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:model
  23  * @title: AdgModel
  24  * @short_description: The base class of the ADG model infrastructure
  25  *
  26  * A model is a conceptual representation of something. From an ADG
  27  * user point of view, it is a collection of data and rules that
  28  * defines how an object should be represented on a drawing.
  29  *
  30  * Because #AdgModel instances are only a conceptual idea, they are
  31  * not renderable (that is, #AdgModel is not derived from #AdgEntity).
  32  * Instead, it must be passed as subject to entities such as AdgStroke
  33  * or AdgHatch.
  34  **/
  35
  36 /**
  37  * AdgModel:
  38  *
  39  * All fields are private and should not be used directly.
  40  * Use its public methods instead.
  41  **/
  42
  43
  44 #include "adg-model.h"
  45 #include "adg-model-private.h"
  46 #include "adg-intl.h"
  47
  48
  49 enum {
  50     PROP_0
  51 };
  52
  53 enum {
  54     CHANGED,
  55     LAST_SIGNAL
  56 };
  57
  58
  59 static void     get_property            (GObject        *object,
  60                                          guint           prop_id,
  61                                          GValue         *value,
  62                                          GParamSpec     *pspec);
  63 static void     set_property            (GObject        *object,
  64                                          guint           prop_id,
  65                                          const GValue   *value,
  66                                          GParamSpec     *pspec);
  67 static void     changed                 (AdgModel       *model);
  68
  69 static guint signals[LAST_SIGNAL] = { 0 };
  70
  71
  72 G_DEFINE_ABSTRACT_TYPE(AdgModel, adg_model, G_TYPE_OBJECT);
  73
  74
  75 static void
  76 adg_model_class_init(AdgModelClass *klass)
  77 {
  78     GObjectClass *gobject_class;
  79
  80     gobject_class = (GObjectClass *) klass;
  81
  82     g_type_class_add_private(klass, sizeof(AdgModelPrivate));
  83
  84     gobject_class->get_property = get_property;
  85     gobject_class->set_property = set_property;
  86
  87     klass->changed = changed;
  88
  89     /**
  90      * AdgModel::changed:
  91      * @model: an #AdgModel
  92      *
  93      * Notificates that the model has changed. By default, the model
  94      * cache is invalidated.
  95      **/
  96     signals[CHANGED] = g_signal_new("changed", ADG_TYPE_MODEL,
  97                                      G_SIGNAL_RUN_LAST|G_SIGNAL_NO_RECURSE,
  98                                      G_STRUCT_OFFSET(AdgModelClass, changed),
  99                                      NULL, NULL,
 100                                      g_cclosure_marshal_VOID__VOID,
 101                                      G_TYPE_NONE, 0);
 102 }
 103
 104 static void
 105 adg_model_init(AdgModel *model)
 106 {
 107     AdgModelPrivate *priv = G_TYPE_INSTANCE_GET_PRIVATE(model, ADG_TYPE_MODEL,
 108                                                         AdgModelPrivate);
 109     model->priv = priv;
 110 }
 111
 112 static void
 113 get_property(GObject *object,
 114              guint prop_id, GValue *value, GParamSpec *pspec)
 115 {
 116     /* TODO: this is only a placeholder */
 117
 118     switch (prop_id) {
 119     default:
 120         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 121         break;
 122     }
 123 }
 124
 125 static void
 126 set_property(GObject *object,
 127              guint prop_id, const GValue *value, GParamSpec *pspec)
 128 {
 129     /* TODO: this is only a placeholder */
 130
 131     switch (prop_id) {
 132     default:
 133         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 134         break;
 135     }
 136 }
 137
 138
 139 /**
 140  * adg_model_changed:
 141  * @model: an #AdgModel
 142  *
 143  * Emits the "changed" signal on @model.
 144  *
 145  * This function is only useful in model implementations.
 146  */
 147 void
 148 adg_model_changed(AdgModel *model)
 149 {
 150     g_return_if_fail(ADG_IS_MODEL(model));
 151
 152     g_signal_emit(model, signals[CHANGED], 0);
 153 }
 154
 155
 156 static void
 157 changed(AdgModel *model)
 158 {
 159 }