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, see <http://www.gnu.org/licenses/>.
  16  *
  17  * gparam.h: GParamSpec base class implementation
  18  */
  19 #ifndef __G_PARAM_H__
  20 #define __G_PARAM_H__
  21
  22 #if !defined (__GLIB_GOBJECT_H_INSIDE__) && !defined (GOBJECT_COMPILATION)
  23 #error "Only <glib-object.h> can be included directly."
  24 #endif
  25
  26 #include        <gobject/gvalue.h>
  27
  28 G_BEGIN_DECLS
  29
  30 /* --- standard type macros --- */
  31 /**
  32  * G_TYPE_IS_PARAM:
  33  * @type: a #GType ID
  34  *
  35  * Checks whether @type "is a" %G_TYPE_PARAM.
  36  */
  37 #define G_TYPE_IS_PARAM(type)           (G_TYPE_FUNDAMENTAL (type) == G_TYPE_PARAM)
  38 /**
  39  * G_PARAM_SPEC:
  40  * @pspec: a valid #GParamSpec
  41  *
  42  * Casts a derived #GParamSpec object (e.g. of type #GParamSpecInt) into
  43  * a #GParamSpec object.
  44  */
  45 #define G_PARAM_SPEC(pspec)             (G_TYPE_CHECK_INSTANCE_CAST ((pspec), G_TYPE_PARAM, GParamSpec))
  46 /**
  47  * G_IS_PARAM_SPEC:
  48  * @pspec: a #GParamSpec
  49  *
  50  * Checks whether @pspec "is a" valid #GParamSpec structure of type %G_TYPE_PARAM
  51  * or derived.
  52  */
  53 #define G_IS_PARAM_SPEC(pspec)          (G_TYPE_CHECK_INSTANCE_TYPE ((pspec), G_TYPE_PARAM))
  54 /**
  55  * G_PARAM_SPEC_CLASS:
  56  * @pclass: a valid #GParamSpecClass
  57  *
  58  * Casts a derived #GParamSpecClass structure into a #GParamSpecClass structure.
  59  */
  60 #define G_PARAM_SPEC_CLASS(pclass)      (G_TYPE_CHECK_CLASS_CAST ((pclass), G_TYPE_PARAM, GParamSpecClass))
  61 /**
  62  * G_IS_PARAM_SPEC_CLASS:
  63  * @pclass: a #GParamSpecClass
  64  *
  65  * Checks whether @pclass "is a" valid #GParamSpecClass structure of type
  66  * %G_TYPE_PARAM or derived.
  67  */
  68 #define G_IS_PARAM_SPEC_CLASS(pclass)   (G_TYPE_CHECK_CLASS_TYPE ((pclass), G_TYPE_PARAM))
  69 /**
  70  * G_PARAM_SPEC_GET_CLASS:
  71  * @pspec: a valid #GParamSpec
  72  *
  73  * Retrieves the #GParamSpecClass of a #GParamSpec.
  74  */
  75 #define G_PARAM_SPEC_GET_CLASS(pspec)   (G_TYPE_INSTANCE_GET_CLASS ((pspec), G_TYPE_PARAM, GParamSpecClass))
  76
  77
  78 /* --- convenience macros --- */
  79 /**
  80  * G_PARAM_SPEC_TYPE:
  81  * @pspec: a valid #GParamSpec
  82  *
  83  * Retrieves the #GType of this @pspec.
  84  */
  85 #define G_PARAM_SPEC_TYPE(pspec)        (G_TYPE_FROM_INSTANCE (pspec))
  86 /**
  87  * G_PARAM_SPEC_TYPE_NAME:
  88  * @pspec: a valid #GParamSpec
  89  *
  90  * Retrieves the #GType name of this @pspec.
  91  */
  92 #define G_PARAM_SPEC_TYPE_NAME(pspec)   (g_type_name (G_PARAM_SPEC_TYPE (pspec)))
  93 /**
  94  * G_PARAM_SPEC_VALUE_TYPE:
  95  * @pspec: a valid #GParamSpec
  96  *
  97  * Retrieves the #GType to initialize a #GValue for this parameter.
