1/* GObject - GLib Type, Object, Parameter and Signal Library
2 * Copyright (C) 2000-2001 Red Hat, Inc.
3 *
4 * This library is free software; you can redistribute it and/or
5 * modify it under the terms of the GNU Lesser General Public
6 * License as published by the Free Software Foundation; either
7 * version 2.1 of the License, or (at your option) any later version.
8 *
9 * This library is distributed in the hope that it will be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
12 * Lesser General Public License for more details.
13 *
14 * You should have received a copy of the GNU Lesser General
15 * Public License along with this library; if not, see <http://www.gnu.org/licenses/>.
16 */
17#ifndef __G_SIGNAL_H__
18#define __G_SIGNAL_H__
19
20#if !defined (__GLIB_GOBJECT_H_INSIDE__) && !defined (GOBJECT_COMPILATION)
21#error "Only <glib-object.h> can be included directly."
22#endif
23
24#include <gobject/gclosure.h>
25#include <gobject/gvalue.h>
26#include <gobject/gparam.h>
27#include <gobject/gmarshal.h>
28
29G_BEGIN_DECLS
30
31/* --- typedefs --- */
32typedef struct _GSignalQuery GSignalQuery;
33typedef struct _GSignalInvocationHint GSignalInvocationHint;
34/**
35 * GSignalCMarshaller:
36 *
37 * This is the signature of marshaller functions, required to marshall
38 * arrays of parameter values to signal emissions into C language callback
39 * invocations. It is merely an alias to #GClosureMarshal since the #GClosure
40 * mechanism takes over responsibility of actual function invocation for the
41 * signal system.
42 */
43typedef GClosureMarshal GSignalCMarshaller;
44/**
45 * GSignalCVaMarshaller:
46 *
47 * This is the signature of va_list marshaller functions, an optional
48 * marshaller that can be used in some situations to avoid
49 * marshalling the signal argument into GValues.
50 */
51typedef GVaClosureMarshal GSignalCVaMarshaller;
52/**
53 * GSignalEmissionHook:
54 * @ihint: Signal invocation hint, see #GSignalInvocationHint.
55 * @n_param_values: the number of parameters to the function, including
56 * the instance on which the signal was emitted.
57 * @param_values: (array length=n_param_values): the instance on which
58 * the signal was emitted, followed by the parameters of the emission.
59 * @data: user data associated with the hook.
60 *
61 * A simple function pointer to get invoked when the signal is emitted. This
62 * allows you to tie a hook to the signal type, so that it will trap all
63 * emissions of that signal, from any object.
64 *
65 * You may not attach these to signals created with the #G_SIGNAL_NO_HOOKS flag.
66 *
67 * Returns: whether it wants to stay connected. If it returns %FALSE, the signal
68 * hook is disconnected (and destroyed).
69 */
70typedef gboolean (*GSignalEmissionHook) (GSignalInvocationHint *ihint,
71 guint n_param_values,
72 const GValue *param_values,
73 gpointer data);
74/**
75 * GSignalAccumulator:
76 * @ihint: Signal invocation hint, see #GSignalInvocationHint.
77 * @return_accu: Accumulator to collect callback return values in, this
78 * is the return value of the current signal emission.
79 * @handler_return: A #GValue holding the return value of the signal handler.
80 * @data: Callback data that was specified when creating the signal.
81 *
82 * The signal accumulator is a special callback function that can be used
83 * to collect return values of the various callbacks that are called
84 * during a signal emission. The signal accumulator is specified at signal
85 * creation time, if it is left %NULL, no accumulation of callback return
86 * values is performed. The return value of signal emissions is then the
87 * value returned by the last callback.
88 *
89 * Returns: The accumulator function returns whether the signal emission
90 * should be aborted. Returning %FALSE means to abort the
91 * current emission and %TRUE is returned for continuation.
92 */
93typedef gboolean (*GSignalAccumulator) (GSignalInvocationHint *ihint,
94 GValue *return_accu,
95 const GValue *handler_return,
96 gpointer data);
97
98
99/* --- run, match and connect types --- */
100/**
101 * GSignalFlags:
102 * @G_SIGNAL_RUN_FIRST: Invoke the object method handler in the first emission stage.
103 * @G_SIGNAL_RUN_LAST: Invoke the object method handler in the third emission stage.
104 * @G_SIGNAL_RUN_CLEANUP: Invoke the object method handler in the last emission stage.
