gobject/gsignal.h

   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 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, write to the
  16  * Free Software Foundation, Inc., 59 Temple Place, Suite 330,
  17  * Boston, MA 02111-1307, USA.
  18  */
  19 #ifndef __G_SIGNAL_H__
  20 #define __G_SIGNAL_H__
  21
  22 #if !defined (__GLIB_GOBJECT_H_INSIDE__) && !defined (GOBJECT_COMPILATION)
  23 #error "Only <glib-object.h> can be included directly."
  24 #endif
  25
  26 #include        <gobject/gclosure.h>
  27 #include        <gobject/gvalue.h>
  28 #include        <gobject/gparam.h>
  29 #include        <gobject/gmarshal.h>
  30
  31 G_BEGIN_DECLS
  32
  33 /* --- typedefs --- */
  34 typedef struct _GSignalQuery             GSignalQuery;
  35 typedef struct _GSignalInvocationHint    GSignalInvocationHint;
  36 /**
  37  * GSignalCMarshaller:
  38  *
  39  * This is the signature of marshaller functions, required to marshall
  40  * arrays of parameter values to signal emissions into C language callback
  41  * invocations. It is merely an alias to #GClosureMarshal since the #GClosure
  42  * mechanism takes over responsibility of actual function invocation for the
  43  * signal system.
  44  */
  45 typedef GClosureMarshal                  GSignalCMarshaller;
  46 /**
  47  * GSignalCVaMarshaller:
  48  *
  49  * This is the signature of va_list marshaller functions, an optional
  50  * marshaller that can be used in some situations to avoid
  51  * marshalling the signal argument into GValues.
  52  */
  53 typedef GVaClosureMarshal                GSignalCVaMarshaller;
  54 /**
  55  * GSignalEmissionHook:
  56  * @ihint: Signal invocation hint, see #GSignalInvocationHint.
  57  * @n_param_values: the number of parameters to the function, including
  58  *  the instance on which the signal was emitted.
  59  * @param_values: (array length=n_param_values): the instance on which
  60  *  the signal was emitted, followed by the parameters of the emission.
  61  * @data: user data associated with the hook.
  62  *
  63  * A simple function pointer to get invoked when the signal is emitted. This
  64  * allows you to tie a hook to the signal type, so that it will trap all
  65  * emissions of that signal, from any object.
  66  *
  67  * You may not attach these to signals created with the #G_SIGNAL_NO_HOOKS flag.
  68  *
  69  * Returns: whether it wants to stay connected. If it returns %FALSE, the signal
  70  *  hook is disconnected (and destroyed).
  71  */
  72 typedef gboolean (*GSignalEmissionHook) (GSignalInvocationHint *ihint,
  73                                          guint                  n_param_values,
  74                                          const GValue          *param_values,
  75                                          gpointer               data);
  76 /**
  77  * GSignalAccumulator:
  78  * @ihint: Signal invocation hint, see #GSignalInvocationHint.
  79  * @return_accu: Accumulator to collect callback return values in, this
  80  *  is the return value of the current signal emission.
  81  * @handler_return: A #GValue holding the return value of the signal handler.
  82  * @data: Callback data that was specified when creating the signal.
  83  *
  84  * The signal accumulator is a special callback function that can be used
  85  * to collect return values of the various callbacks that are called
  86  * during a signal emission. The signal accumulator is specified at signal
  87  * creation time, if it is left %NULL, no accumulation of callback return
  88  * values is performed. The return value of signal emissions is then the
  89  * value returned by the last callback.
  90  *
  91  * Returns: The accumulator function returns whether the signal emission
  92  *  should be aborted. Returning %FALSE means to abort the
  93  *  current emission and %TRUE is returned for continuation.
  94  */
  95 typedef gboolean (*GSignalAccumulator)  (GSignalInvocationHint *ihint,
  96                                          GValue                *return_accu,
  97                                          const GValue          *handler_return,
  98                                          gpointer               data);
  99
 100
 101 /* --- run, match and connect types --- */
 102 /**
 103  * GSignalFlags:
 104  * @G_SIGNAL_RUN_FIRST: Invoke the object method handler in the first emission stage.
 105  * @G_SIGNAL_RUN_LAST: Invoke the object method handler in the third emission stage.
 106  * @G_SIGNAL_RUN_CLEANUP: Invoke the object method handler in the last emission stage.
 107  * @G_SIGNAL_NO_RECURSE: Signals being emitted for an object while currently being in
 108  *  emission for this very object will not be emitted recursively,
 109  *  but instead cause the first emission to be restarted.
