/* GObject - GLib Type, Object, Parameter and Signal Library
* Copyright (C) 1998-1999, 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/>.
*/
#ifndef __G_OBJECT_H__
#define __G_OBJECT_H__
#if !defined (__GLIB_GOBJECT_H_INSIDE__) && !defined (GOBJECT_COMPILATION)
#error "Only <glib-object.h> can be included directly."
#endif
#include <gobject/gtype.h>
#include <gobject/gvalue.h>
#include <gobject/gparam.h>
#include <gobject/gclosure.h>
#include <gobject/gsignal.h>
#include <gobject/gboxed.h>
G_BEGIN_DECLS
/* --- type macros --- */
/**
* G_TYPE_IS_OBJECT:
* @type: Type id to check
*
* Check if the passed in type id is a %G_TYPE_OBJECT or derived from it.
*
* Returns: %FALSE or %TRUE, indicating whether @type is a %G_TYPE_OBJECT.
*/
#define G_TYPE_IS_OBJECT(type) (G_TYPE_FUNDAMENTAL (type) == G_TYPE_OBJECT)
/**
* G_OBJECT:
* @object: Object which is subject to casting.
*
* Casts a #GObject or derived pointer into a (GObject*) pointer.
* Depending on the current debugging level, this function may invoke
* certain runtime checks to identify invalid casts.
*/
#define G_OBJECT(object) (G_TYPE_CHECK_INSTANCE_CAST ((object), G_TYPE_OBJECT, GObject))
/**
* G_OBJECT_CLASS:
* @class: a valid #GObjectClass
*
* Casts a derived #GObjectClass structure into a #GObjectClass structure.
*/
#define G_OBJECT_CLASS(class) (G_TYPE_CHECK_CLASS_CAST ((class), G_TYPE_OBJECT, GObjectClass))
/**
* G_IS_OBJECT:
* @object: Instance to check for being a %G_TYPE_OBJECT.
*
* Checks whether a valid #GTypeInstance pointer is of type %G_TYPE_OBJECT.
*/
#if GLIB_VERSION_MAX_ALLOWED >= GLIB_VERSION_2_42
#define G_IS_OBJECT(object) (G_TYPE_CHECK_INSTANCE_FUNDAMENTAL_TYPE ((object), G_TYPE_OBJECT))
#else
#define G_IS_OBJECT(object) (G_TYPE_CHECK_INSTANCE_TYPE ((object), G_TYPE_OBJECT))
#endif
/**
* G_IS_OBJECT_CLASS:
* @class: a #GObjectClass
*
* Checks whether @class "is a" valid #GObjectClass structure of type
* %G_TYPE_OBJECT or derived.
*/
#define G_IS_OBJECT_CLASS(class) (G_TYPE_CHECK_CLASS_TYPE ((class), G_TYPE_OBJECT))
/**
* G_OBJECT_GET_CLASS:
* @object: a #GObject instance.
*
* Get the class structure associated to a #GObject instance.
*
* Returns: pointer to object class structure.
*/
#define G_OBJECT_GET_CLASS(object) (G_TYPE_INSTANCE_GET_CLASS ((object), G_TYPE_OBJECT, GObjectClass))
/**
* G_OBJECT_TYPE:
* @object: Object to return the type id for.
*
* Get the type id of an object.
*
* Returns: Type id of @object.
*/
#define G_OBJECT_TYPE(object) (G_TYPE_FROM_INSTANCE (object))
/**
* G_OBJECT_TYPE_NAME:
* @object: Object to return the type name for.
*
* Get the name of an object's type.
*
* Returns: Type name of @object. The string is owned by the type system and
* should not be freed.
*/
#define G_OBJECT_TYPE_NAME(object) (g_type_name (G_OBJECT_TYPE (object)))
/**
* G_OBJECT_CLASS_TYPE:
* @class: a valid #GObjectClass
*
* Get the type id of a class structure.
*
* Returns: Type id of @class.
*/
#define G_OBJECT_CLASS_TYPE(class) (G_TYPE_FROM_CLASS (class))
/**
* G_OBJECT_CLASS_NAME:
* @class: a valid #GObjectClass
*
* Return the name of a class structure's type.
*
* Returns: Type name of @class. The string is owned by the type system and
* should not be freed.
