Add unit tests for some more methods
[glib.git] / gobject / gobject.c
blob58554c3372a41e197c3a0889888daa5d04b85a3f
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.
24 #include "config.h"
26 #include <string.h>
27 #include <signal.h>
29 #include "glib/gdatasetprivate.h"
31 #include "gobject.h"
32 #include "gvaluecollector.h"
33 #include "gsignal.h"
34 #include "gparamspecs.h"
35 #include "gvaluetypes.h"
36 #include "gobjectalias.h"
38 /* This should be included after gobjectalias.h (or pltcheck.sh will fail) */
39 #include "gobjectnotifyqueue.c"
42 /**
43 * SECTION:objects
44 * @short_description: The base object type
45 * @see_also: #GParamSpecObject, g_param_spec_object()
46 * @title: The Base Object Type
48 * GObject is the fundamental type providing the common attributes and
49 * methods for all object types in GTK+, Pango and other libraries
50 * based on GObject. The GObject class provides methods for object
51 * construction and destruction, property access methods, and signal
52 * support. Signals are described in detail in <xref
53 * linkend="gobject-Signals"/>.
55 * <para id="floating-ref">
56 * #GInitiallyUnowned is derived from #GObject. The only difference between
57 * the two is that the initial reference of a #GInitiallyUnowned is flagged
58 * as a <firstterm>floating</firstterm> reference.
59 * This means that it is not specifically claimed to be "owned" by
60 * any code portion. The main motivation for providing floating references is
61 * C convenience. In particular, it allows code to be written as:
62 * |[
63 * container = create_container();
64 * container_add_child (container, create_child());
65 * ]|
66 * If <function>container_add_child()</function> will g_object_ref_sink() the
67 * passed in child, no reference of the newly created child is leaked.
68 * Without floating references, <function>container_add_child()</function>
69 * can only g_object_ref() the new child, so to implement this code without
70 * reference leaks, it would have to be written as:
71 * |[
72 * Child *child;
73 * container = create_container();
74 * child = create_child();
75 * container_add_child (container, child);
76 * g_object_unref (child);
77 * ]|
78 * The floating reference can be converted into
79 * an ordinary reference by calling g_object_ref_sink().
80 * For already sunken objects (objects that don't have a floating reference
81 * anymore), g_object_ref_sink() is equivalent to g_object_ref() and returns
82 * a new reference.
83 * Since floating references are useful almost exclusively for C convenience,
84 * language bindings that provide automated reference and memory ownership
85 * maintenance (such as smart pointers or garbage collection) therefore don't
86 * need to expose floating references in their API.
87 * </para>
89 * Some object implementations may need to save an objects floating state
90 * across certain code portions (an example is #GtkMenu), to achive this, the
91 * following sequence can be used:
93 * |[
94 * // save floating state
95 * gboolean was_floating = g_object_is_floating (object);
96 * g_object_ref_sink (object);
97 * // protected code portion
98 * ...;
99 * // restore floating state
100 * if (was_floating)
101 * g_object_force_floating (object);
102 * g_obejct_unref (object); // release previously acquired reference
103 * ]|
107 /* --- macros --- */
108 #define PARAM_SPEC_PARAM_ID(pspec) ((pspec)->param_id)
109 #define PARAM_SPEC_SET_PARAM_ID(pspec, id) ((pspec)->param_id = (id))
111 #define OBJECT_HAS_TOGGLE_REF_FLAG 0x1
112 #define OBJECT_HAS_TOGGLE_REF(object) \
113 ((G_DATALIST_GET_FLAGS (&(object)->qdata) & OBJECT_HAS_TOGGLE_REF_FLAG) != 0)
114 #define OBJECT_FLOATING_FLAG 0x2
116 #define CLASS_HAS_PROPS_FLAG 0x1
117 #define CLASS_HAS_PROPS(class) \
118 ((class)->flags & CLASS_HAS_PROPS_FLAG)
119 #define CLASS_HAS_CUSTOM_CONSTRUCTOR(class) \
120 ((class)->constructor != g_object_constructor)
122 #define CLASS_HAS_DERIVED_CLASS_FLAG 0x2
123 #define CLASS_HAS_DERIVED_CLASS(class) \
124 ((class)->flags & CLASS_HAS_DERIVED_CLASS_FLAG)
126 /* --- signals --- */
127 enum {
128 NOTIFY,
129 LAST_SIGNAL
133 /* --- properties --- */
134 enum {
135 PROP_NONE
139 /* --- prototypes --- */
140 static void g_object_base_class_init (GObjectClass *class);
141 static void g_object_base_class_finalize (GObjectClass *class);
142 static void g_object_do_class_init (GObjectClass *class);
143 static void g_object_init (GObject *object,
144 GObjectClass *class);
145 static GObject* g_object_constructor (GType type,
146 guint n_construct_properties,
147 GObjectConstructParam *construct_params);
148 static void g_object_real_dispose (GObject *object);
149 static void g_object_finalize (GObject *object);
150 static void g_object_do_set_property (GObject *object,
151 guint property_id,
152 const GValue *value,
153 GParamSpec *pspec);
154 static void g_object_do_get_property (GObject *object,
155 guint property_id,
156 GValue *value,
157 GParamSpec *pspec);
158 static void g_value_object_init (GValue *value);
159 static void g_value_object_free_value (GValue *value);
160 static void g_value_object_copy_value (const GValue *src_value,
161 GValue *dest_value);
162 static void g_value_object_transform_value (const GValue *src_value,
163 GValue *dest_value);
164 static gpointer g_value_object_peek_pointer (const GValue *value);
165 static gchar* g_value_object_collect_value (GValue *value,
166 guint n_collect_values,
167 GTypeCValue *collect_values,
168 guint collect_flags);
169 static gchar* g_value_object_lcopy_value (const GValue *value,
170 guint n_collect_values,
171 GTypeCValue *collect_values,
172 guint collect_flags);
173 static void g_object_dispatch_properties_changed (GObject *object,
174 guint n_pspecs,
175 GParamSpec **pspecs);
176 static inline void object_get_property (GObject *object,
177 GParamSpec *pspec,
178 GValue *value);
179 static inline void object_set_property (GObject *object,
180 GParamSpec *pspec,
181 const GValue *value,
182 GObjectNotifyQueue *nqueue);
183 static guint object_floating_flag_handler (GObject *object,
184 gint job);
186 static void object_interface_check_properties (gpointer func_data,
187 gpointer g_iface);
190 /* --- variables --- */
191 static GQuark quark_closure_array = 0;
192 static GQuark quark_weak_refs = 0;
193 static GQuark quark_toggle_refs = 0;
194 static GParamSpecPool *pspec_pool = NULL;
195 static GObjectNotifyContext property_notify_context = { 0, };
196 static gulong gobject_signals[LAST_SIGNAL] = { 0, };
197 static guint (*floating_flag_handler) (GObject*, gint) = object_floating_flag_handler;
198 G_LOCK_DEFINE_STATIC (construction_mutex);
199 static GSList *construction_objects = NULL;
201 /* --- functions --- */
202 #ifdef G_ENABLE_DEBUG
203 #define IF_DEBUG(debug_type) if (_g_type_debug_flags & G_TYPE_DEBUG_ ## debug_type)
204 G_LOCK_DEFINE_STATIC (debug_objects);
205 static volatile GObject *g_trap_object_ref = NULL;
206 static guint debug_objects_count = 0;
207 static GHashTable *debug_objects_ht = NULL;
209 static void
210 debug_objects_foreach (gpointer key,
211 gpointer value,
212 gpointer user_data)
214 GObject *object = value;
216 g_message ("[%p] stale %s\tref_count=%u",
217 object,
218 G_OBJECT_TYPE_NAME (object),
219 object->ref_count);
222 static void
223 debug_objects_atexit (void)
225 IF_DEBUG (OBJECTS)
227 G_LOCK (debug_objects);
228 g_message ("stale GObjects: %u", debug_objects_count);
229 g_hash_table_foreach (debug_objects_ht, debug_objects_foreach, NULL);
230 G_UNLOCK (debug_objects);
233 #endif /* G_ENABLE_DEBUG */
235 void
236 g_object_type_init (void)
238 static gboolean initialized = FALSE;
239 static const GTypeFundamentalInfo finfo = {
240 G_TYPE_FLAG_CLASSED | G_TYPE_FLAG_INSTANTIATABLE | G_TYPE_FLAG_DERIVABLE | G_TYPE_FLAG_DEEP_DERIVABLE,
242 static GTypeInfo info = {
243 sizeof (GObjectClass),
244 (GBaseInitFunc) g_object_base_class_init,
245 (GBaseFinalizeFunc) g_object_base_class_finalize,
246 (GClassInitFunc) g_object_do_class_init,
247 NULL /* class_destroy */,
248 NULL /* class_data */,
249 sizeof (GObject),
250 0 /* n_preallocs */,
251 (GInstanceInitFunc) g_object_init,
252 NULL, /* value_table */
254 static const GTypeValueTable value_table = {
255 g_value_object_init, /* value_init */
256 g_value_object_free_value, /* value_free */
257 g_value_object_copy_value, /* value_copy */
258 g_value_object_peek_pointer, /* value_peek_pointer */
259 "p", /* collect_format */
260 g_value_object_collect_value, /* collect_value */
261 "p", /* lcopy_format */
262 g_value_object_lcopy_value, /* lcopy_value */
264 GType type;
266 g_return_if_fail (initialized == FALSE);
267 initialized = TRUE;
269 /* G_TYPE_OBJECT
271 info.value_table = &value_table;
272 type = g_type_register_fundamental (G_TYPE_OBJECT, g_intern_static_string ("GObject"), &info, &finfo, 0);
273 g_assert (type == G_TYPE_OBJECT);
274 g_value_register_transform_func (G_TYPE_OBJECT, G_TYPE_OBJECT, g_value_object_transform_value);
276 #ifdef G_ENABLE_DEBUG
277 IF_DEBUG (OBJECTS)
279 debug_objects_ht = g_hash_table_new (g_direct_hash, NULL);
280 g_atexit (debug_objects_atexit);
282 #endif /* G_ENABLE_DEBUG */
285 static void
286 g_object_base_class_init (GObjectClass *class)
288 GObjectClass *pclass = g_type_class_peek_parent (class);
290 /* Don't inherit HAS_DERIVED_CLASS flag from parent class */
291 class->flags &= ~CLASS_HAS_DERIVED_CLASS_FLAG;
293 if (pclass)
294 pclass->flags |= CLASS_HAS_DERIVED_CLASS_FLAG;
296 /* reset instance specific fields and methods that don't get inherited */
297 class->construct_properties = pclass ? g_slist_copy (pclass->construct_properties) : NULL;
298 class->get_property = NULL;
299 class->set_property = NULL;
302 static void
303 g_object_base_class_finalize (GObjectClass *class)
305 GList *list, *node;
307 _g_signals_destroy (G_OBJECT_CLASS_TYPE (class));
309 g_slist_free (class->construct_properties);
310 class->construct_properties = NULL;
311 list = g_param_spec_pool_list_owned (pspec_pool, G_OBJECT_CLASS_TYPE (class));
312 for (node = list; node; node = node->next)
314 GParamSpec *pspec = node->data;
316 g_param_spec_pool_remove (pspec_pool, pspec);
317 PARAM_SPEC_SET_PARAM_ID (pspec, 0);
318 g_param_spec_unref (pspec);
320 g_list_free (list);
323 static void
324 g_object_notify_dispatcher (GObject *object,
325 guint n_pspecs,
326 GParamSpec **pspecs)
328 G_OBJECT_GET_CLASS (object)->dispatch_properties_changed (object, n_pspecs, pspecs);
331 static void
332 g_object_do_class_init (GObjectClass *class)
334 /* read the comment about typedef struct CArray; on why not to change this quark */
335 quark_closure_array = g_quark_from_static_string ("GObject-closure-array");
337 quark_weak_refs = g_quark_from_static_string ("GObject-weak-references");
338 quark_toggle_refs = g_quark_from_static_string ("GObject-toggle-references");
339 pspec_pool = g_param_spec_pool_new (TRUE);
340 property_notify_context.quark_notify_queue = g_quark_from_static_string ("GObject-notify-queue");
341 property_notify_context.dispatcher = g_object_notify_dispatcher;
343 class->constructor = g_object_constructor;
344 class->set_property = g_object_do_set_property;
345 class->get_property = g_object_do_get_property;
346 class->dispose = g_object_real_dispose;
347 class->finalize = g_object_finalize;
348 class->dispatch_properties_changed = g_object_dispatch_properties_changed;
349 class->notify = NULL;
352 * GObject::notify:
353 * @gobject: the object which received the signal.
354 * @pspec: the #GParamSpec of the property which changed.
356 * The notify signal is emitted on an object when one of its
357 * properties has been changed. Note that getting this signal
358 * doesn't guarantee that the value of the property has actually
359 * changed, it may also be emitted when the setter for the property
360 * is called to reinstate the previous value.
362 * This signal is typically used to obtain change notification for a
363 * single property, by specifying the property name as a detail in the
364 * g_signal_connect() call, like this:
365 * |[
366 * g_signal_connect (text_view->buffer, "notify::paste-target-list",
367 * G_CALLBACK (gtk_text_view_target_list_notify),
368 * text_view)
369 * ]|
370 * It is important to note that you must use
371 * <link linkend="canonical-parameter-name">canonical</link> parameter names as
372 * detail strings for the notify signal.
