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-intl.h"
  46
  47
  48 enum {
  49     PROP_0
  50 };
  51
  52 enum {
  53     CHANGED,
  54     LAST_SIGNAL
  55 };
  56
  57
  58 static void     get_property            (GObject        *object,
  59                                          guint           prop_id,
  60                                          GValue         *value,
  61                                          GParamSpec     *pspec);
  62 static void     set_property            (GObject        *object,
  63                                          guint           prop_id,
  64                                          const GValue   *value,
  65                                          GParamSpec     *pspec);
  66 static void     changed                 (AdgModel       *model);
  67
  68 static guint signals[LAST_SIGNAL] = { 0 };
  69
  70
  71 G_DEFINE_ABSTRACT_TYPE(AdgModel, adg_model, G_TYPE_OBJECT);
  72
  73
  74 static void
  75 adg_model_class_init(AdgModelClass *klass)
  76 {
  77     GObjectClass *gobject_class;
  78
  79     gobject_class = (GObjectClass *) klass;
  80
  81     g_type_class_add_private(klass, sizeof(AdgModelPrivate));
  82
  83     gobject_class->get_property = get_property;
  84     gobject_class->set_property = set_property;
  85
  86     klass->changed = changed;
  87
  88     /**
  89      * AdgModel::changed:
  90      * @model: an #AdgModel
  91      *
  92      * Notificates that the model has changed. By default, the model
  93      * cache is invalidated.
  94      **/
  95     signals[CHANGED] = g_signal_new("changed", ADG_TYPE_MODEL,
  96                                      G_SIGNAL_RUN_LAST|G_SIGNAL_NO_RECURSE,
  97                                      G_STRUCT_OFFSET(AdgModelClass, changed),
  98                                      NULL, NULL,
  99                                      g_cclosure_marshal_VOID__VOID,
 100                                      G_TYPE_NONE, 0);
 101 }
 102
 103 static void
 104 adg_model_init(AdgModel *model)
 105 {
 106     AdgModelPrivate *data = G_TYPE_INSTANCE_GET_PRIVATE(model, ADG_TYPE_MODEL,
 107                                                         AdgModelPrivate);
 108     model->data = data;
 109 }
 110
 111 static void
 112 get_property(GObject *object,
 113              guint prop_id, GValue *value, GParamSpec *pspec)
 114 {
 115     /* TODO: this is only a placeholder */
 116
 117     switch (prop_id) {
 118     default:
 119         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 120         break;
 121     }
 122 }
 123
 124 static void
 125 set_property(GObject *object,
 126              guint prop_id, const GValue *value, GParamSpec *pspec)
 127 {
 128     /* TODO: this is only a placeholder */
 129
 130     switch (prop_id) {
 131     default:
 132         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 133         break;
 134     }
 135 }
 136
 137
 138 /**
 139  * adg_model_changed:
 140  * @model: an #AdgModel
 141  *
 142  * Emits the "changed" signal on @model.
 143  *
 144  * This function is only useful in model implementations.
 145  */
 146 void
 147 adg_model_changed(AdgModel *model)
 148 {
 149     g_return_if_fail(ADG_IS_MODEL(model));
 150
 151     g_signal_emit(model, signals[CHANGED], 0);
 152 }
 153
 154
 155 static void
 156 changed(AdgModel *model)
 157 {
 158 }