*/
#define G_OBJECT_CLASS_NAME(class) (g_type_name (G_OBJECT_CLASS_TYPE (class)))
/**
* G_VALUE_HOLDS_OBJECT:
* @value: a valid #GValue structure
*
* Checks whether the given #GValue can hold values derived from type %G_TYPE_OBJECT.
*
* Returns: %TRUE on success.
*/
#define G_VALUE_HOLDS_OBJECT(value) (G_TYPE_CHECK_VALUE_TYPE ((value), G_TYPE_OBJECT))
/* --- type macros --- */
/**
* G_TYPE_INITIALLY_UNOWNED:
*
* The type for #GInitiallyUnowned.
*/
#define G_TYPE_INITIALLY_UNOWNED (g_initially_unowned_get_type())
/**
* G_INITIALLY_UNOWNED:
* @object: Object which is subject to casting.
*
* Casts a #GInitiallyUnowned or derived pointer into a (GInitiallyUnowned*)
* pointer. Depending on the current debugging level, this function may invoke
* certain runtime checks to identify invalid casts.
*/
#define G_INITIALLY_UNOWNED(object) (G_TYPE_CHECK_INSTANCE_CAST ((object), G_TYPE_INITIALLY_UNOWNED, GInitiallyUnowned))
/**
* G_INITIALLY_UNOWNED_CLASS:
* @class: a valid #GInitiallyUnownedClass
*
* Casts a derived #GInitiallyUnownedClass structure into a
* #GInitiallyUnownedClass structure.
*/
#define G_INITIALLY_UNOWNED_CLASS(class) (G_TYPE_CHECK_CLASS_CAST ((class), G_TYPE_INITIALLY_UNOWNED, GInitiallyUnownedClass))
/**
* G_IS_INITIALLY_UNOWNED:
* @object: Instance to check for being a %G_TYPE_INITIALLY_UNOWNED.
*
* Checks whether a valid #GTypeInstance pointer is of type %G_TYPE_INITIALLY_UNOWNED.
*/
#define G_IS_INITIALLY_UNOWNED(object) (G_TYPE_CHECK_INSTANCE_TYPE ((object), G_TYPE_INITIALLY_UNOWNED))
/**
* G_IS_INITIALLY_UNOWNED_CLASS:
* @class: a #GInitiallyUnownedClass
*
* Checks whether @class "is a" valid #GInitiallyUnownedClass structure of type
* %G_TYPE_INITIALLY_UNOWNED or derived.
*/
#define G_IS_INITIALLY_UNOWNED_CLASS(class) (G_TYPE_CHECK_CLASS_TYPE ((class), G_TYPE_INITIALLY_UNOWNED))
/**
* G_INITIALLY_UNOWNED_GET_CLASS:
* @object: a #GInitiallyUnowned instance.
*
* Get the class structure associated to a #GInitiallyUnowned instance.
*
* Returns: pointer to object class structure.
*/
#define G_INITIALLY_UNOWNED_GET_CLASS(object) (G_TYPE_INSTANCE_GET_CLASS ((object), G_TYPE_INITIALLY_UNOWNED, GInitiallyUnownedClass))
/* GInitiallyUnowned ia a GObject with initially floating reference count */
/* --- typedefs & structures --- */
typedef struct _GObject GObject;
typedef struct _GObjectClass GObjectClass;
typedef struct _GObject GInitiallyUnowned;
typedef struct _GObjectClass GInitiallyUnownedClass;
typedef struct _GObjectConstructParam GObjectConstructParam;
/**
* GObjectGetPropertyFunc:
* @object: a #GObject
* @property_id: the numeric id under which the property was registered with
* g_object_class_install_property().
* @value: a #GValue to return the property value in
* @pspec: the #GParamSpec describing the property
*
* The type of the @get_property function of #GObjectClass.
*/
typedef void (*GObjectGetPropertyFunc) (GObject *object,
guint property_id,
GValue *value,
GParamSpec *pspec);
/**
* GObjectSetPropertyFunc:
* @object: a #GObject
* @property_id: the numeric id under which the property was registered with
* g_object_class_install_property().
* @value: the new value for the property
* @pspec: the #GParamSpec describing the property
*
* The type of the @set_property function of #GObjectClass.
*/
typedef void (*GObjectSetPropertyFunc) (GObject *object,
guint property_id,
const GValue *value,
GParamSpec *pspec);
/**
* GObjectFinalizeFunc:
* @object: the #GObject being finalized
*
* The type of the @finalize function of #GObjectClass.
