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 GSList * get_dependencies        (AdgModel       *model);
  72 static void     add_dependency          (AdgModel       *model,
  73                                          AdgEntity      *entity);
  74 static void     remove_dependency       (AdgModel       *model,
  75                                          AdgEntity      *entity);
  76 static void     changed                 (AdgModel       *model);
  77
  78 static guint signals[LAST_SIGNAL] = { 0 };
  79
  80
  81 G_DEFINE_ABSTRACT_TYPE(AdgModel, adg_model, G_TYPE_OBJECT);
  82
  83
  84 static void
  85 adg_model_class_init(AdgModelClass *klass)
  86 {
  87     GObjectClass *gobject_class;
  88     GParamSpec *param;
  89
  90     gobject_class = (GObjectClass *) klass;
  91
  92     g_type_class_add_private(klass, sizeof(AdgModelPrivate));
  93
  94     gobject_class->dispose = dispose;
  95     gobject_class->set_property = set_property;
  96
  97     klass->get_dependencies = get_dependencies;
  98     klass->add_dependency = add_dependency;
  99     klass->remove_dependency = remove_dependency;
 100     klass->clear = NULL;
 101     klass->changed = changed;
 102
 103     param = g_param_spec_object("dependency",
 104                                 P_("Dependency"),
 105                                 P_("Can be used to add a new dependency from this model (this entity will be invalidated on model changed)"),
 106                                 ADG_TYPE_ENTITY, G_PARAM_WRITABLE);
 107     g_object_class_install_property(gobject_class, PROP_DEPENDENCY, param);
 108
 109     /**
 110      * AdgModel::add-dependency:
 111      * @model: an #AdgModel
 112      * @entity: an #AdgEntity that depends on @model
 113      *
 114      * Adds @entity to @model. After that @entity will depend on @model,
 115      * that is #AdgModel::changed on @model will invalidate @entity.
 116      **/
 117     signals[ADD_DEPENDENCY] = g_signal_new("add-dependency",
 118                                            G_OBJECT_CLASS_TYPE(gobject_class),
 119                                            G_SIGNAL_RUN_FIRST,
 120                                            G_STRUCT_OFFSET(AdgModelClass, add_dependency),
 121                                            NULL, NULL,
 122                                            adg_marshal_VOID__OBJECT,
 123                                            G_TYPE_NONE, 1, ADG_TYPE_ENTITY);
 124
 125     /**
 126      * AdgModel::remove-dependency:
 127      * @model: an #AdgModel
 128      * @entity: the #AdgEntity that does not depend on @model anymore
 129      *
 130      * Removes the @entity from @model, that is @entity will not depend
 131      * on @model anymore.
 132      **/
 133     signals[REMOVE_DEPENDENCY] = g_signal_new("remove-dependency",
 134                                               G_OBJECT_CLASS_TYPE(gobject_class),
 135                                               G_SIGNAL_RUN_FIRST,
 136                                               G_STRUCT_OFFSET(AdgModelClass, remove_dependency),
 137                                               NULL, NULL,
 138                                               adg_marshal_VOID__OBJECT,
 139                                               G_TYPE_NONE, 1, ADG_TYPE_ENTITY);
 140
 141     /**
 142      * AdgModel::clear:
 143      * @model: an #AdgModel
 144      *
 145      * Removes any cached information from @model.
 146      **/
 147     signals[CLEAR] = g_signal_new("clear", ADG_TYPE_MODEL,
 148                                   G_SIGNAL_RUN_LAST|G_SIGNAL_NO_RECURSE,
 149                                   G_STRUCT_OFFSET(AdgModelClass, clear),
 150                                   NULL, NULL,
 151                                   adg_marshal_VOID__VOID,
 152                                   G_TYPE_NONE, 0);
 153
 154     /**
 155      * AdgModel::changed:
 156      * @model: an #AdgModel
 157      *
 158      * Notificates that the model has changed. By default, all the
 159      * dependent entities are invalidated.
 160      **/
 161     signals[CHANGED] = g_signal_new("changed", ADG_TYPE_MODEL,
 162                                      G_SIGNAL_RUN_LAST|G_SIGNAL_NO_RECURSE,
 163                                      G_STRUCT_OFFSET(AdgModelClass, changed),
 164                                      NULL, NULL,
 165                                      adg_marshal_VOID__VOID,
 166                                      G_TYPE_NONE, 0);
 167 }
 168
 169 static void
 170 adg_model_init(AdgModel *model)
 171 {
 172     AdgModelPrivate *data = G_TYPE_INSTANCE_GET_PRIVATE(model, ADG_TYPE_MODEL,
 173                                                         AdgModelPrivate);
 174
 175     data->dependencies = NULL;
 176
 177     model->data = data;
 178 }
 179
 180 static void
 181 dispose(GObject *object)
 182 {
 183     AdgModel *model;
 184     AdgModelPrivate *data;
 185
 186     model = (AdgModel *) object;
 187     data = model->data;
 188
 189     /* Remove all the dependencies from the model: this will emit
 190      * a "remove" signal for every dependency and will drop all the
 191      * references from those entities to this model */
 192     while (data->dependencies != NULL)
 193         adg_model_remove_dependency(model,
 194                                     (AdgEntity *) data->dependencies->data);
 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_get_dependencies:
 264  * @model: an #AdgModel
 265  *
 266  * Gets a list of entities dependent on @model.
