G_CLOSURE_NEEDS_MARSHAL()

#define	G_CLOSURE_NEEDS_MARSHAL(closure) (((GClosure*) (closure))->marshal == NULL)

Returns TRUE if a GClosureMarshal marshaller has not yet been set on closure. See g_closure_set_marshal().

G_CLOSURE_N_NOTIFIERS()

#define     G_CLOSURE_N_NOTIFIERS(cl)

Returns the total number of notifiers connected with the closure cl. The count includes the meta marshaller, the finalize and invalidate notifiers and the marshal guards. Note that each guard counts as two notifiers. See g_closure_set_meta_marshal(), g_closure_add_finalize_notifier(), g_closure_add_invalidate_notifier() and g_closure_add_marshal_guards().

G_CCLOSURE_SWAP_DATA()

#define	G_CCLOSURE_SWAP_DATA(cclosure)	 (((GClosure*) (closure))->derivative_flag)

Returns whether the user data of the GCClosure should be passed as the first parameter to the callback. See g_cclosure_new_swap().

G_CALLBACK()

#define	G_CALLBACK(f)			 ((GCallback) (f))

Cast a function pointer to a GCallback.

GCallback ()

void        (*GCallback)                    (void);

The type used for callback functions in structure definitions and function signatures. This doesn't mean that all callback functions must take no parameters and return void. The required signature of a callback function is determined by the context in which is used (e.g. the signal to which it is connected). Use G_CALLBACK() to cast the callback function to a GCallback.

GClosure

typedef struct {
  volatile       	guint	 in_marshal : 1;
  volatile       	guint	 is_invalid : 1;
} GClosure;

A GClosure represents a callback supplied by the programmer.

G_TYPE_CLOSURE

#define	G_TYPE_CLOSURE		(g_closure_get_type ())

The GType for GClosure.

GCClosure

typedef struct {
  GClosure	closure;
  gpointer	callback;
} GCClosure;

A GCClosure is a specialization of GClosure for C function callbacks.

GClosureMarshal ()

void        (*GClosureMarshal)              (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

The type used for marshaller functions.

GClosureNotify ()

void        (*GClosureNotify)               (gpointer data,
                                             GClosure *closure);

The type used for the various notification callbacks which can be registered on closures.

g_cclosure_new ()

GClosure*   g_cclosure_new                  (GCallback callback_func,
                                             gpointer user_data,
                                             GClosureNotify destroy_data);

Creates a new closure which invokes callback_func with user_data as the last parameter.

g_cclosure_new_swap ()

GClosure*   g_cclosure_new_swap             (GCallback callback_func,
                                             gpointer user_data,
                                             GClosureNotify destroy_data);

Creates a new closure which invokes callback_func with user_data as the first parameter.

g_cclosure_new_object ()

GClosure*   g_cclosure_new_object           (GCallback callback_func,
                                             GObject *object);

A variant of g_cclosure_new() which uses object as user_data and calls g_object_watch_closure() on object and the created closure. This function is useful when you have a callback closely associated with a GObject, and want the callback to no longer run after the object is is freed.

g_cclosure_new_object_swap ()

GClosure*   g_cclosure_new_object_swap      (GCallback callback_func,
                                             GObject *object);

A variant of g_cclosure_new_swap() which uses object as user_data and calls g_object_watch_closure() on object and the created closure. This function is useful when you have a callback closely associated with a GObject, and want the callback to no longer run after the object is is freed.

g_closure_new_object ()

GClosure*   g_closure_new_object            (guint sizeof_closure,
                                             GObject *object);

A variant of g_closure_new_simple() which stores object in the data field of the closure and calls g_object_watch_closure() on object and the created closure. This function is mainly useful when implementing new types of closures.

g_closure_ref ()

GClosure*   g_closure_ref                   (GClosure *closure);

Increments the reference count on a closure to force it staying alive while the caller holds a pointer to it.

g_closure_sink ()

void        g_closure_sink                  (GClosure *closure);

Takes over the initial ownership of a closure. Each closure is initially created in afloating state, which means that the initial reference count is not owned by any caller. g_closure_sink() checks to see if the object is still floating, and if so, unsets the floating state and decreases the reference count. If the closure is not floating, g_closure_sink() does nothing. The reason for the existance of the floating state is to prevent cumbersome code sequences like:

closure = g_cclosure_new (cb_func, cb_data); 
g_source_set_closure (source, closure); 
g_closure_unref (closure); /* XXX GObject doesn't really need this */

Because g_source_set_closure() (and similar functions) take ownership of the initial reference count, if it is unowned, we instead can write:

g_source_set_closure (source, g_cclosure_new (cb_func, cb_data));

Generally, this function is used together with g_closure_ref(). Ane example of storing a closure for later notification looks like:

static GClosure *notify_closure = NULL;
void
foo_notify_set_closure (GClosure *closure)
{
  if (notify_closure)
    g_closure_unref (notify_closure);
  notify_closure = closure;
  if (notify_closure)
    {
      g_closure_ref (notify_closure);
      g_closure_sink (notify_closure);
    }
}