374 gobject_signals[NOTIFY] =
375 g_signal_new (g_intern_static_string ("notify"),
376 G_TYPE_FROM_CLASS (class),
377 G_SIGNAL_RUN_FIRST | G_SIGNAL_NO_RECURSE | G_SIGNAL_DETAILED | G_SIGNAL_NO_HOOKS | G_SIGNAL_ACTION,
378 G_STRUCT_OFFSET (GObjectClass, notify),
379 NULL, NULL,
380 g_cclosure_marshal_VOID__PARAM,
381 G_TYPE_NONE,
382 1, G_TYPE_PARAM);
384 /* Install a check function that we'll use to verify that classes that
385 * implement an interface implement all properties for that interface
387 g_type_add_interface_check (NULL, object_interface_check_properties);
390 static void
391 install_property_internal (GType g_type,
392 guint property_id,
393 GParamSpec *pspec)
395 if (g_param_spec_pool_lookup (pspec_pool, pspec->name, g_type, FALSE))
397 g_warning ("When installing property: type `%s' already has a property named `%s'",
398 g_type_name (g_type),
399 pspec->name);
400 return;
403 g_param_spec_ref (pspec);
404 g_param_spec_sink (pspec);
405 PARAM_SPEC_SET_PARAM_ID (pspec, property_id);
406 g_param_spec_pool_insert (pspec_pool, pspec, g_type);
410 * g_object_class_install_property:
411 * @oclass: a #GObjectClass
412 * @property_id: the id for the new property
413 * @pspec: the #GParamSpec for the new property
415 * Installs a new property. This is usually done in the class initializer.
417 * Note that it is possible to redefine a property in a derived class,
418 * by installing a property with the same name. This can be useful at times,
419 * e.g. to change the range of allowed values or the default value.
421 void
422 g_object_class_install_property (GObjectClass *class,
423 guint property_id,
424 GParamSpec *pspec)
426 g_return_if_fail (G_IS_OBJECT_CLASS (class));
427 g_return_if_fail (G_IS_PARAM_SPEC (pspec));
429 if (CLASS_HAS_DERIVED_CLASS (class))
430 g_error ("Attempt to add property %s::%s to class after it was derived",
431 G_OBJECT_CLASS_NAME (class), pspec->name);
433 class->flags |= CLASS_HAS_PROPS_FLAG;
435 if (pspec->flags & G_PARAM_WRITABLE)
436 g_return_if_fail (class->set_property != NULL);
437 if (pspec->flags & G_PARAM_READABLE)
438 g_return_if_fail (class->get_property != NULL);
439 g_return_if_fail (property_id > 0);
440 g_return_if_fail (PARAM_SPEC_PARAM_ID (pspec) == 0); /* paranoid */
441 if (pspec->flags & G_PARAM_CONSTRUCT)
442 g_return_if_fail ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) == 0);
443 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
444 g_return_if_fail (pspec->flags & G_PARAM_WRITABLE);
446 install_property_internal (G_OBJECT_CLASS_TYPE (class), property_id, pspec);
448 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
449 class->construct_properties = g_slist_prepend (class->construct_properties, pspec);
451 /* for property overrides of construct poperties, we have to get rid
452 * of the overidden inherited construct property
454 pspec = g_param_spec_pool_lookup (pspec_pool, pspec->name, g_type_parent (G_OBJECT_CLASS_TYPE (class)), TRUE);
455 if (pspec && pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
456 class->construct_properties = g_slist_remove (class->construct_properties, pspec);
460 * g_object_interface_install_property:
461 * @g_iface: any interface vtable for the interface, or the default
462 * vtable for the interface.
463 * @pspec: the #GParamSpec for the new property
465 * Add a property to an interface; this is only useful for interfaces
466 * that are added to GObject-derived types. Adding a property to an
467 * interface forces all objects classes with that interface to have a
468 * compatible property. The compatible property could be a newly
469 * created #GParamSpec, but normally
470 * g_object_class_override_property() will be used so that the object
471 * class only needs to provide an implementation and inherits the
472 * property description, default value, bounds, and so forth from the
473 * interface property.
475 * This function is meant to be called from the interface's default
476 * vtable initialization function (the @class_init member of
477 * #GTypeInfo.) It must not be called after after @class_init has
478 * been called for any object types implementing this interface.
480 * Since: 2.4
482 void
483 g_object_interface_install_property (gpointer g_iface,
484 GParamSpec *pspec)
486 GTypeInterface *iface_class = g_iface;
488 g_return_if_fail (G_TYPE_IS_INTERFACE (iface_class->g_type));
489 g_return_if_fail (G_IS_PARAM_SPEC (pspec));
490 g_return_if_fail (!G_IS_PARAM_SPEC_OVERRIDE (pspec)); /* paranoid */
491 g_return_if_fail (PARAM_SPEC_PARAM_ID (pspec) == 0); /* paranoid */
493 install_property_internal (iface_class->g_type, 0, pspec);
497 * g_object_class_find_property:
498 * @oclass: a #GObjectClass
499 * @property_name: the name of the property to look up
501 * Looks up the #GParamSpec for a property of a class.
503 * Returns: the #GParamSpec for the property, or %NULL if the class
504 * doesn't have a property of that name
506 GParamSpec*
507 g_object_class_find_property (GObjectClass *class,
508 const gchar *property_name)
510 GParamSpec *pspec;
511 GParamSpec *redirect;
513 g_return_val_if_fail (G_IS_OBJECT_CLASS (class), NULL);
514 g_return_val_if_fail (property_name != NULL, NULL);
516 pspec = g_param_spec_pool_lookup (pspec_pool,
517 property_name,
518 G_OBJECT_CLASS_TYPE (class),
519 TRUE);
520 if (pspec)
522 redirect = g_param_spec_get_redirect_target (pspec);
523 if (redirect)
524 return redirect;
525 else
526 return pspec;
528 else
529 return NULL;
533 * g_object_interface_find_property:
534 * @g_iface: any interface vtable for the interface, or the default
535 * vtable for the interface
536 * @property_name: name of a property to lookup.
538 * Find the #GParamSpec with the given name for an
539 * interface. Generally, the interface vtable passed in as @g_iface
540 * will be the default vtable from g_type_default_interface_ref(), or,
541 * if you know the interface has already been loaded,
542 * g_type_default_interface_peek().
544 * Since: 2.4
546 * Returns: the #GParamSpec for the property of the interface with the
547 * name @property_name, or %NULL if no such property exists.
549 GParamSpec*
550 g_object_interface_find_property (gpointer g_iface,
551 const gchar *property_name)
553 GTypeInterface *iface_class = g_iface;
555 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface_class->g_type), NULL);
556 g_return_val_if_fail (property_name != NULL, NULL);
558 return g_param_spec_pool_lookup (pspec_pool,
559 property_name,
560 iface_class->g_type,
561 FALSE);
565 * g_object_class_override_property:
566 * @oclass: a #GObjectClass
567 * @property_id: the new property ID
568 * @name: the name of a property registered in a parent class or
569 * in an interface of this class.
571 * Registers @property_id as referring to a property with the
572 * name @name in a parent class or in an interface implemented
573 * by @oclass. This allows this class to <firstterm>override</firstterm>
574 * a property implementation in a parent class or to provide
575 * the implementation of a property from an interface.
577 * <note>
578 * Internally, overriding is implemented by creating a property of type
579 * #GParamSpecOverride; generally operations that query the properties of
580 * the object class, such as g_object_class_find_property() or
581 * g_object_class_list_properties() will return the overridden
582 * property. However, in one case, the @construct_properties argument of
583 * the @constructor virtual function, the #GParamSpecOverride is passed
584 * instead, so that the @param_id field of the #GParamSpec will be
585 * correct. For virtually all uses, this makes no difference. If you
586 * need to get the overridden property, you can call
587 * g_param_spec_get_redirect_target().
588 * </note>
590 * Since: 2.4
592 void
593 g_object_class_override_property (GObjectClass *oclass,
594 guint property_id,
595 const gchar *name)
597 GParamSpec *overridden = NULL;
598 GParamSpec *new;
599 GType parent_type;
601 g_return_if_fail (G_IS_OBJECT_CLASS (oclass));
602 g_return_if_fail (property_id > 0);
603 g_return_if_fail (name != NULL);
605 /* Find the overridden property; first check parent types
607 parent_type = g_type_parent (G_OBJECT_CLASS_TYPE (oclass));
608 if (parent_type != G_TYPE_NONE)
609 overridden = g_param_spec_pool_lookup (pspec_pool,
610 name,
611 parent_type,
612 TRUE);
613 if (!overridden)
615 GType *ifaces;
616 guint n_ifaces;
618 /* Now check interfaces
620 ifaces = g_type_interfaces (G_OBJECT_CLASS_TYPE (oclass), &n_ifaces);
621 while (n_ifaces-- && !overridden)
623 overridden = g_param_spec_pool_lookup (pspec_pool,
624 name,
625 ifaces[n_ifaces],
626 FALSE);
629 g_free (ifaces);
632 if (!overridden)
634 g_warning ("%s: Can't find property to override for '%s::%s'",
635 G_STRFUNC, G_OBJECT_CLASS_NAME (oclass), name);
636 return;
639 new = g_param_spec_override (name, overridden);
640 g_object_class_install_property (oclass, property_id, new);
644 * g_object_class_list_properties:
645 * @oclass: a #GObjectClass
646 * @n_properties: return location for the length of the returned array
648 * Get an array of #GParamSpec* for all properties of a class.
650 * Returns: an array of #GParamSpec* which should be freed after use
652 GParamSpec** /* free result */
653 g_object_class_list_properties (GObjectClass *class,
654 guint *n_properties_p)
656 GParamSpec **pspecs;
657 guint n;
659 g_return_val_if_fail (G_IS_OBJECT_CLASS (class), NULL);
661 pspecs = g_param_spec_pool_list (pspec_pool,
662 G_OBJECT_CLASS_TYPE (class),
663 &n);
664 if (n_properties_p)
665 *n_properties_p = n;
667 return pspecs;
671 * g_object_interface_list_properties:
672 * @g_iface: any interface vtable for the interface, or the default
673 * vtable for the interface
674 * @n_properties_p: location to store number of properties returned.
676 * Lists the properties of an interface.Generally, the interface
677 * vtable passed in as @g_iface will be the default vtable from
678 * g_type_default_interface_ref(), or, if you know the interface has
679 * already been loaded, g_type_default_interface_peek().
681 * Since: 2.4
683 * Returns: a pointer to an array of pointers to #GParamSpec
684 * structures. The paramspecs are owned by GLib, but the
685 * array should be freed with g_free() when you are done with
686 * it.
688 GParamSpec**
689 g_object_interface_list_properties (gpointer g_iface,
690 guint *n_properties_p)
692 GTypeInterface *iface_class = g_iface;
693 GParamSpec **pspecs;
694 guint n;
696 g_return_val_if_fail (G_TYPE_IS_INTERFACE (iface_class->g_type), NULL);
698 pspecs = g_param_spec_pool_list (pspec_pool,
699 iface_class->g_type,
700 &n);
701 if (n_properties_p)
702 *n_properties_p = n;
704 return pspecs;
707 static void
708 g_object_init (GObject *object,
709 GObjectClass *class)
711 object->ref_count = 1;
712 g_datalist_init (&object->qdata);
714 if (CLASS_HAS_PROPS (class))
716 /* freeze object's notification queue, g_object_newv() preserves pairedness */
717 g_object_notify_queue_freeze (object, &property_notify_context);
720 if (CLASS_HAS_CUSTOM_CONSTRUCTOR (class))
722 /* enter construction list for notify_queue_thaw() and to allow construct-only properties */
723 G_LOCK (construction_mutex);
724 construction_objects = g_slist_prepend (construction_objects, object);
725 G_UNLOCK (construction_mutex);
728 #ifdef G_ENABLE_DEBUG
729 IF_DEBUG (OBJECTS)
731 G_LOCK (debug_objects);
732 debug_objects_count++;
733 g_hash_table_insert (debug_objects_ht, object, object);
734 G_UNLOCK (debug_objects);
736 #endif /* G_ENABLE_DEBUG */
739 static void
740 g_object_do_set_property (GObject *object,
741 guint property_id,
742 const GValue *value,
743 GParamSpec *pspec)
745 switch (property_id)
747 default:
748 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
749 break;
753 static void
754 g_object_do_get_property (GObject *object,
755 guint property_id,
756 GValue *value,
757 GParamSpec *pspec)
759 switch (property_id)
761 default:
762 G_OBJECT_WARN_INVALID_PROPERTY_ID (object, property_id, pspec);
763 break;
767 static void
768 g_object_real_dispose (GObject *object)
770 g_signal_handlers_destroy (object);
771 g_datalist_id_set_data (&object->qdata, quark_closure_array, NULL);
772 g_datalist_id_set_data (&object->qdata, quark_weak_refs, NULL);
775 static void
776 g_object_finalize (GObject *object)
778 g_datalist_clear (&object->qdata);
780 #ifdef G_ENABLE_DEBUG
781 IF_DEBUG (OBJECTS)
783 G_LOCK (debug_objects);
784 g_assert (g_hash_table_lookup (debug_objects_ht, object) == object);
785 g_hash_table_remove (debug_objects_ht, object);
786 debug_objects_count--;
787 G_UNLOCK (debug_objects);
789 #endif /* G_ENABLE_DEBUG */
793 static void
794 g_object_dispatch_properties_changed (GObject *object,
795 guint n_pspecs,
796 GParamSpec **pspecs)
798 guint i;
800 for (i = 0; i < n_pspecs; i++)
801 g_signal_emit (object, gobject_signals[NOTIFY], g_quark_from_string (pspecs[i]->name), pspecs[i]);
805 * g_object_run_dispose:
806 * @object: a #GObject
808 * Releases all references to other objects. This can be used to break
809 * reference cycles.
