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 #define PARENT_CLASS ((GObjectClass *) adg_model_parent_class)
  49
  50
  51 enum {
  52     PROP_0
  53 };
  54
  55 enum {
  56     CHANGED,
  57     LAST_SIGNAL
  58 };
  59
  60
  61 static void     finalize                (GObject        *object);
  62 static void     get_property            (GObject        *object,
  63                                          guint           prop_id,
  64                                          GValue         *value,
  65                                          GParamSpec     *pspec);
  66 static void     set_property            (GObject        *object,
  67                                          guint           prop_id,
  68                                          const GValue   *value,
  69                                          GParamSpec     *pspec);
  70 static void     changed                 (AdgModel       *model);
  71
  72 static guint signals[LAST_SIGNAL] = { 0 };
  73
  74
  75 G_DEFINE_ABSTRACT_TYPE(AdgModel, adg_model, G_TYPE_OBJECT);
  76
  77
  78 static void
  79 adg_model_class_init(AdgModelClass *klass)
  80 {
  81     GObjectClass *gobject_class;
  82
  83     gobject_class = (GObjectClass *) klass;
  84
  85     g_type_class_add_private(klass, sizeof(AdgModelPrivate));
  86
  87     gobject_class->finalize = finalize;
  88     gobject_class->get_property = get_property;
  89     gobject_class->set_property = set_property;
  90
  91     klass->changed = changed;
  92
  93     /**
  94      * AdgModel::changed:
  95      * @model: an #AdgModel
  96      *
  97      * Notificates that the model has changed. By default, the model
  98      * cache is invalidated.
  99      **/
 100     signals[CHANGED] = g_signal_new("changed", ADG_TYPE_MODEL,
 101                                      G_SIGNAL_RUN_LAST|G_SIGNAL_NO_RECURSE,
 102                                      G_STRUCT_OFFSET(AdgModelClass, changed),
 103                                      NULL, NULL,
 104                                      g_cclosure_marshal_VOID__VOID,
 105                                      G_TYPE_NONE, 0);
 106 }
 107
 108 static void
 109 adg_model_init(AdgModel *model)
 110 {
 111     AdgModelPrivate *priv = G_TYPE_INSTANCE_GET_PRIVATE(model, ADG_TYPE_MODEL,
 112                                                         AdgModelPrivate);
 113     model->priv = priv;
 114 }
 115
 116 static void
 117 finalize(GObject *object)
 118 {
 119     /* TODO: this is only a placeholder */
 120
 121     PARENT_CLASS->finalize(object);
 122 }
 123
 124
 125 static void
 126 get_property(GObject *object,
 127              guint prop_id, 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 static void
 139 set_property(GObject *object,
 140              guint prop_id, const GValue *value, GParamSpec *pspec)
 141 {
 142     /* TODO: this is only a placeholder */
 143
 144     switch (prop_id) {
 145     default:
 146         G_OBJECT_WARN_INVALID_PROPERTY_ID(object, prop_id, pspec);
 147         break;
 148     }
 149 }
 150
 151
 152 /**
 153  * adg_model_changed:
 154  * @model: an #AdgModel
 155  *
 156  * Emits the "changed" signal on @model.
 157  *
 158  * This function is only useful in model implementations.
 159  */
 160 void
 161 adg_model_changed(AdgModel *model)
 162 {
 163     g_return_if_fail(ADG_IS_MODEL(model));
 164
 165     g_signal_emit(model, signals[CHANGED], 0);
 166 }
 167
 168
 169 static void
 170 changed(AdgModel *model)
 171 {
 172 }