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"
39 * @short_description: The base object type
40 * @see_also: #GParamSpecObject, g_param_spec_object()
41 * @title: The Base Object Type
43 * GObject is the fundamental type providing the common attributes and
44 * methods for all object types in GTK+, Pango and other libraries
45 * based on GObject. The GObject class provides methods for object
46 * construction and destruction, property access methods, and signal
47 * support. Signals are described in detail in <xref
48 * linkend="gobject-Signals"/>.
50 * <para id="floating-ref">
51 * GInitiallyUnowned is derived from GObject. The only difference between
52 * the two is that the initial reference of a GInitiallyUnowned is flagged
53 * as a <firstterm>floating</firstterm> reference.
54 * This means that it is not specifically claimed to be "owned" by
55 * any code portion. The main motivation for providing floating references is
56 * C convenience. In particular, it allows code to be written as:
58 * container = create_container ();
59 * container_add_child (container, create_child());
61 * If <function>container_add_child()</function> will g_object_ref_sink() the
62 * passed in child, no reference of the newly created child is leaked.
63 * Without floating references, <function>container_add_child()</function>
64 * can only g_object_ref() the new child, so to implement this code without
65 * reference leaks, it would have to be written as:
68 * container = create_container ();
69 * child = create_child ();
70 * container_add_child (container, child);
71 * g_object_unref (child);
73 * The floating reference can be converted into
74 * an ordinary reference by calling g_object_ref_sink().
75 * For already sunken objects (objects that don't have a floating reference
76 * anymore), g_object_ref_sink() is equivalent to g_object_ref() and returns
78 * Since floating references are useful almost exclusively for C convenience,
79 * language bindings that provide automated reference and memory ownership
80 * maintenance (such as smart pointers or garbage collection) should not
81 * expose floating references in their API.
84 * Some object implementations may need to save an objects floating state
85 * across certain code portions (an example is #GtkMenu), to achieve this,
86 * the following sequence can be used:
89 * /* save floating state */
90 * gboolean was_floating = g_object_is_floating (object);
91 * g_object_ref_sink (object);
92 * /* protected code portion */
94 * /* restore floating state */
96 * g_object_force_floating (object);
97 * g_object_unref (object); /* release previously acquired reference */
103 #define PARAM_SPEC_PARAM_ID(pspec) ((pspec)->param_id)
104 #define PARAM_SPEC_SET_PARAM_ID(pspec, id) ((pspec)->param_id = (id))
106 #define OBJECT_HAS_TOGGLE_REF_FLAG 0x1
107 #define OBJECT_HAS_TOGGLE_REF(object) \
108 ((g_datalist_get_flags (&(object)->qdata) & OBJECT_HAS_TOGGLE_REF_FLAG) != 0)
109 #define OBJECT_FLOATING_FLAG 0x2
111 #define CLASS_HAS_PROPS_FLAG 0x1
112 #define CLASS_HAS_PROPS(class) \
113 ((class)->flags & CLASS_HAS_PROPS_FLAG)
114 #define CLASS_HAS_CUSTOM_CONSTRUCTOR(class) \
115 ((class)->constructor != g_object_constructor)
116 #define CLASS_HAS_CUSTOM_CONSTRUCTED(class) \
117 ((class)->constructed != g_object_constructed)
119 #define CLASS_HAS_DERIVED_CLASS_FLAG 0x2
120 #define CLASS_HAS_DERIVED_CLASS(class) \
121 ((class)->flags & CLASS_HAS_DERIVED_CLASS_FLAG)
123 /* --- signals --- */
130 /* --- properties --- */
136 /* --- prototypes --- */
137 static void g_object_base_class_init (GObjectClass *class);
138 static void g_object_base_class_finalize (GObjectClass *class);
139 static void g_object_do_class_init (GObjectClass *class);
140 static void g_object_init (GObject *object,
141 GObjectClass *class);
142 static GObject* g_object_constructor (GType type,
143 guint n_construct_properties,
144 GObjectConstructParam *construct_params);
145 static void g_object_constructed (GObject *object);
146 static void g_object_real_dispose (GObject *object);
147 static void g_object_finalize (GObject *object);
148 static void g_object_do_set_property (GObject *object,
152 static void g_object_do_get_property (GObject *object,
156 static void g_value_object_init (GValue *value);
157 static void g_value_object_free_value (GValue *value);
158 static void g_value_object_copy_value (const GValue *src_value,
160 static void g_value_object_transform_value (const GValue *src_value,
162 static gpointer g_value_object_peek_pointer (const GValue *value);
163 static gchar* g_value_object_collect_value (GValue *value,
164 guint n_collect_values,
165 GTypeCValue *collect_values,
166 guint collect_flags);
167 static gchar* g_value_object_lcopy_value (const GValue *value,
168 guint n_collect_values,
169 GTypeCValue *collect_values,
170 guint collect_flags);
171 static void g_object_dispatch_properties_changed (GObject *object,
173 GParamSpec **pspecs);
174 static guint object_floating_flag_handler (GObject *object,
177 static void object_interface_check_properties (gpointer func_data,
180 /* --- typedefs --- */
181 typedef struct _GObjectNotifyQueue GObjectNotifyQueue;
183 struct _GObjectNotifyQueue
187 guint16 freeze_count;
190 /* --- variables --- */
191 G_LOCK_DEFINE_STATIC (closure_array_mutex);
192 G_LOCK_DEFINE_STATIC (weak_refs_mutex);
193 G_LOCK_DEFINE_STATIC (toggle_refs_mutex);
194 static GQuark quark_closure_array = 0;
195 static GQuark quark_weak_refs = 0;
196 static GQuark quark_toggle_refs = 0;
197 static GQuark quark_notify_queue;
198 static GParamSpecPool *pspec_pool = NULL;
199 static gulong gobject_signals[LAST_SIGNAL] = { 0, };
200 static guint (*floating_flag_handler) (GObject*, gint) = object_floating_flag_handler;
201 G_LOCK_DEFINE_STATIC (construction_mutex);
202 static GSList *construction_objects = NULL;
204 /* --- functions --- */
205 #ifdef G_ENABLE_DEBUG
206 #define IF_DEBUG(debug_type) if (_g_type_debug_flags & G_TYPE_DEBUG_ ## debug_type)
207 G_LOCK_DEFINE_STATIC (debug_objects);
208 static volatile GObject *g_trap_object_ref = NULL;
209 static guint debug_objects_count = 0;
210 static GHashTable *debug_objects_ht = NULL;
212 G_LOCK_DEFINE_STATIC(notify_lock);
214 /* --- functions --- */
216 g_object_notify_queue_free (gpointer data)
218 GObjectNotifyQueue *nqueue = data;
220 g_slist_free (nqueue->pspecs);
221 g_slice_free (GObjectNotifyQueue, nqueue);
224 static GObjectNotifyQueue*
225 g_object_notify_queue_freeze (GObject *object,
226 gboolean conditional)
228 GObjectNotifyQueue *nqueue;
231 nqueue = g_datalist_id_get_data (&object->qdata, quark_notify_queue);
236 G_UNLOCK(notify_lock);
240 nqueue = g_slice_new0 (GObjectNotifyQueue);
241 g_datalist_id_set_data_full (&object->qdata, quark_notify_queue,
242 nqueue, g_object_notify_queue_free);
245 if (nqueue->freeze_count >= 65535)
246 g_critical("Free queue for %s (%p) is larger than 65535,"
247 " called g_object_freeze_notify() too often."
248 " Forgot to call g_object_thaw_notify() or infinite loop",
249 G_OBJECT_TYPE_NAME (object), object);
251 nqueue->freeze_count++;
252 G_UNLOCK(notify_lock);
258 g_object_notify_queue_thaw (GObject *object,
259 GObjectNotifyQueue *nqueue)
261 GParamSpec *pspecs_mem[16], **pspecs, **free_me = NULL;
265 g_return_if_fail (nqueue->freeze_count > 0);
266 g_return_if_fail (g_atomic_int_get(&object->ref_count) > 0);
270 /* Just make sure we never get into some nasty race condition */
271 if (G_UNLIKELY(nqueue->freeze_count == 0)) {
272 G_UNLOCK(notify_lock);
273 g_warning ("%s: property-changed notification for %s(%p) is not frozen",
274 G_STRFUNC, G_OBJECT_TYPE_NAME (object), object);
278 nqueue->freeze_count--;
279 if (nqueue->freeze_count) {
280 G_UNLOCK(notify_lock);
284 pspecs = nqueue->n_pspecs > 16 ? free_me = g_new (GParamSpec*, nqueue->n_pspecs) : pspecs_mem;
286 for (slist = nqueue->pspecs; slist; slist = slist->next)
288 pspecs[n_pspecs++] = slist->data;
290 g_datalist_id_set_data (&object->qdata, quark_notify_queue, NULL);
292 G_UNLOCK(notify_lock);
295 G_OBJECT_GET_CLASS (object)->dispatch_properties_changed (object, n_pspecs, pspecs);
300 g_object_notify_queue_add (GObject *object,
301 GObjectNotifyQueue *nqueue,
306 g_return_if_fail (nqueue->n_pspecs < 65535);
308 if (g_slist_find (nqueue->pspecs, pspec) == NULL)
310 nqueue->pspecs = g_slist_prepend (nqueue->pspecs, pspec);
314 G_UNLOCK(notify_lock);
318 debug_objects_foreach (gpointer key,
322 GObject *object = value;
324 g_message ("[%p] stale %s\tref_count=%u",
326 G_OBJECT_TYPE_NAME (object),
331 debug_objects_atexit (void)
335 G_LOCK (debug_objects);
336 g_message ("stale GObjects: %u", debug_objects_count);
337 g_hash_table_foreach (debug_objects_ht, debug_objects_foreach, NULL);
338 G_UNLOCK (debug_objects);
341 #endif /* G_ENABLE_DEBUG */
344 _g_object_type_init (void)
346 static gboolean initialized = FALSE;
347 static const GTypeFundamentalInfo finfo = {
348 G_TYPE_FLAG_CLASSED | G_TYPE_FLAG_INSTANTIATABLE | G_TYPE_FLAG_DERIVABLE | G_TYPE_FLAG_DEEP_DERIVABLE,
350 static GTypeInfo info = {
351 sizeof (GObjectClass),
352 (GBaseInitFunc) g_object_base_class_init,
353 (GBaseFinalizeFunc) g_object_base_class_finalize,
354 (GClassInitFunc) g_object_do_class_init,
355 NULL /* class_destroy */,
356 NULL /* class_data */,
359 (GInstanceInitFunc) g_object_init,
360 NULL, /* value_table */
362 static const GTypeValueTable value_table = {
363 g_value_object_init, /* value_init */
364 g_value_object_free_value, /* value_free */
365 g_value_object_copy_value, /* value_copy */
366 g_value_object_peek_pointer, /* value_peek_pointer */
367 "p", /* collect_format */
368 g_value_object_collect_value, /* collect_value */
369 "p", /* lcopy_format */
370 g_value_object_lcopy_value, /* lcopy_value */
374 g_return_if_fail (initialized == FALSE);
379 info.value_table = &value_table;
380 type = g_type_register_fundamental (G_TYPE_OBJECT, g_intern_static_string ("GObject"), &info, &finfo, 0);
381 g_assert (type == G_TYPE_OBJECT);
382 g_value_register_transform_func (G_TYPE_OBJECT, G_TYPE_OBJECT, g_value_object_transform_value);
384 #ifdef G_ENABLE_DEBUG
387 debug_objects_ht = g_hash_table_new (g_direct_hash, NULL);
388 g_atexit (debug_objects_atexit);
390 #endif /* G_ENABLE_DEBUG */
394 g_object_base_class_init (GObjectClass *class)
396 GObjectClass *pclass = g_type_class_peek_parent (class);
398 /* Don't inherit HAS_DERIVED_CLASS flag from parent class */
399 class->flags &= ~CLASS_HAS_DERIVED_CLASS_FLAG;
402 pclass->flags |= CLASS_HAS_DERIVED_CLASS_FLAG;
404 /* reset instance specific fields and methods that don't get inherited */
405 class->construct_properties = pclass ? g_slist_copy (pclass->construct_properties) : NULL;
406 class->get_property = NULL;
407 class->set_property = NULL;
411 g_object_base_class_finalize (GObjectClass *class)
415 _g_signals_destroy (G_OBJECT_CLASS_TYPE (class));
417 g_slist_free (class->construct_properties);
418 class->construct_properties = NULL;
419 list = g_param_spec_pool_list_owned (pspec_pool, G_OBJECT_CLASS_TYPE (class));
420 for (node = list; node; node = node->next)
422 GParamSpec *pspec = node->data;
424 g_param_spec_pool_remove (pspec_pool, pspec);
425 PARAM_SPEC_SET_PARAM_ID (pspec, 0);
426 g_param_spec_unref (pspec);
432 g_object_do_class_init (GObjectClass *class)
434 /* read the comment about typedef struct CArray; on why not to change this quark */
435 quark_closure_array = g_quark_from_static_string ("GObject-closure-array");
437 quark_weak_refs = g_quark_from_static_string ("GObject-weak-references");
438 quark_toggle_refs = g_quark_from_static_string ("GObject-toggle-references");
439 quark_notify_queue = g_quark_from_static_string ("GObject-notify-queue");
440 pspec_pool = g_param_spec_pool_new (TRUE);
442 class->constructor = g_object_constructor;
443 class->constructed = g_object_constructed;
444 class->set_property = g_object_do_set_property;
445 class->get_property = g_object_do_get_property;
446 class->dispose = g_object_real_dispose;
447 class->finalize = g_object_finalize;
448 class->dispatch_properties_changed = g_object_dispatch_properties_changed;
449 class->notify = NULL;
453 * @gobject: the object which received the signal.
