1 /* GObject - GLib Type, Object, Parameter and Signal Library
2 * Copyright (C) 1998-1999, 2000-2001 Tim Janik and Red Hat, Inc.
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.
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.
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.
21 * MT safe with regards to reference counting.
30 #include "gtype-private.h"
31 #include "gvaluecollector.h"
33 #include "gparamspecs.h"
34 #include "gvaluetypes.h"
35 #include "gobject_trace.h"
36 #include "gconstructor.h"
41 * @short_description: The base object type
42 * @see_also: #GParamSpecObject, g_param_spec_object()
44 * GObject is the fundamental type providing the common attributes and
45 * methods for all object types in GTK+, Pango and other libraries
46 * based on GObject. The GObject class provides methods for object
47 * construction and destruction, property access methods, and signal
48 * support. Signals are described in detail in <xref
49 * linkend="gobject-Signals"/>.
51 * <para id="floating-ref">
52 * GInitiallyUnowned is derived from GObject. The only difference between
53 * the two is that the initial reference of a GInitiallyUnowned is flagged
54 * as a <firstterm>floating</firstterm> reference.
55 * This means that it is not specifically claimed to be "owned" by
56 * any code portion. The main motivation for providing floating references is
57 * C convenience. In particular, it allows code to be written as:
59 * container = create_container ();
60 * container_add_child (container, create_child());
62 * If <function>container_add_child()</function> will g_object_ref_sink() the
63 * passed in child, no reference of the newly created child is leaked.
64 * Without floating references, <function>container_add_child()</function>
65 * can only g_object_ref() the new child, so to implement this code without
66 * reference leaks, it would have to be written as:
69 * container = create_container ();
70 * child = create_child ();
71 * container_add_child (container, child);
72 * g_object_unref (child);
74 * The floating reference can be converted into
75 * an ordinary reference by calling g_object_ref_sink().
76 * For already sunken objects (objects that don't have a floating reference
77 * anymore), g_object_ref_sink() is equivalent to g_object_ref() and returns
79 * Since floating references are useful almost exclusively for C convenience,
80 * language bindings that provide automated reference and memory ownership
81 * maintenance (such as smart pointers or garbage collection) should not
82 * expose floating references in their API.
85 * Some object implementations may need to save an objects floating state
86 * across certain code portions (an example is #GtkMenu), to achieve this,
87 * the following sequence can be used:
90 * /* save floating state */
91 * gboolean was_floating = g_object_is_floating (object);
92 * g_object_ref_sink (object);
93 * /* protected code portion */
95 * /* restore floating state */
97 * g_object_force_floating (object);
99 * g_object_unref (object); /* release previously acquired reference */
105 #define PARAM_SPEC_PARAM_ID(pspec) ((pspec)->param_id)
106 #define PARAM_SPEC_SET_PARAM_ID(pspec, id) ((pspec)->param_id = (id))
108 #define OBJECT_HAS_TOGGLE_REF_FLAG 0x1
109 #define OBJECT_HAS_TOGGLE_REF(object) \
110 ((g_datalist_get_flags (&(object)->qdata) & OBJECT_HAS_TOGGLE_REF_FLAG) != 0)
111 #define OBJECT_FLOATING_FLAG 0x2
113 #define CLASS_HAS_PROPS_FLAG 0x1
114 #define CLASS_HAS_PROPS(class) \
115 ((class)->flags & CLASS_HAS_PROPS_FLAG)
116 #define CLASS_HAS_CUSTOM_CONSTRUCTOR(class) \
117 ((class)->constructor != g_object_constructor)
118 #define CLASS_HAS_CUSTOM_CONSTRUCTED(class) \
119 ((class)->constructed != g_object_constructed)
121 #define CLASS_HAS_DERIVED_CLASS_FLAG 0x2
122 #define CLASS_HAS_DERIVED_CLASS(class) \
123 ((class)->flags & CLASS_HAS_DERIVED_CLASS_FLAG)
125 /* --- signals --- */
132 /* --- properties --- */
138 /* --- prototypes --- */
139 static void g_object_base_class_init (GObjectClass *class);
140 static void g_object_base_class_finalize (GObjectClass *class);
141 static void g_object_do_class_init (GObjectClass *class);
142 static void g_object_init (GObject *object,
143 GObjectClass *class);
144 static GObject* g_object_constructor (GType type,
145 guint n_construct_properties,
146 GObjectConstructParam *construct_params);
147 static void g_object_constructed (GObject *object);
148 static void g_object_real_dispose (GObject *object);
149 static void g_object_finalize (GObject *object);
150 static void g_object_do_set_property (GObject *object,
154 static void g_object_do_get_property (GObject *object,
158 static void g_value_object_init (GValue *value);
159 static void g_value_object_free_value (GValue *value);
160 static void g_value_object_copy_value (const GValue *src_value,
162 static void g_value_object_transform_value (const GValue *src_value,
164 static gpointer g_value_object_peek_pointer (const GValue *value);
165 static gchar* g_value_object_collect_value (GValue *value,
166 guint n_collect_values,
167 GTypeCValue *collect_values,
168 guint collect_flags);
169 static gchar* g_value_object_lcopy_value (const GValue *value,
170 guint n_collect_values,
171 GTypeCValue *collect_values,
172 guint collect_flags);
173 static void g_object_dispatch_properties_changed (GObject *object,
175 GParamSpec **pspecs);
176 static guint object_floating_flag_handler (GObject *object,
179 static void object_interface_check_properties (gpointer func_data,
182 /* --- typedefs --- */
183 typedef struct _GObjectNotifyQueue GObjectNotifyQueue;
185 struct _GObjectNotifyQueue
189 guint16 freeze_count;
192 /* --- variables --- */
193 G_LOCK_DEFINE_STATIC (closure_array_mutex);
194 G_LOCK_DEFINE_STATIC (weak_refs_mutex);
195 G_LOCK_DEFINE_STATIC (toggle_refs_mutex);
196 static GQuark quark_closure_array = 0;
197 static GQuark quark_weak_refs = 0;
198 static GQuark quark_toggle_refs = 0;
199 static GQuark quark_notify_queue;
200 static GParamSpecPool *pspec_pool = NULL;
201 static gulong gobject_signals[LAST_SIGNAL] = { 0, };
202 static guint (*floating_flag_handler) (GObject*, gint) = object_floating_flag_handler;
203 G_LOCK_DEFINE_STATIC (construction_mutex);
204 static GSList *construction_objects = NULL;
205 /* qdata pointing to GSList<GWeakRef *>, protected by weak_locations_lock */
206 static GQuark quark_weak_locations = 0;
207 static GRWLock weak_locations_lock;
209 G_LOCK_DEFINE_STATIC(notify_lock);
211 /* --- functions --- */
213 g_object_notify_queue_free (gpointer data)
215 GObjectNotifyQueue *nqueue = data;
217 g_slist_free (nqueue->pspecs);
218 g_slice_free (GObjectNotifyQueue, nqueue);
221 static GObjectNotifyQueue*
222 g_object_notify_queue_freeze (GObject *object,
223 gboolean conditional)
225 GObjectNotifyQueue *nqueue;
228 nqueue = g_datalist_id_get_data (&object->qdata, quark_notify_queue);
233 G_UNLOCK(notify_lock);
237 nqueue = g_slice_new0 (GObjectNotifyQueue);
238 g_datalist_id_set_data_full (&object->qdata, quark_notify_queue,
239 nqueue, g_object_notify_queue_free);
242 if (nqueue->freeze_count >= 65535)
243 g_critical("Free queue for %s (%p) is larger than 65535,"
244 " called g_object_freeze_notify() too often."
245 " Forgot to call g_object_thaw_notify() or infinite loop",
246 G_OBJECT_TYPE_NAME (object), object);
248 nqueue->freeze_count++;
249 G_UNLOCK(notify_lock);
255 g_object_notify_queue_thaw (GObject *object,
256 GObjectNotifyQueue *nqueue)
258 GParamSpec *pspecs_mem[16], **pspecs, **free_me = NULL;
262 g_return_if_fail (nqueue->freeze_count > 0);
263 g_return_if_fail (g_atomic_int_get(&object->ref_count) > 0);
267 /* Just make sure we never get into some nasty race condition */
268 if (G_UNLIKELY(nqueue->freeze_count == 0)) {
269 G_UNLOCK(notify_lock);
270 g_warning ("%s: property-changed notification for %s(%p) is not frozen",
271 G_STRFUNC, G_OBJECT_TYPE_NAME (object), object);
275 nqueue->freeze_count--;
276 if (nqueue->freeze_count) {
277 G_UNLOCK(notify_lock);
281 pspecs = nqueue->n_pspecs > 16 ? free_me = g_new (GParamSpec*, nqueue->n_pspecs) : pspecs_mem;
283 for (slist = nqueue->pspecs; slist; slist = slist->next)
285 pspecs[n_pspecs++] = slist->data;
287 g_datalist_id_set_data (&object->qdata, quark_notify_queue, NULL);
289 G_UNLOCK(notify_lock);
292 G_OBJECT_GET_CLASS (object)->dispatch_properties_changed (object, n_pspecs, pspecs);
297 g_object_notify_queue_add (GObject *object,
298 GObjectNotifyQueue *nqueue,
303 g_return_if_fail (nqueue->n_pspecs < 65535);
305 if (g_slist_find (nqueue->pspecs, pspec) == NULL)
307 nqueue->pspecs = g_slist_prepend (nqueue->pspecs, pspec);
311 G_UNLOCK(notify_lock);
314 #ifdef G_ENABLE_DEBUG
315 #define IF_DEBUG(debug_type) if (_g_type_debug_flags & G_TYPE_DEBUG_ ## debug_type)
316 G_LOCK_DEFINE_STATIC (debug_objects);
317 static volatile GObject *g_trap_object_ref = NULL;
318 static guint debug_objects_count = 0;
319 static GHashTable *debug_objects_ht = NULL;
322 debug_objects_foreach (gpointer key,
326 GObject *object = value;
328 g_message ("[%p] stale %s\tref_count=%u",
330 G_OBJECT_TYPE_NAME (object),
334 #ifdef G_HAS_CONSTRUCTORS
335 #ifdef G_DEFINE_DESTRUCTOR_NEEDS_PRAGMA
336 #pragma G_DEFINE_DESTRUCTOR_PRAGMA_ARGS(debug_objects_atexit)
338 G_DEFINE_DESTRUCTOR(debug_objects_atexit)
339 #endif /* G_HAS_CONSTRUCTORS */
342 debug_objects_atexit (void)
346 G_LOCK (debug_objects);
347 g_message ("stale GObjects: %u", debug_objects_count);
348 g_hash_table_foreach (debug_objects_ht, debug_objects_foreach, NULL);
349 G_UNLOCK (debug_objects);
352 #endif /* G_ENABLE_DEBUG */
355 _g_object_type_init (void)
357 static gboolean initialized = FALSE;
358 static const GTypeFundamentalInfo finfo = {
359 G_TYPE_FLAG_CLASSED | G_TYPE_FLAG_INSTANTIATABLE | G_TYPE_FLAG_DERIVABLE | G_TYPE_FLAG_DEEP_DERIVABLE,
362 sizeof (GObjectClass),
363 (GBaseInitFunc) g_object_base_class_init,
364 (GBaseFinalizeFunc) g_object_base_class_finalize,
365 (GClassInitFunc) g_object_do_class_init,
366 NULL /* class_destroy */,
367 NULL /* class_data */,
370 (GInstanceInitFunc) g_object_init,
371 NULL, /* value_table */
373 static const GTypeValueTable value_table = {
374 g_value_object_init, /* value_init */
375 g_value_object_free_value, /* value_free */
376 g_value_object_copy_value, /* value_copy */
377 g_value_object_peek_pointer, /* value_peek_pointer */
378 "p", /* collect_format */
379 g_value_object_collect_value, /* collect_value */
380 "p", /* lcopy_format */
381 g_value_object_lcopy_value, /* lcopy_value */
385 g_return_if_fail (initialized == FALSE);
390 info.value_table = &value_table;
391 type = g_type_register_fundamental (G_TYPE_OBJECT, g_intern_static_string ("GObject"), &info, &finfo, 0);
392 g_assert (type == G_TYPE_OBJECT);
393 g_value_register_transform_func (G_TYPE_OBJECT, G_TYPE_OBJECT, g_value_object_transform_value);
395 #ifdef G_ENABLE_DEBUG
398 debug_objects_ht = g_hash_table_new (g_direct_hash, NULL);
399 #ifndef G_HAS_CONSTRUCTORS
400 g_atexit (debug_objects_atexit);
401 #endif /* G_HAS_CONSTRUCTORS */
403 #endif /* G_ENABLE_DEBUG */
407 g_object_base_class_init (GObjectClass *class)
409 GObjectClass *pclass = g_type_class_peek_parent (class);
411 /* Don't inherit HAS_DERIVED_CLASS flag from parent class */
412 class->flags &= ~CLASS_HAS_DERIVED_CLASS_FLAG;
415 pclass->flags |= CLASS_HAS_DERIVED_CLASS_FLAG;
417 /* reset instance specific fields and methods that don't get inherited */
418 class->construct_properties = pclass ? g_slist_copy (pclass->construct_properties) : NULL;
419 class->get_property = NULL;
420 class->set_property = NULL;
424 g_object_base_class_finalize (GObjectClass *class)
428 _g_signals_destroy (G_OBJECT_CLASS_TYPE (class));
430 g_slist_free (class->construct_properties);
431 class->construct_properties = NULL;
432 list = g_param_spec_pool_list_owned (pspec_pool, G_OBJECT_CLASS_TYPE (class));
433 for (node = list; node; node = node->next)
435 GParamSpec *pspec = node->data;
437 g_param_spec_pool_remove (pspec_pool, pspec);
438 PARAM_SPEC_SET_PARAM_ID (pspec, 0);
439 g_param_spec_unref (pspec);
445 g_object_do_class_init (GObjectClass *class)
447 /* read the comment about typedef struct CArray; on why not to change this quark */
448 quark_closure_array = g_quark_from_static_string ("GObject-closure-array");
450 quark_weak_refs = g_quark_from_static_string ("GObject-weak-references");
451 quark_weak_locations = g_quark_from_static_string ("GObject-weak-locations");
452 quark_toggle_refs = g_quark_from_static_string ("GObject-toggle-references");
453 quark_notify_queue = g_quark_from_static_string ("GObject-notify-queue");
454 pspec_pool = g_param_spec_pool_new (TRUE);
456 class->constructor = g_object_constructor;
457 class->constructed = g_object_constructed;
458 class->set_property = g_object_do_set_property;
459 class->get_property = g_object_do_get_property;
460 class->dispose = g_object_real_dispose;
461 class->finalize = g_object_finalize;
462 class->dispatch_properties_changed = g_object_dispatch_properties_changed;
463 class->notify = NULL;
467 * @gobject: the object which received the signal.
468 * @pspec: the #GParamSpec of the property which changed.
470 * The notify signal is emitted on an object when one of its
471 * properties has been changed. Note that getting this signal
472 * doesn't guarantee that the value of the property has actually
473 * changed, it may also be emitted when the setter for the property
474 * is called to reinstate the previous value.
476 * This signal is typically used to obtain change notification for a
477 * single property, by specifying the property name as a detail in the
478 * g_signal_connect() call, like this:
480 * g_signal_connect (text_view->buffer, "notify::paste-target-list",
481 * G_CALLBACK (gtk_text_view_target_list_notify),
484 * It is important to note that you must use
485 * <link linkend="canonical-parameter-name">canonical</link> parameter names as
486 * detail strings for the notify signal.
