glib/gobject/gparam.h
Philip Withnall 8f9c5090db docs: Use G_PARAM_STATIC_STRINGS in examples and explain it more
Make it a bit clearer in the documentation that using
`G_PARAM_STATIC_STRINGS` everywhere is a good thing.

Signed-off-by: Philip Withnall <pwithnall@endlessos.org>
2022-05-20 12:57:36 +01:00

465 lines
16 KiB
C

/* GObject - GLib Type, Object, Parameter and Signal Library
* Copyright (C) 1997-1999, 2000-2001 Tim Janik and Red Hat, Inc.
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) any later version.
*
* This library is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General
* Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
*
* gparam.h: GParamSpec base class implementation
*/
#ifndef __G_PARAM_H__
#define __G_PARAM_H__
#if !defined (__GLIB_GOBJECT_H_INSIDE__) && !defined (GOBJECT_COMPILATION)
#error "Only <glib-object.h> can be included directly."
#endif
#include <gobject/gvalue.h>
G_BEGIN_DECLS
/* --- standard type macros --- */
/**
* G_TYPE_IS_PARAM:
* @type: a #GType ID
*
* Checks whether @type "is a" %G_TYPE_PARAM.
*/
#define G_TYPE_IS_PARAM(type) (G_TYPE_FUNDAMENTAL (type) == G_TYPE_PARAM)
/**
* G_PARAM_SPEC:
* @pspec: a valid #GParamSpec
*
* Casts a derived #GParamSpec object (e.g. of type #GParamSpecInt) into
* a #GParamSpec object.
*/
#define G_PARAM_SPEC(pspec) (G_TYPE_CHECK_INSTANCE_CAST ((pspec), G_TYPE_PARAM, GParamSpec))
/**
* G_IS_PARAM_SPEC:
* @pspec: a #GParamSpec
*
* Checks whether @pspec "is a" valid #GParamSpec structure of type %G_TYPE_PARAM
* or derived.
*/
#if GLIB_VERSION_MAX_ALLOWED >= GLIB_VERSION_2_42
#define G_IS_PARAM_SPEC(pspec) (G_TYPE_CHECK_INSTANCE_FUNDAMENTAL_TYPE ((pspec), G_TYPE_PARAM))
#else
#define G_IS_PARAM_SPEC(pspec) (G_TYPE_CHECK_INSTANCE_TYPE ((pspec), G_TYPE_PARAM))
#endif
/**
* G_PARAM_SPEC_CLASS:
* @pclass: a valid #GParamSpecClass
*
* Casts a derived #GParamSpecClass structure into a #GParamSpecClass structure.
*/
#define G_PARAM_SPEC_CLASS(pclass) (G_TYPE_CHECK_CLASS_CAST ((pclass), G_TYPE_PARAM, GParamSpecClass))
/**
* G_IS_PARAM_SPEC_CLASS:
* @pclass: a #GParamSpecClass
*
* Checks whether @pclass "is a" valid #GParamSpecClass structure of type
* %G_TYPE_PARAM or derived.
*/
#define G_IS_PARAM_SPEC_CLASS(pclass) (G_TYPE_CHECK_CLASS_TYPE ((pclass), G_TYPE_PARAM))
/**
* G_PARAM_SPEC_GET_CLASS:
* @pspec: a valid #GParamSpec
*
* Retrieves the #GParamSpecClass of a #GParamSpec.
*/
#define G_PARAM_SPEC_GET_CLASS(pspec) (G_TYPE_INSTANCE_GET_CLASS ((pspec), G_TYPE_PARAM, GParamSpecClass))
/* --- convenience macros --- */
/**
* G_PARAM_SPEC_TYPE:
* @pspec: a valid #GParamSpec
*
* Retrieves the #GType of this @pspec.
*/
#define G_PARAM_SPEC_TYPE(pspec) (G_TYPE_FROM_INSTANCE (pspec))
/**
* G_PARAM_SPEC_TYPE_NAME:
* @pspec: a valid #GParamSpec
*
* Retrieves the #GType name of this @pspec.
*/
#define G_PARAM_SPEC_TYPE_NAME(pspec) (g_type_name (G_PARAM_SPEC_TYPE (pspec)))
/**
* G_PARAM_SPEC_VALUE_TYPE:
* @pspec: a valid #GParamSpec
*
* Retrieves the #GType to initialize a #GValue for this parameter.
*/
#define G_PARAM_SPEC_VALUE_TYPE(pspec) (G_PARAM_SPEC (pspec)->value_type)
/**
* G_VALUE_HOLDS_PARAM:
* @value: a valid #GValue structure
*
* Checks whether the given #GValue can hold values derived from type %G_TYPE_PARAM.