 110  * @G_SIGNAL_DETAILED: This signal supports "::detail" appendices to the signal name
 111  *  upon handler connections and emissions.
 112  * @G_SIGNAL_ACTION: Action signals are signals that may freely be emitted on alive
 113  *  objects from user code via g_signal_emit() and friends, without
 114  *  the need of being embedded into extra code that performs pre or
 115  *  post emission adjustments on the object. They can also be thought
 116  *  of as object methods which can be called generically by
 117  *  third-party code.
 118  * @G_SIGNAL_NO_HOOKS: No emissions hooks are supported for this signal.
 119  * @G_SIGNAL_MUST_COLLECT: Varargs signal emission will always collect the
 120  *   arguments, even if there are no signal handlers connected.  Since 2.30.
 121  * @G_SIGNAL_DEPRECATED: The signal is deprecated and will be removed
 122  *   in a future version. A warning will be generated if it is connected while
 123  *   running with G_ENABLE_DIAGNOSTIC=1.  Since 2.32.
 124  *
 125  * The signal flags are used to specify a signal's behaviour, the overall
 126  * signal description outlines how especially the RUN flags control the
 127  * stages of a signal emission.
 128  */
 129 typedef enum
 130 {
 131   G_SIGNAL_RUN_FIRST    = 1 << 0,
 132   G_SIGNAL_RUN_LAST     = 1 << 1,
 133   G_SIGNAL_RUN_CLEANUP  = 1 << 2,
 134   G_SIGNAL_NO_RECURSE   = 1 << 3,
 135   G_SIGNAL_DETAILED     = 1 << 4,
 136   G_SIGNAL_ACTION       = 1 << 5,
 137   G_SIGNAL_NO_HOOKS     = 1 << 6,
 138   G_SIGNAL_MUST_COLLECT = 1 << 7,
 139   G_SIGNAL_DEPRECATED   = 1 << 8
 140 } GSignalFlags;
 141 /**
 142  * G_SIGNAL_FLAGS_MASK:
 143  *
 144  * A mask for all #GSignalFlags bits.
 145  */
 146 #define G_SIGNAL_FLAGS_MASK  0x1ff
 147 /**
 148  * GConnectFlags:
 149  * @G_CONNECT_AFTER: whether the handler should be called before or after the
 150  *  default handler of the signal.
 151  * @G_CONNECT_SWAPPED: whether the instance and data should be swapped when
 152  *  calling the handler.
 153  *
 154  * The connection flags are used to specify the behaviour of a signal's
 155  * connection.
 156  */
 157 typedef enum
 158 {
 159   G_CONNECT_AFTER       = 1 << 0,
 160   G_CONNECT_SWAPPED     = 1 << 1
 161 } GConnectFlags;
 162 /**
 163  * GSignalMatchType:
 164  * @G_SIGNAL_MATCH_ID: The signal id must be equal.
 165  * @G_SIGNAL_MATCH_DETAIL: The signal detail be equal.
 166  * @G_SIGNAL_MATCH_CLOSURE: The closure must be the same.
 167  * @G_SIGNAL_MATCH_FUNC: The C closure callback must be the same.
 168  * @G_SIGNAL_MATCH_DATA: The closure data must be the same.
 169  * @G_SIGNAL_MATCH_UNBLOCKED: Only unblocked signals may matched.
 170  *
 171  * The match types specify what g_signal_handlers_block_matched(),
 172  * g_signal_handlers_unblock_matched() and g_signal_handlers_disconnect_matched()
 173  * match signals by.
 174  */
 175 typedef enum
 176 {
 177   G_SIGNAL_MATCH_ID        = 1 << 0,
 178   G_SIGNAL_MATCH_DETAIL    = 1 << 1,
 179   G_SIGNAL_MATCH_CLOSURE   = 1 << 2,
 180   G_SIGNAL_MATCH_FUNC      = 1 << 3,
 181   G_SIGNAL_MATCH_DATA      = 1 << 4,
 182   G_SIGNAL_MATCH_UNBLOCKED = 1 << 5
 183 } GSignalMatchType;
 184 /**
 185  * G_SIGNAL_MATCH_MASK:
 186  *
 187  * A mask for all #GSignalMatchType bits.
 188  */
 189 #define G_SIGNAL_MATCH_MASK  0x3f
 190 /**
 191  * G_SIGNAL_TYPE_STATIC_SCOPE:
 192  *
 193  * This macro flags signal argument types for which the signal system may
 194  * assume that instances thereof remain persistent across all signal emissions
 195  * they are used in. This is only useful for non ref-counted, value-copy types.