488 gobject_signals[NOTIFY] =
489 g_signal_new (g_intern_static_string ("notify"),
490 G_TYPE_FROM_CLASS (class),
491 G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE | G_SIGNAL_DETAILED | G_SIGNAL_NO_HOOKS | G_SIGNAL_ACTION,
492 G_STRUCT_OFFSET (GObjectClass, notify),
494 g_cclosure_marshal_VOID__PARAM,
498 /* Install a check function that we'll use to verify that classes that
499 * implement an interface implement all properties for that interface
501 g_type_add_interface_check (NULL, object_interface_check_properties);
505 install_property_internal (GType g_type,
509 if (g_param_spec_pool_lookup (pspec_pool, pspec->name, g_type, FALSE))
511 g_warning ("When installing property: type `%s' already has a property named `%s'",
512 g_type_name (g_type),
517 g_param_spec_ref_sink (pspec);
518 PARAM_SPEC_SET_PARAM_ID (pspec, property_id);
519 g_param_spec_pool_insert (pspec_pool, pspec, g_type);
523 * g_object_class_install_property:
524 * @oclass: a #GObjectClass
525 * @property_id: the id for the new property
526 * @pspec: the #GParamSpec for the new property
528 * Installs a new property. This is usually done in the class initializer.
530 * Note that it is possible to redefine a property in a derived class,
531 * by installing a property with the same name. This can be useful at times,
532 * e.g. to change the range of allowed values or the default value.
535 g_object_class_install_property (GObjectClass *class,
539 g_return_if_fail (G_IS_OBJECT_CLASS (class));
540 g_return_if_fail (G_IS_PARAM_SPEC (pspec));
542 if (CLASS_HAS_DERIVED_CLASS (class))
543 g_error ("Attempt to add property %s::%s to class after it was derived",
544 G_OBJECT_CLASS_NAME (class), pspec->name);
546 class->flags |= CLASS_HAS_PROPS_FLAG;
548 g_return_if_fail (pspec->flags & (G_PARAM_READABLE | G_PARAM_WRITABLE));
549 if (pspec->flags & G_PARAM_WRITABLE)
550 g_return_if_fail (class->set_property != NULL);
551 if (pspec->flags & G_PARAM_READABLE)
552 g_return_if_fail (class->get_property != NULL);
553 g_return_if_fail (property_id > 0);
554 g_return_if_fail (PARAM_SPEC_PARAM_ID (pspec) == 0); /* paranoid */
555 if (pspec->flags & G_PARAM_CONSTRUCT)
556 g_return_if_fail ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) == 0);
557 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
558 g_return_if_fail (pspec->flags & G_PARAM_WRITABLE);
560 install_property_internal (G_OBJECT_CLASS_TYPE (class), property_id, pspec);
562 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
563 class->construct_properties = g_slist_append (class->construct_properties, pspec);
565 /* for property overrides of construct properties, we have to get rid
566 * of the overidden inherited construct property
568 pspec = g_param_spec_pool_lookup (pspec_pool, pspec->name, g_type_parent (G_OBJECT_CLASS_TYPE (class)), TRUE);
569 if (pspec && pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
570 class->construct_properties = g_slist_remove (class->construct_properties, pspec);
574 * g_object_class_install_properties:
575 * @oclass: a #GObjectClass
576 * @n_pspecs: the length of the #GParamSpec<!-- -->s array
577 * @pspecs: (array length=n_pspecs): the #GParamSpec<!-- -->s array
578 * defining the new properties
580 * Installs new properties from an array of #GParamSpec<!-- -->s. This is
581 * usually done in the class initializer.
583 * The property id of each property is the index of each #GParamSpec in
586 * The property id of 0 is treated specially by #GObject and it should not
587 * be used to store a #GParamSpec.
589 * This function should be used if you plan to use a static array of
590 * #GParamSpec<!-- -->s and g_object_notify_by_pspec(). For instance, this
591 * class initialization:
595 * PROP_0, PROP_FOO, PROP_BAR, N_PROPERTIES
598 * static GParamSpec *obj_properties[N_PROPERTIES] = { NULL, };
601 * my_object_class_init (MyObjectClass *klass)
603 * GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
605 * obj_properties[PROP_FOO] =
606 * g_param_spec_int ("foo", "Foo", "Foo",
609 * G_PARAM_READWRITE);
611 * obj_properties[PROP_BAR] =
612 * g_param_spec_string ("bar", "Bar", "Bar",
614 * G_PARAM_READWRITE);
616 * gobject_class->set_property = my_object_set_property;
617 * gobject_class->get_property = my_object_get_property;
618 * g_object_class_install_properties (gobject_class,
624 * allows calling g_object_notify_by_pspec() to notify of property changes:
628 * my_object_set_foo (MyObject *self, gint foo)
630 * if (self->foo != foo)
633 * g_object_notify_by_pspec (G_OBJECT (self), obj_properties[PROP_FOO]);
641 g_object_class_install_properties (GObjectClass *oclass,
645 GType oclass_type, parent_type;
648 g_return_if_fail (G_IS_OBJECT_CLASS (oclass));
649 g_return_if_fail (n_pspecs > 1);
650 g_return_if_fail (pspecs[0] == NULL);
652 if (CLASS_HAS_DERIVED_CLASS (oclass))
653 g_error ("Attempt to add properties to %s after it was derived",
654 G_OBJECT_CLASS_NAME (oclass));
656 oclass_type = G_OBJECT_CLASS_TYPE (oclass);
657 parent_type = g_type_parent (oclass_type);
659 /* we skip the first element of the array as it would have a 0 prop_id */
660 for (i = 1; i < n_pspecs; i++)
662 GParamSpec *pspec = pspecs[i];
664 g_return_if_fail (pspec != NULL);
666 if (pspec->flags & G_PARAM_WRITABLE)
667 g_return_if_fail (oclass->set_property != NULL);
668 if (pspec->flags & G_PARAM_READABLE)
669 g_return_if_fail (oclass->get_property != NULL);
670 g_return_if_fail (PARAM_SPEC_PARAM_ID (pspec) == 0); /* paranoid */
671 if (pspec->flags & G_PARAM_CONSTRUCT)
672 g_return_if_fail ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) == 0);
673 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
674 g_return_if_fail (pspec->flags & G_PARAM_WRITABLE);
676 oclass->flags |= CLASS_HAS_PROPS_FLAG;
677 install_property_internal (oclass_type, i, pspec);
679 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
680 oclass->construct_properties = g_slist_append (oclass->construct_properties, pspec);
682 /* for property overrides of construct properties, we have to get rid
683 * of the overidden inherited construct property
685 pspec = g_param_spec_pool_lookup (pspec_pool, pspec->name, parent_type, TRUE);
686 if (pspec && pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
687 oclass->construct_properties = g_slist_remove (oclass->construct_properties, pspec);
692 * g_object_interface_install_property:
693 * @g_iface: any interface vtable for the interface, or the default
694 * vtable for the interface.
695 * @pspec: the #GParamSpec for the new property
697 * Add a property to an interface; this is only useful for interfaces
698 * that are added to GObject-derived types. Adding a property to an
699 * interface forces all objects classes with that interface to have a
700 * compatible property. The compatible property could be a newly
701 * created #GParamSpec, but normally
702 * g_object_class_override_property() will be used so that the object
703 * class only needs to provide an implementation and inherits the
704 * property description, default value, bounds, and so forth from the
705 * interface property.
707 * This function is meant to be called from the interface's default
708 * vtable initialization function (the @class_init member of
709 * #GTypeInfo.) It must not be called after after @class_init has
710 * been called for any object types implementing this interface.
715 g_object_interface_install_property (gpointer g_iface,
718 GTypeInterface *iface_class = g_iface;
720 g_return_if_fail (G_TYPE_IS_INTERFACE (iface_class->g_type));
721 g_return_if_fail (G_IS_PARAM_SPEC (pspec));
722 g_return_if_fail (!G_IS_PARAM_SPEC_OVERRIDE (pspec)); /* paranoid */
723 g_return_if_fail (PARAM_SPEC_PARAM_ID (pspec) == 0); /* paranoid */
725 g_return_if_fail (pspec->flags & (G_PARAM_READABLE | G_PARAM_WRITABLE));
726 if (pspec->flags & G_PARAM_CONSTRUCT)
727 g_return_if_fail ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) == 0);
728 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
729 g_return_if_fail (pspec->flags & G_PARAM_WRITABLE);
731 install_property_internal (iface_class->g_type, 0, pspec);
735 * g_object_class_find_property:
736 * @oclass: a #GObjectClass
737 * @property_name: the name of the property to look up
739 * Looks up the #GParamSpec for a property of a class.
741 * Returns: (transfer none): the #GParamSpec for the property, or
742 * %NULL if the class doesn't have a property of that name
745 g_object_class_find_property (GObjectClass *class,
746 const gchar *property_name)
749 GParamSpec *redirect;
751 g_return_val_if_fail (G_IS_OBJECT_CLASS (class), NULL);
752 g_return_val_if_fail (property_name != NULL, NULL);
754 pspec = g_param_spec_pool_lookup (pspec_pool,
756 G_OBJECT_CLASS_TYPE (class),
760 redirect = g_param_spec_get_redirect_target (pspec);
771 * g_object_interface_find_property:
772 * @g_iface: any interface vtable for the interface, or the default
773 * vtable for the interface
774 * @property_name: name of a property to lookup.
776 * Find the #GParamSpec with the given name for an
777 * interface. Generally, the interface vtable passed in as @g_iface
778 * will be the default vtable from g_type_default_interface_ref(), or,
779 * if you know the interface has already been loaded,
780 * g_type_default_interface_peek().
784 * Returns: (transfer none): the #GParamSpec for the property of the
785 * interface with the name @property_name, or %NULL if no
786 * such property exists.
789 g_object_interface_find_property (gpointer g_iface,
790 const gchar *property_name)
792 GTypeInterface *iface_class = g_iface;
794 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface_class->g_type), NULL);
795 g_return_val_if_fail (property_name != NULL, NULL);
797 return g_param_spec_pool_lookup (pspec_pool,
804 * g_object_class_override_property:
805 * @oclass: a #GObjectClass
806 * @property_id: the new property ID
807 * @name: the name of a property registered in a parent class or
808 * in an interface of this class.
810 * Registers @property_id as referring to a property with the
811 * name @name in a parent class or in an interface implemented
812 * by @oclass. This allows this class to <firstterm>override</firstterm>
813 * a property implementation in a parent class or to provide
814 * the implementation of a property from an interface.
817 * Internally, overriding is implemented by creating a property of type
818 * #GParamSpecOverride; generally operations that query the properties of
819 * the object class, such as g_object_class_find_property() or
820 * g_object_class_list_properties() will return the overridden
821 * property. However, in one case, the @construct_properties argument of
822 * the @constructor virtual function, the #GParamSpecOverride is passed
823 * instead, so that the @param_id field of the #GParamSpec will be
824 * correct. For virtually all uses, this makes no difference. If you
825 * need to get the overridden property, you can call
826 * g_param_spec_get_redirect_target().
832 g_object_class_override_property (GObjectClass *oclass,
836 GParamSpec *overridden = NULL;
840 g_return_if_fail (G_IS_OBJECT_CLASS (oclass));
841 g_return_if_fail (property_id > 0);
842 g_return_if_fail (name != NULL);
844 /* Find the overridden property; first check parent types
846 parent_type = g_type_parent (G_OBJECT_CLASS_TYPE (oclass));
847 if (parent_type != G_TYPE_NONE)
848 overridden = g_param_spec_pool_lookup (pspec_pool,
857 /* Now check interfaces
859 ifaces = g_type_interfaces (G_OBJECT_CLASS_TYPE (oclass), &n_ifaces);
860 while (n_ifaces-- && !overridden)
862 overridden = g_param_spec_pool_lookup (pspec_pool,
873 g_warning ("%s: Can't find property to override for '%s::%s'",
874 G_STRFUNC, G_OBJECT_CLASS_NAME (oclass), name);
878 new = g_param_spec_override (name, overridden);
879 g_object_class_install_property (oclass, property_id, new);
883 * g_object_class_list_properties:
884 * @oclass: a #GObjectClass
885 * @n_properties: (out): return location for the length of the returned array
887 * Get an array of #GParamSpec* for all properties of a class.
889 * Returns: (array length=n_properties) (transfer container): an array of
890 * #GParamSpec* which should be freed after use
892 GParamSpec** /* free result */
893 g_object_class_list_properties (GObjectClass *class,
894 guint *n_properties_p)
899 g_return_val_if_fail (G_IS_OBJECT_CLASS (class), NULL);
901 pspecs = g_param_spec_pool_list (pspec_pool,
902 G_OBJECT_CLASS_TYPE (class),
911 * g_object_interface_list_properties:
912 * @g_iface: any interface vtable for the interface, or the default
913 * vtable for the interface
914 * @n_properties_p: (out): location to store number of properties returned.
916 * Lists the properties of an interface.Generally, the interface
917 * vtable passed in as @g_iface will be the default vtable from
918 * g_type_default_interface_ref(), or, if you know the interface has
919 * already been loaded, g_type_default_interface_peek().
923 * Returns: (array length=n_properties_p) (transfer container): a
924 * pointer to an array of pointers to #GParamSpec
925 * structures. The paramspecs are owned by GLib, but the
926 * array should be freed with g_free() when you are done with
930 g_object_interface_list_properties (gpointer g_iface,
931 guint *n_properties_p)
933 GTypeInterface *iface_class = g_iface;
937 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface_class->g_type), NULL);
939 pspecs = g_param_spec_pool_list (pspec_pool,
949 g_object_init (GObject *object,
952 object->ref_count = 1;
953 object->qdata = NULL;
955 if (CLASS_HAS_PROPS (class))
957 /* freeze object's notification queue, g_object_newv() preserves pairedness */
958 g_object_notify_queue_freeze (object, FALSE);
961 if (CLASS_HAS_CUSTOM_CONSTRUCTOR (class))
963 /* enter construction list for notify_queue_thaw() and to allow construct-only properties */
964 G_LOCK (construction_mutex);
965 construction_objects = g_slist_prepend (construction_objects, object);
966 G_UNLOCK (construction_mutex);
969 #ifdef G_ENABLE_DEBUG
972 G_LOCK (debug_objects);
973 debug_objects_count++;
974 g_hash_table_insert (debug_objects_ht, object, object);
975 G_UNLOCK (debug_objects);
977 #endif /* G_ENABLE_DEBUG */
981 g_object_do_set_property (GObject *object,
989 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
995 g_object_do_get_property (GObject *object,
1000 switch (property_id)
1003 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
1009 g_object_real_dispose (GObject *object)
1011 g_signal_handlers_destroy (object);
1012 g_datalist_id_set_data (&object->qdata, quark_closure_array, NULL);
1013 g_datalist_id_set_data (&object->qdata, quark_weak_refs, NULL);
1017 g_object_finalize (GObject *object)
1019 g_datalist_clear (&object->qdata);
1021 #ifdef G_ENABLE_DEBUG
1024 G_LOCK (debug_objects);
1025 g_assert (g_hash_table_lookup (debug_objects_ht, object) == object);
1026 g_hash_table_remove (debug_objects_ht, object);
1027 debug_objects_count--;
1028 G_UNLOCK (debug_objects);
1030 #endif /* G_ENABLE_DEBUG */
1035 g_object_dispatch_properties_changed (GObject *object,
1037 GParamSpec **pspecs)
1041 for (i = 0; i < n_pspecs; i++)
1042 g_signal_emit (object, gobject_signals[NOTIFY], g_quark_from_string (pspecs[i]->name), pspecs[i]);
1046 * g_object_run_dispose:
1047 * @object: a #GObject
1049 * Releases all references to other objects. This can be used to break
1052 * This functions should only be called from object system implementations.