454 * @pspec: the #GParamSpec of the property which changed.
456 * The notify signal is emitted on an object when one of its
457 * properties has been changed. Note that getting this signal
458 * doesn't guarantee that the value of the property has actually
459 * changed, it may also be emitted when the setter for the property
460 * is called to reinstate the previous value.
462 * This signal is typically used to obtain change notification for a
463 * single property, by specifying the property name as a detail in the
464 * g_signal_connect() call, like this:
466 * g_signal_connect (text_view->buffer, "notify::paste-target-list",
467 * G_CALLBACK (gtk_text_view_target_list_notify),
470 * It is important to note that you must use
471 * <link linkend="canonical-parameter-name">canonical</link> parameter names as
472 * detail strings for the notify signal.
474 gobject_signals[NOTIFY] =
475 g_signal_new (g_intern_static_string ("notify"),
476 G_TYPE_FROM_CLASS (class),
477 G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE | G_SIGNAL_DETAILED | G_SIGNAL_NO_HOOKS | G_SIGNAL_ACTION,
478 G_STRUCT_OFFSET (GObjectClass, notify),
480 g_cclosure_marshal_VOID__PARAM,
484 /* Install a check function that we'll use to verify that classes that
485 * implement an interface implement all properties for that interface
487 g_type_add_interface_check (NULL, object_interface_check_properties);
491 install_property_internal (GType g_type,
495 if (g_param_spec_pool_lookup (pspec_pool, pspec->name, g_type, FALSE))
497 g_warning ("When installing property: type `%s' already has a property named `%s'",
498 g_type_name (g_type),
503 g_param_spec_ref_sink (pspec);
504 PARAM_SPEC_SET_PARAM_ID (pspec, property_id);
505 g_param_spec_pool_insert (pspec_pool, pspec, g_type);
509 * g_object_class_install_property:
510 * @oclass: a #GObjectClass
511 * @property_id: the id for the new property
512 * @pspec: the #GParamSpec for the new property
514 * Installs a new property. This is usually done in the class initializer.
516 * Note that it is possible to redefine a property in a derived class,
517 * by installing a property with the same name. This can be useful at times,
518 * e.g. to change the range of allowed values or the default value.
521 g_object_class_install_property (GObjectClass *class,
525 g_return_if_fail (G_IS_OBJECT_CLASS (class));
526 g_return_if_fail (G_IS_PARAM_SPEC (pspec));
528 if (CLASS_HAS_DERIVED_CLASS (class))
529 g_error ("Attempt to add property %s::%s to class after it was derived",
530 G_OBJECT_CLASS_NAME (class), pspec->name);
532 class->flags |= CLASS_HAS_PROPS_FLAG;
534 if (pspec->flags & G_PARAM_WRITABLE)
535 g_return_if_fail (class->set_property != NULL);
536 if (pspec->flags & G_PARAM_READABLE)
537 g_return_if_fail (class->get_property != NULL);
538 g_return_if_fail (property_id > 0);
539 g_return_if_fail (PARAM_SPEC_PARAM_ID (pspec) == 0); /* paranoid */
540 if (pspec->flags & G_PARAM_CONSTRUCT)
541 g_return_if_fail ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) == 0);
542 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
543 g_return_if_fail (pspec->flags & G_PARAM_WRITABLE);
545 install_property_internal (G_OBJECT_CLASS_TYPE (class), property_id, pspec);
547 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
548 class->construct_properties = g_slist_prepend (class->construct_properties, pspec);
550 /* for property overrides of construct properties, we have to get rid
551 * of the overidden inherited construct property
553 pspec = g_param_spec_pool_lookup (pspec_pool, pspec->name, g_type_parent (G_OBJECT_CLASS_TYPE (class)), TRUE);
554 if (pspec && pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
555 class->construct_properties = g_slist_remove (class->construct_properties, pspec);
559 * g_object_class_install_properties:
560 * @oclass: a #GObjectClass
561 * @n_pspecs: the length of the #GParamSpec<!-- -->s array
562 * @pspecs: (array length=n_pspecs): the #GParamSpec<!-- -->s array
563 * defining the new properties
565 * Installs new properties from an array of #GParamSpec<!-- -->s. This is
566 * usually done in the class initializer.
568 * The property id of each property is the index of each #GParamSpec in
571 * The property id of 0 is treated specially by #GObject and it should not
572 * be used to store a #GParamSpec.
574 * This function should be used if you plan to use a static array of
575 * #GParamSpec<!-- -->s and g_object_notify_by_pspec(). For instance, this
576 * class initialization:
580 * PROP_0, PROP_FOO, PROP_BAR, N_PROPERTIES
583 * static GParamSpec *obj_properties[N_PROPERTIES] = { NULL, };
586 * my_object_class_init (MyObjectClass *klass)
588 * GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
590 * obj_properties[PROP_FOO] =
591 * g_param_spec_int ("foo", "Foo", "Foo",
594 * G_PARAM_READWRITE);
596 * obj_properties[PROP_BAR] =
597 * g_param_spec_string ("bar", "Bar", "Bar",
599 * G_PARAM_READWRITE);
601 * gobject_class->set_property = my_object_set_property;
602 * gobject_class->get_property = my_object_get_property;
603 * g_object_class_install_properties (gobject_class,
609 * allows calling g_object_notify_by_pspec() to notify of property changes:
613 * my_object_set_foo (MyObject *self, gint foo)
615 * if (self->foo != foo)
618 * g_object_notify_by_pspec (G_OBJECT (self), obj_properties[PROP_FOO]);
626 g_object_class_install_properties (GObjectClass *oclass,
630 GType oclass_type, parent_type;
633 g_return_if_fail (G_IS_OBJECT_CLASS (oclass));
634 g_return_if_fail (n_pspecs > 1);
635 g_return_if_fail (pspecs[0] == NULL);
637 if (CLASS_HAS_DERIVED_CLASS (oclass))
638 g_error ("Attempt to add properties to %s after it was derived",
639 G_OBJECT_CLASS_NAME (oclass));
641 oclass_type = G_OBJECT_CLASS_TYPE (oclass);
642 parent_type = g_type_parent (oclass_type);
644 /* we skip the first element of the array as it would have a 0 prop_id */
645 for (i = 1; i < n_pspecs; i++)
647 GParamSpec *pspec = pspecs[i];
649 g_return_if_fail (pspec != NULL);
651 if (pspec->flags & G_PARAM_WRITABLE)
652 g_return_if_fail (oclass->set_property != NULL);
653 if (pspec->flags & G_PARAM_READABLE)
654 g_return_if_fail (oclass->get_property != NULL);
655 g_return_if_fail (PARAM_SPEC_PARAM_ID (pspec) == 0); /* paranoid */
656 if (pspec->flags & G_PARAM_CONSTRUCT)
657 g_return_if_fail ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) == 0);
658 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
659 g_return_if_fail (pspec->flags & G_PARAM_WRITABLE);
661 oclass->flags |= CLASS_HAS_PROPS_FLAG;
662 install_property_internal (oclass_type, i, pspec);
664 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
665 oclass->construct_properties = g_slist_prepend (oclass->construct_properties, pspec);
667 /* for property overrides of construct properties, we have to get rid
668 * of the overidden inherited construct property
670 pspec = g_param_spec_pool_lookup (pspec_pool, pspec->name, parent_type, TRUE);
671 if (pspec && pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
672 oclass->construct_properties = g_slist_remove (oclass->construct_properties, pspec);
677 * g_object_interface_install_property:
678 * @g_iface: any interface vtable for the interface, or the default
679 * vtable for the interface.
680 * @pspec: the #GParamSpec for the new property
682 * Add a property to an interface; this is only useful for interfaces
683 * that are added to GObject-derived types. Adding a property to an
684 * interface forces all objects classes with that interface to have a
685 * compatible property. The compatible property could be a newly
686 * created #GParamSpec, but normally
687 * g_object_class_override_property() will be used so that the object
688 * class only needs to provide an implementation and inherits the
689 * property description, default value, bounds, and so forth from the
690 * interface property.
692 * This function is meant to be called from the interface's default
693 * vtable initialization function (the @class_init member of
694 * #GTypeInfo.) It must not be called after after @class_init has
695 * been called for any object types implementing this interface.
700 g_object_interface_install_property (gpointer g_iface,
703 GTypeInterface *iface_class = g_iface;
705 g_return_if_fail (G_TYPE_IS_INTERFACE (iface_class->g_type));
706 g_return_if_fail (G_IS_PARAM_SPEC (pspec));
707 g_return_if_fail (!G_IS_PARAM_SPEC_OVERRIDE (pspec)); /* paranoid */
708 g_return_if_fail (PARAM_SPEC_PARAM_ID (pspec) == 0); /* paranoid */
710 install_property_internal (iface_class->g_type, 0, pspec);
714 * g_object_class_find_property:
715 * @oclass: a #GObjectClass
716 * @property_name: the name of the property to look up
718 * Looks up the #GParamSpec for a property of a class.
720 * Returns: (transfer none): the #GParamSpec for the property, or
721 * %NULL if the class doesn't have a property of that name
724 g_object_class_find_property (GObjectClass *class,
725 const gchar *property_name)
728 GParamSpec *redirect;
730 g_return_val_if_fail (G_IS_OBJECT_CLASS (class), NULL);
731 g_return_val_if_fail (property_name != NULL, NULL);
733 pspec = g_param_spec_pool_lookup (pspec_pool,
735 G_OBJECT_CLASS_TYPE (class),
739 redirect = g_param_spec_get_redirect_target (pspec);
750 * g_object_interface_find_property:
751 * @g_iface: any interface vtable for the interface, or the default
752 * vtable for the interface
753 * @property_name: name of a property to lookup.
755 * Find the #GParamSpec with the given name for an
756 * interface. Generally, the interface vtable passed in as @g_iface
757 * will be the default vtable from g_type_default_interface_ref(), or,
758 * if you know the interface has already been loaded,
759 * g_type_default_interface_peek().
763 * Returns: (transfer none): the #GParamSpec for the property of the
764 * interface with the name @property_name, or %NULL if no
765 * such property exists.
768 g_object_interface_find_property (gpointer g_iface,
769 const gchar *property_name)
771 GTypeInterface *iface_class = g_iface;
773 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface_class->g_type), NULL);
774 g_return_val_if_fail (property_name != NULL, NULL);
776 return g_param_spec_pool_lookup (pspec_pool,
783 * g_object_class_override_property:
784 * @oclass: a #GObjectClass
785 * @property_id: the new property ID
786 * @name: the name of a property registered in a parent class or
787 * in an interface of this class.
789 * Registers @property_id as referring to a property with the
790 * name @name in a parent class or in an interface implemented
791 * by @oclass. This allows this class to <firstterm>override</firstterm>
792 * a property implementation in a parent class or to provide
793 * the implementation of a property from an interface.
796 * Internally, overriding is implemented by creating a property of type
797 * #GParamSpecOverride; generally operations that query the properties of
798 * the object class, such as g_object_class_find_property() or
799 * g_object_class_list_properties() will return the overridden
800 * property. However, in one case, the @construct_properties argument of
801 * the @constructor virtual function, the #GParamSpecOverride is passed
802 * instead, so that the @param_id field of the #GParamSpec will be
803 * correct. For virtually all uses, this makes no difference. If you
804 * need to get the overridden property, you can call
805 * g_param_spec_get_redirect_target().
811 g_object_class_override_property (GObjectClass *oclass,
815 GParamSpec *overridden = NULL;
819 g_return_if_fail (G_IS_OBJECT_CLASS (oclass));
820 g_return_if_fail (property_id > 0);
821 g_return_if_fail (name != NULL);
823 /* Find the overridden property; first check parent types
825 parent_type = g_type_parent (G_OBJECT_CLASS_TYPE (oclass));
826 if (parent_type != G_TYPE_NONE)
827 overridden = g_param_spec_pool_lookup (pspec_pool,
836 /* Now check interfaces
838 ifaces = g_type_interfaces (G_OBJECT_CLASS_TYPE (oclass), &n_ifaces);
839 while (n_ifaces-- && !overridden)
841 overridden = g_param_spec_pool_lookup (pspec_pool,
852 g_warning ("%s: Can't find property to override for '%s::%s'",
853 G_STRFUNC, G_OBJECT_CLASS_NAME (oclass), name);
857 new = g_param_spec_override (name, overridden);
858 g_object_class_install_property (oclass, property_id, new);
862 * g_object_class_list_properties:
863 * @oclass: a #GObjectClass
864 * @n_properties: (out): return location for the length of the returned array
866 * Get an array of #GParamSpec* for all properties of a class.