  98  */
  99 #define G_PARAM_SPEC_VALUE_TYPE(pspec)  (G_PARAM_SPEC (pspec)->value_type)
 100 /**
 101  * G_VALUE_HOLDS_PARAM:
 102  * @value: a valid #GValue structure
 103  *
 104  * Checks whether the given #GValue can hold values derived from type %G_TYPE_PARAM.
 105  *
 106  * Returns: %TRUE on success.
 107  */
 108 #define G_VALUE_HOLDS_PARAM(value)      (G_TYPE_CHECK_VALUE_TYPE ((value), G_TYPE_PARAM))
 109
 110
 111 /* --- flags --- */
 112 /**
 113  * GParamFlags:
 114  * @G_PARAM_READABLE: the parameter is readable
 115  * @G_PARAM_WRITABLE: the parameter is writable
 116  * @G_PARAM_CONSTRUCT: the parameter will be set upon object construction
 117  * @G_PARAM_CONSTRUCT_ONLY: the parameter will only be set upon object construction
 118  * @G_PARAM_LAX_VALIDATION: upon parameter conversion (see g_param_value_convert())
 119  *  strict validation is not required
 120  * @G_PARAM_STATIC_NAME: the string used as name when constructing the
 121  *  parameter is guaranteed to remain valid and
 122  *  unmodified for the lifetime of the parameter.
 123  *  Since 2.8
 124  * @G_PARAM_STATIC_NICK: the string used as nick when constructing the
 125  *  parameter is guaranteed to remain valid and
 126  *  unmmodified for the lifetime of the parameter.
 127  *  Since 2.8
 128  * @G_PARAM_STATIC_BLURB: the string used as blurb when constructing the
 129  *  parameter is guaranteed to remain valid and
 130  *  unmodified for the lifetime of the parameter.
 131  *  Since 2.8
 132  * @G_PARAM_PRIVATE: internal
 133  * @G_PARAM_DEPRECATED: the parameter is deprecated and will be removed
 134  *  in a future version. A warning will be generated if it is used
 135  *  while running with G_ENABLE_DIAGNOSTIC=1.
 136  *  Since 2.26
 137  *
 138  * Through the #GParamFlags flag values, certain aspects of parameters
 139  * can be configured. See also #G_PARAM_READWRITE and #G_PARAM_STATIC_STRINGS.
 140  */
 141 typedef enum
 142 {
 143   G_PARAM_READABLE            = 1 << 0,
 144   G_PARAM_WRITABLE            = 1 << 1,
 145   G_PARAM_CONSTRUCT           = 1 << 2,
 146   G_PARAM_CONSTRUCT_ONLY      = 1 << 3,
 147   G_PARAM_LAX_VALIDATION      = 1 << 4,
 148   G_PARAM_STATIC_NAME         = 1 << 5,
 149 #ifndef G_DISABLE_DEPRECATED
 150   G_PARAM_PRIVATE             = G_PARAM_STATIC_NAME,
 151 #endif
 152   G_PARAM_STATIC_NICK         = 1 << 6,
 153   G_PARAM_STATIC_BLURB        = 1 << 7,
 154   /* User defined flags go up to 30 */
 155   G_PARAM_DEPRECATED          = 1 << 31
 156 } GParamFlags;
 157 /**
 158  * G_PARAM_READWRITE:
 159  *
 160  * #GParamFlags value alias for %G_PARAM_READABLE | %G_PARAM_WRITABLE.
 161  */
 162 #define G_PARAM_READWRITE       (G_PARAM_READABLE | G_PARAM_WRITABLE)
 163 /**
 164  * G_PARAM_STATIC_STRINGS:
 165  *
 166  * #GParamFlags value alias for %G_PARAM_STATIC_NAME | %G_PARAM_STATIC_NICK | %G_PARAM_STATIC_BLURB.
 167  *
 168  * Since 2.13.0
 169  */
 170 #define G_PARAM_STATIC_STRINGS (G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB)
 171 /* bits in the range 0xffffff00 are reserved for 3rd party usage */
 172 /**
 173  * G_PARAM_MASK:
 174  *
 175  * Mask containing the bits of #GParamSpec.flags which are reserved for GLib.
 176  */
 177 #define G_PARAM_MASK            (0x000000ff)
 178 /**
 179  * G_PARAM_USER_SHIFT:
 180  *
 181  * Minimum shift count to be used for user defined flags, to be stored in
 182  * #GParamSpec.flags. The maximum allowed is 30 + G_PARAM_USER_SHIFT.