105 * @G_SIGNAL_NO_RECURSE: Signals being emitted for an object while currently being in
106 * emission for this very object will not be emitted recursively,
107 * but instead cause the first emission to be restarted.
108 * @G_SIGNAL_DETAILED: This signal supports "::detail" appendices to the signal name
109 * upon handler connections and emissions.
110 * @G_SIGNAL_ACTION: Action signals are signals that may freely be emitted on alive
111 * objects from user code via g_signal_emit() and friends, without
112 * the need of being embedded into extra code that performs pre or
113 * post emission adjustments on the object. They can also be thought
114 * of as object methods which can be called generically by
115 * third-party code.
116 * @G_SIGNAL_NO_HOOKS: No emissions hooks are supported for this signal.
117 * @G_SIGNAL_MUST_COLLECT: Varargs signal emission will always collect the
118 * arguments, even if there are no signal handlers connected. Since 2.30.
119 * @G_SIGNAL_DEPRECATED: The signal is deprecated and will be removed
120 * in a future version. A warning will be generated if it is connected while
121 * running with G_ENABLE_DIAGNOSTIC=1. Since 2.32.
122 * @G_SIGNAL_ACCUMULATOR_FIRST_RUN: Only used in #GSignalAccumulator accumulator
123 * functions for the #GSignalInvocationHint::run_type field to mark the first
124 * call to the accumulator function for a signal emission. Since 2.68.
125 *
126 * The signal flags are used to specify a signal's behaviour, the overall
127 * signal description outlines how especially the RUN flags control the
128 * stages of a signal emission.
129 */
130typedef enum
131{
132 G_SIGNAL_RUN_FIRST = 1 << 0,
133 G_SIGNAL_RUN_LAST = 1 << 1,
134 G_SIGNAL_RUN_CLEANUP = 1 << 2,
135 G_SIGNAL_NO_RECURSE = 1 << 3,
136 G_SIGNAL_DETAILED = 1 << 4,
137 G_SIGNAL_ACTION = 1 << 5,
138 G_SIGNAL_NO_HOOKS = 1 << 6,
139 G_SIGNAL_MUST_COLLECT = 1 << 7,
140 G_SIGNAL_DEPRECATED = 1 << 8,
141 /* normal signal flags until 1 << 16 */
142 G_SIGNAL_ACCUMULATOR_FIRST_RUN = 1 << 17,
143} GSignalFlags;
144/**
145 * G_SIGNAL_FLAGS_MASK:
146 *
147 * A mask for all #GSignalFlags bits.
148 */
149#define G_SIGNAL_FLAGS_MASK 0x1ff
150/**
151 * GConnectFlags:
152 * @G_CONNECT_AFTER: whether the handler should be called before or after the
153 * default handler of the signal.
154 * @G_CONNECT_SWAPPED: whether the instance and data should be swapped when
155 * calling the handler; see g_signal_connect_swapped() for an example.
156 *
157 * The connection flags are used to specify the behaviour of a signal's
158 * connection.
159 */
160typedef enum
161{
162 G_CONNECT_AFTER = 1 << 0,
163 G_CONNECT_SWAPPED = 1 << 1
164} GConnectFlags;
165/**
166 * GSignalMatchType:
167 * @G_SIGNAL_MATCH_ID: The signal id must be equal.
168 * @G_SIGNAL_MATCH_DETAIL: The signal detail must be equal.
169 * @G_SIGNAL_MATCH_CLOSURE: The closure must be the same.
170 * @G_SIGNAL_MATCH_FUNC: The C closure callback must be the same.
171 * @G_SIGNAL_MATCH_DATA: The closure data must be the same.
172 * @G_SIGNAL_MATCH_UNBLOCKED: Only unblocked signals may be matched.
173 *
174 * The match types specify what g_signal_handlers_block_matched(),
175 * g_signal_handlers_unblock_matched() and g_signal_handlers_disconnect_matched()
176 * match signals by.
177 */
178typedef enum
179{
180 G_SIGNAL_MATCH_ID = 1 << 0,
181 G_SIGNAL_MATCH_DETAIL = 1 << 1,
182 G_SIGNAL_MATCH_CLOSURE = 1 << 2,
183 G_SIGNAL_MATCH_FUNC = 1 << 3,
184 G_SIGNAL_MATCH_DATA = 1 << 4,
185 G_SIGNAL_MATCH_UNBLOCKED = 1 << 5
186} GSignalMatchType;
187/**
188 * G_SIGNAL_MATCH_MASK:
189 *
190 * A mask for all #GSignalMatchType bits.
