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

 * Copyright (C) 2000-2001 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 2.1 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_SIGNAL_H__

#define __G_SIGNAL_H__

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

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

#endif

#include	<gobject/gclosure.h>

#include	<gobject/gvalue.h>

#include	<gobject/gparam.h>

#include	<gobject/gmarshal.h>

G_BEGIN_DECLS

/* --- typedefs --- */

typedef struct _GSignalQuery		 GSignalQuery;

typedef struct _GSignalInvocationHint	 GSignalInvocationHint;

/**

 * GSignalCMarshaller:

 * 

 * This is the signature of marshaller functions, required to marshall

 * arrays of parameter values to signal emissions into C language callback

 * invocations. It is merely an alias to #GClosureMarshal since the #GClosure

 * mechanism takes over responsibility of actual function invocation for the

 * signal system.

 */

typedef GClosureMarshal			 GSignalCMarshaller;

/**

 * GSignalCVaMarshaller:

 * 

 * 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 GVaClosureMarshal		 GSignalCVaMarshaller;

/**

 * GSignalEmissionHook:

 * @ihint: Signal invocation hint, see #GSignalInvocationHint.

 * @n_param_values: the number of parameters to the function, including

 *  the instance on which the signal was emitted.

 * @param_values: (array length=n_param_values): the instance on which

 *  the signal was emitted, followed by the parameters of the emission.

 * @data: user data associated with the hook.

 * 

 * A simple function pointer to get invoked when the signal is emitted. This 

 * allows you to tie a hook to the signal type, so that it will trap all 

 * emissions of that signal, from any object.

 * 

 * You may not attach these to signals created with the #G_SIGNAL_NO_HOOKS flag.

 * 

 * Returns: whether it wants to stay connected. If it returns %FALSE, the signal 

 *  hook is disconnected (and destroyed).

 */

typedef gboolean (*GSignalEmissionHook) (GSignalInvocationHint *ihint,

					 guint			n_param_values,

					 const GValue	       *param_values,

					 gpointer		data);

/**

 * GSignalAccumulator:

 * @ihint: Signal invocation hint, see #GSignalInvocationHint.

 * @return_accu: Accumulator to collect callback return values in, this

 *  is the return value of the current signal emission.

 * @handler_return: A #GValue holding the return value of the signal handler.

 * @data: Callback data that was specified when creating the signal.

 * 

 * The signal accumulator is a special callback function that can be used

 * to collect return values of the various callbacks that are called

 * during a signal emission. The signal accumulator is specified at signal

 * creation time, if it is left %NULL, no accumulation of callback return

 * values is performed. The return value of signal emissions is then the

 * value returned by the last callback.

 * 

 * Returns: The accumulator function returns whether the signal emission

 *  should be aborted. Returning %FALSE means to abort the

 *  current emission and %TRUE is returned for continuation.

 */

typedef gboolean (*GSignalAccumulator)	(GSignalInvocationHint *ihint,

					 GValue		       *return_accu,

					 const GValue	       *handler_return,

					 gpointer               data);

/* --- run, match and connect types --- */

/**

 * GSignalFlags:

 * @G_SIGNAL_RUN_FIRST: Invoke the object method handler in the first emission stage.

 * @G_SIGNAL_RUN_LAST: Invoke the object method handler in the third emission stage.

 * @G_SIGNAL_RUN_CLEANUP: Invoke the object method handler in the last emission stage.

 * @G_SIGNAL_NO_RECURSE: Signals being emitted for an object while currently being in

 *  emission for this very object will not be emitted recursively,

 *  but instead cause the first emission to be restarted.

 * @G_SIGNAL_DETAILED: This signal supports "::detail" appendices to the signal name

 *  upon handler connections and emissions.

 * @G_SIGNAL_ACTION: Action signals are signals that may freely be emitted on alive

 *  objects from user code via g_signal_emit() and friends, without

 *  the need of being embedded into extra code that performs pre or

 *  post emission adjustments on the object. They can also be thought

 *  of as object methods which can be called generically by 

 *  third-party code.

