDENCY
  63 };
  64
  65 enum {
  66     ADD_DEPENDENCY,
  67     REMOVE_DEPENDENCY,
  68     SET_NAMED_PAIR,
  69     CLEAR,
  70     CHANGED,
  71     LAST_SIGNAL
  72 };
  73
  74
  75 static void     dispose                 (GObject        *object);
  76 static void     set_property            (GObject        *object,
  77                                          guint           prop_id,
  78                                          const GValue   *value,
  79                                          GParamSpec     *pspec);
  80 static void     add_dependency          (AdgModel       *model,
  81                                          AdgEntity      *entity);
  82 static void     remove_dependency       (AdgModel       *model,
  83                                          AdgEntity      *entity);
  84 static const AdgPair *
  85                 named_pair              (AdgModel       *model,
  86                                          const gchar    *name);
  87 static void     set_named_pair          (AdgModel       *model,
  88                                          const gchar    *name,
  89                                          const AdgPair  *pair);
  90 static void     changed                 (AdgModel       *model);
  91
  92 static guint signals[LAST_SIGNAL] = { 0 };
  93
  94
  95 G_DEFINE_ABSTRACT_TYPE(AdgModel, adg_model, G_TYPE_OBJECT);
  96
  97
  98 static void
  99 adg_model_class_init(AdgModelClass *klass)
 100 {
 101     GObjectClass *gobject_class;
 102     GParamSpec *param;
 103
 104     gobject_class = (GObjectClass *) klass;
 105
 106     g_type_class_add_private(klass, sizeof(AdgModelPrivate));
 107
 108     gobject_class->dispose = dispose;
 109     gobject_class->set_property = set_property;
 110
 111     klass->add_dependency = add_dependency;
 112     klass->remove_dependency = remove_dependency;
 113     klass->named_pair = named_pair;
 114     klass->set_named_pair = set_named_pair;
 115     klass->clear = NULL;
 116     klass->changed = changed;
 117
 118     param = g_param_spec_object("dependency",
 119                                 P_("Dependency"),
 120                                 P_("Can be used to add a new dependency from this model (this entity will be invalidated on model changed)"),
 121                                 ADG_TYPE_ENTITY,
 122                                 G_PARAM_WRITABLE);
 123     g_object_class_install_property(gobject_class, PROP_DEPENDENCY, param);
 124
 125     /**
 126      * AdgModel::add-dependency:
 127      * @model: an #AdgModel
 128      * @entity: an #AdgEntity that depends on @model
 129      *
 130      * Adds @entity to @model. After that @entity will depend on @model,
 131      * that is #AdgModel::changed on @model will invalidate @entity.
 132      **/
 133     signals[ADD_DEPENDENCY] = g_signal_new("add-dependency",
 134                                            G_OBJECT_CLASS_TYPE(gobject_class),
 135                                            G_SIGNAL_RUN_FIRST,
 136                                            G_STRUCT_OFFSET(AdgModelClass, add_dependency),
 137                                            NULL, NULL,
 138                                            adg_marshal_VOID__OBJECT,
 139                                            G_TYPE_NONE, 1, ADG_TYPE_ENTITY);
 140
 141     /**
 142      * AdgModel::remove-dependency:
 143      * @model: an #AdgModel
 144      * @entity: the #AdgEntity that does not depend on @model anymore
 145      *
 146      * Removes the @entity from @model, that is @entity will not depend
 147      * on @model anymore.
 148      **/
 149     signals[REMOVE_DEPENDENCY] = g_signal_new("remove-dependency",
 150                                               G_OBJECT_CLASS_TYPE(gobject_class),
 151                                               G_SIGNAL_RUN_FIRST,
 152                                               G_STRUCT_OFFSET(AdgModelClass, remove_dependency),
 153                                               NULL, NULL,
 154                                               adg_marshal_VOID__OBJECT,
 155                                               G_TYPE_NONE, 1, ADG_TYPE_ENTITY);
 156
 157     /**
 158      * AdgModel::set-named-pair:
 159      * @model: an #AdgModel
 160      * @name: an arbitrary name
 161      * @pair: an #AdgPair
 162      *
 163      * Adds, updates or deletes a named pair, accordling to the given
 164      * parameters.
 165      *
 166      * If @pair is %NULL, the @name named pair is searched and deleted.
 167      * If it is not found, a warning is raised.