191 */
192#define G_SIGNAL_MATCH_MASK 0x3f
193/**
194 * G_SIGNAL_TYPE_STATIC_SCOPE:
195 *
196 * This macro flags signal argument types for which the signal system may
197 * assume that instances thereof remain persistent across all signal emissions
198 * they are used in. This is only useful for non ref-counted, value-copy types.
199 *
200 * To flag a signal argument in this way, add `| G_SIGNAL_TYPE_STATIC_SCOPE`
201 * to the corresponding argument of g_signal_new().
202 * |[
203 * g_signal_new ("size_request",
204 * G_TYPE_FROM_CLASS (gobject_class),
205 * G_SIGNAL_RUN_FIRST,
206 * G_STRUCT_OFFSET (GtkWidgetClass, size_request),
207 * NULL, NULL,
208 * _gtk_marshal_VOID__BOXED,
209 * G_TYPE_NONE, 1,
210 * GTK_TYPE_REQUISITION | G_SIGNAL_TYPE_STATIC_SCOPE);
211 * ]|
212 */
213#define G_SIGNAL_TYPE_STATIC_SCOPE (G_TYPE_FLAG_RESERVED_ID_BIT)
214
215
216/* --- signal information --- */
217/**
218 * GSignalInvocationHint:
219 * @signal_id: The signal id of the signal invoking the callback
220 * @detail: The detail passed on for this emission
221 * @run_type: The stage the signal emission is currently in, this
222 * field will contain one of %G_SIGNAL_RUN_FIRST,
223 * %G_SIGNAL_RUN_LAST or %G_SIGNAL_RUN_CLEANUP and %G_SIGNAL_ACCUMULATOR_FIRST_RUN.
224 * %G_SIGNAL_ACCUMULATOR_FIRST_RUN is only set for the first run of the accumulator
225 * function for a signal emission.
226 *
227 * The #GSignalInvocationHint structure is used to pass on additional information
228 * to callbacks during a signal emission.
229 */
230struct _GSignalInvocationHint
231{
232 guint signal_id;
233 GQuark detail;
234 GSignalFlags run_type;
235};
236/**
237 * GSignalQuery:
238 * @signal_id: The signal id of the signal being queried, or 0 if the
239 * signal to be queried was unknown.
240 * @signal_name: The signal name.
241 * @itype: The interface/instance type that this signal can be emitted for.
242 * @signal_flags: The signal flags as passed in to g_signal_new().
243 * @return_type: The return type for user callbacks.
244 * @n_params: The number of parameters that user callbacks take.
245 * @param_types: (array length=n_params): The individual parameter types for
246 * user callbacks, note that the effective callback signature is:
247 * |[<!-- language="C" -->
248 * @return_type callback (#gpointer data1,
249 * [param_types param_names,]
250 * gpointer data2);
251 * ]|
252 *
253 * A structure holding in-depth information for a specific signal. It is
254 * filled in by the g_signal_query() function.
255 */
256struct _GSignalQuery
257{
258 guint signal_id;
259 const gchar *signal_name;
260 GType itype;
261 GSignalFlags signal_flags;
262 GType return_type; /* mangled with G_SIGNAL_TYPE_STATIC_SCOPE flag */
263 guint n_params;
264 const GType *param_types; /* mangled with G_SIGNAL_TYPE_STATIC_SCOPE flag */
265};
266
267
268/* --- signals --- */
269GLIB_AVAILABLE_IN_ALL
270guint g_signal_newv (const gchar *signal_name,
271 GType itype,
272 GSignalFlags signal_flags,
273 GClosure *class_closure,
274 GSignalAccumulator accumulator,
275 gpointer accu_data,
276 GSignalCMarshaller c_marshaller,
277 GType return_type,
278 guint n_params,
279 GType *param_types);
280GLIB_AVAILABLE_IN_ALL
281guint g_signal_new_valist (const gchar *signal_name,
282 GType itype,
283 GSignalFlags signal_flags,
284 GClosure *class_closure,
285 GSignalAccumulator accumulator,
286 gpointer accu_data,
287 GSignalCMarshaller c_marshaller,
288 GType return_type,
289 guint n_params,
290 va_list args);
291GLIB_AVAILABLE_IN_ALL
292guint g_signal_new (const gchar *signal_name,
293 GType itype,
294 GSignalFlags signal_flags,
295 guint class_offset,
296 GSignalAccumulator accumulator,
