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 check_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 GQuark quark_in_construction;
201 static GParamSpecPool *pspec_pool = NULL;
202 static gulong gobject_signals[LAST_SIGNAL] = { 0, };
203 static guint (*floating_flag_handler) (GObject*, gint) = object_floating_flag_handler;
204 /* qdata pointing to GSList<GWeakRef *>, protected by weak_locations_lock */
205 static GQuark quark_weak_locations = 0;
206 static GRWLock weak_locations_lock;
208 G_LOCK_DEFINE_STATIC(notify_lock);
210 /* --- functions --- */
212 g_object_notify_queue_free (gpointer data)
214 GObjectNotifyQueue *nqueue = data;
216 g_slist_free (nqueue->pspecs);
217 g_slice_free (GObjectNotifyQueue, nqueue);
220 static GObjectNotifyQueue*
221 g_object_notify_queue_freeze (GObject *object,
222 gboolean conditional)
224 GObjectNotifyQueue *nqueue;
227 nqueue = g_datalist_id_get_data (&object->qdata, quark_notify_queue);
232 G_UNLOCK(notify_lock);
236 nqueue = g_slice_new0 (GObjectNotifyQueue);
237 g_datalist_id_set_data_full (&object->qdata, quark_notify_queue,
238 nqueue, g_object_notify_queue_free);
241 if (nqueue->freeze_count >= 65535)
242 g_critical("Free queue for %s (%p) is larger than 65535,"
243 " called g_object_freeze_notify() too often."
244 " Forgot to call g_object_thaw_notify() or infinite loop",
245 G_OBJECT_TYPE_NAME (object), object);
247 nqueue->freeze_count++;
248 G_UNLOCK(notify_lock);
254 g_object_notify_queue_thaw (GObject *object,
255 GObjectNotifyQueue *nqueue)
257 GParamSpec *pspecs_mem[16], **pspecs, **free_me = NULL;
261 g_return_if_fail (nqueue->freeze_count > 0);
262 g_return_if_fail (g_atomic_int_get(&object->ref_count) > 0);
266 /* Just make sure we never get into some nasty race condition */
267 if (G_UNLIKELY(nqueue->freeze_count == 0)) {
268 G_UNLOCK(notify_lock);
269 g_warning ("%s: property-changed notification for %s(%p) is not frozen",
270 G_STRFUNC, G_OBJECT_TYPE_NAME (object), object);
274 nqueue->freeze_count--;
275 if (nqueue->freeze_count) {
276 G_UNLOCK(notify_lock);
280 pspecs = nqueue->n_pspecs > 16 ? free_me = g_new (GParamSpec*, nqueue->n_pspecs) : pspecs_mem;
282 for (slist = nqueue->pspecs; slist; slist = slist->next)
284 pspecs[n_pspecs++] = slist->data;
286 g_datalist_id_set_data (&object->qdata, quark_notify_queue, NULL);
288 G_UNLOCK(notify_lock);
291 G_OBJECT_GET_CLASS (object)->dispatch_properties_changed (object, n_pspecs, pspecs);
296 g_object_notify_queue_add (GObject *object,
297 GObjectNotifyQueue *nqueue,
302 g_return_if_fail (nqueue->n_pspecs < 65535);
304 if (g_slist_find (nqueue->pspecs, pspec) == NULL)
306 nqueue->pspecs = g_slist_prepend (nqueue->pspecs, pspec);
310 G_UNLOCK(notify_lock);
313 #ifdef G_ENABLE_DEBUG
314 #define IF_DEBUG(debug_type) if (_g_type_debug_flags & G_TYPE_DEBUG_ ## debug_type)
315 G_LOCK_DEFINE_STATIC (debug_objects);
316 static volatile GObject *g_trap_object_ref = NULL;
317 static guint debug_objects_count = 0;
318 static GHashTable *debug_objects_ht = NULL;
321 debug_objects_foreach (gpointer key,
325 GObject *object = value;
327 g_message ("[%p] stale %s\tref_count=%u",
329 G_OBJECT_TYPE_NAME (object),
333 #ifdef G_HAS_CONSTRUCTORS
334 #ifdef G_DEFINE_DESTRUCTOR_NEEDS_PRAGMA
335 #pragma G_DEFINE_DESTRUCTOR_PRAGMA_ARGS(debug_objects_atexit)
337 G_DEFINE_DESTRUCTOR(debug_objects_atexit)
338 #endif /* G_HAS_CONSTRUCTORS */
341 debug_objects_atexit (void)
345 G_LOCK (debug_objects);
346 g_message ("stale GObjects: %u", debug_objects_count);
347 g_hash_table_foreach (debug_objects_ht, debug_objects_foreach, NULL);
348 G_UNLOCK (debug_objects);
351 #endif /* G_ENABLE_DEBUG */
354 _g_object_type_init (void)
356 static gboolean initialized = FALSE;
357 static const GTypeFundamentalInfo finfo = {
358 G_TYPE_FLAG_CLASSED | G_TYPE_FLAG_INSTANTIATABLE | G_TYPE_FLAG_DERIVABLE | G_TYPE_FLAG_DEEP_DERIVABLE,
361 sizeof (GObjectClass),
362 (GBaseInitFunc) g_object_base_class_init,
363 (GBaseFinalizeFunc) g_object_base_class_finalize,
364 (GClassInitFunc) g_object_do_class_init,
365 NULL /* class_destroy */,
366 NULL /* class_data */,
369 (GInstanceInitFunc) g_object_init,
370 NULL, /* value_table */
372 static const GTypeValueTable value_table = {
373 g_value_object_init, /* value_init */
374 g_value_object_free_value, /* value_free */
375 g_value_object_copy_value, /* value_copy */
376 g_value_object_peek_pointer, /* value_peek_pointer */
377 "p", /* collect_format */
378 g_value_object_collect_value, /* collect_value */
379 "p", /* lcopy_format */
380 g_value_object_lcopy_value, /* lcopy_value */
384 g_return_if_fail (initialized == FALSE);
389 info.value_table = &value_table;
390 type = g_type_register_fundamental (G_TYPE_OBJECT, g_intern_static_string ("GObject"), &info, &finfo, 0);
391 g_assert (type == G_TYPE_OBJECT);
392 g_value_register_transform_func (G_TYPE_OBJECT, G_TYPE_OBJECT, g_value_object_transform_value);
394 #ifdef G_ENABLE_DEBUG
397 debug_objects_ht = g_hash_table_new (g_direct_hash, NULL);
398 #ifndef G_HAS_CONSTRUCTORS
399 g_atexit (debug_objects_atexit);
400 #endif /* G_HAS_CONSTRUCTORS */
402 #endif /* G_ENABLE_DEBUG */
406 g_object_base_class_init (GObjectClass *class)
408 GObjectClass *pclass = g_type_class_peek_parent (class);
410 /* Don't inherit HAS_DERIVED_CLASS flag from parent class */
411 class->flags &= ~CLASS_HAS_DERIVED_CLASS_FLAG;
414 pclass->flags |= CLASS_HAS_DERIVED_CLASS_FLAG;
416 /* reset instance specific fields and methods that don't get inherited */
417 class->construct_properties = pclass ? g_slist_copy (pclass->construct_properties) : NULL;
418 class->get_property = NULL;
419 class->set_property = NULL;
423 g_object_base_class_finalize (GObjectClass *class)
427 _g_signals_destroy (G_OBJECT_CLASS_TYPE (class));
429 g_slist_free (class->construct_properties);
430 class->construct_properties = NULL;
431 list = g_param_spec_pool_list_owned (pspec_pool, G_OBJECT_CLASS_TYPE (class));
432 for (node = list; node; node = node->next)
434 GParamSpec *pspec = node->data;
436 g_param_spec_pool_remove (pspec_pool, pspec);
437 PARAM_SPEC_SET_PARAM_ID (pspec, 0);
438 g_param_spec_unref (pspec);
444 g_object_do_class_init (GObjectClass *class)
446 /* read the comment about typedef struct CArray; on why not to change this quark */
447 quark_closure_array = g_quark_from_static_string ("GObject-closure-array");
449 quark_weak_refs = g_quark_from_static_string ("GObject-weak-references");
450 quark_weak_locations = g_quark_from_static_string ("GObject-weak-locations");
451 quark_toggle_refs = g_quark_from_static_string ("GObject-toggle-references");
452 quark_notify_queue = g_quark_from_static_string ("GObject-notify-queue");
453 quark_in_construction = g_quark_from_static_string ("GObject-in-construction");
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", G_OBJECT_CLASS_NAME (class), pspec->name);
545 if (!g_type_is_in_init (G_OBJECT_CLASS_TYPE (class)))
546 g_warning ("Attempt to add property %s::%s after class was initialised", G_OBJECT_CLASS_NAME (class), pspec->name);
548 class->flags |= CLASS_HAS_PROPS_FLAG;
550 g_return_if_fail (pspec->flags & (G_PARAM_READABLE | G_PARAM_WRITABLE));
551 if (pspec->flags & G_PARAM_WRITABLE)
552 g_return_if_fail (class->set_property != NULL);
553 if (pspec->flags & G_PARAM_READABLE)
554 g_return_if_fail (class->get_property != NULL);
555 g_return_if_fail (property_id > 0);
556 g_return_if_fail (PARAM_SPEC_PARAM_ID (pspec) == 0); /* paranoid */
557 if (pspec->flags & G_PARAM_CONSTRUCT)
558 g_return_if_fail ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) == 0);
559 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
560 g_return_if_fail (pspec->flags & G_PARAM_WRITABLE);
562 install_property_internal (G_OBJECT_CLASS_TYPE (class), property_id, pspec);
564 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
565 class->construct_properties = g_slist_append (class->construct_properties, pspec);
567 /* for property overrides of construct properties, we have to get rid
568 * of the overidden inherited construct property
570 pspec = g_param_spec_pool_lookup (pspec_pool, pspec->name, g_type_parent (G_OBJECT_CLASS_TYPE (class)), TRUE);
571 if (pspec && pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
572 class->construct_properties = g_slist_remove (class->construct_properties, pspec);
576 * g_object_class_install_properties:
577 * @oclass: a #GObjectClass
578 * @n_pspecs: the length of the #GParamSpec<!-- -->s array
579 * @pspecs: (array length=n_pspecs): the #GParamSpec<!-- -->s array
580 * defining the new properties
582 * Installs new properties from an array of #GParamSpec<!-- -->s. This is
583 * usually done in the class initializer.
585 * The property id of each property is the index of each #GParamSpec in
588 * The property id of 0 is treated specially by #GObject and it should not
589 * be used to store a #GParamSpec.
591 * This function should be used if you plan to use a static array of
592 * #GParamSpec<!-- -->s and g_object_notify_by_pspec(). For instance, this
593 * class initialization:
597 * PROP_0, PROP_FOO, PROP_BAR, N_PROPERTIES
600 * static GParamSpec *obj_properties[N_PROPERTIES] = { NULL, };
603 * my_object_class_init (MyObjectClass *klass)
605 * GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
607 * obj_properties[PROP_FOO] =
608 * g_param_spec_int ("foo", "Foo", "Foo",
611 * G_PARAM_READWRITE);
613 * obj_properties[PROP_BAR] =
614 * g_param_spec_string ("bar", "Bar", "Bar",
616 * G_PARAM_READWRITE);
618 * gobject_class->set_property = my_object_set_property;
619 * gobject_class->get_property = my_object_get_property;
620 * g_object_class_install_properties (gobject_class,
626 * allows calling g_object_notify_by_pspec() to notify of property changes:
630 * my_object_set_foo (MyObject *self, gint foo)
632 * if (self->foo != foo)
635 * g_object_notify_by_pspec (G_OBJECT (self), obj_properties[PROP_FOO]);
643 g_object_class_install_properties (GObjectClass *oclass,
647 GType oclass_type, parent_type;
650 g_return_if_fail (G_IS_OBJECT_CLASS (oclass));
651 g_return_if_fail (n_pspecs > 1);
652 g_return_if_fail (pspecs[0] == NULL);
654 if (CLASS_HAS_DERIVED_CLASS (oclass))
655 g_error ("Attempt to add properties to %s after it was derived",
656 G_OBJECT_CLASS_NAME (oclass));
658 if (!g_type_is_in_init (G_OBJECT_CLASS_TYPE (oclass)))
659 g_warning ("Attempt to add properties to %s after it was initialised", G_OBJECT_CLASS_NAME (oclass));
661 oclass_type = G_OBJECT_CLASS_TYPE (oclass);
662 parent_type = g_type_parent (oclass_type);
664 /* we skip the first element of the array as it would have a 0 prop_id */
665 for (i = 1; i < n_pspecs; i++)
667 GParamSpec *pspec = pspecs[i];
669 g_return_if_fail (pspec != NULL);
671 if (pspec->flags & G_PARAM_WRITABLE)
672 g_return_if_fail (oclass->set_property != NULL);
673 if (pspec->flags & G_PARAM_READABLE)
674 g_return_if_fail (oclass->get_property != NULL);
675 g_return_if_fail (PARAM_SPEC_PARAM_ID (pspec) == 0); /* paranoid */
676 if (pspec->flags & G_PARAM_CONSTRUCT)
677 g_return_if_fail ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) == 0);
678 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
679 g_return_if_fail (pspec->flags & G_PARAM_WRITABLE);
681 oclass->flags |= CLASS_HAS_PROPS_FLAG;
682 install_property_internal (oclass_type, i, pspec);
684 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
685 oclass->construct_properties = g_slist_append (oclass->construct_properties, pspec);
687 /* for property overrides of construct properties, we have to get rid
688 * of the overidden inherited construct property
690 pspec = g_param_spec_pool_lookup (pspec_pool, pspec->name, parent_type, TRUE);
691 if (pspec && pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
692 oclass->construct_properties = g_slist_remove (oclass->construct_properties, pspec);
697 * g_object_interface_install_property:
698 * @g_iface: any interface vtable for the interface, or the default
699 * vtable for the interface.
700 * @pspec: the #GParamSpec for the new property
702 * Add a property to an interface; this is only useful for interfaces
703 * that are added to GObject-derived types. Adding a property to an
704 * interface forces all objects classes with that interface to have a
705 * compatible property. The compatible property could be a newly
706 * created #GParamSpec, but normally
707 * g_object_class_override_property() will be used so that the object
708 * class only needs to provide an implementation and inherits the
709 * property description, default value, bounds, and so forth from the
710 * interface property.
712 * This function is meant to be called from the interface's default
713 * vtable initialization function (the @class_init member of
714 * #GTypeInfo.) It must not be called after after @class_init has
715 * been called for any object types implementing this interface.