 * @G_SIGNAL_NO_HOOKS: No emissions hooks are supported for this signal.

 * @G_SIGNAL_MUST_COLLECT: Varargs signal emission will always collect the

 *   arguments, even if there are no signal handlers connected.  Since 2.30.

 * @G_SIGNAL_DEPRECATED: The signal is deprecated and will be removed

 *   in a future version. A warning will be generated if it is connected while

 *   running with G_ENABLE_DIAGNOSTIC=1.  Since 2.32.

 * 

 * The signal flags are used to specify a signal's behaviour, the overall

 * signal description outlines how especially the RUN flags control the

 * stages of a signal emission.

 */

typedef enum

{

  G_SIGNAL_RUN_FIRST	= 1 << 0,

  G_SIGNAL_RUN_LAST	= 1 << 1,

  G_SIGNAL_RUN_CLEANUP	= 1 << 2,

  G_SIGNAL_NO_RECURSE	= 1 << 3,

  G_SIGNAL_DETAILED	= 1 << 4,

  G_SIGNAL_ACTION	= 1 << 5,

  G_SIGNAL_NO_HOOKS	= 1 << 6,

  G_SIGNAL_MUST_COLLECT = 1 << 7,

  G_SIGNAL_DEPRECATED   = 1 << 8

} GSignalFlags;

/**

 * G_SIGNAL_FLAGS_MASK:

 * 

 * A mask for all #GSignalFlags bits.

 */

#define G_SIGNAL_FLAGS_MASK  0x1ff

/**

 * GConnectFlags:

 * @G_CONNECT_AFTER: whether the handler should be called before or after the 

 *  default handler of the signal.

 * @G_CONNECT_SWAPPED: whether the instance and data should be swapped when

 *  calling the handler; see g_signal_connect_swapped() for an example.

 * 

 * The connection flags are used to specify the behaviour of a signal's 

 * connection.

 */

typedef enum

{

  G_CONNECT_AFTER	= 1 << 0,

  G_CONNECT_SWAPPED	= 1 << 1

} GConnectFlags;

/**

 * GSignalMatchType:

 * @G_SIGNAL_MATCH_ID: The signal id must be equal.

 * @G_SIGNAL_MATCH_DETAIL: The signal detail be equal.

 * @G_SIGNAL_MATCH_CLOSURE: The closure must be the same.

 * @G_SIGNAL_MATCH_FUNC: The C closure callback must be the same.

 * @G_SIGNAL_MATCH_DATA: The closure data must be the same.

 * @G_SIGNAL_MATCH_UNBLOCKED: Only unblocked signals may matched.

 * 

 * The match types specify what g_signal_handlers_block_matched(),

 * g_signal_handlers_unblock_matched() and g_signal_handlers_disconnect_matched()

 * match signals by.

 */

typedef enum

{

  G_SIGNAL_MATCH_ID	   = 1 << 0,

  G_SIGNAL_MATCH_DETAIL	   = 1 << 1,

  G_SIGNAL_MATCH_CLOSURE   = 1 << 2,

  G_SIGNAL_MATCH_FUNC	   = 1 << 3,

  G_SIGNAL_MATCH_DATA	   = 1 << 4,

  G_SIGNAL_MATCH_UNBLOCKED = 1 << 5

} GSignalMatchType;

/**

 * G_SIGNAL_MATCH_MASK:

 * 

 * A mask for all #GSignalMatchType bits.

 */

#define G_SIGNAL_MATCH_MASK  0x3f

/**

 * G_SIGNAL_TYPE_STATIC_SCOPE:

 * 

 * This macro flags signal argument types for which the signal system may 

 * assume that instances thereof remain persistent across all signal emissions

 * they are used in. This is only useful for non ref-counted, value-copy types.

 * 

 * To flag a signal argument in this way, add `| G_SIGNAL_TYPE_STATIC_SCOPE`

 * to the corresponding argument of g_signal_new().

