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 #if !defined (__GLIB_GOBJECT_H_INSIDE__) && !defined (GOBJECT_COMPILATION)
  25 #error "Only <glib-object.h> can be included directly."
  26 #endif
  27
  28 #include        <gobject/gvalue.h>
  29
  30 G_BEGIN_DECLS
  31
  32 /* --- standard type macros --- */
  33 /**
  34  * G_TYPE_IS_PARAM:
  35  * @type: a #GType ID
  36  *
  37  * Checks whether @type "is a" %G_TYPE_PARAM.
  38  */
  39 #define G_TYPE_IS_PARAM(type)           (G_TYPE_FUNDAMENTAL (type) == G_TYPE_PARAM)
  40 /**
  41  * G_PARAM_SPEC:
  42  * @pspec: a valid #GParamSpec
  43  *
  44  * Casts a derived #GParamSpec object (e.g. of type #GParamSpecInt) into
  45  * a #GParamSpec object.
  46  */
  47 #define G_PARAM_SPEC(pspec)             (G_TYPE_CHECK_INSTANCE_CAST ((pspec), G_TYPE_PARAM, GParamSpec))
  48 /**
  49  * G_IS_PARAM_SPEC:
  50  * @pspec: a #GParamSpec
  51  *
  52  * Checks whether @pspec "is a" valid #GParamSpec structure of type %G_TYPE_PARAM
  53  * or derived.
  54  */
  55 #define G_IS_PARAM_SPEC(pspec)          (G_TYPE_CHECK_INSTANCE_TYPE ((pspec), G_TYPE_PARAM))
  56 /**
  57  * G_PARAM_SPEC_CLASS:
  58  * @pclass: a valid #GParamSpecClass
  59  *
  60  * Casts a derived #GParamSpecClass structure into a #GParamSpecClass structure.
  61  */
  62 #define G_PARAM_SPEC_CLASS(pclass)      (G_TYPE_CHECK_CLASS_CAST ((pclass), G_TYPE_PARAM, GParamSpecClass))
  63 /**
  64  * G_IS_PARAM_SPEC_CLASS:
  65  * @pclass: a #GParamSpecClass
  66  *
  67  * Checks whether @pclass "is a" valid #GParamSpecClass structure of type
  68  * %G_TYPE_PARAM or derived.
  69  */
  70 #define G_IS_PARAM_SPEC_CLASS(pclass)   (G_TYPE_CHECK_CLASS_TYPE ((pclass), G_TYPE_PARAM))
  71 /**
  72  * G_PARAM_SPEC_GET_CLASS:
  73  * @pspec: a valid #GParamSpec
  74  *
  75  * Retrieves the #GParamSpecClass of a #GParamSpec.
  76  */
  77 #define G_PARAM_SPEC_GET_CLASS(pspec)   (G_TYPE_INSTANCE_GET_CLASS ((pspec), G_TYPE_PARAM, GParamSpecClass))
  78
  79
  80 /* --- convenience macros --- */
  81 /**
  82  * G_PARAM_SPEC_TYPE:
  83  * @pspec: a valid #GParamSpec
  84  *
  85  * Retrieves the #GType of this @pspec.
  86  */
  87 #define G_PARAM_SPEC_TYPE(pspec)        (G_TYPE_FROM_INSTANCE (pspec))
  88 /**
  89  * G_PARAM_SPEC_TYPE_NAME:
  90  * @pspec: a valid #GParamSpec
  91  *
  92  * Retrieves the #GType name of this @pspec.
  93  */
  94 #define G_PARAM_SPEC_TYPE_NAME(pspec)   (g_type_name (G_PARAM_SPEC_TYPE (pspec)))
  95 /**
  96  * G_PARAM_SPEC_VALUE_TYPE:
  97  * @pspec: a valid #GParamSpec
  98  *
  99  * Retrieves the #GType to initialize a #GValue for this parameter.
 100  */
 101 #define G_PARAM_SPEC_VALUE_TYPE(pspec)  (G_PARAM_SPEC (pspec)->value_type)
 102 /**
 103  * G_VALUE_HOLDS_PARAM:
 104  * @value: a valid #GValue structure
 105  *
 106  * Checks whether the given #GValue can hold values derived from type %G_TYPE_PARAM.
