adg/adg-model.c

   1 /* ADG - Automatic Drawing Generation
   2  * Copyright (C) 2007,2008,2009 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 #include "adg-model.h"
  44 #include "adg-model-private.h"
  45 #include "adg-marshal.h"
  46 #include "adg-intl.h"
  47
  48 #define PARENT_OBJECT_CLASS  ((GObjectClass *) adg_model_parent_class)
  49
  50
  51 enum {
  52     PROP_0,
  53     PROP_DEPENDENCY
  54 };
  55
  56 enum {
  57     ADD_DEPENDENCY,
  58     REMOVE_DEPENDENCY,
  59     CLEAR,
  60     CHANGED,
  61     LAST_SIGNAL
  62 };
  63
  64
  65 static void     dispose                 (GObject        *object);
  66 static void     set_property            (GObject        *object,
  67                                          guint           prop_id,
  68                                          const GValue   *value,
  69                                          GParamSpec     *pspec);
  70
  71 static void     add_dependency          (AdgModel       *model,
  72                                          AdgEntity      *entity);
  73 static void     remove_dependency       (AdgModel       *model,
  74                                          AdgEntity      *entity);
  75 static void     changed                 (AdgModel       *model);
  76
  77 static guint signals[LAST_SIGNAL] = { 0 };
  78
  79
  80 G_DEFINE_ABSTRACT_TYPE(AdgModel, adg_model, G_TYPE_OBJECT);
  81
  82
  83 static void
  84 adg_model_class_init(AdgModelClass *klass)
  85 {
  86     GObjectClass *gobject_class;
  87     GParamSpec *param;
  88
  89     gobject_class = (GObjectClass *) klass;
  90
  91     g_type_class_add_private(klass, sizeof(AdgModelPrivate));
  92
  93     gobject_class->dispose = dispose;
  94     gobject_class->set_property = set_property;
  95
  96     klass->add_dependency = add_dependency;
  97     klass->remove_dependency = remove_dependency;
  98     klass->clear = NULL;
  99     klass->changed = changed;
 100
 101     param = g_param_spec_object("dependency",
 102                                 P_("Dependency"),
 103                                 P_("Can be used to add a new dependency from this model (this entity will be invalidated on model changed)"),
 104                                 ADG_TYPE_ENTITY, G_PARAM_WRITABLE);
 105     g_object_class_install_property(gobject_class, PROP_DEPENDENCY, param);
 106
 107     /**
 108      * AdgModel::add-dependency:
 109      * @model: an #AdgModel
 110      * @entity: an #AdgEntity that depends on @model
 111      *
 112      * Adds @entity to @model. After that @entity will depend on @model,
 113      * that is #AdgModel::changed on @model will invalidate @entity.
 114      **/
 115     signals[ADD_DEPENDENCY] = g_signal_new("add-dependency",
 116                                            G_OBJECT_CLASS_TYPE(gobject_class),
 117                                            G_SIGNAL_RUN_FIRST,
 118                                            G_STRUCT_OFFSET(AdgModelClass, add_dependency),
 119                                            NULL, NULL,
 120                                            adg_marshal_VOID__OBJECT,
 121                                            G_TYPE_NONE, 1, ADG_TYPE_ENTITY);
 122
 123     /**
 124      * AdgModel::remove-dependency:
 125      * @model: an #AdgModel
 126      * @entity: the #AdgEntity that does not depend on @model anymore
 127      *
 128      * Removes the @entity from @model, that is @entity will not depend
 129      * on @model anymore.
 130      **/
 131     signals[REMOVE_DEPENDENCY] = g_signal_new("remove-dependency",
 132                                               G_OBJECT_CLASS_TYPE(gobject_class),
 133                                               G_SIGNAL_RUN_FIRST,
 134                                               G_STRUCT_OFFSET(AdgModelClass, remove_dependency),
 135                                               NULL, NULL,
 136                                               adg_marshal_VOID__OBJECT,
 137                                               G_TYPE_NONE, 1, ADG_TYPE_ENTITY);
 138
 139     /**
 140      * AdgModel::clear:
 141      * @model: an #AdgModel
 142      *
 143      * Removes any cached information from @model.