1055 g_object_run_dispose (GObject *object)
1057 g_return_if_fail (G_IS_OBJECT (object));
1058 g_return_if_fail (object->ref_count > 0);
1060 g_object_ref (object);
1061 TRACE (GOBJECT_OBJECT_DISPOSE(object,G_TYPE_FROM_INSTANCE(object), 0));
1062 G_OBJECT_GET_CLASS (object)->dispose (object);
1063 TRACE (GOBJECT_OBJECT_DISPOSE_END(object,G_TYPE_FROM_INSTANCE(object), 0));
1064 g_object_unref (object);
1068 * g_object_freeze_notify:
1069 * @object: a #GObject
1071 * Increases the freeze count on @object. If the freeze count is
1072 * non-zero, the emission of "notify" signals on @object is
1073 * stopped. The signals are queued until the freeze count is decreased
1074 * to zero. Duplicate notifications are squashed so that at most one
1075 * #GObject::notify signal is emitted for each property modified while the
1078 * This is necessary for accessors that modify multiple properties to prevent
1079 * premature notification while the object is still being modified.
1082 g_object_freeze_notify (GObject *object)
1084 g_return_if_fail (G_IS_OBJECT (object));
1086 if (g_atomic_int_get (&object->ref_count) == 0)
1089 g_object_ref (object);
1090 g_object_notify_queue_freeze (object, FALSE);
1091 g_object_unref (object);
1095 get_notify_pspec (GParamSpec *pspec)
1097 GParamSpec *redirected;
1099 /* we don't notify on non-READABLE parameters */
1100 if (~pspec->flags & G_PARAM_READABLE)
1103 /* if the paramspec is redirected, notify on the target */
1104 redirected = g_param_spec_get_redirect_target (pspec);
1105 if (redirected != NULL)
1108 /* else, notify normally */
1113 g_object_notify_by_spec_internal (GObject *object,
1116 GParamSpec *notify_pspec;
1118 notify_pspec = get_notify_pspec (pspec);
1120 if (notify_pspec != NULL)
1122 GObjectNotifyQueue *nqueue;
1124 /* conditional freeze: only increase freeze count if already frozen */
1125 nqueue = g_object_notify_queue_freeze (object, TRUE);
1129 /* we're frozen, so add to the queue and release our freeze */
1130 g_object_notify_queue_add (object, nqueue, notify_pspec);
1131 g_object_notify_queue_thaw (object, nqueue);
1134 /* not frozen, so just dispatch the notification directly */
1135 G_OBJECT_GET_CLASS (object)
1136 ->dispatch_properties_changed (object, 1, ¬ify_pspec);
1142 * @object: a #GObject
1143 * @property_name: the name of a property installed on the class of @object.
1145 * Emits a "notify" signal for the property @property_name on @object.
1147 * When possible, eg. when signaling a property change from within the class
1148 * that registered the property, you should use g_object_notify_by_pspec()
1152 g_object_notify (GObject *object,
1153 const gchar *property_name)
1157 g_return_if_fail (G_IS_OBJECT (object));
1158 g_return_if_fail (property_name != NULL);
1159 if (g_atomic_int_get (&object->ref_count) == 0)
1162 g_object_ref (object);
1163 /* We don't need to get the redirect target
1164 * (by, e.g. calling g_object_class_find_property())
1165 * because g_object_notify_queue_add() does that
1167 pspec = g_param_spec_pool_lookup (pspec_pool,
1169 G_OBJECT_TYPE (object),
1173 g_warning ("%s: object class `%s' has no property named `%s'",
1175 G_OBJECT_TYPE_NAME (object),
1178 g_object_notify_by_spec_internal (object, pspec);
1179 g_object_unref (object);
1183 * g_object_notify_by_pspec:
1184 * @object: a #GObject
1185 * @pspec: the #GParamSpec of a property installed on the class of @object.
1187 * Emits a "notify" signal for the property specified by @pspec on @object.
1189 * This function omits the property name lookup, hence it is faster than
1190 * g_object_notify().
1192 * One way to avoid using g_object_notify() from within the
1193 * class that registered the properties, and using g_object_notify_by_pspec()
1194 * instead, is to store the GParamSpec used with
1195 * g_object_class_install_property() inside a static array, e.g.:
1205 * static GParamSpec *properties[PROP_LAST];
1208 * my_object_class_init (MyObjectClass *klass)
1210 * properties[PROP_FOO] = g_param_spec_int ("foo", "Foo", "The foo",
1213 * G_PARAM_READWRITE);
1214 * g_object_class_install_property (gobject_class,
1216 * properties[PROP_FOO]);
1220 * and then notify a change on the "foo" property with:
1223 * g_object_notify_by_pspec (self, properties[PROP_FOO]);
1229 g_object_notify_by_pspec (GObject *object,
1233 g_return_if_fail (G_IS_OBJECT (object));
1234 g_return_if_fail (G_IS_PARAM_SPEC (pspec));
1236 g_object_ref (object);
1237 g_object_notify_by_spec_internal (object, pspec);
1238 g_object_unref (object);
1242 * g_object_thaw_notify:
1243 * @object: a #GObject
1245 * Reverts the effect of a previous call to
1246 * g_object_freeze_notify(). The freeze count is decreased on @object
1247 * and when it reaches zero, queued "notify" signals are emitted.
1249 * Duplicate notifications for each property are squashed so that at most one
1250 * #GObject::notify signal is emitted for each property.
1252 * It is an error to call this function when the freeze count is zero.
1255 g_object_thaw_notify (GObject *object)
1257 GObjectNotifyQueue *nqueue;
1259 g_return_if_fail (G_IS_OBJECT (object));
1260 if (g_atomic_int_get (&object->ref_count) == 0)
1263 g_object_ref (object);
1265 /* FIXME: Freezing is the only way to get at the notify queue.
1266 * So we freeze once and then thaw twice.
1268 nqueue = g_object_notify_queue_freeze (object, FALSE);
1269 g_object_notify_queue_thaw (object, nqueue);
1270 g_object_notify_queue_thaw (object, nqueue);
1272 g_object_unref (object);
1276 object_get_property (GObject *object,
1280 GObjectClass *class = g_type_class_peek (pspec->owner_type);
1281 guint param_id = PARAM_SPEC_PARAM_ID (pspec);
1282 GParamSpec *redirect;
1286 g_warning ("'%s::%s' is not a valid property name; '%s' is not a GObject subtype",
1287 g_type_name (pspec->owner_type), pspec->name, g_type_name (pspec->owner_type));
1291 redirect = g_param_spec_get_redirect_target (pspec);
1295 class->get_property (object, param_id, value, pspec);
1299 object_set_property (GObject *object,
1301 const GValue *value,
1302 GObjectNotifyQueue *nqueue)
1304 GValue tmp_value = G_VALUE_INIT;
1305 GObjectClass *class = g_type_class_peek (pspec->owner_type);
1306 guint param_id = PARAM_SPEC_PARAM_ID (pspec);
1307 GParamSpec *redirect;
1308 static const gchar * enable_diagnostic = NULL;
1312 g_warning ("'%s::%s' is not a valid property name; '%s' is not a GObject subtype",
1313 g_type_name (pspec->owner_type), pspec->name, g_type_name (pspec->owner_type));
1317 redirect = g_param_spec_get_redirect_target (pspec);
1321 if (G_UNLIKELY (!enable_diagnostic))
1323 enable_diagnostic = g_getenv ("G_ENABLE_DIAGNOSTIC");
1324 if (!enable_diagnostic)
1325 enable_diagnostic = "0";
1328 if (enable_diagnostic[0] == '1')
1330 if (pspec->flags & G_PARAM_DEPRECATED)
1331 g_warning ("The property %s:%s is deprecated and shouldn't be used "
1332 "anymore. It will be removed in a future version.",
1333 G_OBJECT_TYPE_NAME (object), pspec->name);
1336 /* provide a copy to work from, convert (if necessary) and validate */
1337 g_value_init (&tmp_value, pspec->value_type);
1338 if (!g_value_transform (value, &tmp_value))
1339 g_warning ("unable to set property `%s' of type `%s' from value of type `%s'",
1341 g_type_name (pspec->value_type),
1342 G_VALUE_TYPE_NAME (value));
1343 else if (g_param_value_validate (pspec, &tmp_value) && !(pspec->flags & G_PARAM_LAX_VALIDATION))
1345 gchar *contents = g_strdup_value_contents (value);
1347 g_warning ("value \"%s\" of type `%s' is invalid or out of range for property `%s' of type `%s'",
1349 G_VALUE_TYPE_NAME (value),
1351 g_type_name (pspec->value_type));
1356 GParamSpec *notify_pspec;
1358 class->set_property (object, param_id, &tmp_value, pspec);
1360 notify_pspec = get_notify_pspec (pspec);
1362 if (notify_pspec != NULL)
1363 g_object_notify_queue_add (object, nqueue, notify_pspec);
1365 g_value_unset (&tmp_value);
1369 object_interface_check_properties (gpointer func_data,
1372 GTypeInterface *iface_class = g_iface;
1373 GObjectClass *class;
1374 GType iface_type = iface_class->g_type;
1375 GParamSpec **pspecs;
1378 class = g_type_class_ref (iface_class->g_instance_type);
1380 if (!G_IS_OBJECT_CLASS (class))
1383 pspecs = g_param_spec_pool_list (pspec_pool, iface_type, &n);
1387 GParamSpec *class_pspec = g_param_spec_pool_lookup (pspec_pool,
1389 G_OBJECT_CLASS_TYPE (class),
1394 g_critical ("Object class %s doesn't implement property "
1395 "'%s' from interface '%s'",
1396 g_type_name (G_OBJECT_CLASS_TYPE (class)),
1398 g_type_name (iface_type));
1403 /* We do a number of checks on the properties of an interface to
1404 * make sure that all classes implementing the interface are
1405 * overriding the properties in a sane way.
1407 * We do the checks in order of importance so that we can give
1408 * more useful error messages first.
1410 * First, we check that the implementation doesn't remove the
1411 * basic functionality (readability, writability) advertised by
1412 * the interface. Next, we check that it doesn't introduce
1413 * additional restrictions (such as construct-only). Finally, we
1414 * make sure the types are compatible.
1417 #define SUBSET(a,b,mask) (((a) & ~(b) & (mask)) == 0)
1418 /* If the property on the interface is readable then the
1419 * implementation must be readable. If the interface is writable
1420 * then the implementation must be writable.
1422 if (!SUBSET (pspecs[n]->flags, class_pspec->flags, G_PARAM_READABLE | G_PARAM_WRITABLE))
1424 g_critical ("Flags for property '%s' on class '%s' remove functionality compared with the "
1425 "property on interface '%s'\n", pspecs[n]->name,
1426 g_type_name (G_OBJECT_CLASS_TYPE (class)), g_type_name (iface_type));
1430 /* If the property on the interface is writable then we need to
1431 * make sure the implementation doesn't introduce new restrictions
1432 * on that writability (ie: construct-only).
1434 * If the interface was not writable to begin with then we don't
1435 * really have any problems here because "writable at construct
1436 * type only" is still more permissive than "read only".
1438 if (pspecs[n]->flags & G_PARAM_WRITABLE)
1440 if (!SUBSET (class_pspec->flags, pspecs[n]->flags, G_PARAM_CONSTRUCT_ONLY))
1442 g_critical ("Flags for property '%s' on class '%s' introduce additional restrictions on "
1443 "writability compared with the property on interface '%s'\n", pspecs[n]->name,
1444 g_type_name (G_OBJECT_CLASS_TYPE (class)), g_type_name (iface_type));
1450 /* If the property on the interface is readable then we are
1451 * effectively advertising that reading the property will return a
1452 * value of a specific type. All implementations of the interface
1453 * need to return items of this type -- but may be more
1454 * restrictive. For example, it is legal to have:
1456 * GtkWidget *get_item();
1458 * that is implemented by a function that always returns a
1459 * GtkEntry. In short: readability implies that the
1460 * implementation value type must be equal or more restrictive.
1462 * Similarly, if the property on the interface is writable then
1463 * must be able to accept the property being set to any value of
1464 * that type, including subclasses. In this case, we may also be
1465 * less restrictive. For example, it is legal to have:
1467 * set_item (GtkEntry *);
1469 * that is implemented by a function that will actually work with
1470 * any GtkWidget. In short: writability implies that the
1471 * implementation value type must be equal or less restrictive.
1473 * In the case that the property is both readable and writable
1474 * then the only way that both of the above can be satisfied is
1475 * with a type that is exactly equal.
1477 switch (pspecs[n]->flags & (G_PARAM_READABLE | G_PARAM_WRITABLE))
1479 case G_PARAM_READABLE | G_PARAM_WRITABLE:
1480 /* class pspec value type must have exact equality with interface */
1481 if (pspecs[n]->value_type != class_pspec->value_type)
1482 g_critical ("Read/writable property '%s' on class '%s' has type '%s' which is not exactly equal to the "
1483 "type '%s' of the property on the interface '%s'\n", pspecs[n]->name,
1484 g_type_name (G_OBJECT_CLASS_TYPE (class)), g_type_name (G_PARAM_SPEC_VALUE_TYPE (class_pspec)),
1485 g_type_name (G_PARAM_SPEC_VALUE_TYPE (pspecs[n])), g_type_name (iface_type));
1488 case G_PARAM_READABLE:
1489 /* class pspec value type equal or more restrictive than interface */
1490 if (!g_type_is_a (class_pspec->value_type, pspecs[n]->value_type))
1491 g_critical ("Read-only property '%s' on class '%s' has type '%s' which is not equal to or more "
1492 "restrictive than the type '%s' of the property on the interface '%s'\n", pspecs[n]->name,
1493 g_type_name (G_OBJECT_CLASS_TYPE (class)), g_type_name (G_PARAM_SPEC_VALUE_TYPE (class_pspec)),
1494 g_type_name (G_PARAM_SPEC_VALUE_TYPE (pspecs[n])), g_type_name (iface_type));
1497 case G_PARAM_WRITABLE:
1498 /* class pspec value type equal or less restrictive than interface */
1499 if (!g_type_is_a (pspecs[n]->value_type, class_pspec->value_type))
1500 g_critical ("Write-only property '%s' on class '%s' has type '%s' which is not equal to or less "
1501 "restrictive than the type '%s' of the property on the interface '%s' \n", pspecs[n]->name,
1502 g_type_name (G_OBJECT_CLASS_TYPE (class)), g_type_name (G_PARAM_SPEC_VALUE_TYPE (class_pspec)),
1503 g_type_name (G_PARAM_SPEC_VALUE_TYPE (pspecs[n])), g_type_name (iface_type));
1507 g_assert_not_reached ();
1513 g_type_class_unref (class);
1517 g_object_get_type (void)
1519 return G_TYPE_OBJECT;
1523 * g_object_new: (skip)
1524 * @object_type: the type id of the #GObject subtype to instantiate
1525 * @first_property_name: the name of the first property
1526 * @...: the value of the first property, followed optionally by more
1527 * name/value pairs, followed by %NULL
1529 * Creates a new instance of a #GObject subtype and sets its properties.
1531 * Construction parameters (see #G_PARAM_CONSTRUCT, #G_PARAM_CONSTRUCT_ONLY)
1532 * which are not explicitly specified are set to their default values.
1534 * Returns: (transfer full): a new instance of @object_type
1537 g_object_new (GType object_type,
1538 const gchar *first_property_name,
1544 g_return_val_if_fail (G_TYPE_IS_OBJECT (object_type), NULL);
1546 /* short circuit for calls supplying no properties */
1547 if (!first_property_name)
1548 return g_object_newv (object_type, 0, NULL);
1550 va_start (var_args, first_property_name);
1551 object = g_object_new_valist (object_type, first_property_name, var_args);
1558 slist_maybe_remove (GSList **slist,
1561 GSList *last = NULL, *node = *slist;
1564 if (node->data == data)
1567 last->next = node->next;
1569 *slist = node->next;
1570 g_slist_free_1 (node);
1579 static inline gboolean
1580 object_in_construction_list (GObject *object)
1582 gboolean in_construction;
1583 G_LOCK (construction_mutex);
1584 in_construction = g_slist_find (construction_objects, object) != NULL;
1585 G_UNLOCK (construction_mutex);
1586 return in_construction;
1590 g_object_new_with_custom_constructor (GObjectClass *class,
1591 GObjectConstructParam *params,
1594 GObjectNotifyQueue *nqueue = NULL;
1595 gboolean newly_constructed;
1596 GObjectConstructParam *cparams;
1604 /* If we have ->constructed() then we have to do a lot more work.