 107  *
 108  * Returns: %TRUE on success.
 109  */
 110 #define G_VALUE_HOLDS_PARAM(value)      (G_TYPE_CHECK_VALUE_TYPE ((value), G_TYPE_PARAM))
 111
 112
 113 /* --- flags --- */
 114 /**
 115  * GParamFlags:
 116  * @G_PARAM_READABLE: the parameter is readable
 117  * @G_PARAM_WRITABLE: the parameter is writable
 118  * @G_PARAM_CONSTRUCT: the parameter will be set upon object construction
 119  * @G_PARAM_CONSTRUCT_ONLY: the parameter will only be set upon object construction
 120  * @G_PARAM_LAX_VALIDATION: upon parameter conversion (see g_param_value_convert())
 121  *  strict validation is not required
 122  * @G_PARAM_STATIC_NAME: the string used as name when constructing the
 123  *  parameter is guaranteed to remain valid and
 124  *  unmodified for the lifetime of the parameter.
 125  *  Since 2.8
 126  * @G_PARAM_STATIC_NICK: the string used as nick when constructing the
 127  *  parameter is guaranteed to remain valid and
 128  *  unmmodified for the lifetime of the parameter.
 129  *  Since 2.8
 130  * @G_PARAM_STATIC_BLURB: the string used as blurb when constructing the
 131  *  parameter is guaranteed to remain valid and
 132  *  unmodified for the lifetime of the parameter.
 133  *  Since 2.8
 134  * @G_PARAM_PRIVATE: internal
 135  * @G_PARAM_DEPRECATED: the parameter is deprecated and will be removed
 136  *  in a future version. A warning will be generated if it is used
 137  *  while running with G_ENABLE_DIAGNOSTIC=1.
 138  *  Since 2.26
 139  *
 140  * Through the #GParamFlags flag values, certain aspects of parameters
 141  * can be configured. See also #G_PARAM_READWRITE and #G_PARAM_STATIC_STRINGS.
 142  */
 143 typedef enum
 144 {
 145   G_PARAM_READABLE            = 1 << 0,
 146   G_PARAM_WRITABLE            = 1 << 1,
 147   G_PARAM_CONSTRUCT           = 1 << 2,
 148   G_PARAM_CONSTRUCT_ONLY      = 1 << 3,
 149   G_PARAM_LAX_VALIDATION      = 1 << 4,
 150   G_PARAM_STATIC_NAME         = 1 << 5,
 151 #ifndef G_DISABLE_DEPRECATED
 152   G_PARAM_PRIVATE             = G_PARAM_STATIC_NAME,
 153 #endif
 154   G_PARAM_STATIC_NICK         = 1 << 6,
 155   G_PARAM_STATIC_BLURB        = 1 << 7,
 156   /* User defined flags go up to 30 */
 157   G_PARAM_DEPRECATED          = 1 << 31
 158 } GParamFlags;
 159 /**
 160  * G_PARAM_READWRITE:
 161  *
 162  * #GParamFlags value alias for %G_PARAM_READABLE | %G_PARAM_WRITABLE.
 163  */
 164 #define G_PARAM_READWRITE       (G_PARAM_READABLE | G_PARAM_WRITABLE)
 165 /**
 166  * G_PARAM_STATIC_STRINGS:
 167  *
 168  * #GParamFlags value alias for %G_PARAM_STATIC_NAME | %G_PARAM_STATIC_NICK | %G_PARAM_STATIC_BLURB.
 169  *
 170  * Since 2.13.0
 171  */
 172 #define G_PARAM_STATIC_STRINGS (G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB)
 173 /* bits in the range 0xffffff00 are reserved for 3rd party usage */
 174 /**
 175  * G_PARAM_MASK:
 176  *
 177  * Mask containing the bits of #GParamSpec.flags which are reserved for GLib.
 178  */
 179 #define G_PARAM_MASK            (0x000000ff)
 180 /**
 181  * G_PARAM_USER_SHIFT:
 182  *
 183  * Minimum shift count to be used for user defined flags, to be stored in
 184  * #GParamSpec.flags. The maximum allowed is 30 + G_PARAM_USER_SHIFT.