868 * Returns: (array length=n_properties) (transfer container): an array of
869 * #GParamSpec* which should be freed after use
871 GParamSpec** /* free result */
872 g_object_class_list_properties (GObjectClass *class,
873 guint *n_properties_p)
878 g_return_val_if_fail (G_IS_OBJECT_CLASS (class), NULL);
880 pspecs = g_param_spec_pool_list (pspec_pool,
881 G_OBJECT_CLASS_TYPE (class),
890 * g_object_interface_list_properties:
891 * @g_iface: any interface vtable for the interface, or the default
892 * vtable for the interface
893 * @n_properties_p: (out): location to store number of properties returned.
895 * Lists the properties of an interface.Generally, the interface
896 * vtable passed in as @g_iface will be the default vtable from
897 * g_type_default_interface_ref(), or, if you know the interface has
898 * already been loaded, g_type_default_interface_peek().
902 * Returns: (array length=n_properties_p) (transfer container): a
903 * pointer to an array of pointers to #GParamSpec
904 * structures. The paramspecs are owned by GLib, but the
905 * array should be freed with g_free() when you are done with
909 g_object_interface_list_properties (gpointer g_iface,
910 guint *n_properties_p)
912 GTypeInterface *iface_class = g_iface;
916 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface_class->g_type), NULL);
918 pspecs = g_param_spec_pool_list (pspec_pool,
928 g_object_init (GObject *object,
931 object->ref_count = 1;
932 object->qdata = NULL;
934 if (CLASS_HAS_PROPS (class))
936 /* freeze object's notification queue, g_object_newv() preserves pairedness */
937 g_object_notify_queue_freeze (object, FALSE);
940 if (CLASS_HAS_CUSTOM_CONSTRUCTOR (class))
942 /* enter construction list for notify_queue_thaw() and to allow construct-only properties */
943 G_LOCK (construction_mutex);
944 construction_objects = g_slist_prepend (construction_objects, object);
945 G_UNLOCK (construction_mutex);
948 #ifdef G_ENABLE_DEBUG
951 G_LOCK (debug_objects);
952 debug_objects_count++;
953 g_hash_table_insert (debug_objects_ht, object, object);
954 G_UNLOCK (debug_objects);
956 #endif /* G_ENABLE_DEBUG */
960 g_object_do_set_property (GObject *object,
968 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
974 g_object_do_get_property (GObject *object,
982 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
988 g_object_real_dispose (GObject *object)
990 g_signal_handlers_destroy (object);
991 g_datalist_id_set_data (&object->qdata, quark_closure_array, NULL);
992 g_datalist_id_set_data (&object->qdata, quark_weak_refs, NULL);
996 g_object_finalize (GObject *object)
998 g_datalist_clear (&object->qdata);
1000 #ifdef G_ENABLE_DEBUG
1003 G_LOCK (debug_objects);
1004 g_assert (g_hash_table_lookup (debug_objects_ht, object) == object);
1005 g_hash_table_remove (debug_objects_ht, object);
1006 debug_objects_count--;
1007 G_UNLOCK (debug_objects);
1009 #endif /* G_ENABLE_DEBUG */
1014 g_object_dispatch_properties_changed (GObject *object,
1016 GParamSpec **pspecs)
1020 for (i = 0; i < n_pspecs; i++)
1021 g_signal_emit (object, gobject_signals[NOTIFY], g_quark_from_string (pspecs[i]->name), pspecs[i]);
1025 * g_object_run_dispose:
1026 * @object: a #GObject
1028 * Releases all references to other objects. This can be used to break
1031 * This functions should only be called from object system implementations.
1034 g_object_run_dispose (GObject *object)
1036 g_return_if_fail (G_IS_OBJECT (object));
1037 g_return_if_fail (object->ref_count > 0);
1039 g_object_ref (object);
1040 TRACE (GOBJECT_OBJECT_DISPOSE(object,G_TYPE_FROM_INSTANCE(object), 0));
1041 G_OBJECT_GET_CLASS (object)->dispose (object);
1042 TRACE (GOBJECT_OBJECT_DISPOSE_END(object,G_TYPE_FROM_INSTANCE(object), 0));
1043 g_object_unref (object);
1047 * g_object_freeze_notify:
1048 * @object: a #GObject
1050 * Increases the freeze count on @object. If the freeze count is
1051 * non-zero, the emission of "notify" signals on @object is
1052 * stopped. The signals are queued until the freeze count is decreased
1055 * This is necessary for accessors that modify multiple properties to prevent
1056 * premature notification while the object is still being modified.
1059 g_object_freeze_notify (GObject *object)
1061 g_return_if_fail (G_IS_OBJECT (object));
1063 if (g_atomic_int_get (&object->ref_count) == 0)
1066 g_object_ref (object);
1067 g_object_notify_queue_freeze (object, FALSE);
1068 g_object_unref (object);
1072 get_notify_pspec (GParamSpec *pspec)
1074 GParamSpec *redirected;
1076 /* we don't notify on non-READABLE parameters */
1077 if (~pspec->flags & G_PARAM_READABLE)
1080 /* if the paramspec is redirected, notify on the target */
1081 redirected = g_param_spec_get_redirect_target (pspec);
1082 if (redirected != NULL)
1085 /* else, notify normally */
1090 g_object_notify_by_spec_internal (GObject *object,
1093 GParamSpec *notify_pspec;
1095 notify_pspec = get_notify_pspec (pspec);
1097 if (notify_pspec != NULL)
1099 GObjectNotifyQueue *nqueue;
1101 /* conditional freeze: only increase freeze count if already frozen */
1102 nqueue = g_object_notify_queue_freeze (object, TRUE);
1106 /* we're frozen, so add to the queue and release our freeze */
1107 g_object_notify_queue_add (object, nqueue, notify_pspec);
1108 g_object_notify_queue_thaw (object, nqueue);
1111 /* not frozen, so just dispatch the notification directly */
1112 G_OBJECT_GET_CLASS (object)
1113 ->dispatch_properties_changed (object, 1, ¬ify_pspec);
1119 * @object: a #GObject
1120 * @property_name: the name of a property installed on the class of @object.
1122 * Emits a "notify" signal for the property @property_name on @object.
1124 * When possible, eg. when signaling a property change from within the class
1125 * that registered the property, you should use g_object_notify_by_pspec()
1129 g_object_notify (GObject *object,
1130 const gchar *property_name)
1134 g_return_if_fail (G_IS_OBJECT (object));
1135 g_return_if_fail (property_name != NULL);
1136 if (g_atomic_int_get (&object->ref_count) == 0)
1139 g_object_ref (object);
1140 /* We don't need to get the redirect target
1141 * (by, e.g. calling g_object_class_find_property())
1142 * because g_object_notify_queue_add() does that
1144 pspec = g_param_spec_pool_lookup (pspec_pool,
1146 G_OBJECT_TYPE (object),
1150 g_warning ("%s: object class `%s' has no property named `%s'",
1152 G_OBJECT_TYPE_NAME (object),
1155 g_object_notify_by_spec_internal (object, pspec);
1156 g_object_unref (object);
1160 * g_object_notify_by_pspec:
1161 * @object: a #GObject
1162 * @pspec: the #GParamSpec of a property installed on the class of @object.
1164 * Emits a "notify" signal for the property specified by @pspec on @object.
1166 * This function omits the property name lookup, hence it is faster than
1167 * g_object_notify().
1169 * One way to avoid using g_object_notify() from within the
1170 * class that registered the properties, and using g_object_notify_by_pspec()
1171 * instead, is to store the GParamSpec used with
1172 * g_object_class_install_property() inside a static array, e.g.:
1182 * static GParamSpec *properties[PROP_LAST];
1185 * my_object_class_init (MyObjectClass *klass)
1187 * properties[PROP_FOO] = g_param_spec_int ("foo", "Foo", "The foo",
1190 * G_PARAM_READWRITE);
1191 * g_object_class_install_property (gobject_class,
1193 * properties[PROP_FOO]);
1197 * and then notify a change on the "foo" property with:
1200 * g_object_notify_by_pspec (self, properties[PROP_FOO]);
1206 g_object_notify_by_pspec (GObject *object,
1210 g_return_if_fail (G_IS_OBJECT (object));
1211 g_return_if_fail (G_IS_PARAM_SPEC (pspec));
1213 g_object_ref (object);
1214 g_object_notify_by_spec_internal (object, pspec);
1215 g_object_unref (object);
1219 * g_object_thaw_notify:
1220 * @object: a #GObject
1222 * Reverts the effect of a previous call to
1223 * g_object_freeze_notify(). The freeze count is decreased on @object
1224 * and when it reaches zero, all queued "notify" signals are emitted.
1226 * It is an error to call this function when the freeze count is zero.
1229 g_object_thaw_notify (GObject *object)
1231 GObjectNotifyQueue *nqueue;
1233 g_return_if_fail (G_IS_OBJECT (object));
1234 if (g_atomic_int_get (&object->ref_count) == 0)
1237 g_object_ref (object);
1239 /* FIXME: Freezing is the only way to get at the notify queue.
1240 * So we freeze once and then thaw twice.
1242 nqueue = g_object_notify_queue_freeze (object, FALSE);
1243 g_object_notify_queue_thaw (object, nqueue);
1244 g_object_notify_queue_thaw (object, nqueue);
1246 g_object_unref (object);
1250 object_get_property (GObject *object,
1254 GObjectClass *class = g_type_class_peek (pspec->owner_type);
1255 guint param_id = PARAM_SPEC_PARAM_ID (pspec);
1256 GParamSpec *redirect;
1260 g_warning ("'%s::%s' is not a valid property name; '%s' is not a GObject subtype",
1261 g_type_name (pspec->owner_type), pspec->name, g_type_name (pspec->owner_type));
1265 redirect = g_param_spec_get_redirect_target (pspec);
1269 class->get_property (object, param_id, value, pspec);
1273 object_set_property (GObject *object,
1275 const GValue *value,
1276 GObjectNotifyQueue *nqueue)
1278 GValue tmp_value = G_VALUE_INIT;
1279 GObjectClass *class = g_type_class_peek (pspec->owner_type);
1280 guint param_id = PARAM_SPEC_PARAM_ID (pspec);
1281 GParamSpec *redirect;
1282 static const gchar * enable_diagnostic = NULL;
1286 g_warning ("'%s::%s' is not a valid property name; '%s' is not a GObject subtype",
1287 g_type_name (pspec->owner_type), pspec->name, g_type_name (pspec->owner_type));
1291 redirect = g_param_spec_get_redirect_target (pspec);
1295 if (G_UNLIKELY (!enable_diagnostic))
1297 enable_diagnostic = g_getenv ("G_ENABLE_DIAGNOSTIC");
1298 if (!enable_diagnostic)
1299 enable_diagnostic = "0";
1302 if (enable_diagnostic[0] == '1')
1304 if (pspec->flags & G_PARAM_DEPRECATED)
1305 g_warning ("The property %s:%s is deprecated and shouldn't be used "
1306 "anymore. It will be removed in a future version.",
1307 G_OBJECT_TYPE_NAME (object), pspec->name);
1310 /* provide a copy to work from, convert (if necessary) and validate */
1311 g_value_init (&tmp_value, pspec->value_type);
1312 if (!g_value_transform (value, &tmp_value))
1313 g_warning ("unable to set property `%s' of type `%s' from value of type `%s'",
1315 g_type_name (pspec->value_type),
1316 G_VALUE_TYPE_NAME (value));
1317 else if (g_param_value_validate (pspec, &tmp_value) && !(pspec->flags & G_PARAM_LAX_VALIDATION))
1319 gchar *contents = g_strdup_value_contents (value);
1321 g_warning ("value \"%s\" of type `%s' is invalid or out of range for property `%s' of type `%s'",
1323 G_VALUE_TYPE_NAME (value),
1325 g_type_name (pspec->value_type));
1330 GParamSpec *notify_pspec;
1332 class->set_property (object, param_id, &tmp_value, pspec);
1334 notify_pspec = get_notify_pspec (pspec);
1336 if (notify_pspec != NULL)
1337 g_object_notify_queue_add (object, nqueue, notify_pspec);
1339 g_value_unset (&tmp_value);
1343 object_interface_check_properties (gpointer func_data,
1346 GTypeInterface *iface_class = g_iface;
1347 GObjectClass *class;
1348 GType iface_type = iface_class->g_type;
1349 GParamSpec **pspecs;
1352 class = g_type_class_ref (iface_class->g_instance_type);
1354 if (!G_IS_OBJECT_CLASS (class))
1357 pspecs = g_param_spec_pool_list (pspec_pool, iface_type, &n);
1361 GParamSpec *class_pspec = g_param_spec_pool_lookup (pspec_pool,
1363 G_OBJECT_CLASS_TYPE (class),
1368 g_critical ("Object class %s doesn't implement property "
1369 "'%s' from interface '%s'",
1370 g_type_name (G_OBJECT_CLASS_TYPE (class)),
1372 g_type_name (iface_type));
1377 /* The implementation paramspec must have a less restrictive
1378 * type than the interface parameter spec for set() and a
1379 * more restrictive type for get(). We just require equality,
1380 * rather than doing something more complicated checking
1381 * the READABLE and WRITABLE flags. We also simplify here
1382 * by only checking the value type, not the G_PARAM_SPEC_TYPE.