1605 * It's possible that this is a singleton and it's also possible
1606 * that the user's constructor() will attempt to modify the values
1607 * that we pass in, so we'll need to allocate copies of them.
1608 * It's also possible that the user may attempt to call
1609 * g_object_set() from inside of their constructor, so we need to
1610 * add ourselves to a list of objects for which that is allowed
1611 * while their constructor() is running.
1614 /* Create the array of GObjectConstructParams for constructor() */
1615 n_cparams = g_slist_length (class->construct_properties);
1616 cparams = g_new (GObjectConstructParam, n_cparams);
1617 cvalues = g_new0 (GValue, n_cparams);
1621 /* As above, we may find the value in the passed-in params list.
1623 * If we have the value passed in then we can use the GValue from
1624 * it directly because it is safe to modify. If we use the
1625 * default value from the class, we had better not pass that in
1626 * and risk it being modified, so we create a new one.
1628 for (node = class->construct_properties; node; node = node->next)
1635 value = NULL; /* to silence gcc... */
1637 for (j = 0; j < n_params; j++)
1638 if (params[j].pspec == pspec)
1640 value = params[j].value;
1646 value = &cvalues[cvals_used++];
1647 g_value_init (value, pspec->value_type);
1648 g_param_value_set_default (pspec, value);
1651 cparams[i].pspec = pspec;
1652 cparams[i].value = value;
1656 /* construct object from construction parameters */
1657 object = class->constructor (class->g_type_class.g_type, n_cparams, cparams);
1658 /* free construction values */
1660 while (cvals_used--)
1661 g_value_unset (&cvalues[cvals_used]);
1664 /* g_object_init() will have added us to the construction_objects
1665 * list. Check if we're in it (and remove us) in order to find
1666 * out if we were newly-constructed or this is an already-existing
1667 * singleton (in which case we should not do 'constructed').
1669 G_LOCK (construction_mutex);
1670 newly_constructed = slist_maybe_remove (&construction_objects, object);
1671 G_UNLOCK (construction_mutex);
1673 if (CLASS_HAS_PROPS (class))
1675 /* If this object was newly_constructed then g_object_init()
1676 * froze the queue. We need to freeze it here in order to get
1677 * the handle so that we can thaw it below (otherwise it will
1678 * be frozen forever).
1680 * We also want to do a freeze if we have any params to set,
1681 * even on a non-newly_constructed object.
1683 * It's possible that we have the case of non-newly created
1684 * singleton and all of the passed-in params were construct
1685 * properties so n_params > 0 but we will actually set no
1686 * properties. This is a pretty lame case to optimise, so
1687 * just ignore it and freeze anyway.
1689 if (newly_constructed || n_params)
1690 nqueue = g_object_notify_queue_freeze (object, FALSE);
1692 /* Remember: if it was newly_constructed then g_object_init()
1693 * already did a freeze, so we now have two. Release one.
1695 if (newly_constructed)
1696 g_object_notify_queue_thaw (object, nqueue);
1699 /* run 'constructed' handler if there is a custom one */
1700 if (newly_constructed && CLASS_HAS_CUSTOM_CONSTRUCTED (class))
1701 class->constructed (object);
1703 /* set remaining properties */
1704 for (i = 0; i < n_params; i++)
1705 if (!(params[i].pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY)))
1706 object_set_property (object, params[i].pspec, params[i].value, nqueue);
1708 /* If nqueue is non-NULL then we are frozen. Thaw it. */
1710 g_object_notify_queue_thaw (object, nqueue);
1716 g_object_new_internal (GObjectClass *class,
1717 GObjectConstructParam *params,
1720 GObjectNotifyQueue *nqueue = NULL;
1723 if G_UNLIKELY (CLASS_HAS_CUSTOM_CONSTRUCTOR (class))
1724 return g_object_new_with_custom_constructor (class, params, n_params);
1726 object = (GObject *) g_type_create_instance (class->g_type_class.g_type);
1728 if (CLASS_HAS_PROPS (class))
1732 /* This will have been setup in g_object_init() */
1733 nqueue = g_datalist_id_get_data (&object->qdata, quark_notify_queue);
1734 g_assert (nqueue != NULL);
1736 /* We will set exactly n_construct_properties construct
1737 * properties, but they may come from either the class default
1738 * values or the passed-in parameter list.
1740 for (node = class->construct_properties; node; node = node->next)
1742 const GValue *value;
1747 value = NULL; /* to silence gcc... */
1749 for (j = 0; j < n_params; j++)
1750 if (params[j].pspec == pspec)
1752 value = params[j].value;
1757 value = g_param_spec_get_default_value (pspec);
1759 object_set_property (object, pspec, value, nqueue);
1763 /* run 'constructed' handler if there is a custom one */
1764 if (CLASS_HAS_CUSTOM_CONSTRUCTED (class))
1765 class->constructed (object);
1771 /* Set remaining properties. The construct properties will
1772 * already have been taken, so set only the non-construct
1775 for (i = 0; i < n_params; i++)
1776 if (!(params[i].pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY)))
1777 object_set_property (object, params[i].pspec, params[i].value, nqueue);
1779 g_object_notify_queue_thaw (object, nqueue);
1787 * @object_type: the type id of the #GObject subtype to instantiate
1788 * @n_parameters: the length of the @parameters array
1789 * @parameters: (array length=n_parameters): an array of #GParameter
1791 * Creates a new instance of a #GObject subtype and sets its properties.
1793 * Construction parameters (see #G_PARAM_CONSTRUCT, #G_PARAM_CONSTRUCT_ONLY)
1794 * which are not explicitly specified are set to their default values.
1796 * Rename to: g_object_new
1797 * Returns: (type GObject.Object) (transfer full): a new instance of
1801 g_object_newv (GType object_type,
1803 GParameter *parameters)
1805 GObjectClass *class, *unref_class = NULL;
1808 g_return_val_if_fail (G_TYPE_IS_OBJECT (object_type), NULL);
1809 g_return_val_if_fail (n_parameters == 0 || parameters != NULL, NULL);
1811 /* Try to avoid thrashing the ref_count if we don't need to (since
1812 * it's a locked operation).
1814 class = g_type_class_peek_static (object_type);
1817 class = unref_class = g_type_class_ref (object_type);
1821 GObjectConstructParam *cparams;
1824 cparams = g_newa (GObjectConstructParam, n_parameters);
1827 for (i = 0; i < n_parameters; i++)
1832 pspec = g_param_spec_pool_lookup (pspec_pool, parameters[i].name, object_type, TRUE);
1834 if G_UNLIKELY (!pspec)
1836 g_critical ("%s: object class `%s' has no property named `%s'",
1837 G_STRFUNC, g_type_name (object_type), parameters[i].name);
1841 if G_UNLIKELY (~pspec->flags & G_PARAM_WRITABLE)
1843 g_critical ("%s: property `%s' of object class `%s' is not writable",
1844 G_STRFUNC, pspec->name, g_type_name (object_type));
1848 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
1850 for (k = 0; k < j; k++)
1851 if (cparams[k].pspec == pspec)
1853 if G_UNLIKELY (k != j)
1855 g_critical ("%s: construct property `%s' for type `%s' cannot be set twice",
1856 G_STRFUNC, parameters[i].name, g_type_name (object_type));
1861 cparams[j].pspec = pspec;
1862 cparams[j].value = ¶meters[i].value;
1866 object = g_object_new_internal (class, cparams, j);
1869 /* Fast case: no properties passed in. */
1870 object = g_object_new_internal (class, NULL, 0);
1873 g_type_class_unref (unref_class);
1879 * g_object_new_valist: (skip)
1880 * @object_type: the type id of the #GObject subtype to instantiate
1881 * @first_property_name: the name of the first property
1882 * @var_args: the value of the first property, followed optionally by more
1883 * name/value pairs, followed by %NULL
1885 * Creates a new instance of a #GObject subtype and sets its properties.
1887 * Construction parameters (see #G_PARAM_CONSTRUCT, #G_PARAM_CONSTRUCT_ONLY)
1888 * which are not explicitly specified are set to their default values.
1890 * Returns: a new instance of @object_type
1893 g_object_new_valist (GType object_type,
1894 const gchar *first_property_name,
1897 GObjectClass *class, *unref_class = NULL;
1900 g_return_val_if_fail (G_TYPE_IS_OBJECT (object_type), NULL);
1902 /* Try to avoid thrashing the ref_count if we don't need to (since
1903 * it's a locked operation).
1905 class = g_type_class_peek_static (object_type);
1908 class = unref_class = g_type_class_ref (object_type);
1910 if (first_property_name)
1912 GObjectConstructParam stack_params[16];
1913 GObjectConstructParam *params;
1917 name = first_property_name;
1918 params = stack_params;
1922 gchar *error = NULL;
1926 pspec = g_param_spec_pool_lookup (pspec_pool, name, object_type, TRUE);
1928 if G_UNLIKELY (!pspec)
1930 g_critical ("%s: object class `%s' has no property named `%s'",
1931 G_STRFUNC, g_type_name (object_type), name);
1932 /* Can't continue because arg list will be out of sync. */
1936 if G_UNLIKELY (~pspec->flags & G_PARAM_WRITABLE)
1938 g_critical ("%s: property `%s' of object class `%s' is not writable",
1939 G_STRFUNC, pspec->name, g_type_name (object_type));
1943 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
1945 for (i = 0; i < n_params; i++)
1946 if (params[i].pspec == pspec)
1948 if G_UNLIKELY (i != n_params)
1950 g_critical ("%s: property `%s' for type `%s' cannot be set twice",
1951 G_STRFUNC, name, g_type_name (object_type));
1958 params = g_new (GObjectConstructParam, n_params + 1);
1959 memcpy (params, stack_params, sizeof stack_params);
1961 else if (n_params > 16)
1962 params = g_renew (GObjectConstructParam, params, n_params + 1);
1964 params[n_params].pspec = pspec;
1965 params[n_params].value = g_newa (GValue, 1);
1966 memset (params[n_params].value, 0, sizeof (GValue));
1968 G_VALUE_COLLECT_INIT (params[n_params].value, pspec->value_type, var_args, 0, &error);
1972 g_critical ("%s: %s", G_STRFUNC, error);
1973 g_value_unset (params[n_params].value);
1980 while ((name = va_arg (var_args, const gchar *)));
1982 object = g_object_new_internal (class, params, n_params);
1985 g_value_unset (params[n_params].value);
1987 if (params != stack_params)
1991 /* Fast case: no properties passed in. */
1992 object = g_object_new_internal (class, NULL, 0);
1995 g_type_class_unref (unref_class);
2001 g_object_constructor (GType type,
2002 guint n_construct_properties,
2003 GObjectConstructParam *construct_params)
2008 object = (GObject*) g_type_create_instance (type);
2010 /* set construction parameters */
2011 if (n_construct_properties)
2013 GObjectNotifyQueue *nqueue = g_object_notify_queue_freeze (object, FALSE);
2015 /* set construct properties */
2016 while (n_construct_properties--)
2018 GValue *value = construct_params->value;
2019 GParamSpec *pspec = construct_params->pspec;
2022 object_set_property (object, pspec, value, nqueue);
2024 g_object_notify_queue_thaw (object, nqueue);
2025 /* the notification queue is still frozen from g_object_init(), so
2026 * we don't need to handle it here, g_object_newv() takes
2035 g_object_constructed (GObject *object)
2037 /* empty default impl to allow unconditional upchaining */
2041 * g_object_set_valist: (skip)
2042 * @object: a #GObject
2043 * @first_property_name: name of the first property to set
2044 * @var_args: value for the first property, followed optionally by more
2045 * name/value pairs, followed by %NULL
2047 * Sets properties on an object.
2050 g_object_set_valist (GObject *object,
2051 const gchar *first_property_name,
2054 GObjectNotifyQueue *nqueue;
2057 g_return_if_fail (G_IS_OBJECT (object));
2059 g_object_ref (object);
2060 nqueue = g_object_notify_queue_freeze (object, FALSE);
2062 name = first_property_name;
2065 GValue value = G_VALUE_INIT;
2067 gchar *error = NULL;
2069 pspec = g_param_spec_pool_lookup (pspec_pool,
2071 G_OBJECT_TYPE (object),
2075 g_warning ("%s: object class `%s' has no property named `%s'",
2077 G_OBJECT_TYPE_NAME (object),
2081 if (!(pspec->flags & G_PARAM_WRITABLE))
2083 g_warning ("%s: property `%s' of object class `%s' is not writable",
2086 G_OBJECT_TYPE_NAME (object));
2089 if ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) && !object_in_construction_list (object))
2091 g_warning ("%s: construct property \"%s\" for object `%s' can't be set after construction",
2092 G_STRFUNC, pspec->name, G_OBJECT_TYPE_NAME (object));
2096 G_VALUE_COLLECT_INIT (&value, pspec->value_type, var_args,
2100 g_warning ("%s: %s", G_STRFUNC, error);
2102 g_value_unset (&value);
2106 object_set_property (object, pspec, &value, nqueue);
2107 g_value_unset (&value);
2109 name = va_arg (var_args, gchar*);
2112 g_object_notify_queue_thaw (object, nqueue);
2113 g_object_unref (object);
2117 * g_object_get_valist: (skip)
2118 * @object: a #GObject
2119 * @first_property_name: name of the first property to get
2120 * @var_args: return location for the first property, followed optionally by more
2121 * name/return location pairs, followed by %NULL
2123 * Gets properties of an object.
2125 * In general, a copy is made of the property contents and the caller
2126 * is responsible for freeing the memory in the appropriate manner for
2127 * the type, for instance by calling g_free() or g_object_unref().
2129 * See g_object_get().
2132 g_object_get_valist (GObject *object,
2133 const gchar *first_property_name,
2138 g_return_if_fail (G_IS_OBJECT (object));
2140 g_object_ref (object);
2142 name = first_property_name;
2146 GValue value = G_VALUE_INIT;
2150 pspec = g_param_spec_pool_lookup (pspec_pool,
2152 G_OBJECT_TYPE (object),
2156 g_warning ("%s: object class `%s' has no property named `%s'",
2158 G_OBJECT_TYPE_NAME (object),
2162 if (!(pspec->flags & G_PARAM_READABLE))
2164 g_warning ("%s: property `%s' of object class `%s' is not readable",
2167 G_OBJECT_TYPE_NAME (object));
2171 g_value_init (&value, pspec->value_type);
2173 object_get_property (object, pspec, &value);
2175 G_VALUE_LCOPY (&value, var_args, 0, &error);
2178 g_warning ("%s: %s", G_STRFUNC, error);
2180 g_value_unset (&value);
2184 g_value_unset (&value);
2186 name = va_arg (var_args, gchar*);
2189 g_object_unref (object);
2193 * g_object_set: (skip)
2194 * @object: a #GObject
2195 * @first_property_name: name of the first property to set
2196 * @...: value for the first property, followed optionally by more
2197 * name/value pairs, followed by %NULL
2199 * Sets properties on an object.