720 g_object_interface_install_property (gpointer g_iface,
723 GTypeInterface *iface_class = g_iface;
725 g_return_if_fail (G_TYPE_IS_INTERFACE (iface_class->g_type));
726 g_return_if_fail (G_IS_PARAM_SPEC (pspec));
727 g_return_if_fail (!G_IS_PARAM_SPEC_OVERRIDE (pspec)); /* paranoid */
728 g_return_if_fail (PARAM_SPEC_PARAM_ID (pspec) == 0); /* paranoid */
730 g_return_if_fail (pspec->flags & (G_PARAM_READABLE | G_PARAM_WRITABLE));
731 if (pspec->flags & G_PARAM_CONSTRUCT)
732 g_return_if_fail ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) == 0);
733 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
734 g_return_if_fail (pspec->flags & G_PARAM_WRITABLE);
736 install_property_internal (iface_class->g_type, 0, pspec);
740 * g_object_class_find_property:
741 * @oclass: a #GObjectClass
742 * @property_name: the name of the property to look up
744 * Looks up the #GParamSpec for a property of a class.
746 * Returns: (transfer none): the #GParamSpec for the property, or
747 * %NULL if the class doesn't have a property of that name
750 g_object_class_find_property (GObjectClass *class,
751 const gchar *property_name)
754 GParamSpec *redirect;
756 g_return_val_if_fail (G_IS_OBJECT_CLASS (class), NULL);
757 g_return_val_if_fail (property_name != NULL, NULL);
759 pspec = g_param_spec_pool_lookup (pspec_pool,
761 G_OBJECT_CLASS_TYPE (class),
765 redirect = g_param_spec_get_redirect_target (pspec);
776 * g_object_interface_find_property:
777 * @g_iface: any interface vtable for the interface, or the default
778 * vtable for the interface
779 * @property_name: name of a property to lookup.
781 * Find the #GParamSpec with the given name for an
782 * interface. Generally, the interface vtable passed in as @g_iface
783 * will be the default vtable from g_type_default_interface_ref(), or,
784 * if you know the interface has already been loaded,
785 * g_type_default_interface_peek().
789 * Returns: (transfer none): the #GParamSpec for the property of the
790 * interface with the name @property_name, or %NULL if no
791 * such property exists.
794 g_object_interface_find_property (gpointer g_iface,
795 const gchar *property_name)
797 GTypeInterface *iface_class = g_iface;
799 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface_class->g_type), NULL);
800 g_return_val_if_fail (property_name != NULL, NULL);
802 return g_param_spec_pool_lookup (pspec_pool,
809 * g_object_class_override_property:
810 * @oclass: a #GObjectClass
811 * @property_id: the new property ID
812 * @name: the name of a property registered in a parent class or
813 * in an interface of this class.
815 * Registers @property_id as referring to a property with the
816 * name @name in a parent class or in an interface implemented
817 * by @oclass. This allows this class to <firstterm>override</firstterm>
818 * a property implementation in a parent class or to provide
819 * the implementation of a property from an interface.
822 * Internally, overriding is implemented by creating a property of type
823 * #GParamSpecOverride; generally operations that query the properties of
824 * the object class, such as g_object_class_find_property() or
825 * g_object_class_list_properties() will return the overridden
826 * property. However, in one case, the @construct_properties argument of
827 * the @constructor virtual function, the #GParamSpecOverride is passed
828 * instead, so that the @param_id field of the #GParamSpec will be
829 * correct. For virtually all uses, this makes no difference. If you
830 * need to get the overridden property, you can call
831 * g_param_spec_get_redirect_target().
837 g_object_class_override_property (GObjectClass *oclass,
841 GParamSpec *overridden = NULL;
845 g_return_if_fail (G_IS_OBJECT_CLASS (oclass));
846 g_return_if_fail (property_id > 0);
847 g_return_if_fail (name != NULL);
849 /* Find the overridden property; first check parent types
851 parent_type = g_type_parent (G_OBJECT_CLASS_TYPE (oclass));
852 if (parent_type != G_TYPE_NONE)
853 overridden = g_param_spec_pool_lookup (pspec_pool,
862 /* Now check interfaces
864 ifaces = g_type_interfaces (G_OBJECT_CLASS_TYPE (oclass), &n_ifaces);
865 while (n_ifaces-- && !overridden)
867 overridden = g_param_spec_pool_lookup (pspec_pool,
878 g_warning ("%s: Can't find property to override for '%s::%s'",
879 G_STRFUNC, G_OBJECT_CLASS_NAME (oclass), name);
883 new = g_param_spec_override (name, overridden);
884 g_object_class_install_property (oclass, property_id, new);
888 * g_object_class_list_properties:
889 * @oclass: a #GObjectClass
890 * @n_properties: (out): return location for the length of the returned array
892 * Get an array of #GParamSpec* for all properties of a class.
894 * Returns: (array length=n_properties) (transfer container): an array of
895 * #GParamSpec* which should be freed after use
897 GParamSpec** /* free result */
898 g_object_class_list_properties (GObjectClass *class,
899 guint *n_properties_p)
904 g_return_val_if_fail (G_IS_OBJECT_CLASS (class), NULL);
906 pspecs = g_param_spec_pool_list (pspec_pool,
907 G_OBJECT_CLASS_TYPE (class),
916 * g_object_interface_list_properties:
917 * @g_iface: any interface vtable for the interface, or the default
918 * vtable for the interface
919 * @n_properties_p: (out): location to store number of properties returned.
921 * Lists the properties of an interface.Generally, the interface
922 * vtable passed in as @g_iface will be the default vtable from
923 * g_type_default_interface_ref(), or, if you know the interface has
924 * already been loaded, g_type_default_interface_peek().
928 * Returns: (array length=n_properties_p) (transfer container): a
929 * pointer to an array of pointers to #GParamSpec
930 * structures. The paramspecs are owned by GLib, but the
931 * array should be freed with g_free() when you are done with
935 g_object_interface_list_properties (gpointer g_iface,
936 guint *n_properties_p)
938 GTypeInterface *iface_class = g_iface;
942 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface_class->g_type), NULL);
944 pspecs = g_param_spec_pool_list (pspec_pool,
953 static inline gboolean
954 object_in_construction (GObject *object)
956 return g_datalist_id_get_data (&object->qdata, quark_in_construction) != NULL;
960 g_object_init (GObject *object,
963 object->ref_count = 1;
964 object->qdata = NULL;
966 if (CLASS_HAS_PROPS (class))
968 /* freeze object's notification queue, g_object_newv() preserves pairedness */
969 g_object_notify_queue_freeze (object, FALSE);
972 if (CLASS_HAS_CUSTOM_CONSTRUCTOR (class))
974 /* mark object in-construction for notify_queue_thaw() and to allow construct-only properties */
975 g_datalist_id_set_data (&object->qdata, quark_in_construction, object);
978 #ifdef G_ENABLE_DEBUG
981 G_LOCK (debug_objects);
982 debug_objects_count++;
983 g_hash_table_insert (debug_objects_ht, object, object);
984 G_UNLOCK (debug_objects);
986 #endif /* G_ENABLE_DEBUG */
990 g_object_do_set_property (GObject *object,
998 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
1004 g_object_do_get_property (GObject *object,
1009 switch (property_id)
1012 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
1018 g_object_real_dispose (GObject *object)
1020 g_signal_handlers_destroy (object);
1021 g_datalist_id_set_data (&object->qdata, quark_closure_array, NULL);
1022 g_datalist_id_set_data (&object->qdata, quark_weak_refs, NULL);
1026 g_object_finalize (GObject *object)
1028 if (object_in_construction (object))
1030 g_error ("object %s %p finalized while still in-construction",
1031 G_OBJECT_TYPE_NAME (object), object);
1034 g_datalist_clear (&object->qdata);
1036 #ifdef G_ENABLE_DEBUG
1039 G_LOCK (debug_objects);
1040 g_assert (g_hash_table_lookup (debug_objects_ht, object) == object);
1041 g_hash_table_remove (debug_objects_ht, object);
1042 debug_objects_count--;
1043 G_UNLOCK (debug_objects);
1045 #endif /* G_ENABLE_DEBUG */
1050 g_object_dispatch_properties_changed (GObject *object,
1052 GParamSpec **pspecs)
1056 for (i = 0; i < n_pspecs; i++)
1057 g_signal_emit (object, gobject_signals[NOTIFY], g_quark_from_string (pspecs[i]->name), pspecs[i]);
1061 * g_object_run_dispose:
1062 * @object: a #GObject
1064 * Releases all references to other objects. This can be used to break
1067 * This functions should only be called from object system implementations.
1070 g_object_run_dispose (GObject *object)
1072 g_return_if_fail (G_IS_OBJECT (object));
1073 g_return_if_fail (object->ref_count > 0);
1075 g_object_ref (object);
1076 TRACE (GOBJECT_OBJECT_DISPOSE(object,G_TYPE_FROM_INSTANCE(object), 0));
1077 G_OBJECT_GET_CLASS (object)->dispose (object);
1078 TRACE (GOBJECT_OBJECT_DISPOSE_END(object,G_TYPE_FROM_INSTANCE(object), 0));
1079 g_object_unref (object);
1083 * g_object_freeze_notify:
1084 * @object: a #GObject
1086 * Increases the freeze count on @object. If the freeze count is
1087 * non-zero, the emission of "notify" signals on @object is
1088 * stopped. The signals are queued until the freeze count is decreased
1089 * to zero. Duplicate notifications are squashed so that at most one
1090 * #GObject::notify signal is emitted for each property modified while the
1093 * This is necessary for accessors that modify multiple properties to prevent
1094 * premature notification while the object is still being modified.
1097 g_object_freeze_notify (GObject *object)
1099 g_return_if_fail (G_IS_OBJECT (object));
1101 if (g_atomic_int_get (&object->ref_count) == 0)
1104 g_object_ref (object);
1105 g_object_notify_queue_freeze (object, FALSE);
1106 g_object_unref (object);
1110 get_notify_pspec (GParamSpec *pspec)
1112 GParamSpec *redirected;
1114 /* we don't notify on non-READABLE parameters */
1115 if (~pspec->flags & G_PARAM_READABLE)
1118 /* if the paramspec is redirected, notify on the target */
1119 redirected = g_param_spec_get_redirect_target (pspec);
1120 if (redirected != NULL)
1123 /* else, notify normally */
1128 g_object_notify_by_spec_internal (GObject *object,
1131 GParamSpec *notify_pspec;
1133 notify_pspec = get_notify_pspec (pspec);
1135 if (notify_pspec != NULL)
1137 GObjectNotifyQueue *nqueue;
1139 /* conditional freeze: only increase freeze count if already frozen */
1140 nqueue = g_object_notify_queue_freeze (object, TRUE);
1144 /* we're frozen, so add to the queue and release our freeze */
1145 g_object_notify_queue_add (object, nqueue, notify_pspec);
1146 g_object_notify_queue_thaw (object, nqueue);
1149 /* not frozen, so just dispatch the notification directly */
1150 G_OBJECT_GET_CLASS (object)
1151 ->dispatch_properties_changed (object, 1, ¬ify_pspec);
1157 * @object: a #GObject
1158 * @property_name: the name of a property installed on the class of @object.
1160 * Emits a "notify" signal for the property @property_name on @object.
1162 * When possible, eg. when signaling a property change from within the class
1163 * that registered the property, you should use g_object_notify_by_pspec()
1166 * Note that emission of the notify signal may be blocked with
1167 * g_object_freeze_notify(). In this case, the signal emissions are queued
1168 * and will be emitted (in reverse order) when g_object_thaw_notify() is
1172 g_object_notify (GObject *object,
1173 const gchar *property_name)
1177 g_return_if_fail (G_IS_OBJECT (object));
1178 g_return_if_fail (property_name != NULL);
1179 if (g_atomic_int_get (&object->ref_count) == 0)
1182 g_object_ref (object);
1183 /* We don't need to get the redirect target
1184 * (by, e.g. calling g_object_class_find_property())
1185 * because g_object_notify_queue_add() does that
1187 pspec = g_param_spec_pool_lookup (pspec_pool,
1189 G_OBJECT_TYPE (object),
1193 g_warning ("%s: object class '%s' has no property named '%s'",
1195 G_OBJECT_TYPE_NAME (object),
1198 g_object_notify_by_spec_internal (object, pspec);
1199 g_object_unref (object);
1203 * g_object_notify_by_pspec:
1204 * @object: a #GObject
1205 * @pspec: the #GParamSpec of a property installed on the class of @object.
1207 * Emits a "notify" signal for the property specified by @pspec on @object.
1209 * This function omits the property name lookup, hence it is faster than
1210 * g_object_notify().
1212 * One way to avoid using g_object_notify() from within the
1213 * class that registered the properties, and using g_object_notify_by_pspec()
1214 * instead, is to store the GParamSpec used with
1215 * g_object_class_install_property() inside a static array, e.g.:
1225 * static GParamSpec *properties[PROP_LAST];
1228 * my_object_class_init (MyObjectClass *klass)
1230 * properties[PROP_FOO] = g_param_spec_int ("foo", "Foo", "The foo",
1233 * G_PARAM_READWRITE);
1234 * g_object_class_install_property (gobject_class,
1236 * properties[PROP_FOO]);
1240 * and then notify a change on the "foo" property with:
1243 * g_object_notify_by_pspec (self, properties[PROP_FOO]);
1249 g_object_notify_by_pspec (GObject *object,
1253 g_return_if_fail (G_IS_OBJECT (object));
1254 g_return_if_fail (G_IS_PARAM_SPEC (pspec));
1256 if (g_atomic_int_get (&object->ref_count) == 0)
1259 g_object_ref (object);
1260 g_object_notify_by_spec_internal (object, pspec);
1261 g_object_unref (object);
1265 * g_object_thaw_notify:
1266 * @object: a #GObject
1268 * Reverts the effect of a previous call to
1269 * g_object_freeze_notify(). The freeze count is decreased on @object
1270 * and when it reaches zero, queued "notify" signals are emitted.
1272 * Duplicate notifications for each property are squashed so that at most one
1273 * #GObject::notify signal is emitted for each property, in the reverse order
1274 * in which they have been queued.
1276 * It is an error to call this function when the freeze count is zero.
1279 g_object_thaw_notify (GObject *object)
1281 GObjectNotifyQueue *nqueue;
1283 g_return_if_fail (G_IS_OBJECT (object));
1284 if (g_atomic_int_get (&object->ref_count) == 0)
1287 g_object_ref (object);
1289 /* FIXME: Freezing is the only way to get at the notify queue.
1290 * So we freeze once and then thaw twice.