1385 !g_type_is_a (pspecs[n]->value_type,
1386 class_pspec->value_type))
1388 g_critical ("Property '%s' on class '%s' has type '%s' "
1389 "which is different from the type '%s', "
1390 "of the property on interface '%s'\n",
1392 g_type_name (G_OBJECT_CLASS_TYPE (class)),
1393 g_type_name (G_PARAM_SPEC_VALUE_TYPE (class_pspec)),
1394 g_type_name (G_PARAM_SPEC_VALUE_TYPE (pspecs[n])),
1395 g_type_name (iface_type));
1398 #define SUBSET(a,b,mask) (((a) & ~(b) & (mask)) == 0)
1400 /* CONSTRUCT and CONSTRUCT_ONLY add restrictions.
1401 * READABLE and WRITABLE remove restrictions. The implementation
1402 * paramspec must have less restrictive flags.
1405 (!SUBSET (class_pspec->flags,
1407 G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY) ||
1408 !SUBSET (pspecs[n]->flags,
1410 G_PARAM_READABLE | G_PARAM_WRITABLE)))
1412 g_critical ("Flags for property '%s' on class '%s' "
1413 "are not compatible with the property on"
1416 g_type_name (G_OBJECT_CLASS_TYPE (class)),
1417 g_type_name (iface_type));
1424 g_type_class_unref (class);
1428 g_object_get_type (void)
1430 return G_TYPE_OBJECT;
1434 * g_object_new: (skip)
1435 * @object_type: the type id of the #GObject subtype to instantiate
1436 * @first_property_name: the name of the first property
1437 * @...: the value of the first property, followed optionally by more
1438 * name/value pairs, followed by %NULL
1440 * Creates a new instance of a #GObject subtype and sets its properties.
1442 * Construction parameters (see #G_PARAM_CONSTRUCT, #G_PARAM_CONSTRUCT_ONLY)
1443 * which are not explicitly specified are set to their default values.
1445 * Returns: (transfer full): a new instance of @object_type
1448 g_object_new (GType object_type,
1449 const gchar *first_property_name,
1455 g_return_val_if_fail (G_TYPE_IS_OBJECT (object_type), NULL);
1457 /* short circuit for calls supplying no properties */
1458 if (!first_property_name)
1459 return g_object_newv (object_type, 0, NULL);
1461 va_start (var_args, first_property_name);
1462 object = g_object_new_valist (object_type, first_property_name, var_args);
1469 slist_maybe_remove (GSList **slist,
1472 GSList *last = NULL, *node = *slist;
1475 if (node->data == data)
1478 last->next = node->next;
1480 *slist = node->next;
1481 g_slist_free_1 (node);
1490 static inline gboolean
1491 object_in_construction_list (GObject *object)
1493 gboolean in_construction;
1494 G_LOCK (construction_mutex);
1495 in_construction = g_slist_find (construction_objects, object) != NULL;
1496 G_UNLOCK (construction_mutex);
1497 return in_construction;
1502 * @object_type: the type id of the #GObject subtype to instantiate
1503 * @n_parameters: the length of the @parameters array
1504 * @parameters: (array length=n_parameters): an array of #GParameter
1506 * Creates a new instance of a #GObject subtype and sets its properties.
1508 * Construction parameters (see #G_PARAM_CONSTRUCT, #G_PARAM_CONSTRUCT_ONLY)
1509 * which are not explicitly specified are set to their default values.
1511 * Rename to: g_object_new
1512 * Returns: (type GObject.Object) (transfer full): a new instance of
1516 g_object_newv (GType object_type,
1518 GParameter *parameters)
1520 GObjectConstructParam *cparams = NULL, *oparams;
1521 GObjectNotifyQueue *nqueue = NULL; /* shouldn't be initialized, just to silence compiler */
1523 GObjectClass *class, *unref_class = NULL;
1525 guint n_total_cparams = 0, n_cparams = 0, n_oparams = 0, n_cvalues;
1527 GList *clist = NULL;
1528 gboolean newly_constructed;
1531 g_return_val_if_fail (G_TYPE_IS_OBJECT (object_type), NULL);
1533 class = g_type_class_peek_static (object_type);
1535 class = unref_class = g_type_class_ref (object_type);
1536 for (slist = class->construct_properties; slist; slist = slist->next)
1538 clist = g_list_prepend (clist, slist->data);
1539 n_total_cparams += 1;
1542 if (n_parameters == 0 && n_total_cparams == 0)
1544 /* This is a simple object with no construct properties, and
1545 * no properties are being set, so short circuit the parameter
1546 * handling. This speeds up simple object construction.
1549 object = class->constructor (object_type, 0, NULL);
1550 goto did_construction;
1553 /* collect parameters, sort into construction and normal ones */
1554 oparams = g_new (GObjectConstructParam, n_parameters);
1555 cparams = g_new (GObjectConstructParam, n_total_cparams);
1556 for (i = 0; i < n_parameters; i++)
1558 GValue *value = ¶meters[i].value;
1559 GParamSpec *pspec = g_param_spec_pool_lookup (pspec_pool,
1565 g_warning ("%s: object class `%s' has no property named `%s'",
1567 g_type_name (object_type),
1568 parameters[i].name);
1571 if (!(pspec->flags & G_PARAM_WRITABLE))
1573 g_warning ("%s: property `%s' of object class `%s' is not writable",
1576 g_type_name (object_type));
1579 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
1581 GList *list = g_list_find (clist, pspec);
1585 g_warning ("%s: construct property \"%s\" for object `%s' can't be set twice",
1586 G_STRFUNC, pspec->name, g_type_name (object_type));
1589 cparams[n_cparams].pspec = pspec;
1590 cparams[n_cparams].value = value;
1595 list->prev->next = list->next;
1597 list->next->prev = list->prev;
1598 g_list_free_1 (list);
1602 oparams[n_oparams].pspec = pspec;
1603 oparams[n_oparams].value = value;
1608 /* set remaining construction properties to default values */
1609 n_cvalues = n_total_cparams - n_cparams;
1610 cvalues = g_new (GValue, n_cvalues);
1613 GList *tmp = clist->next;
1614 GParamSpec *pspec = clist->data;
1615 GValue *value = cvalues + n_total_cparams - n_cparams - 1;
1618 g_value_init (value, pspec->value_type);
1619 g_param_value_set_default (pspec, value);
1621 cparams[n_cparams].pspec = pspec;
1622 cparams[n_cparams].value = value;
1625 g_list_free_1 (clist);
1629 /* construct object from construction parameters */
1630 object = class->constructor (object_type, n_total_cparams, cparams);
1631 /* free construction values */
1634 g_value_unset (cvalues + n_cvalues);
1638 if (CLASS_HAS_CUSTOM_CONSTRUCTOR (class))
1640 /* adjust freeze_count according to g_object_init() and remaining properties */
1641 G_LOCK (construction_mutex);
1642 newly_constructed = slist_maybe_remove (&construction_objects, object);
1643 G_UNLOCK (construction_mutex);
1646 newly_constructed = TRUE;
1648 if (CLASS_HAS_PROPS (class))
1650 if (newly_constructed || n_oparams)
1651 nqueue = g_object_notify_queue_freeze (object, FALSE);
1652 if (newly_constructed)
1653 g_object_notify_queue_thaw (object, nqueue);
1656 /* run 'constructed' handler if there is a custom one */
1657 if (newly_constructed && CLASS_HAS_CUSTOM_CONSTRUCTED (class))
1658 class->constructed (object);
1660 /* set remaining properties */
1661 for (i = 0; i < n_oparams; i++)
1662 object_set_property (object, oparams[i].pspec, oparams[i].value, nqueue);
1665 if (CLASS_HAS_PROPS (class))
1667 /* release our own freeze count and handle notifications */
1668 if (newly_constructed || n_oparams)
1669 g_object_notify_queue_thaw (object, nqueue);
1673 g_type_class_unref (unref_class);
1679 * g_object_new_valist: (skip)
1680 * @object_type: the type id of the #GObject subtype to instantiate
1681 * @first_property_name: the name of the first property
1682 * @var_args: the value of the first property, followed optionally by more
1683 * name/value pairs, followed by %NULL
1685 * Creates a new instance of a #GObject subtype and sets its properties.
1687 * Construction parameters (see #G_PARAM_CONSTRUCT, #G_PARAM_CONSTRUCT_ONLY)
1688 * which are not explicitly specified are set to their default values.
1690 * Returns: a new instance of @object_type
1693 g_object_new_valist (GType object_type,
1694 const gchar *first_property_name,
1697 GObjectClass *class;
1701 guint n_params = 0, n_alloced_params = 16;
1703 g_return_val_if_fail (G_TYPE_IS_OBJECT (object_type), NULL);
1705 if (!first_property_name)
1706 return g_object_newv (object_type, 0, NULL);
1708 class = g_type_class_ref (object_type);
1710 params = g_new0 (GParameter, n_alloced_params);
1711 name = first_property_name;
1714 gchar *error = NULL;
1715 GParamSpec *pspec = g_param_spec_pool_lookup (pspec_pool,
1721 g_warning ("%s: object class `%s' has no property named `%s'",
1723 g_type_name (object_type),
1727 if (n_params >= n_alloced_params)
1729 n_alloced_params += 16;
1730 params = g_renew (GParameter, params, n_alloced_params);
1731 memset (params + n_params, 0, 16 * (sizeof *params));
1733 params[n_params].name = name;
1734 G_VALUE_COLLECT_INIT (¶ms[n_params].value, pspec->value_type,
1735 var_args, 0, &error);
1738 g_warning ("%s: %s", G_STRFUNC, error);
1740 g_value_unset (¶ms[n_params].value);
1744 name = va_arg (var_args, gchar*);
1747 object = g_object_newv (object_type, n_params, params);
1750 g_value_unset (¶ms[n_params].value);
1753 g_type_class_unref (class);
1759 g_object_constructor (GType type,
1760 guint n_construct_properties,
1761 GObjectConstructParam *construct_params)
1766 object = (GObject*) g_type_create_instance (type);
1768 /* set construction parameters */
1769 if (n_construct_properties)
1771 GObjectNotifyQueue *nqueue = g_object_notify_queue_freeze (object, FALSE);
1773 /* set construct properties */
1774 while (n_construct_properties--)
1776 GValue *value = construct_params->value;
1777 GParamSpec *pspec = construct_params->pspec;
1780 object_set_property (object, pspec, value, nqueue);
1782 g_object_notify_queue_thaw (object, nqueue);
1783 /* the notification queue is still frozen from g_object_init(), so
1784 * we don't need to handle it here, g_object_newv() takes
1793 g_object_constructed (GObject *object)
1795 /* empty default impl to allow unconditional upchaining */
1799 * g_object_set_valist: (skip)
1800 * @object: a #GObject
1801 * @first_property_name: name of the first property to set
1802 * @var_args: value for the first property, followed optionally by more
1803 * name/value pairs, followed by %NULL
1805 * Sets properties on an object.
1808 g_object_set_valist (GObject *object,
1809 const gchar *first_property_name,
1812 GObjectNotifyQueue *nqueue;
1815 g_return_if_fail (G_IS_OBJECT (object));
1817 g_object_ref (object);
1818 nqueue = g_object_notify_queue_freeze (object, FALSE);
1820 name = first_property_name;
1823 GValue value = G_VALUE_INIT;
1825 gchar *error = NULL;
1827 pspec = g_param_spec_pool_lookup (pspec_pool,
1829 G_OBJECT_TYPE (object),
1833 g_warning ("%s: object class `%s' has no property named `%s'",
1835 G_OBJECT_TYPE_NAME (object),
1839 if (!(pspec->flags & G_PARAM_WRITABLE))
1841 g_warning ("%s: property `%s' of object class `%s' is not writable",
1844 G_OBJECT_TYPE_NAME (object));
1847 if ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) && !object_in_construction_list (object))
1849 g_warning ("%s: construct property \"%s\" for object `%s' can't be set after construction",
1850 G_STRFUNC, pspec->name, G_OBJECT_TYPE_NAME (object));
1854 G_VALUE_COLLECT_INIT (&value, pspec->value_type, var_args,
1858 g_warning ("%s: %s", G_STRFUNC, error);
1860 g_value_unset (&value);
1864 object_set_property (object, pspec, &value, nqueue);
1865 g_value_unset (&value);
1867 name = va_arg (var_args, gchar*);
1870 g_object_notify_queue_thaw (object, nqueue);
1871 g_object_unref (object);
1875 * g_object_get_valist: (skip)
1876 * @object: a #GObject
1877 * @first_property_name: name of the first property to get
1878 * @var_args: return location for the first property, followed optionally by more
1879 * name/return location pairs, followed by %NULL
1881 * Gets properties of an object.
1883 * In general, a copy is made of the property contents and the caller
1884 * is responsible for freeing the memory in the appropriate manner for
1885 * the type, for instance by calling g_free() or g_object_unref().
1887 * See g_object_get().