 185  */
 186 #define G_PARAM_USER_SHIFT      (8)
 187
 188 /* --- typedefs & structures --- */
 189 typedef struct _GParamSpec      GParamSpec;
 190 typedef struct _GParamSpecClass GParamSpecClass;
 191 typedef struct _GParameter      GParameter;
 192 typedef struct _GParamSpecPool  GParamSpecPool;
 193 /**
 194  * GParamSpec:
 195  * @g_type_instance: private #GTypeInstance portion
 196  * @name: name of this parameter: always an interned string
 197  * @flags: #GParamFlags flags for this parameter
 198  * @value_type: the #GValue type for this parameter
 199  * @owner_type: #GType type that uses (introduces) this parameter
 200  *
 201  * All other fields of the <structname>GParamSpec</structname> struct are private and
 202  * should not be used directly.
 203  */
 204 struct _GParamSpec
 205 {
 206   GTypeInstance  g_type_instance;
 207
 208   const gchar   *name;          /* interned string */
 209   GParamFlags    flags;
 210   GType          value_type;
 211   GType          owner_type;    /* class or interface using this property */
 212
 213   /*< private >*/
 214   gchar         *_nick;
 215   gchar         *_blurb;
 216   GData         *qdata;
 217   guint          ref_count;
 218   guint          param_id;      /* sort-criteria */
 219 };
 220 /**
 221  * GParamSpecClass:
 222  * @g_type_class: the parent class
 223  * @value_type: the #GValue type for this parameter
 224  * @finalize: The instance finalization function (optional), should chain
 225  *  up to the finalize method of the parent class.
 226  * @value_set_default: Resets a @value to the default value for this type
 227  *  (recommended, the default is g_value_reset()), see
 228  *  g_param_value_set_default().
 229  * @value_validate: Ensures that the contents of @value comply with the
 230  *  specifications set out by this type (optional), see
 231  *  g_param_value_validate().
 232  * @values_cmp: Compares @value1 with @value2 according to this type
 233  *  (recommended, the default is memcmp()), see g_param_values_cmp().
 234  *
 235  * The class structure for the <structname>GParamSpec</structname> type.
 236  * Normally, <structname>GParamSpec</structname> classes are filled by
 237  * g_param_type_register_static().
 238  */
 239 struct _GParamSpecClass
 240 {
 241   GTypeClass      g_type_class;
 242
 243   GType           value_type;
 244
 245   void          (*finalize)             (GParamSpec   *pspec);
 246
 247   /* GParam methods */
 248   void          (*value_set_default)    (GParamSpec   *pspec,
 249                                          GValue       *value);
 250   gboolean      (*value_validate)       (GParamSpec   *pspec,
 251                                          GValue       *value);
 252   gint          (*values_cmp)           (GParamSpec   *pspec,
 253                                          const GValue *value1,
 254                                          const GValue *value2);
 255   /*< private >*/
 256   gpointer        dummy[4];
 257 };
 258 /**
 259  * GParameter:
 260  * @name: the parameter name
 261  * @value: the parameter value
 262  *
 263  * The <structname>GParameter</structname> struct is an auxiliary structure used
 264  * to hand parameter name/value pairs to g_object_newv().