 144      **/
 145     signals[CLEAR] = g_signal_new("clear", ADG_TYPE_MODEL,
 146                                   G_SIGNAL_RUN_LAST|G_SIGNAL_NO_RECURSE,
 147                                   G_STRUCT_OFFSET(AdgModelClass, clear),
 148                                   NULL, NULL,
 149                                   adg_marshal_VOID__VOID,
 150                                   G_TYPE_NONE, 0);
 151
 152     /**
 153      * AdgModel::changed:
 154      * @model: an #AdgModel
 155      *
 156      * Notificates that the model has changed. By default, all the
 157      * dependent entities are invalidated.
 158      **/
 159     signals[CHANGED] = g_signal_new("changed", ADG_TYPE_MODEL,
 160                                      G_SIGNAL_RUN_LAST|G_SIGNAL_NO_RECURSE,
 161                                      G_STRUCT_OFFSET(AdgModelClass, changed),
 162                                      NULL, NULL,
 163                                      adg_marshal_VOID__VOID,
 164                                      G_TYPE_NONE, 0);
 165 }
 166
 167 static void
 168 adg_model_init(AdgModel *model)
 169 {
 170     AdgModelPrivate *data = G_TYPE_INSTANCE_GET_PRIVATE(model, ADG_TYPE_MODEL,
 171                                                         AdgModelPrivate);
 172
 173     data->dependencies = NULL;
 174
 175     model->data = data;
 176 }
 177
 178 static void
 179 dispose(GObject *object)
 180 {
 181     AdgModel *model;
 182     AdgModelPrivate *data;
 183     AdgEntity *entity;
 184
 185     model = (AdgModel *) object;
 186     data = model->data;
 187
 188     /* Remove all the dependencies from the model: this will emit
 189      * a "remove" signal for every dependency and will drop all the
 190      * references from those entities to this model */
 191     while (data->dependencies != NULL) {
 192         entity = (AdgEntity *) data->dependencies->data;
 193         adg_model_remove_dependency(model, entity);
 194     }
 195
 196     if (PARENT_OBJECT_CLASS->dispose != NULL)
 197         PARENT_OBJECT_CLASS->dispose(object);
 198 }
 199
 200 static void
 201 set_property(GObject *object,
 202              guint prop_id, const GValue *value, GParamSpec *pspec)
 203 {
 204     AdgModel *model = (AdgModel *) object;
 205
 206     switch (prop_id) {
 207     case PROP_DEPENDENCY:
 208         adg_model_add_dependency(model, g_value_get_object(value));
 209         break;
 210     default:
 211         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 212     }
 213 }
 214
 215
 216 /**
 217  * adg_model_add_dependency:
 218  * @model: an #AdgModel
 219  * @entity: an #AdgEntity
 220  *
 221  * <note><para>
 222  * This function is only useful in entity implementations.
 223  * </para></note>
 224  *
 225  * Emits a #AdgModel::add-dependency signal on @model passing @entity
 226  * as argument. This will add a reference to @entity owned by @model.
 227  **/
 228 void
 229 adg_model_add_dependency(AdgModel *model, AdgEntity *entity)
 230 {
 231     g_return_if_fail(ADG_IS_MODEL(model));
 232     g_return_if_fail(ADG_IS_ENTITY(entity));
 233
 234     g_signal_emit(model, signals[ADD_DEPENDENCY], 0, entity);
 235 }
 236
 237 /**
 238  * adg_model_remove_dependency:
 239  * @model: an #AdgModel
 240  * @entity: an #AdgEntity
 241  *
 242  * <note><para>
 243  * This function is only useful in entity implementations.
 244  * </para></note>
 245  *
 246  * Emits a #AdgModel::remove-dependency signal on @model passing
 247  * @entity as argument. @entity must be inside @model.
 248  *
 249  * Note that @model will own a reference to @entity and it
 250  * may be the last reference held: this means removing an entity
 251  * from the model can destroy it.