1292 nqueue = g_object_notify_queue_freeze (object, FALSE);
1293 g_object_notify_queue_thaw (object, nqueue);
1294 g_object_notify_queue_thaw (object, nqueue);
1296 g_object_unref (object);
1300 object_get_property (GObject *object,
1304 GObjectClass *class = g_type_class_peek (pspec->owner_type);
1305 guint param_id = PARAM_SPEC_PARAM_ID (pspec);
1306 GParamSpec *redirect;
1310 g_warning ("'%s::%s' is not a valid property name; '%s' is not a GObject subtype",
1311 g_type_name (pspec->owner_type), pspec->name, g_type_name (pspec->owner_type));
1315 redirect = g_param_spec_get_redirect_target (pspec);
1319 class->get_property (object, param_id, value, pspec);
1323 object_set_property (GObject *object,
1325 const GValue *value,
1326 GObjectNotifyQueue *nqueue)
1328 GValue tmp_value = G_VALUE_INIT;
1329 GObjectClass *class = g_type_class_peek (pspec->owner_type);
1330 guint param_id = PARAM_SPEC_PARAM_ID (pspec);
1331 GParamSpec *redirect;
1332 static const gchar * enable_diagnostic = NULL;
1336 g_warning ("'%s::%s' is not a valid property name; '%s' is not a GObject subtype",
1337 g_type_name (pspec->owner_type), pspec->name, g_type_name (pspec->owner_type));
1341 redirect = g_param_spec_get_redirect_target (pspec);
1345 if (G_UNLIKELY (!enable_diagnostic))
1347 enable_diagnostic = g_getenv ("G_ENABLE_DIAGNOSTIC");
1348 if (!enable_diagnostic)
1349 enable_diagnostic = "0";
1352 if (enable_diagnostic[0] == '1')
1354 if (pspec->flags & G_PARAM_DEPRECATED)
1355 g_warning ("The property %s:%s is deprecated and shouldn't be used "
1356 "anymore. It will be removed in a future version.",
1357 G_OBJECT_TYPE_NAME (object), pspec->name);
1360 /* provide a copy to work from, convert (if necessary) and validate */
1361 g_value_init (&tmp_value, pspec->value_type);
1362 if (!g_value_transform (value, &tmp_value))
1363 g_warning ("unable to set property '%s' of type '%s' from value of type '%s'",
1365 g_type_name (pspec->value_type),
1366 G_VALUE_TYPE_NAME (value));
1367 else if (g_param_value_validate (pspec, &tmp_value) && !(pspec->flags & G_PARAM_LAX_VALIDATION))
1369 gchar *contents = g_strdup_value_contents (value);
1371 g_warning ("value \"%s\" of type '%s' is invalid or out of range for property '%s' of type '%s'",
1373 G_VALUE_TYPE_NAME (value),
1375 g_type_name (pspec->value_type));
1380 GParamSpec *notify_pspec;
1382 class->set_property (object, param_id, &tmp_value, pspec);
1384 notify_pspec = get_notify_pspec (pspec);
1386 if (notify_pspec != NULL)
1387 g_object_notify_queue_add (object, nqueue, notify_pspec);
1389 g_value_unset (&tmp_value);
1393 object_interface_check_properties (gpointer check_data,
1396 GTypeInterface *iface_class = g_iface;
1397 GObjectClass *class;
1398 GType iface_type = iface_class->g_type;
1399 GParamSpec **pspecs;
1402 class = g_type_class_ref (iface_class->g_instance_type);
1404 if (!G_IS_OBJECT_CLASS (class))
1407 pspecs = g_param_spec_pool_list (pspec_pool, iface_type, &n);
1411 GParamSpec *class_pspec = g_param_spec_pool_lookup (pspec_pool,
1413 G_OBJECT_CLASS_TYPE (class),
1418 g_critical ("Object class %s doesn't implement property "
1419 "'%s' from interface '%s'",
1420 g_type_name (G_OBJECT_CLASS_TYPE (class)),
1422 g_type_name (iface_type));
1427 /* We do a number of checks on the properties of an interface to
1428 * make sure that all classes implementing the interface are
1429 * overriding the properties in a sane way.
1431 * We do the checks in order of importance so that we can give
1432 * more useful error messages first.
1434 * First, we check that the implementation doesn't remove the
1435 * basic functionality (readability, writability) advertised by
1436 * the interface. Next, we check that it doesn't introduce
1437 * additional restrictions (such as construct-only). Finally, we
1438 * make sure the types are compatible.
1441 #define SUBSET(a,b,mask) (((a) & ~(b) & (mask)) == 0)
1442 /* If the property on the interface is readable then the
1443 * implementation must be readable. If the interface is writable
1444 * then the implementation must be writable.
1446 if (!SUBSET (pspecs[n]->flags, class_pspec->flags, G_PARAM_READABLE | G_PARAM_WRITABLE))
1448 g_critical ("Flags for property '%s' on class '%s' remove functionality compared with the "
1449 "property on interface '%s'\n", pspecs[n]->name,
1450 g_type_name (G_OBJECT_CLASS_TYPE (class)), g_type_name (iface_type));
1454 /* If the property on the interface is writable then we need to
1455 * make sure the implementation doesn't introduce new restrictions
1456 * on that writability (ie: construct-only).
1458 * If the interface was not writable to begin with then we don't
1459 * really have any problems here because "writable at construct
1460 * type only" is still more permissive than "read only".
1462 if (pspecs[n]->flags & G_PARAM_WRITABLE)
1464 if (!SUBSET (class_pspec->flags, pspecs[n]->flags, G_PARAM_CONSTRUCT_ONLY))
1466 g_critical ("Flags for property '%s' on class '%s' introduce additional restrictions on "
1467 "writability compared with the property on interface '%s'\n", pspecs[n]->name,
1468 g_type_name (G_OBJECT_CLASS_TYPE (class)), g_type_name (iface_type));
1474 /* If the property on the interface is readable then we are
1475 * effectively advertising that reading the property will return a
1476 * value of a specific type. All implementations of the interface
1477 * need to return items of this type -- but may be more
1478 * restrictive. For example, it is legal to have:
1480 * GtkWidget *get_item();
1482 * that is implemented by a function that always returns a
1483 * GtkEntry. In short: readability implies that the
1484 * implementation value type must be equal or more restrictive.
1486 * Similarly, if the property on the interface is writable then
1487 * must be able to accept the property being set to any value of
1488 * that type, including subclasses. In this case, we may also be
1489 * less restrictive. For example, it is legal to have:
1491 * set_item (GtkEntry *);
1493 * that is implemented by a function that will actually work with
1494 * any GtkWidget. In short: writability implies that the
1495 * implementation value type must be equal or less restrictive.
1497 * In the case that the property is both readable and writable
1498 * then the only way that both of the above can be satisfied is
1499 * with a type that is exactly equal.
1501 switch (pspecs[n]->flags & (G_PARAM_READABLE | G_PARAM_WRITABLE))
1503 case G_PARAM_READABLE | G_PARAM_WRITABLE:
1504 /* class pspec value type must have exact equality with interface */
1505 if (pspecs[n]->value_type != class_pspec->value_type)
1506 g_critical ("Read/writable property '%s' on class '%s' has type '%s' which is not exactly equal to the "
1507 "type '%s' of the property on the interface '%s'\n", pspecs[n]->name,
1508 g_type_name (G_OBJECT_CLASS_TYPE (class)), g_type_name (G_PARAM_SPEC_VALUE_TYPE (class_pspec)),
1509 g_type_name (G_PARAM_SPEC_VALUE_TYPE (pspecs[n])), g_type_name (iface_type));
1512 case G_PARAM_READABLE:
1513 /* class pspec value type equal or more restrictive than interface */
1514 if (!g_type_is_a (class_pspec->value_type, pspecs[n]->value_type))
1515 g_critical ("Read-only property '%s' on class '%s' has type '%s' which is not equal to or more "
1516 "restrictive than the type '%s' of the property on the interface '%s'\n", pspecs[n]->name,
1517 g_type_name (G_OBJECT_CLASS_TYPE (class)), g_type_name (G_PARAM_SPEC_VALUE_TYPE (class_pspec)),
1518 g_type_name (G_PARAM_SPEC_VALUE_TYPE (pspecs[n])), g_type_name (iface_type));
1521 case G_PARAM_WRITABLE:
1522 /* class pspec value type equal or less restrictive than interface */
1523 if (!g_type_is_a (pspecs[n]->value_type, class_pspec->value_type))
1524 g_critical ("Write-only property '%s' on class '%s' has type '%s' which is not equal to or less "
1525 "restrictive than the type '%s' of the property on the interface '%s' \n", pspecs[n]->name,
1526 g_type_name (G_OBJECT_CLASS_TYPE (class)), g_type_name (G_PARAM_SPEC_VALUE_TYPE (class_pspec)),
1527 g_type_name (G_PARAM_SPEC_VALUE_TYPE (pspecs[n])), g_type_name (iface_type));
1531 g_assert_not_reached ();
1537 g_type_class_unref (class);
1541 g_object_get_type (void)
1543 return G_TYPE_OBJECT;
1547 * g_object_new: (skip)
1548 * @object_type: the type id of the #GObject subtype to instantiate
1549 * @first_property_name: the name of the first property
1550 * @...: the value of the first property, followed optionally by more
1551 * name/value pairs, followed by %NULL
1553 * Creates a new instance of a #GObject subtype and sets its properties.
1555 * Construction parameters (see #G_PARAM_CONSTRUCT, #G_PARAM_CONSTRUCT_ONLY)
1556 * which are not explicitly specified are set to their default values.
1558 * Returns: (transfer full): a new instance of @object_type
1561 g_object_new (GType object_type,
1562 const gchar *first_property_name,
1568 g_return_val_if_fail (G_TYPE_IS_OBJECT (object_type), NULL);
1570 /* short circuit for calls supplying no properties */
1571 if (!first_property_name)
1572 return g_object_newv (object_type, 0, NULL);
1574 va_start (var_args, first_property_name);
1575 object = g_object_new_valist (object_type, first_property_name, var_args);
1582 g_object_new_with_custom_constructor (GObjectClass *class,
1583 GObjectConstructParam *params,
1586 GObjectNotifyQueue *nqueue = NULL;
1587 gboolean newly_constructed;
1588 GObjectConstructParam *cparams;
1596 /* If we have ->constructed() then we have to do a lot more work.
1597 * It's possible that this is a singleton and it's also possible
1598 * that the user's constructor() will attempt to modify the values
1599 * that we pass in, so we'll need to allocate copies of them.
1600 * It's also possible that the user may attempt to call
1601 * g_object_set() from inside of their constructor, so we need to
1602 * add ourselves to a list of objects for which that is allowed
1603 * while their constructor() is running.
1606 /* Create the array of GObjectConstructParams for constructor() */
1607 n_cparams = g_slist_length (class->construct_properties);
1608 cparams = g_new (GObjectConstructParam, n_cparams);
1609 cvalues = g_new0 (GValue, n_cparams);
1613 /* As above, we may find the value in the passed-in params list.
1615 * If we have the value passed in then we can use the GValue from
1616 * it directly because it is safe to modify. If we use the
1617 * default value from the class, we had better not pass that in
1618 * and risk it being modified, so we create a new one.
1620 for (node = class->construct_properties; node; node = node->next)
1627 value = NULL; /* to silence gcc... */
1629 for (j = 0; j < n_params; j++)
1630 if (params[j].pspec == pspec)
1632 value = params[j].value;
1638 value = &cvalues[cvals_used++];
1639 g_value_init (value, pspec->value_type);
1640 g_param_value_set_default (pspec, value);
1643 cparams[i].pspec = pspec;
1644 cparams[i].value = value;
1648 /* construct object from construction parameters */
1649 object = class->constructor (class->g_type_class.g_type, n_cparams, cparams);
1650 /* free construction values */
1652 while (cvals_used--)
1653 g_value_unset (&cvalues[cvals_used]);
1656 /* There is code in the wild that relies on being able to return NULL
1657 * from its custom constructor. This was never a supported operation,
1658 * but since the code is already out there...
1662 g_critical ("Custom constructor for class %s returned NULL (which is invalid). "
1663 "Please use GInitable instead.", G_OBJECT_CLASS_NAME (class));
1667 /* g_object_init() will have marked the object as being in-construction.
1668 * Check if the returned object still is so marked, or if this is an
1669 * already-existing singleton (in which case we should not do 'constructed').
1671 newly_constructed = object_in_construction (object);
1672 if (newly_constructed)
1673 g_datalist_id_set_data (&object->qdata, quark_in_construction, NULL);
1675 if (CLASS_HAS_PROPS (class))
1677 /* If this object was newly_constructed then g_object_init()
1678 * froze the queue. We need to freeze it here in order to get
1679 * the handle so that we can thaw it below (otherwise it will
1680 * be frozen forever).
1682 * We also want to do a freeze if we have any params to set,
1683 * even on a non-newly_constructed object.
1685 * It's possible that we have the case of non-newly created
1686 * singleton and all of the passed-in params were construct
1687 * properties so n_params > 0 but we will actually set no
1688 * properties. This is a pretty lame case to optimise, so
1689 * just ignore it and freeze anyway.
1691 if (newly_constructed || n_params)
1692 nqueue = g_object_notify_queue_freeze (object, FALSE);
1694 /* Remember: if it was newly_constructed then g_object_init()
1695 * already did a freeze, so we now have two. Release one.
1697 if (newly_constructed)
1698 g_object_notify_queue_thaw (object, nqueue);
1701 /* run 'constructed' handler if there is a custom one */
1702 if (newly_constructed && CLASS_HAS_CUSTOM_CONSTRUCTED (class))
1703 class->constructed (object);
1705 /* set remaining properties */
1706 for (i = 0; i < n_params; i++)
1707 if (!(params[i].pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY)))
1708 object_set_property (object, params[i].pspec, params[i].value, nqueue);
1710 /* If nqueue is non-NULL then we are frozen. Thaw it. */
1712 g_object_notify_queue_thaw (object, nqueue);
1718 g_object_new_internal (GObjectClass *class,
1719 GObjectConstructParam *params,
1722 GObjectNotifyQueue *nqueue = NULL;
1725 if G_UNLIKELY (CLASS_HAS_CUSTOM_CONSTRUCTOR (class))
1726 return g_object_new_with_custom_constructor (class, params, n_params);
1728 object = (GObject *) g_type_create_instance (class->g_type_class.g_type);
1730 if (CLASS_HAS_PROPS (class))
1734 /* This will have been setup in g_object_init() */
1735 nqueue = g_datalist_id_get_data (&object->qdata, quark_notify_queue);
1736 g_assert (nqueue != NULL);
1738 /* We will set exactly n_construct_properties construct
1739 * properties, but they may come from either the class default
1740 * values or the passed-in parameter list.