 196  *
 197  * To flag a signal argument in this way, add
 198  * <literal>| G_SIGNAL_TYPE_STATIC_SCOPE</literal> to the corresponding argument
 199  * of g_signal_new().
 200  * |[
 201  * g_signal_new ("size_request",
 202  *   G_TYPE_FROM_CLASS (gobject_class),
 203  *       G_SIGNAL_RUN_FIRST,
 204  *       G_STRUCT_OFFSET (GtkWidgetClass, size_request),
 205  *       NULL, NULL,
 206  *       _gtk_marshal_VOID__BOXED,
 207  *       G_TYPE_NONE, 1,
 208  *       GTK_TYPE_REQUISITION | G_SIGNAL_TYPE_STATIC_SCOPE);
 209  * ]|
 210  */
 211 #define G_SIGNAL_TYPE_STATIC_SCOPE (G_TYPE_FLAG_RESERVED_ID_BIT)
 212
 213
 214 /* --- signal information --- */
 215 /**
 216  * GSignalInvocationHint:
 217  * @signal_id: The signal id of the signal invoking the callback
 218  * @detail: The detail passed on for this emission
 219  * @run_type: The stage the signal emission is currently in, this
 220  *  field will contain one of %G_SIGNAL_RUN_FIRST,
 221  *  %G_SIGNAL_RUN_LAST or %G_SIGNAL_RUN_CLEANUP.
 222  *
 223  * The #GSignalInvocationHint structure is used to pass on additional information
 224  * to callbacks during a signal emission.
 225  */
 226 struct _GSignalInvocationHint
 227 {
 228   guint         signal_id;
 229   GQuark        detail;
 230   GSignalFlags  run_type;
 231 };
 232 /**
 233  * GSignalQuery:
 234  * @signal_id: The signal id of the signal being queried, or 0 if the
 235  *  signal to be queried was unknown.
 236  * @signal_name: The signal name.
 237  * @itype: The interface/instance type that this signal can be emitted for.
 238  * @signal_flags: The signal flags as passed in to g_signal_new().
 239  * @return_type: The return type for user callbacks.
 240  * @n_params: The number of parameters that user callbacks take.
 241  * @param_types: (array length=n_params): The individual parameter types for
 242  *  user callbacks, note that the effective callback signature is:
 243  *  <programlisting>
 244  *  @return_type callback (#gpointer     data1,
 245  *  [param_types param_names,]
 246  *  gpointer     data2);
 247  *  </programlisting>
 248  *
 249  * A structure holding in-depth information for a specific signal. It is
 250  * filled in by the g_signal_query() function.
 251  */
 252 struct _GSignalQuery
 253 {
 254   guint         signal_id;
 255   const gchar  *signal_name;
 256   GType         itype;
 257   GSignalFlags  signal_flags;
 258   GType         return_type; /* mangled with G_SIGNAL_TYPE_STATIC_SCOPE flag */
 259   guint         n_params;
 260   const GType  *param_types; /* mangled with G_SIGNAL_TYPE_STATIC_SCOPE flag */
 261 };
 262
 263
 264 /* --- signals --- */
 265 GLIB_AVAILABLE_IN_ALL
 266 guint                 g_signal_newv         (const gchar        *signal_name,
 267                                              GType               itype,
 268                                              GSignalFlags        signal_flags,
 269                                              GClosure           *class_closure,
 270                                              GSignalAccumulator  accumulator,
 271                                              gpointer            accu_data,
 272                                              GSignalCMarshaller  c_marshaller,
 273                                              GType               return_type,
 274                                              guint               n_params,
 275                                              GType              *param_types);
 276 GLIB_AVAILABLE_IN_ALL
 277 guint                 g_signal_new_valist   (const gchar        *signal_name,
 278                                              GType               itype,
 279                                              GSignalFlags        signal_flags,
 280                                              GClosure           *class_closure,
 281                                              GSignalAccumulator  accumulator,
 282                                              gpointer            accu_data,
 283                                              GSignalCMarshaller  c_marshaller,
 284                                              GType               return_type,
 285                                              guint               n_params,
 286                                              va_list             args);
 287 GLIB_AVAILABLE_IN_ALL
 288 guint                 g_signal_new          (const gchar        *signal_name,
 289                                              GType               itype,
 290                                              GSignalFlags        signal_flags,
 291                                              guint               class_offset,
 292                                              GSignalAccumulator  accumulator,
 293                                              gpointer            accu_data,
 294                                              GSignalCMarshaller  c_marshaller,
 295                                              GType               return_type,
 296                                              guint               n_params,
 297                                              ...);
 298 GLIB_AVAILABLE_IN_ALL
 299 guint            g_signal_new_class_handler (const gchar        *signal_name,
 300                                              GType               itype,
 301                                              GSignalFlags        signal_flags,
 302                                              GCallback           class_handler,
 303                                              GSignalAccumulator  accumulator,
