Memory-managed wrapper type.

Type class for types which can be safely cast to Object, for instance with toObject.

Cast to Object, for types for which this is known to be safe. For general casts, use castTo.

A convenience alias for Nothing :: Maybe Object.

Creates a binding between sourceProperty on source and targetProperty on target. Whenever the sourceProperty is changed the targetProperty is updated using the same value. For instance:

 g_object_bind_property (action, "active", widget, "sensitive", 0);

Will result in the "sensitive" property of the widget Object instance to be updated with the same value of the "active" property of the action Object instance.

If flags contains BindingFlagsBidirectional then the binding will be mutual: if targetProperty on target changes then the sourceProperty on source will be updated as well.

The binding will automatically be removed when either the source or the target instances are finalized. To remove the binding without affecting the source and the target you can just call objectUnref on the returned Binding instance.

A Object can have multiple bindings.

Since: 2.26

Creates a binding between sourceProperty on source and targetProperty on target, allowing you to set the transformation functions to be used by the binding.

This function is the language bindings friendly version of g_object_bind_property_full(), using GClosures instead of function pointers.

Since: 2.26

No description available in the introspection data.

This function is intended for Object implementations to re-enforce a [floating][floating-ref] object reference. Doing this is seldom required: all GInitiallyUnowneds are created with a floating reference which usually just needs to be sunken by calling objectRefSink.

Since: 2.10

Increases the freeze count on object. If the freeze count is non-zero, the emission of "notify" signals on object is stopped. The signals are queued until the freeze count is decreased to zero. Duplicate notifications are squashed so that at most one notify signal is emitted for each property modified while the object is frozen.

This is necessary for accessors that modify multiple properties to prevent premature notification while the object is still being modified.

Gets a named field from the objects table of associations (see objectSetData).

Gets a property of an object. value must have been initialized to the expected type of the property (or a type to which the expected type can be transformed) using valueInit.

In general, a copy is made of the property contents and the caller is responsible for freeing the memory by calling valueUnset.

Note that objectGetProperty is really intended for language bindings, g_object_get() is much more convenient for C programming.

This function gets back user data pointers stored via g_object_set_qdata().

Gets nProperties properties for an object. Obtained properties will be set to values. All properties must be valid. Warnings will be emitted and undefined behaviour may result if invalid properties are passed in.

Since: 2.54

Find the ParamSpec with the given name for an interface. Generally, the interface vtable passed in as gIface will be the default vtable from typeDefaultInterfaceRef, or, if you know the interface has already been loaded, typeDefaultInterfacePeek.

Since: 2.4

Add a property to an interface; this is only useful for interfaces that are added to GObject-derived types. Adding a property to an interface forces all objects classes with that interface to have a compatible property. The compatible property could be a newly created ParamSpec, but normally objectClassOverrideProperty will be used so that the object class only needs to provide an implementation and inherits the property description, default value, bounds, and so forth from the interface property.

This function is meant to be called from the interface's default vtable initialization function (the classInit member of TypeInfo.) It must not be called after after classInit has been called for any object types implementing this interface.

If pspec is a floating reference, it will be consumed.

Since: 2.4

Checks whether object has a [floating][floating-ref] reference.

Since: 2.10

Creates a new instance of a Object subtype and sets its properties.

Construction parameters (see G_PARAM_CONSTRUCT, G_PARAM_CONSTRUCT_ONLY) which are not explicitly specified are set to their default values.

Emits a "notify" signal for the property propertyName on object.

When possible, eg. when signaling a property change from within the class that registered the property, you should use objectNotifyByPspec instead.

Note that emission of the notify signal may be blocked with objectFreezeNotify. In this case, the signal emissions are queued and will be emitted (in reverse order) when objectThawNotify is called.

Emits a "notify" signal for the property specified by pspec on object.

This function omits the property name lookup, hence it is faster than objectNotify.

One way to avoid using objectNotify from within the class that registered the properties, and using objectNotifyByPspec instead, is to store the GParamSpec used with objectClassInstallProperty inside a static array, e.g.:

C code

 enum
 {
   PROP_0,
   PROP_FOO,
   PROP_LAST
 };

 static GParamSpec *properties[PROP_LAST];

 static void
 my_object_class_init (MyObjectClass *klass)
 {
   properties[PROP_FOO] = g_param_spec_int ("foo", "Foo", "The foo",
                                            0, 100,
                                            50,
                                            G_PARAM_READWRITE);
   g_object_class_install_property (gobject_class,
                                    PROP_FOO,
                                    properties[PROP_FOO]);
 }

and then notify a change on the "foo" property with:

C code

 g_object_notify_by_pspec (self, properties[PROP_FOO]);

Since: 2.26

Increases the reference count of object.