1890 g_object_get_valist (GObject *object,
1891 const gchar *first_property_name,
1896 g_return_if_fail (G_IS_OBJECT (object));
1898 g_object_ref (object);
1900 name = first_property_name;
1904 GValue value = G_VALUE_INIT;
1908 pspec = g_param_spec_pool_lookup (pspec_pool,
1910 G_OBJECT_TYPE (object),
1914 g_warning ("%s: object class `%s' has no property named `%s'",
1916 G_OBJECT_TYPE_NAME (object),
1920 if (!(pspec->flags & G_PARAM_READABLE))
1922 g_warning ("%s: property `%s' of object class `%s' is not readable",
1925 G_OBJECT_TYPE_NAME (object));
1929 g_value_init (&value, pspec->value_type);
1931 object_get_property (object, pspec, &value);
1933 G_VALUE_LCOPY (&value, var_args, 0, &error);
1936 g_warning ("%s: %s", G_STRFUNC, error);
1938 g_value_unset (&value);
1942 g_value_unset (&value);
1944 name = va_arg (var_args, gchar*);
1947 g_object_unref (object);
1951 * g_object_set: (skip)
1952 * @object: a #GObject
1953 * @first_property_name: name of the first property to set
1954 * @...: value for the first property, followed optionally by more
1955 * name/value pairs, followed by %NULL
1957 * Sets properties on an object.
1960 g_object_set (gpointer _object,
1961 const gchar *first_property_name,
1964 GObject *object = _object;
1967 g_return_if_fail (G_IS_OBJECT (object));
1969 va_start (var_args, first_property_name);
1970 g_object_set_valist (object, first_property_name, var_args);
1975 * g_object_get: (skip)
1976 * @object: a #GObject
1977 * @first_property_name: name of the first property to get
1978 * @...: return location for the first property, followed optionally by more
1979 * name/return location pairs, followed by %NULL
1981 * Gets properties of an object.
1983 * In general, a copy is made of the property contents and the caller
1984 * is responsible for freeing the memory in the appropriate manner for
1985 * the type, for instance by calling g_free() or g_object_unref().
1988 * <title>Using g_object_get(<!-- -->)</title>
1989 * An example of using g_object_get() to get the contents
1990 * of three properties - one of type #G_TYPE_INT,
1991 * one of type #G_TYPE_STRING, and one of type #G_TYPE_OBJECT:
1997 * g_object_get (my_object,
1998 * "int-property", &intval,
1999 * "str-property", &strval,
2000 * "obj-property", &objval,
2003 * // Do something with intval, strval, objval
2006 * g_object_unref (objval);
2011 g_object_get (gpointer _object,
2012 const gchar *first_property_name,
2015 GObject *object = _object;
2018 g_return_if_fail (G_IS_OBJECT (object));
2020 va_start (var_args, first_property_name);
2021 g_object_get_valist (object, first_property_name, var_args);
2026 * g_object_set_property:
2027 * @object: a #GObject
2028 * @property_name: the name of the property to set
2031 * Sets a property on an object.
2034 g_object_set_property (GObject *object,
2035 const gchar *property_name,
2036 const GValue *value)
2038 GObjectNotifyQueue *nqueue;
2041 g_return_if_fail (G_IS_OBJECT (object));
2042 g_return_if_fail (property_name != NULL);
2043 g_return_if_fail (G_IS_VALUE (value));
2045 g_object_ref (object);
2046 nqueue = g_object_notify_queue_freeze (object, FALSE);
2048 pspec = g_param_spec_pool_lookup (pspec_pool,
2050 G_OBJECT_TYPE (object),
2053 g_warning ("%s: object class `%s' has no property named `%s'",
2055 G_OBJECT_TYPE_NAME (object),
2057 else if (!(pspec->flags & G_PARAM_WRITABLE))
2058 g_warning ("%s: property `%s' of object class `%s' is not writable",
2061 G_OBJECT_TYPE_NAME (object));
2062 else if ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) && !object_in_construction_list (object))
2063 g_warning ("%s: construct property \"%s\" for object `%s' can't be set after construction",
2064 G_STRFUNC, pspec->name, G_OBJECT_TYPE_NAME (object));
2066 object_set_property (object, pspec, value, nqueue);
2068 g_object_notify_queue_thaw (object, nqueue);
2069 g_object_unref (object);
2073 * g_object_get_property:
2074 * @object: a #GObject
2075 * @property_name: the name of the property to get
2076 * @value: return location for the property value
2078 * Gets a property of an object. @value must have been initialized to the
2079 * expected type of the property (or a type to which the expected type can be
2080 * transformed) using g_value_init().
2082 * In general, a copy is made of the property contents and the caller is
2083 * responsible for freeing the memory by calling g_value_unset().
2085 * Note that g_object_get_property() is really intended for language
2086 * bindings, g_object_get() is much more convenient for C programming.
2089 g_object_get_property (GObject *object,
2090 const gchar *property_name,
2095 g_return_if_fail (G_IS_OBJECT (object));
2096 g_return_if_fail (property_name != NULL);
2097 g_return_if_fail (G_IS_VALUE (value));
2099 g_object_ref (object);
2101 pspec = g_param_spec_pool_lookup (pspec_pool,
2103 G_OBJECT_TYPE (object),
2106 g_warning ("%s: object class `%s' has no property named `%s'",
2108 G_OBJECT_TYPE_NAME (object),
2110 else if (!(pspec->flags & G_PARAM_READABLE))
2111 g_warning ("%s: property `%s' of object class `%s' is not readable",
2114 G_OBJECT_TYPE_NAME (object));
2117 GValue *prop_value, tmp_value = G_VALUE_INIT;
2119 /* auto-conversion of the callers value type
2121 if (G_VALUE_TYPE (value) == pspec->value_type)
2123 g_value_reset (value);
2126 else if (!g_value_type_transformable (pspec->value_type, G_VALUE_TYPE (value)))
2128 g_warning ("%s: can't retrieve property `%s' of type `%s' as value of type `%s'",
2129 G_STRFUNC, pspec->name,
2130 g_type_name (pspec->value_type),
2131 G_VALUE_TYPE_NAME (value));
2132 g_object_unref (object);
2137 g_value_init (&tmp_value, pspec->value_type);
2138 prop_value = &tmp_value;
2140 object_get_property (object, pspec, prop_value);
2141 if (prop_value != value)
2143 g_value_transform (prop_value, value);
2144 g_value_unset (&tmp_value);
2148 g_object_unref (object);
2152 * g_object_connect: (skip)
2153 * @object: a #GObject
2154 * @signal_spec: the spec for the first signal
2155 * @...: #GCallback for the first signal, followed by data for the
2156 * first signal, followed optionally by more signal
2157 * spec/callback/data triples, followed by %NULL
2159 * A convenience function to connect multiple signals at once.
2161 * The signal specs expected by this function have the form
2162 * "modifier::signal_name", where modifier can be one of the following:
2165 * <term>signal</term>
2167 * equivalent to <literal>g_signal_connect_data (..., NULL, 0)</literal>
2168 * </para></listitem>
2171 * <term>object_signal</term>
2172 * <term>object-signal</term>
2174 * equivalent to <literal>g_signal_connect_object (..., 0)</literal>
2175 * </para></listitem>
2178 * <term>swapped_signal</term>
2179 * <term>swapped-signal</term>
2181 * equivalent to <literal>g_signal_connect_data (..., NULL, G_CONNECT_SWAPPED)</literal>
2182 * </para></listitem>
2185 * <term>swapped_object_signal</term>
2186 * <term>swapped-object-signal</term>
2188 * equivalent to <literal>g_signal_connect_object (..., G_CONNECT_SWAPPED)</literal>
2189 * </para></listitem>
2192 * <term>signal_after</term>
2193 * <term>signal-after</term>
2195 * equivalent to <literal>g_signal_connect_data (..., NULL, G_CONNECT_AFTER)</literal>
2196 * </para></listitem>
2199 * <term>object_signal_after</term>
2200 * <term>object-signal-after</term>
2202 * equivalent to <literal>g_signal_connect_object (..., G_CONNECT_AFTER)</literal>
2203 * </para></listitem>
2206 * <term>swapped_signal_after</term>
2207 * <term>swapped-signal-after</term>
2209 * equivalent to <literal>g_signal_connect_data (..., NULL, G_CONNECT_SWAPPED | G_CONNECT_AFTER)</literal>
2210 * </para></listitem>
2213 * <term>swapped_object_signal_after</term>
2214 * <term>swapped-object-signal-after</term>
2216 * equivalent to <literal>g_signal_connect_object (..., G_CONNECT_SWAPPED | G_CONNECT_AFTER)</literal>
2217 * </para></listitem>
2222 * menu->toplevel = g_object_connect (g_object_new (GTK_TYPE_WINDOW,
2223 * "type", GTK_WINDOW_POPUP,
2226 * "signal::event", gtk_menu_window_event, menu,
2227 * "signal::size_request", gtk_menu_window_size_request, menu,
2228 * "signal::destroy", gtk_widget_destroyed, &menu->toplevel,
2232 * Returns: (transfer none): @object
2235 g_object_connect (gpointer _object,
2236 const gchar *signal_spec,
2239 GObject *object = _object;
2242 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
2243 g_return_val_if_fail (object->ref_count > 0, object);
2245 va_start (var_args, signal_spec);
2248 GCallback callback = va_arg (var_args, GCallback);
2249 gpointer data = va_arg (var_args, gpointer);
2251 if (strncmp (signal_spec, "signal::", 8) == 0)
2252 g_signal_connect_data (object, signal_spec + 8,
2253 callback, data, NULL,
2255 else if (strncmp (signal_spec, "object_signal::", 15) == 0 ||
2256 strncmp (signal_spec, "object-signal::", 15) == 0)
2257 g_signal_connect_object (object, signal_spec + 15,
2260 else if (strncmp (signal_spec, "swapped_signal::", 16) == 0 ||
2261 strncmp (signal_spec, "swapped-signal::", 16) == 0)
2262 g_signal_connect_data (object, signal_spec + 16,
2263 callback, data, NULL,
2265 else if (strncmp (signal_spec, "swapped_object_signal::", 23) == 0 ||
2266 strncmp (signal_spec, "swapped-object-signal::", 23) == 0)
2267 g_signal_connect_object (object, signal_spec + 23,
2270 else if (strncmp (signal_spec, "signal_after::", 14) == 0 ||
2271 strncmp (signal_spec, "signal-after::", 14) == 0)
2272 g_signal_connect_data (object, signal_spec + 14,
2273 callback, data, NULL,
2275 else if (strncmp (signal_spec, "object_signal_after::", 21) == 0 ||
2276 strncmp (signal_spec, "object-signal-after::", 21) == 0)
2277 g_signal_connect_object (object, signal_spec + 21,
2280 else if (strncmp (signal_spec, "swapped_signal_after::", 22) == 0 ||
2281 strncmp (signal_spec, "swapped-signal-after::", 22) == 0)
2282 g_signal_connect_data (object, signal_spec + 22,
2283 callback, data, NULL,
2284 G_CONNECT_SWAPPED | G_CONNECT_AFTER);
2285 else if (strncmp (signal_spec, "swapped_object_signal_after::", 29) == 0 ||
2286 strncmp (signal_spec, "swapped-object-signal-after::", 29) == 0)
2287 g_signal_connect_object (object, signal_spec + 29,
2289 G_CONNECT_SWAPPED | G_CONNECT_AFTER);
2292 g_warning ("%s: invalid signal spec \"%s\"", G_STRFUNC, signal_spec);
2295 signal_spec = va_arg (var_args, gchar*);
2303 * g_object_disconnect: (skip)
2304 * @object: a #GObject
2305 * @signal_spec: the spec for the first signal
2306 * @...: #GCallback for the first signal, followed by data for the first signal,
2307 * followed optionally by more signal spec/callback/data triples,
2310 * A convenience function to disconnect multiple signals at once.
2312 * The signal specs expected by this function have the form
2313 * "any_signal", which means to disconnect any signal with matching
2314 * callback and data, or "any_signal::signal_name", which only
2315 * disconnects the signal named "signal_name".
2318 g_object_disconnect (gpointer _object,
2319 const gchar *signal_spec,
2322 GObject *object = _object;
2325 g_return_if_fail (G_IS_OBJECT (object));
2326 g_return_if_fail (object->ref_count > 0);
2328 va_start (var_args, signal_spec);
2331 GCallback callback = va_arg (var_args, GCallback);
2332 gpointer data = va_arg (var_args, gpointer);
2333 guint sid = 0, detail = 0, mask = 0;
2335 if (strncmp (signal_spec, "any_signal::", 12) == 0 ||
2336 strncmp (signal_spec, "any-signal::", 12) == 0)
2339 mask = G_SIGNAL_MATCH_ID | G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA;
2341 else if (strcmp (signal_spec, "any_signal") == 0 ||
2342 strcmp (signal_spec, "any-signal") == 0)
2345 mask = G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA;
2349 g_warning ("%s: invalid signal spec \"%s\"", G_STRFUNC, signal_spec);
2353 if ((mask & G_SIGNAL_MATCH_ID) &&
2354 !g_signal_parse_name (signal_spec, G_OBJECT_TYPE (object), &sid, &detail, FALSE))
2355 g_warning ("%s: invalid signal name \"%s\"", G_STRFUNC, signal_spec);
2356 else if (!g_signal_handlers_disconnect_matched (object, mask | (detail ? G_SIGNAL_MATCH_DETAIL : 0),
2358 NULL, (gpointer)callback, data))
2359 g_warning ("%s: signal handler %p(%p) is not connected", G_STRFUNC, callback, data);
2360 signal_spec = va_arg (var_args, gchar*);
2371 } weak_refs[1]; /* flexible array */
2375 weak_refs_notify (gpointer data)
2377 WeakRefStack *wstack = data;
2380 for (i = 0; i < wstack->n_weak_refs; i++)
2381 wstack->weak_refs[i].notify (wstack->weak_refs[i].data, wstack->object);
2386 * g_object_weak_ref: (skip)
2387 * @object: #GObject to reference weakly
2388 * @notify: callback to invoke before the object is freed
2389 * @data: extra data to pass to notify
2391 * Adds a weak reference callback to an object. Weak references are
2392 * used for notification when an object is finalized. They are called
2393 * "weak references" because they allow you to safely hold a pointer
2394 * to an object without calling g_object_ref() (g_object_ref() adds a
2395 * strong reference, that is, forces the object to stay alive).