811 * This functions should only be called from object system implementations.
813 void
814 g_object_run_dispose (GObject *object)
816 g_return_if_fail (G_IS_OBJECT (object));
817 g_return_if_fail (object->ref_count > 0);
819 g_object_ref (object);
820 G_OBJECT_GET_CLASS (object)->dispose (object);
821 g_object_unref (object);
825 * g_object_freeze_notify:
826 * @object: a #GObject
828 * Increases the freeze count on @object. If the freeze count is
829 * non-zero, the emission of "notify" signals on @object is
830 * stopped. The signals are queued until the freeze count is decreased
831 * to zero.
833 * This is necessary for accessors that modify multiple properties to prevent
834 * premature notification while the object is still being modified.
836 void
837 g_object_freeze_notify (GObject *object)
839 g_return_if_fail (G_IS_OBJECT (object));
841 if (g_atomic_int_get (&object->ref_count) == 0)
842 return;
844 g_object_ref (object);
845 g_object_notify_queue_freeze (object, &property_notify_context);
846 g_object_unref (object);
850 * g_object_notify:
851 * @object: a #GObject
852 * @property_name: the name of a property installed on the class of @object.
854 * Emits a "notify" signal for the property @property_name on @object.
856 void
857 g_object_notify (GObject *object,
858 const gchar *property_name)
860 GParamSpec *pspec;
862 g_return_if_fail (G_IS_OBJECT (object));
863 g_return_if_fail (property_name != NULL);
864 if (g_atomic_int_get (&object->ref_count) == 0)
865 return;
867 g_object_ref (object);
868 /* We don't need to get the redirect target
869 * (by, e.g. calling g_object_class_find_property())
870 * because g_object_notify_queue_add() does that
872 pspec = g_param_spec_pool_lookup (pspec_pool,
873 property_name,
874 G_OBJECT_TYPE (object),
875 TRUE);
877 if (!pspec)
878 g_warning ("%s: object class `%s' has no property named `%s'",
879 G_STRFUNC,
880 G_OBJECT_TYPE_NAME (object),
881 property_name);
882 else
884 GObjectNotifyQueue *nqueue;
886 nqueue = g_object_notify_queue_freeze (object, &property_notify_context);
887 g_object_notify_queue_add (object, nqueue, pspec);
888 g_object_notify_queue_thaw (object, nqueue);
890 g_object_unref (object);
894 * g_object_thaw_notify:
895 * @object: a #GObject
897 * Reverts the effect of a previous call to
898 * g_object_freeze_notify(). The freeze count is decreased on @object
899 * and when it reaches zero, all queued "notify" signals are emitted.
901 * It is an error to call this function when the freeze count is zero.
903 void
904 g_object_thaw_notify (GObject *object)
906 GObjectNotifyQueue *nqueue;
908 g_return_if_fail (G_IS_OBJECT (object));
909 if (g_atomic_int_get (&object->ref_count) == 0)
910 return;
912 g_object_ref (object);
913 nqueue = g_object_notify_queue_from_object (object, &property_notify_context);
914 if (!nqueue || !nqueue->freeze_count)
915 g_warning ("%s: property-changed notification for %s(%p) is not frozen",
916 G_STRFUNC, G_OBJECT_TYPE_NAME (object), object);
917 else
918 g_object_notify_queue_thaw (object, nqueue);
919 g_object_unref (object);
922 static inline void
923 object_get_property (GObject *object,
924 GParamSpec *pspec,
925 GValue *value)
927 GObjectClass *class = g_type_class_peek (pspec->owner_type);
928 guint param_id = PARAM_SPEC_PARAM_ID (pspec);
929 GParamSpec *redirect;
931 redirect = g_param_spec_get_redirect_target (pspec);
932 if (redirect)
933 pspec = redirect;
935 class->get_property (object, param_id, value, pspec);
938 static inline void
939 object_set_property (GObject *object,
940 GParamSpec *pspec,
941 const GValue *value,
942 GObjectNotifyQueue *nqueue)
944 GValue tmp_value = { 0, };
945 GObjectClass *class = g_type_class_peek (pspec->owner_type);
946 guint param_id = PARAM_SPEC_PARAM_ID (pspec);
947 GParamSpec *redirect;
949 redirect = g_param_spec_get_redirect_target (pspec);
950 if (redirect)
951 pspec = redirect;
953 /* provide a copy to work from, convert (if necessary) and validate */
954 g_value_init (&tmp_value, G_PARAM_SPEC_VALUE_TYPE (pspec));
955 if (!g_value_transform (value, &tmp_value))
956 g_warning ("unable to set property `%s' of type `%s' from value of type `%s'",
957 pspec->name,
958 g_type_name (G_PARAM_SPEC_VALUE_TYPE (pspec)),
959 G_VALUE_TYPE_NAME (value));
960 else if (g_param_value_validate (pspec, &tmp_value) && !(pspec->flags & G_PARAM_LAX_VALIDATION))
962 gchar *contents = g_strdup_value_contents (value);
964 g_warning ("value \"%s\" of type `%s' is invalid or out of range for property `%s' of type `%s'",
965 contents,
966 G_VALUE_TYPE_NAME (value),
967 pspec->name,
968 g_type_name (G_PARAM_SPEC_VALUE_TYPE (pspec)));
969 g_free (contents);
971 else
973 class->set_property (object, param_id, &tmp_value, pspec);
974 g_object_notify_queue_add (object, nqueue, pspec);
976 g_value_unset (&tmp_value);
979 static void
980 object_interface_check_properties (gpointer func_data,
981 gpointer g_iface)
983 GTypeInterface *iface_class = g_iface;
984 GObjectClass *class = g_type_class_peek (iface_class->g_instance_type);
985 GType iface_type = iface_class->g_type;
986 GParamSpec **pspecs;
987 guint n;
989 if (!G_IS_OBJECT_CLASS (class))
990 return;
992 pspecs = g_param_spec_pool_list (pspec_pool, iface_type, &n);
994 while (n--)
996 GParamSpec *class_pspec = g_param_spec_pool_lookup (pspec_pool,
997 pspecs[n]->name,
998 G_OBJECT_CLASS_TYPE (class),
999 TRUE);
1001 if (!class_pspec)
1003 g_critical ("Object class %s doesn't implement property "
1004 "'%s' from interface '%s'",
1005 g_type_name (G_OBJECT_CLASS_TYPE (class)),
1006 pspecs[n]->name,
1007 g_type_name (iface_type));
1009 continue;
1012 /* The implementation paramspec must have a less restrictive
1013 * type than the interface parameter spec for set() and a
1014 * more restrictive type for get(). We just require equality,
1015 * rather than doing something more complicated checking
1016 * the READABLE and WRITABLE flags. We also simplify here
1017 * by only checking the value type, not the G_PARAM_SPEC_TYPE.
1019 if (class_pspec &&
1020 !g_type_is_a (G_PARAM_SPEC_VALUE_TYPE (pspecs[n]),
1021 G_PARAM_SPEC_VALUE_TYPE (class_pspec)))
1023 g_critical ("Property '%s' on class '%s' has type '%s' "
1024 "which is different from the type '%s', "
1025 "of the property on interface '%s'\n",
1026 pspecs[n]->name,
1027 g_type_name (G_OBJECT_CLASS_TYPE (class)),
1028 g_type_name (G_PARAM_SPEC_VALUE_TYPE (class_pspec)),
1029 g_type_name (G_PARAM_SPEC_VALUE_TYPE (pspecs[n])),
1030 g_type_name (iface_type));
1033 #define SUBSET(a,b,mask) (((a) & ~(b) & (mask)) == 0)
1035 /* CONSTRUCT and CONSTRUCT_ONLY add restrictions.
1036 * READABLE and WRITABLE remove restrictions. The implementation
1037 * paramspec must have less restrictive flags.
1039 if (class_pspec &&
1040 (!SUBSET (class_pspec->flags,
1041 pspecs[n]->flags,
1042 G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY) ||
1043 !SUBSET (pspecs[n]->flags,
1044 class_pspec->flags,
1045 G_PARAM_READABLE | G_PARAM_WRITABLE)))
1047 g_critical ("Flags for property '%s' on class '%s' "
1048 "are not compatible with the property on"
1049 "interface '%s'\n",
1050 pspecs[n]->name,
1051 g_type_name (G_OBJECT_CLASS_TYPE (class)),
1052 g_type_name (iface_type));
1054 #undef SUBSET
1057 g_free (pspecs);
1060 GType
1061 g_object_get_type (void)
1063 return G_TYPE_OBJECT;
1067 * g_object_new:
1068 * @object_type: the type id of the #GObject subtype to instantiate
1069 * @first_property_name: the name of the first property
1070 * @...: the value of the first property, followed optionally by more
1071 * name/value pairs, followed by %NULL
1073 * Creates a new instance of a #GObject subtype and sets its properties.
1075 * Construction parameters (see #G_PARAM_CONSTRUCT, #G_PARAM_CONSTRUCT_ONLY)
1076 * which are not explicitly specified are set to their default values.
1078 * Returns: a new instance of @object_type
1080 gpointer
1081 g_object_new (GType object_type,
1082 const gchar *first_property_name,
1083 ...)
1085 GObject *object;
1086 va_list var_args;
1088 g_return_val_if_fail (G_TYPE_IS_OBJECT (object_type), NULL);
1090 va_start (var_args, first_property_name);
1091 object = g_object_new_valist (object_type, first_property_name, var_args);
1092 va_end (var_args);
1094 return object;
1097 static gboolean
1098 slist_maybe_remove (GSList **slist,
1099 gconstpointer data)
1101 GSList *last = NULL, *node = *slist;
1102 while (node)
1104 if (node->data == data)
1106 if (last)
1107 last->next = node->next;
1108 else
1109 *slist = node->next;
1110 g_slist_free_1 (node);
1111 return TRUE;
1113 last = node;
1114 node = last->next;
1116 return FALSE;
1119 static inline gboolean
1120 object_in_construction_list (GObject *object)
1122 gboolean in_construction;
1123 G_LOCK (construction_mutex);
1124 in_construction = g_slist_find (construction_objects, object) != NULL;
1125 G_UNLOCK (construction_mutex);
1126 return in_construction;
1130 * g_object_newv:
1131 * @object_type: the type id of the #GObject subtype to instantiate
1132 * @n_parameters: the length of the @parameters array
1133 * @parameters: an array of #GParameter
1135 * Creates a new instance of a #GObject subtype and sets its properties.
1137 * Construction parameters (see #G_PARAM_CONSTRUCT, #G_PARAM_CONSTRUCT_ONLY)
1138 * which are not explicitly specified are set to their default values.
1140 * Returns: a new instance of @object_type
1142 gpointer
1143 g_object_newv (GType object_type,
1144 guint n_parameters,
1145 GParameter *parameters)
1147 GObjectConstructParam *cparams = NULL, *oparams;
1148 GObjectNotifyQueue *nqueue = NULL; /* shouldn't be initialized, just to silence compiler */
1149 GObject *object;
1150 GObjectClass *class, *unref_class = NULL;
1151 GSList *slist;
1152 guint n_total_cparams = 0, n_cparams = 0, n_oparams = 0, n_cvalues;
1153 GValue *cvalues;
1154 GList *clist = NULL;
1155 gboolean newly_constructed;
1156 guint i;
1158 g_return_val_if_fail (G_TYPE_IS_OBJECT (object_type), NULL);
1160 class = g_type_class_peek_static (object_type);
1161 if (!class)
1162 class = unref_class = g_type_class_ref (object_type);
1163 for (slist = class->construct_properties; slist; slist = slist->next)
1165 clist = g_list_prepend (clist, slist->data);
1166 n_total_cparams += 1;
1169 if (n_parameters == 0 && n_total_cparams == 0)
1171 /* This is a simple object with no construct properties, and
1172 * no properties are being set, so short circuit the parameter
1173 * handling. This speeds up simple object construction.