 * |[

 * g_signal_new ("size_request",

 *   G_TYPE_FROM_CLASS (gobject_class),

 * 	 G_SIGNAL_RUN_FIRST,

 * 	 G_STRUCT_OFFSET (GtkWidgetClass, size_request),

 * 	 NULL, NULL,

 * 	 _gtk_marshal_VOID__BOXED,

 * 	 G_TYPE_NONE, 1,

 * 	 GTK_TYPE_REQUISITION | G_SIGNAL_TYPE_STATIC_SCOPE);

 * ]|

 */

#define	G_SIGNAL_TYPE_STATIC_SCOPE (G_TYPE_FLAG_RESERVED_ID_BIT)

/* --- signal information --- */

/**

 * GSignalInvocationHint:

 * @signal_id: The signal id of the signal invoking the callback

 * @detail: The detail passed on for this emission

 * @run_type: The stage the signal emission is currently in, this

 *  field will contain one of %G_SIGNAL_RUN_FIRST,

 *  %G_SIGNAL_RUN_LAST or %G_SIGNAL_RUN_CLEANUP.

 * 

 * The #GSignalInvocationHint structure is used to pass on additional information

 * to callbacks during a signal emission.

 */

struct _GSignalInvocationHint

{

  guint		signal_id;

  GQuark	detail;

  GSignalFlags	run_type;

};

/**

 * GSignalQuery:

 * @signal_id: The signal id of the signal being queried, or 0 if the

 *  signal to be queried was unknown.

 * @signal_name: The signal name.

 * @itype: The interface/instance type that this signal can be emitted for.

 * @signal_flags: The signal flags as passed in to g_signal_new().

 * @return_type: The return type for user callbacks.

 * @n_params: The number of parameters that user callbacks take.

 * @param_types: (array length=n_params): The individual parameter types for

 *  user callbacks, note that the effective callback signature is:

 *  |[

 *  @return_type callback (#gpointer     data1,

 *  [param_types param_names,]

 *  gpointer     data2);

 *  ]|

 * 

 * A structure holding in-depth information for a specific signal. It is

 * filled in by the g_signal_query() function.

 */

struct _GSignalQuery

{

  guint		signal_id;

  const gchar  *signal_name;

  GType		itype;

  GSignalFlags	signal_flags;

  GType		return_type; /* mangled with G_SIGNAL_TYPE_STATIC_SCOPE flag */

  guint		n_params;

  const GType  *param_types; /* mangled with G_SIGNAL_TYPE_STATIC_SCOPE flag */

};

/* --- signals --- */

GLIB_AVAILABLE_IN_ALL

guint                 g_signal_newv         (const gchar        *signal_name,

					     GType               itype,

					     GSignalFlags        signal_flags,

					     GClosure           *class_closure,

					     GSignalAccumulator	 accumulator,

					     gpointer		 accu_data,

					     GSignalCMarshaller  c_marshaller,

					     GType               return_type,

					     guint               n_params,

					     GType              *param_types);

GLIB_AVAILABLE_IN_ALL

guint                 g_signal_new_valist   (const gchar        *signal_name,

					     GType               itype,

					     GSignalFlags        signal_flags,

					     GClosure           *class_closure,

					     GSignalAccumulator	 accumulator,

					     gpointer		 accu_data,

					     GSignalCMarshaller  c_marshaller,

					     GType               return_type,

					     guint               n_params,

					     va_list             args);

GLIB_AVAILABLE_IN_ALL

guint                 g_signal_new          (const gchar        *signal_name,

					     GType               itype,

					     GSignalFlags        signal_flags,

					     guint               class_offset,

					     GSignalAccumulator	 accumulator,

					     gpointer		 accu_data,

					     GSignalCMarshaller  c_marshaller,

					     GType               return_type,

					     guint               n_params,

					     ...);

GLIB_AVAILABLE_IN_ALL

guint            g_signal_new_class_handler (const gchar        *signal_name,

                                             GType               itype,

                                             GSignalFlags        signal_flags,

                                             GCallback           class_handler,

                                             GSignalAccumulator  accumulator,

                                             gpointer            accu_data,

                                             GSignalCMarshaller  c_marshaller,

                                             GType               return_type,

                                             guint               n_params,

                                             ...);