2398 g_object_weak_ref (GObject *object,
2402 WeakRefStack *wstack;
2405 g_return_if_fail (G_IS_OBJECT (object));
2406 g_return_if_fail (notify != NULL);
2407 g_return_if_fail (object->ref_count >= 1);
2409 G_LOCK (weak_refs_mutex);
2410 wstack = g_datalist_id_remove_no_notify (&object->qdata, quark_weak_refs);
2413 i = wstack->n_weak_refs++;
2414 wstack = g_realloc (wstack, sizeof (*wstack) + sizeof (wstack->weak_refs[0]) * i);
2418 wstack = g_renew (WeakRefStack, NULL, 1);
2419 wstack->object = object;
2420 wstack->n_weak_refs = 1;
2423 wstack->weak_refs[i].notify = notify;
2424 wstack->weak_refs[i].data = data;
2425 g_datalist_id_set_data_full (&object->qdata, quark_weak_refs, wstack, weak_refs_notify);
2426 G_UNLOCK (weak_refs_mutex);
2430 * g_object_weak_unref: (skip)
2431 * @object: #GObject to remove a weak reference from
2432 * @notify: callback to search for
2433 * @data: data to search for
2435 * Removes a weak reference callback to an object.
2438 g_object_weak_unref (GObject *object,
2442 WeakRefStack *wstack;
2443 gboolean found_one = FALSE;
2445 g_return_if_fail (G_IS_OBJECT (object));
2446 g_return_if_fail (notify != NULL);
2448 G_LOCK (weak_refs_mutex);
2449 wstack = g_datalist_id_get_data (&object->qdata, quark_weak_refs);
2454 for (i = 0; i < wstack->n_weak_refs; i++)
2455 if (wstack->weak_refs[i].notify == notify &&
2456 wstack->weak_refs[i].data == data)
2459 wstack->n_weak_refs -= 1;
2460 if (i != wstack->n_weak_refs)
2461 wstack->weak_refs[i] = wstack->weak_refs[wstack->n_weak_refs];
2466 G_UNLOCK (weak_refs_mutex);
2468 g_warning ("%s: couldn't find weak ref %p(%p)", G_STRFUNC, notify, data);
2472 * g_object_add_weak_pointer: (skip)
2473 * @object: The object that should be weak referenced.
2474 * @weak_pointer_location: (inout): The memory address of a pointer.
2476 * Adds a weak reference from weak_pointer to @object to indicate that
2477 * the pointer located at @weak_pointer_location is only valid during
2478 * the lifetime of @object. When the @object is finalized,
2479 * @weak_pointer will be set to %NULL.
2482 g_object_add_weak_pointer (GObject *object,
2483 gpointer *weak_pointer_location)
2485 g_return_if_fail (G_IS_OBJECT (object));
2486 g_return_if_fail (weak_pointer_location != NULL);
2488 g_object_weak_ref (object,
2489 (GWeakNotify) g_nullify_pointer,
2490 weak_pointer_location);
2494 * g_object_remove_weak_pointer: (skip)
2495 * @object: The object that is weak referenced.
2496 * @weak_pointer_location: (inout): The memory address of a pointer.
2498 * Removes a weak reference from @object that was previously added
2499 * using g_object_add_weak_pointer(). The @weak_pointer_location has
2500 * to match the one used with g_object_add_weak_pointer().
2503 g_object_remove_weak_pointer (GObject *object,
2504 gpointer *weak_pointer_location)
2506 g_return_if_fail (G_IS_OBJECT (object));
2507 g_return_if_fail (weak_pointer_location != NULL);
2509 g_object_weak_unref (object,
2510 (GWeakNotify) g_nullify_pointer,
2511 weak_pointer_location);
2515 object_floating_flag_handler (GObject *object,
2521 case +1: /* force floating if possible */
2523 oldvalue = g_atomic_pointer_get (&object->qdata);
2524 while (!g_atomic_pointer_compare_and_exchange ((void**) &object->qdata, oldvalue,
2525 (gpointer) ((gsize) oldvalue | OBJECT_FLOATING_FLAG)));
2526 return (gsize) oldvalue & OBJECT_FLOATING_FLAG;
2527 case -1: /* sink if possible */
2529 oldvalue = g_atomic_pointer_get (&object->qdata);
2530 while (!g_atomic_pointer_compare_and_exchange ((void**) &object->qdata, oldvalue,
2531 (gpointer) ((gsize) oldvalue & ~(gsize) OBJECT_FLOATING_FLAG)));
2532 return (gsize) oldvalue & OBJECT_FLOATING_FLAG;
2533 default: /* check floating */
2534 return 0 != ((gsize) g_atomic_pointer_get (&object->qdata) & OBJECT_FLOATING_FLAG);
2539 * g_object_is_floating:
2540 * @object: (type GObject.Object): a #GObject
2542 * Checks whether @object has a <link linkend="floating-ref">floating</link>
2547 * Returns: %TRUE if @object has a floating reference
2550 g_object_is_floating (gpointer _object)
2552 GObject *object = _object;
2553 g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
2554 return floating_flag_handler (object, 0);
2558 * g_object_ref_sink:
2559 * @object: (type GObject.Object): a #GObject
2561 * Increase the reference count of @object, and possibly remove the
2562 * <link linkend="floating-ref">floating</link> reference, if @object
2563 * has a floating reference.
2565 * In other words, if the object is floating, then this call "assumes
2566 * ownership" of the floating reference, converting it to a normal
2567 * reference by clearing the floating flag while leaving the reference
2568 * count unchanged. If the object is not floating, then this call
2569 * adds a new normal reference increasing the reference count by one.
2573 * Returns: (type GObject.Object) (transfer none): @object
2576 g_object_ref_sink (gpointer _object)
2578 GObject *object = _object;
2579 gboolean was_floating;
2580 g_return_val_if_fail (G_IS_OBJECT (object), object);
2581 g_return_val_if_fail (object->ref_count >= 1, object);
2582 g_object_ref (object);
2583 was_floating = floating_flag_handler (object, -1);
2585 g_object_unref (object);
2590 * g_object_force_floating:
2591 * @object: a #GObject
2593 * This function is intended for #GObject implementations to re-enforce a
2594 * <link linkend="floating-ref">floating</link> object reference.
2595 * Doing this is seldom required: all
2596 * #GInitiallyUnowned<!-- -->s are created with a floating reference which
2597 * usually just needs to be sunken by calling g_object_ref_sink().
2602 g_object_force_floating (GObject *object)
2604 g_return_if_fail (G_IS_OBJECT (object));
2605 g_return_if_fail (object->ref_count >= 1);
2607 floating_flag_handler (object, +1);
2612 guint n_toggle_refs;
2614 GToggleNotify notify;
2616 } toggle_refs[1]; /* flexible array */
2620 toggle_refs_notify (GObject *object,
2621 gboolean is_last_ref)
2623 ToggleRefStack tstack, *tstackptr;
2625 G_LOCK (toggle_refs_mutex);
2626 tstackptr = g_datalist_id_get_data (&object->qdata, quark_toggle_refs);
2627 tstack = *tstackptr;
2628 G_UNLOCK (toggle_refs_mutex);
2630 /* Reentrancy here is not as tricky as it seems, because a toggle reference
2631 * will only be notified when there is exactly one of them.
2633 g_assert (tstack.n_toggle_refs == 1);
2634 tstack.toggle_refs[0].notify (tstack.toggle_refs[0].data, tstack.object, is_last_ref);
2638 * g_object_add_toggle_ref: (skip)
2639 * @object: a #GObject
2640 * @notify: a function to call when this reference is the
2641 * last reference to the object, or is no longer
2642 * the last reference.
2643 * @data: data to pass to @notify
2645 * Increases the reference count of the object by one and sets a
2646 * callback to be called when all other references to the object are
2647 * dropped, or when this is already the last reference to the object
2648 * and another reference is established.
2650 * This functionality is intended for binding @object to a proxy
2651 * object managed by another memory manager. This is done with two
2652 * paired references: the strong reference added by
2653 * g_object_add_toggle_ref() and a reverse reference to the proxy
2654 * object which is either a strong reference or weak reference.
2656 * The setup is that when there are no other references to @object,
2657 * only a weak reference is held in the reverse direction from @object
2658 * to the proxy object, but when there are other references held to
2659 * @object, a strong reference is held. The @notify callback is called
2660 * when the reference from @object to the proxy object should be
2661 * <firstterm>toggled</firstterm> from strong to weak (@is_last_ref
2662 * true) or weak to strong (@is_last_ref false).
2664 * Since a (normal) reference must be held to the object before
2665 * calling g_object_add_toggle_ref(), the initial state of the reverse
2666 * link is always strong.
2668 * Multiple toggle references may be added to the same gobject,
2669 * however if there are multiple toggle references to an object, none
2670 * of them will ever be notified until all but one are removed. For
2671 * this reason, you should only ever use a toggle reference if there
2672 * is important state in the proxy object.
2677 g_object_add_toggle_ref (GObject *object,
2678 GToggleNotify notify,
2681 ToggleRefStack *tstack;
2684 g_return_if_fail (G_IS_OBJECT (object));
2685 g_return_if_fail (notify != NULL);
2686 g_return_if_fail (object->ref_count >= 1);
2688 g_object_ref (object);
2690 G_LOCK (toggle_refs_mutex);
2691 tstack = g_datalist_id_remove_no_notify (&object->qdata, quark_toggle_refs);
2694 i = tstack->n_toggle_refs++;
2695 /* allocate i = tstate->n_toggle_refs - 1 positions beyond the 1 declared
2696 * in tstate->toggle_refs */
2697 tstack = g_realloc (tstack, sizeof (*tstack) + sizeof (tstack->toggle_refs[0]) * i);
2701 tstack = g_renew (ToggleRefStack, NULL, 1);
2702 tstack->object = object;
2703 tstack->n_toggle_refs = 1;
2707 /* Set a flag for fast lookup after adding the first toggle reference */
2708 if (tstack->n_toggle_refs == 1)
2709 g_datalist_set_flags (&object->qdata, OBJECT_HAS_TOGGLE_REF_FLAG);
2711 tstack->toggle_refs[i].notify = notify;
2712 tstack->toggle_refs[i].data = data;
2713 g_datalist_id_set_data_full (&object->qdata, quark_toggle_refs, tstack,
2714 (GDestroyNotify)g_free);
2715 G_UNLOCK (toggle_refs_mutex);
2719 * g_object_remove_toggle_ref: (skip)
2720 * @object: a #GObject
2721 * @notify: a function to call when this reference is the
2722 * last reference to the object, or is no longer
2723 * the last reference.
2724 * @data: data to pass to @notify
2726 * Removes a reference added with g_object_add_toggle_ref(). The
2727 * reference count of the object is decreased by one.
2732 g_object_remove_toggle_ref (GObject *object,
2733 GToggleNotify notify,
2736 ToggleRefStack *tstack;
2737 gboolean found_one = FALSE;
2739 g_return_if_fail (G_IS_OBJECT (object));
2740 g_return_if_fail (notify != NULL);
2742 G_LOCK (toggle_refs_mutex);
2743 tstack = g_datalist_id_get_data (&object->qdata, quark_toggle_refs);
2748 for (i = 0; i < tstack->n_toggle_refs; i++)
2749 if (tstack->toggle_refs[i].notify == notify &&
2750 tstack->toggle_refs[i].data == data)
2753 tstack->n_toggle_refs -= 1;
2754 if (i != tstack->n_toggle_refs)
2755 tstack->toggle_refs[i] = tstack->toggle_refs[tstack->n_toggle_refs];
2757 if (tstack->n_toggle_refs == 0)
2758 g_datalist_unset_flags (&object->qdata, OBJECT_HAS_TOGGLE_REF_FLAG);
2763 G_UNLOCK (toggle_refs_mutex);
2766 g_object_unref (object);
2768 g_warning ("%s: couldn't find toggle ref %p(%p)", G_STRFUNC, notify, data);
2773 * @object: (type GObject.Object): a #GObject
2775 * Increases the reference count of @object.