 252  **/
 253 void
 254 adg_model_remove_dependency(AdgModel *model, AdgEntity *entity)
 255 {
 256     g_return_if_fail(ADG_IS_MODEL(model));
 257     g_return_if_fail(ADG_IS_ENTITY(entity));
 258
 259     g_signal_emit(model, signals[REMOVE_DEPENDENCY], 0, entity);
 260 }
 261
 262 /**
 263  * adg_model_dependencies:
 264  * @model: an #AdgModel
 265  *
 266  * Gets the list of entities dependending on @model. This list
 267  * is owned by @model and must not be modified or freed.
 268  *
 269  * Returns: a #GSList of dependencies or %NULL on error
 270  **/
 271 const GSList *
 272 adg_model_dependencies(AdgModel *model)
 273 {
 274     AdgModelPrivate *data;
 275
 276     g_return_val_if_fail(ADG_IS_MODEL(model), NULL);
 277
 278     data = model->data;
 279
 280     return data->dependencies;
 281 }
 282
 283 /**
 284  * adg_model_foreach_dependency:
 285  * @model: an #AdgModel
 286  * @callback: the entity callback
 287  * @user_data: callback general purpose user data
 288  *
 289  * Invokes @callback on each entity linked to @model.
 290  **/
 291 void
 292 adg_model_foreach_dependency(AdgModel *model, AdgEntityCallback callback,
 293                              gpointer user_data)
 294 {
 295     AdgModelPrivate *data;
 296     GSList *dependency;
 297     AdgEntity *entity;
 298
 299     g_return_if_fail(ADG_IS_MODEL(model));
 300     g_return_if_fail(callback != NULL);
 301
 302     data = model->data;
 303     dependency = data->dependencies;
 304
 305     while (dependency != NULL) {
 306         entity = dependency->data;
 307
 308         if (entity != NULL && ADG_IS_ENTITY(entity))
 309             callback(entity, user_data);
 310
 311         dependency = dependency->next;
 312     }
 313 }
 314
 315 /**
 316  * adg_model_clear:
 317  * @model: an #AdgModel
 318  *
 319  * <note><para>
 320  * This function is only useful in entity implementations.
 321  * </para></note>
 322  *
 323  * Emits the #AdgModel::clear signal on @model.
 324  **/
 325 void
 326 adg_model_clear(AdgModel *model)
 327 {
 328     g_return_if_fail(ADG_IS_MODEL(model));
 329
 330     g_signal_emit(model, signals[CLEAR], 0);
 331 }
 332
 333 /**
 334  * adg_model_changed:
 335  * @model: an #AdgModel
 336  *
 337  * <note><para>
 338  * This function is only useful in entity implementations.
 339  * </para></note>
 340  *
 341  * Emits the #AdgModel::changed signal on @model.
 342  **/
 343 void
 344 adg_model_changed(AdgModel *model)
 345 {
 346     g_return_if_fail(ADG_IS_MODEL(model));
 347
 348     g_signal_emit(model, signals[CHANGED], 0);
 349 }
 350
 351
 352 static void
 353 add_dependency(AdgModel *model, AdgEntity *entity)
 354 {
 355     AdgModelPrivate *data = model->data;
 356
 357     /* The prepend operation is more efficient */
 358     data->dependencies = g_slist_prepend(data->dependencies, entity);
 359
 360     g_object_ref(entity);
 361 }
 362
 363 static void
 364 remove_dependency(AdgModel *model, AdgEntity *entity)
 365 {
 366     AdgModelPrivate *data;
 367     GSList *node;
 368
 369     data = model->data;
 370     node = g_slist_find(data->dependencies, entity);
 371
 372     if (node == NULL) {
 373         g_warning("Attempting to remove an entity with type %s from a "
 374                   "model of type %s, but the entity is not present.",
 375                   g_type_name(G_OBJECT_TYPE(entity)),
 376                   g_type_name(G_OBJECT_TYPE(model)));
 377         return;
 378     }
 379
 380     data->dependencies = g_slist_delete_link(data->dependencies, node);
 381     g_object_unref(entity);
 382 }
 383
 384 static void
 385 changed(AdgModel *model)
 386 {
 387     /* Invalidate all the entities dependent on this model */
 388     adg_model_foreach_dependency(model,
 389                                  (AdgEntityCallback) adg_entity_invalidate,
 390                                  NULL);
 391 }