1175 oparams = NULL;
1176 object = class->constructor (object_type, 0, NULL);
1177 goto did_construction;
1180 /* collect parameters, sort into construction and normal ones */
1181 oparams = g_new (GObjectConstructParam, n_parameters);
1182 cparams = g_new (GObjectConstructParam, n_total_cparams);
1183 for (i = 0; i < n_parameters; i++)
1185 GValue *value = &parameters[i].value;
1186 GParamSpec *pspec = g_param_spec_pool_lookup (pspec_pool,
1187 parameters[i].name,
1188 object_type,
1189 TRUE);
1190 if (!pspec)
1192 g_warning ("%s: object class `%s' has no property named `%s'",
1193 G_STRFUNC,
1194 g_type_name (object_type),
1195 parameters[i].name);
1196 continue;
1198 if (!(pspec->flags & G_PARAM_WRITABLE))
1200 g_warning ("%s: property `%s' of object class `%s' is not writable",
1201 G_STRFUNC,
1202 pspec->name,
1203 g_type_name (object_type));
1204 continue;
1206 if (pspec->flags & (G_PARAM_CONSTRUCT | G_PARAM_CONSTRUCT_ONLY))
1208 GList *list = g_list_find (clist, pspec);
1210 if (!list)
1212 g_warning ("%s: construct property \"%s\" for object `%s' can't be set twice",
1213 G_STRFUNC, pspec->name, g_type_name (object_type));
1214 continue;
1216 cparams[n_cparams].pspec = pspec;
1217 cparams[n_cparams].value = value;
1218 n_cparams++;
1219 if (!list->prev)
1220 clist = list->next;
1221 else
1222 list->prev->next = list->next;
1223 if (list->next)
1224 list->next->prev = list->prev;
1225 g_list_free_1 (list);
1227 else
1229 oparams[n_oparams].pspec = pspec;
1230 oparams[n_oparams].value = value;
1231 n_oparams++;
1235 /* set remaining construction properties to default values */
1236 n_cvalues = n_total_cparams - n_cparams;
1237 cvalues = g_new (GValue, n_cvalues);
1238 while (clist)
1240 GList *tmp = clist->next;
1241 GParamSpec *pspec = clist->data;
1242 GValue *value = cvalues + n_total_cparams - n_cparams - 1;
1244 value->g_type = 0;
1245 g_value_init (value, G_PARAM_SPEC_VALUE_TYPE (pspec));
1246 g_param_value_set_default (pspec, value);
1248 cparams[n_cparams].pspec = pspec;
1249 cparams[n_cparams].value = value;
1250 n_cparams++;
1252 g_list_free_1 (clist);
1253 clist = tmp;
1256 /* construct object from construction parameters */
1257 object = class->constructor (object_type, n_total_cparams, cparams);
1258 /* free construction values */
1259 g_free (cparams);
1260 while (n_cvalues--)
1261 g_value_unset (cvalues + n_cvalues);
1262 g_free (cvalues);
1264 did_construction:
1265 if (CLASS_HAS_CUSTOM_CONSTRUCTOR (class))
1267 /* adjust freeze_count according to g_object_init() and remaining properties */
1268 G_LOCK (construction_mutex);
1269 newly_constructed = slist_maybe_remove (&construction_objects, object);
1270 G_UNLOCK (construction_mutex);
1272 else
1273 newly_constructed = TRUE;
1275 if (CLASS_HAS_PROPS (class))
1277 if (newly_constructed || n_oparams)
1278 nqueue = g_object_notify_queue_freeze (object, &property_notify_context);
1279 if (newly_constructed)
1280 g_object_notify_queue_thaw (object, nqueue);
1283 /* run 'constructed' handler if there is one */
1284 if (newly_constructed && class->constructed)
1285 class->constructed (object);
1287 /* set remaining properties */
1288 for (i = 0; i < n_oparams; i++)
1289 object_set_property (object, oparams[i].pspec, oparams[i].value, nqueue);
1290 g_free (oparams);
1292 if (CLASS_HAS_PROPS (class))
1294 /* release our own freeze count and handle notifications */
1295 if (newly_constructed || n_oparams)
1296 g_object_notify_queue_thaw (object, nqueue);
1299 if (unref_class)
1300 g_type_class_unref (unref_class);
1302 return object;
1306 * g_object_new_valist:
1307 * @object_type: the type id of the #GObject subtype to instantiate
1308 * @first_property_name: the name of the first property
1309 * @var_args: the value of the first property, followed optionally by more
1310 * name/value pairs, followed by %NULL
1312 * Creates a new instance of a #GObject subtype and sets its properties.
1314 * Construction parameters (see #G_PARAM_CONSTRUCT, #G_PARAM_CONSTRUCT_ONLY)
1315 * which are not explicitly specified are set to their default values.
1317 * Returns: a new instance of @object_type
1319 GObject*
1320 g_object_new_valist (GType object_type,
1321 const gchar *first_property_name,
1322 va_list var_args)
1324 GObjectClass *class;
1325 GParameter *params;
1326 const gchar *name;
1327 GObject *object;
1328 guint n_params = 0, n_alloced_params = 16;
1330 g_return_val_if_fail (G_TYPE_IS_OBJECT (object_type), NULL);
1332 if (!first_property_name)
1333 return g_object_newv (object_type, 0, NULL);
1335 class = g_type_class_ref (object_type);
1337 params = g_new (GParameter, n_alloced_params);
1338 name = first_property_name;
1339 while (name)
1341 gchar *error = NULL;
1342 GParamSpec *pspec = g_param_spec_pool_lookup (pspec_pool,
1343 name,
1344 object_type,
1345 TRUE);
1346 if (!pspec)
1348 g_warning ("%s: object class `%s' has no property named `%s'",
1349 G_STRFUNC,
1350 g_type_name (object_type),
1351 name);
1352 break;
1354 if (n_params >= n_alloced_params)
1356 n_alloced_params += 16;
1357 params = g_renew (GParameter, params, n_alloced_params);
1359 params[n_params].name = name;
1360 params[n_params].value.g_type = 0;
1361 g_value_init (&params[n_params].value, G_PARAM_SPEC_VALUE_TYPE (pspec));
1362 G_VALUE_COLLECT (&params[n_params].value, var_args, 0, &error);
1363 if (error)
1365 g_warning ("%s: %s", G_STRFUNC, error);
1366 g_free (error);
1367 g_value_unset (&params[n_params].value);
1368 break;
1370 n_params++;
1371 name = va_arg (var_args, gchar*);
1374 object = g_object_newv (object_type, n_params, params);
1376 while (n_params--)
1377 g_value_unset (&params[n_params].value);
1378 g_free (params);
1380 g_type_class_unref (class);
1382 return object;
1385 static GObject*
1386 g_object_constructor (GType type,
1387 guint n_construct_properties,
1388 GObjectConstructParam *construct_params)
1390 GObject *object;
1392 /* create object */
1393 object = (GObject*) g_type_create_instance (type);
1395 /* set construction parameters */
1396 if (n_construct_properties)
1398 GObjectNotifyQueue *nqueue = g_object_notify_queue_freeze (object, &property_notify_context);
1400 /* set construct properties */
1401 while (n_construct_properties--)
1403 GValue *value = construct_params->value;
1404 GParamSpec *pspec = construct_params->pspec;
1406 construct_params++;
1407 object_set_property (object, pspec, value, nqueue);
1409 g_object_notify_queue_thaw (object, nqueue);
1410 /* the notification queue is still frozen from g_object_init(), so
1411 * we don't need to handle it here, g_object_newv() takes
1412 * care of that
1416 return object;
1420 * g_object_set_valist:
1421 * @object: a #GObject
1422 * @first_property_name: name of the first property to set
1423 * @var_args: value for the first property, followed optionally by more
1424 * name/value pairs, followed by %NULL
1426 * Sets properties on an object.
1428 void
1429 g_object_set_valist (GObject *object,
1430 const gchar *first_property_name,
1431 va_list var_args)
1433 GObjectNotifyQueue *nqueue;
1434 const gchar *name;
1436 g_return_if_fail (G_IS_OBJECT (object));
1438 g_object_ref (object);
1439 nqueue = g_object_notify_queue_freeze (object, &property_notify_context);
1441 name = first_property_name;
1442 while (name)
1444 GValue value = { 0, };
1445 GParamSpec *pspec;
1446 gchar *error = NULL;
1448 pspec = g_param_spec_pool_lookup (pspec_pool,
1449 name,
1450 G_OBJECT_TYPE (object),
1451 TRUE);
1452 if (!pspec)
1454 g_warning ("%s: object class `%s' has no property named `%s'",
1455 G_STRFUNC,
1456 G_OBJECT_TYPE_NAME (object),
1457 name);
1458 break;
1460 if (!(pspec->flags & G_PARAM_WRITABLE))
1462 g_warning ("%s: property `%s' of object class `%s' is not writable",
1463 G_STRFUNC,
1464 pspec->name,
1465 G_OBJECT_TYPE_NAME (object));
1466 break;
1468 if ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) && !object_in_construction_list (object))
1470 g_warning ("%s: construct property \"%s\" for object `%s' can't be set after construction",
1471 G_STRFUNC, pspec->name, G_OBJECT_TYPE_NAME (object));
1472 break;
1475 g_value_init (&value, G_PARAM_SPEC_VALUE_TYPE (pspec));
1477 G_VALUE_COLLECT (&value, var_args, 0, &error);
1478 if (error)
1480 g_warning ("%s: %s", G_STRFUNC, error);
1481 g_free (error);
1482 g_value_unset (&value);
1483 break;
1486 object_set_property (object, pspec, &value, nqueue);
1487 g_value_unset (&value);
1489 name = va_arg (var_args, gchar*);
1492 g_object_notify_queue_thaw (object, nqueue);
1493 g_object_unref (object);
1497 * g_object_get_valist:
1498 * @object: a #GObject
1499 * @first_property_name: name of the first property to get
1500 * @var_args: return location for the first property, followed optionally by more
1501 * name/return location pairs, followed by %NULL
1503 * Gets properties of an object.
1505 * In general, a copy is made of the property contents and the caller
1506 * is responsible for freeing the memory in the appropriate manner for
1507 * the type, for instance by calling g_free() or g_object_unref().
1509 * See g_object_get().
1511 void
1512 g_object_get_valist (GObject *object,
1513 const gchar *first_property_name,
1514 va_list var_args)
1516 const gchar *name;
1518 g_return_if_fail (G_IS_OBJECT (object));
1520 g_object_ref (object);
1522 name = first_property_name;
1524 while (name)
1526 GValue value = { 0, };
1527 GParamSpec *pspec;
1528 gchar *error;
1530 pspec = g_param_spec_pool_lookup (pspec_pool,
1531 name,
1532 G_OBJECT_TYPE (object),
1533 TRUE);
1534 if (!pspec)
1536 g_warning ("%s: object class `%s' has no property named `%s'",
1537 G_STRFUNC,
1538 G_OBJECT_TYPE_NAME (object),
1539 name);
1540 break;
1542 if (!(pspec->flags & G_PARAM_READABLE))
1544 g_warning ("%s: property `%s' of object class `%s' is not readable",
1545 G_STRFUNC,
1546 pspec->name,
1547 G_OBJECT_TYPE_NAME (object));
1548 break;
1551 g_value_init (&value, G_PARAM_SPEC_VALUE_TYPE (pspec));
1553 object_get_property (object, pspec, &value);
1555 G_VALUE_LCOPY (&value, var_args, 0, &error);
1556 if (error)
1558 g_warning ("%s: %s", G_STRFUNC, error);
1559 g_free (error);
1560 g_value_unset (&value);
1561 break;
1564 g_value_unset (&value);
1566 name = va_arg (var_args, gchar*);
1569 g_object_unref (object);
1573 * g_object_set:
1574 * @object: a #GObject
1575 * @first_property_name: name of the first property to set
1576 * @...: value for the first property, followed optionally by more
1577 * name/value pairs, followed by %NULL
1579 * Sets properties on an object.
1581 void
1582 g_object_set (gpointer _object,
1583 const gchar *first_property_name,
1584 ...)
1586 GObject *object = _object;
1587 va_list var_args;
1589 g_return_if_fail (G_IS_OBJECT (object));
1591 va_start (var_args, first_property_name);
1592 g_object_set_valist (object, first_property_name, var_args);
1593 va_end (var_args);
1597 * g_object_get:
1598 * @object: a #GObject
1599 * @first_property_name: name of the first property to get
1600 * @...: return location for the first property, followed optionally by more
1601 * name/return location pairs, followed by %NULL
1603 * Gets properties of an object.
1605 * In general, a copy is made of the property contents and the caller
1606 * is responsible for freeing the memory in the appropriate manner for
1607 * the type, for instance by calling g_free() or g_object_unref().
1609 * <example>
1610 * <title>Using g_object_get(<!-- -->)</title>
1611 * An example of using g_object_get() to get the contents
1612 * of three properties - one of type #G_TYPE_INT,
1613 * one of type #G_TYPE_STRING, and one of type #G_TYPE_OBJECT:
1614 * <programlisting>
1615 * gint intval;
1616 * gchar *strval;
1617 * GObject *objval;
1619 * g_object_get (my_object,
1620 * "int-property", &intval,
1621 * "str-property", &strval,
1622 * "obj-property", &objval,
1623 * NULL);
1625 * // Do something with intval, strval, objval
1627 * g_free (strval);
1628 * g_object_unref (objval);
1629 * </programlisting>
1630 * </example>
1632 void
1633 g_object_get (gpointer _object,
1634 const gchar *first_property_name,
1635 ...)
1637 GObject *object = _object;
1638 va_list var_args;
1640 g_return_if_fail (G_IS_OBJECT (object));
1642 va_start (var_args, first_property_name);
1643 g_object_get_valist (object, first_property_name, var_args);
1644 va_end (var_args);
1648 * g_object_set_property:
1649 * @object: a #GObject
1650 * @property_name: the name of the property to set
1651 * @value: the value
1653 * Sets a property on an object.