2777 * Returns: (type GObject.Object) (transfer none): the same @object
2780 g_object_ref (gpointer _object)
2782 GObject *object = _object;
2785 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
2786 g_return_val_if_fail (object->ref_count > 0, NULL);
2788 #ifdef G_ENABLE_DEBUG
2789 if (g_trap_object_ref == object)
2791 #endif /* G_ENABLE_DEBUG */
2794 old_val = g_atomic_int_add (&object->ref_count, 1);
2796 if (old_val == 1 && OBJECT_HAS_TOGGLE_REF (object))
2797 toggle_refs_notify (object, FALSE);
2799 TRACE (GOBJECT_OBJECT_REF(object,G_TYPE_FROM_INSTANCE(object),old_val));
2806 * @object: (type GObject.Object): a #GObject
2808 * Decreases the reference count of @object. When its reference count
2809 * drops to 0, the object is finalized (i.e. its memory is freed).
2812 g_object_unref (gpointer _object)
2814 GObject *object = _object;
2817 g_return_if_fail (G_IS_OBJECT (object));
2818 g_return_if_fail (object->ref_count > 0);
2820 #ifdef G_ENABLE_DEBUG
2821 if (g_trap_object_ref == object)
2823 #endif /* G_ENABLE_DEBUG */
2825 /* here we want to atomically do: if (ref_count>1) { ref_count--; return; } */
2826 retry_atomic_decrement1:
2827 old_ref = g_atomic_int_get (&object->ref_count);
2830 /* valid if last 2 refs are owned by this call to unref and the toggle_ref */
2831 gboolean has_toggle_ref = OBJECT_HAS_TOGGLE_REF (object);
2833 if (!g_atomic_int_compare_and_exchange ((int *)&object->ref_count, old_ref, old_ref - 1))
2834 goto retry_atomic_decrement1;
2836 TRACE (GOBJECT_OBJECT_UNREF(object,G_TYPE_FROM_INSTANCE(object),old_ref));
2838 /* if we went from 2->1 we need to notify toggle refs if any */
2839 if (old_ref == 2 && has_toggle_ref) /* The last ref being held in this case is owned by the toggle_ref */
2840 toggle_refs_notify (object, TRUE);
2844 /* we are about tp remove the last reference */
2845 TRACE (GOBJECT_OBJECT_DISPOSE(object,G_TYPE_FROM_INSTANCE(object), 1));
2846 G_OBJECT_GET_CLASS (object)->dispose (object);
2847 TRACE (GOBJECT_OBJECT_DISPOSE_END(object,G_TYPE_FROM_INSTANCE(object), 1));
2849 /* may have been re-referenced meanwhile */
2850 retry_atomic_decrement2:
2851 old_ref = g_atomic_int_get ((int *)&object->ref_count);
2854 /* valid if last 2 refs are owned by this call to unref and the toggle_ref */
2855 gboolean has_toggle_ref = OBJECT_HAS_TOGGLE_REF (object);
2857 if (!g_atomic_int_compare_and_exchange ((int *)&object->ref_count, old_ref, old_ref - 1))
2858 goto retry_atomic_decrement2;
2860 TRACE (GOBJECT_OBJECT_UNREF(object,G_TYPE_FROM_INSTANCE(object),old_ref));
2862 /* if we went from 2->1 we need to notify toggle refs if any */
2863 if (old_ref == 2 && has_toggle_ref) /* The last ref being held in this case is owned by the toggle_ref */
2864 toggle_refs_notify (object, TRUE);
2869 /* we are still in the process of taking away the last ref */
2870 g_datalist_id_set_data (&object->qdata, quark_closure_array, NULL);
2871 g_signal_handlers_destroy (object);
2872 g_datalist_id_set_data (&object->qdata, quark_weak_refs, NULL);
2874 /* decrement the last reference */
2875 old_ref = g_atomic_int_add (&object->ref_count, -1);
2877 TRACE (GOBJECT_OBJECT_UNREF(object,G_TYPE_FROM_INSTANCE(object),old_ref));
2879 /* may have been re-referenced meanwhile */
2880 if (G_LIKELY (old_ref == 1))
2882 TRACE (GOBJECT_OBJECT_FINALIZE(object,G_TYPE_FROM_INSTANCE(object)));
2883 G_OBJECT_GET_CLASS (object)->finalize (object);
2885 TRACE (GOBJECT_OBJECT_FINALIZE_END(object,G_TYPE_FROM_INSTANCE(object)));
2887 #ifdef G_ENABLE_DEBUG
2890 /* catch objects not chaining finalize handlers */
2891 G_LOCK (debug_objects);
2892 g_assert (g_hash_table_lookup (debug_objects_ht, object) == NULL);
2893 G_UNLOCK (debug_objects);
2895 #endif /* G_ENABLE_DEBUG */
2896 g_type_free_instance ((GTypeInstance*) object);
2902 * g_clear_object: (skip)
2903 * @object_ptr: a pointer to a #GObject reference
2905 * Clears a reference to a #GObject.
2907 * @object_ptr must not be %NULL.
2909 * If the reference is %NULL then this function does nothing.
2910 * Otherwise, the reference count of the object is decreased and the
2911 * pointer is set to %NULL.
2913 * This function is threadsafe and modifies the pointer atomically,
2914 * using memory barriers where needed.
2916 * A macro is also included that allows this function to be used without
2921 #undef g_clear_object
2923 g_clear_object (volatile GObject **object_ptr)
2925 gpointer *ptr = (gpointer) object_ptr;
2928 /* This is a little frustrating.
2929 * Would be nice to have an atomic exchange (with no compare).
2932 old = g_atomic_pointer_get (ptr);
2933 while G_UNLIKELY (!g_atomic_pointer_compare_and_exchange (ptr, old, NULL));
2936 g_object_unref (old);
2940 * g_object_get_qdata:
2941 * @object: The GObject to get a stored user data pointer from
2942 * @quark: A #GQuark, naming the user data pointer
2944 * This function gets back user data pointers stored via
2945 * g_object_set_qdata().
2947 * Returns: (transfer none): The user data pointer set, or %NULL
2950 g_object_get_qdata (GObject *object,
2953 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
2955 return quark ? g_datalist_id_get_data (&object->qdata, quark) : NULL;
2959 * g_object_set_qdata: (skip)
2960 * @object: The GObject to set store a user data pointer
2961 * @quark: A #GQuark, naming the user data pointer
2962 * @data: An opaque user data pointer
2964 * This sets an opaque, named pointer on an object.
2965 * The name is specified through a #GQuark (retrived e.g. via
2966 * g_quark_from_static_string()), and the pointer
2967 * can be gotten back from the @object with g_object_get_qdata()
2968 * until the @object is finalized.
2969 * Setting a previously set user data pointer, overrides (frees)
2970 * the old pointer set, using #NULL as pointer essentially
2971 * removes the data stored.
2974 g_object_set_qdata (GObject *object,
2978 g_return_if_fail (G_IS_OBJECT (object));
2979 g_return_if_fail (quark > 0);
2981 g_datalist_id_set_data (&object->qdata, quark, data);
2985 * g_object_set_qdata_full: (skip)
2986 * @object: The GObject to set store a user data pointer
2987 * @quark: A #GQuark, naming the user data pointer
2988 * @data: An opaque user data pointer
2989 * @destroy: Function to invoke with @data as argument, when @data
2992 * This function works like g_object_set_qdata(), but in addition,
2993 * a void (*destroy) (gpointer) function may be specified which is
2994 * called with @data as argument when the @object is finalized, or
2995 * the data is being overwritten by a call to g_object_set_qdata()
2996 * with the same @quark.
2999 g_object_set_qdata_full (GObject *object,
3002 GDestroyNotify destroy)
3004 g_return_if_fail (G_IS_OBJECT (object));
3005 g_return_if_fail (quark > 0);
3007 g_datalist_id_set_data_full (&object->qdata, quark, data,
3008 data ? destroy : (GDestroyNotify) NULL);
3012 * g_object_steal_qdata:
3013 * @object: The GObject to get a stored user data pointer from
3014 * @quark: A #GQuark, naming the user data pointer
3016 * This function gets back user data pointers stored via
3017 * g_object_set_qdata() and removes the @data from object
3018 * without invoking its destroy() function (if any was
3020 * Usually, calling this function is only required to update
3021 * user data pointers with a destroy notifier, for example:
3024 * object_add_to_user_list (GObject *object,
3025 * const gchar *new_string)
3027 * // the quark, naming the object data
3028 * GQuark quark_string_list = g_quark_from_static_string ("my-string-list");
3029 * // retrive the old string list
3030 * GList *list = g_object_steal_qdata (object, quark_string_list);
3032 * // prepend new string
3033 * list = g_list_prepend (list, g_strdup (new_string));
3034 * // this changed 'list', so we need to set it again
3035 * g_object_set_qdata_full (object, quark_string_list, list, free_string_list);
3038 * free_string_list (gpointer data)
3040 * GList *node, *list = data;
3042 * for (node = list; node; node = node->next)
3043 * g_free (node->data);
3044 * g_list_free (list);
3047 * Using g_object_get_qdata() in the above example, instead of
3048 * g_object_steal_qdata() would have left the destroy function set,
3049 * and thus the partial string list would have been freed upon
3050 * g_object_set_qdata_full().
3052 * Returns: (transfer full): The user data pointer set, or %NULL
3055 g_object_steal_qdata (GObject *object,
3058 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3059 g_return_val_if_fail (quark > 0, NULL);
3061 return g_datalist_id_remove_no_notify (&object->qdata, quark);
3065 * g_object_get_data:
3066 * @object: #GObject containing the associations
3067 * @key: name of the key for that association
3069 * Gets a named field from the objects table of associations (see g_object_set_data()).
3071 * Returns: (transfer none): the data if found, or %NULL if no such data exists.
3074 g_object_get_data (GObject *object,
3077 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3078 g_return_val_if_fail (key != NULL, NULL);
3080 return g_datalist_get_data (&object->qdata, key);
3084 * g_object_set_data:
3085 * @object: #GObject containing the associations.
3086 * @key: name of the key
3087 * @data: data to associate with that key
3089 * Each object carries around a table of associations from
3090 * strings to pointers. This function lets you set an association.
3092 * If the object already had an association with that name,
3093 * the old association will be destroyed.
3096 g_object_set_data (GObject *object,
3100 g_return_if_fail (G_IS_OBJECT (object));
3101 g_return_if_fail (key != NULL);
3103 g_datalist_id_set_data (&object->qdata, g_quark_from_string (key), data);
3107 * g_object_set_data_full: (skip)
3108 * @object: #GObject containing the associations
3109 * @key: name of the key
3110 * @data: data to associate with that key
3111 * @destroy: function to call when the association is destroyed
3113 * Like g_object_set_data() except it adds notification
3114 * for when the association is destroyed, either by setting it
3115 * to a different value or when the object is destroyed.
3117 * Note that the @destroy callback is not called if @data is %NULL.
3120 g_object_set_data_full (GObject *object,
3123 GDestroyNotify destroy)
3125 g_return_if_fail (G_IS_OBJECT (object));
3126 g_return_if_fail (key != NULL);
3128 g_datalist_id_set_data_full (&object->qdata, g_quark_from_string (key), data,
3129 data ? destroy : (GDestroyNotify) NULL);
3133 * g_object_steal_data:
3134 * @object: #GObject containing the associations
3135 * @key: name of the key
3137 * Remove a specified datum from the object's data associations,
3138 * without invoking the association's destroy handler.
3140 * Returns: (transfer full): the data if found, or %NULL if no such data exists.
3143 g_object_steal_data (GObject *object,
3148 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3149 g_return_val_if_fail (key != NULL, NULL);
3151 quark = g_quark_try_string (key);
3153 return quark ? g_datalist_id_remove_no_notify (&object->qdata, quark) : NULL;
3157 g_value_object_init (GValue *value)
3159 value->data[0].v_pointer = NULL;
3163 g_value_object_free_value (GValue *value)
3165 if (value->data[0].v_pointer)
3166 g_object_unref (value->data[0].v_pointer);
3170 g_value_object_copy_value (const GValue *src_value,
3173 if (src_value->data[0].v_pointer)
3174 dest_value->data[0].v_pointer = g_object_ref (src_value->data[0].v_pointer);
3176 dest_value->data[0].v_pointer = NULL;
3180 g_value_object_transform_value (const GValue *src_value,
3183 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)))
3184 dest_value->data[0].v_pointer = g_object_ref (src_value->data[0].v_pointer);
3186 dest_value->data[0].v_pointer = NULL;
3190 g_value_object_peek_pointer (const GValue *value)
3192 return value->data[0].v_pointer;
3196 g_value_object_collect_value (GValue *value,
3197 guint n_collect_values,
3198 GTypeCValue *collect_values,
3199 guint collect_flags)
3201 if (collect_values[0].v_pointer)
3203 GObject *object = collect_values[0].v_pointer;
3205 if (object->g_type_instance.g_class == NULL)
3206 return g_strconcat ("invalid unclassed object pointer for value type `",
3207 G_VALUE_TYPE_NAME (value),
3210 else if (!g_value_type_compatible (G_OBJECT_TYPE (object), G_VALUE_TYPE (value)))
3211 return g_strconcat ("invalid object type `",
3212 G_OBJECT_TYPE_NAME (object),
3213 "' for value type `",
3214 G_VALUE_TYPE_NAME (value),
3217 /* never honour G_VALUE_NOCOPY_CONTENTS for ref-counted types */
3218 value->data[0].v_pointer = g_object_ref (object);
3221 value->data[0].v_pointer = NULL;
3227 g_value_object_lcopy_value (const GValue *value,
3228 guint n_collect_values,
3229 GTypeCValue *collect_values,
3230 guint collect_flags)
3232 GObject **object_p = collect_values[0].v_pointer;
3235 return g_strdup_printf ("value location for `%s' passed as NULL", G_VALUE_TYPE_NAME (value));
3237 if (!value->data[0].v_pointer)
3239 else if (collect_flags & G_VALUE_NOCOPY_CONTENTS)
3240 *object_p = value->data[0].v_pointer;
3242 *object_p = g_object_ref (value->data[0].v_pointer);
3248 * g_value_set_object:
3249 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
3250 * @v_object: (type GObject.Object) (allow-none): object value to be set
3252 * Set the contents of a %G_TYPE_OBJECT derived #GValue to @v_object.