 183  */
 184 #define G_PARAM_USER_SHIFT      (8)
 185
 186 /* --- typedefs & structures --- */
 187 typedef struct _GParamSpec      GParamSpec;
 188 typedef struct _GParamSpecClass GParamSpecClass;
 189 typedef struct _GParameter      GParameter;
 190 typedef struct _GParamSpecPool  GParamSpecPool;
 191 /**
 192  * GParamSpec:
 193  * @g_type_instance: private #GTypeInstance portion
 194  * @name: name of this parameter: always an interned string
 195  * @flags: #GParamFlags flags for this parameter
 196  * @value_type: the #GValue type for this parameter
 197  * @owner_type: #GType type that uses (introduces) this parameter
 198  *
 199  * All other fields of the <structname>GParamSpec</structname> struct are private and
 200  * should not be used directly.
 201  */
 202 struct _GParamSpec
 203 {
 204   GTypeInstance  g_type_instance;
 205
 206   const gchar   *name;          /* interned string */
 207   GParamFlags    flags;
 208   GType          value_type;
 209   GType          owner_type;    /* class or interface using this property */
 210
 211   /*< private >*/
 212   gchar         *_nick;
 213   gchar         *_blurb;
 214   GData         *qdata;
 215   guint          ref_count;
 216   guint          param_id;      /* sort-criteria */
 217 };
 218 /**
 219  * GParamSpecClass:
 220  * @g_type_class: the parent class
 221  * @value_type: the #GValue type for this parameter
 222  * @finalize: The instance finalization function (optional), should chain
 223  *  up to the finalize method of the parent class.
 224  * @value_set_default: Resets a @value to the default value for this type
 225  *  (recommended, the default is g_value_reset()), see
 226  *  g_param_value_set_default().
 227  * @value_validate: Ensures that the contents of @value comply with the
 228  *  specifications set out by this type (optional), see
 229  *  g_param_value_validate().
 230  * @values_cmp: Compares @value1 with @value2 according to this type
 231  *  (recommended, the default is memcmp()), see g_param_values_cmp().
 232  *
 233  * The class structure for the <structname>GParamSpec</structname> type.
 234  * Normally, <structname>GParamSpec</structname> classes are filled by
 235  * g_param_type_register_static().
 236  */
 237 struct _GParamSpecClass
 238 {
 239   GTypeClass      g_type_class;
 240
 241   GType           value_type;
 242
 243   void          (*finalize)             (GParamSpec   *pspec);
 244
 245   /* GParam methods */
 246   void          (*value_set_default)    (GParamSpec   *pspec,
 247                                          GValue       *value);
 248   gboolean      (*value_validate)       (GParamSpec   *pspec,
 249                                          GValue       *value);
 250   gint          (*values_cmp)           (GParamSpec   *pspec,
 251                                          const GValue *value1,
 252                                          const GValue *value2);
 253   /*< private >*/
 254   gpointer        dummy[4];
 255 };
 256 /**
 257  * GParameter:
 258  * @name: the parameter name
 259  * @value: the parameter value
 260  *
 261  * The <structname>GParameter</structname> struct is an auxiliary structure used
 262  * to hand parameter name/value pairs to g_object_newv().
