/* GObject - GLib Type, Object, Parameter and Signal Library
 * Copyright (C) 2000 Red Hat, Inc.
 *
 * 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.
 */
#ifndef __G_CLOSURE_H__
#define __G_CLOSURE_H__


#include        <gobject/gtype.h>


#ifdef __cplusplus
extern "C" {
#endif /* __cplusplus */



/* --- defines --- */
#define	G_CLOSURE_NEEDS_MARSHAL(closure) (((GClosure*) (closure))->marshal == NULL)
#define	G_CCLOSURE_SWAP_DATA(cclosure)	 (((GClosure*) (closure))->derivative_flag)
#define	G_CALLBACK(f)			 ((GCallback) (f))


/* -- typedefs --- */
typedef struct _GClosure		 GClosure;
typedef struct _GClosureNotifyData	 GClosureNotifyData;
typedef	gpointer GCallback;
typedef void  (*GClosureNotify)		(gpointer	 data,
					 GClosure	*closure);
typedef void  (*GClosureMarshal)	(GClosure	*closure,
					 GValue         *return_value,
					 guint           n_param_values,
					 const GValue   *param_values,
					 gpointer        invocation_hint,
					 gpointer	 marshal_data);
typedef struct _GCClosure		 GCClosure;


/* --- structures --- */
struct _GClosureNotifyData
{
  gpointer       data;
  GClosureNotify notify;
};
struct _GClosure
{
  /*< private >*/	guint	 ref_count : 15;
  /*< private >*/	guint	 meta_marshal : 1;
  /*< private >*/	guint	 n_guards : 1;
  /*< private >*/	guint	 n_fnotifiers : 2;	/* finalization notifiers */
  /*< private >*/	guint	 n_inotifiers : 8;	/* invalidation notifiers */
  /*< private >*/	guint	 in_inotify : 1;
  /*< private >*/	guint	 floating : 1;
  /*< protected >*/	guint	 derivative_flag : 1;
  /*< puplic >*/	guint	 in_marshal : 1;
  /*< public >*/	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
   * - notifiers may only be removed before or during their 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 --- */
GClosure*	g_cclosure_new			(GCallback	callback_func,
						 gpointer	user_data,
						 GClosureNotify destroy_data);
GClosure*	g_cclosure_new_swap		(GCallback	callback_func,
						 gpointer	user_data,
						 GClosureNotify destroy_data);
GClosure*	g_signal_type_cclosure_new	(GType          itype,
						 guint          struct_offset);


/* --- prototypes --- */
GClosure*	g_closure_ref			(GClosure	*closure);
void		g_closure_unref			(GClosure	*closure);
/* intimidating */
GClosure*	g_closure_new_simple		(guint		 sizeof_closure,
						 gpointer	 data);
void		g_closure_add_fnotify		(GClosure       *closure,
						 gpointer	 notify_data,
						 GClosureNotify	 notify_func);
void		g_closure_remove_fnotify	(GClosure       *closure,
						 gpointer	 notify_data,
						 GClosureNotify	 notify_func);
void		g_closure_add_inotify		(GClosure       *closure,
						 gpointer	 notify_data,
						 GClosureNotify	 notify_func);
void		g_closure_remove_inotify	(GClosure       *closure,
						 gpointer	 notify_data,
						 GClosureNotify	 notify_func);
void		g_closure_add_marshal_guards	(GClosure	*closure,
						 gpointer        pre_marshal_data,
						 GClosureNotify	 pre_marshal_notify,
						 gpointer        post_marshal_data,
						 GClosureNotify	 post_marshal_notify);
void		g_closure_set_marshal		(GClosure	*closure,
						 GClosureMarshal marshal);
void		g_closure_set_meta_marshal	(GClosure       *closure,
						 gpointer	 marshal_data,
						 GClosureMarshal meta_marshal);
void		g_closure_invalidate		(GClosure	*closure);
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
*/


#ifdef __cplusplus
}
#endif /* __cplusplus */

#endif /* __G_CLOSURE_H__ */