3254 * g_value_set_object() increases the reference count of @v_object
3255 * (the #GValue holds a reference to @v_object). If you do not wish
3256 * to increase the reference count of the object (i.e. you wish to
3257 * pass your current reference to the #GValue because you no longer
3258 * need it), use g_value_take_object() instead.
3260 * It is important that your #GValue holds a reference to @v_object (either its
3261 * own, or one it has taken) to ensure that the object won't be destroyed while
3262 * the #GValue still exists).
3265 g_value_set_object (GValue *value,
3270 g_return_if_fail (G_VALUE_HOLDS_OBJECT (value));
3272 old = value->data[0].v_pointer;
3276 g_return_if_fail (G_IS_OBJECT (v_object));
3277 g_return_if_fail (g_value_type_compatible (G_OBJECT_TYPE (v_object), G_VALUE_TYPE (value)));
3279 value->data[0].v_pointer = v_object;
3280 g_object_ref (value->data[0].v_pointer);
3283 value->data[0].v_pointer = NULL;
3286 g_object_unref (old);
3290 * g_value_set_object_take_ownership: (skip)
3291 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
3292 * @v_object: (allow-none): object value to be set
3294 * This is an internal function introduced mainly for C marshallers.
3296 * Deprecated: 2.4: Use g_value_take_object() instead.
3299 g_value_set_object_take_ownership (GValue *value,
3302 g_value_take_object (value, v_object);
3306 * g_value_take_object: (skip)
3307 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
3308 * @v_object: (allow-none): object value to be set
3310 * Sets the contents of a %G_TYPE_OBJECT derived #GValue to @v_object
3311 * and takes over the ownership of the callers reference to @v_object;
3312 * the caller doesn't have to unref it any more (i.e. the reference
3313 * count of the object is not increased).
3315 * If you want the #GValue to hold its own reference to @v_object, use
3316 * g_value_set_object() instead.
3321 g_value_take_object (GValue *value,
3324 g_return_if_fail (G_VALUE_HOLDS_OBJECT (value));
3326 if (value->data[0].v_pointer)
3328 g_object_unref (value->data[0].v_pointer);
3329 value->data[0].v_pointer = NULL;
3334 g_return_if_fail (G_IS_OBJECT (v_object));
3335 g_return_if_fail (g_value_type_compatible (G_OBJECT_TYPE (v_object), G_VALUE_TYPE (value)));
3337 value->data[0].v_pointer = v_object; /* we take over the reference count */
3342 * g_value_get_object:
3343 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
3345 * Get the contents of a %G_TYPE_OBJECT derived #GValue.
3347 * Returns: (type GObject.Object) (transfer none): object contents of @value
3350 g_value_get_object (const GValue *value)
3352 g_return_val_if_fail (G_VALUE_HOLDS_OBJECT (value), NULL);
3354 return value->data[0].v_pointer;
3358 * g_value_dup_object:
3359 * @value: a valid #GValue whose type is derived from %G_TYPE_OBJECT
3361 * Get the contents of a %G_TYPE_OBJECT derived #GValue, increasing
3362 * its reference count. If the contents of the #GValue are %NULL, then
3363 * %NULL will be returned.
3365 * Returns: (type GObject.Object) (transfer full): object content of @value,
3366 * should be unreferenced when no longer needed.
3369 g_value_dup_object (const GValue *value)
3371 g_return_val_if_fail (G_VALUE_HOLDS_OBJECT (value), NULL);
3373 return value->data[0].v_pointer ? g_object_ref (value->data[0].v_pointer) : NULL;
3377 * g_signal_connect_object: (skip)
3378 * @instance: the instance to connect to.
3379 * @detailed_signal: a string of the form "signal-name::detail".
3380 * @c_handler: the #GCallback to connect.
3381 * @gobject: the object to pass as data to @c_handler.
3382 * @connect_flags: a combination of #GConnectFlags.
3384 * This is similar to g_signal_connect_data(), but uses a closure which
3385 * ensures that the @gobject stays alive during the call to @c_handler
3386 * by temporarily adding a reference count to @gobject.
3388 * Note that there is a bug in GObject that makes this function
3389 * much less useful than it might seem otherwise. Once @gobject is
3390 * disposed, the callback will no longer be called, but, the signal
3391 * handler is <emphasis>not</emphasis> currently disconnected. If the
3392 * @instance is itself being freed at the same time than this doesn't
3393 * matter, since the signal will automatically be removed, but
3394 * if @instance persists, then the signal handler will leak. You
3395 * should not remove the signal yourself because in a future versions of
3396 * GObject, the handler <emphasis>will</emphasis> automatically
3399 * It's possible to work around this problem in a way that will
3400 * continue to work with future versions of GObject by checking
3401 * that the signal handler is still connected before disconnected it:
3402 * <informalexample><programlisting>
3403 * if (g_signal_handler_is_connected (instance, id))
3404 * g_signal_handler_disconnect (instance, id);
3405 * </programlisting></informalexample>
3407 * Returns: the handler id.
3410 g_signal_connect_object (gpointer instance,
3411 const gchar *detailed_signal,
3412 GCallback c_handler,
3414 GConnectFlags connect_flags)
3416 g_return_val_if_fail (G_TYPE_CHECK_INSTANCE (instance), 0);
3417 g_return_val_if_fail (detailed_signal != NULL, 0);
3418 g_return_val_if_fail (c_handler != NULL, 0);
3424 g_return_val_if_fail (G_IS_OBJECT (gobject), 0);
3426 closure = ((connect_flags & G_CONNECT_SWAPPED) ? g_cclosure_new_object_swap : g_cclosure_new_object) (c_handler, gobject);
3428 return g_signal_connect_closure (instance, detailed_signal, closure, connect_flags & G_CONNECT_AFTER);
3431 return g_signal_connect_data (instance, detailed_signal, c_handler, NULL, NULL, connect_flags);
3437 GClosure *closures[1]; /* flexible array */
3439 /* don't change this structure without supplying an accessor for
3440 * watched closures, e.g.:
3441 * GSList* g_object_list_watched_closures (GObject *object)
3444 * g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3445 * carray = g_object_get_data (object, "GObject-closure-array");
3448 * GSList *slist = NULL;
3450 * for (i = 0; i < carray->n_closures; i++)
3451 * slist = g_slist_prepend (slist, carray->closures[i]);
3459 object_remove_closure (gpointer data,
3462 GObject *object = data;
3466 G_LOCK (closure_array_mutex);
3467 carray = g_object_get_qdata (object, quark_closure_array);
3468 for (i = 0; i < carray->n_closures; i++)
3469 if (carray->closures[i] == closure)
3471 carray->n_closures--;
3472 if (i < carray->n_closures)
3473 carray->closures[i] = carray->closures[carray->n_closures];
3474 G_UNLOCK (closure_array_mutex);
3477 G_UNLOCK (closure_array_mutex);
3478 g_assert_not_reached ();
3482 destroy_closure_array (gpointer data)
3484 CArray *carray = data;
3485 GObject *object = carray->object;
3486 guint i, n = carray->n_closures;
3488 for (i = 0; i < n; i++)
3490 GClosure *closure = carray->closures[i];
3492 /* removing object_remove_closure() upfront is probably faster than
3493 * letting it fiddle with quark_closure_array which is empty anyways
3495 g_closure_remove_invalidate_notifier (closure, object, object_remove_closure);
3496 g_closure_invalidate (closure);
3502 * g_object_watch_closure:
3503 * @object: GObject restricting lifetime of @closure
3504 * @closure: GClosure to watch
3506 * This function essentially limits the life time of the @closure to
3507 * the life time of the object. That is, when the object is finalized,
3508 * the @closure is invalidated by calling g_closure_invalidate() on
3509 * it, in order to prevent invocations of the closure with a finalized
3510 * (nonexisting) object. Also, g_object_ref() and g_object_unref() are
3511 * added as marshal guards to the @closure, to ensure that an extra
3512 * reference count is held on @object during invocation of the
3513 * @closure. Usually, this function will be called on closures that
3514 * use this @object as closure data.
3517 g_object_watch_closure (GObject *object,
3523 g_return_if_fail (G_IS_OBJECT (object));
3524 g_return_if_fail (closure != NULL);
3525 g_return_if_fail (closure->is_invalid == FALSE);
3526 g_return_if_fail (closure->in_marshal == FALSE);
3527 g_return_if_fail (object->ref_count > 0); /* this doesn't work on finalizing objects */
3529 g_closure_add_invalidate_notifier (closure, object, object_remove_closure);
3530 g_closure_add_marshal_guards (closure,
3531 object, (GClosureNotify) g_object_ref,
3532 object, (GClosureNotify) g_object_unref);
3533 G_LOCK (closure_array_mutex);
3534 carray = g_datalist_id_remove_no_notify (&object->qdata, quark_closure_array);
3537 carray = g_renew (CArray, NULL, 1);
3538 carray->object = object;
3539 carray->n_closures = 1;
3544 i = carray->n_closures++;
3545 carray = g_realloc (carray, sizeof (*carray) + sizeof (carray->closures[0]) * i);
3547 carray->closures[i] = closure;
3548 g_datalist_id_set_data_full (&object->qdata, quark_closure_array, carray, destroy_closure_array);
3549 G_UNLOCK (closure_array_mutex);
3553 * g_closure_new_object:
3554 * @sizeof_closure: the size of the structure to allocate, must be at least
3555 * <literal>sizeof (GClosure)</literal>
3556 * @object: a #GObject pointer to store in the @data field of the newly
3557 * allocated #GClosure
3559 * A variant of g_closure_new_simple() which stores @object in the
3560 * @data field of the closure and calls g_object_watch_closure() on
3561 * @object and the created closure. This function is mainly useful
3562 * when implementing new types of closures.
3564 * Returns: (transfer full): a newly allocated #GClosure
3567 g_closure_new_object (guint sizeof_closure,
3572 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3573 g_return_val_if_fail (object->ref_count > 0, NULL); /* this doesn't work on finalizing objects */
3575 closure = g_closure_new_simple (sizeof_closure, object);
3576 g_object_watch_closure (object, closure);
3582 * g_cclosure_new_object: (skip)
3583 * @callback_func: the function to invoke
3584 * @object: a #GObject pointer to pass to @callback_func
3586 * A variant of g_cclosure_new() which uses @object as @user_data and
3587 * calls g_object_watch_closure() on @object and the created
3588 * closure. This function is useful when you have a callback closely
3589 * associated with a #GObject, and want the callback to no longer run
3590 * after the object is is freed.
3592 * Returns: a new #GCClosure
3595 g_cclosure_new_object (GCallback callback_func,
3600 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3601 g_return_val_if_fail (object->ref_count > 0, NULL); /* this doesn't work on finalizing objects */
3602 g_return_val_if_fail (callback_func != NULL, NULL);
3604 closure = g_cclosure_new (callback_func, object, NULL);
3605 g_object_watch_closure (object, closure);
3611 * g_cclosure_new_object_swap: (skip)
3612 * @callback_func: the function to invoke
3613 * @object: a #GObject pointer to pass to @callback_func
3615 * A variant of g_cclosure_new_swap() which uses @object as @user_data
3616 * and calls g_object_watch_closure() on @object and the created
3617 * closure. This function is useful when you have a callback closely
3618 * associated with a #GObject, and want the callback to no longer run
3619 * after the object is is freed.
3621 * Returns: a new #GCClosure
3624 g_cclosure_new_object_swap (GCallback callback_func,
3629 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3630 g_return_val_if_fail (object->ref_count > 0, NULL); /* this doesn't work on finalizing objects */
3631 g_return_val_if_fail (callback_func != NULL, NULL);
3633 closure = g_cclosure_new_swap (callback_func, object, NULL);
3634 g_object_watch_closure (object, closure);
3640 g_object_compat_control (gsize what,
3646 case 1: /* floating base type */
3647 return G_TYPE_INITIALLY_UNOWNED;
3648 case 2: /* FIXME: remove this once GLib/Gtk+ break ABI again */
3649 floating_flag_handler = (guint(*)(GObject*,gint)) data;
3651 case 3: /* FIXME: remove this once GLib/Gtk+ break ABI again */
3653 *pp = floating_flag_handler;
3660 G_DEFINE_TYPE (GInitiallyUnowned, g_initially_unowned, G_TYPE_OBJECT);
3663 g_initially_unowned_init (GInitiallyUnowned *object)
3665 g_object_force_floating (object);
3669 g_initially_unowned_class_init (GInitiallyUnownedClass *klass)