 304                                              gpointer            accu_data,
 305                                              GSignalCMarshaller  c_marshaller,
 306                                              GType               return_type,
 307                                              guint               n_params,
 308                                              ...);
 309 GLIB_AVAILABLE_IN_ALL
 310 void             g_signal_set_va_marshaller (guint              signal_id,
 311                                              GType              instance_type,
 312                                              GSignalCVaMarshaller va_marshaller);
 313
 314 GLIB_AVAILABLE_IN_ALL
 315 void                  g_signal_emitv        (const GValue       *instance_and_params,
 316                                              guint               signal_id,
 317                                              GQuark              detail,
 318                                              GValue             *return_value);
 319 GLIB_AVAILABLE_IN_ALL
 320 void                  g_signal_emit_valist  (gpointer            instance,
 321                                              guint               signal_id,
 322                                              GQuark              detail,
 323                                              va_list             var_args);
 324 GLIB_AVAILABLE_IN_ALL
 325 void                  g_signal_emit         (gpointer            instance,
 326                                              guint               signal_id,
 327                                              GQuark              detail,
 328                                              ...);
 329 GLIB_AVAILABLE_IN_ALL
 330 void                  g_signal_emit_by_name (gpointer            instance,
 331                                              const gchar        *detailed_signal,
 332                                              ...);
 333 GLIB_AVAILABLE_IN_ALL
 334 guint                 g_signal_lookup       (const gchar        *name,
 335                                              GType               itype);
 336 GLIB_AVAILABLE_IN_ALL
 337 const gchar *         g_signal_name         (guint               signal_id);
 338 GLIB_AVAILABLE_IN_ALL
 339 void                  g_signal_query        (guint               signal_id,
 340                                              GSignalQuery       *query);
 341 GLIB_AVAILABLE_IN_ALL
 342 guint*                g_signal_list_ids     (GType               itype,
 343                                              guint              *n_ids);
 344 GLIB_AVAILABLE_IN_ALL
 345 gboolean              g_signal_parse_name   (const gchar        *detailed_signal,
 346                                              GType               itype,
 347                                              guint              *signal_id_p,
 348                                              GQuark             *detail_p,
 349                                              gboolean            force_detail_quark);
 350 GLIB_AVAILABLE_IN_ALL
 351 GSignalInvocationHint* g_signal_get_invocation_hint (gpointer    instance);
 352
 353
 354 /* --- signal emissions --- */
 355 GLIB_AVAILABLE_IN_ALL
 356 void    g_signal_stop_emission              (gpointer             instance,
 357                                              guint                signal_id,
 358                                              GQuark               detail);
 359 GLIB_AVAILABLE_IN_ALL
 360 void    g_signal_stop_emission_by_name      (gpointer             instance,
 361                                              const gchar         *detailed_signal);
 362 GLIB_AVAILABLE_IN_ALL
 363 gulong  g_signal_add_emission_hook          (guint                signal_id,
 364                                              GQuark               detail,
 365                                              GSignalEmissionHook  hook_func,
 366                                              gpointer             hook_data,
 367                                              GDestroyNotify       data_destroy);
 368 GLIB_AVAILABLE_IN_ALL
 369 void    g_signal_remove_emission_hook       (guint                signal_id,
 370                                              gulong               hook_id);
 371
 372
 373 /* --- signal handlers --- */
 374 GLIB_AVAILABLE_IN_ALL
 375 gboolean g_signal_has_handler_pending         (gpointer           instance,
 376                                                guint              signal_id,
 377                                                GQuark             detail,
 378                                                gboolean           may_be_blocked);
 379 GLIB_AVAILABLE_IN_ALL
 380 gulong   g_signal_connect_closure_by_id       (gpointer           instance,
 381                                                guint              signal_id,
 382                                                GQuark             detail,
 383                                                GClosure          *closure,
 384                                                gboolean           after);
 385 GLIB_AVAILABLE_IN_ALL
 386 gulong   g_signal_connect_closure             (gpointer           instance,
 387                                                const gchar       *detailed_signal,
 388                                                GClosure          *closure,
 389                                                gboolean           after);
 390 GLIB_AVAILABLE_IN_ALL
 391 gulong   g_signal_connect_data                (gpointer           instance,