1742 for (node = class->construct_properties; node; node = node->next)
1744 const GValue *value;
1749 value = NULL; /* to silence gcc... */
1751 for (j = 0; j < n_params; j++)
1752 if (params[j].pspec == pspec)
1754 value = params[j].value;
1759 value = g_param_spec_get_default_value (pspec);
1761 object_set_property (object, pspec, value, nqueue);
1765 /* run 'constructed' handler if there is a custom one */
1766 if (CLASS_HAS_CUSTOM_CONSTRUCTED (class))
1767 class->constructed (object);
1773 /* Set remaining properties. The construct properties will
1774 * already have been taken, so set only the non-construct
1777 for (i = 0; i < n_params; i++)
1778 if (!(params[i].pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY)))
1779 object_set_property (object, params[i].pspec, params[i].value, nqueue);
1781 g_object_notify_queue_thaw (object, nqueue);
1789 * @object_type: the type id of the #GObject subtype to instantiate
1790 * @n_parameters: the length of the @parameters array
1791 * @parameters: (array length=n_parameters): an array of #GParameter
1793 * Creates a new instance of a #GObject subtype and sets its properties.
1795 * Construction parameters (see #G_PARAM_CONSTRUCT, #G_PARAM_CONSTRUCT_ONLY)
1796 * which are not explicitly specified are set to their default values.
1798 * Rename to: g_object_new
1799 * Returns: (type GObject.Object) (transfer full): a new instance of
1803 g_object_newv (GType object_type,
1805 GParameter *parameters)
1807 GObjectClass *class, *unref_class = NULL;
1810 g_return_val_if_fail (G_TYPE_IS_OBJECT (object_type), NULL);
1811 g_return_val_if_fail (n_parameters == 0 || parameters != NULL, NULL);
1813 /* Try to avoid thrashing the ref_count if we don't need to (since
1814 * it's a locked operation).
1816 class = g_type_class_peek_static (object_type);
1819 class = unref_class = g_type_class_ref (object_type);
1823 GObjectConstructParam *cparams;
1826 cparams = g_newa (GObjectConstructParam, n_parameters);
1829 for (i = 0; i < n_parameters; i++)
1834 pspec = g_param_spec_pool_lookup (pspec_pool, parameters[i].name, object_type, TRUE);
1836 if G_UNLIKELY (!pspec)
1838 g_critical ("%s: object class '%s' has no property named '%s'",
1839 G_STRFUNC, g_type_name (object_type), parameters[i].name);
1843 if G_UNLIKELY (~pspec->flags & G_PARAM_WRITABLE)
1845 g_critical ("%s: property '%s' of object class '%s' is not writable",
1846 G_STRFUNC, pspec->name, g_type_name (object_type));
1850 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
1852 for (k = 0; k < j; k++)
1853 if (cparams[k].pspec == pspec)
1855 if G_UNLIKELY (k != j)
1857 g_critical ("%s: construct property '%s' for type '%s' cannot be set twice",
1858 G_STRFUNC, parameters[i].name, g_type_name (object_type));
1863 cparams[j].pspec = pspec;
1864 cparams[j].value = ¶meters[i].value;
1868 object = g_object_new_internal (class, cparams, j);
1871 /* Fast case: no properties passed in. */
1872 object = g_object_new_internal (class, NULL, 0);
1875 g_type_class_unref (unref_class);
1881 * g_object_new_valist: (skip)
1882 * @object_type: the type id of the #GObject subtype to instantiate
1883 * @first_property_name: the name of the first property
1884 * @var_args: the value of the first property, followed optionally by more
1885 * name/value pairs, followed by %NULL
1887 * Creates a new instance of a #GObject subtype and sets its properties.
1889 * Construction parameters (see #G_PARAM_CONSTRUCT, #G_PARAM_CONSTRUCT_ONLY)
1890 * which are not explicitly specified are set to their default values.
1892 * Returns: a new instance of @object_type
1895 g_object_new_valist (GType object_type,
1896 const gchar *first_property_name,
1899 GObjectClass *class, *unref_class = NULL;
1902 g_return_val_if_fail (G_TYPE_IS_OBJECT (object_type), NULL);
1904 /* Try to avoid thrashing the ref_count if we don't need to (since
1905 * it's a locked operation).
1907 class = g_type_class_peek_static (object_type);
1910 class = unref_class = g_type_class_ref (object_type);
1912 if (first_property_name)
1914 GObjectConstructParam stack_params[16];
1915 GObjectConstructParam *params;
1919 name = first_property_name;
1920 params = stack_params;
1924 gchar *error = NULL;
1928 pspec = g_param_spec_pool_lookup (pspec_pool, name, object_type, TRUE);
1930 if G_UNLIKELY (!pspec)
1932 g_critical ("%s: object class '%s' has no property named '%s'",
1933 G_STRFUNC, g_type_name (object_type), name);
1934 /* Can't continue because arg list will be out of sync. */
1938 if G_UNLIKELY (~pspec->flags & G_PARAM_WRITABLE)
1940 g_critical ("%s: property '%s' of object class '%s' is not writable",
1941 G_STRFUNC, pspec->name, g_type_name (object_type));
1945 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
1947 for (i = 0; i < n_params; i++)
1948 if (params[i].pspec == pspec)
1950 if G_UNLIKELY (i != n_params)
1952 g_critical ("%s: property '%s' for type '%s' cannot be set twice",
1953 G_STRFUNC, name, g_type_name (object_type));
1960 params = g_new (GObjectConstructParam, n_params + 1);
1961 memcpy (params, stack_params, sizeof stack_params);
1963 else if (n_params > 16)
1964 params = g_renew (GObjectConstructParam, params, n_params + 1);
1966 params[n_params].pspec = pspec;
1967 params[n_params].value = g_newa (GValue, 1);
1968 memset (params[n_params].value, 0, sizeof (GValue));
1970 G_VALUE_COLLECT_INIT (params[n_params].value, pspec->value_type, var_args, 0, &error);
1974 g_critical ("%s: %s", G_STRFUNC, error);
1975 g_value_unset (params[n_params].value);
1982 while ((name = va_arg (var_args, const gchar *)));
1984 object = g_object_new_internal (class, params, n_params);
1987 g_value_unset (params[n_params].value);
1989 if (params != stack_params)
1993 /* Fast case: no properties passed in. */
1994 object = g_object_new_internal (class, NULL, 0);
1997 g_type_class_unref (unref_class);
2003 g_object_constructor (GType type,
2004 guint n_construct_properties,
2005 GObjectConstructParam *construct_params)
2010 object = (GObject*) g_type_create_instance (type);
2012 /* set construction parameters */
2013 if (n_construct_properties)
2015 GObjectNotifyQueue *nqueue = g_object_notify_queue_freeze (object, FALSE);
2017 /* set construct properties */
2018 while (n_construct_properties--)
2020 GValue *value = construct_params->value;
2021 GParamSpec *pspec = construct_params->pspec;
2024 object_set_property (object, pspec, value, nqueue);
2026 g_object_notify_queue_thaw (object, nqueue);
2027 /* the notification queue is still frozen from g_object_init(), so
2028 * we don't need to handle it here, g_object_newv() takes
2037 g_object_constructed (GObject *object)
2039 /* empty default impl to allow unconditional upchaining */
2043 * g_object_set_valist: (skip)
2044 * @object: a #GObject
2045 * @first_property_name: name of the first property to set
2046 * @var_args: value for the first property, followed optionally by more
2047 * name/value pairs, followed by %NULL
2049 * Sets properties on an object.
2052 g_object_set_valist (GObject *object,
2053 const gchar *first_property_name,
2056 GObjectNotifyQueue *nqueue;
2059 g_return_if_fail (G_IS_OBJECT (object));
2061 g_object_ref (object);
2062 nqueue = g_object_notify_queue_freeze (object, FALSE);
2064 name = first_property_name;
2067 GValue value = G_VALUE_INIT;
2069 gchar *error = NULL;
2071 pspec = g_param_spec_pool_lookup (pspec_pool,
2073 G_OBJECT_TYPE (object),
2077 g_warning ("%s: object class '%s' has no property named '%s'",
2079 G_OBJECT_TYPE_NAME (object),
2083 if (!(pspec->flags & G_PARAM_WRITABLE))
2085 g_warning ("%s: property '%s' of object class '%s' is not writable",
2088 G_OBJECT_TYPE_NAME (object));
2091 if ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) && !object_in_construction (object))
2093 g_warning ("%s: construct property \"%s\" for object '%s' can't be set after construction",
2094 G_STRFUNC, pspec->name, G_OBJECT_TYPE_NAME (object));
2098 G_VALUE_COLLECT_INIT (&value, pspec->value_type, var_args,
2102 g_warning ("%s: %s", G_STRFUNC, error);
2104 g_value_unset (&value);
2108 object_set_property (object, pspec, &value, nqueue);
2109 g_value_unset (&value);
2111 name = va_arg (var_args, gchar*);
2114 g_object_notify_queue_thaw (object, nqueue);
2115 g_object_unref (object);
2119 * g_object_get_valist: (skip)
2120 * @object: a #GObject
2121 * @first_property_name: name of the first property to get
2122 * @var_args: return location for the first property, followed optionally by more
2123 * name/return location pairs, followed by %NULL
2125 * Gets properties of an object.
2127 * In general, a copy is made of the property contents and the caller
2128 * is responsible for freeing the memory in the appropriate manner for
2129 * the type, for instance by calling g_free() or g_object_unref().
2131 * See g_object_get().
2134 g_object_get_valist (GObject *object,
2135 const gchar *first_property_name,
2140 g_return_if_fail (G_IS_OBJECT (object));
2142 g_object_ref (object);
2144 name = first_property_name;
2148 GValue value = G_VALUE_INIT;
2152 pspec = g_param_spec_pool_lookup (pspec_pool,
2154 G_OBJECT_TYPE (object),
2158 g_warning ("%s: object class '%s' has no property named '%s'",
2160 G_OBJECT_TYPE_NAME (object),
2164 if (!(pspec->flags & G_PARAM_READABLE))
2166 g_warning ("%s: property '%s' of object class '%s' is not readable",
2169 G_OBJECT_TYPE_NAME (object));
2173 g_value_init (&value, pspec->value_type);
2175 object_get_property (object, pspec, &value);
2177 G_VALUE_LCOPY (&value, var_args, 0, &error);
2180 g_warning ("%s: %s", G_STRFUNC, error);
2182 g_value_unset (&value);
2186 g_value_unset (&value);
2188 name = va_arg (var_args, gchar*);
2191 g_object_unref (object);
2195 * g_object_set: (skip)
2196 * @object: a #GObject
2197 * @first_property_name: name of the first property to set
2198 * @...: value for the first property, followed optionally by more
2199 * name/value pairs, followed by %NULL
2201 * Sets properties on an object.
2203 * Note that the "notify" signals are queued and only emitted (in
2204 * reverse order) after all properties have been set. See
2205 * g_object_freeze_notify().
2208 g_object_set (gpointer _object,
2209 const gchar *first_property_name,
2212 GObject *object = _object;
2215 g_return_if_fail (G_IS_OBJECT (object));
2217 va_start (var_args, first_property_name);
2218 g_object_set_valist (object, first_property_name, var_args);
2223 * g_object_get: (skip)
2224 * @object: a #GObject
2225 * @first_property_name: name of the first property to get
2226 * @...: return location for the first property, followed optionally by more
2227 * name/return location pairs, followed by %NULL
2229 * Gets properties of an object.
2231 * In general, a copy is made of the property contents and the caller
2232 * is responsible for freeing the memory in the appropriate manner for
2233 * the type, for instance by calling g_free() or g_object_unref().
2236 * <title>Using g_object_get(<!-- -->)</title>
2237 * An example of using g_object_get() to get the contents
2238 * of three properties - one of type #G_TYPE_INT,
2239 * one of type #G_TYPE_STRING, and one of type #G_TYPE_OBJECT:
2245 * g_object_get (my_object,
2246 * "int-property", &intval,
2247 * "str-property", &strval,
2248 * "obj-property", &objval,
2251 * // Do something with intval, strval, objval
2254 * g_object_unref (objval);
2259 g_object_get (gpointer _object,
2260 const gchar *first_property_name,
2263 GObject *object = _object;
2266 g_return_if_fail (G_IS_OBJECT (object));
2268 va_start (var_args, first_property_name);
2269 g_object_get_valist (object, first_property_name, var_args);
2274 * g_object_set_property:
2275 * @object: a #GObject
2276 * @property_name: the name of the property to set
2279 * Sets a property on an object.
2282 g_object_set_property (GObject *object,
2283 const gchar *property_name,
2284 const GValue *value)
2286 GObjectNotifyQueue *nqueue;
2289 g_return_if_fail (G_IS_OBJECT (object));
2290 g_return_if_fail (property_name != NULL);
2291 g_return_if_fail (G_IS_VALUE (value));
2293 g_object_ref (object);
2294 nqueue = g_object_notify_queue_freeze (object, FALSE);
2296 pspec = g_param_spec_pool_lookup (pspec_pool,
2298 G_OBJECT_TYPE (object),
2301 g_warning ("%s: object class '%s' has no property named '%s'",
2303 G_OBJECT_TYPE_NAME (object),
2305 else if (!(pspec->flags & G_PARAM_WRITABLE))
2306 g_warning ("%s: property '%s' of object class '%s' is not writable",
2309 G_OBJECT_TYPE_NAME (object));
2310 else if ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) && !object_in_construction (object))
2311 g_warning ("%s: construct property \"%s\" for object '%s' can't be set after construction",
2312 G_STRFUNC, pspec->name, G_OBJECT_TYPE_NAME (object));
2314 object_set_property (object, pspec, value, nqueue);
2316 g_object_notify_queue_thaw (object, nqueue);
2317 g_object_unref (object);
2321 * g_object_get_property:
2322 * @object: a #GObject
2323 * @property_name: the name of the property to get
2324 * @value: return location for the property value
2326 * Gets a property of an object. @value must have been initialized to the
2327 * expected type of the property (or a type to which the expected type can be
2328 * transformed) using g_value_init().
2330 * In general, a copy is made of the property contents and the caller is
2331 * responsible for freeing the memory by calling g_value_unset().
2333 * Note that g_object_get_property() is really intended for language
2334 * bindings, g_object_get() is much more convenient for C programming.