2202 g_object_set (gpointer _object,
2203 const gchar *first_property_name,
2206 GObject *object = _object;
2209 g_return_if_fail (G_IS_OBJECT (object));
2211 va_start (var_args, first_property_name);
2212 g_object_set_valist (object, first_property_name, var_args);
2217 * g_object_get: (skip)
2218 * @object: a #GObject
2219 * @first_property_name: name of the first property to get
2220 * @...: return location for the first property, followed optionally by more
2221 * name/return location pairs, followed by %NULL
2223 * Gets properties of an object.
2225 * In general, a copy is made of the property contents and the caller
2226 * is responsible for freeing the memory in the appropriate manner for
2227 * the type, for instance by calling g_free() or g_object_unref().
2230 * <title>Using g_object_get(<!-- -->)</title>
2231 * An example of using g_object_get() to get the contents
2232 * of three properties - one of type #G_TYPE_INT,
2233 * one of type #G_TYPE_STRING, and one of type #G_TYPE_OBJECT:
2239 * g_object_get (my_object,
2240 * "int-property", &intval,
2241 * "str-property", &strval,
2242 * "obj-property", &objval,
2245 * // Do something with intval, strval, objval
2248 * g_object_unref (objval);
2253 g_object_get (gpointer _object,
2254 const gchar *first_property_name,
2257 GObject *object = _object;
2260 g_return_if_fail (G_IS_OBJECT (object));
2262 va_start (var_args, first_property_name);
2263 g_object_get_valist (object, first_property_name, var_args);
2268 * g_object_set_property:
2269 * @object: a #GObject
2270 * @property_name: the name of the property to set
2273 * Sets a property on an object.
2276 g_object_set_property (GObject *object,
2277 const gchar *property_name,
2278 const GValue *value)
2280 GObjectNotifyQueue *nqueue;
2283 g_return_if_fail (G_IS_OBJECT (object));
2284 g_return_if_fail (property_name != NULL);
2285 g_return_if_fail (G_IS_VALUE (value));
2287 g_object_ref (object);
2288 nqueue = g_object_notify_queue_freeze (object, FALSE);
2290 pspec = g_param_spec_pool_lookup (pspec_pool,
2292 G_OBJECT_TYPE (object),
2295 g_warning ("%s: object class `%s' has no property named `%s'",
2297 G_OBJECT_TYPE_NAME (object),
2299 else if (!(pspec->flags & G_PARAM_WRITABLE))
2300 g_warning ("%s: property `%s' of object class `%s' is not writable",
2303 G_OBJECT_TYPE_NAME (object));
2304 else if ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) && !object_in_construction_list (object))
2305 g_warning ("%s: construct property \"%s\" for object `%s' can't be set after construction",
2306 G_STRFUNC, pspec->name, G_OBJECT_TYPE_NAME (object));
2308 object_set_property (object, pspec, value, nqueue);
2310 g_object_notify_queue_thaw (object, nqueue);
2311 g_object_unref (object);
2315 * g_object_get_property:
2316 * @object: a #GObject
2317 * @property_name: the name of the property to get
2318 * @value: return location for the property value
2320 * Gets a property of an object. @value must have been initialized to the
2321 * expected type of the property (or a type to which the expected type can be
2322 * transformed) using g_value_init().
2324 * In general, a copy is made of the property contents and the caller is
2325 * responsible for freeing the memory by calling g_value_unset().
2327 * Note that g_object_get_property() is really intended for language
2328 * bindings, g_object_get() is much more convenient for C programming.
2331 g_object_get_property (GObject *object,
2332 const gchar *property_name,
2337 g_return_if_fail (G_IS_OBJECT (object));
2338 g_return_if_fail (property_name != NULL);
2339 g_return_if_fail (G_IS_VALUE (value));
2341 g_object_ref (object);
2343 pspec = g_param_spec_pool_lookup (pspec_pool,
2345 G_OBJECT_TYPE (object),
2348 g_warning ("%s: object class `%s' has no property named `%s'",
2350 G_OBJECT_TYPE_NAME (object),
2352 else if (!(pspec->flags & G_PARAM_READABLE))
2353 g_warning ("%s: property `%s' of object class `%s' is not readable",
2356 G_OBJECT_TYPE_NAME (object));
2359 GValue *prop_value, tmp_value = G_VALUE_INIT;
2361 /* auto-conversion of the callers value type
2363 if (G_VALUE_TYPE (value) == pspec->value_type)
2365 g_value_reset (value);
2368 else if (!g_value_type_transformable (pspec->value_type, G_VALUE_TYPE (value)))
2370 g_warning ("%s: can't retrieve property `%s' of type `%s' as value of type `%s'",
2371 G_STRFUNC, pspec->name,
2372 g_type_name (pspec->value_type),
2373 G_VALUE_TYPE_NAME (value));
2374 g_object_unref (object);
2379 g_value_init (&tmp_value, pspec->value_type);
2380 prop_value = &tmp_value;
2382 object_get_property (object, pspec, prop_value);
2383 if (prop_value != value)
2385 g_value_transform (prop_value, value);
2386 g_value_unset (&tmp_value);
2390 g_object_unref (object);
2394 * g_object_connect: (skip)
2395 * @object: a #GObject
2396 * @signal_spec: the spec for the first signal
2397 * @...: #GCallback for the first signal, followed by data for the
2398 * first signal, followed optionally by more signal
2399 * spec/callback/data triples, followed by %NULL
2401 * A convenience function to connect multiple signals at once.
2403 * The signal specs expected by this function have the form
2404 * "modifier::signal_name", where modifier can be one of the following:
2407 * <term>signal</term>
2409 * equivalent to <literal>g_signal_connect_data (..., NULL, 0)</literal>
2410 * </para></listitem>
2413 * <term>object_signal</term>
2414 * <term>object-signal</term>
2416 * equivalent to <literal>g_signal_connect_object (..., 0)</literal>
2417 * </para></listitem>
2420 * <term>swapped_signal</term>
2421 * <term>swapped-signal</term>
2423 * equivalent to <literal>g_signal_connect_data (..., NULL, G_CONNECT_SWAPPED)</literal>
2424 * </para></listitem>
2427 * <term>swapped_object_signal</term>
2428 * <term>swapped-object-signal</term>
2430 * equivalent to <literal>g_signal_connect_object (..., G_CONNECT_SWAPPED)</literal>
2431 * </para></listitem>
2434 * <term>signal_after</term>
2435 * <term>signal-after</term>
2437 * equivalent to <literal>g_signal_connect_data (..., NULL, G_CONNECT_AFTER)</literal>
2438 * </para></listitem>
2441 * <term>object_signal_after</term>
2442 * <term>object-signal-after</term>
2444 * equivalent to <literal>g_signal_connect_object (..., G_CONNECT_AFTER)</literal>
2445 * </para></listitem>
2448 * <term>swapped_signal_after</term>
2449 * <term>swapped-signal-after</term>
2451 * equivalent to <literal>g_signal_connect_data (..., NULL, G_CONNECT_SWAPPED | G_CONNECT_AFTER)</literal>
2452 * </para></listitem>
2455 * <term>swapped_object_signal_after</term>
2456 * <term>swapped-object-signal-after</term>
2458 * equivalent to <literal>g_signal_connect_object (..., G_CONNECT_SWAPPED | G_CONNECT_AFTER)</literal>
2459 * </para></listitem>
2464 * menu->toplevel = g_object_connect (g_object_new (GTK_TYPE_WINDOW,
2465 * "type", GTK_WINDOW_POPUP,
2468 * "signal::event", gtk_menu_window_event, menu,
2469 * "signal::size_request", gtk_menu_window_size_request, menu,
2470 * "signal::destroy", gtk_widget_destroyed, &menu->toplevel,
2474 * Returns: (transfer none): @object
2477 g_object_connect (gpointer _object,
2478 const gchar *signal_spec,
2481 GObject *object = _object;
2484 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
2485 g_return_val_if_fail (object->ref_count > 0, object);
2487 va_start (var_args, signal_spec);
2490 GCallback callback = va_arg (var_args, GCallback);
2491 gpointer data = va_arg (var_args, gpointer);
2493 if (strncmp (signal_spec, "signal::", 8) == 0)
2494 g_signal_connect_data (object, signal_spec + 8,
2495 callback, data, NULL,
2497 else if (strncmp (signal_spec, "object_signal::", 15) == 0 ||
2498 strncmp (signal_spec, "object-signal::", 15) == 0)
2499 g_signal_connect_object (object, signal_spec + 15,
2502 else if (strncmp (signal_spec, "swapped_signal::", 16) == 0 ||
2503 strncmp (signal_spec, "swapped-signal::", 16) == 0)
2504 g_signal_connect_data (object, signal_spec + 16,
2505 callback, data, NULL,
2507 else if (strncmp (signal_spec, "swapped_object_signal::", 23) == 0 ||
2508 strncmp (signal_spec, "swapped-object-signal::", 23) == 0)
2509 g_signal_connect_object (object, signal_spec + 23,
2512 else if (strncmp (signal_spec, "signal_after::", 14) == 0 ||
2513 strncmp (signal_spec, "signal-after::", 14) == 0)
2514 g_signal_connect_data (object, signal_spec + 14,
2515 callback, data, NULL,
2517 else if (strncmp (signal_spec, "object_signal_after::", 21) == 0 ||
2518 strncmp (signal_spec, "object-signal-after::", 21) == 0)
2519 g_signal_connect_object (object, signal_spec + 21,
2522 else if (strncmp (signal_spec, "swapped_signal_after::", 22) == 0 ||
2523 strncmp (signal_spec, "swapped-signal-after::", 22) == 0)
2524 g_signal_connect_data (object, signal_spec + 22,
2525 callback, data, NULL,
2526 G_CONNECT_SWAPPED | G_CONNECT_AFTER);
2527 else if (strncmp (signal_spec, "swapped_object_signal_after::", 29) == 0 ||
2528 strncmp (signal_spec, "swapped-object-signal-after::", 29) == 0)
2529 g_signal_connect_object (object, signal_spec + 29,
2531 G_CONNECT_SWAPPED | G_CONNECT_AFTER);
2534 g_warning ("%s: invalid signal spec \"%s\"", G_STRFUNC, signal_spec);
2537 signal_spec = va_arg (var_args, gchar*);
2545 * g_object_disconnect: (skip)
2546 * @object: a #GObject
2547 * @signal_spec: the spec for the first signal
2548 * @...: #GCallback for the first signal, followed by data for the first signal,
2549 * followed optionally by more signal spec/callback/data triples,
2552 * A convenience function to disconnect multiple signals at once.
2554 * The signal specs expected by this function have the form
2555 * "any_signal", which means to disconnect any signal with matching
2556 * callback and data, or "any_signal::signal_name", which only
2557 * disconnects the signal named "signal_name".
2560 g_object_disconnect (gpointer _object,
2561 const gchar *signal_spec,
2564 GObject *object = _object;
2567 g_return_if_fail (G_IS_OBJECT (object));
2568 g_return_if_fail (object->ref_count > 0);
2570 va_start (var_args, signal_spec);
2573 GCallback callback = va_arg (var_args, GCallback);
2574 gpointer data = va_arg (var_args, gpointer);
2575 guint sid = 0, detail = 0, mask = 0;
2577 if (strncmp (signal_spec, "any_signal::", 12) == 0 ||
2578 strncmp (signal_spec, "any-signal::", 12) == 0)
2581 mask = G_SIGNAL_MATCH_ID | G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA;
2583 else if (strcmp (signal_spec, "any_signal") == 0 ||
2584 strcmp (signal_spec, "any-signal") == 0)
2587 mask = G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA;
2591 g_warning ("%s: invalid signal spec \"%s\"", G_STRFUNC, signal_spec);
2595 if ((mask & G_SIGNAL_MATCH_ID) &&
2596 !g_signal_parse_name (signal_spec, G_OBJECT_TYPE (object), &sid, &detail, FALSE))
2597 g_warning ("%s: invalid signal name \"%s\"", G_STRFUNC, signal_spec);
2598 else if (!g_signal_handlers_disconnect_matched (object, mask | (detail ? G_SIGNAL_MATCH_DETAIL : 0),
2600 NULL, (gpointer)callback, data))
2601 g_warning ("%s: signal handler %p(%p) is not connected", G_STRFUNC, callback, data);
2602 signal_spec = va_arg (var_args, gchar*);
2613 } weak_refs[1]; /* flexible array */
2617 weak_refs_notify (gpointer data)
2619 WeakRefStack *wstack = data;
2622 for (i = 0; i < wstack->n_weak_refs; i++)
2623 wstack->weak_refs[i].notify (wstack->weak_refs[i].data, wstack->object);
2628 * g_object_weak_ref: (skip)
2629 * @object: #GObject to reference weakly
2630 * @notify: callback to invoke before the object is freed
2631 * @data: extra data to pass to notify
2633 * Adds a weak reference callback to an object. Weak references are
2634 * used for notification when an object is finalized. They are called
2635 * "weak references" because they allow you to safely hold a pointer
2636 * to an object without calling g_object_ref() (g_object_ref() adds a
2637 * strong reference, that is, forces the object to stay alive).
2639 * Note that the weak references created by this method are not
2640 * thread-safe: they cannot safely be used in one thread if the
2641 * object's last g_object_unref() might happen in another thread.
2642 * Use #GWeakRef if thread-safety is required.
2645 g_object_weak_ref (GObject *object,
2649 WeakRefStack *wstack;
2652 g_return_if_fail (G_IS_OBJECT (object));
2653 g_return_if_fail (notify != NULL);
2654 g_return_if_fail (object->ref_count >= 1);
2656 G_LOCK (weak_refs_mutex);
2657 wstack = g_datalist_id_remove_no_notify (&object->qdata, quark_weak_refs);
2660 i = wstack->n_weak_refs++;
2661 wstack = g_realloc (wstack, sizeof (*wstack) + sizeof (wstack->weak_refs[0]) * i);
2665 wstack = g_renew (WeakRefStack, NULL, 1);
2666 wstack->object = object;
2667 wstack->n_weak_refs = 1;
2670 wstack->weak_refs[i].notify = notify;
2671 wstack->weak_refs[i].data = data;
2672 g_datalist_id_set_data_full (&object->qdata, quark_weak_refs, wstack, weak_refs_notify);
2673 G_UNLOCK (weak_refs_mutex);
2677 * g_object_weak_unref: (skip)
2678 * @object: #GObject to remove a weak reference from
2679 * @notify: callback to search for
2680 * @data: data to search for
2682 * Removes a weak reference callback to an object.
2685 g_object_weak_unref (GObject *object,
2689 WeakRefStack *wstack;
2690 gboolean found_one = FALSE;
2692 g_return_if_fail (G_IS_OBJECT (object));
2693 g_return_if_fail (notify != NULL);
2695 G_LOCK (weak_refs_mutex);
2696 wstack = g_datalist_id_get_data (&object->qdata, quark_weak_refs);
2701 for (i = 0; i < wstack->n_weak_refs; i++)
2702 if (wstack->weak_refs[i].notify == notify &&
2703 wstack->weak_refs[i].data == data)
2706 wstack->n_weak_refs -= 1;
2707 if (i != wstack->n_weak_refs)
2708 wstack->weak_refs[i] = wstack->weak_refs[wstack->n_weak_refs];
2713 G_UNLOCK (weak_refs_mutex);
2715 g_warning ("%s: couldn't find weak ref %p(%p)", G_STRFUNC, notify, data);
2719 * g_object_add_weak_pointer: (skip)
2720 * @object: The object that should be weak referenced.
2721 * @weak_pointer_location: (inout): The memory address of a pointer.
2723 * Adds a weak reference from weak_pointer to @object to indicate that
2724 * the pointer located at @weak_pointer_location is only valid during
2725 * the lifetime of @object. When the @object is finalized,
2726 * @weak_pointer will be set to %NULL.
2728 * Note that as with g_object_weak_ref(), the weak references created by
2729 * this method are not thread-safe: they cannot safely be used in one
2730 * thread if the object's last g_object_unref() might happen in another
2731 * thread. Use #GWeakRef if thread-safety is required.