1655 void
1656 g_object_set_property (GObject *object,
1657 const gchar *property_name,
1658 const GValue *value)
1660 GObjectNotifyQueue *nqueue;
1661 GParamSpec *pspec;
1663 g_return_if_fail (G_IS_OBJECT (object));
1664 g_return_if_fail (property_name != NULL);
1665 g_return_if_fail (G_IS_VALUE (value));
1667 g_object_ref (object);
1668 nqueue = g_object_notify_queue_freeze (object, &property_notify_context);
1670 pspec = g_param_spec_pool_lookup (pspec_pool,
1671 property_name,
1672 G_OBJECT_TYPE (object),
1673 TRUE);
1674 if (!pspec)
1675 g_warning ("%s: object class `%s' has no property named `%s'",
1676 G_STRFUNC,
1677 G_OBJECT_TYPE_NAME (object),
1678 property_name);
1679 else if (!(pspec->flags & G_PARAM_WRITABLE))
1680 g_warning ("%s: property `%s' of object class `%s' is not writable",
1681 G_STRFUNC,
1682 pspec->name,
1683 G_OBJECT_TYPE_NAME (object));
1684 else if ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) && !object_in_construction_list (object))
1685 g_warning ("%s: construct property \"%s\" for object `%s' can't be set after construction",
1686 G_STRFUNC, pspec->name, G_OBJECT_TYPE_NAME (object));
1687 else
1688 object_set_property (object, pspec, value, nqueue);
1690 g_object_notify_queue_thaw (object, nqueue);
1691 g_object_unref (object);
1695 * g_object_get_property:
1696 * @object: a #GObject
1697 * @property_name: the name of the property to get
1698 * @value: return location for the property value
1700 * Gets a property of an object.
1702 * In general, a copy is made of the property contents and the caller is
1703 * responsible for freeing the memory by calling g_value_unset().
1705 * Note that g_object_get_property() is really intended for language
1706 * bindings, g_object_get() is much more convenient for C programming.
1708 void
1709 g_object_get_property (GObject *object,
1710 const gchar *property_name,
1711 GValue *value)
1713 GParamSpec *pspec;
1715 g_return_if_fail (G_IS_OBJECT (object));
1716 g_return_if_fail (property_name != NULL);
1717 g_return_if_fail (G_IS_VALUE (value));
1719 g_object_ref (object);
1721 pspec = g_param_spec_pool_lookup (pspec_pool,
1722 property_name,
1723 G_OBJECT_TYPE (object),
1724 TRUE);
1725 if (!pspec)
1726 g_warning ("%s: object class `%s' has no property named `%s'",
1727 G_STRFUNC,
1728 G_OBJECT_TYPE_NAME (object),
1729 property_name);
1730 else if (!(pspec->flags & G_PARAM_READABLE))
1731 g_warning ("%s: property `%s' of object class `%s' is not readable",
1732 G_STRFUNC,
1733 pspec->name,
1734 G_OBJECT_TYPE_NAME (object));
1735 else
1737 GValue *prop_value, tmp_value = { 0, };
1739 /* auto-conversion of the callers value type
1741 if (G_VALUE_TYPE (value) == G_PARAM_SPEC_VALUE_TYPE (pspec))
1743 g_value_reset (value);
1744 prop_value = value;
1746 else if (!g_value_type_transformable (G_PARAM_SPEC_VALUE_TYPE (pspec), G_VALUE_TYPE (value)))
1748 g_warning ("%s: can't retrieve property `%s' of type `%s' as value of type `%s'",
1749 G_STRFUNC, pspec->name,
1750 g_type_name (G_PARAM_SPEC_VALUE_TYPE (pspec)),
1751 G_VALUE_TYPE_NAME (value));
1752 g_object_unref (object);
1753 return;
1755 else
1757 g_value_init (&tmp_value, G_PARAM_SPEC_VALUE_TYPE (pspec));
1758 prop_value = &tmp_value;
1760 object_get_property (object, pspec, prop_value);
1761 if (prop_value != value)
1763 g_value_transform (prop_value, value);
1764 g_value_unset (&tmp_value);
1768 g_object_unref (object);
1772 * g_object_connect:
1773 * @object: a #GObject
1774 * @signal_spec: the spec for the first signal
1775 * @...: #GCallback for the first signal, followed by data for the
1776 * first signal, followed optionally by more signal
1777 * spec/callback/data triples, followed by %NULL
1779 * A convenience function to connect multiple signals at once.
1781 * The signal specs expected by this function have the form
1782 * "modifier::signal_name", where modifier can be one of the following:
1783 * <variablelist>
1784 * <varlistentry>
1785 * <term>signal</term>
1786 * <listitem><para>
1787 * equivalent to <literal>g_signal_connect_data (..., NULL, 0)</literal>
1788 * </para></listitem>
1789 * </varlistentry>
1790 * <varlistentry>
1791 * <term>object_signal</term>
1792 * <term>object-signal</term>
1793 * <listitem><para>
1794 * equivalent to <literal>g_signal_connect_object (..., 0)</literal>
1795 * </para></listitem>
1796 * </varlistentry>
1797 * <varlistentry>
1798 * <term>swapped_signal</term>
1799 * <term>swapped-signal</term>
1800 * <listitem><para>
1801 * equivalent to <literal>g_signal_connect_data (..., NULL, G_CONNECT_SWAPPED)</literal>
1802 * </para></listitem>
1803 * </varlistentry>
1804 * <varlistentry>
1805 * <term>swapped_object_signal</term>
1806 * <term>swapped-object-signal</term>
1807 * <listitem><para>
1808 * equivalent to <literal>g_signal_connect_object (..., G_CONNECT_SWAPPED)</literal>
1809 * </para></listitem>
1810 * </varlistentry>
1811 * <varlistentry>
1812 * <term>signal_after</term>
1813 * <term>signal-after</term>
1814 * <listitem><para>
1815 * equivalent to <literal>g_signal_connect_data (..., NULL, G_CONNECT_AFTER)</literal>
1816 * </para></listitem>
1817 * </varlistentry>
1818 * <varlistentry>
1819 * <term>object_signal_after</term>
1820 * <term>object-signal-after</term>
1821 * <listitem><para>
1822 * equivalent to <literal>g_signal_connect_object (..., G_CONNECT_AFTER)</literal>
1823 * </para></listitem>
1824 * </varlistentry>
1825 * <varlistentry>
1826 * <term>swapped_signal_after</term>
1827 * <term>swapped-signal-after</term>
1828 * <listitem><para>
1829 * equivalent to <literal>g_signal_connect_data (..., NULL, G_CONNECT_SWAPPED | G_CONNECT_AFTER)</literal>
1830 * </para></listitem>
1831 * </varlistentry>
1832 * <varlistentry>
1833 * <term>swapped_object_signal_after</term>
1834 * <term>swapped-object-signal-after</term>
1835 * <listitem><para>
1836 * equivalent to <literal>g_signal_connect_object (..., G_CONNECT_SWAPPED | G_CONNECT_AFTER)</literal>
1837 * </para></listitem>
1838 * </varlistentry>
1839 * </variablelist>
1841 * |[
1842 * menu->toplevel = g_object_connect (g_object_new (GTK_TYPE_WINDOW,
1843 * "type", GTK_WINDOW_POPUP,
1844 * "child", menu,
1845 * NULL),
1846 * "signal::event", gtk_menu_window_event, menu,
1847 * "signal::size_request", gtk_menu_window_size_request, menu,
1848 * "signal::destroy", gtk_widget_destroyed, &amp;menu-&gt;toplevel,
1849 * NULL);
1850 * ]|
1852 * Returns: @object
1854 gpointer
1855 g_object_connect (gpointer _object,
1856 const gchar *signal_spec,
1857 ...)
1859 GObject *object = _object;
1860 va_list var_args;
1862 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
1863 g_return_val_if_fail (object->ref_count > 0, object);
1865 va_start (var_args, signal_spec);
1866 while (signal_spec)
1868 GCallback callback = va_arg (var_args, GCallback);
1869 gpointer data = va_arg (var_args, gpointer);
1870 gulong sid;
1872 if (strncmp (signal_spec, "signal::", 8) == 0)
1873 sid = g_signal_connect_data (object, signal_spec + 8,
1874 callback, data, NULL,
1876 else if (strncmp (signal_spec, "object_signal::", 15) == 0 ||
1877 strncmp (signal_spec, "object-signal::", 15) == 0)
1878 sid = g_signal_connect_object (object, signal_spec + 15,
1879 callback, data,
1881 else if (strncmp (signal_spec, "swapped_signal::", 16) == 0 ||
1882 strncmp (signal_spec, "swapped-signal::", 16) == 0)
1883 sid = g_signal_connect_data (object, signal_spec + 16,
1884 callback, data, NULL,
1885 G_CONNECT_SWAPPED);
1886 else if (strncmp (signal_spec, "swapped_object_signal::", 23) == 0 ||
1887 strncmp (signal_spec, "swapped-object-signal::", 23) == 0)
1888 sid = g_signal_connect_object (object, signal_spec + 23,
1889 callback, data,
1890 G_CONNECT_SWAPPED);
1891 else if (strncmp (signal_spec, "signal_after::", 14) == 0 ||
1892 strncmp (signal_spec, "signal-after::", 14) == 0)
1893 sid = g_signal_connect_data (object, signal_spec + 14,
1894 callback, data, NULL,
1895 G_CONNECT_AFTER);
1896 else if (strncmp (signal_spec, "object_signal_after::", 21) == 0 ||
1897 strncmp (signal_spec, "object-signal-after::", 21) == 0)
1898 sid = g_signal_connect_object (object, signal_spec + 21,
1899 callback, data,
1900 G_CONNECT_AFTER);
1901 else if (strncmp (signal_spec, "swapped_signal_after::", 22) == 0 ||
1902 strncmp (signal_spec, "swapped-signal-after::", 22) == 0)
1903 sid = g_signal_connect_data (object, signal_spec + 22,
1904 callback, data, NULL,
1905 G_CONNECT_SWAPPED | G_CONNECT_AFTER);
1906 else if (strncmp (signal_spec, "swapped_object_signal_after::", 29) == 0 ||
1907 strncmp (signal_spec, "swapped-object-signal-after::", 29) == 0)
1908 sid = g_signal_connect_object (object, signal_spec + 29,
1909 callback, data,
1910 G_CONNECT_SWAPPED | G_CONNECT_AFTER);
1911 else
1913 g_warning ("%s: invalid signal spec \"%s\"", G_STRFUNC, signal_spec);
1914 break;
1916 signal_spec = va_arg (var_args, gchar*);
1918 va_end (var_args);
1920 return object;
1924 * g_object_disconnect:
1925 * @object: a #GObject
1926 * @signal_spec: the spec for the first signal
1927 * @...: #GCallback for the first signal, followed by data for the first signal,
1928 * followed optionally by more signal spec/callback/data triples,
1929 * followed by %NULL
1931 * A convenience function to disconnect multiple signals at once.
1933 * The signal specs expected by this function have the form
1934 * "any_signal", which means to disconnect any signal with matching
1935 * callback and data, or "any_signal::signal_name", which only
1936 * disconnects the signal named "signal_name".
1938 void
1939 g_object_disconnect (gpointer _object,
1940 const gchar *signal_spec,
1941 ...)
1943 GObject *object = _object;
1944 va_list var_args;
1946 g_return_if_fail (G_IS_OBJECT (object));
1947 g_return_if_fail (object->ref_count > 0);
1949 va_start (var_args, signal_spec);
1950 while (signal_spec)
1952 GCallback callback = va_arg (var_args, GCallback);
1953 gpointer data = va_arg (var_args, gpointer);
1954 guint sid = 0, detail = 0, mask = 0;
1956 if (strncmp (signal_spec, "any_signal::", 12) == 0 ||
1957 strncmp (signal_spec, "any-signal::", 12) == 0)
1959 signal_spec += 12;
1960 mask = G_SIGNAL_MATCH_ID | G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA;
1962 else if (strcmp (signal_spec, "any_signal") == 0 ||
1963 strcmp (signal_spec, "any-signal") == 0)
1965 signal_spec += 10;
1966 mask = G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA;
1968 else
1970 g_warning ("%s: invalid signal spec \"%s\"", G_STRFUNC, signal_spec);
1971 break;
1974 if ((mask & G_SIGNAL_MATCH_ID) &&
1975 !g_signal_parse_name (signal_spec, G_OBJECT_TYPE (object), &sid, &detail, FALSE))
1976 g_warning ("%s: invalid signal name \"%s\"", G_STRFUNC, signal_spec);
1977 else if (!g_signal_handlers_disconnect_matched (object, mask | (detail ? G_SIGNAL_MATCH_DETAIL : 0),
1978 sid, detail,
1979 NULL, (gpointer)callback, data))
1980 g_warning ("%s: signal handler %p(%p) is not connected", G_STRFUNC, callback, data);
1981 signal_spec = va_arg (var_args, gchar*);
1983 va_end (var_args);
1986 typedef struct {
1987 GObject *object;
1988 guint n_weak_refs;
1989 struct {
1990 GWeakNotify notify;
1991 gpointer data;
1992 } weak_refs[1]; /* flexible array */
1993 } WeakRefStack;
1995 static void
1996 weak_refs_notify (gpointer data)
1998 WeakRefStack *wstack = data;
1999 guint i;
2001 for (i = 0; i < wstack->n_weak_refs; i++)
2002 wstack->weak_refs[i].notify (wstack->weak_refs[i].data, wstack->object);
2003 g_free (wstack);
2007 * g_object_weak_ref:
2008 * @object: #GObject to reference weakly
2009 * @notify: callback to invoke before the object is freed
2010 * @data: extra data to pass to notify
2012 * Adds a weak reference callback to an object. Weak references are
2013 * used for notification when an object is finalized. They are called
2014 * "weak references" because they allow you to safely hold a pointer
2015 * to an object without calling g_object_ref() (g_object_ref() adds a
2016 * strong reference, that is, forces the object to stay alive).