2337 g_object_get_property (GObject *object,
2338 const gchar *property_name,
2343 g_return_if_fail (G_IS_OBJECT (object));
2344 g_return_if_fail (property_name != NULL);
2345 g_return_if_fail (G_IS_VALUE (value));
2347 g_object_ref (object);
2349 pspec = g_param_spec_pool_lookup (pspec_pool,
2351 G_OBJECT_TYPE (object),
2354 g_warning ("%s: object class '%s' has no property named '%s'",
2356 G_OBJECT_TYPE_NAME (object),
2358 else if (!(pspec->flags & G_PARAM_READABLE))
2359 g_warning ("%s: property '%s' of object class '%s' is not readable",
2362 G_OBJECT_TYPE_NAME (object));
2365 GValue *prop_value, tmp_value = G_VALUE_INIT;
2367 /* auto-conversion of the callers value type
2369 if (G_VALUE_TYPE (value) == pspec->value_type)
2371 g_value_reset (value);
2374 else if (!g_value_type_transformable (pspec->value_type, G_VALUE_TYPE (value)))
2376 g_warning ("%s: can't retrieve property '%s' of type '%s' as value of type '%s'",
2377 G_STRFUNC, pspec->name,
2378 g_type_name (pspec->value_type),
2379 G_VALUE_TYPE_NAME (value));
2380 g_object_unref (object);
2385 g_value_init (&tmp_value, pspec->value_type);
2386 prop_value = &tmp_value;
2388 object_get_property (object, pspec, prop_value);
2389 if (prop_value != value)
2391 g_value_transform (prop_value, value);
2392 g_value_unset (&tmp_value);
2396 g_object_unref (object);
2400 * g_object_connect: (skip)
2401 * @object: a #GObject
2402 * @signal_spec: the spec for the first signal
2403 * @...: #GCallback for the first signal, followed by data for the
2404 * first signal, followed optionally by more signal
2405 * spec/callback/data triples, followed by %NULL
2407 * A convenience function to connect multiple signals at once.
2409 * The signal specs expected by this function have the form
2410 * "modifier::signal_name", where modifier can be one of the following:
2413 * <term>signal</term>
2415 * equivalent to <literal>g_signal_connect_data (..., NULL, 0)</literal>
2416 * </para></listitem>
2419 * <term>object_signal</term>
2420 * <term>object-signal</term>
2422 * equivalent to <literal>g_signal_connect_object (..., 0)</literal>
2423 * </para></listitem>
2426 * <term>swapped_signal</term>
2427 * <term>swapped-signal</term>
2429 * equivalent to <literal>g_signal_connect_data (..., NULL, G_CONNECT_SWAPPED)</literal>
2430 * </para></listitem>
2433 * <term>swapped_object_signal</term>
2434 * <term>swapped-object-signal</term>
2436 * equivalent to <literal>g_signal_connect_object (..., G_CONNECT_SWAPPED)</literal>
2437 * </para></listitem>
2440 * <term>signal_after</term>
2441 * <term>signal-after</term>
2443 * equivalent to <literal>g_signal_connect_data (..., NULL, G_CONNECT_AFTER)</literal>
2444 * </para></listitem>
2447 * <term>object_signal_after</term>
2448 * <term>object-signal-after</term>
2450 * equivalent to <literal>g_signal_connect_object (..., G_CONNECT_AFTER)</literal>
2451 * </para></listitem>
2454 * <term>swapped_signal_after</term>
2455 * <term>swapped-signal-after</term>
2457 * equivalent to <literal>g_signal_connect_data (..., NULL, G_CONNECT_SWAPPED | G_CONNECT_AFTER)</literal>
2458 * </para></listitem>
2461 * <term>swapped_object_signal_after</term>
2462 * <term>swapped-object-signal-after</term>
2464 * equivalent to <literal>g_signal_connect_object (..., G_CONNECT_SWAPPED | G_CONNECT_AFTER)</literal>
2465 * </para></listitem>
2470 * menu->toplevel = g_object_connect (g_object_new (GTK_TYPE_WINDOW,
2471 * "type", GTK_WINDOW_POPUP,
2474 * "signal::event", gtk_menu_window_event, menu,
2475 * "signal::size_request", gtk_menu_window_size_request, menu,
2476 * "signal::destroy", gtk_widget_destroyed, &menu->toplevel,
2480 * Returns: (transfer none): @object
2483 g_object_connect (gpointer _object,
2484 const gchar *signal_spec,
2487 GObject *object = _object;
2490 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
2491 g_return_val_if_fail (object->ref_count > 0, object);
2493 va_start (var_args, signal_spec);
2496 GCallback callback = va_arg (var_args, GCallback);
2497 gpointer data = va_arg (var_args, gpointer);
2499 if (strncmp (signal_spec, "signal::", 8) == 0)
2500 g_signal_connect_data (object, signal_spec + 8,
2501 callback, data, NULL,
2503 else if (strncmp (signal_spec, "object_signal::", 15) == 0 ||
2504 strncmp (signal_spec, "object-signal::", 15) == 0)
2505 g_signal_connect_object (object, signal_spec + 15,
2508 else if (strncmp (signal_spec, "swapped_signal::", 16) == 0 ||
2509 strncmp (signal_spec, "swapped-signal::", 16) == 0)
2510 g_signal_connect_data (object, signal_spec + 16,
2511 callback, data, NULL,
2513 else if (strncmp (signal_spec, "swapped_object_signal::", 23) == 0 ||
2514 strncmp (signal_spec, "swapped-object-signal::", 23) == 0)
2515 g_signal_connect_object (object, signal_spec + 23,
2518 else if (strncmp (signal_spec, "signal_after::", 14) == 0 ||
2519 strncmp (signal_spec, "signal-after::", 14) == 0)
2520 g_signal_connect_data (object, signal_spec + 14,
2521 callback, data, NULL,
2523 else if (strncmp (signal_spec, "object_signal_after::", 21) == 0 ||
2524 strncmp (signal_spec, "object-signal-after::", 21) == 0)
2525 g_signal_connect_object (object, signal_spec + 21,
2528 else if (strncmp (signal_spec, "swapped_signal_after::", 22) == 0 ||
2529 strncmp (signal_spec, "swapped-signal-after::", 22) == 0)
2530 g_signal_connect_data (object, signal_spec + 22,
2531 callback, data, NULL,
2532 G_CONNECT_SWAPPED | G_CONNECT_AFTER);
2533 else if (strncmp (signal_spec, "swapped_object_signal_after::", 29) == 0 ||
2534 strncmp (signal_spec, "swapped-object-signal-after::", 29) == 0)
2535 g_signal_connect_object (object, signal_spec + 29,
2537 G_CONNECT_SWAPPED | G_CONNECT_AFTER);
2540 g_warning ("%s: invalid signal spec \"%s\"", G_STRFUNC, signal_spec);
2543 signal_spec = va_arg (var_args, gchar*);
2551 * g_object_disconnect: (skip)
2552 * @object: a #GObject
2553 * @signal_spec: the spec for the first signal
2554 * @...: #GCallback for the first signal, followed by data for the first signal,
2555 * followed optionally by more signal spec/callback/data triples,
2558 * A convenience function to disconnect multiple signals at once.
2560 * The signal specs expected by this function have the form
2561 * "any_signal", which means to disconnect any signal with matching
2562 * callback and data, or "any_signal::signal_name", which only
2563 * disconnects the signal named "signal_name".
2566 g_object_disconnect (gpointer _object,
2567 const gchar *signal_spec,
2570 GObject *object = _object;
2573 g_return_if_fail (G_IS_OBJECT (object));
2574 g_return_if_fail (object->ref_count > 0);
2576 va_start (var_args, signal_spec);
2579 GCallback callback = va_arg (var_args, GCallback);
2580 gpointer data = va_arg (var_args, gpointer);
2581 guint sid = 0, detail = 0, mask = 0;
2583 if (strncmp (signal_spec, "any_signal::", 12) == 0 ||
2584 strncmp (signal_spec, "any-signal::", 12) == 0)
2587 mask = G_SIGNAL_MATCH_ID | G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA;
2589 else if (strcmp (signal_spec, "any_signal") == 0 ||
2590 strcmp (signal_spec, "any-signal") == 0)
2593 mask = G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA;
2597 g_warning ("%s: invalid signal spec \"%s\"", G_STRFUNC, signal_spec);
2601 if ((mask & G_SIGNAL_MATCH_ID) &&
2602 !g_signal_parse_name (signal_spec, G_OBJECT_TYPE (object), &sid, &detail, FALSE))
2603 g_warning ("%s: invalid signal name \"%s\"", G_STRFUNC, signal_spec);
2604 else if (!g_signal_handlers_disconnect_matched (object, mask | (detail ? G_SIGNAL_MATCH_DETAIL : 0),
2606 NULL, (gpointer)callback, data))
2607 g_warning ("%s: signal handler %p(%p) is not connected", G_STRFUNC, callback, data);
2608 signal_spec = va_arg (var_args, gchar*);
2619 } weak_refs[1]; /* flexible array */
2623 weak_refs_notify (gpointer data)
2625 WeakRefStack *wstack = data;
2628 for (i = 0; i < wstack->n_weak_refs; i++)
2629 wstack->weak_refs[i].notify (wstack->weak_refs[i].data, wstack->object);
2634 * g_object_weak_ref: (skip)
2635 * @object: #GObject to reference weakly
2636 * @notify: callback to invoke before the object is freed
2637 * @data: extra data to pass to notify
2639 * Adds a weak reference callback to an object. Weak references are
2640 * used for notification when an object is finalized. They are called
2641 * "weak references" because they allow you to safely hold a pointer
2642 * to an object without calling g_object_ref() (g_object_ref() adds a
2643 * strong reference, that is, forces the object to stay alive).
2645 * Note that the weak references created by this method are not
2646 * thread-safe: they cannot safely be used in one thread if the
2647 * object's last g_object_unref() might happen in another thread.
2648 * Use #GWeakRef if thread-safety is required.
2651 g_object_weak_ref (GObject *object,
2655 WeakRefStack *wstack;
2658 g_return_if_fail (G_IS_OBJECT (object));
2659 g_return_if_fail (notify != NULL);
2660 g_return_if_fail (object->ref_count >= 1);
2662 G_LOCK (weak_refs_mutex);
2663 wstack = g_datalist_id_remove_no_notify (&object->qdata, quark_weak_refs);
2666 i = wstack->n_weak_refs++;
2667 wstack = g_realloc (wstack, sizeof (*wstack) + sizeof (wstack->weak_refs[0]) * i);
2671 wstack = g_renew (WeakRefStack, NULL, 1);
2672 wstack->object = object;
2673 wstack->n_weak_refs = 1;
2676 wstack->weak_refs[i].notify = notify;
2677 wstack->weak_refs[i].data = data;
2678 g_datalist_id_set_data_full (&object->qdata, quark_weak_refs, wstack, weak_refs_notify);
2679 G_UNLOCK (weak_refs_mutex);
2683 * g_object_weak_unref: (skip)
2684 * @object: #GObject to remove a weak reference from
2685 * @notify: callback to search for
2686 * @data: data to search for
2688 * Removes a weak reference callback to an object.
2691 g_object_weak_unref (GObject *object,
2695 WeakRefStack *wstack;
2696 gboolean found_one = FALSE;
2698 g_return_if_fail (G_IS_OBJECT (object));
2699 g_return_if_fail (notify != NULL);
2701 G_LOCK (weak_refs_mutex);
2702 wstack = g_datalist_id_get_data (&object->qdata, quark_weak_refs);
2707 for (i = 0; i < wstack->n_weak_refs; i++)
2708 if (wstack->weak_refs[i].notify == notify &&
2709 wstack->weak_refs[i].data == data)
2712 wstack->n_weak_refs -= 1;
2713 if (i != wstack->n_weak_refs)
2714 wstack->weak_refs[i] = wstack->weak_refs[wstack->n_weak_refs];
2719 G_UNLOCK (weak_refs_mutex);
2721 g_warning ("%s: couldn't find weak ref %p(%p)", G_STRFUNC, notify, data);
2725 * g_object_add_weak_pointer: (skip)
2726 * @object: The object that should be weak referenced.
2727 * @weak_pointer_location: (inout): The memory address of a pointer.
2729 * Adds a weak reference from weak_pointer to @object to indicate that
2730 * the pointer located at @weak_pointer_location is only valid during
2731 * the lifetime of @object. When the @object is finalized,
2732 * @weak_pointer will be set to %NULL.
2734 * Note that as with g_object_weak_ref(), the weak references created by
2735 * this method are not thread-safe: they cannot safely be used in one
2736 * thread if the object's last g_object_unref() might happen in another
2737 * thread. Use #GWeakRef if thread-safety is required.
2740 g_object_add_weak_pointer (GObject *object,
2741 gpointer *weak_pointer_location)
2743 g_return_if_fail (G_IS_OBJECT (object));
2744 g_return_if_fail (weak_pointer_location != NULL);
2746 g_object_weak_ref (object,
2747 (GWeakNotify) g_nullify_pointer,
2748 weak_pointer_location);
2752 * g_object_remove_weak_pointer: (skip)
2753 * @object: The object that is weak referenced.
2754 * @weak_pointer_location: (inout): The memory address of a pointer.
2756 * Removes a weak reference from @object that was previously added
2757 * using g_object_add_weak_pointer(). The @weak_pointer_location has
2758 * to match the one used with g_object_add_weak_pointer().
2761 g_object_remove_weak_pointer (GObject *object,
2762 gpointer *weak_pointer_location)
2764 g_return_if_fail (G_IS_OBJECT (object));
2765 g_return_if_fail (weak_pointer_location != NULL);
2767 g_object_weak_unref (object,
2768 (GWeakNotify) g_nullify_pointer,
2769 weak_pointer_location);
2773 object_floating_flag_handler (GObject *object,
2779 case +1: /* force floating 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 | OBJECT_FLOATING_FLAG)));
2784 return (gsize) oldvalue & OBJECT_FLOATING_FLAG;
2785 case -1: /* sink if possible */
2787 oldvalue = g_atomic_pointer_get (&object->qdata);
2788 while (!g_atomic_pointer_compare_and_exchange ((void**) &object->qdata, oldvalue,
2789 (gpointer) ((gsize) oldvalue & ~(gsize) OBJECT_FLOATING_FLAG)));
2790 return (gsize) oldvalue & OBJECT_FLOATING_FLAG;
2791 default: /* check floating */
2792 return 0 != ((gsize) g_atomic_pointer_get (&object->qdata) & OBJECT_FLOATING_FLAG);
2797 * g_object_is_floating:
2798 * @object: (type GObject.Object): a #GObject
2800 * Checks whether @object has a <link linkend="floating-ref">floating</link>
2805 * Returns: %TRUE if @object has a floating reference
2808 g_object_is_floating (gpointer _object)
2810 GObject *object = _object;
2811 g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
2812 return floating_flag_handler (object, 0);
2816 * g_object_ref_sink:
2817 * @object: (type GObject.Object): a #GObject
2819 * Increase the reference count of @object, and possibly remove the
2820 * <link linkend="floating-ref">floating</link> reference, if @object
2821 * has a floating reference.
2823 * In other words, if the object is floating, then this call "assumes
2824 * ownership" of the floating reference, converting it to a normal
2825 * reference by clearing the floating flag while leaving the reference
2826 * count unchanged. If the object is not floating, then this call
2827 * adds a new normal reference increasing the reference count by one.