Because g_closure_sink() may decrement the reference count of a closure (if it hasn't been called on closure yet) just like g_closure_unref(), g_closure_ref() should be called prior to this function.

g_closure_unref ()

void        g_closure_unref                 (GClosure *closure);

Decrements the reference count of a closure after it was previously incremented by the same caller. If no other callers are using the closure, then the closure will be destroyed and freed.

g_closure_invoke ()

void        g_closure_invoke                (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint);

Invokes the closure, i.e. executes the callback represented by the closure.

g_closure_invalidate ()

void        g_closure_invalidate            (GClosure *closure);

Sets a flag on the closure to indicate that it's calling environment has become invalid, and thus causes any future invocations of g_closure_invoke() on this closure to be ignored. Also, invalidation notifiers installed on the closure will be called at this point. Note that unless you are holding a reference to the closure yourself, the invalidation notifiers may unref the closure and cause it to be destroyed, so if you need to access the closure after calling g_closure_invalidate(), make sure that you've previously called g_closure_ref().

Note that g_closure_invalidate() will also be called when the reference count of a closure drops to zero (unless it has already been invalidated before).

g_closure_add_finalize_notifier ()

void        g_closure_add_finalize_notifier (GClosure *closure,
                                             gpointer notify_data,
                                             GClosureNotify notify_func);

Registers a finalization notifier which will be called when the reference count of closure goes down to 0. Multiple finalization notifiers on a single closure are invoked in unspecified order. If a single call to g_closure_unref() results in the closure being both invalidated and finalized, then the invalidate notifiers will be run before the finalize notifiers.

g_closure_add_invalidate_notifier ()

void        g_closure_add_invalidate_notifier
                                            (GClosure *closure,
                                             gpointer notify_data,
                                             GClosureNotify notify_func);

Registers an invalidation notifier which will be called when the closure is invalidated with g_closure_invalidate(). Invalidation notifiers are invoked before finalization notifiers, in an unspecified order.

g_closure_remove_finalize_notifier ()

void        g_closure_remove_finalize_notifier
                                            (GClosure *closure,
                                             gpointer notify_data,
                                             GClosureNotify notify_func);

Removes a finalization notifier. Notifiers are automatically removed after they are run.

g_closure_remove_invalidate_notifier ()

void        g_closure_remove_invalidate_notifier
                                            (GClosure *closure,
                                             gpointer notify_data,
                                             GClosureNotify notify_func);

Removes a invalidation notifier. Notifiers are automatically removed after they are run.

g_closure_new_simple ()

GClosure*   g_closure_new_simple            (guint sizeof_closure,
                                             gpointer data);

Allocates a struct of the given size and initializes the initial part as a GClosure. This function is mainly useful when implementing new types of closures.

typedef struct _MyClosure MyClosure;
struct _MyClosure 
{
  GClosure closure;
  /* extra data goes here */
};
    

static void
my_closure_finalize (gpointer  notify_data, 
                     GClosure *closure)
{
  MyClosure *my_closure = (MyClosure *)closure;

  /* free extra data here */
}

MyClosure *my_closure_new (gpointer data)
{
  GClosure *closure;
  MyClosure *my_closure;
  
  closure = g_closure_new_simple (sizeof (MyClosure), data);
  my_closure = (MyClosure *) closure;

  / initialize extra data here */

  g_closure_add_finalize_notifier (closure, notify_data,
                                   my_closure_finalize);
  return my_closure;
}

g_closure_set_marshal ()

void        g_closure_set_marshal           (GClosure *closure,
                                             GClosureMarshal marshal);

Sets the marshaller of closure. The marshal_data provides a way for a meta marshaller to provide additional information to the marshaller. (See g_closure_set_meta_marshal().) For GObject's C predefined marshallers (the g_cclosure_marshal_*() functions), what it provides is a callback function to use instead of closure->callback.

g_closure_add_marshal_guards ()

void        g_closure_add_marshal_guards    (GClosure *closure,
                                             gpointer pre_marshal_data,
                                             GClosureNotify pre_marshal_notify,
                                             gpointer post_marshal_data,
                                             GClosureNotify post_marshal_notify);

Adds a pair of notifiers which get invoked before and after the closure callback, respectively. This is typically used to protect the extra arguments for the duration of the callback. See g_object_watch_closure() for an example of marshal guards.

g_closure_set_meta_marshal ()

void        g_closure_set_meta_marshal      (GClosure *closure,
                                             gpointer marshal_data,
                                             GClosureMarshal meta_marshal);

Sets the meta marshaller of closure. A meta marshaller wraps closure->marshal and modifies the way it is called in some fashion. The most common use of this facility is for C callbacks. The same marshallers (generated by glib-genmarshal) are used everywhere, but the way that we get the callback function differs. In most cases we want to use closure->callback, but in other cases we want to use use some different technique to retrieve the callbakc function.