2018 void
2019 g_object_weak_ref (GObject *object,
2020 GWeakNotify notify,
2021 gpointer data)
2023 WeakRefStack *wstack;
2024 guint i;
2026 g_return_if_fail (G_IS_OBJECT (object));
2027 g_return_if_fail (notify != NULL);
2028 g_return_if_fail (object->ref_count >= 1);
2030 wstack = g_datalist_id_remove_no_notify (&object->qdata, quark_weak_refs);
2031 if (wstack)
2033 i = wstack->n_weak_refs++;
2034 wstack = g_realloc (wstack, sizeof (*wstack) + sizeof (wstack->weak_refs[0]) * i);
2036 else
2038 wstack = g_renew (WeakRefStack, NULL, 1);
2039 wstack->object = object;
2040 wstack->n_weak_refs = 1;
2041 i = 0;
2043 wstack->weak_refs[i].notify = notify;
2044 wstack->weak_refs[i].data = data;
2045 g_datalist_id_set_data_full (&object->qdata, quark_weak_refs, wstack, weak_refs_notify);
2049 * g_object_weak_unref:
2050 * @object: #GObject to remove a weak reference from
2051 * @notify: callback to search for
2052 * @data: data to search for
2054 * Removes a weak reference callback to an object.
2056 void
2057 g_object_weak_unref (GObject *object,
2058 GWeakNotify notify,
2059 gpointer data)
2061 WeakRefStack *wstack;
2062 gboolean found_one = FALSE;
2064 g_return_if_fail (G_IS_OBJECT (object));
2065 g_return_if_fail (notify != NULL);
2067 wstack = g_datalist_id_get_data (&object->qdata, quark_weak_refs);
2068 if (wstack)
2070 guint i;
2072 for (i = 0; i < wstack->n_weak_refs; i++)
2073 if (wstack->weak_refs[i].notify == notify &&
2074 wstack->weak_refs[i].data == data)
2076 found_one = TRUE;
2077 wstack->n_weak_refs -= 1;
2078 if (i != wstack->n_weak_refs)
2079 wstack->weak_refs[i] = wstack->weak_refs[wstack->n_weak_refs];
2081 break;
2084 if (!found_one)
2085 g_warning ("%s: couldn't find weak ref %p(%p)", G_STRFUNC, notify, data);
2089 * g_object_add_weak_pointer:
2090 * @object: The object that should be weak referenced.
2091 * @weak_pointer_location: The memory address of a pointer.
2093 * Adds a weak reference from weak_pointer to @object to indicate that
2094 * the pointer located at @weak_pointer_location is only valid during
2095 * the lifetime of @object. When the @object is finalized,
2096 * @weak_pointer will be set to %NULL.
2098 void
2099 g_object_add_weak_pointer (GObject *object,
2100 gpointer *weak_pointer_location)
2102 g_return_if_fail (G_IS_OBJECT (object));
2103 g_return_if_fail (weak_pointer_location != NULL);
2105 g_object_weak_ref (object,
2106 (GWeakNotify) g_nullify_pointer,
2107 weak_pointer_location);
2111 * g_object_remove_weak_pointer:
2112 * @object: The object that is weak referenced.
2113 * @weak_pointer_location: The memory address of a pointer.
2115 * Removes a weak reference from @object that was previously added
2116 * using g_object_add_weak_pointer(). The @weak_pointer_location has
2117 * to match the one used with g_object_add_weak_pointer().
2119 void
2120 g_object_remove_weak_pointer (GObject *object,
2121 gpointer *weak_pointer_location)
2123 g_return_if_fail (G_IS_OBJECT (object));
2124 g_return_if_fail (weak_pointer_location != NULL);
2126 g_object_weak_unref (object,
2127 (GWeakNotify) g_nullify_pointer,
2128 weak_pointer_location);
2131 static guint
2132 object_floating_flag_handler (GObject *object,
2133 gint job)
2135 switch (job)
2137 gpointer oldvalue;
2138 case +1: /* force floating if possible */
2140 oldvalue = g_atomic_pointer_get (&object->qdata);
2141 while (!g_atomic_pointer_compare_and_exchange ((void**) &object->qdata, oldvalue,
2142 (gpointer) ((gsize) oldvalue | OBJECT_FLOATING_FLAG)));
2143 return (gsize) oldvalue & OBJECT_FLOATING_FLAG;
2144 case -1: /* sink if possible */
2146 oldvalue = g_atomic_pointer_get (&object->qdata);
2147 while (!g_atomic_pointer_compare_and_exchange ((void**) &object->qdata, oldvalue,
2148 (gpointer) ((gsize) oldvalue & ~(gsize) OBJECT_FLOATING_FLAG)));
2149 return (gsize) oldvalue & OBJECT_FLOATING_FLAG;
2150 default: /* check floating */
2151 return 0 != ((gsize) g_atomic_pointer_get (&object->qdata) & OBJECT_FLOATING_FLAG);
2156 * g_object_is_floating:
2157 * @object: a #GObject
2159 * Checks wether @object has a <link linkend="floating-ref">floating</link>
2160 * reference.
2162 * Since: 2.10
2164 * Returns: %TRUE if @object has a floating reference
2166 gboolean
2167 g_object_is_floating (gpointer _object)
2169 GObject *object = _object;
2170 g_return_val_if_fail (G_IS_OBJECT (object), FALSE);
2171 return floating_flag_handler (object, 0);
2175 * g_object_ref_sink:
2176 * @object: a #GObject
2178 * Increase the reference count of @object, and possibly remove the
2179 * <link linkend="floating-ref">floating</link> reference, if @object
2180 * has a floating reference.
2182 * In other words, if the object is floating, then this call "assumes
2183 * ownership" of the floating reference, converting it to a normal
2184 * reference by clearing the floating flag while leaving the reference
2185 * count unchanged. If the object is not floating, then this call
2186 * adds a new normal reference increasing the reference count by one.
2188 * Since: 2.10
2190 * Returns: @object
2192 gpointer
2193 g_object_ref_sink (gpointer _object)
2195 GObject *object = _object;
2196 gboolean was_floating;
2197 g_return_val_if_fail (G_IS_OBJECT (object), object);
2198 g_return_val_if_fail (object->ref_count >= 1, object);
2199 g_object_ref (object);
2200 was_floating = floating_flag_handler (object, -1);
2201 if (was_floating)
2202 g_object_unref (object);
2203 return object;
2207 * g_object_force_floating:
2208 * @object: a #GObject
2210 * This function is intended for #GObject implementations to re-enforce a
2211 * <link linkend="floating-ref">floating</link> object reference.
2212 * Doing this is seldomly required, all
2213 * #GInitiallyUnowned<!-- -->s are created with a floating reference which
2214 * usually just needs to be sunken by calling g_object_ref_sink().
2216 * Since: 2.10
2218 void
2219 g_object_force_floating (GObject *object)
2221 gboolean was_floating;
2222 g_return_if_fail (G_IS_OBJECT (object));
2223 g_return_if_fail (object->ref_count >= 1);
2225 was_floating = floating_flag_handler (object, +1);
2228 typedef struct {
2229 GObject *object;
2230 guint n_toggle_refs;
2231 struct {
2232 GToggleNotify notify;
2233 gpointer data;
2234 } toggle_refs[1]; /* flexible array */
2235 } ToggleRefStack;
2237 static void
2238 toggle_refs_notify (GObject *object,
2239 gboolean is_last_ref)
2241 ToggleRefStack *tstack = g_datalist_id_get_data (&object->qdata, quark_toggle_refs);
2243 /* Reentrancy here is not as tricky as it seems, because a toggle reference
2244 * will only be notified when there is exactly one of them.
2246 g_assert (tstack->n_toggle_refs == 1);
2247 tstack->toggle_refs[0].notify (tstack->toggle_refs[0].data, tstack->object, is_last_ref);
2251 * g_object_add_toggle_ref:
2252 * @object: a #GObject
2253 * @notify: a function to call when this reference is the
2254 * last reference to the object, or is no longer
2255 * the last reference.
2256 * @data: data to pass to @notify
2258 * Increases the reference count of the object by one and sets a
2259 * callback to be called when all other references to the object are
2260 * dropped, or when this is already the last reference to the object
2261 * and another reference is established.
2263 * This functionality is intended for binding @object to a proxy
2264 * object managed by another memory manager. This is done with two
2265 * paired references: the strong reference added by
2266 * g_object_add_toggle_ref() and a reverse reference to the proxy
2267 * object which is either a strong reference or weak reference.
2269 * The setup is that when there are no other references to @object,
2270 * only a weak reference is held in the reverse direction from @object
2271 * to the proxy object, but when there are other references held to
2272 * @object, a strong reference is held. The @notify callback is called
2273 * when the reference from @object to the proxy object should be
2274 * <firstterm>toggled</firstterm> from strong to weak (@is_last_ref
2275 * true) or weak to strong (@is_last_ref false).
2277 * Since a (normal) reference must be held to the object before
2278 * calling g_object_toggle_ref(), the initial state of the reverse
2279 * link is always strong.
2281 * Multiple toggle references may be added to the same gobject,
2282 * however if there are multiple toggle references to an object, none
2283 * of them will ever be notified until all but one are removed. For
2284 * this reason, you should only ever use a toggle reference if there
2285 * is important state in the proxy object.
2287 * Since: 2.8
2289 void
2290 g_object_add_toggle_ref (GObject *object,
2291 GToggleNotify notify,
2292 gpointer data)
2294 ToggleRefStack *tstack;
2295 guint i;
2297 g_return_if_fail (G_IS_OBJECT (object));
2298 g_return_if_fail (notify != NULL);
2299 g_return_if_fail (object->ref_count >= 1);
2301 g_object_ref (object);
2303 tstack = g_datalist_id_remove_no_notify (&object->qdata, quark_toggle_refs);
2304 if (tstack)
2306 i = tstack->n_toggle_refs++;
2307 /* allocate i = tstate->n_toggle_refs - 1 positions beyond the 1 declared
2308 * in tstate->toggle_refs */
2309 tstack = g_realloc (tstack, sizeof (*tstack) + sizeof (tstack->toggle_refs[0]) * i);
2311 else
2313 tstack = g_renew (ToggleRefStack, NULL, 1);
2314 tstack->object = object;
2315 tstack->n_toggle_refs = 1;
2316 i = 0;
2319 /* Set a flag for fast lookup after adding the first toggle reference */
2320 if (tstack->n_toggle_refs == 1)
2321 g_datalist_set_flags (&object->qdata, OBJECT_HAS_TOGGLE_REF_FLAG);
2323 tstack->toggle_refs[i].notify = notify;
2324 tstack->toggle_refs[i].data = data;
2325 g_datalist_id_set_data_full (&object->qdata, quark_toggle_refs, tstack,
2326 (GDestroyNotify)g_free);
2330 * g_object_remove_toggle_ref:
2331 * @object: a #GObject
2332 * @notify: a function to call when this reference is the
2333 * last reference to the object, or is no longer
2334 * the last reference.
2335 * @data: data to pass to @notify
2337 * Removes a reference added with g_object_add_toggle_ref(). The
2338 * reference count of the object is decreased by one.
2340 * Since: 2.8
2342 void
2343 g_object_remove_toggle_ref (GObject *object,
2344 GToggleNotify notify,
2345 gpointer data)
2347 ToggleRefStack *tstack;
2348 gboolean found_one = FALSE;
2350 g_return_if_fail (G_IS_OBJECT (object));
2351 g_return_if_fail (notify != NULL);
2353 tstack = g_datalist_id_get_data (&object->qdata, quark_toggle_refs);
2354 if (tstack)
2356 guint i;
2358 for (i = 0; i < tstack->n_toggle_refs; i++)
2359 if (tstack->toggle_refs[i].notify == notify &&
2360 tstack->toggle_refs[i].data == data)
2362 found_one = TRUE;
2363 tstack->n_toggle_refs -= 1;
2364 if (i != tstack->n_toggle_refs)
2365 tstack->toggle_refs[i] = tstack->toggle_refs[tstack->n_toggle_refs];
2367 if (tstack->n_toggle_refs == 0)
2368 g_datalist_unset_flags (&object->qdata, OBJECT_HAS_TOGGLE_REF_FLAG);
2370 g_object_unref (object);
2372 break;
2376 if (!found_one)
2377 g_warning ("%s: couldn't find toggle ref %p(%p)", G_STRFUNC, notify, data);
2381 * g_object_ref:
2382 * @object: a #GObject
2384 * Increases the reference count of @object.
2386 * Returns: the same @object
2388 gpointer
2389 g_object_ref (gpointer _object)
2391 GObject *object = _object;
2392 gint old_val;
2394 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
2395 g_return_val_if_fail (object->ref_count > 0, NULL);
2397 #ifdef G_ENABLE_DEBUG
2398 if (g_trap_object_ref == object)
2399 G_BREAKPOINT ();
2400 #endif /* G_ENABLE_DEBUG */
2403 old_val = g_atomic_int_exchange_and_add ((int *)&object->ref_count, 1);
2405 if (old_val == 1 && OBJECT_HAS_TOGGLE_REF (object))
2406 toggle_refs_notify (object, FALSE);
2408 return object;
2412 * g_object_unref:
2413 * @object: a #GObject
2415 * Decreases the reference count of @object. When its reference count
2416 * drops to 0, the object is finalized (i.e. its memory is freed).