 168      *
 169      * Otherwise, the @name named pair is searched: if it is found,
 170      * its data are updated with @pair. If it is not found, a new
 171      * named pair is created using @name and @pair.
 172      **/
 173     signals[SET_NAMED_PAIR] = g_signal_new("set-named-pair",
 174                                            G_OBJECT_CLASS_TYPE(gobject_class),
 175                                            G_SIGNAL_RUN_FIRST,
 176                                            G_STRUCT_OFFSET(AdgModelClass, set_named_pair),
 177                                            NULL, NULL,
 178                                            adg_marshal_VOID__STRING_POINTER,
 179                                            G_TYPE_NONE, 2,
 180                                            G_TYPE_STRING, G_TYPE_POINTER);
 181
 182     /**
 183      * AdgModel::clear:
 184      * @model: an #AdgModel
 185      *
 186      * Removes any cached information from @model.
 187      **/
 188     signals[CLEAR] = g_signal_new("clear", ADG_TYPE_MODEL,
 189                                   G_SIGNAL_RUN_LAST|G_SIGNAL_NO_RECURSE,
 190                                   G_STRUCT_OFFSET(AdgModelClass, clear),
 191                                   NULL, NULL,
 192                                   adg_marshal_VOID__VOID,
 193                                   G_TYPE_NONE, 0);
 194
 195     /**
 196      * AdgModel::changed:
 197      * @model: an #AdgModel
 198      *
 199      * Notificates that the model has changed. By default, all the
 200      * dependent entities are invalidated.
 201      **/
 202     signals[CHANGED] = g_signal_new("changed", ADG_TYPE_MODEL,
 203                                      G_SIGNAL_RUN_LAST|G_SIGNAL_NO_RECURSE,
 204                                      G_STRUCT_OFFSET(AdgModelClass, changed),
 205                                      NULL, NULL,
 206                                      adg_marshal_VOID__VOID,
 207                                      G_TYPE_NONE, 0);
 208 }
 209
 210 static void
 211 adg_model_init(AdgModel *model)
 212 {
 213     AdgModelPrivate *data = G_TYPE_INSTANCE_GET_PRIVATE(model, ADG_TYPE_MODEL,
 214                                                         AdgModelPrivate);
 215
 216     data->dependencies = NULL;
 217
 218     model->data = data;
 219 }
 220
 221 static void
 222 dispose(GObject *object)
 223 {
 224     AdgModel *model;
 225     AdgModelPrivate *data;
 226     AdgEntity *entity;
 227
 228     model = (AdgModel *) object;
 229     data = model->data;
 230
 231     /* Remove all the dependencies from the model: this will emit
 232      * a "remove" signal for every dependency and will drop all the
 233      * references from those entities to this model */
 234     while (data->dependencies != NULL) {
 235         entity = (AdgEntity *) data->dependencies->data;
 236         adg_model_remove_dependency(model, entity);
 237     }
 238
 239     if (PARENT_OBJECT_CLASS->dispose)
 240         PARENT_OBJECT_CLASS->dispose(object);
 241 }
 242
 243 static void
 244 set_property(GObject *object,
 245              guint prop_id, const GValue *value, GParamSpec *pspec)
 246 {
 247     AdgModel *model = (AdgModel *) object;
 248
 249     switch (prop_id) {
 250     case PROP_DEPENDENCY:
 251         adg_model_add_dependency(model, g_value_get_object(value));
 252         break;
 253     default:
 254         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 255     }
 256 }
 257
 258
 259 /**
 260  * adg_model_add_dependency:
 261  * @model: an #AdgModel
 262  * @entity: an #AdgEntity
 263  *
 264  * <note><para>
 265  * This function is only useful in entity implementations.
 266  * </para></note>
 267  *
 268  * Emits a #AdgModel::add-dependency signal on @model passing @entity
 269  * as argument. This will add a reference to @entity owned by @model.
 270  **/
 271 void
 272 adg_model_add_dependency(AdgModel *model, AdgEntity *entity)
 273 {
 274     g_return_if_fail(ADG_IS_MODEL(model));
 275     g_return_if_fail(ADG_IS_ENTITY(entity));
 276
 277     g_signal_emit(model, signals[ADD_DEPENDENCY], 0, entity);
 278 }
 279
 280 /**
 281  * adg_model_remove_dependency:
 282  * @model: an #AdgModel
 283  * @entity: an #AdgEntity
 284  *
 285  * <note><para>
 286  * This function is only useful in entity implementations.