GLIB_AVAILABLE_IN_ALL

void             g_signal_set_va_marshaller (guint              signal_id,

					     GType              instance_type,

					     GSignalCVaMarshaller va_marshaller);

GLIB_AVAILABLE_IN_ALL

void                  g_signal_emitv        (const GValue       *instance_and_params,

					     guint               signal_id,

					     GQuark              detail,

					     GValue             *return_value);

GLIB_AVAILABLE_IN_ALL

void                  g_signal_emit_valist  (gpointer            instance,

					     guint               signal_id,

					     GQuark              detail,

					     va_list             var_args);

GLIB_AVAILABLE_IN_ALL

void                  g_signal_emit         (gpointer            instance,

					     guint               signal_id,

					     GQuark              detail,

					     ...);

GLIB_AVAILABLE_IN_ALL

void                  g_signal_emit_by_name (gpointer            instance,

					     const gchar        *detailed_signal,

					     ...);

GLIB_AVAILABLE_IN_ALL

guint                 g_signal_lookup       (const gchar        *name,

					     GType               itype);

GLIB_AVAILABLE_IN_ALL

const gchar *         g_signal_name         (guint               signal_id);

GLIB_AVAILABLE_IN_ALL

void                  g_signal_query        (guint               signal_id,

					     GSignalQuery       *query);

GLIB_AVAILABLE_IN_ALL

guint*                g_signal_list_ids     (GType               itype,

					     guint              *n_ids);

GLIB_AVAILABLE_IN_ALL

gboolean	      g_signal_parse_name   (const gchar	*detailed_signal,

					     GType		 itype,

					     guint		*signal_id_p,

					     GQuark		*detail_p,

					     gboolean		 force_detail_quark);

GLIB_AVAILABLE_IN_ALL

GSignalInvocationHint* g_signal_get_invocation_hint (gpointer    instance);

/* --- signal emissions --- */

GLIB_AVAILABLE_IN_ALL

void	g_signal_stop_emission		    (gpointer		  instance,

					     guint		  signal_id,

					     GQuark		  detail);

GLIB_AVAILABLE_IN_ALL

void	g_signal_stop_emission_by_name	    (gpointer		  instance,

					     const gchar	 *detailed_signal);

GLIB_AVAILABLE_IN_ALL

gulong	g_signal_add_emission_hook	    (guint		  signal_id,

					     GQuark		  detail,

					     GSignalEmissionHook  hook_func,

					     gpointer	       	  hook_data,

					     GDestroyNotify	  data_destroy);

GLIB_AVAILABLE_IN_ALL

void	g_signal_remove_emission_hook	    (guint		  signal_id,

					     gulong		  hook_id);

/* --- signal handlers --- */

GLIB_AVAILABLE_IN_ALL

gboolean g_signal_has_handler_pending	      (gpointer		  instance,

					       guint		  signal_id,

					       GQuark		  detail,

					       gboolean		  may_be_blocked);

GLIB_AVAILABLE_IN_ALL

gulong	 g_signal_connect_closure_by_id	      (gpointer		  instance,

					       guint		  signal_id,

					       GQuark		  detail,

					       GClosure		 *closure,

					       gboolean		  after);

GLIB_AVAILABLE_IN_ALL

gulong	 g_signal_connect_closure	      (gpointer		  instance,

					       const gchar       *detailed_signal,

					       GClosure		 *closure,

					       gboolean		  after);

GLIB_AVAILABLE_IN_ALL

gulong	 g_signal_connect_data		      (gpointer		  instance,

					       const gchar	 *detailed_signal,

					       GCallback	  c_handler,

					       gpointer		  data,

					       GClosureNotify	  destroy_data,

					       GConnectFlags	  connect_flags);

GLIB_AVAILABLE_IN_ALL

void	 g_signal_handler_block		      (gpointer		  instance,

					       gulong		  handler_id);

GLIB_AVAILABLE_IN_ALL

void	 g_signal_handler_unblock	      (gpointer		  instance,

					       gulong		  handler_id);