297 gpointer accu_data,
298 GSignalCMarshaller c_marshaller,
299 GType return_type,
300 guint n_params,
301 ...);
302GLIB_AVAILABLE_IN_ALL
303guint g_signal_new_class_handler (const gchar *signal_name,
304 GType itype,
305 GSignalFlags signal_flags,
306 GCallback class_handler,
307 GSignalAccumulator accumulator,
308 gpointer accu_data,
309 GSignalCMarshaller c_marshaller,
310 GType return_type,
311 guint n_params,
312 ...);
313GLIB_AVAILABLE_IN_ALL
314void g_signal_set_va_marshaller (guint signal_id,
315 GType instance_type,
316 GSignalCVaMarshaller va_marshaller);
317
318GLIB_AVAILABLE_IN_ALL
319void g_signal_emitv (const GValue *instance_and_params,
320 guint signal_id,
321 GQuark detail,
322 GValue *return_value);
323GLIB_AVAILABLE_IN_ALL
324void g_signal_emit_valist (gpointer instance,
325 guint signal_id,
326 GQuark detail,
327 va_list var_args);
328GLIB_AVAILABLE_IN_ALL
329void g_signal_emit (gpointer instance,
330 guint signal_id,
331 GQuark detail,
332 ...);
333GLIB_AVAILABLE_IN_ALL
334void g_signal_emit_by_name (gpointer instance,
335 const gchar *detailed_signal,
336 ...);
337GLIB_AVAILABLE_IN_ALL
338guint g_signal_lookup (const gchar *name,
339 GType itype);
340GLIB_AVAILABLE_IN_ALL
341const gchar * g_signal_name (guint signal_id);
342GLIB_AVAILABLE_IN_ALL
343void g_signal_query (guint signal_id,
344 GSignalQuery *query);
345GLIB_AVAILABLE_IN_ALL
346guint* g_signal_list_ids (GType itype,
347 guint *n_ids);
348GLIB_AVAILABLE_IN_2_66
349gboolean g_signal_is_valid_name (const gchar *name);
350GLIB_AVAILABLE_IN_ALL
351gboolean g_signal_parse_name (const gchar *detailed_signal,
352 GType itype,
353 guint *signal_id_p,
354 GQuark *detail_p,
355 gboolean force_detail_quark);
356GLIB_AVAILABLE_IN_ALL
357GSignalInvocationHint* g_signal_get_invocation_hint (gpointer instance);
358
359
360/* --- signal emissions --- */
361GLIB_AVAILABLE_IN_ALL
362void g_signal_stop_emission (gpointer instance,
363 guint signal_id,
364 GQuark detail);
365GLIB_AVAILABLE_IN_ALL
366void g_signal_stop_emission_by_name (gpointer instance,
367 const gchar *detailed_signal);
368GLIB_AVAILABLE_IN_ALL
369gulong g_signal_add_emission_hook (guint signal_id,
370 GQuark detail,
371 GSignalEmissionHook hook_func,
372 gpointer hook_data,
373 GDestroyNotify data_destroy);
374GLIB_AVAILABLE_IN_ALL
375void g_signal_remove_emission_hook (guint signal_id,
376 gulong hook_id);
377
378
379/* --- signal handlers --- */
380GLIB_AVAILABLE_IN_ALL
381gboolean g_signal_has_handler_pending (gpointer instance,
382 guint signal_id,
383 GQuark detail,
384 gboolean may_be_blocked);
385GLIB_AVAILABLE_IN_ALL
386gulong g_signal_connect_closure_by_id (gpointer instance,
387 guint signal_id,
388 GQuark detail,
389 GClosure *closure,
390 gboolean after);
391GLIB_AVAILABLE_IN_ALL
392gulong g_signal_connect_closure (gpointer instance,
393 const gchar *detailed_signal,
394 GClosure *closure,
395 gboolean after);
396GLIB_AVAILABLE_IN_ALL
397gulong g_signal_connect_data (gpointer instance,
398 const gchar *detailed_signal,
399 GCallback c_handler,
400 gpointer data,
401 GClosureNotify destroy_data,
402 GConnectFlags connect_flags);
403GLIB_AVAILABLE_IN_ALL
404void g_signal_handler_block (gpointer instance,
405 gulong handler_id);
406GLIB_AVAILABLE_IN_ALL
407void g_signal_handler_unblock (gpointer instance,
408 gulong handler_id);
409GLIB_AVAILABLE_IN_ALL
410void g_signal_handler_disconnect (gpointer instance,
411 gulong handler_id);
412GLIB_AVAILABLE_IN_ALL
413gboolean g_signal_handler_is_connected (gpointer instance,
414 gulong handler_id);
415GLIB_AVAILABLE_IN_ALL
416gulong g_signal_handler_find (gpointer instance,
417 GSignalMatchType mask,