2734 g_object_add_weak_pointer (GObject *object,
2735 gpointer *weak_pointer_location)
2737 g_return_if_fail (G_IS_OBJECT (object));
2738 g_return_if_fail (weak_pointer_location != NULL);
2740 g_object_weak_ref (object,
2741 (GWeakNotify) g_nullify_pointer,
2742 weak_pointer_location);
2746 * g_object_remove_weak_pointer: (skip)
2747 * @object: The object that is weak referenced.
2748 * @weak_pointer_location: (inout): The memory address of a pointer.
2750 * Removes a weak reference from @object that was previously added
2751 * using g_object_add_weak_pointer(). The @weak_pointer_location has
2752 * to match the one used with g_object_add_weak_pointer().
2755 g_object_remove_weak_pointer (GObject *object,
2756 gpointer *weak_pointer_location)
2758 g_return_if_fail (G_IS_OBJECT (object));
2759 g_return_if_fail (weak_pointer_location != NULL);
2761 g_object_weak_unref (object,
2762 (GWeakNotify) g_nullify_pointer,
2763 weak_pointer_location);
2767 object_floating_flag_handler (GObject *object,
2773 case +1: /* force floating if possible */
2775 oldvalue = g_atomic_pointer_get (&object->qdata);
2776 while (!g_atomic_pointer_compare_and_exchange ((void**) &object->qdata, oldvalue,
2777 (gpointer) ((gsize) oldvalue | OBJECT_FLOATING_FLAG)));
2778 return (gsize) oldvalue & OBJECT_FLOATING_FLAG;
2779 case -1: /* sink if possible */
2781 oldvalue = g_atomic_pointer_get (&object->qdata);
2782 while (!g_atomic_pointer_compare_and_exchange ((void**) &object->qdata, oldvalue,
2783 (gpointer) ((gsize) oldvalue & ~(gsize) OBJECT_FLOATING_FLAG)));
2784 return (gsize) oldvalue & OBJECT_FLOATING_FLAG;
2785 default: /* check floating */
2786 return 0 != ((gsize) g_atomic_pointer_get (&object->qdata) & OBJECT_FLOATING_FLAG);
2791 * g_object_is_floating:
2792 * @object: (type GObject.Object): a #GObject
2794 * Checks whether @object has a <link linkend="floating-ref">floating</link>
2799 * Returns: %TRUE if @object has a floating reference
2802 g_object_is_floating (gpointer _object)
2804 GObject *object = _object;
2805 g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
2806 return floating_flag_handler (object, 0);
2810 * g_object_ref_sink:
2811 * @object: (type GObject.Object): a #GObject
2813 * Increase the reference count of @object, and possibly remove the
2814 * <link linkend="floating-ref">floating</link> reference, if @object
2815 * has a floating reference.
2817 * In other words, if the object is floating, then this call "assumes
2818 * ownership" of the floating reference, converting it to a normal
2819 * reference by clearing the floating flag while leaving the reference
2820 * count unchanged. If the object is not floating, then this call
2821 * adds a new normal reference increasing the reference count by one.
2825 * Returns: (type GObject.Object) (transfer none): @object
2828 g_object_ref_sink (gpointer _object)
2830 GObject *object = _object;
2831 gboolean was_floating;
2832 g_return_val_if_fail (G_IS_OBJECT (object), object);
2833 g_return_val_if_fail (object->ref_count >= 1, object);
2834 g_object_ref (object);
2835 was_floating = floating_flag_handler (object, -1);
2837 g_object_unref (object);
2842 * g_object_force_floating:
2843 * @object: a #GObject
2845 * This function is intended for #GObject implementations to re-enforce a
2846 * <link linkend="floating-ref">floating</link> object reference.
2847 * Doing this is seldom required: all
2848 * #GInitiallyUnowned<!-- -->s are created with a floating reference which
2849 * usually just needs to be sunken by calling g_object_ref_sink().
2854 g_object_force_floating (GObject *object)
2856 g_return_if_fail (G_IS_OBJECT (object));
2857 g_return_if_fail (object->ref_count >= 1);
2859 floating_flag_handler (object, +1);
2864 guint n_toggle_refs;
2866 GToggleNotify notify;
2868 } toggle_refs[1]; /* flexible array */
2872 toggle_refs_notify (GObject *object,
2873 gboolean is_last_ref)
2875 ToggleRefStack tstack, *tstackptr;
2877 G_LOCK (toggle_refs_mutex);
2878 tstackptr = g_datalist_id_get_data (&object->qdata, quark_toggle_refs);
2879 tstack = *tstackptr;
2880 G_UNLOCK (toggle_refs_mutex);
2882 /* Reentrancy here is not as tricky as it seems, because a toggle reference
2883 * will only be notified when there is exactly one of them.
2885 g_assert (tstack.n_toggle_refs == 1);
2886 tstack.toggle_refs[0].notify (tstack.toggle_refs[0].data, tstack.object, is_last_ref);
2890 * g_object_add_toggle_ref: (skip)
2891 * @object: a #GObject
2892 * @notify: a function to call when this reference is the
2893 * last reference to the object, or is no longer
2894 * the last reference.
2895 * @data: data to pass to @notify
2897 * Increases the reference count of the object by one and sets a
2898 * callback to be called when all other references to the object are
2899 * dropped, or when this is already the last reference to the object
2900 * and another reference is established.
2902 * This functionality is intended for binding @object to a proxy
2903 * object managed by another memory manager. This is done with two
2904 * paired references: the strong reference added by
2905 * g_object_add_toggle_ref() and a reverse reference to the proxy
2906 * object which is either a strong reference or weak reference.
2908 * The setup is that when there are no other references to @object,
2909 * only a weak reference is held in the reverse direction from @object
2910 * to the proxy object, but when there are other references held to
2911 * @object, a strong reference is held. The @notify callback is called
2912 * when the reference from @object to the proxy object should be
2913 * <firstterm>toggled</firstterm> from strong to weak (@is_last_ref
2914 * true) or weak to strong (@is_last_ref false).
2916 * Since a (normal) reference must be held to the object before
2917 * calling g_object_add_toggle_ref(), the initial state of the reverse
2918 * link is always strong.
2920 * Multiple toggle references may be added to the same gobject,
2921 * however if there are multiple toggle references to an object, none
2922 * of them will ever be notified until all but one are removed. For
2923 * this reason, you should only ever use a toggle reference if there
2924 * is important state in the proxy object.
2929 g_object_add_toggle_ref (GObject *object,
2930 GToggleNotify notify,
2933 ToggleRefStack *tstack;
2936 g_return_if_fail (G_IS_OBJECT (object));
2937 g_return_if_fail (notify != NULL);
2938 g_return_if_fail (object->ref_count >= 1);
2940 g_object_ref (object);
2942 G_LOCK (toggle_refs_mutex);
2943 tstack = g_datalist_id_remove_no_notify (&object->qdata, quark_toggle_refs);
2946 i = tstack->n_toggle_refs++;
2947 /* allocate i = tstate->n_toggle_refs - 1 positions beyond the 1 declared
2948 * in tstate->toggle_refs */
2949 tstack = g_realloc (tstack, sizeof (*tstack) + sizeof (tstack->toggle_refs[0]) * i);
2953 tstack = g_renew (ToggleRefStack, NULL, 1);
2954 tstack->object = object;
2955 tstack->n_toggle_refs = 1;
2959 /* Set a flag for fast lookup after adding the first toggle reference */
2960 if (tstack->n_toggle_refs == 1)
2961 g_datalist_set_flags (&object->qdata, OBJECT_HAS_TOGGLE_REF_FLAG);
2963 tstack->toggle_refs[i].notify = notify;
2964 tstack->toggle_refs[i].data = data;
2965 g_datalist_id_set_data_full (&object->qdata, quark_toggle_refs, tstack,
2966 (GDestroyNotify)g_free);
2967 G_UNLOCK (toggle_refs_mutex);
2971 * g_object_remove_toggle_ref: (skip)
2972 * @object: a #GObject
2973 * @notify: a function to call when this reference is the
2974 * last reference to the object, or is no longer
2975 * the last reference.
2976 * @data: data to pass to @notify
2978 * Removes a reference added with g_object_add_toggle_ref(). The
2979 * reference count of the object is decreased by one.
2984 g_object_remove_toggle_ref (GObject *object,
2985 GToggleNotify notify,
2988 ToggleRefStack *tstack;
2989 gboolean found_one = FALSE;
2991 g_return_if_fail (G_IS_OBJECT (object));
2992 g_return_if_fail (notify != NULL);
2994 G_LOCK (toggle_refs_mutex);
2995 tstack = g_datalist_id_get_data (&object->qdata, quark_toggle_refs);
3000 for (i = 0; i < tstack->n_toggle_refs; i++)
3001 if (tstack->toggle_refs[i].notify == notify &&
3002 tstack->toggle_refs[i].data == data)
3005 tstack->n_toggle_refs -= 1;
3006 if (i != tstack->n_toggle_refs)
3007 tstack->toggle_refs[i] = tstack->toggle_refs[tstack->n_toggle_refs];
3009 if (tstack->n_toggle_refs == 0)
3010 g_datalist_unset_flags (&object->qdata, OBJECT_HAS_TOGGLE_REF_FLAG);
3015 G_UNLOCK (toggle_refs_mutex);
3018 g_object_unref (object);
3020 g_warning ("%s: couldn't find toggle ref %p(%p)", G_STRFUNC, notify, data);
3025 * @object: (type GObject.Object): a #GObject
3027 * Increases the reference count of @object.
3029 * Returns: (type GObject.Object) (transfer none): the same @object
3032 g_object_ref (gpointer _object)
3034 GObject *object = _object;
3037 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3038 g_return_val_if_fail (object->ref_count > 0, NULL);
3040 #ifdef G_ENABLE_DEBUG
3041 if (g_trap_object_ref == object)
3043 #endif /* G_ENABLE_DEBUG */
3046 old_val = g_atomic_int_add (&object->ref_count, 1);
3048 if (old_val == 1 && OBJECT_HAS_TOGGLE_REF (object))
3049 toggle_refs_notify (object, FALSE);
3051 TRACE (GOBJECT_OBJECT_REF(object,G_TYPE_FROM_INSTANCE(object),old_val));
3058 * @object: (type GObject.Object): a #GObject
3060 * Decreases the reference count of @object. When its reference count
3061 * drops to 0, the object is finalized (i.e. its memory is freed).
3064 g_object_unref (gpointer _object)
3066 GObject *object = _object;
3069 g_return_if_fail (G_IS_OBJECT (object));
3070 g_return_if_fail (object->ref_count > 0);
3072 #ifdef G_ENABLE_DEBUG
3073 if (g_trap_object_ref == object)
3075 #endif /* G_ENABLE_DEBUG */
3077 /* here we want to atomically do: if (ref_count>1) { ref_count--; return; } */
3078 retry_atomic_decrement1:
3079 old_ref = g_atomic_int_get (&object->ref_count);
3082 /* valid if last 2 refs are owned by this call to unref and the toggle_ref */
3083 gboolean has_toggle_ref = OBJECT_HAS_TOGGLE_REF (object);
3085 if (!g_atomic_int_compare_and_exchange ((int *)&object->ref_count, old_ref, old_ref - 1))
3086 goto retry_atomic_decrement1;
3088 TRACE (GOBJECT_OBJECT_UNREF(object,G_TYPE_FROM_INSTANCE(object),old_ref));
3090 /* if we went from 2->1 we need to notify toggle refs if any */
3091 if (old_ref == 2 && has_toggle_ref) /* The last ref being held in this case is owned by the toggle_ref */
3092 toggle_refs_notify (object, TRUE);
3096 GSList **weak_locations;
3098 /* The only way that this object can live at this point is if
3099 * there are outstanding weak references already established
3100 * before we got here.
3102 * If there were not already weak references then no more can be
3103 * established at this time, because the other thread would have
3104 * to hold a strong ref in order to call
3105 * g_object_add_weak_pointer() and then we wouldn't be here.
3107 weak_locations = g_datalist_id_get_data (&object->qdata, quark_weak_locations);
3109 if (weak_locations != NULL)
3111 g_rw_lock_writer_lock (&weak_locations_lock);
3113 /* It is possible that one of the weak references beat us to
3114 * the lock. Make sure the refcount is still what we expected
3117 old_ref = g_atomic_int_get (&object->ref_count);
3120 g_rw_lock_writer_unlock (&weak_locations_lock);
3121 goto retry_atomic_decrement1;
3124 /* We got the lock first, so the object will definitely die
3125 * now. Clear out all the weak references.
3127 while (*weak_locations)
3129 GWeakRef *weak_ref_location = (*weak_locations)->data;
3131 weak_ref_location->priv.p = NULL;
3132 *weak_locations = g_slist_delete_link (*weak_locations, *weak_locations);
3135 g_rw_lock_writer_unlock (&weak_locations_lock);
3138 /* we are about to remove the last reference */
3139 TRACE (GOBJECT_OBJECT_DISPOSE(object,G_TYPE_FROM_INSTANCE(object), 1));
3140 G_OBJECT_GET_CLASS (object)->dispose (object);
3141 TRACE (GOBJECT_OBJECT_DISPOSE_END(object,G_TYPE_FROM_INSTANCE(object), 1));
3143 /* may have been re-referenced meanwhile */
3144 retry_atomic_decrement2:
3145 old_ref = g_atomic_int_get ((int *)&object->ref_count);
3148 /* valid if last 2 refs are owned by this call to unref and the toggle_ref */
3149 gboolean has_toggle_ref = OBJECT_HAS_TOGGLE_REF (object);
3151 if (!g_atomic_int_compare_and_exchange ((int *)&object->ref_count, old_ref, old_ref - 1))
3152 goto retry_atomic_decrement2;
3154 TRACE (GOBJECT_OBJECT_UNREF(object,G_TYPE_FROM_INSTANCE(object),old_ref));
3156 /* if we went from 2->1 we need to notify toggle refs if any */
3157 if (old_ref == 2 && has_toggle_ref) /* The last ref being held in this case is owned by the toggle_ref */
3158 toggle_refs_notify (object, TRUE);
3163 /* we are still in the process of taking away the last ref */
3164 g_datalist_id_set_data (&object->qdata, quark_closure_array, NULL);
3165 g_signal_handlers_destroy (object);
3166 g_datalist_id_set_data (&object->qdata, quark_weak_refs, NULL);
3168 /* decrement the last reference */
3169 old_ref = g_atomic_int_add (&object->ref_count, -1);
3171 TRACE (GOBJECT_OBJECT_UNREF(object,G_TYPE_FROM_INSTANCE(object),old_ref));
3173 /* may have been re-referenced meanwhile */
3174 if (G_LIKELY (old_ref == 1))
3176 TRACE (GOBJECT_OBJECT_FINALIZE(object,G_TYPE_FROM_INSTANCE(object)));
3177 G_OBJECT_GET_CLASS (object)->finalize (object);
3179 TRACE (GOBJECT_OBJECT_FINALIZE_END(object,G_TYPE_FROM_INSTANCE(object)));
3181 #ifdef G_ENABLE_DEBUG
3184 /* catch objects not chaining finalize handlers */
3185 G_LOCK (debug_objects);
3186 g_assert (g_hash_table_lookup (debug_objects_ht, object) == NULL);
3187 G_UNLOCK (debug_objects);
3189 #endif /* G_ENABLE_DEBUG */
3190 g_type_free_instance ((GTypeInstance*) object);
3196 * g_clear_object: (skip)
3197 * @object_ptr: a pointer to a #GObject reference
3199 * Clears a reference to a #GObject.
3201 * @object_ptr must not be %NULL.
3203 * If the reference is %NULL then this function does nothing.