 392                                                const gchar       *detailed_signal,
 393                                                GCallback          c_handler,
 394                                                gpointer           data,
 395                                                GClosureNotify     destroy_data,
 396                                                GConnectFlags      connect_flags);
 397 GLIB_AVAILABLE_IN_ALL
 398 void     g_signal_handler_block               (gpointer           instance,
 399                                                gulong             handler_id);
 400 GLIB_AVAILABLE_IN_ALL
 401 void     g_signal_handler_unblock             (gpointer           instance,
 402                                                gulong             handler_id);
 403 GLIB_AVAILABLE_IN_ALL
 404 void     g_signal_handler_disconnect          (gpointer           instance,
 405                                                gulong             handler_id);
 406 GLIB_AVAILABLE_IN_ALL
 407 gboolean g_signal_handler_is_connected        (gpointer           instance,
 408                                                gulong             handler_id);
 409 GLIB_AVAILABLE_IN_ALL
 410 gulong   g_signal_handler_find                (gpointer           instance,
 411                                                GSignalMatchType   mask,
 412                                                guint              signal_id,
 413                                                GQuark             detail,
 414                                                GClosure          *closure,
 415                                                gpointer           func,
 416                                                gpointer           data);
 417 GLIB_AVAILABLE_IN_ALL
 418 guint    g_signal_handlers_block_matched      (gpointer           instance,
 419                                                GSignalMatchType   mask,
 420                                                guint              signal_id,
 421                                                GQuark             detail,
 422                                                GClosure          *closure,
 423                                                gpointer           func,
 424                                                gpointer           data);
 425 GLIB_AVAILABLE_IN_ALL
 426 guint    g_signal_handlers_unblock_matched    (gpointer           instance,
 427                                                GSignalMatchType   mask,
 428                                                guint              signal_id,
 429                                                GQuark             detail,
 430                                                GClosure          *closure,
 431                                                gpointer           func,
 432                                                gpointer           data);
 433 GLIB_AVAILABLE_IN_ALL
 434 guint    g_signal_handlers_disconnect_matched (gpointer           instance,
 435                                                GSignalMatchType   mask,
 436                                                guint              signal_id,
 437                                                GQuark             detail,
 438                                                GClosure          *closure,
 439                                                gpointer           func,
 440                                                gpointer           data);
 441
 442
 443 /* --- overriding and chaining --- */
 444 GLIB_AVAILABLE_IN_ALL
 445 void    g_signal_override_class_closure       (guint              signal_id,
 446                                                GType              instance_type,
 447                                                GClosure          *class_closure);
 448 GLIB_AVAILABLE_IN_ALL
 449 void    g_signal_override_class_handler       (const gchar       *signal_name,
 450                                                GType              instance_type,
 451                                                GCallback          class_handler);
 452 GLIB_AVAILABLE_IN_ALL
 453 void    g_signal_chain_from_overridden        (const GValue      *instance_and_params,
 454                                                GValue            *return_value);
 455 GLIB_AVAILABLE_IN_ALL
 456 void   g_signal_chain_from_overridden_handler (gpointer           instance,
 457                                                ...);
 458
 459
 460 /* --- convenience --- */
 461 /**
 462  * g_signal_connect:
 463  * @instance: the instance to connect to.
 464  * @detailed_signal: a string of the form "signal-name::detail".
 465  * @c_handler: the #GCallback to connect.
 466  * @data: data to pass to @c_handler calls.
 467  *
 468  * Connects a #GCallback function to a signal for a particular object.
 469  *
 470  * The handler will be called before the default handler of the signal.
 471  *
 472  * Returns: the handler id
 473  */
 474 #define g_signal_connect(instance, detailed_signal, c_handler, data) \
 475     g_signal_connect_data ((instance), (detailed_signal), (c_handler), (data), NULL, (GConnectFlags) 0)
 476 /**
 477  * g_signal_connect_after:
 478  * @instance: the instance to connect to.
 479  * @detailed_signal: a string of the form "signal-name::detail".
 480  * @c_handler: the #GCallback to connect.
 481  * @data: data to pass to @c_handler calls.
 482  *
 483  * Connects a #GCallback function to a signal for a particular object.
 484  *
 485  * The handler will be called after the default handler of the signal.