For example, class closures for signals (see g_signal_type_cclosure_new()) retrieve the callback function from a fixed offset in the class structure. The meta marshaller retrieves the right callback and passes it to the marshaller as the marshal_data argument.

g_source_set_closure ()

void        g_source_set_closure            (GSource *source,
                                             GClosure *closure);

Set the callback for a source as a GClosure.

If the source is not one of the standard GLib types, the closure_callback and closure_marshal fields of the GSourceFuncs structure must have been filled in with pointers to appropriate functions.

G_TYPE_IO_CHANNEL

#define G_TYPE_IO_CHANNEL (g_io_channel_get_type ())

The GType for GIOChannel.

G_TYPE_IO_CONDITION

#define G_TYPE_IO_CONDITION (g_io_condition_get_type ())

The GType for GIOCondition.

g_cclosure_marshal_VOID__VOID ()

void        g_cclosure_marshal_VOID__VOID   (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, gpointer user_data).

g_cclosure_marshal_VOID__BOOLEAN ()

void        g_cclosure_marshal_VOID__BOOLEAN
                                            (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, gboolean arg1, gpointer user_data).

g_cclosure_marshal_VOID__CHAR ()

void        g_cclosure_marshal_VOID__CHAR   (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, gchar arg1, gpointer user_data).

g_cclosure_marshal_VOID__UCHAR ()

void        g_cclosure_marshal_VOID__UCHAR  (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, guchar arg1, gpointer user_data).

g_cclosure_marshal_VOID__INT ()

void        g_cclosure_marshal_VOID__INT    (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, gint arg1, gpointer user_data).

g_cclosure_marshal_VOID__UINT ()

void        g_cclosure_marshal_VOID__UINT   (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, guint arg1, gpointer user_data).

g_cclosure_marshal_VOID__LONG ()

void        g_cclosure_marshal_VOID__LONG   (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, glong arg1, gpointer user_data).

g_cclosure_marshal_VOID__ULONG ()

void        g_cclosure_marshal_VOID__ULONG  (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, gulong arg1, gpointer user_data).

g_cclosure_marshal_VOID__ENUM ()

void        g_cclosure_marshal_VOID__ENUM   (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, gint arg1, gpointer user_data) where the gint parameter denotes an enumeration type..

g_cclosure_marshal_VOID__FLAGS ()

void        g_cclosure_marshal_VOID__FLAGS  (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, gint arg1, gpointer user_data) where the gint parameter denotes a flags type denotes a flags type.

g_cclosure_marshal_VOID__FLOAT ()

void        g_cclosure_marshal_VOID__FLOAT  (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, gfloat arg1, gpointer user_data).

g_cclosure_marshal_VOID__DOUBLE ()

void        g_cclosure_marshal_VOID__DOUBLE (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, gdouble arg1, gpointer user_data).

g_cclosure_marshal_VOID__STRING ()

void        g_cclosure_marshal_VOID__STRING (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, const gchar *arg1, gpointer user_data).

g_cclosure_marshal_VOID__PARAM ()

void        g_cclosure_marshal_VOID__PARAM  (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, GParamSpec *arg1, gpointer user_data).

g_cclosure_marshal_VOID__BOXED ()

void        g_cclosure_marshal_VOID__BOXED  (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, GBoxed *arg1, gpointer user_data).

g_cclosure_marshal_VOID__POINTER ()

void        g_cclosure_marshal_VOID__POINTER
                                            (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, gpointer arg1, gpointer user_data).

g_cclosure_marshal_VOID__OBJECT ()

void        g_cclosure_marshal_VOID__OBJECT (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, GOBject *arg1, gpointer user_data).

g_cclosure_marshal_STRING__OBJECT_POINTER ()

void        g_cclosure_marshal_STRING__OBJECT_POINTER
                                            (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, GObject *arg1, gpointer arg2, gpointer user_data).

g_cclosure_marshal_VOID__UINT_POINTER ()

void        g_cclosure_marshal_VOID__UINT_POINTER
                                            (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type void (*callback) (gpointer instance, guint arg1, gpointer arg2, gpointer user_data).

g_cclosure_marshal_BOOLEAN__FLAGS ()

void        g_cclosure_marshal_BOOLEAN__FLAGS
                                            (GClosure *closure,
                                             GValue *return_value,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer invocation_hint,
                                             gpointer marshal_data);

A marshaller for a GCClosure with a callback of type gboolean (*callback) (gpointer instance, gint arg1, gpointer user_data) where the gint parameter denotes a flags type.

g_cclosure_marshal_BOOL__FLAGS

#define     g_cclosure_marshal_BOOL__FLAGS

Another name for g_cclosure_marshal_BOOLEAN__FLAGS().