2831 * Returns: (type GObject.Object) (transfer none): @object
2834 g_object_ref_sink (gpointer _object)
2836 GObject *object = _object;
2837 gboolean was_floating;
2838 g_return_val_if_fail (G_IS_OBJECT (object), object);
2839 g_return_val_if_fail (object->ref_count >= 1, object);
2840 g_object_ref (object);
2841 was_floating = floating_flag_handler (object, -1);
2843 g_object_unref (object);
2848 * g_object_force_floating:
2849 * @object: a #GObject
2851 * This function is intended for #GObject implementations to re-enforce a
2852 * <link linkend="floating-ref">floating</link> object reference.
2853 * Doing this is seldom required: all
2854 * #GInitiallyUnowned<!-- -->s are created with a floating reference which
2855 * usually just needs to be sunken by calling g_object_ref_sink().
2860 g_object_force_floating (GObject *object)
2862 g_return_if_fail (G_IS_OBJECT (object));
2863 g_return_if_fail (object->ref_count >= 1);
2865 floating_flag_handler (object, +1);
2870 guint n_toggle_refs;
2872 GToggleNotify notify;
2874 } toggle_refs[1]; /* flexible array */
2878 toggle_refs_notify (GObject *object,
2879 gboolean is_last_ref)
2881 ToggleRefStack tstack, *tstackptr;
2883 G_LOCK (toggle_refs_mutex);
2884 tstackptr = g_datalist_id_get_data (&object->qdata, quark_toggle_refs);
2885 tstack = *tstackptr;
2886 G_UNLOCK (toggle_refs_mutex);
2888 /* Reentrancy here is not as tricky as it seems, because a toggle reference
2889 * will only be notified when there is exactly one of them.
2891 g_assert (tstack.n_toggle_refs == 1);
2892 tstack.toggle_refs[0].notify (tstack.toggle_refs[0].data, tstack.object, is_last_ref);
2896 * g_object_add_toggle_ref: (skip)
2897 * @object: a #GObject
2898 * @notify: a function to call when this reference is the
2899 * last reference to the object, or is no longer
2900 * the last reference.
2901 * @data: data to pass to @notify
2903 * Increases the reference count of the object by one and sets a
2904 * callback to be called when all other references to the object are
2905 * dropped, or when this is already the last reference to the object
2906 * and another reference is established.
2908 * This functionality is intended for binding @object to a proxy
2909 * object managed by another memory manager. This is done with two
2910 * paired references: the strong reference added by
2911 * g_object_add_toggle_ref() and a reverse reference to the proxy
2912 * object which is either a strong reference or weak reference.
2914 * The setup is that when there are no other references to @object,
2915 * only a weak reference is held in the reverse direction from @object
2916 * to the proxy object, but when there are other references held to
2917 * @object, a strong reference is held. The @notify callback is called
2918 * when the reference from @object to the proxy object should be
2919 * <firstterm>toggled</firstterm> from strong to weak (@is_last_ref
2920 * true) or weak to strong (@is_last_ref false).
2922 * Since a (normal) reference must be held to the object before
2923 * calling g_object_add_toggle_ref(), the initial state of the reverse
2924 * link is always strong.
2926 * Multiple toggle references may be added to the same gobject,
2927 * however if there are multiple toggle references to an object, none
2928 * of them will ever be notified until all but one are removed. For
2929 * this reason, you should only ever use a toggle reference if there
2930 * is important state in the proxy object.
2935 g_object_add_toggle_ref (GObject *object,
2936 GToggleNotify notify,
2939 ToggleRefStack *tstack;
2942 g_return_if_fail (G_IS_OBJECT (object));
2943 g_return_if_fail (notify != NULL);
2944 g_return_if_fail (object->ref_count >= 1);
2946 g_object_ref (object);
2948 G_LOCK (toggle_refs_mutex);
2949 tstack = g_datalist_id_remove_no_notify (&object->qdata, quark_toggle_refs);
2952 i = tstack->n_toggle_refs++;
2953 /* allocate i = tstate->n_toggle_refs - 1 positions beyond the 1 declared
2954 * in tstate->toggle_refs */
2955 tstack = g_realloc (tstack, sizeof (*tstack) + sizeof (tstack->toggle_refs[0]) * i);
2959 tstack = g_renew (ToggleRefStack, NULL, 1);
2960 tstack->object = object;
2961 tstack->n_toggle_refs = 1;
2965 /* Set a flag for fast lookup after adding the first toggle reference */
2966 if (tstack->n_toggle_refs == 1)
2967 g_datalist_set_flags (&object->qdata, OBJECT_HAS_TOGGLE_REF_FLAG);
2969 tstack->toggle_refs[i].notify = notify;
2970 tstack->toggle_refs[i].data = data;
2971 g_datalist_id_set_data_full (&object->qdata, quark_toggle_refs, tstack,
2972 (GDestroyNotify)g_free);
2973 G_UNLOCK (toggle_refs_mutex);
2977 * g_object_remove_toggle_ref: (skip)
2978 * @object: a #GObject
2979 * @notify: a function to call when this reference is the
2980 * last reference to the object, or is no longer
2981 * the last reference.
2982 * @data: data to pass to @notify
2984 * Removes a reference added with g_object_add_toggle_ref(). The
2985 * reference count of the object is decreased by one.
2990 g_object_remove_toggle_ref (GObject *object,
2991 GToggleNotify notify,
2994 ToggleRefStack *tstack;
2995 gboolean found_one = FALSE;
2997 g_return_if_fail (G_IS_OBJECT (object));
2998 g_return_if_fail (notify != NULL);
3000 G_LOCK (toggle_refs_mutex);
3001 tstack = g_datalist_id_get_data (&object->qdata, quark_toggle_refs);
3006 for (i = 0; i < tstack->n_toggle_refs; i++)
3007 if (tstack->toggle_refs[i].notify == notify &&
3008 tstack->toggle_refs[i].data == data)
3011 tstack->n_toggle_refs -= 1;
3012 if (i != tstack->n_toggle_refs)
3013 tstack->toggle_refs[i] = tstack->toggle_refs[tstack->n_toggle_refs];
3015 if (tstack->n_toggle_refs == 0)
3016 g_datalist_unset_flags (&object->qdata, OBJECT_HAS_TOGGLE_REF_FLAG);
3021 G_UNLOCK (toggle_refs_mutex);
3024 g_object_unref (object);
3026 g_warning ("%s: couldn't find toggle ref %p(%p)", G_STRFUNC, notify, data);
3031 * @object: (type GObject.Object): a #GObject
3033 * Increases the reference count of @object.
3035 * Returns: (type GObject.Object) (transfer none): the same @object
3038 g_object_ref (gpointer _object)
3040 GObject *object = _object;
3043 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3044 g_return_val_if_fail (object->ref_count > 0, NULL);
3046 #ifdef G_ENABLE_DEBUG
3047 if (g_trap_object_ref == object)
3049 #endif /* G_ENABLE_DEBUG */
3052 old_val = g_atomic_int_add (&object->ref_count, 1);
3054 if (old_val == 1 && OBJECT_HAS_TOGGLE_REF (object))
3055 toggle_refs_notify (object, FALSE);
3057 TRACE (GOBJECT_OBJECT_REF(object,G_TYPE_FROM_INSTANCE(object),old_val));
3064 * @object: (type GObject.Object): a #GObject
3066 * Decreases the reference count of @object. When its reference count
3067 * drops to 0, the object is finalized (i.e. its memory is freed).
3070 g_object_unref (gpointer _object)
3072 GObject *object = _object;
3075 g_return_if_fail (G_IS_OBJECT (object));
3076 g_return_if_fail (object->ref_count > 0);
3078 #ifdef G_ENABLE_DEBUG
3079 if (g_trap_object_ref == object)
3081 #endif /* G_ENABLE_DEBUG */
3083 /* here we want to atomically do: if (ref_count>1) { ref_count--; return; } */
3084 retry_atomic_decrement1:
3085 old_ref = g_atomic_int_get (&object->ref_count);
3088 /* valid if last 2 refs are owned by this call to unref and the toggle_ref */
3089 gboolean has_toggle_ref = OBJECT_HAS_TOGGLE_REF (object);
3091 if (!g_atomic_int_compare_and_exchange ((int *)&object->ref_count, old_ref, old_ref - 1))
3092 goto retry_atomic_decrement1;
3094 TRACE (GOBJECT_OBJECT_UNREF(object,G_TYPE_FROM_INSTANCE(object),old_ref));
3096 /* if we went from 2->1 we need to notify toggle refs if any */
3097 if (old_ref == 2 && has_toggle_ref) /* The last ref being held in this case is owned by the toggle_ref */
3098 toggle_refs_notify (object, TRUE);
3102 GSList **weak_locations;
3104 /* The only way that this object can live at this point is if
3105 * there are outstanding weak references already established
3106 * before we got here.
3108 * If there were not already weak references then no more can be
3109 * established at this time, because the other thread would have
3110 * to hold a strong ref in order to call
3111 * g_object_add_weak_pointer() and then we wouldn't be here.
3113 weak_locations = g_datalist_id_get_data (&object->qdata, quark_weak_locations);
3115 if (weak_locations != NULL)
3117 g_rw_lock_writer_lock (&weak_locations_lock);
3119 /* It is possible that one of the weak references beat us to
3120 * the lock. Make sure the refcount is still what we expected
3123 old_ref = g_atomic_int_get (&object->ref_count);
3126 g_rw_lock_writer_unlock (&weak_locations_lock);
3127 goto retry_atomic_decrement1;
3130 /* We got the lock first, so the object will definitely die
3131 * now. Clear out all the weak references.
3133 while (*weak_locations)
3135 GWeakRef *weak_ref_location = (*weak_locations)->data;
3137 weak_ref_location->priv.p = NULL;
3138 *weak_locations = g_slist_delete_link (*weak_locations, *weak_locations);
3141 g_rw_lock_writer_unlock (&weak_locations_lock);
3144 /* we are about to remove the last reference */
3145 TRACE (GOBJECT_OBJECT_DISPOSE(object,G_TYPE_FROM_INSTANCE(object), 1));
3146 G_OBJECT_GET_CLASS (object)->dispose (object);
3147 TRACE (GOBJECT_OBJECT_DISPOSE_END(object,G_TYPE_FROM_INSTANCE(object), 1));
3149 /* may have been re-referenced meanwhile */
3150 retry_atomic_decrement2:
3151 old_ref = g_atomic_int_get ((int *)&object->ref_count);
3154 /* valid if last 2 refs are owned by this call to unref and the toggle_ref */
3155 gboolean has_toggle_ref = OBJECT_HAS_TOGGLE_REF (object);
3157 if (!g_atomic_int_compare_and_exchange ((int *)&object->ref_count, old_ref, old_ref - 1))
3158 goto retry_atomic_decrement2;
3160 TRACE (GOBJECT_OBJECT_UNREF(object,G_TYPE_FROM_INSTANCE(object),old_ref));
3162 /* if we went from 2->1 we need to notify toggle refs if any */
3163 if (old_ref == 2 && has_toggle_ref) /* The last ref being held in this case is owned by the toggle_ref */
3164 toggle_refs_notify (object, TRUE);
3169 /* we are still in the process of taking away the last ref */
3170 g_datalist_id_set_data (&object->qdata, quark_closure_array, NULL);
3171 g_signal_handlers_destroy (object);
3172 g_datalist_id_set_data (&object->qdata, quark_weak_refs, NULL);
3174 /* decrement the last reference */
3175 old_ref = g_atomic_int_add (&object->ref_count, -1);
3177 TRACE (GOBJECT_OBJECT_UNREF(object,G_TYPE_FROM_INSTANCE(object),old_ref));
3179 /* may have been re-referenced meanwhile */
3180 if (G_LIKELY (old_ref == 1))
3182 TRACE (GOBJECT_OBJECT_FINALIZE(object,G_TYPE_FROM_INSTANCE(object)));
3183 G_OBJECT_GET_CLASS (object)->finalize (object);
3185 TRACE (GOBJECT_OBJECT_FINALIZE_END(object,G_TYPE_FROM_INSTANCE(object)));
3187 #ifdef G_ENABLE_DEBUG
3190 /* catch objects not chaining finalize handlers */
3191 G_LOCK (debug_objects);
3192 g_assert (g_hash_table_lookup (debug_objects_ht, object) == NULL);
3193 G_UNLOCK (debug_objects);
3195 #endif /* G_ENABLE_DEBUG */
3196 g_type_free_instance ((GTypeInstance*) object);
3202 * g_clear_object: (skip)
3203 * @object_ptr: a pointer to a #GObject reference
3205 * Clears a reference to a #GObject.
3207 * @object_ptr must not be %NULL.
3209 * If the reference is %NULL then this function does nothing.
3210 * Otherwise, the reference count of the object is decreased and the
3211 * pointer is set to %NULL.
3213 * This function is threadsafe and modifies the pointer atomically,
3214 * using memory barriers where needed.
3216 * A macro is also included that allows this function to be used without
3221 #undef g_clear_object
3223 g_clear_object (volatile GObject **object_ptr)
3225 g_clear_pointer (object_ptr, g_object_unref);
3229 * g_object_get_qdata:
3230 * @object: The GObject to get a stored user data pointer from
3231 * @quark: A #GQuark, naming the user data pointer
3233 * This function gets back user data pointers stored via
3234 * g_object_set_qdata().
3236 * Returns: (transfer none): The user data pointer set, or %NULL
3239 g_object_get_qdata (GObject *object,
3242 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3244 return quark ? g_datalist_id_get_data (&object->qdata, quark) : NULL;
3248 * g_object_set_qdata: (skip)
3249 * @object: The GObject to set store a user data pointer
3250 * @quark: A #GQuark, naming the user data pointer
3251 * @data: An opaque user data pointer
3253 * This sets an opaque, named pointer on an object.
3254 * The name is specified through a #GQuark (retrived e.g. via
3255 * g_quark_from_static_string()), and the pointer
3256 * can be gotten back from the @object with g_object_get_qdata()
3257 * until the @object is finalized.
3258 * Setting a previously set user data pointer, overrides (frees)
3259 * the old pointer set, using #NULL as pointer essentially
3260 * removes the data stored.
3263 g_object_set_qdata (GObject *object,
3267 g_return_if_fail (G_IS_OBJECT (object));
3268 g_return_if_fail (quark > 0);
3270 g_datalist_id_set_data (&object->qdata, quark, data);
3274 * g_object_dup_qdata:
3275 * @object: the #GObject to store user data on
3276 * @quark: a #GQuark, naming the user data pointer
3277 * @dup_func: (allow-none): function to dup the value
3278 * @user_data: (allow-none): passed as user_data to @dup_func
3280 * This is a variant of g_object_get_qdata() which returns
3281 * a 'duplicate' of the value. @dup_func defines the
3282 * meaning of 'duplicate' in this context, it could e.g.