*
* Returns: %TRUE on success.
*/
#define G_VALUE_HOLDS_PARAM(value) (G_TYPE_CHECK_VALUE_TYPE ((value), G_TYPE_PARAM))
/* --- flags --- */
/**
* GParamFlags:
* @G_PARAM_READABLE: the parameter is readable
* @G_PARAM_WRITABLE: the parameter is writable
* @G_PARAM_READWRITE: alias for %G_PARAM_READABLE | %G_PARAM_WRITABLE
* @G_PARAM_CONSTRUCT: the parameter will be set upon object construction
* @G_PARAM_CONSTRUCT_ONLY: the parameter can only be set upon object construction
* @G_PARAM_LAX_VALIDATION: upon parameter conversion (see g_param_value_convert())
* strict validation is not required
* @G_PARAM_STATIC_NAME: the string used as name when constructing the
* parameter is guaranteed to remain valid and
* unmodified for the lifetime of the parameter.
* Since 2.8
* @G_PARAM_STATIC_NICK: the string used as nick when constructing the
* parameter is guaranteed to remain valid and
* unmmodified for the lifetime of the parameter.
* Since 2.8
* @G_PARAM_STATIC_BLURB: the string used as blurb when constructing the
* parameter is guaranteed to remain valid and
* unmodified for the lifetime of the parameter.
* Since 2.8
* @G_PARAM_EXPLICIT_NOTIFY: calls to g_object_set_property() for this
* property will not automatically result in a "notify" signal being
* emitted: the implementation must call g_object_notify() themselves
* in case the property actually changes. Since: 2.42.
* @G_PARAM_PRIVATE: internal
* @G_PARAM_DEPRECATED: the parameter is deprecated and will be removed
* in a future version. A warning will be generated if it is used
* while running with G_ENABLE_DIAGNOSTIC=1.
* Since 2.26
*
* Through the #GParamFlags flag values, certain aspects of parameters
* can be configured.
*
* See also: %G_PARAM_STATIC_STRINGS
*/
typedef enum
{
G_PARAM_READABLE = 1 << 0,
G_PARAM_WRITABLE = 1 << 1,
G_PARAM_READWRITE = (G_PARAM_READABLE | G_PARAM_WRITABLE),
G_PARAM_CONSTRUCT = 1 << 2,
G_PARAM_CONSTRUCT_ONLY = 1 << 3,
G_PARAM_LAX_VALIDATION = 1 << 4,
G_PARAM_STATIC_NAME = 1 << 5,
G_PARAM_PRIVATE GLIB_DEPRECATED_ENUMERATOR_IN_2_26 = G_PARAM_STATIC_NAME,
G_PARAM_STATIC_NICK = 1 << 6,
G_PARAM_STATIC_BLURB = 1 << 7,
/* User defined flags go here */
G_PARAM_EXPLICIT_NOTIFY = 1 << 30,
/* Avoid warning with -Wpedantic for gcc6 */
G_PARAM_DEPRECATED = (gint)(1u << 31)
} GParamFlags;
/**
* G_PARAM_STATIC_STRINGS:
*
* #GParamFlags value alias for %G_PARAM_STATIC_NAME | %G_PARAM_STATIC_NICK | %G_PARAM_STATIC_BLURB.
*
* It is recommended to use this for all properties by default, as it allows for
* internal performance improvements in GObject.
*
* It is very rare that a property would have a dynamically constructed name,
* nickname or blurb.
*
* Since 2.13.0
*/
#define G_PARAM_STATIC_STRINGS (G_PARAM_STATIC_NAME | G_PARAM_STATIC_NICK | G_PARAM_STATIC_BLURB)
/* bits in the range 0xffffff00 are reserved for 3rd party usage */
/**
* G_PARAM_MASK:
*
* Mask containing the bits of #GParamSpec.flags which are reserved for GLib.
*/
#define G_PARAM_MASK (0x000000ff)
/**
* G_PARAM_USER_SHIFT:
*
* Minimum shift count to be used for user defined flags, to be stored in
* #GParamSpec.flags. The maximum allowed is 10.
*/
#define G_PARAM_USER_SHIFT (8)
/* --- typedefs & structures --- */
typedef struct _GParamSpec GParamSpec;
typedef struct _GParamSpecClass GParamSpecClass;
typedef struct _GParameter GParameter GLIB_DEPRECATED_TYPE_IN_2_54;
typedef struct _GParamSpecPool GParamSpecPool;
/**
* GParamSpec: (ref-func g_param_spec_ref_sink) (unref-func g_param_spec_unref) (set-value-func g_value_set_param) (get-value-func g_value_get_param)
* @g_type_instance: private #GTypeInstance portion
* @name: name of this parameter: always an interned string
* @flags: #GParamFlags flags for this parameter
* @value_type: the #GValue type for this parameter
* @owner_type: #GType type that uses (introduces) this parameter
*
* All other fields of the GParamSpec struct are private and
* should not be used directly.