3204 * Otherwise, the reference count of the object is decreased and the
3205 * pointer is set to %NULL.
3207 * This function is threadsafe and modifies the pointer atomically,
3208 * using memory barriers where needed.
3210 * A macro is also included that allows this function to be used without
3215 #undef g_clear_object
3217 g_clear_object (volatile GObject **object_ptr)
3219 g_clear_pointer (object_ptr, g_object_unref);
3223 * g_object_get_qdata:
3224 * @object: The GObject to get a stored user data pointer from
3225 * @quark: A #GQuark, naming the user data pointer
3227 * This function gets back user data pointers stored via
3228 * g_object_set_qdata().
3230 * Returns: (transfer none): The user data pointer set, or %NULL
3233 g_object_get_qdata (GObject *object,
3236 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3238 return quark ? g_datalist_id_get_data (&object->qdata, quark) : NULL;
3242 * g_object_set_qdata: (skip)
3243 * @object: The GObject to set store a user data pointer
3244 * @quark: A #GQuark, naming the user data pointer
3245 * @data: An opaque user data pointer
3247 * This sets an opaque, named pointer on an object.
3248 * The name is specified through a #GQuark (retrived e.g. via
3249 * g_quark_from_static_string()), and the pointer
3250 * can be gotten back from the @object with g_object_get_qdata()
3251 * until the @object is finalized.
3252 * Setting a previously set user data pointer, overrides (frees)
3253 * the old pointer set, using #NULL as pointer essentially
3254 * removes the data stored.
3257 g_object_set_qdata (GObject *object,
3261 g_return_if_fail (G_IS_OBJECT (object));
3262 g_return_if_fail (quark > 0);
3264 g_datalist_id_set_data (&object->qdata, quark, data);
3268 * g_object_dup_qdata:
3269 * @object: the #GObject to store user data on
3270 * @quark: a #GQuark, naming the user data pointer
3271 * @dup_func: (allow-none): function to dup the value
3272 * @user_data: (allow-none): passed as user_data to @dup_func
3274 * This is a variant of g_object_get_qdata() which returns
3275 * a 'duplicate' of the value. @dup_func defines the
3276 * meaning of 'duplicate' in this context, it could e.g.
3277 * take a reference on a ref-counted object.
3279 * If the @quark is not set on the object then @dup_func
3280 * will be called with a %NULL argument.
3282 * Note that @dup_func is called while user data of @object
3285 * This function can be useful to avoid races when multiple
3286 * threads are using object data on the same key on the same
3289 * Returns: the result of calling @dup_func on the value
3290 * associated with @quark on @object, or %NULL if not set.
3291 * If @dup_func is %NULL, the value is returned
3297 g_object_dup_qdata (GObject *object,
3299 GDuplicateFunc dup_func,
3302 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3303 g_return_val_if_fail (quark > 0, NULL);
3305 return g_datalist_id_dup_data (&object->qdata, quark, dup_func, user_data);
3309 * g_object_replace_qdata:
3310 * @object: the #GObject to store user data on
3311 * @quark: a #GQuark, naming the user data pointer
3312 * @oldval: (allow-none): the old value to compare against
3313 * @newval: (allow-none): the new value
3314 * @destroy: (allow-none): a destroy notify for the new value
3315 * @old_destroy: (allow-none): destroy notify for the existing value
3317 * Compares the user data for the key @quark on @object with
3318 * @oldval, and if they are the same, replaces @oldval with
3321 * This is like a typical atomic compare-and-exchange
3322 * operation, for user data on an object.
3324 * If the previous value was replaced then ownership of the
3325 * old value (@oldval) is passed to the caller, including
3326 * the registred destroy notify for it (passed out in @old_destroy).
3327 * Its up to the caller to free this as he wishes, which may
3328 * or may not include using @old_destroy as sometimes replacement
3329 * should not destroy the object in the normal way.
3331 * Return: %TRUE if the existing value for @quark was replaced
3332 * by @newval, %FALSE otherwise.
3337 g_object_replace_qdata (GObject *object,
3341 GDestroyNotify destroy,
3342 GDestroyNotify *old_destroy)
3344 g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
3345 g_return_val_if_fail (quark > 0, FALSE);
3347 return g_datalist_id_replace_data (&object->qdata, quark,
3348 oldval, newval, destroy,
3353 * g_object_set_qdata_full: (skip)
3354 * @object: The GObject to set store a user data pointer
3355 * @quark: A #GQuark, naming the user data pointer
3356 * @data: An opaque user data pointer
3357 * @destroy: Function to invoke with @data as argument, when @data
3360 * This function works like g_object_set_qdata(), but in addition,
3361 * a void (*destroy) (gpointer) function may be specified which is
3362 * called with @data as argument when the @object is finalized, or
3363 * the data is being overwritten by a call to g_object_set_qdata()
3364 * with the same @quark.
3367 g_object_set_qdata_full (GObject *object,
3370 GDestroyNotify destroy)
3372 g_return_if_fail (G_IS_OBJECT (object));
3373 g_return_if_fail (quark > 0);
3375 g_datalist_id_set_data_full (&object->qdata, quark, data,
3376 data ? destroy : (GDestroyNotify) NULL);
3380 * g_object_steal_qdata:
3381 * @object: The GObject to get a stored user data pointer from
3382 * @quark: A #GQuark, naming the user data pointer
3384 * This function gets back user data pointers stored via
3385 * g_object_set_qdata() and removes the @data from object
3386 * without invoking its destroy() function (if any was
3388 * Usually, calling this function is only required to update
3389 * user data pointers with a destroy notifier, for example:
3392 * object_add_to_user_list (GObject *object,
3393 * const gchar *new_string)
3395 * // the quark, naming the object data
3396 * GQuark quark_string_list = g_quark_from_static_string ("my-string-list");
3397 * // retrive the old string list
3398 * GList *list = g_object_steal_qdata (object, quark_string_list);
3400 * // prepend new string
3401 * list = g_list_prepend (list, g_strdup (new_string));
3402 * // this changed 'list', so we need to set it again
3403 * g_object_set_qdata_full (object, quark_string_list, list, free_string_list);
3406 * free_string_list (gpointer data)
3408 * GList *node, *list = data;
3410 * for (node = list; node; node = node->next)
3411 * g_free (node->data);
3412 * g_list_free (list);
3415 * Using g_object_get_qdata() in the above example, instead of
3416 * g_object_steal_qdata() would have left the destroy function set,
3417 * and thus the partial string list would have been freed upon
3418 * g_object_set_qdata_full().
3420 * Returns: (transfer full): The user data pointer set, or %NULL
3423 g_object_steal_qdata (GObject *object,
3426 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3427 g_return_val_if_fail (quark > 0, NULL);
3429 return g_datalist_id_remove_no_notify (&object->qdata, quark);
3433 * g_object_get_data:
3434 * @object: #GObject containing the associations
3435 * @key: name of the key for that association
3437 * Gets a named field from the objects table of associations (see g_object_set_data()).
3439 * Returns: (transfer none): the data if found, or %NULL if no such data exists.
3442 g_object_get_data (GObject *object,
3445 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3446 g_return_val_if_fail (key != NULL, NULL);
3448 return g_datalist_get_data (&object->qdata, key);
3452 * g_object_set_data:
3453 * @object: #GObject containing the associations.
3454 * @key: name of the key
3455 * @data: data to associate with that key
3457 * Each object carries around a table of associations from
3458 * strings to pointers. This function lets you set an association.
3460 * If the object already had an association with that name,
3461 * the old association will be destroyed.
3464 g_object_set_data (GObject *object,
3468 g_return_if_fail (G_IS_OBJECT (object));
3469 g_return_if_fail (key != NULL);
3471 g_datalist_id_set_data (&object->qdata, g_quark_from_string (key), data);
3475 * g_object_dup_data:
3476 * @object: the #GObject to store user data on
3477 * @key: a string, naming the user data pointer
3478 * @dup_func: (allow-none): function to dup the value
3479 * @user_data: (allow-none): passed as user_data to @dup_func
3481 * This is a variant of g_object_get_data() which returns
3482 * a 'duplicate' of the value. @dup_func defines the
3483 * meaning of 'duplicate' in this context, it could e.g.
3484 * take a reference on a ref-counted object.
3486 * If the @key is not set on the object then @dup_func
3487 * will be called with a %NULL argument.
3489 * Note that @dup_func is called while user data of @object
3492 * This function can be useful to avoid races when multiple
3493 * threads are using object data on the same key on the same
3496 * Returns: the result of calling @dup_func on the value
3497 * associated with @key on @object, or %NULL if not set.
3498 * If @dup_func is %NULL, the value is returned
3504 g_object_dup_data (GObject *object,
3506 GDuplicateFunc dup_func,
3509 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3510 g_return_val_if_fail (key != NULL, NULL);
3512 return g_datalist_id_dup_data (&object->qdata,
3513 g_quark_from_string (key),
3514 dup_func, user_data);
3518 * g_object_replace_data:
3519 * @object: the #GObject to store user data on
3520 * @key: a string, naming the user data pointer
3521 * @oldval: (allow-none): the old value to compare against
3522 * @newval: (allow-none): the new value
3523 * @destroy: (allow-none): a destroy notify for the new value
3524 * @old_destroy: (allow-none): destroy notify for the existing value
3526 * Compares the user data for the key @key on @object with
3527 * @oldval, and if they are the same, replaces @oldval with
3530 * This is like a typical atomic compare-and-exchange
3531 * operation, for user data on an object.
3533 * If the previous value was replaced then ownership of the
3534 * old value (@oldval) is passed to the caller, including
3535 * the registred destroy notify for it (passed out in @old_destroy).
3536 * Its up to the caller to free this as he wishes, which may
3537 * or may not include using @old_destroy as sometimes replacement
3538 * should not destroy the object in the normal way.
3540 * Return: %TRUE if the existing value for @key was replaced
3541 * by @newval, %FALSE otherwise.
3546 g_object_replace_data (GObject *object,
3550 GDestroyNotify destroy,
3551 GDestroyNotify *old_destroy)
3553 g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
3554 g_return_val_if_fail (key != NULL, FALSE);
3556 return g_datalist_id_replace_data (&object->qdata,
3557 g_quark_from_string (key),
3558 oldval, newval, destroy,
3563 * g_object_set_data_full: (skip)
3564 * @object: #GObject containing the associations
3565 * @key: name of the key
3566 * @data: data to associate with that key
3567 * @destroy: function to call when the association is destroyed
3569 * Like g_object_set_data() except it adds notification
3570 * for when the association is destroyed, either by setting it
3571 * to a different value or when the object is destroyed.
3573 * Note that the @destroy callback is not called if @data is %NULL.
3576 g_object_set_data_full (GObject *object,
3579 GDestroyNotify destroy)
3581 g_return_if_fail (G_IS_OBJECT (object));
3582 g_return_if_fail (key != NULL);
3584 g_datalist_id_set_data_full (&object->qdata, g_quark_from_string (key), data,
3585 data ? destroy : (GDestroyNotify) NULL);
3589 * g_object_steal_data:
3590 * @object: #GObject containing the associations
3591 * @key: name of the key
3593 * Remove a specified datum from the object's data associations,
3594 * without invoking the association's destroy handler.
3596 * Returns: (transfer full): the data if found, or %NULL if no such data exists.
3599 g_object_steal_data (GObject *object,
3604 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3605 g_return_val_if_fail (key != NULL, NULL);
3607 quark = g_quark_try_string (key);
3609 return quark ? g_datalist_id_remove_no_notify (&object->qdata, quark) : NULL;
3613 g_value_object_init (GValue *value)
3615 value->data[0].v_pointer = NULL;
3619 g_value_object_free_value (GValue *value)
3621 if (value->data[0].v_pointer)
3622 g_object_unref (value->data[0].v_pointer);
3626 g_value_object_copy_value (const GValue *src_value,
3629 if (src_value->data[0].v_pointer)
3630 dest_value->data[0].v_pointer = g_object_ref (src_value->data[0].v_pointer);
3632 dest_value->data[0].v_pointer = NULL;
3636 g_value_object_transform_value (const GValue *src_value,
3639 if (src_value->data[0].v_pointer && g_type_is_a (G_OBJECT_TYPE (src_value->data[0].v_pointer), G_VALUE_TYPE (dest_value)))
3640 dest_value->data[0].v_pointer = g_object_ref (src_value->data[0].v_pointer);
3642 dest_value->data[0].v_pointer = NULL;
3646 g_value_object_peek_pointer (const GValue *value)
3648 return value->data[0].v_pointer;
3652 g_value_object_collect_value (GValue *value,
3653 guint n_collect_values,
3654 GTypeCValue *collect_values,
3655 guint collect_flags)
3657 if (collect_values[0].v_pointer)
3659 GObject *object = collect_values[0].v_pointer;
3661 if (object->g_type_instance.g_class == NULL)
3662 return g_strconcat ("invalid unclassed object pointer for value type `",
3663 G_VALUE_TYPE_NAME (value),
3666 else if (!g_value_type_compatible (G_OBJECT_TYPE (object), G_VALUE_TYPE (value)))
3667 return g_strconcat ("invalid object type `",
3668 G_OBJECT_TYPE_NAME (object),
3669 "' for value type `",
3670 G_VALUE_TYPE_NAME (value),
3673 /* never honour G_VALUE_NOCOPY_CONTENTS for ref-counted types */
3674 value->data[0].v_pointer = g_object_ref (object);
3677 value->data[0].v_pointer = NULL;
3683 g_value_object_lcopy_value (const GValue *value,
3684 guint n_collect_values,
3685 GTypeCValue *collect_values,
3686 guint collect_flags)
3688 GObject **object_p = collect_values[0].v_pointer;
3691 return g_strdup_printf ("value location for `%s' passed as NULL", G_VALUE_TYPE_NAME (value));
3693 if (!value->data[0].v_pointer)
3695 else if (collect_flags & G_VALUE_NOCOPY_CONTENTS)
3696 *object_p = value->data[0].v_pointer;
3698 *object_p = g_object_ref (value->data[0].v_pointer);
3704 * g_value_set_object:
3705 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
3706 * @v_object: (type GObject.Object) (allow-none): object value to be set
3708 * Set the contents of a %G_TYPE_OBJECT derived #GValue to @v_object.
3710 * g_value_set_object() increases the reference count of @v_object
3711 * (the #GValue holds a reference to @v_object). If you do not wish
3712 * to increase the reference count of the object (i.e. you wish to
3713 * pass your current reference to the #GValue because you no longer
3714 * need it), use g_value_take_object() instead.
3716 * It is important that your #GValue holds a reference to @v_object (either its
3717 * own, or one it has taken) to ensure that the object won't be destroyed while
3718 * the #GValue still exists).
3721 g_value_set_object (GValue *value,
3726 g_return_if_fail (G_VALUE_HOLDS_OBJECT (value));
3728 old = value->data[0].v_pointer;
3732 g_return_if_fail (G_IS_OBJECT (v_object));
3733 g_return_if_fail (g_value_type_compatible (G_OBJECT_TYPE (v_object), G_VALUE_TYPE (value)));
3735 value->data[0].v_pointer = v_object;
3736 g_object_ref (value->data[0].v_pointer);
3739 value->data[0].v_pointer = NULL;
3742 g_object_unref (old);
3746 * g_value_set_object_take_ownership: (skip)
3747 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
3748 * @v_object: (allow-none): object value to be set
3750 * This is an internal function introduced mainly for C marshallers.
3752 * Deprecated: 2.4: Use g_value_take_object() instead.
3755 g_value_set_object_take_ownership (GValue *value,
3758 g_value_take_object (value, v_object);
3762 * g_value_take_object: (skip)
3763 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
3764 * @v_object: (allow-none): object value to be set
3766 * Sets the contents of a %G_TYPE_OBJECT derived #GValue to @v_object
3767 * and takes over the ownership of the callers reference to @v_object;
3768 * the caller doesn't have to unref it any more (i.e. the reference
3769 * count of the object is not increased).
