/* GObject - GLib Type, Object, Parameter and Signal Library

  * Copyright (C) 2000-2001 Red Hat, Inc.

  * Copyright (C) 2005 Imendio AB

  * Portions copyright (c) 2006-2009 Nokia Corporation.  All rights reserved.

  *

  * This library is free software; you can redistribute it and/or

  * modify it under the terms of the GNU Lesser General Public

  * License as published by the Free Software Foundation; either

  * version 2 of the License, or (at your option) any later version.

  *

  * This library is distributed in the hope that it will be useful,

  * but WITHOUT ANY WARRANTY; without even the implied warranty of

  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

  * Lesser General Public License for more details.

  *

  * You should have received a copy of the GNU Lesser General

  * Public License along with this library; if not, write to the

  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,

  * Boston, MA 02111-1307, USA.

  */

 #if !defined (__GLIB_GOBJECT_H_INSIDE__) && !defined (GOBJECT_COMPILATION)

 #error "Only <glib-object.h> can be included directly."

 #endif

 #ifndef __G_CLOSURE_H__

 #define __G_CLOSURE_H__

 #include        <gobject/gtype.h>

 G_BEGIN_DECLS

 /* --- defines --- */

 /**

  * G_CLOSURE_NEEDS_MARSHAL:

  * @closure: a #GClosure

  * 

  * Check if the closure still needs a marshaller. See g_closure_set_marshal().

  *

  * Returns: %TRUE if a #GClosureMarshal marshaller has not yet been set on 

  * @closure.

  */

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

 /**

  * G_CLOSURE_N_NOTIFIERS:

  * @cl: a #GClosure

  * 

  * Get 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().

  *

  * Returns: number of notifiers

  */

 #define	G_CLOSURE_N_NOTIFIERS(cl)	 ((cl)->meta_marshal + ((cl)->n_guards << 1L) + \

                                           (cl)->n_fnotifiers + (cl)->n_inotifiers)

 /**

  * G_CCLOSURE_SWAP_DATA:

  * @cclosure: a #GCClosure

  * 

  * Checks whether the user data of the #GCClosure should be passed as the

  * first parameter to the callback. See g_cclosure_new_swap().

  *

  * Returns: %TRUE if data has to be swapped.

  */

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

 /**

  * G_CALLBACK:

  * @f: a function pointer.

  * 

  * Cast a function pointer to a #GCallback.

  */

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

 /* -- typedefs --- */

 typedef struct _GClosure		 GClosure;

 typedef struct _GClosureNotifyData	 GClosureNotifyData;

 /**

  * GCallback:

  * 

  * 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. 

  */

 typedef void  (*GCallback)              (void);

 /**

  * GClosureNotify:

  * @data: data specified when registering the notification callback

  * @closure: the #GClosure on which the notification is emitted

  * 

  * The type used for the various notification callbacks which can be registered

  * on closures.

  */

 typedef void  (*GClosureNotify)		(gpointer	 data,

 					 GClosure	*closure);

 /**

  * GClosureMarshal:

  * @closure: the #GClosure to which the marshaller belongs

  * @return_value: a #GValue to store the return value. May be %NULL if the

  *  callback of @closure doesn't return a value.

  * @n_param_values: the length of the @param_values array

  * @param_values: an array of #GValue<!-- -->s holding the arguments on

  *  which to invoke the callback of @closure

  * @invocation_hint: the invocation hint given as the last argument

  *  to g_closure_invoke()

  * @marshal_data: additional data specified when registering the marshaller,

  *  see g_closure_set_marshal() and g_closure_set_meta_marshal()

  * 

  * The type used for marshaller functions.

  */

 typedef void  (*GClosureMarshal)	(GClosure	*closure,

 					 GValue         *return_value,

 					 guint           n_param_values,

 					 const GValue   *param_values,

 					 gpointer        invocation_hint,

 					 gpointer	 marshal_data);

 /**

  * GCClosure:

  * @closure: the #GClosure

  * @callback: the callback function

  * 

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

  */

 typedef struct _GCClosure		 GCClosure;

 /* --- structures --- */

 struct _GClosureNotifyData

 {

   gpointer       data;

   GClosureNotify notify;

 };

 /**

  * GClosure:

  * @in_marshal: Indicates whether the closure is currently being invoked with 

  *  g_closure_invoke()

  * @is_invalid: Indicates whether the closure has been invalidated by 

  *  g_closure_invalidate()

  * 

  * A #GClosure represents a callback supplied by the programmer.