418 guint signal_id,
419 GQuark detail,
420 GClosure *closure,
421 gpointer func,
422 gpointer data);
423GLIB_AVAILABLE_IN_ALL
424guint g_signal_handlers_block_matched (gpointer instance,
425 GSignalMatchType mask,
426 guint signal_id,
427 GQuark detail,
428 GClosure *closure,
429 gpointer func,
430 gpointer data);
431GLIB_AVAILABLE_IN_ALL
432guint g_signal_handlers_unblock_matched (gpointer instance,
433 GSignalMatchType mask,
434 guint signal_id,
435 GQuark detail,
436 GClosure *closure,
437 gpointer func,
438 gpointer data);
439GLIB_AVAILABLE_IN_ALL
440guint g_signal_handlers_disconnect_matched (gpointer instance,
441 GSignalMatchType mask,
442 guint signal_id,
443 GQuark detail,
444 GClosure *closure,
445 gpointer func,
446 gpointer data);
447
448GLIB_AVAILABLE_IN_2_62
449void g_clear_signal_handler (gulong *handler_id_ptr,
450 gpointer instance);
451
452#define g_clear_signal_handler(handler_id_ptr, instance) \
453 G_STMT_START { \
454 gpointer const _instance = (instance); \
455 gulong *const _handler_id_ptr = (handler_id_ptr); \
456 const gulong _handler_id = *_handler_id_ptr; \
457 \
458 if (_handler_id > 0) \
459 { \
460 *_handler_id_ptr = 0; \
461 g_signal_handler_disconnect (_instance, _handler_id); \
462 } \
463 } G_STMT_END \
464 GLIB_AVAILABLE_MACRO_IN_2_62
465
466/* --- overriding and chaining --- */
467GLIB_AVAILABLE_IN_ALL
468void g_signal_override_class_closure (guint signal_id,
469 GType instance_type,
470 GClosure *class_closure);
471GLIB_AVAILABLE_IN_ALL
472void g_signal_override_class_handler (const gchar *signal_name,
473 GType instance_type,
474 GCallback class_handler);
475GLIB_AVAILABLE_IN_ALL
476void g_signal_chain_from_overridden (const GValue *instance_and_params,
477 GValue *return_value);
478GLIB_AVAILABLE_IN_ALL
479void g_signal_chain_from_overridden_handler (gpointer instance,
480 ...);
481
482
483/* --- convenience --- */
484/**
485 * g_signal_connect:
486 * @instance: the instance to connect to.
487 * @detailed_signal: a string of the form "signal-name::detail".
488 * @c_handler: the #GCallback to connect.
489 * @data: data to pass to @c_handler calls.
490 *
491 * Connects a #GCallback function to a signal for a particular object.
492 *
493 * The handler will be called before the default handler of the signal.
494 *
495 * See [memory management of signal handlers][signal-memory-management] for
496 * details on how to handle the return value and memory management of @data.
497 *
498 * Returns: the handler ID, of type #gulong (always greater than 0 for successful connections)
499 */
500#define g_signal_connect(instance, detailed_signal, c_handler, data) \
501 g_signal_connect_data ((instance), (detailed_signal), (c_handler), (data), NULL, (GConnectFlags) 0)
502/**
503 * g_signal_connect_after:
504 * @instance: the instance to connect to.
505 * @detailed_signal: a string of the form "signal-name::detail".
506 * @c_handler: the #GCallback to connect.
507 * @data: data to pass to @c_handler calls.
508 *
509 * Connects a #GCallback function to a signal for a particular object.
510 *
511 * The handler will be called after the default handler of the signal.
512 *
513 * Returns: the handler ID, of type #gulong (always greater than 0 for successful connections)
514 */
515#define g_signal_connect_after(instance, detailed_signal, c_handler, data) \
516 g_signal_connect_data ((instance), (detailed_signal), (c_handler), (data), NULL, G_CONNECT_AFTER)
517/**
518 * g_signal_connect_swapped:
519 * @instance: the instance to connect to.
520 * @detailed_signal: a string of the form "signal-name::detail".
521 * @c_handler: the #GCallback to connect.
522 * @data: data to pass to @c_handler calls.