 263  */
 264 struct _GParameter /* auxiliary structure for _setv() variants */
 265 {
 266   const gchar *name;
 267   GValue       value;
 268 };
 269
 270
 271 /* --- prototypes --- */
 272 GLIB_AVAILABLE_IN_ALL
 273 GParamSpec*     g_param_spec_ref                (GParamSpec    *pspec);
 274 GLIB_AVAILABLE_IN_ALL
 275 void            g_param_spec_unref              (GParamSpec    *pspec);
 276 GLIB_AVAILABLE_IN_ALL
 277 void            g_param_spec_sink               (GParamSpec    *pspec);
 278 GLIB_AVAILABLE_IN_ALL
 279 GParamSpec*     g_param_spec_ref_sink           (GParamSpec    *pspec);
 280 GLIB_AVAILABLE_IN_ALL
 281 gpointer        g_param_spec_get_qdata          (GParamSpec    *pspec,
 282                                                  GQuark         quark);
 283 GLIB_AVAILABLE_IN_ALL
 284 void            g_param_spec_set_qdata          (GParamSpec    *pspec,
 285                                                  GQuark         quark,
 286                                                  gpointer       data);
 287 GLIB_AVAILABLE_IN_ALL
 288 void            g_param_spec_set_qdata_full     (GParamSpec    *pspec,
 289                                                  GQuark         quark,
 290                                                  gpointer       data,
 291                                                  GDestroyNotify destroy);
 292 GLIB_AVAILABLE_IN_ALL
 293 gpointer        g_param_spec_steal_qdata        (GParamSpec    *pspec,
 294                                                  GQuark         quark);
 295 GLIB_AVAILABLE_IN_ALL
 296 GParamSpec*     g_param_spec_get_redirect_target (GParamSpec   *pspec);
 297
 298 GLIB_AVAILABLE_IN_ALL
 299 void            g_param_value_set_default       (GParamSpec    *pspec,
 300                                                  GValue        *value);
 301 GLIB_AVAILABLE_IN_ALL
 302 gboolean        g_param_value_defaults          (GParamSpec    *pspec,
 303                                                  GValue        *value);
 304 GLIB_AVAILABLE_IN_ALL
 305 gboolean        g_param_value_validate          (GParamSpec    *pspec,
 306                                                  GValue        *value);
 307 GLIB_AVAILABLE_IN_ALL
 308 gboolean        g_param_value_convert           (GParamSpec    *pspec,
 309                                                  const GValue  *src_value,
 310                                                  GValue        *dest_value,
 311                                                  gboolean       strict_validation);
 312 GLIB_AVAILABLE_IN_ALL
 313 gint            g_param_values_cmp              (GParamSpec    *pspec,
 314                                                  const GValue  *value1,
 315                                                  const GValue  *value2);
 316 GLIB_AVAILABLE_IN_ALL
 317 const gchar *   g_param_spec_get_name           (GParamSpec    *pspec);
 318 GLIB_AVAILABLE_IN_ALL
 319 const gchar *   g_param_spec_get_nick           (GParamSpec    *pspec);
 320 GLIB_AVAILABLE_IN_ALL
 321 const gchar *   g_param_spec_get_blurb          (GParamSpec    *pspec);
 322 GLIB_AVAILABLE_IN_ALL
 323 void            g_value_set_param               (GValue        *value,
 324                                                  GParamSpec    *param);
 325 GLIB_AVAILABLE_IN_ALL
 326 GParamSpec*     g_value_get_param               (const GValue  *value);
 327 GLIB_AVAILABLE_IN_ALL
 328 GParamSpec*     g_value_dup_param               (const GValue  *value);
 329
 330
 331 GLIB_AVAILABLE_IN_ALL
 332 void           g_value_take_param               (GValue        *value,
 333                                                  GParamSpec    *param);
 334 GLIB_DEPRECATED_FOR(g_value_take_param)
 335 void           g_value_set_param_take_ownership (GValue        *value,
 336                                                  GParamSpec    *param);
 337 GLIB_AVAILABLE_IN_2_36
 338 const GValue *  g_param_spec_get_default_value  (GParamSpec     *param);
 339
 340 /* --- convenience functions --- */
 341 typedef struct _GParamSpecTypeInfo GParamSpecTypeInfo;
 342 /**
 343  * GParamSpecTypeInfo:
 344  * @instance_size: Size of the instance (object) structure.
 345  * @n_preallocs: Prior to GLib 2.10, it specified the number of pre-allocated (cached) instances to reserve memory for (0 indicates no caching). Since GLib 2.10, it is ignored, since instances are allocated with the <link linkend="glib-Memory-Slices">slice allocator</link> now.
 346  * @instance_init: Location of the instance initialization function (optional).
 347  * @value_type: The #GType of values conforming to this #GParamSpec
 348  * @finalize: The instance finalization function (optional).
 349  * @value_set_default: Resets a @value to the default value for @pspec
 350  *  (recommended, the default is g_value_reset()), see
 351  *  g_param_value_set_default().
 352  * @value_validate: Ensures that the contents of @value comply with the
 353  *  specifications set out by @pspec (optional), see
 354  *  g_param_value_validate().