GLIB_AVAILABLE_IN_ALL

void	 g_signal_handler_disconnect	      (gpointer		  instance,

					       gulong		  handler_id);

GLIB_AVAILABLE_IN_ALL

gboolean g_signal_handler_is_connected	      (gpointer		  instance,

					       gulong		  handler_id);

GLIB_AVAILABLE_IN_ALL

gulong	 g_signal_handler_find		      (gpointer		  instance,

					       GSignalMatchType	  mask,

					       guint		  signal_id,

					       GQuark		  detail,

					       GClosure		 *closure,

					       gpointer		  func,

					       gpointer		  data);

GLIB_AVAILABLE_IN_ALL

guint	 g_signal_handlers_block_matched      (gpointer		  instance,

					       GSignalMatchType	  mask,

					       guint		  signal_id,

					       GQuark		  detail,

					       GClosure		 *closure,

					       gpointer		  func,

					       gpointer		  data);

GLIB_AVAILABLE_IN_ALL

guint	 g_signal_handlers_unblock_matched    (gpointer		  instance,

					       GSignalMatchType	  mask,

					       guint		  signal_id,

					       GQuark		  detail,

					       GClosure		 *closure,

					       gpointer		  func,

					       gpointer		  data);

GLIB_AVAILABLE_IN_ALL

guint	 g_signal_handlers_disconnect_matched (gpointer		  instance,

					       GSignalMatchType	  mask,

					       guint		  signal_id,

					       GQuark		  detail,

					       GClosure		 *closure,

					       gpointer		  func,

					       gpointer		  data);

/* --- overriding and chaining --- */

GLIB_AVAILABLE_IN_ALL

void    g_signal_override_class_closure       (guint              signal_id,

                                               GType              instance_type,

                                               GClosure          *class_closure);

GLIB_AVAILABLE_IN_ALL

void    g_signal_override_class_handler       (const gchar       *signal_name,

                                               GType              instance_type,

                                               GCallback          class_handler);

GLIB_AVAILABLE_IN_ALL

void    g_signal_chain_from_overridden        (const GValue      *instance_and_params,

                                               GValue            *return_value);

GLIB_AVAILABLE_IN_ALL

void   g_signal_chain_from_overridden_handler (gpointer           instance,

                                               ...);

/* --- convenience --- */

/**

 * g_signal_connect:

 * @instance: the instance to connect to.

 * @detailed_signal: a string of the form "signal-name::detail".

 * @c_handler: the #GCallback to connect.

 * @data: data to pass to @c_handler calls.

 * 

 * Connects a #GCallback function to a signal for a particular object.

 * 

 * The handler will be called before the default handler of the signal.

 *

 * See [memory management of signal handlers][signal-memory-management] for

 * details on how to handle the return value and memory management of @data.

 * 

 * Returns: the handler ID, of type #gulong (always greater than 0 for successful connections)

 */

#define g_signal_connect(instance, detailed_signal, c_handler, data) \

    g_signal_connect_data ((instance), (detailed_signal), (c_handler), (data), NULL, (GConnectFlags) 0)

/**

 * g_signal_connect_after:

 * @instance: the instance to connect to.

 * @detailed_signal: a string of the form "signal-name::detail".

 * @c_handler: the #GCallback to connect.

 * @data: data to pass to @c_handler calls.

 * 

 * Connects a #GCallback function to a signal for a particular object.

 * 

 * The handler will be called after the default handler of the signal.

 * 

 * Returns: the handler ID, of type #gulong (always greater than 0 for successful connections)

 */

#define g_signal_connect_after(instance, detailed_signal, c_handler, data) \

    g_signal_connect_data ((instance), (detailed_signal), (c_handler), (data), NULL, G_CONNECT_AFTER)

/**

 * g_signal_connect_swapped:

 * @instance: the instance to connect to.

 * @detailed_signal: a string of the form "signal-name::detail".

 * @c_handler: the #GCallback to connect.

 * @data: data to pass to @c_handler calls.

 * 

 * Connects a #GCallback function to a signal for a particular object.