2418 void
2419 g_object_unref (gpointer _object)
2421 GObject *object = _object;
2422 gint old_ref;
2423 gboolean is_zero;
2425 g_return_if_fail (G_IS_OBJECT (object));
2426 g_return_if_fail (object->ref_count > 0);
2428 #ifdef G_ENABLE_DEBUG
2429 if (g_trap_object_ref == object)
2430 G_BREAKPOINT ();
2431 #endif /* G_ENABLE_DEBUG */
2433 /* here we want to atomically do: if (ref_count>1) { ref_count--; return; } */
2434 retry_atomic_decrement1:
2435 old_ref = g_atomic_int_get (&object->ref_count);
2436 if (old_ref > 1)
2438 /* valid if last 2 refs are owned by this call to unref and the toggle_ref */
2439 gboolean has_toggle_ref = OBJECT_HAS_TOGGLE_REF (object);
2441 if (!g_atomic_int_compare_and_exchange ((int *)&object->ref_count, old_ref, old_ref - 1))
2442 goto retry_atomic_decrement1;
2444 /* if we went from 2->1 we need to notify toggle refs if any */
2445 if (old_ref == 2 && has_toggle_ref) /* The last ref being held in this case is owned by the toggle_ref */
2446 toggle_refs_notify (object, TRUE);
2448 else
2450 /* we are about tp remove the last reference */
2451 G_OBJECT_GET_CLASS (object)->dispose (object);
2453 /* may have been re-referenced meanwhile */
2454 retry_atomic_decrement2:
2455 old_ref = g_atomic_int_get ((int *)&object->ref_count);
2456 if (old_ref > 1)
2458 /* valid if last 2 refs are owned by this call to unref and the toggle_ref */
2459 gboolean has_toggle_ref = OBJECT_HAS_TOGGLE_REF (object);
2461 if (!g_atomic_int_compare_and_exchange ((int *)&object->ref_count, old_ref, old_ref - 1))
2462 goto retry_atomic_decrement2;
2464 /* if we went from 2->1 we need to notify toggle refs if any */
2465 if (old_ref == 2 && has_toggle_ref) /* The last ref being held in this case is owned by the toggle_ref */
2466 toggle_refs_notify (object, TRUE);
2468 return;
2471 /* we are still in the process of taking away the last ref */
2472 g_datalist_id_set_data (&object->qdata, quark_closure_array, NULL);
2473 g_signal_handlers_destroy (object);
2474 g_datalist_id_set_data (&object->qdata, quark_weak_refs, NULL);
2476 /* decrement the last reference */
2477 is_zero = g_atomic_int_dec_and_test ((int *)&object->ref_count);
2479 /* may have been re-referenced meanwhile */
2480 if (G_LIKELY (is_zero))
2482 G_OBJECT_GET_CLASS (object)->finalize (object);
2483 #ifdef G_ENABLE_DEBUG
2484 IF_DEBUG (OBJECTS)
2486 /* catch objects not chaining finalize handlers */
2487 G_LOCK (debug_objects);
2488 g_assert (g_hash_table_lookup (debug_objects_ht, object) == NULL);
2489 G_UNLOCK (debug_objects);
2491 #endif /* G_ENABLE_DEBUG */
2492 g_type_free_instance ((GTypeInstance*) object);
2498 * g_object_get_qdata:
2499 * @object: The GObject to get a stored user data pointer from
2500 * @quark: A #GQuark, naming the user data pointer
2502 * This function gets back user data pointers stored via
2503 * g_object_set_qdata().
2505 * Returns: The user data pointer set, or %NULL
2507 gpointer
2508 g_object_get_qdata (GObject *object,
2509 GQuark quark)
2511 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
2513 return quark ? g_datalist_id_get_data (&object->qdata, quark) : NULL;
2517 * g_object_set_qdata:
2518 * @object: The GObject to set store a user data pointer
2519 * @quark: A #GQuark, naming the user data pointer
2520 * @data: An opaque user data pointer
2522 * This sets an opaque, named pointer on an object.
2523 * The name is specified through a #GQuark (retrived e.g. via
2524 * g_quark_from_static_string()), and the pointer
2525 * can be gotten back from the @object with g_object_get_qdata()
2526 * until the @object is finalized.
2527 * Setting a previously set user data pointer, overrides (frees)
2528 * the old pointer set, using #NULL as pointer essentially
2529 * removes the data stored.
2531 void
2532 g_object_set_qdata (GObject *object,
2533 GQuark quark,
2534 gpointer data)
2536 g_return_if_fail (G_IS_OBJECT (object));
2537 g_return_if_fail (quark > 0);
2539 g_datalist_id_set_data (&object->qdata, quark, data);
2543 * g_object_set_qdata_full:
2544 * @object: The GObject to set store a user data pointer
2545 * @quark: A #GQuark, naming the user data pointer
2546 * @data: An opaque user data pointer
2547 * @destroy: Function to invoke with @data as argument, when @data
2548 * needs to be freed
2550 * This function works like g_object_set_qdata(), but in addition,
2551 * a void (*destroy) (gpointer) function may be specified which is
2552 * called with @data as argument when the @object is finalized, or
2553 * the data is being overwritten by a call to g_object_set_qdata()
2554 * with the same @quark.
2556 void
2557 g_object_set_qdata_full (GObject *object,
2558 GQuark quark,
2559 gpointer data,
2560 GDestroyNotify destroy)
2562 g_return_if_fail (G_IS_OBJECT (object));
2563 g_return_if_fail (quark > 0);
2565 g_datalist_id_set_data_full (&object->qdata, quark, data,
2566 data ? destroy : (GDestroyNotify) NULL);
2570 * g_object_steal_qdata:
2571 * @object: The GObject to get a stored user data pointer from
2572 * @quark: A #GQuark, naming the user data pointer
2574 * This function gets back user data pointers stored via
2575 * g_object_set_qdata() and removes the @data from object
2576 * without invoking its destroy() function (if any was
2577 * set).
2578 * Usually, calling this function is only required to update
2579 * user data pointers with a destroy notifier, for example:
2580 * |[
2581 * void
2582 * object_add_to_user_list (GObject *object,
2583 * const gchar *new_string)
2585 * // the quark, naming the object data
2586 * GQuark quark_string_list = g_quark_from_static_string ("my-string-list");
2587 * // retrive the old string list
2588 * GList *list = g_object_steal_qdata (object, quark_string_list);
2590 * // prepend new string
2591 * list = g_list_prepend (list, g_strdup (new_string));
2592 * // this changed 'list', so we need to set it again
2593 * g_object_set_qdata_full (object, quark_string_list, list, free_string_list);
2595 * static void
2596 * free_string_list (gpointer data)
2598 * GList *node, *list = data;
2600 * for (node = list; node; node = node->next)
2601 * g_free (node->data);
2602 * g_list_free (list);
2604 * ]|
2605 * Using g_object_get_qdata() in the above example, instead of
2606 * g_object_steal_qdata() would have left the destroy function set,
2607 * and thus the partial string list would have been freed upon
2608 * g_object_set_qdata_full().
2610 * Returns: The user data pointer set, or %NULL
2612 gpointer
2613 g_object_steal_qdata (GObject *object,
2614 GQuark quark)
2616 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
2617 g_return_val_if_fail (quark > 0, NULL);
2619 return g_datalist_id_remove_no_notify (&object->qdata, quark);
2623 * g_object_get_data:
2624 * @object: #GObject containing the associations
2625 * @key: name of the key for that association
2627 * Gets a named field from the objects table of associations (see g_object_set_data()).
2629 * Returns: the data if found, or %NULL if no such data exists.
2631 gpointer
2632 g_object_get_data (GObject *object,
2633 const gchar *key)
2635 GQuark quark;
2637 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
2638 g_return_val_if_fail (key != NULL, NULL);
2640 quark = g_quark_try_string (key);
2642 return quark ? g_datalist_id_get_data (&object->qdata, quark) : NULL;
2646 * g_object_set_data:
2647 * @object: #GObject containing the associations.
2648 * @key: name of the key
2649 * @data: data to associate with that key
2651 * Each object carries around a table of associations from
2652 * strings to pointers. This function lets you set an association.
2654 * If the object already had an association with that name,
2655 * the old association will be destroyed.
2657 void
2658 g_object_set_data (GObject *object,
2659 const gchar *key,
2660 gpointer data)
2662 g_return_if_fail (G_IS_OBJECT (object));
2663 g_return_if_fail (key != NULL);
2665 g_datalist_id_set_data (&object->qdata, g_quark_from_string (key), data);
2669 * g_object_set_data_full:
2670 * @object: #GObject containing the associations
2671 * @key: name of the key
2672 * @data: data to associate with that key
2673 * @destroy: function to call when the association is destroyed
2675 * Like g_object_set_data() except it adds notification
2676 * for when the association is destroyed, either by setting it
2677 * to a different value or when the object is destroyed.
2679 * Note that the @destroy callback is not called if @data is %NULL.
2681 void
2682 g_object_set_data_full (GObject *object,
2683 const gchar *key,
2684 gpointer data,
2685 GDestroyNotify destroy)
2687 g_return_if_fail (G_IS_OBJECT (object));
2688 g_return_if_fail (key != NULL);
2690 g_datalist_id_set_data_full (&object->qdata, g_quark_from_string (key), data,
2691 data ? destroy : (GDestroyNotify) NULL);
2695 * g_object_steal_data:
2696 * @object: #GObject containing the associations
2697 * @key: name of the key
2699 * Remove a specified datum from the object's data associations,
2700 * without invoking the association's destroy handler.
2702 * Returns: the data if found, or %NULL if no such data exists.
2704 gpointer
2705 g_object_steal_data (GObject *object,
2706 const gchar *key)
2708 GQuark quark;
2710 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
2711 g_return_val_if_fail (key != NULL, NULL);
2713 quark = g_quark_try_string (key);
2715 return quark ? g_datalist_id_remove_no_notify (&object->qdata, quark) : NULL;
2718 static void
2719 g_value_object_init (GValue *value)
2721 value->data[0].v_pointer = NULL;
2724 static void
2725 g_value_object_free_value (GValue *value)
2727 if (value->data[0].v_pointer)
2728 g_object_unref (value->data[0].v_pointer);
2731 static void
2732 g_value_object_copy_value (const GValue *src_value,
2733 GValue *dest_value)
2735 if (src_value->data[0].v_pointer)
2736 dest_value->data[0].v_pointer = g_object_ref (src_value->data[0].v_pointer);
2737 else
2738 dest_value->data[0].v_pointer = NULL;
2741 static void
2742 g_value_object_transform_value (const GValue *src_value,
2743 GValue *dest_value)
2745 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)))
2746 dest_value->data[0].v_pointer = g_object_ref (src_value->data[0].v_pointer);
2747 else
2748 dest_value->data[0].v_pointer = NULL;
2751 static gpointer
2752 g_value_object_peek_pointer (const GValue *value)
2754 return value->data[0].v_pointer;
2757 static gchar*
2758 g_value_object_collect_value (GValue *value,
2759 guint n_collect_values,
2760 GTypeCValue *collect_values,
2761 guint collect_flags)
2763 if (collect_values[0].v_pointer)
2765 GObject *object = collect_values[0].v_pointer;
2767 if (object->g_type_instance.g_class == NULL)
2768 return g_strconcat ("invalid unclassed object pointer for value type `",
2769 G_VALUE_TYPE_NAME (value),
2770 "'",
2771 NULL);
2772 else if (!g_value_type_compatible (G_OBJECT_TYPE (object), G_VALUE_TYPE (value)))
2773 return g_strconcat ("invalid object type `",
2774 G_OBJECT_TYPE_NAME (object),
2775 "' for value type `",
2776 G_VALUE_TYPE_NAME (value),
2777 "'",
2778 NULL);
2779 /* never honour G_VALUE_NOCOPY_CONTENTS for ref-counted types */
2780 value->data[0].v_pointer = g_object_ref (object);
2782 else
2783 value->data[0].v_pointer = NULL;
2785 return NULL;
2788 static gchar*
2789 g_value_object_lcopy_value (const GValue *value,
2790 guint n_collect_values,
2791 GTypeCValue *collect_values,
2792 guint collect_flags)
2794 GObject **object_p = collect_values[0].v_pointer;
2796 if (!object_p)
2797 return g_strdup_printf ("value location for `%s' passed as NULL", G_VALUE_TYPE_NAME (value));
2799 if (!value->data[0].v_pointer)
2800 *object_p = NULL;
2801 else if (collect_flags & G_VALUE_NOCOPY_CONTENTS)
2802 *object_p = value->data[0].v_pointer;
2803 else
2804 *object_p = g_object_ref (value->data[0].v_pointer);
2806 return NULL;
2810 * g_value_set_object:
2811 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
2812 * @v_object: object value to be set
2814 * Set the contents of a %G_TYPE_OBJECT derived #GValue to @v_object.
2816 * g_value_set_object() increases the reference count of @v_object
2817 * (the #GValue holds a reference to @v_object). If you do not wish
2818 * to increase the reference count of the object (i.e. you wish to
2819 * pass your current reference to the #GValue because you no longer
2820 * need it), use g_value_take_object() instead.