*/
struct _GParamSpec
{
GTypeInstance g_type_instance;
const gchar *name; /* interned string */
GParamFlags flags;
GType value_type;
GType owner_type; /* class or interface using this property */
/*< private >*/
gchar *_nick;
gchar *_blurb;
GData *qdata;
guint ref_count;
guint param_id; /* sort-criteria */
};
/**
* GParamSpecClass:
* @g_type_class: the parent class
* @value_type: the #GValue type for this parameter
* @finalize: The instance finalization function (optional), should chain
* up to the finalize method of the parent class.
* @value_set_default: Resets a @value to the default value for this type
* (recommended, the default is g_value_reset()), see
* g_param_value_set_default().
* @value_validate: Ensures that the contents of @value comply with the
* specifications set out by this type (optional), see
* g_param_value_validate().
* @values_cmp: Compares @value1 with @value2 according to this type
* (recommended, the default is memcmp()), see g_param_values_cmp().
*
* The class structure for the GParamSpec type.
* Normally, GParamSpec classes are filled by
* g_param_type_register_static().
*/
struct _GParamSpecClass
{
GTypeClass g_type_class;
GType value_type;
void (*finalize) (GParamSpec *pspec);
/* GParam methods */
void (*value_set_default) (GParamSpec *pspec,
GValue *value);
gboolean (*value_validate) (GParamSpec *pspec,
GValue *value);
gint (*values_cmp) (GParamSpec *pspec,
const GValue *value1,
const GValue *value2);
/*< private >*/
gpointer dummy[4];
};
/**
* GParameter:
* @name: the parameter name
* @value: the parameter value
*
* The GParameter struct is an auxiliary structure used
* to hand parameter name/value pairs to g_object_newv().
*
* Deprecated: 2.54: This type is not introspectable.
*/
struct _GParameter /* auxiliary structure for _setv() variants */
{
const gchar *name;
GValue value;
} GLIB_DEPRECATED_TYPE_IN_2_54;
/* --- prototypes --- */
GLIB_AVAILABLE_IN_ALL
GParamSpec* g_param_spec_ref (GParamSpec *pspec);
GLIB_AVAILABLE_IN_ALL
void g_param_spec_unref (GParamSpec *pspec);
GLIB_AVAILABLE_IN_ALL
void g_param_spec_sink (GParamSpec *pspec);
GLIB_AVAILABLE_IN_ALL
GParamSpec* g_param_spec_ref_sink (GParamSpec *pspec);
GLIB_AVAILABLE_IN_ALL
gpointer g_param_spec_get_qdata (GParamSpec *pspec,
GQuark quark);
GLIB_AVAILABLE_IN_ALL
void g_param_spec_set_qdata (GParamSpec *pspec,
GQuark quark,
gpointer data);
GLIB_AVAILABLE_IN_ALL
void g_param_spec_set_qdata_full (GParamSpec *pspec,
GQuark quark,
gpointer data,
GDestroyNotify destroy);
GLIB_AVAILABLE_IN_ALL
gpointer g_param_spec_steal_qdata (GParamSpec *pspec,
GQuark quark);
GLIB_AVAILABLE_IN_ALL
GParamSpec* g_param_spec_get_redirect_target (GParamSpec *pspec);
GLIB_AVAILABLE_IN_ALL
void g_param_value_set_default (GParamSpec *pspec,
GValue *value);
GLIB_AVAILABLE_IN_ALL
gboolean g_param_value_defaults (GParamSpec *pspec,
const GValue *value);
GLIB_AVAILABLE_IN_ALL
gboolean g_param_value_validate (GParamSpec *pspec,
GValue *value);
GLIB_AVAILABLE_IN_ALL
gboolean g_param_value_convert (GParamSpec *pspec,
const GValue *src_value,
GValue *dest_value,
gboolean strict_validation);
GLIB_AVAILABLE_IN_ALL
gint g_param_values_cmp (GParamSpec *pspec,
const GValue *value1,
const GValue *value2);
GLIB_AVAILABLE_IN_ALL
const gchar * g_param_spec_get_name (GParamSpec *pspec);
GLIB_AVAILABLE_IN_ALL
const gchar * g_param_spec_get_nick (GParamSpec *pspec);
GLIB_AVAILABLE_IN_ALL
const gchar * g_param_spec_get_blurb (GParamSpec *pspec);
GLIB_AVAILABLE_IN_ALL
void g_value_set_param (GValue *value,
GParamSpec *param);
GLIB_AVAILABLE_IN_ALL
GParamSpec* g_value_get_param (const GValue *value);
GLIB_AVAILABLE_IN_ALL
GParamSpec* g_value_dup_param (const GValue *value);
GLIB_AVAILABLE_IN_ALL
void g_value_take_param (GValue *value,
GParamSpec *param);
GLIB_DEPRECATED_FOR(g_value_take_param)
void g_value_set_param_take_ownership (GValue *value,
GParamSpec *param);
GLIB_AVAILABLE_IN_2_36
const GValue * g_param_spec_get_default_value (GParamSpec *pspec);
GLIB_AVAILABLE_IN_2_46
GQuark g_param_spec_get_name_quark (GParamSpec *pspec);
/* --- convenience functions --- */
typedef struct _GParamSpecTypeInfo GParamSpecTypeInfo;
/**
* GParamSpecTypeInfo:
* @instance_size: Size of the instance (object) structure.