*/
typedef void (*GObjectFinalizeFunc) (GObject *object);
/**
* GWeakNotify:
* @data: data that was provided when the weak reference was established
* @where_the_object_was: the object being finalized
*
* A #GWeakNotify function can be added to an object as a callback that gets
* triggered when the object is finalized. Since the object is already being
* finalized when the #GWeakNotify is called, there's not much you could do
* with the object, apart from e.g. using its address as hash-index or the like.
*/
typedef void (*GWeakNotify) (gpointer data,
GObject *where_the_object_was);
/**
* GObject:
*
* All the fields in the GObject structure are private
* to the #GObject implementation and should never be accessed directly.
*/
struct _GObject
{
GTypeInstance g_type_instance;
/*< private >*/
volatile guint ref_count;
GData *qdata;
};
/**
* GObjectClass:
* @g_type_class: the parent class
* @constructor: the @constructor function is called by g_object_new () to
* complete the object initialization after all the construction properties are
* set. The first thing a @constructor implementation must do is chain up to the
* @constructor of the parent class. Overriding @constructor should be rarely
* needed, e.g. to handle construct properties, or to implement singletons.
* @set_property: the generic setter for all properties of this type. Should be
* overridden for every type with properties. If implementations of
* @set_property don't emit property change notification explicitly, this will
* be done implicitly by the type system. However, if the notify signal is
* emitted explicitly, the type system will not emit it a second time.
* @get_property: the generic getter for all properties of this type. Should be
* overridden for every type with properties.
* @dispose: the @dispose function is supposed to drop all references to other
* objects, but keep the instance otherwise intact, so that client method
* invocations still work. It may be run multiple times (due to reference
* loops). Before returning, @dispose should chain up to the @dispose method
* of the parent class.
* @finalize: instance finalization function, should finish the finalization of
* the instance begun in @dispose and chain up to the @finalize method of the
* parent class.
* @dispatch_properties_changed: emits property change notification for a bunch
* of properties. Overriding @dispatch_properties_changed should be rarely
* needed.
* @notify: the class closure for the notify signal
* @constructed: the @constructed function is called by g_object_new() as the
* final step of the object creation process. At the point of the call, all
* construction properties have been set on the object. The purpose of this
* call is to allow for object initialisation steps that can only be performed
* after construction properties have been set. @constructed implementors
* should chain up to the @constructed call of their parent class to allow it
* to complete its initialisation.
*
* The class structure for the GObject type.
*
* |[<!-- language="C" -->
* // Example of implementing a singleton using a constructor.
* static MySingleton *the_singleton = NULL;
*
* static GObject*
* my_singleton_constructor (GType type,
* guint n_construct_params,
* GObjectConstructParam *construct_params)
* {
* GObject *object;
*
* if (!the_singleton)
* {
* object = G_OBJECT_CLASS (parent_class)->constructor (type,
* n_construct_params,
* construct_params);
* the_singleton = MY_SINGLETON (object);
* }
* else
* object = g_object_ref (G_OBJECT (the_singleton));
*
* return object;
* }
* ]|
*/
struct _GObjectClass
{
GTypeClass g_type_class;
/*< private >*/
GSList *construct_properties;
/*< public >*/
/* seldom overidden */
GObject* (*constructor) (GType type,
guint n_construct_properties,
GObjectConstructParam *construct_properties);
/* overridable methods */
void (*set_property) (GObject *object,
guint property_id,
const GValue *value,
GParamSpec *pspec);
void (*get_property) (GObject *object,
guint property_id,
GValue *value,
GParamSpec *pspec);
void (*dispose) (GObject *object);
void (*finalize) (GObject *object);
/* seldom overidden */
void (*dispatch_properties_changed) (GObject *object,
guint n_pspecs,
GParamSpec **pspecs);
/* signals */
void (*notify) (GObject *object,
GParamSpec *pspec);
/* called when done constructing */
void (*constructed) (GObject *object);
/*< private >*/
gsize flags;
/* padding */
gpointer pdummy[6];
};
/**
* GObjectConstructParam:
* @pspec: the #GParamSpec of the construct parameter
* @value: the value to set the parameter to
*
* The GObjectConstructParam struct is an auxiliary
* structure used to hand #GParamSpec/#GValue pairs to the @constructor of
* a #GObjectClass.