 486  *
 487  * Returns: the handler id
 488  */
 489 #define g_signal_connect_after(instance, detailed_signal, c_handler, data) \
 490     g_signal_connect_data ((instance), (detailed_signal), (c_handler), (data), NULL, G_CONNECT_AFTER)
 491 /**
 492  * g_signal_connect_swapped:
 493  * @instance: the instance to connect to.
 494  * @detailed_signal: a string of the form "signal-name::detail".
 495  * @c_handler: the #GCallback to connect.
 496  * @data: data to pass to @c_handler calls.
 497  *
 498  * Connects a #GCallback function to a signal for a particular object.
 499  *
 500  * The instance on which the signal is emitted and @data will be swapped when
 501  * calling the handler.
 502  *
 503  * Returns: the handler id
 504  */
 505 #define g_signal_connect_swapped(instance, detailed_signal, c_handler, data) \
 506     g_signal_connect_data ((instance), (detailed_signal), (c_handler), (data), NULL, G_CONNECT_SWAPPED)
 507 /**
 508  * g_signal_handlers_disconnect_by_func:
 509  * @instance: The instance to remove handlers from.
 510  * @func: The C closure callback of the handlers (useless for non-C closures).
 511  * @data: The closure data of the handlers' closures.
 512  *
 513  * Disconnects all handlers on an instance that match @func and @data.
 514  *
 515  * Returns: The number of handlers that matched.
 516  */
 517 #define g_signal_handlers_disconnect_by_func(instance, func, data)                                              \
 518     g_signal_handlers_disconnect_matched ((instance),                                                           \
 519                                           (GSignalMatchType) (G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA),       \
 520                                           0, 0, NULL, (func), (data))
 521
 522 /**
 523  * g_signal_handlers_disconnect_by_data:
 524  * @instance: The instance to remove handlers from
 525  * @data: the closure data of the handlers' closures
 526  *
 527  * Disconnects all handlers on an instance that match @data.
 528  *
 529  * Returns: The number of handlers that matched.
 530  *
 531  * Since: 2.32
 532  */
 533 #define g_signal_handlers_disconnect_by_data(instance, data) \
 534   g_signal_handlers_disconnect_matched ((instance), G_SIGNAL_MATCH_DATA, 0, 0, NULL, NULL, (data))
 535
 536 /**
 537  * g_signal_handlers_block_by_func:
 538  * @instance: The instance to block handlers from.
 539  * @func: The C closure callback of the handlers (useless for non-C closures).
 540  * @data: The closure data of the handlers' closures.
 541  *
 542  * Blocks all handlers on an instance that match @func and @data.
 543  *
 544  * Returns: The number of handlers that matched.
 545  */
 546 #define g_signal_handlers_block_by_func(instance, func, data)                                                   \
 547     g_signal_handlers_block_matched      ((instance),                                                           \
 548                                           (GSignalMatchType) (G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA),       \
 549                                           0, 0, NULL, (func), (data))
 550 /**
 551  * g_signal_handlers_unblock_by_func:
 552  * @instance: The instance to unblock handlers from.
 553  * @func: The C closure callback of the handlers (useless for non-C closures).
 554  * @data: The closure data of the handlers' closures.
 555  *
 556  * Unblocks all handlers on an instance that match @func and @data.
 557  *
 558  * Returns: The number of handlers that matched.
 559  */
 560 #define g_signal_handlers_unblock_by_func(instance, func, data)                                                 \
 561     g_signal_handlers_unblock_matched    ((instance),                                                           \
 562                                           (GSignalMatchType) (G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA),       \
 563                                           0, 0, NULL, (func), (data))
 564
 565
 566 GLIB_AVAILABLE_IN_ALL
 567 gboolean g_signal_accumulator_true_handled (GSignalInvocationHint *ihint,
 568                                             GValue                *return_accu,
 569                                             const GValue          *handler_return,
 570                                             gpointer               dummy);
 571
 572 GLIB_AVAILABLE_IN_ALL
 573 gboolean g_signal_accumulator_first_wins   (GSignalInvocationHint *ihint,
 574                                             GValue                *return_accu,
 575                                             const GValue          *handler_return,
 576                                             gpointer               dummy);
 577
 578 /*< private >*/
 579 GLIB_AVAILABLE_IN_ALL
 580 void     g_signal_handlers_destroy            (gpointer           instance);
 581 void     _g_signals_destroy                   (GType              itype);
 582
 583 G_END_DECLS
 584
 585 #endif /* __G_SIGNAL_H__ */