glib/gobject/gparam.h
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0:e4d67989cc36 18:47c74d1534e1
       
     1 /* GObject - GLib Type, Object, Parameter and Signal Library
       
     2  * Copyright (C) 1997-1999, 2000-2001 Tim Janik and Red Hat, Inc.
       
     3  * Portions copyright (c) 2006-2009 Nokia Corporation.  All rights reserved.
       
     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 #if !defined (__GLIB_GOBJECT_H_INSIDE__) && !defined (GOBJECT_COMPILATION)
       
    22 #error "Only <glib-object.h> can be included directly."
       
    23 #endif
       
    24 
       
    25 #ifndef __G_PARAM_H__
       
    26 #define __G_PARAM_H__
       
    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  * 
       
   136  * Through the #GParamFlags flag values, certain aspects of parameters
       
   137  * can be configured.
       
   138  */
       
   139 typedef enum
       
   140 {
       
   141   G_PARAM_READABLE            = 1 << 0,
       
   142   G_PARAM_WRITABLE            = 1 << 1,
       
   143   G_PARAM_CONSTRUCT	      = 1 << 2,
       
   144   G_PARAM_CONSTRUCT_ONLY      = 1 << 3,
       
   145   G_PARAM_LAX_VALIDATION      = 1 << 4,
       
   146   G_PARAM_STATIC_NAME	      = 1 << 5,
       
   147 #ifndef G_DISABLE_DEPRECATED
       
   148   G_PARAM_PRIVATE	      = G_PARAM_STATIC_NAME,
       
   149 #endif
       
   150   G_PARAM_STATIC_NICK	      = 1 << 6,
       
   151   G_PARAM_STATIC_BLURB	      = 1 << 7
       
   152 } GParamFlags;
       
   153 /**
       
   154  * G_PARAM_READWRITE:
       
   155  * 
       
   156  * #GParamFlags value alias for %G_PARAM_READABLE | %G_PARAM_WRITABLE.
       
   157  */
       
   158 #define	G_PARAM_READWRITE	(G_PARAM_READABLE | G_PARAM_WRITABLE)
       
   159 /**
       
   160  * G_PARAM_STATIC_STRINGS:
       
   161  * 
       
   162  * #GParamFlags value alias for %G_PARAM_STATIC_NAME | %G_PARAM_STATIC_NICK | %G_PARAM_STATIC_BLURB.
       
   163  * 
       
   164  * Since 2.13.0
       
   165  */
       
   166 #define	G_PARAM_STATIC_STRINGS (G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB)
       
   167 /* bits in the range 0xffffff00 are reserved for 3rd party usage */
       
   168 /**
       
   169  * G_PARAM_MASK:
       
   170  * 
       
   171  * Mask containing the bits of #GParamSpec.flags which are reserved for GLib.
       
   172  */
       
   173 #define	G_PARAM_MASK		(0x000000ff)
       
   174 /**
       
   175  * G_PARAM_USER_SHIFT:
       
   176  * 
       
   177  * Minimum shift count to be used for user defined flags, to be stored in
       
   178  * #GParamSpec.flags.
       
   179  */
       
   180 #define	G_PARAM_USER_SHIFT	(8)
       
   181 
       
   182 
       
   183 /* --- typedefs & structures --- */
       
   184 typedef struct _GParamSpec      GParamSpec;
       
   185 typedef struct _GParamSpecClass GParamSpecClass;
       
   186 typedef struct _GParameter	GParameter;
       
   187 typedef struct _GParamSpecPool  GParamSpecPool;
       
   188 /**
       
   189  * GParamSpec:
       
   190  * @g_type_instance: private #GTypeInstance portion
       
   191  * @name: name of this parameter
       
   192  * @flags: #GParamFlags flags for this parameter
       
   193  * @value_type: the #GValue type for this parameter
       
   194  * @owner_type: #GType type that uses (introduces) this paremeter
       
   195  * 
       
   196  * All other fields of the <structname>GParamSpec</structname> struct are private and
       
   197  * should not be used directly.
       
   198  */
       
   199 struct _GParamSpec
       
   200 {
       
   201   GTypeInstance  g_type_instance;
       
   202 
       
   203   gchar         *name;
       
   204   GParamFlags    flags;
       
   205   GType		 value_type;
       
   206   GType		 owner_type;	/* class or interface using this property */
       
   207 
       
   208   /*< private >*/
       
   209   gchar         *_nick;
       
   210   gchar         *_blurb;
       
   211   GData		*qdata;
       
   212   guint          ref_count;
       
   213   guint		 param_id;	/* sort-criteria */
       
   214 };
       
   215 /**
       
   216  * GParamSpecClass:
       
   217  * @g_type_class: the parent class
       
   218  * @value_type: the #GValue type for this parameter
       
   219  * @finalize: The instance finalization function (optional), should chain 
       
   220  *  up to the finalize method of the parent class.
       
   221  * @value_set_default: Resets a @value to the default value for this type
       
   222  *  (recommended, the default is g_value_reset()), see 
       
   223  *  g_param_value_set_default().
       