 * 

 * The instance on which the signal is emitted and @data will be swapped when 

 * calling the handler. This is useful when calling pre-existing functions to

 * operate purely on the @data, rather than the @instance: swapping the

 * parameters avoids the need to write a wrapper function.

 *

 * For example, this allows the shorter code:

 * |[

 * g_signal_connect_swapped (button, "clicked",

 *                           (GCallback) gtk_widget_hide, other_widget);

 * ]|

 *

 * Rather than the cumbersome:

 * |[

 * static void

 * button_clicked_cb (GtkButton *button, GtkWidget *other_widget)

 * {

 *     gtk_widget_hide (other_widget);

 * }

 *

 * ...

 *

 * g_signal_connect (button, "clicked",

 *                   (GCallback) button_clicked_cb, other_widget);

 * ]|

 * 

 * Returns: the handler ID, of type #gulong (always greater than 0 for successful connections)

 */

#define g_signal_connect_swapped(instance, detailed_signal, c_handler, data) \

    g_signal_connect_data ((instance), (detailed_signal), (c_handler), (data), NULL, G_CONNECT_SWAPPED)

/**

 * g_signal_handlers_disconnect_by_func:

 * @instance: The instance to remove handlers from.

 * @func: The C closure callback of the handlers (useless for non-C closures).

 * @data: The closure data of the handlers' closures.

 * 

 * Disconnects all handlers on an instance that match @func and @data.

 * 

 * Returns: The number of handlers that matched.

 */

#define	g_signal_handlers_disconnect_by_func(instance, func, data)						\

    g_signal_handlers_disconnect_matched ((instance),								\

					  (GSignalMatchType) (G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA),	\

					  0, 0, NULL, (func), (data))

/**

 * g_signal_handlers_disconnect_by_data:

 * @instance: The instance to remove handlers from

 * @data: the closure data of the handlers' closures

 *

 * Disconnects all handlers on an instance that match @data.

 *

 * Returns: The number of handlers that matched.

 *

 * Since: 2.32

 */

#define g_signal_handlers_disconnect_by_data(instance, data) \

  g_signal_handlers_disconnect_matched ((instance), G_SIGNAL_MATCH_DATA, 0, 0, NULL, NULL, (data))

/**

 * g_signal_handlers_block_by_func:

 * @instance: The instance to block handlers from.

 * @func: The C closure callback of the handlers (useless for non-C closures).

 * @data: The closure data of the handlers' closures.

 * 

 * Blocks all handlers on an instance that match @func and @data.

 * 

 * Returns: The number of handlers that matched.

 */

#define	g_signal_handlers_block_by_func(instance, func, data)							\

    g_signal_handlers_block_matched      ((instance),								\

				          (GSignalMatchType) (G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA),	\

				          0, 0, NULL, (func), (data))

/**

 * g_signal_handlers_unblock_by_func:

 * @instance: The instance to unblock handlers from.

 * @func: The C closure callback of the handlers (useless for non-C closures).

 * @data: The closure data of the handlers' closures.

 * 

 * Unblocks all handlers on an instance that match @func and @data.

 * 

 * Returns: The number of handlers that matched.

 */

#define	g_signal_handlers_unblock_by_func(instance, func, data)							\

    g_signal_handlers_unblock_matched    ((instance),								\

				          (GSignalMatchType) (G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA),	\

				          0, 0, NULL, (func), (data))

GLIB_AVAILABLE_IN_ALL

gboolean g_signal_accumulator_true_handled (GSignalInvocationHint *ihint,

					    GValue                *return_accu,

					    const GValue          *handler_return,

					    gpointer               dummy);

GLIB_AVAILABLE_IN_ALL

gboolean g_signal_accumulator_first_wins   (GSignalInvocationHint *ihint,

                                            GValue                *return_accu,

                                            const GValue          *handler_return,

                                            gpointer               dummy);

/*< private >*/

GLIB_AVAILABLE_IN_ALL

void	 g_signal_handlers_destroy	      (gpointer		  instance);

void	 _g_signals_destroy		      (GType		  itype);

G_END_DECLS

#endif /* __G_SIGNAL_H__ */