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

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

 * Copyright (C) 2005 Imendio AB

 *

 * 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 2.1 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, see <http://www.gnu.org/licenses/>.

 */

#ifndef __G_CLOSURE_H__

#define __G_CLOSURE_H__

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

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

#endif

#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)->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: (nullable): 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: (array length=n_param_values): an array of

 *  #GValues holding the arguments on which to invoke the

 *  callback of @closure

 * @invocation_hint: (nullable): the invocation hint given as the

 *  last argument to g_closure_invoke()

 * @marshal_data: (nullable): 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);

/**

 * GVaClosureMarshal:

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

 * @return_value: (nullable): a #GValue to store the return

 *  value. May be %NULL if the callback of @closure doesn't return a

 *  value.

 * @instance: (type GObject.TypeInstance): the instance on which the closure is

 *  invoked.

 * @args: va_list of arguments to be passed to the closure.

 * @marshal_data: (nullable): additional data specified when

 *  registering the marshaller, see g_closure_set_marshal() and

 *  g_closure_set_meta_marshal()

 * @n_params: the length of the @param_types array

 * @param_types: (array length=n_params): the #GType of each argument from

 *  @args.

 *

 * This is the signature of va_list marshaller functions, an optional

 * marshaller that can be used in some situations to avoid

 * marshalling the signal argument into GValues.

 */

typedef void (* GVaClosureMarshal) (GClosure *closure,

				    GValue   *return_value,

				    gpointer  instance,

				    va_list   args,

				    gpointer  marshal_data,

				    int       n_params,

				    GType    *param_types);

/**

 * 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;

  /* meta_marshal is not used anymore but must be zero for historical reasons

     as it was exposed in the G_CLOSURE_N_NOTIFIERS macro */

  volatile       	guint	 meta_marshal_nouse : 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 --- */

GLIB_AVAILABLE_IN_ALL

GClosure* g_cclosure_new			(GCallback	callback_func,

						 gpointer	user_data,

						 GClosureNotify destroy_data);

GLIB_AVAILABLE_IN_ALL

GClosure* g_cclosure_new_swap			(GCallback	callback_func,

						 gpointer	user_data,

						 GClosureNotify destroy_data);

GLIB_AVAILABLE_IN_ALL

GClosure* g_signal_type_cclosure_new		(GType          itype,

						 guint          struct_offset);

/* --- prototypes --- */

GLIB_AVAILABLE_IN_ALL

GClosure* g_closure_ref				(GClosure	*closure);

GLIB_AVAILABLE_IN_ALL

void	  g_closure_sink			(GClosure	*closure);

GLIB_AVAILABLE_IN_ALL

void	  g_closure_unref			(GClosure	*closure);

/* intimidating */

GLIB_AVAILABLE_IN_ALL

GClosure* g_closure_new_simple			(guint		 sizeof_closure,

						 gpointer	 data);

GLIB_AVAILABLE_IN_ALL

void	  g_closure_add_finalize_notifier	(GClosure       *closure,

						 gpointer	 notify_data,

						 GClosureNotify	 notify_func);

GLIB_AVAILABLE_IN_ALL

void	  g_closure_remove_finalize_notifier	(GClosure       *closure,

						 gpointer	 notify_data,

						 GClosureNotify	 notify_func);

GLIB_AVAILABLE_IN_ALL

void	  g_closure_add_invalidate_notifier	(GClosure       *closure,

						 gpointer	 notify_data,

						 GClosureNotify	 notify_func);

GLIB_AVAILABLE_IN_ALL

void	  g_closure_remove_invalidate_notifier	(GClosure       *closure,

						 gpointer	 notify_data,

						 GClosureNotify	 notify_func);

GLIB_AVAILABLE_IN_ALL

void	  g_closure_add_marshal_guards		(GClosure	*closure,

						 gpointer        pre_marshal_data,

						 GClosureNotify	 pre_marshal_notify,

						 gpointer        post_marshal_data,

						 GClosureNotify	 post_marshal_notify);

GLIB_AVAILABLE_IN_ALL

void	  g_closure_set_marshal			(GClosure	*closure,

						 GClosureMarshal marshal);

GLIB_AVAILABLE_IN_ALL

void	  g_closure_set_meta_marshal		(GClosure       *closure,

						 gpointer	 marshal_data,

						 GClosureMarshal meta_marshal);

GLIB_AVAILABLE_IN_ALL

void	  g_closure_invalidate			(GClosure	*closure);

GLIB_AVAILABLE_IN_ALL

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

*/

GLIB_AVAILABLE_IN_ALL

void g_cclosure_marshal_generic (GClosure     *closure,

                                 GValue       *return_gvalue,

                                 guint         n_param_values,

                                 const GValue *param_values,

                                 gpointer      invocation_hint,

                                 gpointer      marshal_data);

GLIB_AVAILABLE_IN_ALL

void g_cclosure_marshal_generic_va (GClosure *closure,

				    GValue   *return_value,

				    gpointer  instance,

				    va_list   args_list,

				    gpointer  marshal_data,

				    int       n_params,

				    GType    *param_types);

G_END_DECLS

#endif /* __G_CLOSURE_H__ */