2822 * It is important that your #GValue holds a reference to @v_object (either its
2823 * own, or one it has taken) to ensure that the object won't be destroyed while
2824 * the #GValue still exists).
2826 void
2827 g_value_set_object (GValue *value,
2828 gpointer v_object)
2830 GObject *old;
2832 g_return_if_fail (G_VALUE_HOLDS_OBJECT (value));
2834 old = value->data[0].v_pointer;
2836 if (v_object)
2838 g_return_if_fail (G_IS_OBJECT (v_object));
2839 g_return_if_fail (g_value_type_compatible (G_OBJECT_TYPE (v_object), G_VALUE_TYPE (value)));
2841 value->data[0].v_pointer = v_object;
2842 g_object_ref (value->data[0].v_pointer);
2844 else
2845 value->data[0].v_pointer = NULL;
2847 if (old)
2848 g_object_unref (old);
2852 * g_value_set_object_take_ownership:
2853 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
2854 * @v_object: object value to be set
2856 * This is an internal function introduced mainly for C marshallers.
2858 * Deprecated: 2.4: Use g_value_take_object() instead.
2860 void
2861 g_value_set_object_take_ownership (GValue *value,
2862 gpointer v_object)
2864 g_value_take_object (value, v_object);
2868 * g_value_take_object:
2869 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
2870 * @v_object: object value to be set
2872 * Sets the contents of a %G_TYPE_OBJECT derived #GValue to @v_object
2873 * and takes over the ownership of the callers reference to @v_object;
2874 * the caller doesn't have to unref it any more (i.e. the reference
2875 * count of the object is not increased).
2877 * If you want the #GValue to hold its own reference to @v_object, use
2878 * g_value_set_object() instead.
2880 * Since: 2.4
2882 void
2883 g_value_take_object (GValue *value,
2884 gpointer v_object)
2886 g_return_if_fail (G_VALUE_HOLDS_OBJECT (value));
2888 if (value->data[0].v_pointer)
2890 g_object_unref (value->data[0].v_pointer);
2891 value->data[0].v_pointer = NULL;
2894 if (v_object)
2896 g_return_if_fail (G_IS_OBJECT (v_object));
2897 g_return_if_fail (g_value_type_compatible (G_OBJECT_TYPE (v_object), G_VALUE_TYPE (value)));
2899 value->data[0].v_pointer = v_object; /* we take over the reference count */
2904 * g_value_get_object:
2905 * @value: a valid #GValue of %G_TYPE_OBJECT derived type
2907 * Get the contents of a %G_TYPE_OBJECT derived #GValue.
2909 * Returns: object contents of @value
2911 gpointer
2912 g_value_get_object (const GValue *value)
2914 g_return_val_if_fail (G_VALUE_HOLDS_OBJECT (value), NULL);
2916 return value->data[0].v_pointer;
2920 * g_value_dup_object:
2921 * @value: a valid #GValue whose type is derived from %G_TYPE_OBJECT
2923 * Get the contents of a %G_TYPE_OBJECT derived #GValue, increasing
2924 * its reference count.
2926 * Returns: object content of @value, should be unreferenced when no
2927 * longer needed.
2929 gpointer
2930 g_value_dup_object (const GValue *value)
2932 g_return_val_if_fail (G_VALUE_HOLDS_OBJECT (value), NULL);
2934 return value->data[0].v_pointer ? g_object_ref (value->data[0].v_pointer) : NULL;
2938 * g_signal_connect_object:
2939 * @instance: the instance to connect to.
2940 * @detailed_signal: a string of the form "signal-name::detail".
2941 * @c_handler: the #GCallback to connect.
2942 * @gobject: the object to pass as data to @c_handler.
2943 * @connect_flags: a combination of #GConnnectFlags.
2945 * This is similar to g_signal_connect_data(), but uses a closure which
2946 * ensures that the @gobject stays alive during the call to @c_handler
2947 * by temporarily adding a reference count to @gobject.
2949 * Note that there is a bug in GObject that makes this function
2950 * much less useful than it might seem otherwise. Once @gobject is
2951 * disposed, the callback will no longer be called, but, the signal
2952 * handler is <emphasis>not</emphasis> currently disconnected. If the
2953 * @instance is itself being freed at the same time than this doesn't
2954 * matter, since the signal will automatically be removed, but
2955 * if @instance persists, then the signal handler will leak. You
2956 * should not remove the signal yourself because in a future versions of
2957 * GObject, the handler <emphasis>will</emphasis> automatically
2958 * be disconnected.
2960 * It's possible to work around this problem in a way that will
2961 * continue to work with future versions of GObject by checking
2962 * that the signal handler is still connected before disconnected it:
2963 * <informalexample><programlisting>
2964 * if (g_signal_handler_is_connected (instance, id))
2965 * g_signal_handler_disconnect (instance, id);
2966 * </programlisting></informalexample>
2968 * Returns: the handler id.
2970 gulong
2971 g_signal_connect_object (gpointer instance,
2972 const gchar *detailed_signal,
2973 GCallback c_handler,
2974 gpointer gobject,
2975 GConnectFlags connect_flags)
2977 g_return_val_if_fail (G_TYPE_CHECK_INSTANCE (instance), 0);
2978 g_return_val_if_fail (detailed_signal != NULL, 0);
2979 g_return_val_if_fail (c_handler != NULL, 0);
2981 if (gobject)
2983 GClosure *closure;
2985 g_return_val_if_fail (G_IS_OBJECT (gobject), 0);
2987 closure = ((connect_flags & G_CONNECT_SWAPPED) ? g_cclosure_new_object_swap : g_cclosure_new_object) (c_handler, gobject);
2989 return g_signal_connect_closure (instance, detailed_signal, closure, connect_flags & G_CONNECT_AFTER);
2991 else
2992 return g_signal_connect_data (instance, detailed_signal, c_handler, NULL, NULL, connect_flags);
2995 typedef struct {
2996 GObject *object;
2997 guint n_closures;
2998 GClosure *closures[1]; /* flexible array */
2999 } CArray;
3000 /* don't change this structure without supplying an accessor for
3001 * watched closures, e.g.:
3002 * GSList* g_object_list_watched_closures (GObject *object)
3004 * CArray *carray;
3005 * g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3006 * carray = g_object_get_data (object, "GObject-closure-array");
3007 * if (carray)
3009 * GSList *slist = NULL;
3010 * guint i;
3011 * for (i = 0; i < carray->n_closures; i++)
3012 * slist = g_slist_prepend (slist, carray->closures[i]);
3013 * return slist;
3015 * return NULL;
3019 static void
3020 object_remove_closure (gpointer data,
3021 GClosure *closure)
3023 GObject *object = data;
3024 CArray *carray = g_object_get_qdata (object, quark_closure_array);
3025 guint i;
3027 for (i = 0; i < carray->n_closures; i++)
3028 if (carray->closures[i] == closure)
3030 carray->n_closures--;
3031 if (i < carray->n_closures)
3032 carray->closures[i] = carray->closures[carray->n_closures];
3033 return;
3035 g_assert_not_reached ();
3038 static void
3039 destroy_closure_array (gpointer data)
3041 CArray *carray = data;
3042 GObject *object = carray->object;
3043 guint i, n = carray->n_closures;
3045 for (i = 0; i < n; i++)
3047 GClosure *closure = carray->closures[i];
3049 /* removing object_remove_closure() upfront is probably faster than
3050 * letting it fiddle with quark_closure_array which is empty anyways
3052 g_closure_remove_invalidate_notifier (closure, object, object_remove_closure);
3053 g_closure_invalidate (closure);
3055 g_free (carray);
3059 * g_object_watch_closure:
3060 * @object: GObject restricting lifetime of @closure
3061 * @closure: GClosure to watch
3063 * This function essentially limits the life time of the @closure to
3064 * the life time of the object. That is, when the object is finalized,
3065 * the @closure is invalidated by calling g_closure_invalidate() on
3066 * it, in order to prevent invocations of the closure with a finalized
3067 * (nonexisting) object. Also, g_object_ref() and g_object_unref() are
3068 * added as marshal guards to the @closure, to ensure that an extra
3069 * reference count is held on @object during invocation of the
3070 * @closure. Usually, this function will be called on closures that
3071 * use this @object as closure data.
3073 void
3074 g_object_watch_closure (GObject *object,
3075 GClosure *closure)
3077 CArray *carray;
3078 guint i;
3080 g_return_if_fail (G_IS_OBJECT (object));
3081 g_return_if_fail (closure != NULL);
3082 g_return_if_fail (closure->is_invalid == FALSE);
3083 g_return_if_fail (closure->in_marshal == FALSE);
3084 g_return_if_fail (object->ref_count > 0); /* this doesn't work on finalizing objects */
3086 g_closure_add_invalidate_notifier (closure, object, object_remove_closure);
3087 g_closure_add_marshal_guards (closure,
3088 object, (GClosureNotify) g_object_ref,
3089 object, (GClosureNotify) g_object_unref);
3090 carray = g_datalist_id_remove_no_notify (&object->qdata, quark_closure_array);
3091 if (!carray)
3093 carray = g_renew (CArray, NULL, 1);
3094 carray->object = object;
3095 carray->n_closures = 1;
3096 i = 0;
3098 else
3100 i = carray->n_closures++;
3101 carray = g_realloc (carray, sizeof (*carray) + sizeof (carray->closures[0]) * i);
3103 carray->closures[i] = closure;
3104 g_datalist_id_set_data_full (&object->qdata, quark_closure_array, carray, destroy_closure_array);
3108 * g_closure_new_object:
3109 * @sizeof_closure: the size of the structure to allocate, must be at least
3110 * <literal>sizeof (GClosure)</literal>
3111 * @object: a #GObject pointer to store in the @data field of the newly
3112 * allocated #GClosure
3114 * A variant of g_closure_new_simple() which stores @object in the
3115 * @data field of the closure and calls g_object_watch_closure() on
3116 * @object and the created closure. This function is mainly useful
3117 * when implementing new types of closures.
3119 * Returns: a newly allocated #GClosure
3121 GClosure*
3122 g_closure_new_object (guint sizeof_closure,
3123 GObject *object)
3125 GClosure *closure;
3127 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3128 g_return_val_if_fail (object->ref_count > 0, NULL); /* this doesn't work on finalizing objects */
3130 closure = g_closure_new_simple (sizeof_closure, object);
3131 g_object_watch_closure (object, closure);
3133 return closure;
3137 * g_cclosure_new_object:
3138 * @callback_func: the function to invoke
3139 * @object: a #GObject pointer to pass to @callback_func
3141 * A variant of g_cclosure_new() which uses @object as @user_data and
3142 * calls g_object_watch_closure() on @object and the created
3143 * closure. This function is useful when you have a callback closely
3144 * associated with a #GObject, and want the callback to no longer run
3145 * after the object is is freed.
3147 * Returns: a new #GCClosure
3149 GClosure*
3150 g_cclosure_new_object (GCallback callback_func,
3151 GObject *object)
3153 GClosure *closure;
3155 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3156 g_return_val_if_fail (object->ref_count > 0, NULL); /* this doesn't work on finalizing objects */
3157 g_return_val_if_fail (callback_func != NULL, NULL);
3159 closure = g_cclosure_new (callback_func, object, NULL);
3160 g_object_watch_closure (object, closure);
3162 return closure;
3166 * g_cclosure_new_object_swap:
3167 * @callback_func: the function to invoke
3168 * @object: a #GObject pointer to pass to @callback_func
3170 * A variant of g_cclosure_new_swap() which uses @object as @user_data
3171 * and calls g_object_watch_closure() on @object and the created
3172 * closure. This function is useful when you have a callback closely
3173 * associated with a #GObject, and want the callback to no longer run
3174 * after the object is is freed.
3176 * Returns: a new #GCClosure
3178 GClosure*
3179 g_cclosure_new_object_swap (GCallback callback_func,
3180 GObject *object)
3182 GClosure *closure;
3184 g_return_val_if_fail (G_IS_OBJECT (object), NULL);
3185 g_return_val_if_fail (object->ref_count > 0, NULL); /* this doesn't work on finalizing objects */
3186 g_return_val_if_fail (callback_func != NULL, NULL);
3188 closure = g_cclosure_new_swap (callback_func, object, NULL);
3189 g_object_watch_closure (object, closure);
3191 return closure;
3194 gsize
3195 g_object_compat_control (gsize what,
3196 gpointer data)
3198 switch (what)
3200 gpointer *pp;
3201 case 1: /* floating base type */
3202 return G_TYPE_INITIALLY_UNOWNED;
3203 case 2: /* FIXME: remove this once GLib/Gtk+ break ABI again */
3204 floating_flag_handler = (guint(*)(GObject*,gint)) data;
3205 return 1;
3206 case 3: /* FIXME: remove this once GLib/Gtk+ break ABI again */
3207 pp = data;
3208 *pp = floating_flag_handler;
3209 return 1;
3210 default:
3211 return 0;
3215 G_DEFINE_TYPE (GInitiallyUnowned, g_initially_unowned, G_TYPE_OBJECT);
3217 static void
3218 g_initially_unowned_init (GInitiallyUnowned *object)
3220 g_object_force_floating (object);
3223 static void
3224 g_initially_unowned_class_init (GInitiallyUnownedClass *klass)
3228 #define __G_OBJECT_C__
3229 #include "gobjectaliasdef.c"