*/
struct _GObjectConstructParam
{
GParamSpec *pspec;
GValue *value;
};
/**
* GInitiallyUnowned:
*
* All the fields in the GInitiallyUnowned structure
* are private to the #GInitiallyUnowned implementation and should never be
* accessed directly.
*/
/**
* GInitiallyUnownedClass:
*
* The class structure for the GInitiallyUnowned type.
*/
/* --- prototypes --- */
GLIB_AVAILABLE_IN_ALL
GType g_initially_unowned_get_type (void);
GLIB_AVAILABLE_IN_ALL
void g_object_class_install_property (GObjectClass *oclass,
guint property_id,
GParamSpec *pspec);
GLIB_AVAILABLE_IN_ALL
GParamSpec* g_object_class_find_property (GObjectClass *oclass,
const gchar *property_name);
GLIB_AVAILABLE_IN_ALL
GParamSpec**g_object_class_list_properties (GObjectClass *oclass,
guint *n_properties);
GLIB_AVAILABLE_IN_ALL
void g_object_class_override_property (GObjectClass *oclass,
guint property_id,
const gchar *name);
GLIB_AVAILABLE_IN_ALL
void g_object_class_install_properties (GObjectClass *oclass,
guint n_pspecs,
GParamSpec **pspecs);
GLIB_AVAILABLE_IN_ALL
void g_object_interface_install_property (gpointer g_iface,
GParamSpec *pspec);
GLIB_AVAILABLE_IN_ALL
GParamSpec* g_object_interface_find_property (gpointer g_iface,
const gchar *property_name);
GLIB_AVAILABLE_IN_ALL
GParamSpec**g_object_interface_list_properties (gpointer g_iface,
guint *n_properties_p);
GLIB_AVAILABLE_IN_ALL
GType g_object_get_type (void) G_GNUC_CONST;
GLIB_AVAILABLE_IN_ALL
gpointer g_object_new (GType object_type,
const gchar *first_property_name,
...);
GLIB_AVAILABLE_IN_2_54
GObject* g_object_new_with_properties (GType object_type,
guint n_properties,
const char *names[],
const GValue values[]);
GLIB_DEPRECATED_IN_2_54_FOR(g_object_new_with_properties)
gpointer g_object_newv (GType object_type,
guint n_parameters,
GParameter *parameters);
GLIB_AVAILABLE_IN_ALL
GObject* g_object_new_valist (GType object_type,
const gchar *first_property_name,
va_list var_args);
GLIB_AVAILABLE_IN_ALL
void g_object_set (gpointer object,
const gchar *first_property_name,
...) G_GNUC_NULL_TERMINATED;
GLIB_AVAILABLE_IN_ALL
void g_object_get (gpointer object,
const gchar *first_property_name,
...) G_GNUC_NULL_TERMINATED;
GLIB_AVAILABLE_IN_ALL
gpointer g_object_connect (gpointer object,
const gchar *signal_spec,
...) G_GNUC_NULL_TERMINATED;
GLIB_AVAILABLE_IN_ALL
void g_object_disconnect (gpointer object,
const gchar *signal_spec,
...) G_GNUC_NULL_TERMINATED;
GLIB_AVAILABLE_IN_2_54
void g_object_setv (GObject *object,
guint n_properties,
const gchar *names[],
const GValue values[]);
GLIB_AVAILABLE_IN_ALL
void g_object_set_valist (GObject *object,
const gchar *first_property_name,
va_list var_args);
GLIB_AVAILABLE_IN_2_54
void g_object_getv (GObject *object,
guint n_properties,
const gchar *names[],
GValue values[]);
GLIB_AVAILABLE_IN_ALL
void g_object_get_valist (GObject *object,
const gchar *first_property_name,
va_list var_args);
GLIB_AVAILABLE_IN_ALL
void g_object_set_property (GObject *object,
const gchar *property_name,
const GValue *value);
GLIB_AVAILABLE_IN_ALL
void g_object_get_property (GObject *object,
const gchar *property_name,
GValue *value);
GLIB_AVAILABLE_IN_ALL
void g_object_freeze_notify (GObject *object);
GLIB_AVAILABLE_IN_ALL
void g_object_notify (GObject *object,
const gchar *property_name);
GLIB_AVAILABLE_IN_ALL
void g_object_notify_by_pspec (GObject *object,
GParamSpec *pspec);
GLIB_AVAILABLE_IN_ALL
void g_object_thaw_notify (GObject *object);
GLIB_AVAILABLE_IN_ALL
gboolean g_object_is_floating (gpointer object);
GLIB_AVAILABLE_IN_ALL
gpointer g_object_ref_sink (gpointer object);
GLIB_AVAILABLE_IN_ALL
gpointer g_object_ref (gpointer object);