523 *
524 * Connects a #GCallback function to a signal for a particular object.
525 *
526 * The instance on which the signal is emitted and @data will be swapped when
527 * calling the handler. This is useful when calling pre-existing functions to
528 * operate purely on the @data, rather than the @instance: swapping the
529 * parameters avoids the need to write a wrapper function.
530 *
531 * For example, this allows the shorter code:
532 * |[<!-- language="C" -->
533 * g_signal_connect_swapped (button, "clicked",
534 * (GCallback) gtk_widget_hide, other_widget);
535 * ]|
536 *
537 * Rather than the cumbersome:
538 * |[<!-- language="C" -->
539 * static void
540 * button_clicked_cb (GtkButton *button, GtkWidget *other_widget)
541 * {
542 * gtk_widget_hide (other_widget);
543 * }
544 *
545 * ...
546 *
547 * g_signal_connect (button, "clicked",
548 * (GCallback) button_clicked_cb, other_widget);
549 * ]|
550 *
551 * Returns: the handler ID, of type #gulong (always greater than 0 for successful connections)
552 */
553#define g_signal_connect_swapped(instance, detailed_signal, c_handler, data) \
554 g_signal_connect_data ((instance), (detailed_signal), (c_handler), (data), NULL, G_CONNECT_SWAPPED)
555/**
556 * g_signal_handlers_disconnect_by_func:
557 * @instance: The instance to remove handlers from.
558 * @func: The C closure callback of the handlers (useless for non-C closures).
559 * @data: The closure data of the handlers' closures.
560 *
561 * Disconnects all handlers on an instance that match @func and @data.
562 *
563 * Returns: The number of handlers that matched.
564 */
565#define g_signal_handlers_disconnect_by_func(instance, func, data) \
566 g_signal_handlers_disconnect_matched ((instance), \
567 (GSignalMatchType) (G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA), \
568 0, 0, NULL, (func), (data))
569
570/**
571 * g_signal_handlers_disconnect_by_data:
572 * @instance: The instance to remove handlers from
573 * @data: the closure data of the handlers' closures
574 *
575 * Disconnects all handlers on an instance that match @data.
576 *
577 * Returns: The number of handlers that matched.
578 *
579 * Since: 2.32
580 */
581#define g_signal_handlers_disconnect_by_data(instance, data) \
582 g_signal_handlers_disconnect_matched ((instance), G_SIGNAL_MATCH_DATA, 0, 0, NULL, NULL, (data))
583
584/**
585 * g_signal_handlers_block_by_func:
586 * @instance: The instance to block handlers from.
587 * @func: The C closure callback of the handlers (useless for non-C closures).
588 * @data: The closure data of the handlers' closures.
589 *
590 * Blocks all handlers on an instance that match @func and @data.
591 *
592 * Returns: The number of handlers that matched.
593 */
594#define g_signal_handlers_block_by_func(instance, func, data) \
595 g_signal_handlers_block_matched ((instance), \
596 (GSignalMatchType) (G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA), \
597 0, 0, NULL, (func), (data))
598/**
599 * g_signal_handlers_unblock_by_func:
600 * @instance: The instance to unblock handlers from.
601 * @func: The C closure callback of the handlers (useless for non-C closures).
602 * @data: The closure data of the handlers' closures.
603 *
604 * Unblocks all handlers on an instance that match @func and @data.
605 *
606 * Returns: The number of handlers that matched.
607 */
608#define g_signal_handlers_unblock_by_func(instance, func, data) \
609 g_signal_handlers_unblock_matched ((instance), \
610 (GSignalMatchType) (G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA), \
611 0, 0, NULL, (func), (data))
612
613
614GLIB_AVAILABLE_IN_ALL
615gboolean g_signal_accumulator_true_handled (GSignalInvocationHint *ihint,
616 GValue *return_accu,
617 const GValue *handler_return,
618 gpointer dummy);
619
620GLIB_AVAILABLE_IN_ALL
621gboolean g_signal_accumulator_first_wins (GSignalInvocationHint *ihint,
622 GValue *return_accu,
623 const GValue *handler_return,
624 gpointer dummy);
625
626/*< private >*/
627GLIB_AVAILABLE_IN_ALL
628void g_signal_handlers_destroy (gpointer instance);
629void _g_signals_destroy (GType itype);
630
631G_END_DECLS
632
633#endif /* __G_SIGNAL_H__ */
634

source code of gtk/subprojects/glib/gobject/gsignal.h