/* 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:
* |[<!-- language="C" -->
* @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:
* |[<!-- language="C" -->
* g_signal_connect_swapped (button, "clicked",
* (GCallback) gtk_widget_hide, other_widget);
* ]|
*
* Rather than the cumbersome:
* |[<!-- language="C" -->
* 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__ */