  */

 struct _GClosure

 {

   /*< private >*/

   volatile      	guint	 ref_count : 15;

   volatile       	guint	 meta_marshal : 1;

   volatile       	guint	 n_guards : 1;

   volatile       	guint	 n_fnotifiers : 2;	/* finalization notifiers */

   volatile       	guint	 n_inotifiers : 8;	/* invalidation notifiers */

   volatile       	guint	 in_inotify : 1;

   volatile       	guint	 floating : 1;

   /*< protected >*/

   volatile         	guint	 derivative_flag : 1;

   /*< public >*/

   volatile       	guint	 in_marshal : 1;

   volatile       	guint	 is_invalid : 1;

   /*< private >*/	void   (*marshal)  (GClosure       *closure,

 					    GValue /*out*/ *return_value,

 					    guint           n_param_values,

 					    const GValue   *param_values,

 					    gpointer        invocation_hint,

 					    gpointer	    marshal_data);

   /*< protected >*/	gpointer data;

   /*< private >*/	GClosureNotifyData *notifiers;

   /* invariants/constrains:

    * - ->marshal and ->data are _invalid_ as soon as ->is_invalid==TRUE

    * - invocation of all inotifiers occours prior to fnotifiers

    * - order of inotifiers is random

    *   inotifiers may _not_ free/invalidate parameter values (e.g. ->data)

    * - order of fnotifiers is random

    * - each notifier may only be removed before or during its invocation

    * - reference counting may only happen prior to fnotify invocation

    *   (in that sense, fnotifiers are really finalization handlers)

    */

 };

 /* closure for C function calls, callback() is the user function

  */

 struct _GCClosure

 {

   GClosure	closure;

   gpointer	callback;

 };

 /* --- prototypes --- */

 IMPORT_C GClosure* g_cclosure_new			(GCallback	callback_func,

 						 gpointer	user_data,

 						 GClosureNotify destroy_data);

 IMPORT_C GClosure* g_cclosure_new_swap			(GCallback	callback_func,

 						 gpointer	user_data,

 						 GClosureNotify destroy_data);

 IMPORT_C GClosure* g_signal_type_cclosure_new		(GType          itype,

 						 guint          struct_offset);

 /* --- prototypes --- */

 IMPORT_C GClosure* g_closure_ref				(GClosure	*closure);

 IMPORT_C void	  g_closure_sink			(GClosure	*closure);

 IMPORT_C void	  g_closure_unref			(GClosure	*closure);

 /* intimidating */

 IMPORT_C GClosure* g_closure_new_simple			(guint		 sizeof_closure,

 						 gpointer	 data);

 IMPORT_C void	  g_closure_add_finalize_notifier	(GClosure       *closure,

 						 gpointer	 notify_data,

 						 GClosureNotify	 notify_func);

 IMPORT_C void	  g_closure_remove_finalize_notifier	(GClosure       *closure,

 						 gpointer	 notify_data,

 						 GClosureNotify	 notify_func);

 IMPORT_C void	  g_closure_add_invalidate_notifier	(GClosure       *closure,

 						 gpointer	 notify_data,

 						 GClosureNotify	 notify_func);

 IMPORT_C void	  g_closure_remove_invalidate_notifier	(GClosure       *closure,

 						 gpointer	 notify_data,

 						 GClosureNotify	 notify_func);

 IMPORT_C void	  g_closure_add_marshal_guards		(GClosure	*closure,

 						 gpointer        pre_marshal_data,

 						 GClosureNotify	 pre_marshal_notify,

 						 gpointer        post_marshal_data,

 						 GClosureNotify	 post_marshal_notify);

 IMPORT_C void	  g_closure_set_marshal			(GClosure	*closure,

 						 GClosureMarshal marshal);

 IMPORT_C void	  g_closure_set_meta_marshal		(GClosure       *closure,

 						 gpointer	 marshal_data,

 						 GClosureMarshal meta_marshal);

 IMPORT_C void	  g_closure_invalidate			(GClosure	*closure);

 IMPORT_C void	  g_closure_invoke			(GClosure 	*closure,

 						 GValue	/*out*/	*return_value,

 						 guint		 n_param_values,

 						 const GValue	*param_values,

 						 gpointer	 invocation_hint);

 /* FIXME:

    OK:  data_object::destroy		-> closure_invalidate();

    MIS:	closure_invalidate()		-> disconnect(closure);

    MIS:	disconnect(closure)		-> (unlink) closure_unref();

    OK:	closure_finalize()		-> g_free (data_string);

    random remarks:

    - need marshaller repo with decent aliasing to base types

    - provide marshaller collection, virtually covering anything out there

 */

 G_END_DECLS

 #endif /* __G_CLOSURE_H__ */