3283 * take a reference on a ref-counted object.
3285 * If the @quark is not set on the object then @dup_func
3286 * will be called with a %NULL argument.
3288 * Note that @dup_func is called while user data of @object
3291 * This function can be useful to avoid races when multiple
3292 * threads are using object data on the same key on the same
3295 * Returns: the result of calling @dup_func on the value
3296 * associated with @quark on @object, or %NULL if not set.
3297 * If @dup_func is %NULL, the value is returned
3303 g_object_dup_qdata (GObject *object,
3305 GDuplicateFunc dup_func,
3308 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3309 g_return_val_if_fail (quark > 0, NULL);
3311 return g_datalist_id_dup_data (&object->qdata, quark, dup_func, user_data);
3315 * g_object_replace_qdata:
3316 * @object: the #GObject to store user data on
3317 * @quark: a #GQuark, naming the user data pointer
3318 * @oldval: (allow-none): the old value to compare against
3319 * @newval: (allow-none): the new value
3320 * @destroy: (allow-none): a destroy notify for the new value
3321 * @old_destroy: (allow-none): destroy notify for the existing value
3323 * Compares the user data for the key @quark on @object with
3324 * @oldval, and if they are the same, replaces @oldval with
3327 * This is like a typical atomic compare-and-exchange
3328 * operation, for user data on an object.
3330 * If the previous value was replaced then ownership of the
3331 * old value (@oldval) is passed to the caller, including
3332 * the registered destroy notify for it (passed out in @old_destroy).
3333 * Its up to the caller to free this as he wishes, which may
3334 * or may not include using @old_destroy as sometimes replacement
3335 * should not destroy the object in the normal way.
3337 * Return: %TRUE if the existing value for @quark was replaced
3338 * by @newval, %FALSE otherwise.
3343 g_object_replace_qdata (GObject *object,
3347 GDestroyNotify destroy,
3348 GDestroyNotify *old_destroy)
3350 g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
3351 g_return_val_if_fail (quark > 0, FALSE);
3353 return g_datalist_id_replace_data (&object->qdata, quark,
3354 oldval, newval, destroy,
3359 * g_object_set_qdata_full: (skip)
3360 * @object: The GObject to set store a user data pointer
3361 * @quark: A #GQuark, naming the user data pointer
3362 * @data: An opaque user data pointer
3363 * @destroy: Function to invoke with @data as argument, when @data
3366 * This function works like g_object_set_qdata(), but in addition,
3367 * a void (*destroy) (gpointer) function may be specified which is
3368 * called with @data as argument when the @object is finalized, or
3369 * the data is being overwritten by a call to g_object_set_qdata()
3370 * with the same @quark.
3373 g_object_set_qdata_full (GObject *object,
3376 GDestroyNotify destroy)
3378 g_return_if_fail (G_IS_OBJECT (object));
3379 g_return_if_fail (quark > 0);
3381 g_datalist_id_set_data_full (&object->qdata, quark, data,
3382 data ? destroy : (GDestroyNotify) NULL);
3386 * g_object_steal_qdata:
3387 * @object: The GObject to get a stored user data pointer from
3388 * @quark: A #GQuark, naming the user data pointer
3390 * This function gets back user data pointers stored via
3391 * g_object_set_qdata() and removes the @data from object
3392 * without invoking its destroy() function (if any was
3394 * Usually, calling this function is only required to update
3395 * user data pointers with a destroy notifier, for example:
3398 * object_add_to_user_list (GObject *object,
3399 * const gchar *new_string)
3401 * // the quark, naming the object data
3402 * GQuark quark_string_list = g_quark_from_static_string ("my-string-list");
3403 * // retrive the old string list
3404 * GList *list = g_object_steal_qdata (object, quark_string_list);
3406 * // prepend new string
3407 * list = g_list_prepend (list, g_strdup (new_string));
3408 * // this changed 'list', so we need to set it again
3409 * g_object_set_qdata_full (object, quark_string_list, list, free_string_list);
3412 * free_string_list (gpointer data)
3414 * GList *node, *list = data;
3416 * for (node = list; node; node = node->next)
3417 * g_free (node->data);
3418 * g_list_free (list);
3421 * Using g_object_get_qdata() in the above example, instead of
3422 * g_object_steal_qdata() would have left the destroy function set,
3423 * and thus the partial string list would have been freed upon
3424 * g_object_set_qdata_full().
3426 * Returns: (transfer full): The user data pointer set, or %NULL
3429 g_object_steal_qdata (GObject *object,
3432 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3433 g_return_val_if_fail (quark > 0, NULL);
3435 return g_datalist_id_remove_no_notify (&object->qdata, quark);
3439 * g_object_get_data:
3440 * @object: #GObject containing the associations
3441 * @key: name of the key for that association
3443 * Gets a named field from the objects table of associations (see g_object_set_data()).
3445 * Returns: (transfer none): the data if found, or %NULL if no such data exists.
3448 g_object_get_data (GObject *object,
3451 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3452 g_return_val_if_fail (key != NULL, NULL);
3454 return g_datalist_get_data (&object->qdata, key);
3458 * g_object_set_data:
3459 * @object: #GObject containing the associations.
3460 * @key: name of the key
3461 * @data: data to associate with that key
3463 * Each object carries around a table of associations from
3464 * strings to pointers. This function lets you set an association.
3466 * If the object already had an association with that name,
3467 * the old association will be destroyed.
3470 g_object_set_data (GObject *object,
3474 g_return_if_fail (G_IS_OBJECT (object));
3475 g_return_if_fail (key != NULL);
3477 g_datalist_id_set_data (&object->qdata, g_quark_from_string (key), data);
3481 * g_object_dup_data:
3482 * @object: the #GObject to store user data on
3483 * @key: a string, naming the user data pointer
3484 * @dup_func: (allow-none): function to dup the value
3485 * @user_data: (allow-none): passed as user_data to @dup_func
3487 * This is a variant of g_object_get_data() which returns
3488 * a 'duplicate' of the value. @dup_func defines the
3489 * meaning of 'duplicate' in this context, it could e.g.
3490 * take a reference on a ref-counted object.
3492 * If the @key is not set on the object then @dup_func
3493 * will be called with a %NULL argument.
3495 * Note that @dup_func is called while user data of @object
3498 * This function can be useful to avoid races when multiple
3499 * threads are using object data on the same key on the same
3502 * Returns: the result of calling @dup_func on the value
3503 * associated with @key on @object, or %NULL if not set.
3504 * If @dup_func is %NULL, the value is returned
3510 g_object_dup_data (GObject *object,
3512 GDuplicateFunc dup_func,
3515 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3516 g_return_val_if_fail (key != NULL, NULL);
3518 return g_datalist_id_dup_data (&object->qdata,
3519 g_quark_from_string (key),
3520 dup_func, user_data);
3524 * g_object_replace_data:
3525 * @object: the #GObject to store user data on
3526 * @key: a string, naming the user data pointer
3527 * @oldval: (allow-none): the old value to compare against
3528 * @newval: (allow-none): the new value
3529 * @destroy: (allow-none): a destroy notify for the new value
3530 * @old_destroy: (allow-none): destroy notify for the existing value
3532 * Compares the user data for the key @key on @object with
3533 * @oldval, and if they are the same, replaces @oldval with
3536 * This is like a typical atomic compare-and-exchange
3537 * operation, for user data on an object.
3539 * If the previous value was replaced then ownership of the
3540 * old value (@oldval) is passed to the caller, including
3541 * the registered destroy notify for it (passed out in @old_destroy).
3542 * Its up to the caller to free this as he wishes, which may
3543 * or may not include using @old_destroy as sometimes replacement
3544 * should not destroy the object in the normal way.
3546 * Return: %TRUE if the existing value for @key was replaced
3547 * by @newval, %FALSE otherwise.
3552 g_object_replace_data (GObject *object,
3556 GDestroyNotify destroy,
3557 GDestroyNotify *old_destroy)
3559 g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
3560 g_return_val_if_fail (key != NULL, FALSE);
3562 return g_datalist_id_replace_data (&object->qdata,
3563 g_quark_from_string (key),
3564 oldval, newval, destroy,
3569 * g_object_set_data_full: (skip)
3570 * @object: #GObject containing the associations
3571 * @key: name of the key
3572 * @data: data to associate with that key
3573 * @destroy: function to call when the association is destroyed
3575 * Like g_object_set_data() except it adds notification
3576 * for when the association is destroyed, either by setting it
3577 * to a different value or when the object is destroyed.
3579 * Note that the @destroy callback is not called if @data is %NULL.
3582 g_object_set_data_full (GObject *object,
3585 GDestroyNotify destroy)
3587 g_return_if_fail (G_IS_OBJECT (object));
3588 g_return_if_fail (key != NULL);
3590 g_datalist_id_set_data_full (&object->qdata, g_quark_from_string (key), data,
3591 data ? destroy : (GDestroyNotify) NULL);
3595 * g_object_steal_data:
3596 * @object: #GObject containing the associations
3597 * @key: name of the key
3599 * Remove a specified datum from the object's data associations,
3600 * without invoking the association's destroy handler.
3602 * Returns: (transfer full): the data if found, or %NULL if no such data exists.
3605 g_object_steal_data (GObject *object,
3610 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3611 g_return_val_if_fail (key != NULL, NULL);
3613 quark = g_quark_try_string (key);
3615 return quark ? g_datalist_id_remove_no_notify (&object->qdata, quark) : NULL;
3619 g_value_object_init (GValue *value)
3621 value->data[0].v_pointer = NULL;
3625 g_value_object_free_value (GValue *value)
3627 if (value->data[0].v_pointer)
3628 g_object_unref (value->data[0].v_pointer);
3632 g_value_object_copy_value (const GValue *src_value,
3635 if (src_value->data[0].v_pointer)
3636 dest_value->data[0].v_pointer = g_object_ref (src_value->data[0].v_pointer);
3638 dest_value->data[0].v_pointer = NULL;
3642 g_value_object_transform_value (const GValue *src_value,
3645 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)))
3646 dest_value->data[0].v_pointer = g_object_ref (src_value->data[0].v_pointer);
3648 dest_value->data[0].v_pointer = NULL;
3652 g_value_object_peek_pointer (const GValue *value)
3654 return value->data[0].v_pointer;
3658 g_value_object_collect_value (GValue *value,
3659 guint n_collect_values,
3660 GTypeCValue *collect_values,
3661 guint collect_flags)
3663 if (collect_values[0].v_pointer)
3665 GObject *object = collect_values[0].v_pointer;
3667 if (object->g_type_instance.g_class == NULL)
3668 return g_strconcat ("invalid unclassed object pointer for value type '",
3669 G_VALUE_TYPE_NAME (value),
3672 else if (!g_value_type_compatible (G_OBJECT_TYPE (object), G_VALUE_TYPE (value)))
3673 return g_strconcat ("invalid object type '",
3674 G_OBJECT_TYPE_NAME (object),
3675 "' for value type '",
3676 G_VALUE_TYPE_NAME (value),
3679 /* never honour G_VALUE_NOCOPY_CONTENTS for ref-counted types */
3680 value->data[0].v_pointer = g_object_ref (object);
3683 value->data[0].v_pointer = NULL;
3689 g_value_object_lcopy_value (const GValue *value,
3690 guint n_collect_values,
3691 GTypeCValue *collect_values,
3692 guint collect_flags)
3694 GObject **object_p = collect_values[0].v_pointer;
3697 return g_strdup_printf ("value location for '%s' passed as NULL", G_VALUE_TYPE_NAME (value));
3699 if (!value->data[0].v_pointer)
3701 else if (collect_flags & G_VALUE_NOCOPY_CONTENTS)
3702 *object_p = value->data[0].v_pointer;
3704 *object_p = g_object_ref (value->data[0].v_pointer);
3710 * g_value_set_object:
3711 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
3712 * @v_object: (type GObject.Object) (allow-none): object value to be set
3714 * Set the contents of a %G_TYPE_OBJECT derived #GValue to @v_object.
3716 * g_value_set_object() increases the reference count of @v_object
3717 * (the #GValue holds a reference to @v_object). If you do not wish
3718 * to increase the reference count of the object (i.e. you wish to
3719 * pass your current reference to the #GValue because you no longer
3720 * need it), use g_value_take_object() instead.
3722 * It is important that your #GValue holds a reference to @v_object (either its
3723 * own, or one it has taken) to ensure that the object won't be destroyed while
3724 * the #GValue still exists).
3727 g_value_set_object (GValue *value,
3732 g_return_if_fail (G_VALUE_HOLDS_OBJECT (value));
3734 old = value->data[0].v_pointer;
3738 g_return_if_fail (G_IS_OBJECT (v_object));
3739 g_return_if_fail (g_value_type_compatible (G_OBJECT_TYPE (v_object), G_VALUE_TYPE (value)));
3741 value->data[0].v_pointer = v_object;
3742 g_object_ref (value->data[0].v_pointer);
3745 value->data[0].v_pointer = NULL;
3748 g_object_unref (old);
3752 * g_value_set_object_take_ownership: (skip)
3753 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
3754 * @v_object: (allow-none): object value to be set
3756 * This is an internal function introduced mainly for C marshallers.
3758 * Deprecated: 2.4: Use g_value_take_object() instead.
3761 g_value_set_object_take_ownership (GValue *value,
3764 g_value_take_object (value, v_object);
3768 * g_value_take_object: (skip)
3769 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
3770 * @v_object: (allow-none): object value to be set
3772 * Sets the contents of a %G_TYPE_OBJECT derived #GValue to @v_object
3773 * and takes over the ownership of the callers reference to @v_object;
3774 * the caller doesn't have to unref it any more (i.e. the reference
3775 * count of the object is not increased).
3777 * If you want the #GValue to hold its own reference to @v_object, use
3778 * g_value_set_object() instead.
3783 g_value_take_object (GValue *value,
3786 g_return_if_fail (G_VALUE_HOLDS_OBJECT (value));
3788 if (value->data[0].v_pointer)
3790 g_object_unref (value->data[0].v_pointer);
3791 value->data[0].v_pointer = NULL;
3796 g_return_if_fail (G_IS_OBJECT (v_object));
3797 g_return_if_fail (g_value_type_compatible (G_OBJECT_TYPE (v_object), G_VALUE_TYPE (value)));
3799 value->data[0].v_pointer = v_object; /* we take over the reference count */
3804 * g_value_get_object:
3805 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
3807 * Get the contents of a %G_TYPE_OBJECT derived #GValue.