 265  */
 266 struct _GParameter /* auxiliary structure for _setv() variants */
 267 {
 268   const gchar *name;
 269   GValue       value;
 270 };
 271
 272
 273 /* --- prototypes --- */
 274 GLIB_AVAILABLE_IN_ALL
 275 GParamSpec*     g_param_spec_ref                (GParamSpec    *pspec);
 276 GLIB_AVAILABLE_IN_ALL
 277 void            g_param_spec_unref              (GParamSpec    *pspec);
 278 GLIB_AVAILABLE_IN_ALL
 279 void            g_param_spec_sink               (GParamSpec    *pspec);
 280 GLIB_AVAILABLE_IN_ALL
 281 GParamSpec*     g_param_spec_ref_sink           (GParamSpec    *pspec);
 282 GLIB_AVAILABLE_IN_ALL
 283 gpointer        g_param_spec_get_qdata          (GParamSpec    *pspec,
 284                                                  GQuark         quark);
 285 GLIB_AVAILABLE_IN_ALL
 286 void            g_param_spec_set_qdata          (GParamSpec    *pspec,
 287                                                  GQuark         quark,
 288                                                  gpointer       data);
 289 GLIB_AVAILABLE_IN_ALL
 290 void            g_param_spec_set_qdata_full     (GParamSpec    *pspec,
 291                                                  GQuark         quark,
 292                                                  gpointer       data,
 293                                                  GDestroyNotify destroy);
 294 GLIB_AVAILABLE_IN_ALL
 295 gpointer        g_param_spec_steal_qdata        (GParamSpec    *pspec,
 296                                                  GQuark         quark);
 297 GLIB_AVAILABLE_IN_ALL
 298 GParamSpec*     g_param_spec_get_redirect_target (GParamSpec   *pspec);
 299
 300 GLIB_AVAILABLE_IN_ALL
 301 void            g_param_value_set_default       (GParamSpec    *pspec,
 302                                                  GValue        *value);
 303 GLIB_AVAILABLE_IN_ALL
 304 gboolean        g_param_value_defaults          (GParamSpec    *pspec,
 305                                                  GValue        *value);
 306 GLIB_AVAILABLE_IN_ALL
 307 gboolean        g_param_value_validate          (GParamSpec    *pspec,
 308                                                  GValue        *value);
 309 GLIB_AVAILABLE_IN_ALL
 310 gboolean        g_param_value_convert           (GParamSpec    *pspec,
 311                                                  const GValue  *src_value,
 312                                                  GValue        *dest_value,
 313                                                  gboolean       strict_validation);
 314 GLIB_AVAILABLE_IN_ALL
 315 gint            g_param_values_cmp              (GParamSpec    *pspec,
 316                                                  const GValue  *value1,
 317                                                  const GValue  *value2);
 318 GLIB_AVAILABLE_IN_ALL
 319 const gchar *   g_param_spec_get_name           (GParamSpec    *pspec);
 320 GLIB_AVAILABLE_IN_ALL
 321 const gchar *   g_param_spec_get_nick           (GParamSpec    *pspec);
 322 GLIB_AVAILABLE_IN_ALL
 323 const gchar *   g_param_spec_get_blurb          (GParamSpec    *pspec);
 324 GLIB_AVAILABLE_IN_ALL
 325 void            g_value_set_param               (GValue        *value,
 326                                                  GParamSpec    *param);
 327 GLIB_AVAILABLE_IN_ALL
 328 GParamSpec*     g_value_get_param               (const GValue  *value);
 329 GLIB_AVAILABLE_IN_ALL
 330 GParamSpec*     g_value_dup_param               (const GValue  *value);
 331
 332
 333 GLIB_AVAILABLE_IN_ALL
 334 void           g_value_take_param               (GValue        *value,
 335                                                  GParamSpec    *param);
 336 GLIB_DEPRECATED_FOR(g_value_take_param)
 337 void           g_value_set_param_take_ownership (GValue        *value,
 338                                                  GParamSpec    *param);
 339 GLIB_AVAILABLE_IN_2_36
 340 const GValue *  g_param_spec_get_default_value  (GParamSpec     *param);
 341
 342 /* --- convenience functions --- */
 343 typedef struct _GParamSpecTypeInfo GParamSpecTypeInfo;
 344 /**
 345  * GParamSpecTypeInfo:
 346  * @instance_size: Size of the instance (object) structure.
 347  * @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.
 348  * @instance_init: Location of the instance initialization function (optional).
 349  * @value_type: The #GType of values conforming to this #GParamSpec
 350  * @finalize: The instance finalization function (optional).
 351  * @value_set_default: Resets a @value to the default value for @pspec
 352  *  (recommended, the default is g_value_reset()), see
 353  *  g_param_value_set_default().
 354  * @value_validate: Ensures that the contents of @value comply with the
 355  *  specifications set out by @pspec (optional), see
 356  *  g_param_value_validate().
