src/adg/adg-param-dress.c

   1 /* ADG - Automatic Drawing Generation
   2  * Copyright (C) 2007,2008,2009,2010,2011,2012,2013  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-param-dress
  23  * @Section_Id:AdgParamDress
  24  * @title: AdgParamDress
  25  * @short_description: Metadata for dress specification
  26  *
  27  * The %ADG_TYPE_PARAM_DRESS type is a parameter specification
  28  * compatible with %G_TYPE_PARAM_ENUM that provides additional
  29  * validation: it rejects values that are incompatibles (that
  30  * is, that are not related) with the current one. Check the
  31  * adg_dress_is_related() documentation for details on what
  32  * "related" means.
  33  *
  34  * Internally, the value setting is performed by calling the
  35  * adg_dress_set() API.
  36  *
  37  * Since: 1.0
  38  **/
  39
  40
  41 #include "adg-internal.h"
  42 #include "adg-dress.h"
  43
  44 #include "adg-param-dress.h"
  45
  46
  47 typedef struct _AdgParamSpecDress AdgParamSpecDress;
  48
  49 struct _AdgParamSpecDress {
  50     GParamSpecEnum parent;
  51     AdgDress       source_dress;
  52 };
  53
  54
  55 static void     _adg_param_dress_init           (GParamSpec   *pspec);
  56 static void     _adg_param_dress_set_default    (GParamSpec   *pspec,
  57                                                  GValue       *value);
  58 static gboolean _adg_param_dress_validate       (GParamSpec   *pspec,
  59                                                  GValue       *value);
  60 static gint     _adg_param_dress_cmp            (GParamSpec   *pspec,
  61                                                  const GValue *value1,
  62                                                  const GValue *value2);
  63
  64
  65 GType
  66 adg_param_dress_get_type(void)
  67 {
  68     static GType type = 0;
  69
  70     if (G_UNLIKELY(type == 0)) {
  71         /* const */ GParamSpecTypeInfo pspec_info = {
  72             sizeof(AdgParamSpecDress),    /* instance_size */
  73             0,                            /* n_preallocs */
  74             _adg_param_dress_init,
  75             G_TYPE_INVALID,               /* value_type */
  76             NULL,                         /* finalize */
  77             _adg_param_dress_set_default,
  78             _adg_param_dress_validate,
  79             _adg_param_dress_cmp,
  80         };
  81         pspec_info.value_type = ADG_TYPE_DRESS;
  82         type = g_param_type_register_static(g_intern_static_string("AdgParamDress"),
  83                                             &pspec_info);
  84     }
  85
  86     return type;
  87 }
  88
  89
  90 /**
  91  * adg_param_spec_dress:
  92  * @name:  canonical name
  93  * @nick:  nickname of the param
  94  * @blurb: brief desciption
  95  * @dress: the #AdgDress dress
  96  * @flags: a combination of #GParamFlags
  97  *
  98  * Creates a param spec to hold a dress value. This is similar to
  99  * g_param_spec_enum() but rejects a new dress value if it is not
 100  * related with the old one. The setting is performed via
 101  * adg_dress_set(), so check its documentation for details.
 102  *
 103  * Returns: (transfer full): the newly allocated #GParamSpec.
 104  *
 105  * Since: 1.0
 106  **/
 107 GParamSpec *
 108 adg_param_spec_dress(const gchar *name, const gchar *nick, const gchar *blurb,
 109                      AdgDress dress, GParamFlags flags)
 110 {
 111     AdgParamSpecDress *dspec;
 112
 113     dspec = g_param_spec_internal(ADG_TYPE_PARAM_DRESS,
 114                                   name, nick, blurb, flags);
 115     dspec->source_dress = dress;
 116
 117     return (GParamSpec *) dspec;
 118 }
 119
 120
 121 static void
 122 _adg_param_dress_init(GParamSpec *pspec)
 123 {
 124     AdgParamSpecDress *dspec = ADG_PARAM_SPEC_DRESS(pspec);
 125     dspec->source_dress = ADG_DRESS_UNDEFINED;
 126 }
 127
 128 static void
 129 _adg_param_dress_set_default(GParamSpec *pspec,
 130                              GValue     *value)
 131 {
 132     value->data[0].v_long = ADG_PARAM_SPEC_DRESS(pspec)->source_dress;
 133 }
 134
 135 static gboolean
 136 _adg_param_dress_validate(GParamSpec *pspec, GValue *value)
 137 {
 138     AdgParamSpecDress *dspec;
 139     AdgDress *dress;
 140     AdgDress wanted_dress;
 141
 142     dspec = ADG_PARAM_SPEC_DRESS(pspec);
 143     dress = (AdgDress *) &value->data[0].v_long;
 144     wanted_dress = *dress;
 145
 146     /* Fallback to the source dress, returned in case of errors */
 147     *dress = dspec->source_dress;
 148
 149     /* This method will fail (that is, it leaves *dress untouched)
 150      * if the current *dress value (source_dress) and wanted_dress
 151      * are not related */
 152     adg_dress_set(dress, wanted_dress);
 153
 154     return *dress != wanted_dress;
 155 }
 156
 157 static gint
 158 _adg_param_dress_cmp(GParamSpec   *pspec,
 159                      const GValue *value1,
 160                      const GValue *value2)
 161 {
 162     glong v1 = value1->data[0].v_long;
 163     glong v2 = value2->data[0].v_long;
 164
 165     return v1 < v2 ? -1 : (v1 > v2);
 166 }