GLIB_AVAILABLE_IN_ALL
void g_object_unref (gpointer object);
GLIB_AVAILABLE_IN_ALL
void g_object_weak_ref (GObject *object,
GWeakNotify notify,
gpointer data);
GLIB_AVAILABLE_IN_ALL
void g_object_weak_unref (GObject *object,
GWeakNotify notify,
gpointer data);
GLIB_AVAILABLE_IN_ALL
void g_object_add_weak_pointer (GObject *object,
gpointer *weak_pointer_location);
GLIB_AVAILABLE_IN_ALL
void g_object_remove_weak_pointer (GObject *object,
gpointer *weak_pointer_location);
#if defined(__GNUC__) && !defined(__cplusplus) && GLIB_VERSION_MAX_ALLOWED >= GLIB_VERSION_2_56
/* Make reference APIs type safe with macros */
#define g_object_ref(Obj) ((__typeof__(Obj)) (g_object_ref) (Obj))
#define g_object_ref_sink(Obj) ((__typeof__(Obj)) (g_object_ref_sink) (Obj))
#endif
/**
* GToggleNotify:
* @data: Callback data passed to g_object_add_toggle_ref()
* @object: The object on which g_object_add_toggle_ref() was called.
* @is_last_ref: %TRUE if the toggle reference is now the
* last reference to the object. %FALSE if the toggle
* reference was the last reference and there are now other
* references.
*
* A callback function used for notification when the state
* of a toggle reference changes. See g_object_add_toggle_ref().
*/
typedef void (*GToggleNotify) (gpointer data,
GObject *object,
gboolean is_last_ref);
GLIB_AVAILABLE_IN_ALL
void g_object_add_toggle_ref (GObject *object,
GToggleNotify notify,
gpointer data);
GLIB_AVAILABLE_IN_ALL
void g_object_remove_toggle_ref (GObject *object,
GToggleNotify notify,
gpointer data);
GLIB_AVAILABLE_IN_ALL
gpointer g_object_get_qdata (GObject *object,
GQuark quark);
GLIB_AVAILABLE_IN_ALL
void g_object_set_qdata (GObject *object,
GQuark quark,
gpointer data);
GLIB_AVAILABLE_IN_ALL
void g_object_set_qdata_full (GObject *object,
GQuark quark,
gpointer data,
GDestroyNotify destroy);
GLIB_AVAILABLE_IN_ALL
gpointer g_object_steal_qdata (GObject *object,
GQuark quark);
GLIB_AVAILABLE_IN_2_34
gpointer g_object_dup_qdata (GObject *object,
GQuark quark,
GDuplicateFunc dup_func,
gpointer user_data);
GLIB_AVAILABLE_IN_2_34
gboolean g_object_replace_qdata (GObject *object,
GQuark quark,
gpointer oldval,
gpointer newval,
GDestroyNotify destroy,
GDestroyNotify *old_destroy);
GLIB_AVAILABLE_IN_ALL
gpointer g_object_get_data (GObject *object,
const gchar *key);
GLIB_AVAILABLE_IN_ALL
void g_object_set_data (GObject *object,
const gchar *key,
gpointer data);
GLIB_AVAILABLE_IN_ALL
void g_object_set_data_full (GObject *object,
const gchar *key,
gpointer data,
GDestroyNotify destroy);
GLIB_AVAILABLE_IN_ALL
gpointer g_object_steal_data (GObject *object,
const gchar *key);
GLIB_AVAILABLE_IN_2_34
gpointer g_object_dup_data (GObject *object,
const gchar *key,
GDuplicateFunc dup_func,
gpointer user_data);
GLIB_AVAILABLE_IN_2_34
gboolean g_object_replace_data (GObject *object,
const gchar *key,
gpointer oldval,
gpointer newval,
GDestroyNotify destroy,
GDestroyNotify *old_destroy);
GLIB_AVAILABLE_IN_ALL
void g_object_watch_closure (GObject *object,
GClosure *closure);
GLIB_AVAILABLE_IN_ALL
GClosure* g_cclosure_new_object (GCallback callback_func,
GObject *object);
GLIB_AVAILABLE_IN_ALL
GClosure* g_cclosure_new_object_swap (GCallback callback_func,
GObject *object);
GLIB_AVAILABLE_IN_ALL
GClosure* g_closure_new_object (guint sizeof_closure,
GObject *object);
GLIB_AVAILABLE_IN_ALL
void g_value_set_object (GValue *value,
gpointer v_object);
GLIB_AVAILABLE_IN_ALL
gpointer g_value_get_object (const GValue *value);
GLIB_AVAILABLE_IN_ALL
gpointer g_value_dup_object (const GValue *value);
GLIB_AVAILABLE_IN_ALL
gulong g_signal_connect_object (gpointer instance,
const gchar *detailed_signal,
