src/adg/adg-param-dress.c

   1 /* ADG - Automatic Drawing Generation
   2  * Copyright (C) 2007-2019  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_are_related() documentation for details on what
  32  * <emphasis>related</emphasis> 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 #define ADG_PARAM_SPEC_DRESS(pspec)     (G_TYPE_CHECK_INSTANCE_CAST((pspec), ADG_TYPE_PARAM_DRESS, AdgParamSpecDress))
  47
  48
  49 typedef struct _AdgParamSpecDress AdgParamSpecDress;
  50
  51 struct _AdgParamSpecDress {
  52     GParamSpecEnum parent;
  53     AdgDress       source_dress;
  54 };
  55
  56
  57 static void     _adg_param_dress_init           (GParamSpec   *pspec);
  58 static void     _adg_param_dress_set_default    (GParamSpec   *pspec,
  59                                                  GValue       *value);
  60 static gboolean _adg_param_dress_validate       (GParamSpec   *pspec,
  61                                                  GValue       *value);
  62 static gint     _adg_param_dress_cmp            (GParamSpec   *pspec,
  63                                                  const GValue *value1,
  64                                                  const GValue *value2);
  65
  66
  67 GType
  68 adg_param_dress_get_type(void)
  69 {
  70     static GType type = 0;
  71
  72     if (G_UNLIKELY(type == 0)) {
  73         /* const */ GParamSpecTypeInfo pspec_info = {
  74             sizeof(AdgParamSpecDress),    /* instance_size */
  75             0,                            /* n_preallocs */
  76             _adg_param_dress_init,
  77             G_TYPE_INVALID,               /* value_type */
  78             NULL,                         /* finalize */
  79             _adg_param_dress_set_default,
  80             _adg_param_dress_validate,
  81             _adg_param_dress_cmp,
  82         };
  83         pspec_info.value_type = ADG_TYPE_DRESS;
  84         type = g_param_type_register_static(g_intern_static_string("AdgParamDress"),
  85                                             &pspec_info);
  86     }
  87
  88     return type;
  89 }
  90
  91
  92 /**
  93  * adg_param_spec_dress:
  94  * @name:  canonical name
  95  * @nick:  nickname of the param
  96  * @blurb: brief desciption
  97  * @dress: the #AdgDress dress
  98  * @flags: a combination of #GParamFlags
  99  *
 100  * Creates a param spec to hold a dress value. This is similar to
 101  * g_param_spec_enum() but rejects a new dress value if it is not
 102  * related with the old one. The setting is performed via
 103  * adg_dress_set(), so check its documentation for details.
 104  *
 105  * Returns: (transfer full): the newly allocated #GParamSpec.
 106  *
 107  * Since: 1.0
 108  **/
 109 GParamSpec *
 110 adg_param_spec_dress(const gchar *name, const gchar *nick, const gchar *blurb,
 111                      AdgDress dress, GParamFlags flags)
 112 {
 113     AdgParamSpecDress *dspec;
 114
 115     dspec = g_param_spec_internal(ADG_TYPE_PARAM_DRESS,
 116                                   name, nick, blurb, flags);
 117     dspec->source_dress = dress;
 118
 119     return (GParamSpec *) dspec;
 120 }
 121
 122
 123 static void
 124 _adg_param_dress_init(GParamSpec *pspec)
 125 {
 126     AdgParamSpecDress *dspec = ADG_PARAM_SPEC_DRESS(pspec);
 127     dspec->source_dress = ADG_DRESS_UNDEFINED;
 128 }
 129
 130 static void
 131 _adg_param_dress_set_default(GParamSpec *pspec,
 132                              GValue     *value)
 133 {
 134     value->data[0].v_long = ADG_PARAM_SPEC_DRESS(pspec)->source_dress;
 135 }
 136
 137 static gboolean
 138 _adg_param_dress_validate(GParamSpec *pspec, GValue *value)
 139 {
 140     AdgParamSpecDress *dspec;
 141     AdgDress *dress;
 142     AdgDress wanted_dress;
 143
 144     dspec = ADG_PARAM_SPEC_DRESS(pspec);
 145     dress = (AdgDress *) &value->data[0].v_long;
 146     wanted_dress = *dress;
 147
 148     /* Fallback to the source dress, returned in case of errors */
 149     *dress = dspec->source_dress;
 150
 151     /* This method will fail (that is, it leaves *dress untouched)
 152      * if the current *dress value (source_dress) and wanted_dress
 153      * are not related */
 154     adg_dress_set(dress, wanted_dress);
 155
 156     return *dress != wanted_dress;
 157 }
 158
 159 static gint
 160 _adg_param_dress_cmp(GParamSpec   *pspec,
 161                      const GValue *value1,
 162                      const GValue *value2)
 163 {
 164     glong v1 = value1->data[0].v_long;
 165     glong v2 = value2->data[0].v_long;
 166
 167     return v1 < v2 ? -1 : (v1 > v2);
 168 }