   224  * @value_validate: Ensures that the contents of @value comply with the 
       
   225  *  specifications set out by this type (optional), see 
       
   226  *  g_param_value_set_validate().
       
   227  * @values_cmp: Compares @value1 with @value2 according to this type
       
   228  *  (recommended, the default is memcmp()), see g_param_values_cmp().
       
   229  * 
       
   230  * The class structure for the <structname>GParamSpec</structname> type.
       
   231  * Normally, <structname>GParamSpec</structname> classes are filled by
       
   232  * g_param_type_register_static().
       
   233  */
       
   234 struct _GParamSpecClass
       
   235 {
       
   236   GTypeClass      g_type_class;
       
   237 
       
   238   GType		  value_type;
       
   239 
       
   240   void	        (*finalize)		(GParamSpec   *pspec);
       
   241 
       
   242   /* GParam methods */
       
   243   void          (*value_set_default)    (GParamSpec   *pspec,
       
   244 					 GValue       *value);
       
   245   gboolean      (*value_validate)       (GParamSpec   *pspec,
       
   246 					 GValue       *value);
       
   247   gint          (*values_cmp)           (GParamSpec   *pspec,
       
   248 					 const GValue *value1,
       
   249 					 const GValue *value2);
       
   250   /*< private >*/
       
   251   gpointer	  dummy[4];
       
   252 };
       
   253 /**
       
   254  * GParameter:
       
   255  * @name: the parameter name
       
   256  * @value: the parameter value
       
   257  * 
       
   258  * The <structname>GParameter</structname> struct is an auxiliary structure used
       
   259  * to hand parameter name/value pairs to g_object_newv().
       
   260  */
       
   261 struct _GParameter /* auxillary structure for _setv() variants */
       
   262 {
       
   263   const gchar *name;
       
   264   GValue       value;
       
   265 };
       
   266 
       
   267 
       
   268 /* --- prototypes --- */
       
   269 IMPORT_C GParamSpec*	g_param_spec_ref		(GParamSpec    *pspec);
       
   270 IMPORT_C void		g_param_spec_unref		(GParamSpec    *pspec);
       
   271 IMPORT_C void		g_param_spec_sink		(GParamSpec    *pspec);
       
   272 IMPORT_C GParamSpec*	g_param_spec_ref_sink   	(GParamSpec    *pspec);
       
   273 IMPORT_C gpointer        g_param_spec_get_qdata		(GParamSpec    *pspec,
       
   274 						 GQuark         quark);
       
   275 IMPORT_C void            g_param_spec_set_qdata		(GParamSpec    *pspec,
       
   276 						 GQuark         quark,
       
   277 						 gpointer       data);
       
   278 IMPORT_C void            g_param_spec_set_qdata_full	(GParamSpec    *pspec,
       
   279 						 GQuark         quark,
       
   280 						 gpointer       data,
       
   281 						 GDestroyNotify destroy);
       
   282 IMPORT_C gpointer        g_param_spec_steal_qdata	(GParamSpec    *pspec,
       
   283 						 GQuark         quark);
       
   284 IMPORT_C GParamSpec*     g_param_spec_get_redirect_target (GParamSpec   *pspec);
       
   285 
       
   286 IMPORT_C void		g_param_value_set_default	(GParamSpec    *pspec,
       
   287 						 GValue	       *value);
       
   288 IMPORT_C gboolean	g_param_value_defaults		(GParamSpec    *pspec,
       
   289 						 GValue	       *value);
       
   290 IMPORT_C gboolean	g_param_value_validate		(GParamSpec    *pspec,
       
   291 						 GValue	       *value);
       
   292 IMPORT_C gboolean	g_param_value_convert		(GParamSpec    *pspec,
       
   293 						 const GValue  *src_value,
       
   294 						 GValue	       *dest_value,
       
   295 						 gboolean	strict_validation);
       
   296 IMPORT_C gint		g_param_values_cmp		(GParamSpec    *pspec,
       
   297 						 const GValue  *value1,
       
   298 						 const GValue  *value2);
       
   299 IMPORT_C G_CONST_RETURN gchar*	g_param_spec_get_name	(GParamSpec    *pspec);
       
   300 IMPORT_C G_CONST_RETURN gchar*	g_param_spec_get_nick	(GParamSpec    *pspec);
       
   301 IMPORT_C G_CONST_RETURN gchar*	g_param_spec_get_blurb	(GParamSpec    *pspec);
       
   302 IMPORT_C void            g_value_set_param               (GValue	       *value,
       
   303 						 GParamSpec    *param);
       
   304 IMPORT_C GParamSpec*     g_value_get_param               (const GValue  *value);
       
   305 IMPORT_C GParamSpec*     g_value_dup_param               (const GValue  *value);
       
   306 
       
   307 
       
   308 IMPORT_C void           g_value_take_param               (GValue        *value,
       
   309 					         GParamSpec    *param);
       
   310 #ifndef G_DISABLE_DEPRECATED
       
   311 IMPORT_C void           g_value_set_param_take_ownership (GValue        *value,
       
   312 					         GParamSpec    *param);
       
   313 #endif
       
   314 
       
   315 /* --- convenience functions --- */
       
   316 typedef struct _GParamSpecTypeInfo GParamSpecTypeInfo;
       
   317 /**
       
   318  * GParamSpecTypeInfo:
       
   319  * @instance_size: Size of the instance (object) structure.
       