3809 * Returns: (type GObject.Object) (transfer none): object contents of @value
3812 g_value_get_object (const GValue *value)
3814 g_return_val_if_fail (G_VALUE_HOLDS_OBJECT (value), NULL);
3816 return value->data[0].v_pointer;
3820 * g_value_dup_object:
3821 * @value: a valid #GValue whose type is derived from %G_TYPE_OBJECT
3823 * Get the contents of a %G_TYPE_OBJECT derived #GValue, increasing
3824 * its reference count. If the contents of the #GValue are %NULL, then
3825 * %NULL will be returned.
3827 * Returns: (type GObject.Object) (transfer full): object content of @value,
3828 * should be unreferenced when no longer needed.
3831 g_value_dup_object (const GValue *value)
3833 g_return_val_if_fail (G_VALUE_HOLDS_OBJECT (value), NULL);
3835 return value->data[0].v_pointer ? g_object_ref (value->data[0].v_pointer) : NULL;
3839 * g_signal_connect_object: (skip)
3840 * @instance: the instance to connect to.
3841 * @detailed_signal: a string of the form "signal-name::detail".
3842 * @c_handler: the #GCallback to connect.
3843 * @gobject: the object to pass as data to @c_handler.
3844 * @connect_flags: a combination of #GConnectFlags.
3846 * This is similar to g_signal_connect_data(), but uses a closure which
3847 * ensures that the @gobject stays alive during the call to @c_handler
3848 * by temporarily adding a reference count to @gobject.
3850 * When the @gobject is destroyed the signal handler will be automatically
3851 * disconnected. Note that this is not currently threadsafe (ie:
3852 * emitting a signal while @gobject is being destroyed in another thread
3855 * Returns: the handler id.
3858 g_signal_connect_object (gpointer instance,
3859 const gchar *detailed_signal,
3860 GCallback c_handler,
3862 GConnectFlags connect_flags)
3864 g_return_val_if_fail (G_TYPE_CHECK_INSTANCE (instance), 0);
3865 g_return_val_if_fail (detailed_signal != NULL, 0);
3866 g_return_val_if_fail (c_handler != NULL, 0);
3872 g_return_val_if_fail (G_IS_OBJECT (gobject), 0);
3874 closure = ((connect_flags & G_CONNECT_SWAPPED) ? g_cclosure_new_object_swap : g_cclosure_new_object) (c_handler, gobject);
3876 return g_signal_connect_closure (instance, detailed_signal, closure, connect_flags & G_CONNECT_AFTER);
3879 return g_signal_connect_data (instance, detailed_signal, c_handler, NULL, NULL, connect_flags);
3885 GClosure *closures[1]; /* flexible array */
3887 /* don't change this structure without supplying an accessor for
3888 * watched closures, e.g.:
3889 * GSList* g_object_list_watched_closures (GObject *object)
3892 * g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3893 * carray = g_object_get_data (object, "GObject-closure-array");
3896 * GSList *slist = NULL;
3898 * for (i = 0; i < carray->n_closures; i++)
3899 * slist = g_slist_prepend (slist, carray->closures[i]);
3907 object_remove_closure (gpointer data,
3910 GObject *object = data;
3914 G_LOCK (closure_array_mutex);
3915 carray = g_object_get_qdata (object, quark_closure_array);
3916 for (i = 0; i < carray->n_closures; i++)
3917 if (carray->closures[i] == closure)
3919 carray->n_closures--;
3920 if (i < carray->n_closures)
3921 carray->closures[i] = carray->closures[carray->n_closures];
3922 G_UNLOCK (closure_array_mutex);
3925 G_UNLOCK (closure_array_mutex);
3926 g_assert_not_reached ();
3930 destroy_closure_array (gpointer data)
3932 CArray *carray = data;
3933 GObject *object = carray->object;
3934 guint i, n = carray->n_closures;
3936 for (i = 0; i < n; i++)
3938 GClosure *closure = carray->closures[i];
3940 /* removing object_remove_closure() upfront is probably faster than
3941 * letting it fiddle with quark_closure_array which is empty anyways
3943 g_closure_remove_invalidate_notifier (closure, object, object_remove_closure);
3944 g_closure_invalidate (closure);
3950 * g_object_watch_closure:
3951 * @object: GObject restricting lifetime of @closure
3952 * @closure: GClosure to watch
3954 * This function essentially limits the life time of the @closure to
3955 * the life time of the object. That is, when the object is finalized,
3956 * the @closure is invalidated by calling g_closure_invalidate() on
3957 * it, in order to prevent invocations of the closure with a finalized
3958 * (nonexisting) object. Also, g_object_ref() and g_object_unref() are
3959 * added as marshal guards to the @closure, to ensure that an extra
3960 * reference count is held on @object during invocation of the
3961 * @closure. Usually, this function will be called on closures that
3962 * use this @object as closure data.
3965 g_object_watch_closure (GObject *object,
3971 g_return_if_fail (G_IS_OBJECT (object));
3972 g_return_if_fail (closure != NULL);
3973 g_return_if_fail (closure->is_invalid == FALSE);
3974 g_return_if_fail (closure->in_marshal == FALSE);
3975 g_return_if_fail (object->ref_count > 0); /* this doesn't work on finalizing objects */
3977 g_closure_add_invalidate_notifier (closure, object, object_remove_closure);
3978 g_closure_add_marshal_guards (closure,
3979 object, (GClosureNotify) g_object_ref,
3980 object, (GClosureNotify) g_object_unref);
3981 G_LOCK (closure_array_mutex);
3982 carray = g_datalist_id_remove_no_notify (&object->qdata, quark_closure_array);
3985 carray = g_renew (CArray, NULL, 1);
3986 carray->object = object;
3987 carray->n_closures = 1;
3992 i = carray->n_closures++;
3993 carray = g_realloc (carray, sizeof (*carray) + sizeof (carray->closures[0]) * i);
3995 carray->closures[i] = closure;
3996 g_datalist_id_set_data_full (&object->qdata, quark_closure_array, carray, destroy_closure_array);
3997 G_UNLOCK (closure_array_mutex);
4001 * g_closure_new_object:
4002 * @sizeof_closure: the size of the structure to allocate, must be at least
4003 * <literal>sizeof (GClosure)</literal>
4004 * @object: a #GObject pointer to store in the @data field of the newly
4005 * allocated #GClosure
4007 * A variant of g_closure_new_simple() which stores @object in the
4008 * @data field of the closure and calls g_object_watch_closure() on
4009 * @object and the created closure. This function is mainly useful
4010 * when implementing new types of closures.
4012 * Returns: (transfer full): a newly allocated #GClosure
4015 g_closure_new_object (guint sizeof_closure,
4020 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
4021 g_return_val_if_fail (object->ref_count > 0, NULL); /* this doesn't work on finalizing objects */
4023 closure = g_closure_new_simple (sizeof_closure, object);
4024 g_object_watch_closure (object, closure);
4030 * g_cclosure_new_object: (skip)
4031 * @callback_func: the function to invoke
4032 * @object: a #GObject pointer to pass to @callback_func
4034 * A variant of g_cclosure_new() which uses @object as @user_data and
4035 * calls g_object_watch_closure() on @object and the created
4036 * closure. This function is useful when you have a callback closely
4037 * associated with a #GObject, and want the callback to no longer run
4038 * after the object is is freed.
4040 * Returns: a new #GCClosure
4043 g_cclosure_new_object (GCallback callback_func,
4048 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
4049 g_return_val_if_fail (object->ref_count > 0, NULL); /* this doesn't work on finalizing objects */
4050 g_return_val_if_fail (callback_func != NULL, NULL);
4052 closure = g_cclosure_new (callback_func, object, NULL);
4053 g_object_watch_closure (object, closure);
4059 * g_cclosure_new_object_swap: (skip)
4060 * @callback_func: the function to invoke
4061 * @object: a #GObject pointer to pass to @callback_func
4063 * A variant of g_cclosure_new_swap() which uses @object as @user_data
4064 * and calls g_object_watch_closure() on @object and the created
4065 * closure. This function is useful when you have a callback closely
4066 * associated with a #GObject, and want the callback to no longer run
4067 * after the object is is freed.
4069 * Returns: a new #GCClosure
4072 g_cclosure_new_object_swap (GCallback callback_func,
4077 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
4078 g_return_val_if_fail (object->ref_count > 0, NULL); /* this doesn't work on finalizing objects */
4079 g_return_val_if_fail (callback_func != NULL, NULL);
4081 closure = g_cclosure_new_swap (callback_func, object, NULL);
4082 g_object_watch_closure (object, closure);
4088 g_object_compat_control (gsize what,
4094 case 1: /* floating base type */
4095 return G_TYPE_INITIALLY_UNOWNED;
4096 case 2: /* FIXME: remove this once GLib/Gtk+ break ABI again */
4097 floating_flag_handler = (guint(*)(GObject*,gint)) data;
4099 case 3: /* FIXME: remove this once GLib/Gtk+ break ABI again */
4101 *pp = floating_flag_handler;
4108 G_DEFINE_TYPE (GInitiallyUnowned, g_initially_unowned, G_TYPE_OBJECT);
4111 g_initially_unowned_init (GInitiallyUnowned *object)
4113 g_object_force_floating (object);
4117 g_initially_unowned_class_init (GInitiallyUnownedClass *klass)
4124 * A structure containing a weak reference to a #GObject. It can either
4125 * be empty (i.e. point to %NULL), or point to an object for as long as
4126 * at least one "strong" reference to that object exists. Before the
4127 * object's #GObjectClass.dispose method is called, every #GWeakRef
4128 * associated with becomes empty (i.e. points to %NULL).
4130 * Like #GValue, #GWeakRef can be statically allocated, stack- or
4131 * heap-allocated, or embedded in larger structures.
4133 * Unlike g_object_weak_ref() and g_object_add_weak_pointer(), this weak
4134 * reference is thread-safe: converting a weak pointer to a reference is
4135 * atomic with respect to invalidation of weak pointers to destroyed
4138 * If the object's #GObjectClass.dispose method results in additional
4139 * references to the object being held, any #GWeakRef<!-- -->s taken
4140 * before it was disposed will continue to point to %NULL. If
4141 * #GWeakRef<!-- -->s are taken after the object is disposed and
4142 * re-referenced, they will continue to point to it until its refcount
4143 * goes back to zero, at which point they too will be invalidated.
4147 * g_weak_ref_init: (skip)
4148 * @weak_ref: (inout): uninitialized or empty location for a weak
4150 * @object: (allow-none): a #GObject or %NULL
4152 * Initialise a non-statically-allocated #GWeakRef.
4154 * This function also calls g_weak_ref_set() with @object on the
4155 * freshly-initialised weak reference.
4157 * This function should always be matched with a call to
4158 * g_weak_ref_clear(). It is not necessary to use this function for a
4159 * #GWeakRef in static storage because it will already be
4160 * properly initialised. Just use g_weak_ref_set() directly.
4165 g_weak_ref_init (GWeakRef *weak_ref,
4168 weak_ref->priv.p = NULL;
4170 g_weak_ref_set (weak_ref, object);
4174 * g_weak_ref_clear: (skip)
4175 * @weak_ref: (inout): location of a weak reference, which
4178 * Frees resources associated with a non-statically-allocated #GWeakRef.
4179 * After this call, the #GWeakRef is left in an undefined state.
4181 * You should only call this on a #GWeakRef that previously had
4182 * g_weak_ref_init() called on it.
4187 g_weak_ref_clear (GWeakRef *weak_ref)
4189 g_weak_ref_set (weak_ref, NULL);
4192 weak_ref->priv.p = (void *) 0xccccccccu;
4196 * g_weak_ref_get: (skip)
4197 * @weak_ref: (inout): location of a weak reference to a #GObject
4199 * If @weak_ref is not empty, atomically acquire a strong
4200 * reference to the object it points to, and return that reference.
4202 * This function is needed because of the potential race between taking
4203 * the pointer value and g_object_ref() on it, if the object was losing
4204 * its last reference at the same time in a different thread.
4206 * The caller should release the resulting reference in the usual way,
4207 * by using g_object_unref().
4209 * Returns: (transfer full) (type GObject.Object): the object pointed to
4210 * by @weak_ref, or %NULL if it was empty
4215 g_weak_ref_get (GWeakRef *weak_ref)
4217 gpointer object_or_null;
4219 g_return_val_if_fail (weak_ref!= NULL, NULL);
4221 g_rw_lock_reader_lock (&weak_locations_lock);
4223 object_or_null = weak_ref->priv.p;
4225 if (object_or_null != NULL)
4226 g_object_ref (object_or_null);
4228 g_rw_lock_reader_unlock (&weak_locations_lock);
4230 return object_or_null;
4234 * g_weak_ref_set: (skip)
4235 * @weak_ref: location for a weak reference
4236 * @object: (allow-none): a #GObject or %NULL
4238 * Change the object to which @weak_ref points, or set it to
4241 * You must own a strong reference on @object while calling this
4247 g_weak_ref_set (GWeakRef *weak_ref,
4250 GSList **weak_locations;
4251 GObject *new_object;
4252 GObject *old_object;
4254 g_return_if_fail (weak_ref != NULL);
4255 g_return_if_fail (object == NULL || G_IS_OBJECT (object));
4257 new_object = object;
4259 g_rw_lock_writer_lock (&weak_locations_lock);
4261 /* We use the extra level of indirection here so that if we have ever
4262 * had a weak pointer installed at any point in time on this object,
4263 * we can see that there is a non-NULL value associated with the
4264 * weak-pointer quark and know that this value will not change at any
4265 * point in the object's lifetime.
4267 * Both properties are important for reducing the amount of times we
4268 * need to acquire locks and for decreasing the duration of time the
4269 * lock is held while avoiding some rather tricky races.
4271 * Specifically: we can avoid having to do an extra unconditional lock
4272 * in g_object_unref() without worrying about some extremely tricky
4276 old_object = weak_ref->priv.p;
4277 if (new_object != old_object)
4279 weak_ref->priv.p = new_object;
4281 /* Remove the weak ref from the old object */
4282 if (old_object != NULL)
4284 weak_locations = g_datalist_id_get_data (&old_object->qdata, quark_weak_locations);
4285 /* for it to point to an object, the object must have had it added once */
4286 g_assert (weak_locations != NULL);
4288 *weak_locations = g_slist_remove (*weak_locations, weak_ref);
4291 /* Add the weak ref to the new object */
4292 if (new_object != NULL)
4294 weak_locations = g_datalist_id_get_data (&new_object->qdata, quark_weak_locations);
4296 if (weak_locations == NULL)
4298 weak_locations = g_new0 (GSList *, 1);
4299 g_datalist_id_set_data_full (&new_object->qdata, quark_weak_locations, weak_locations, g_free);
4302 *weak_locations = g_slist_prepend (*weak_locations, weak_ref);
4306 g_rw_lock_writer_unlock (&weak_locations_lock);