gobject/gparam.h

   1 /* GObject - GLib Type, Object, Parameter and Signal Library
   2  * Copyright (C) 1997-1999, 2000-2001 Tim Janik and Red Hat, Inc.
   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
  15  * Public License along with this library; if not, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  *
  19  * gparam.h: GParamSpec base class implementation
  20  */
  21 #ifndef __G_PARAM_H__
  22 #define __G_PARAM_H__
  23
  24
  25 #include        <gobject/gvalue.h>
  26
  27
  28 #ifdef __cplusplus
  29 extern "C" {
  30 #endif /* __cplusplus */
  31
  32
  33 /* --- type macros --- */
  34 #define G_TYPE_IS_PARAM(type)           (G_TYPE_FUNDAMENTAL (type) == G_TYPE_PARAM)
  35 #define G_PARAM_SPEC_TYPE(pspec)        (G_TYPE_FROM_INSTANCE (pspec))
  36 #define G_PARAM_SPEC_TYPE_NAME(pspec)   (g_type_name (G_PARAM_SPEC_TYPE (pspec)))
  37 #define G_PARAM_SPEC(pspec)             (G_TYPE_CHECK_INSTANCE_CAST ((pspec), G_TYPE_PARAM, GParamSpec))
  38 #define G_IS_PARAM_SPEC(pspec)          (G_TYPE_CHECK_INSTANCE_TYPE ((pspec), G_TYPE_PARAM))
  39 #define G_PARAM_SPEC_GET_CLASS(pspec)   (G_TYPE_INSTANCE_GET_CLASS ((pspec), G_TYPE_PARAM, GParamSpecClass))
  40 #define G_PARAM_SPEC_VALUE_TYPE(pspec)  (G_PARAM_SPEC (pspec)->value_type)
  41 #define G_VALUE_HOLDS_PARAM(value)      (G_TYPE_CHECK_VALUE_TYPE ((value), G_TYPE_PARAM))
  42
  43
  44 /* --- flags --- */
  45 typedef enum
  46 {
  47   G_PARAM_READABLE            = 1 << 0,
  48   G_PARAM_WRITABLE            = 1 << 1,
  49   G_PARAM_CONSTRUCT           = 1 << 2,
  50   G_PARAM_CONSTRUCT_ONLY      = 1 << 3,
  51   G_PARAM_LAX_VALIDATION      = 1 << 4,
  52   G_PARAM_PRIVATE             = 1 << 5
  53 } GParamFlags;
  54 #define G_PARAM_READWRITE       (G_PARAM_READABLE | G_PARAM_WRITABLE)
  55 #define G_PARAM_MASK            (0x000000ff)
  56 /* bits in the range 0xffffff00 are reserved for 3rd party usage */
  57 #define G_PARAM_USER_SHIFT      (8)
  58
  59
  60 /* --- typedefs & structures --- */
  61 typedef struct _GParamSpec      GParamSpec;
  62 typedef struct _GParamSpecClass GParamSpecClass;
  63 typedef struct _GParamSpecPool  GParamSpecPool;
  64 struct _GParamSpec
  65 {
  66   GTypeInstance  g_type_instance;
  67
  68   gchar         *name;
  69   gchar         *nick;
  70   gchar         *blurb;
  71   GParamFlags    flags;
  72   GType          value_type;
  73
  74   /*< private >*/
  75   GType          owner_type;
  76   GData         *qdata;
  77   guint          ref_count;
  78 };
  79 struct _GParamSpecClass
  80 {
  81   GTypeClass      g_type_class;
  82
  83   GType           value_type;
  84
  85   void          (*finalize)             (GParamSpec   *pspec);
  86
  87   /* GParam methods */
  88   void          (*value_set_default)    (GParamSpec   *pspec,
  89                                          GValue       *value);
  90   gboolean      (*value_validate)       (GParamSpec   *pspec,
  91                                          GValue       *value);
  92   gint          (*values_cmp)           (GParamSpec   *pspec,
  93                                          const GValue *value1,
  94                                          const GValue *value2);
  95 };
  96
  97
  98 /* --- prototypes --- */
  99 GParamSpec*     g_param_spec_ref                (GParamSpec    *pspec);
 100 void            g_param_spec_unref              (GParamSpec    *pspec);
 101 void            g_param_spec_sink               (GParamSpec    *pspec);
 102 gpointer        g_param_spec_get_qdata          (GParamSpec    *pspec,
 103                                                  GQuark         quark);
 104 void            g_param_spec_set_qdata          (GParamSpec    *pspec,
 105                                                  GQuark         quark,
 106                                                  gpointer       data);
 107 void            g_param_spec_set_qdata_full     (GParamSpec    *pspec,
 108                                                  GQuark         quark,
 109                                                  gpointer       data,
 110                                                  GDestroyNotify destroy);
 111 gpointer        g_param_spec_steal_qdata        (GParamSpec    *pspec,
 112                                                  GQuark         quark);
 113 void            g_param_value_set_default       (GParamSpec    *pspec,
 114                                                  GValue        *value);