   320  * @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.
       
   321  * @instance_init: Location of the instance initialization function (optional).
       
   322  * @value_type: The #GType of values conforming to this #GParamSpec
       
   323  * @finalize: The instance finalization function (optional).
       
   324  * @value_set_default: Resets a @value to the default value for @pspec 
       
   325  *  (recommended, the default is g_value_reset()), see 
       
   326  *  g_param_value_set_default().
       
   327  * @value_validate: Ensures that the contents of @value comply with the 
       
   328  *  specifications set out by @pspec (optional), see 
       
   329  *  g_param_value_set_validate().
       
   330  * @values_cmp: Compares @value1 with @value2 according to @pspec 
       
   331  *  (recommended, the default is memcmp()), see g_param_values_cmp().
       
   332  * 
       
   333  * This structure is used to provide the type system with the information
       
   334  * required to initialize and destruct (finalize) a parameter's class and
       
   335  * instances thereof.
       
   336  * The initialized structure is passed to the g_param_type_register_static() 
       
   337  * The type system will perform a deep copy of this structure, so its memory 
       
   338  * does not need to be persistent across invocation of 
       
   339  * g_param_type_register_static().
       
   340  */
       
   341 struct _GParamSpecTypeInfo
       
   342 {
       
   343   /* type system portion */
       
   344   guint16         instance_size;                               /* obligatory */
       
   345   guint16         n_preallocs;                                 /* optional */
       
   346   void		(*instance_init)	(GParamSpec   *pspec); /* optional */
       
   347 
       
   348   /* class portion */
       
   349   GType           value_type;				       /* obligatory */
       
   350   void          (*finalize)             (GParamSpec   *pspec); /* optional */
       
   351   void          (*value_set_default)    (GParamSpec   *pspec,  /* recommended */
       
   352 					 GValue       *value);
       
   353   gboolean      (*value_validate)       (GParamSpec   *pspec,  /* optional */
       
   354 					 GValue       *value);
       
   355   gint          (*values_cmp)           (GParamSpec   *pspec,  /* recommended */
       
   356 					 const GValue *value1,
       
   357 					 const GValue *value2);
       
   358 };
       
   359 IMPORT_C GType	g_param_type_register_static	(const gchar		  *name,
       
   360 					 const GParamSpecTypeInfo *pspec_info);
       
   361 
       
   362 /* For registering builting types */
       
   363 GType  _g_param_type_register_static_constant (const gchar              *name,
       
   364 					       const GParamSpecTypeInfo *pspec_info,
       
   365 					       GType                     opt_type);
       
   366 
       
   367 
       
   368 /* --- protected --- */
       
   369 IMPORT_C gpointer	g_param_spec_internal		(GType	        param_type,
       
   370 						 const gchar   *name,
       
   371 						 const gchar   *nick,
       
   372 						 const gchar   *blurb,
       
   373 						 GParamFlags    flags);
       
   374 IMPORT_C GParamSpecPool* g_param_spec_pool_new		(gboolean	type_prefixing);
       
   375 IMPORT_C void		g_param_spec_pool_insert	(GParamSpecPool	*pool,
       
   376 						 GParamSpec	*pspec,
       
   377 						 GType		 owner_type);
       
   378 IMPORT_C void		g_param_spec_pool_remove	(GParamSpecPool	*pool,
       
   379 						 GParamSpec	*pspec);
       
   380 IMPORT_C GParamSpec*	g_param_spec_pool_lookup	(GParamSpecPool	*pool,
       
   381 						 const gchar	*param_name,
       
   382 						 GType		 owner_type,
       
   383 						 gboolean	 walk_ancestors);
       
   384 IMPORT_C GList*		g_param_spec_pool_list_owned	(GParamSpecPool	*pool,
       
   385 						 GType		 owner_type);
       
   386 IMPORT_C GParamSpec**	g_param_spec_pool_list		(GParamSpecPool	*pool,
       
   387 						 GType		 owner_type,
       
   388 						 guint		*n_pspecs_p);
       
   389 
       
   390 
       
   391 
       
   392 /* contracts:
       
   393  *
       
   394  * gboolean value_validate (GParamSpec *pspec,
       
   395  *                          GValue     *value):
       
   396  *	modify value contents in the least destructive way, so
       
   397  *	that it complies with pspec's requirements (i.e.
       
   398  *	according to minimum/maximum ranges etc...). return
       
   399  *	whether modification was necessary.
       
   400  *
       
   401  * gint values_cmp (GParamSpec   *pspec,
       
   402  *                  const GValue *value1,
       
   403  *                  const GValue *value2):
       
   404  *	return value1 - value2, i.e. (-1) if value1 < value2,
       
   405  *	(+1) if value1 > value2, and (0) otherwise (equality)
       
   406  */
       
   407 
       
   408 G_END_DECLS
       
   409 
       
   410 #endif /* __G_PARAM_H__ */