GCallback c_handler,
gpointer gobject,
GConnectFlags connect_flags);
/*< protected >*/
GLIB_AVAILABLE_IN_ALL
void g_object_force_floating (GObject *object);
GLIB_AVAILABLE_IN_ALL
void g_object_run_dispose (GObject *object);
GLIB_AVAILABLE_IN_ALL
void g_value_take_object (GValue *value,
gpointer v_object);
GLIB_DEPRECATED_FOR(g_value_take_object)
void g_value_set_object_take_ownership (GValue *value,
gpointer v_object);
GLIB_DEPRECATED
gsize g_object_compat_control (gsize what,
gpointer data);
/* --- implementation macros --- */
#define G_OBJECT_WARN_INVALID_PSPEC(object, pname, property_id, pspec) \
G_STMT_START { \
GObject *_glib__object = (GObject*) (object); \
GParamSpec *_glib__pspec = (GParamSpec*) (pspec); \
guint _glib__property_id = (property_id); \
g_warning ("%s:%d: invalid %s id %u for \"%s\" of type '%s' in '%s'", \
__FILE__, __LINE__, \
(pname), \
_glib__property_id, \
_glib__pspec->name, \
g_type_name (G_PARAM_SPEC_TYPE (_glib__pspec)), \
G_OBJECT_TYPE_NAME (_glib__object)); \
} G_STMT_END
/**
* G_OBJECT_WARN_INVALID_PROPERTY_ID:
* @object: the #GObject on which set_property() or get_property() was called
* @property_id: the numeric id of the property
* @pspec: the #GParamSpec of the property
*
* This macro should be used to emit a standard warning about unexpected
* properties in set_property() and get_property() implementations.
*/
#define G_OBJECT_WARN_INVALID_PROPERTY_ID(object, property_id, pspec) \
G_OBJECT_WARN_INVALID_PSPEC ((object), "property", (property_id), (pspec))
GLIB_AVAILABLE_IN_ALL
void g_clear_object (volatile GObject **object_ptr);
#define g_clear_object(object_ptr) g_clear_pointer ((object_ptr), g_object_unref)
/**
* g_set_object: (skip)
* @object_ptr: a pointer to a #GObject reference
* @new_object: (nullable) (transfer none): a pointer to the new #GObject to
* assign to it, or %NULL to clear the pointer
*
* Updates a #GObject pointer to refer to @new_object. It increments the
* reference count of @new_object (if non-%NULL), decrements the reference
* count of the current value of @object_ptr (if non-%NULL), and assigns
* @new_object to @object_ptr. The assignment is not atomic.
*
* @object_ptr must not be %NULL.
*
* A macro is also included that allows this function to be used without
* pointer casts. The function itself is static inline, so its address may vary
* between compilation units.
*
* One convenient usage of this function is in implementing property setters:
* |[
* void
* foo_set_bar (Foo *foo,
* Bar *new_bar)
* {
* g_return_if_fail (IS_FOO (foo));
* g_return_if_fail (new_bar == NULL || IS_BAR (new_bar));
*
* if (g_set_object (&foo->bar, new_bar))
* g_object_notify (foo, "bar");
* }
* ]|
*
* Returns: %TRUE if the value of @object_ptr changed, %FALSE otherwise
*
* Since: 2.44
*/
static inline gboolean
(g_set_object) (GObject **object_ptr,
GObject *new_object)
{
GObject *old_object = *object_ptr;
/* rely on g_object_[un]ref() to check the pointers are actually GObjects;
* elide a (object_ptr != NULL) check because most of the time we will be
* operating on struct members with a constant offset, so a NULL check would
* not catch bugs
*/
if (old_object == new_object)
return FALSE;
if (new_object != NULL)
g_object_ref (new_object);
*object_ptr = new_object;
if (old_object != NULL)
g_object_unref (old_object);
return TRUE;
}
#define g_set_object(object_ptr, new_object) \
(/* Check types match. */ \
0 ? *(object_ptr) = (new_object), FALSE : \
(g_set_object) ((GObject **) (object_ptr), (GObject *) (new_object)) \
)
/**
* g_clear_weak_pointer: (skip)
* @weak_pointer_location: The memory address of a pointer
*
* Clears a weak reference to a #GObject.