 115 gboolean        g_param_value_defaults          (GParamSpec    *pspec,
 116                                                  GValue        *value);
 117 gboolean        g_param_value_validate          (GParamSpec    *pspec,
 118                                                  GValue        *value);
 119 gboolean        g_param_value_convert           (GParamSpec    *dest_value_spec,
 120                                                  const GValue  *src_value,
 121                                                  GValue        *dest_value,
 122                                                  gboolean       strict_validation);
 123 gint            g_param_values_cmp              (GParamSpec    *pspec,
 124                                                  const GValue  *value1,
 125                                                  const GValue  *value2);
 126 void            g_value_set_param               (GValue        *value,
 127                                                  GParamSpec    *param);
 128 GParamSpec*     g_value_get_param               (const GValue  *value);
 129 GParamSpec*     g_value_dup_param               (const GValue  *value);
 130
 131
 132 /* --- convenience functions --- */
 133 typedef struct _GParamSpecTypeInfo GParamSpecTypeInfo;
 134 struct _GParamSpecTypeInfo
 135 {
 136   /* type system portion */
 137   guint16         instance_size;                               /* obligatory */
 138   guint16         n_preallocs;                                 /* optional */
 139   void          (*instance_init)        (GParamSpec   *pspec); /* optional */
 140
 141   /* class portion */
 142   GType           value_type;                                  /* obligatory */
 143   void          (*finalize)             (GParamSpec   *pspec); /* optional */
 144   void          (*value_set_default)    (GParamSpec   *pspec,  /* recommended */
 145                                          GValue       *value);
 146   gboolean      (*value_validate)       (GParamSpec   *pspec,  /* optional */
 147                                          GValue       *value);
 148   gint          (*values_cmp)           (GParamSpec   *pspec,  /* recommended */
 149                                          const GValue *value1,
 150                                          const GValue *value2);
 151 };
 152 GType   g_param_type_register_static    (const gchar              *name,
 153                                          const GParamSpecTypeInfo *pspec_info);
 154
 155
 156 /* --- protected --- */
 157 gpointer        g_param_spec_internal           (GType          param_type,
 158                                                  const gchar   *name,
 159                                                  const gchar   *nick,
 160                                                  const gchar   *blurb,
 161                                                  GParamFlags    flags);
 162 GParamSpecPool* g_param_spec_pool_new           (gboolean       type_prefixing);
 163 void            g_param_spec_pool_insert        (GParamSpecPool *pool,
 164                                                  GParamSpec     *pspec,
 165                                                  GType           owner_type);
 166 void            g_param_spec_pool_remove        (GParamSpecPool *pool,
 167                                                  GParamSpec     *pspec);
 168 GParamSpec*     g_param_spec_pool_lookup        (GParamSpecPool *pool,
 169                                                  const gchar    *param_name,
 170                                                  GType           owner_type,
 171                                                  gboolean        walk_ancestors);
 172
 173
 174 /* contracts:
 175  *
 176  * gboolean value_validate (GParamSpec *pspec,
 177  *                          GValue     *value):
 178  *      modify value contents in the least destructive way, so
 179  *      that it complies with pspec's requirements (i.e.
 180  *      according to minimum/maximum ranges etc...). return
 181  *      whether modification was necessary.
 182  *
 183  * gint values_cmp (GParamSpec   *pspec,
 184  *                  const GValue *value1,
 185  *                  const GValue *value2):
 186  *      return value1 - value2, i.e. <0 if value1 < value2,
 187  *      >0 if value1 > value2, and 0 otherwise (they are equal)
 188  */
 189
 190 #ifdef __cplusplus
 191 }
 192 #endif /* __cplusplus */
 193
 194 #endif /* __G_PARAM_H__ */