 357  * @values_cmp: Compares @value1 with @value2 according to @pspec
 358  *  (recommended, the default is memcmp()), see g_param_values_cmp().
 359  *
 360  * This structure is used to provide the type system with the information
 361  * required to initialize and destruct (finalize) a parameter's class and
 362  * instances thereof.
 363  * The initialized structure is passed to the g_param_type_register_static()
 364  * The type system will perform a deep copy of this structure, so its memory
 365  * does not need to be persistent across invocation of
 366  * g_param_type_register_static().
 367  */
 368 struct _GParamSpecTypeInfo
 369 {
 370   /* type system portion */
 371   guint16         instance_size;                               /* obligatory */
 372   guint16         n_preallocs;                                 /* optional */
 373   void          (*instance_init)        (GParamSpec   *pspec); /* optional */
 374
 375   /* class portion */
 376   GType           value_type;                                  /* obligatory */
 377   void          (*finalize)             (GParamSpec   *pspec); /* optional */
 378   void          (*value_set_default)    (GParamSpec   *pspec,  /* recommended */
 379                                          GValue       *value);
 380   gboolean      (*value_validate)       (GParamSpec   *pspec,  /* optional */
 381                                          GValue       *value);
 382   gint          (*values_cmp)           (GParamSpec   *pspec,  /* recommended */
 383                                          const GValue *value1,
 384                                          const GValue *value2);
 385 };
 386 GLIB_AVAILABLE_IN_ALL
 387 GType   g_param_type_register_static    (const gchar              *name,
 388                                          const GParamSpecTypeInfo *pspec_info);
 389
 390 /* For registering builting types */
 391 GType  _g_param_type_register_static_constant (const gchar              *name,
 392                                                const GParamSpecTypeInfo *pspec_info,
 393                                                GType                     opt_type);
 394
 395
 396 /* --- protected --- */
 397 GLIB_AVAILABLE_IN_ALL
 398 gpointer        g_param_spec_internal           (GType          param_type,
 399                                                  const gchar   *name,
 400                                                  const gchar   *nick,
 401                                                  const gchar   *blurb,
 402                                                  GParamFlags    flags);
 403 GLIB_AVAILABLE_IN_ALL
 404 GParamSpecPool* g_param_spec_pool_new           (gboolean       type_prefixing);
 405 GLIB_AVAILABLE_IN_ALL
 406 void            g_param_spec_pool_insert        (GParamSpecPool *pool,
 407                                                  GParamSpec     *pspec,
 408                                                  GType           owner_type);
 409 GLIB_AVAILABLE_IN_ALL
 410 void            g_param_spec_pool_remove        (GParamSpecPool *pool,
 411                                                  GParamSpec     *pspec);
 412 GLIB_AVAILABLE_IN_ALL
 413 GParamSpec*     g_param_spec_pool_lookup        (GParamSpecPool *pool,
 414                                                  const gchar    *param_name,
 415                                                  GType           owner_type,
 416                                                  gboolean        walk_ancestors);
 417 GLIB_AVAILABLE_IN_ALL
 418 GList*          g_param_spec_pool_list_owned    (GParamSpecPool *pool,
 419                                                  GType           owner_type);
 420 GLIB_AVAILABLE_IN_ALL
 421 GParamSpec**    g_param_spec_pool_list          (GParamSpecPool *pool,
 422                                                  GType           owner_type,
 423                                                  guint          *n_pspecs_p);
 424
 425
 426 /* contracts:
 427  *
 428  * gboolean value_validate (GParamSpec *pspec,
 429  *                          GValue     *value):
 430  *      modify value contents in the least destructive way, so
 431  *      that it complies with pspec's requirements (i.e.
 432  *      according to minimum/maximum ranges etc...). return
 433  *      whether modification was necessary.
 434  *
 435  * gint values_cmp (GParamSpec   *pspec,
 436  *                  const GValue *value1,
 437  *                  const GValue *value2):
 438  *      return value1 - value2, i.e. (-1) if value1 < value2,
 439  *      (+1) if value1 > value2, and (0) otherwise (equality)
 440  */
 441
 442 G_END_DECLS
 443
 444 #endif /* __G_PARAM_H__ */