* @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 [slice allocator][glib-Memory-Slices] now.
* @instance_init: Location of the instance initialization function (optional).
* @value_type: The #GType of values conforming to this #GParamSpec
* @finalize: The instance finalization function (optional).
* @value_set_default: Resets a @value to the default value for @pspec
* (recommended, the default is g_value_reset()), see
* g_param_value_set_default().
* @value_validate: Ensures that the contents of @value comply with the
* specifications set out by @pspec (optional), see
* g_param_value_validate().
* @values_cmp: Compares @value1 with @value2 according to @pspec
* (recommended, the default is memcmp()), see g_param_values_cmp().
*
* This structure is used to provide the type system with the information
* required to initialize and destruct (finalize) a parameter's class and
* instances thereof.
*
* The initialized structure is passed to the g_param_type_register_static()
* The type system will perform a deep copy of this structure, so its memory
* does not need to be persistent across invocation of
* g_param_type_register_static().
*/
struct _GParamSpecTypeInfo
{
/* type system portion */
guint16 instance_size; /* obligatory */
guint16 n_preallocs; /* optional */
void (*instance_init) (GParamSpec *pspec); /* optional */
/* class portion */
GType value_type; /* obligatory */
void (*finalize) (GParamSpec *pspec); /* optional */
void (*value_set_default) (GParamSpec *pspec, /* recommended */
GValue *value);
gboolean (*value_validate) (GParamSpec *pspec, /* optional */
GValue *value);
gint (*values_cmp) (GParamSpec *pspec, /* recommended */
const GValue *value1,
const GValue *value2);
};
GLIB_AVAILABLE_IN_ALL
GType g_param_type_register_static (const gchar *name,
const GParamSpecTypeInfo *pspec_info);
GLIB_AVAILABLE_IN_2_66
gboolean g_param_spec_is_valid_name (const gchar *name);
/* For registering builting types */
GType _g_param_type_register_static_constant (const gchar *name,
const GParamSpecTypeInfo *pspec_info,
GType opt_type);
/* --- protected --- */
GLIB_AVAILABLE_IN_ALL
gpointer g_param_spec_internal (GType param_type,
const gchar *name,
const gchar *nick,
const gchar *blurb,
GParamFlags flags);
GLIB_AVAILABLE_IN_ALL
GParamSpecPool* g_param_spec_pool_new (gboolean type_prefixing);
GLIB_AVAILABLE_IN_ALL
void g_param_spec_pool_insert (GParamSpecPool *pool,
GParamSpec *pspec,
GType owner_type);
GLIB_AVAILABLE_IN_ALL
void g_param_spec_pool_remove (GParamSpecPool *pool,
GParamSpec *pspec);
GLIB_AVAILABLE_IN_ALL
GParamSpec* g_param_spec_pool_lookup (GParamSpecPool *pool,
const gchar *param_name,
GType owner_type,
gboolean walk_ancestors);
GLIB_AVAILABLE_IN_ALL
GList* g_param_spec_pool_list_owned (GParamSpecPool *pool,
GType owner_type);
GLIB_AVAILABLE_IN_ALL
GParamSpec** g_param_spec_pool_list (GParamSpecPool *pool,
GType owner_type,
guint *n_pspecs_p);
/* contracts:
*
* gboolean value_validate (GParamSpec *pspec,
* GValue *value):
* modify value contents in the least destructive way, so
* that it complies with pspec's requirements (i.e.
* according to minimum/maximum ranges etc...). return
* whether modification was necessary.
*
* gint values_cmp (GParamSpec *pspec,
* const GValue *value1,
* const GValue *value2):
* return value1 - value2, i.e. (-1) if value1 < value2,
* (+1) if value1 > value2, and (0) otherwise (equality)
*/
G_END_DECLS
#endif /* __G_PARAM_H__ */