 267  * This list must be freed with g_slist_free() when no longer user.
 268  *
 269  * Returns: a newly allocated #GSList or %NULL on error
 270  **/
 271 GSList *
 272 adg_model_get_dependencies(AdgModel *model)
 273 {
 274     g_return_val_if_fail(ADG_IS_MODEL(model), NULL);
 275
 276     return ADG_MODEL_GET_CLASS(model)->get_dependencies(model);
 277 }
 278
 279 /**
 280  * adg_model_foreach_dependency:
 281  * @model: an #AdgModel
 282  * @callback: a callback
 283  * @user_data: callback user data
 284  *
 285  * Invokes @callback on each entity linked to @model.
 286  * The callback should be declared as:
 287  *
 288  * |[
 289  * void callback(AdgEntity *entity, gpointer user_data);
 290  * ]|
 291  **/
 292 void
 293 adg_model_foreach_dependency(AdgModel *model, GCallback callback,
 294                              gpointer user_data)
 295 {
 296     GSList *dependencies;
 297
 298     g_return_if_fail(ADG_IS_MODEL(model));
 299     g_return_if_fail(callback != NULL);
 300
 301     dependencies = adg_model_get_dependencies(model);
 302
 303     while (dependencies) {
 304         if (dependencies->data)
 305             ((void (*) (gpointer, gpointer)) callback) (dependencies->data,
 306                                                         user_data);
 307
 308         dependencies = g_slist_delete_link(dependencies, dependencies);
 309     }
 310 }
 311
 312 /**
 313  * adg_model_clear:
 314  * @model: an #AdgModel
 315  *
 316  * <note><para>
 317  * This function is only useful in entity implementations.
 318  * </para></note>
 319  *
 320  * Emits the #AdgModel::clear signal on @model.
 321  **/
 322 void
 323 adg_model_clear(AdgModel *model)
 324 {
 325     g_return_if_fail(ADG_IS_MODEL(model));
 326
 327     g_signal_emit(model, signals[CLEAR], 0);
 328 }
 329
 330 /**
 331  * adg_model_changed:
 332  * @model: an #AdgModel
 333  *
 334  * <note><para>
 335  * This function is only useful in entity implementations.
 336  * </para></note>
 337  *
 338  * Emits the #AdgModel::changed signal on @model.
 339  **/
 340 void
 341 adg_model_changed(AdgModel *model)
 342 {
 343     g_return_if_fail(ADG_IS_MODEL(model));
 344
 345     g_signal_emit(model, signals[CHANGED], 0);
 346 }
 347
 348
 349 static void
 350 add_dependency(AdgModel *model, AdgEntity *entity)
 351 {
 352     AdgModelPrivate *data = model->data;
 353
 354     /* The prepend operation is more efficient */
 355     data->dependencies = g_slist_prepend(data->dependencies, entity);
 356
 357     g_object_ref(entity);
 358 }
 359
 360 static void
 361 remove_dependency(AdgModel *model, AdgEntity *entity)
 362 {
 363     AdgModelPrivate *data;
 364     GSList *node;
 365
 366     data = model->data;
 367     node = g_slist_find(data->dependencies, entity);
 368
 369     if (node == NULL) {
 370         g_warning("Attempting to remove an entity with type %s from a "
 371                   "model of type %s, but the entity is not present.",
 372                   g_type_name(G_OBJECT_TYPE(entity)),
 373                   g_type_name(G_OBJECT_TYPE(model)));
 374         return;
 375     }
 376
 377     data->dependencies = g_slist_delete_link(data->dependencies, node);
 378     g_object_unref(entity);
 379 }
 380
 381 static GSList *
 382 get_dependencies(AdgModel *model)
 383 {
 384     AdgModelPrivate *data = model->data;
 385
 386     /* The NULL case is yet managed by GLib */
 387     return g_slist_copy(data->dependencies);
 388 }
 389
 390 static void
 391 changed(AdgModel *model)
 392 {
 393     /* Invalidate all the entities dependent on this model */
 394     adg_model_foreach_dependency(model,
 395                                  G_CALLBACK(adg_entity_invalidate), NULL);
 396 }