*
* @weak_pointer_location must not be %NULL.
*
* If the weak reference is %NULL then this function does nothing.
* Otherwise, the weak reference to the object is removed for that location
* and the pointer is set to %NULL.
*
* A macro is also included that allows this function to be used without
* pointer casts. The function itself is static inline, so its address may vary
* between compilation units.
*
* Since: 2.56
*/
static inline void
(g_clear_weak_pointer) (gpointer *weak_pointer_location)
{
GObject *object = (GObject *) *weak_pointer_location;
if (object != NULL)
{
g_object_remove_weak_pointer (object, weak_pointer_location);
*weak_pointer_location = NULL;
}
}
#define g_clear_weak_pointer(weak_pointer_location) \
(/* Check types match. */ \
(g_clear_weak_pointer) ((gpointer *) (weak_pointer_location)) \
)
/**
* g_set_weak_pointer: (skip)
* @weak_pointer_location: the memory address of a pointer
* @new_object: (nullable) (transfer none): a pointer to the new #GObject to
* assign to it, or %NULL to clear the pointer
*
* Updates a pointer to weakly refer to @new_object. It assigns @new_object
* to @weak_pointer_location and ensures that @weak_pointer_location will
* automaticaly be set to %NULL if @new_object gets destroyed. The assignment
* is not atomic. The weak reference is not thread-safe, see
* g_object_add_weak_pointer() for details.
*
* @weak_pointer_location must not be %NULL.
*
* A macro is also included that allows this function to be used without
* pointer casts. The function itself is static inline, so its address may vary
* between compilation units.
*
* One convenient usage of this function is in implementing property setters:
* |[
* void
* foo_set_bar (Foo *foo,
* Bar *new_bar)
* {
* g_return_if_fail (IS_FOO (foo));
* g_return_if_fail (new_bar == NULL || IS_BAR (new_bar));
*
* if (g_set_weak_pointer (&foo->bar, new_bar))
* g_object_notify (foo, "bar");
* }
* ]|
*
* Returns: %TRUE if the value of @weak_pointer_location changed, %FALSE otherwise
*
* Since: 2.56
*/
static inline gboolean
(g_set_weak_pointer) (gpointer *weak_pointer_location,
GObject *new_object)
{
GObject *old_object = (GObject *) *weak_pointer_location;
/* elide a (weak_pointer_location != NULL) check because most of the time we
* will be operating on struct members with a constant offset, so a NULL
* check would not catch bugs
*/
if (old_object == new_object)
return FALSE;
if (old_object != NULL)
g_object_remove_weak_pointer (old_object, weak_pointer_location);
*weak_pointer_location = new_object;
if (new_object != NULL)
g_object_add_weak_pointer (new_object, weak_pointer_location);
return TRUE;
}
#define g_set_weak_pointer(weak_pointer_location, new_object) \
(/* Check types match. */ \
0 ? *(weak_pointer_location) = (new_object), FALSE : \
(g_set_weak_pointer) ((gpointer *) (weak_pointer_location), (GObject *) (new_object)) \
)
typedef struct {
/*<private>*/
union { gpointer p; } priv;
} GWeakRef;
GLIB_AVAILABLE_IN_ALL
void g_weak_ref_init (GWeakRef *weak_ref,
gpointer object);
GLIB_AVAILABLE_IN_ALL
void g_weak_ref_clear (GWeakRef *weak_ref);
GLIB_AVAILABLE_IN_ALL
gpointer g_weak_ref_get (GWeakRef *weak_ref);
GLIB_AVAILABLE_IN_ALL
void g_weak_ref_set (GWeakRef *weak_ref,
gpointer object);
G_END_DECLS
#endif /* __G_OBJECT_H__ */