 355  * @values_cmp: Compares @value1 with @value2 according to @pspec
 356  *  (recommended, the default is memcmp()), see g_param_values_cmp().
 357  *
 358  * This structure is used to provide the type system with the information
 359  * required to initialize and destruct (finalize) a parameter's class and
 360  * instances thereof.
 361  * The initialized structure is passed to the g_param_type_register_static()
 362  * The type system will perform a deep copy of this structure, so its memory
 363  * does not need to be persistent across invocation of
 364  * g_param_type_register_static().
 365  */
 366 struct _GParamSpecTypeInfo
 367 {
 368   /* type system portion */
 369   guint16         instance_size;                               /* obligatory */
 370   guint16         n_preallocs;                                 /* optional */
 371   void          (*instance_init)        (GParamSpec   *pspec); /* optional */
 372
 373   /* class portion */
 374   GType           value_type;                                  /* obligatory */
 375   void          (*finalize)             (GParamSpec   *pspec); /* optional */
 376   void          (*value_set_default)    (GParamSpec   *pspec,  /* recommended */
 377                                          GValue       *value);
 378   gboolean      (*value_validate)       (GParamSpec   *pspec,  /* optional */
 379                                          GValue       *value);
 380   gint          (*values_cmp)           (GParamSpec   *pspec,  /* recommended */
 381                                          const GValue *value1,
 382                                          const GValue *value2);
 383 };
 384 GLIB_AVAILABLE_IN_ALL
 385 GType   g_param_type_register_static    (const gchar              *name,
 386                                          const GParamSpecTypeInfo *pspec_info);
 387
 388 /* For registering builting types */
 389 GType  _g_param_type_register_static_constant (const gchar              *name,
 390                                                const GParamSpecTypeInfo *pspec_info,
 391                                                GType                     opt_type);
 392
 393
 394 /* --- protected --- */
 395 GLIB_AVAILABLE_IN_ALL
 396 gpointer        g_param_spec_internal           (GType          param_type,
 397                                                  const gchar   *name,
 398                                                  const gchar   *nick,
 399                                                  const gchar   *blurb,
 400                                                  GParamFlags    flags);
 401 GLIB_AVAILABLE_IN_ALL
 402 GParamSpecPool* g_param_spec_pool_new           (gboolean       type_prefixing);
 403 GLIB_AVAILABLE_IN_ALL
 404 void            g_param_spec_pool_insert        (GParamSpecPool *pool,
 405                                                  GParamSpec     *pspec,
 406                                                  GType           owner_type);
 407 GLIB_AVAILABLE_IN_ALL
 408 void            g_param_spec_pool_remove        (GParamSpecPool *pool,
 409                                                  GParamSpec     *pspec);
 410 GLIB_AVAILABLE_IN_ALL
 411 GParamSpec*     g_param_spec_pool_lookup        (GParamSpecPool *pool,
 412                                                  const gchar    *param_name,
 413                                                  GType           owner_type,
 414                                                  gboolean        walk_ancestors);
 415 GLIB_AVAILABLE_IN_ALL
 416 GList*          g_param_spec_pool_list_owned    (GParamSpecPool *pool,
 417                                                  GType           owner_type);
 418 GLIB_AVAILABLE_IN_ALL
 419 GParamSpec**    g_param_spec_pool_list          (GParamSpecPool *pool,
 420                                                  GType           owner_type,
 421                                                  guint          *n_pspecs_p);
 422
 423
 424 /* contracts:
 425  *
 426  * gboolean value_validate (GParamSpec *pspec,
 427  *                          GValue     *value):
 428  *      modify value contents in the least destructive way, so
 429  *      that it complies with pspec's requirements (i.e.
 430  *      according to minimum/maximum ranges etc...). return
 431  *      whether modification was necessary.
 432  *
 433  * gint values_cmp (GParamSpec   *pspec,
 434  *                  const GValue *value1,
 435  *                  const GValue *value2):
 436  *      return value1 - value2, i.e. (-1) if value1 < value2,
 437  *      (+1) if value1 > value2, and (0) otherwise (equality)
 438  */
 439
 440 G_END_DECLS
 441
 442 #endif /* __G_PARAM_H__ */