 287  * </para></note>
 288  *
 289  * Emits a #AdgModel::remove-dependency signal on @model passing
 290  * @entity as argument. @entity must be inside @model.
 291  *
 292  * Note that @model will own a reference to @entity and it
 293  * may be the last reference held: this means removing an entity
 294  * from the model can destroy it.
 295  **/
 296 void
 297 adg_model_remove_dependency(AdgModel *model, AdgEntity *entity)
 298 {
 299     g_return_if_fail(ADG_IS_MODEL(model));
 300     g_return_if_fail(ADG_IS_ENTITY(entity));
 301
 302     g_signal_emit(model, signals[REMOVE_DEPENDENCY], 0, entity);
 303 }
 304
 305 /**
 306  * adg_model_get_dependencies:
 307  * @model: an #AdgModel
 308  *
 309  * Gets the list of entities dependending on @model. This list
 310  * is owned by @model and must not be modified or freed.
 311  *
 312  * Returns: a #GSList of dependencies or %NULL on error
 313  **/
 314 const GSList *
 315 adg_model_get_dependencies(AdgModel *model)
 316 {
 317     AdgModelPrivate *data;
 318
 319     g_return_val_if_fail(ADG_IS_MODEL(model), NULL);
 320
 321     data = model->data;
 322
 323     return data->dependencies;
 324 }
 325
 326 /**
 327  * adg_model_foreach_dependency:
 328  * @model: an #AdgModel
 329  * @callback: the entity callback
 330  * @user_data: general purpose user data passed "as is" to @callback
 331  *
 332  * Invokes @callback on each entity linked to @model.
 333  **/
 334 void
 335 adg_model_foreach_dependency(AdgModel *model, AdgEntityCallback callback,
 336                              gpointer user_data)
 337 {
 338     AdgModelPrivate *data;
 339     GSList *dependency;
 340     AdgEntity *entity;
 341
 342     g_return_if_fail(ADG_IS_MODEL(model));
 343     g_return_if_fail(callback != NULL);
 344
 345     data = model->data;
 346     dependency = data->dependencies;
 347
 348     while (dependency != NULL) {
 349         entity = dependency->data;
 350
 351         if (entity != NULL && ADG_IS_ENTITY(entity))
 352             callback(entity, user_data);
 353
 354         dependency = dependency->next;
 355     }
 356 }
 357
 358 /**
 359  * adg_model_set_named_pair:
 360  * @model: an #AdgModel
 361  * @name: the name to associate to the pair
 362  * @pair: the #AdgPair
 363  *
 364  * <note><para>
 365  * This function is only useful in model definitions, such as
 366  * inside an #AdgTrailCallback function or while constructing
 367  * an #AdgPath instance.
 368  * </para></note>
 369  *
 370  * Emits a #AdgModel::set-named-pair signal on @model passing
 371  * @name and @pair as arguments.
 372  **/
 373 void
 374 adg_model_set_named_pair(AdgModel *model, const gchar *name,
 375                          const AdgPair *pair)
 376 {
 377     g_return_if_fail(ADG_IS_MODEL(model));
 378     g_return_if_fail(name != NULL);
 379
 380     g_signal_emit(model, signals[SET_NAMED_PAIR], 0, name, pair);
 381 }
 382
 383 /**
 384  * adg_model_get_named_pair:
 385  * @model: an #AdgModel
 386  * @name: the name of the pair to get
 387  *
 388  * Gets the @name named pair associated to @model. The returned
 389  * pair is owned by @model and must not be modified or freed.
 390  *
 391  * Returns: the requested #AdgPair or %NULL if not found
 392  **/
 393 const AdgPair *
 394 adg_model_get_named_pair(AdgModel *model, const gchar *name)
 395 {
 396     AdgModelClass *klass;
 397
 398     g_return_val_if_fail(ADG_IS_MODEL(model), NULL);
 399     g_return_val_if_fail(name != NULL, NULL);
 400
 401     klass = ADG_MODEL_GET_CLASS(model);
 402
 403     if (klass->named_pair == NULL)
 404         return NULL;
 405
 406     return klass->named_pair(model, name);
 407 }
 408
 409 /**
 410  * adg_model_foreach_named_pair:
 411  * @model: an #AdgModel
 412  * @callback: the named pair callback
 413  * @user_data: general purpose user data passed "as is" to @callback
 414  *
 415  * Invokes @callback for each named pair set on @model. This can
 416  * be used, for example, to retrieve all the named pairs of a @model
 417  * or to duplicate a transformed version of every named pair.