3771 * If you want the #GValue to hold its own reference to @v_object, use
3772 * g_value_set_object() instead.
3777 g_value_take_object (GValue *value,
3780 g_return_if_fail (G_VALUE_HOLDS_OBJECT (value));
3782 if (value->data[0].v_pointer)
3784 g_object_unref (value->data[0].v_pointer);
3785 value->data[0].v_pointer = NULL;
3790 g_return_if_fail (G_IS_OBJECT (v_object));
3791 g_return_if_fail (g_value_type_compatible (G_OBJECT_TYPE (v_object), G_VALUE_TYPE (value)));
3793 value->data[0].v_pointer = v_object; /* we take over the reference count */
3798 * g_value_get_object:
3799 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
3801 * Get the contents of a %G_TYPE_OBJECT derived #GValue.
3803 * Returns: (type GObject.Object) (transfer none): object contents of @value
3806 g_value_get_object (const GValue *value)
3808 g_return_val_if_fail (G_VALUE_HOLDS_OBJECT (value), NULL);
3810 return value->data[0].v_pointer;
3814 * g_value_dup_object:
3815 * @value: a valid #GValue whose type is derived from %G_TYPE_OBJECT
3817 * Get the contents of a %G_TYPE_OBJECT derived #GValue, increasing
3818 * its reference count. If the contents of the #GValue are %NULL, then
3819 * %NULL will be returned.
3821 * Returns: (type GObject.Object) (transfer full): object content of @value,
3822 * should be unreferenced when no longer needed.
3825 g_value_dup_object (const GValue *value)
3827 g_return_val_if_fail (G_VALUE_HOLDS_OBJECT (value), NULL);
3829 return value->data[0].v_pointer ? g_object_ref (value->data[0].v_pointer) : NULL;
3833 * g_signal_connect_object: (skip)
3834 * @instance: the instance to connect to.
3835 * @detailed_signal: a string of the form "signal-name::detail".
3836 * @c_handler: the #GCallback to connect.
3837 * @gobject: the object to pass as data to @c_handler.
3838 * @connect_flags: a combination of #GConnectFlags.
3840 * This is similar to g_signal_connect_data(), but uses a closure which
3841 * ensures that the @gobject stays alive during the call to @c_handler
3842 * by temporarily adding a reference count to @gobject.
3844 * When the @gobject is destroyed the signal handler will be automatically
3845 * disconnected. Note that this is not currently threadsafe (ie:
3846 * emitting a signal while @gobject is being destroyed in another thread
3849 * Returns: the handler id.
3852 g_signal_connect_object (gpointer instance,
3853 const gchar *detailed_signal,
3854 GCallback c_handler,
3856 GConnectFlags connect_flags)
3858 g_return_val_if_fail (G_TYPE_CHECK_INSTANCE (instance), 0);
3859 g_return_val_if_fail (detailed_signal != NULL, 0);
3860 g_return_val_if_fail (c_handler != NULL, 0);
3866 g_return_val_if_fail (G_IS_OBJECT (gobject), 0);
3868 closure = ((connect_flags & G_CONNECT_SWAPPED) ? g_cclosure_new_object_swap : g_cclosure_new_object) (c_handler, gobject);
3870 return g_signal_connect_closure (instance, detailed_signal, closure, connect_flags & G_CONNECT_AFTER);
3873 return g_signal_connect_data (instance, detailed_signal, c_handler, NULL, NULL, connect_flags);
3879 GClosure *closures[1]; /* flexible array */
3881 /* don't change this structure without supplying an accessor for
3882 * watched closures, e.g.:
3883 * GSList* g_object_list_watched_closures (GObject *object)
3886 * g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3887 * carray = g_object_get_data (object, "GObject-closure-array");
3890 * GSList *slist = NULL;
3892 * for (i = 0; i < carray->n_closures; i++)
3893 * slist = g_slist_prepend (slist, carray->closures[i]);
3901 object_remove_closure (gpointer data,
3904 GObject *object = data;
3908 G_LOCK (closure_array_mutex);
3909 carray = g_object_get_qdata (object, quark_closure_array);
3910 for (i = 0; i < carray->n_closures; i++)
3911 if (carray->closures[i] == closure)
3913 carray->n_closures--;
3914 if (i < carray->n_closures)
3915 carray->closures[i] = carray->closures[carray->n_closures];
3916 G_UNLOCK (closure_array_mutex);
3919 G_UNLOCK (closure_array_mutex);
3920 g_assert_not_reached ();
3924 destroy_closure_array (gpointer data)
3926 CArray *carray = data;
3927 GObject *object = carray->object;
3928 guint i, n = carray->n_closures;
3930 for (i = 0; i < n; i++)
3932 GClosure *closure = carray->closures[i];
3934 /* removing object_remove_closure() upfront is probably faster than
3935 * letting it fiddle with quark_closure_array which is empty anyways
3937 g_closure_remove_invalidate_notifier (closure, object, object_remove_closure);
3938 g_closure_invalidate (closure);
3944 * g_object_watch_closure:
3945 * @object: GObject restricting lifetime of @closure
3946 * @closure: GClosure to watch
3948 * This function essentially limits the life time of the @closure to
3949 * the life time of the object. That is, when the object is finalized,
3950 * the @closure is invalidated by calling g_closure_invalidate() on
3951 * it, in order to prevent invocations of the closure with a finalized
3952 * (nonexisting) object. Also, g_object_ref() and g_object_unref() are
3953 * added as marshal guards to the @closure, to ensure that an extra
3954 * reference count is held on @object during invocation of the
3955 * @closure. Usually, this function will be called on closures that
3956 * use this @object as closure data.
3959 g_object_watch_closure (GObject *object,
3965 g_return_if_fail (G_IS_OBJECT (object));
3966 g_return_if_fail (closure != NULL);
3967 g_return_if_fail (closure->is_invalid == FALSE);
3968 g_return_if_fail (closure->in_marshal == FALSE);
3969 g_return_if_fail (object->ref_count > 0); /* this doesn't work on finalizing objects */
3971 g_closure_add_invalidate_notifier (closure, object, object_remove_closure);
3972 g_closure_add_marshal_guards (closure,
3973 object, (GClosureNotify) g_object_ref,
3974 object, (GClosureNotify) g_object_unref);
3975 G_LOCK (closure_array_mutex);
3976 carray = g_datalist_id_remove_no_notify (&object->qdata, quark_closure_array);
3979 carray = g_renew (CArray, NULL, 1);
3980 carray->object = object;
3981 carray->n_closures = 1;
3986 i = carray->n_closures++;
3987 carray = g_realloc (carray, sizeof (*carray) + sizeof (carray->closures[0]) * i);
3989 carray->closures[i] = closure;
3990 g_datalist_id_set_data_full (&object->qdata, quark_closure_array, carray, destroy_closure_array);
3991 G_UNLOCK (closure_array_mutex);
3995 * g_closure_new_object:
3996 * @sizeof_closure: the size of the structure to allocate, must be at least
3997 * <literal>sizeof (GClosure)</literal>
3998 * @object: a #GObject pointer to store in the @data field of the newly
3999 * allocated #GClosure
4001 * A variant of g_closure_new_simple() which stores @object in the
4002 * @data field of the closure and calls g_object_watch_closure() on
4003 * @object and the created closure. This function is mainly useful
4004 * when implementing new types of closures.
4006 * Returns: (transfer full): a newly allocated #GClosure
4009 g_closure_new_object (guint sizeof_closure,
4014 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
4015 g_return_val_if_fail (object->ref_count > 0, NULL); /* this doesn't work on finalizing objects */
4017 closure = g_closure_new_simple (sizeof_closure, object);
4018 g_object_watch_closure (object, closure);
4024 * g_cclosure_new_object: (skip)
4025 * @callback_func: the function to invoke
4026 * @object: a #GObject pointer to pass to @callback_func
4028 * A variant of g_cclosure_new() which uses @object as @user_data and
4029 * calls g_object_watch_closure() on @object and the created
4030 * closure. This function is useful when you have a callback closely
4031 * associated with a #GObject, and want the callback to no longer run
4032 * after the object is is freed.
4034 * Returns: a new #GCClosure
4037 g_cclosure_new_object (GCallback callback_func,
4042 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
4043 g_return_val_if_fail (object->ref_count > 0, NULL); /* this doesn't work on finalizing objects */
4044 g_return_val_if_fail (callback_func != NULL, NULL);
4046 closure = g_cclosure_new (callback_func, object, NULL);
4047 g_object_watch_closure (object, closure);
4053 * g_cclosure_new_object_swap: (skip)
4054 * @callback_func: the function to invoke
4055 * @object: a #GObject pointer to pass to @callback_func
4057 * A variant of g_cclosure_new_swap() which uses @object as @user_data
4058 * and calls g_object_watch_closure() on @object and the created
4059 * closure. This function is useful when you have a callback closely
4060 * associated with a #GObject, and want the callback to no longer run
4061 * after the object is is freed.
4063 * Returns: a new #GCClosure
4066 g_cclosure_new_object_swap (GCallback callback_func,
4071 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
4072 g_return_val_if_fail (object->ref_count > 0, NULL); /* this doesn't work on finalizing objects */
4073 g_return_val_if_fail (callback_func != NULL, NULL);
4075 closure = g_cclosure_new_swap (callback_func, object, NULL);
4076 g_object_watch_closure (object, closure);
4082 g_object_compat_control (gsize what,
4088 case 1: /* floating base type */
4089 return G_TYPE_INITIALLY_UNOWNED;
4090 case 2: /* FIXME: remove this once GLib/Gtk+ break ABI again */
4091 floating_flag_handler = (guint(*)(GObject*,gint)) data;
4093 case 3: /* FIXME: remove this once GLib/Gtk+ break ABI again */
4095 *pp = floating_flag_handler;
4102 G_DEFINE_TYPE (GInitiallyUnowned, g_initially_unowned, G_TYPE_OBJECT);
4105 g_initially_unowned_init (GInitiallyUnowned *object)
4107 g_object_force_floating (object);
4111 g_initially_unowned_class_init (GInitiallyUnownedClass *klass)
4118 * A structure containing a weak reference to a #GObject. It can either
4119 * be empty (i.e. point to %NULL), or point to an object for as long as
4120 * at least one "strong" reference to that object exists. Before the
4121 * object's #GObjectClass.dispose method is called, every #GWeakRef
4122 * associated with becomes empty (i.e. points to %NULL).
4124 * Like #GValue, #GWeakRef can be statically allocated, stack- or
4125 * heap-allocated, or embedded in larger structures.
4127 * Unlike g_object_weak_ref() and g_object_add_weak_pointer(), this weak
4128 * reference is thread-safe: converting a weak pointer to a reference is
4129 * atomic with respect to invalidation of weak pointers to destroyed
4132 * If the object's #GObjectClass.dispose method results in additional
4133 * references to the object being held, any #GWeakRef<!-- -->s taken
4134 * before it was disposed will continue to point to %NULL. If
4135 * #GWeakRef<!-- -->s are taken after the object is disposed and
4136 * re-referenced, they will continue to point to it until its refcount
4137 * goes back to zero, at which point they too will be invalidated.
4141 * g_weak_ref_init: (skip)
4142 * @weak_ref: (inout): uninitialized or empty location for a weak
4144 * @object: (allow-none): a #GObject or %NULL
4146 * Initialise a non-statically-allocated #GWeakRef.
4148 * This function also calls g_weak_ref_set() with @object on the
4149 * freshly-initialised weak reference.
4151 * This function should always be matched with a call to
4152 * g_weak_ref_clear(). It is not necessary to use this function for a
4153 * #GWeakRef in static storage because it will already be
4154 * properly initialised. Just use g_weak_ref_set() directly.
4159 g_weak_ref_init (GWeakRef *weak_ref,
4162 weak_ref->priv.p = NULL;
4164 g_weak_ref_set (weak_ref, object);
4168 * g_weak_ref_clear: (skip)
4169 * @weak_ref: (inout): location of a weak reference, which
4172 * Frees resources associated with a non-statically-allocated #GWeakRef.
4173 * After this call, the #GWeakRef is left in an undefined state.
4175 * You should only call this on a #GWeakRef that previously had
4176 * g_weak_ref_init() called on it.
4181 g_weak_ref_clear (GWeakRef *weak_ref)
4183 g_weak_ref_set (weak_ref, NULL);
4186 weak_ref->priv.p = (void *) 0xccccccccu;
4190 * g_weak_ref_get: (skip)
4191 * @weak_ref: (inout): location of a weak reference to a #GObject
4193 * If @weak_ref is not empty, atomically acquire a strong
4194 * reference to the object it points to, and return that reference.
4196 * This function is needed because of the potential race between taking
4197 * the pointer value and g_object_ref() on it, if the object was losing
4198 * its last reference at the same time in a different thread.
4200 * The caller should release the resulting reference in the usual way,
4201 * by using g_object_unref().
4203 * Returns: (transfer full) (type GObject.Object): the object pointed to
4204 * by @weak_ref, or %NULL if it was empty
4209 g_weak_ref_get (GWeakRef *weak_ref)
4211 gpointer object_or_null;
4213 g_return_val_if_fail (weak_ref!= NULL, NULL);
4215 g_rw_lock_reader_lock (&weak_locations_lock);
4217 object_or_null = weak_ref->priv.p;
4219 if (object_or_null != NULL)
4220 g_object_ref (object_or_null);
4222 g_rw_lock_reader_unlock (&weak_locations_lock);
4224 return object_or_null;
4228 * g_weak_ref_set: (skip)
4229 * @weak_ref: location for a weak reference
4230 * @object: (allow-none): a #GObject or %NULL
4232 * Change the object to which @weak_ref points, or set it to
4235 * You must own a strong reference on @object while calling this
4241 g_weak_ref_set (GWeakRef *weak_ref,
4244 GSList **weak_locations;
4245 GObject *new_object;
4246 GObject *old_object;
4248 g_return_if_fail (weak_ref != NULL);
4249 g_return_if_fail (object == NULL || G_IS_OBJECT (object));
4251 new_object = object;
4253 g_rw_lock_writer_lock (&weak_locations_lock);
4255 /* We use the extra level of indirection here so that if we have ever
4256 * had a weak pointer installed at any point in time on this object,
4257 * we can see that there is a non-NULL value associated with the
4258 * weak-pointer quark and know that this value will not change at any
4259 * point in the object's lifetime.
4261 * Both properties are important for reducing the amount of times we
4262 * need to acquire locks and for decreasing the duration of time the
4263 * lock is held while avoiding some rather tricky races.
4265 * Specifically: we can avoid having to do an extra unconditional lock
4266 * in g_object_unref() without worrying about some extremely tricky
4270 old_object = weak_ref->priv.p;
4271 if (new_object != old_object)
4273 weak_ref->priv.p = new_object;
4275 /* Remove the weak ref from the old object */
4276 if (old_object != NULL)
4278 weak_locations = g_datalist_id_get_data (&old_object->qdata, quark_weak_locations);
4279 /* for it to point to an object, the object must have had it added once */
4280 g_assert (weak_locations != NULL);
4282 *weak_locations = g_slist_remove (*weak_locations, weak_ref);
4285 /* Add the weak ref to the new object */
4286 if (new_object != NULL)
4288 weak_locations = g_datalist_id_get_data (&new_object->qdata, quark_weak_locations);
4290 if (weak_locations == NULL)
4292 weak_locations = g_new0 (GSList *, 1);
4293 g_datalist_id_set_data_full (&new_object->qdata, quark_weak_locations, weak_locations, g_free);
4296 *weak_locations = g_slist_prepend (*weak_locations, weak_ref);
4300 g_rw_lock_writer_unlock (&weak_locations_lock);