Since GLib 2.56, if GLIB_VERSION_MAX_ALLOWED is 2.56 or greater, the type of object will be propagated to the return type (using the GCC typeof() extension), so any casting the caller needs to do on the return type must be explicit.

Increase the reference count of object, and possibly remove the [floating][floating-ref] reference, if object has a floating reference.

In other words, if the object is floating, then this call "assumes ownership" of the floating reference, converting it to a normal reference by clearing the floating flag while leaving the reference count unchanged. If the object is not floating, then this call adds a new normal reference increasing the reference count by one.

Since GLib 2.56, the type of object will be propagated to the return type under the same conditions as for objectRef.

Since: 2.10

Releases all references to other objects. This can be used to break reference cycles.

This function should only be called from object system implementations.

Each object carries around a table of associations from strings to pointers. This function lets you set an association.

If the object already had an association with that name, the old association will be destroyed.

Like objectSetData except it adds notification for when the association is destroyed, either by setting it to a different value or when the object is destroyed.

Note that the destroy callback is not called if data is Nothing.

Sets a property on an object.

Remove a specified datum from the object's data associations, without invoking the association's destroy handler.

This function gets back user data pointers stored via g_object_set_qdata() and removes the data from object without invoking its destroy() function (if any was set). Usually, calling this function is only required to update user data pointers with a destroy notifier, for example:

C code

void
object_add_to_user_list (GObject     *object,
                         const gchar *new_string)
{
  // the quark, naming the object data
  GQuark quark_string_list = g_quark_from_static_string ("my-string-list");
  // retrive the old string list
  GList *list = g_object_steal_qdata (object, quark_string_list);

  // prepend new string
  list = g_list_prepend (list, g_strdup (new_string));
  // this changed 'list', so we need to set it again
  g_object_set_qdata_full (object, quark_string_list, list, free_string_list);
}
static void
free_string_list (gpointer data)
{
  GList *node, *list = data;

  for (node = list; node; node = node->next)
    g_free (node->data);
  g_list_free (list);
}

Using objectGetQdata in the above example, instead of objectStealQdata would have left the destroy function set, and thus the partial string list would have been freed upon g_object_set_qdata_full().

Reverts the effect of a previous call to objectFreezeNotify. The freeze count is decreased on object and when it reaches zero, queued "notify" signals are emitted.

Duplicate notifications for each property are squashed so that at most one notify signal is emitted for each property, in the reverse order in which they have been queued.

It is an error to call this function when the freeze count is zero.

Decreases the reference count of object. When its reference count drops to 0, the object is finalized (i.e. its memory is freed).

If the pointer to the Object may be reused in future (for example, if it is an instance variable of another object), it is recommended to clear the pointer to Nothing rather than retain a dangling pointer to a potentially invalid Object instance. Use g_clear_object() for this.

This function essentially limits the life time of the closure to the life time of the object. That is, when the object is finalized, the closure is invalidated by calling closureInvalidate on it, in order to prevent invocations of the closure with a finalized (nonexisting) object. Also, objectRef and objectUnref are added as marshal guards to the closure, to ensure that an extra reference count is held on object during invocation of the closure. Usually, this function will be called on closures that use this object as closure data.

Type for the callback on the (unwrapped) C side.

The notify signal is emitted on an object when one of its properties has its value set through objectSetProperty, g_object_set(), et al.

Note that getting this signal doesn’t itself guarantee that the value of the property has actually changed. When it is emitted is determined by the derived GObject class. If the implementor did not create the property with ParamFlagsExplicitNotify, then any call to objectSetProperty results in notify being emitted, even if the new value is the same as the old. If they did pass ParamFlagsExplicitNotify, then this signal is emitted only when they explicitly call objectNotify or objectNotifyByPspec, and common practice is to do that only when the value has actually changed.

This signal is typically used to obtain change notification for a single property, by specifying the property name as a detail in the g_signal_connect() call, like this:

C code

g_signal_connect (text_view->buffer, "notify::paste-target-list",
                  G_CALLBACK (gtk_text_view_target_list_notify),
                  text_view)

It is important to note that you must use [canonical parameter names][canonical-parameter-names] as detail strings for the notify signal.

Connect a signal handler for the notify signal, to be run after the default handler. When overloading is enabled, this is equivalent to

after object #notify callback

This signal admits a optional parameter detail. If it's not Nothing, we will connect to “notify::detail” instead.

Wrap the callback into a GClosure.

Generate a function pointer callable from C code, from a C_ObjectNotifyCallback.

A convenience synonym for Nothing :: Maybe ObjectNotifyCallback.

Connect a signal handler for the notify signal, to be run before the default handler. When overloading is enabled, this is equivalent to

on object #notify callback

This signal admits a optional parameter detail. If it's not Nothing, we will connect to “notify::detail” instead.

Wrap a ObjectNotifyCallback into a C_ObjectNotifyCallback.