 418  **/
 419 void
 420 adg_model_foreach_named_pair(AdgModel *model, AdgNamedPairCallback callback,
 421                              gpointer user_data)
 422 {
 423     AdgModelPrivate *data;
 424
 425     g_return_if_fail(ADG_IS_MODEL(model));
 426     g_return_if_fail(callback != NULL);
 427
 428     data = model->data;
 429
 430     if (data->named_pairs == NULL)
 431         return;
 432
 433     g_hash_table_foreach(data->named_pairs, (GHFunc) callback, user_data);
 434 }
 435
 436 /**
 437  * adg_model_clear:
 438  * @model: an #AdgModel
 439  *
 440  * <note><para>
 441  * This function is only useful in entity implementations.
 442  * </para></note>
 443  *
 444  * Emits the #AdgModel::clear signal on @model.
 445  **/
 446 void
 447 adg_model_clear(AdgModel *model)
 448 {
 449     g_return_if_fail(ADG_IS_MODEL(model));
 450
 451     g_signal_emit(model, signals[CLEAR], 0);
 452 }
 453
 454 /**
 455  * adg_model_changed:
 456  * @model: an #AdgModel
 457  *
 458  * <note><para>
 459  * This function is only useful in entity implementations.
 460  * </para></note>
 461  *
 462  * Emits the #AdgModel::changed signal on @model.
 463  **/
 464 void
 465 adg_model_changed(AdgModel *model)
 466 {
 467     g_return_if_fail(ADG_IS_MODEL(model));
 468
 469     g_signal_emit(model, signals[CHANGED], 0);
 470 }
 471
 472
 473 static void
 474 add_dependency(AdgModel *model, AdgEntity *entity)
 475 {
 476     AdgModelPrivate *data = model->data;
 477
 478     /* The prepend operation is more efficient */
 479     data->dependencies = g_slist_prepend(data->dependencies, entity);
 480
 481     g_object_ref(entity);
 482 }
 483
 484 static void
 485 remove_dependency(AdgModel *model, AdgEntity *entity)
 486 {
 487     AdgModelPrivate *data;
 488     GSList *node;
 489
 490     data = model->data;
 491     node = g_slist_find(data->dependencies, entity);
 492
 493     if (node == NULL) {
 494         g_warning("%s: attempting to remove an entity with type %s "
 495                   "from a model of type %s, but the entity is not present.",
 496                   G_STRLOC,
 497                   g_type_name(G_OBJECT_TYPE(entity)),
 498                   g_type_name(G_OBJECT_TYPE(model)));
 499         return;
 500     }
 501
 502     data->dependencies = g_slist_delete_link(data->dependencies, node);
 503     g_object_unref(entity);
 504 }
 505
 506 static void
 507 set_named_pair(AdgModel *model, const gchar *name, const AdgPair *pair)
 508 {
 509     AdgModelPrivate *data;
 510     GHashTable **hash;
 511     gchar *key;
 512     AdgPair *value;
 513
 514     data = model->data;
 515     hash = &data->named_pairs;
 516
 517     if (pair == NULL) {
 518         /* Delete mode: raise a warning if @name is not found */
 519         if (*hash == NULL || !g_hash_table_remove(*hash, name))
 520             g_warning("%s: attempting to remove inexistent `%s' named pair",
 521                       G_STRLOC, name);
 522
 523         return;
 524     }
 525
 526     /* Insert/update mode */
 527     key = g_strdup(name);
 528     value = adg_pair_dup(pair);
 529
 530     if (*hash == NULL)
 531         *hash = g_hash_table_new_full(g_str_hash, g_str_equal, g_free, g_free);
 532
 533     g_hash_table_insert(*hash, key, value);
 534 }
 535
 536 static const AdgPair *
 537 named_pair(AdgModel *model, const gchar *name)
 538 {
 539     AdgModelPrivate *data = model->data;
 540
 541     if (data->named_pairs == NULL)
 542         return NULL;
 543
 544     return g_hash_table_lookup(data->named_pairs, name);
 545 }
 546
 547 static void
 548 changed(AdgModel *model)
 549 {
 550     /* Invalidate all the entities dependent on this model */
 551     adg_model_foreach_dependency(model,
 552                                  (AdgEntityCallback) adg_entity_invalidate,
 553                                  NULL);
 554 }