/* 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 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, write to the * Free Software Foundation, Inc., 59 Temple Place, Suite 330, * Boston, MA 02111-1307, USA. * * this code is based on the original GtkSignal implementation * for the Gtk+ library by Peter Mattis */ /* * MT safe */ #include "config.h" #include #include #include "gsignal.h" #include "gtype-private.h" #include "gbsearcharray.h" #include "gvaluecollector.h" #include "gvaluetypes.h" #include "gobject.h" #include "genums.h" #include "gobject_trace.h" /** * SECTION:signals * @short_description: A means for customization of object behaviour * and a general purpose notification mechanism * @title: Signals * * The basic concept of the signal system is that of the * emission of a signal. Signals are introduced * per-type and are identified through strings. Signals introduced * for a parent type are available in derived types as well, so * basically they are a per-type facility that is inherited. A signal * emission mainly involves invocation of a certain set of callbacks * in precisely defined manner. There are two main categories of such * callbacks, per-object * Although signals can deal with any kind of instantiatable * type, i'm referring to those types as "object types" in the following, * simply because that is the context most users will encounter signals in. * * ones and user provided ones. * The per-object callbacks are most often referred to as "object method * handler" or "default (signal) handler", while user provided callbacks are * usually just called "signal handler". * The object method handler is provided at signal creation time (this most * frequently happens at the end of an object class' creation), while user * provided handlers are frequently connected and disconnected to/from a certain * signal on certain object instances. * * A signal emission consists of five stages, unless prematurely stopped: * * * 1 - Invocation of the object method handler for %G_SIGNAL_RUN_FIRST signals * * * 2 - Invocation of normal user-provided signal handlers (after flag %FALSE) * * * 3 - Invocation of the object method handler for %G_SIGNAL_RUN_LAST signals * * * 4 - Invocation of user provided signal handlers, connected with an after flag of %TRUE * * * 5 - Invocation of the object method handler for %G_SIGNAL_RUN_CLEANUP signals * * * The user-provided signal handlers are called in the order they were * connected in. * All handlers may prematurely stop a signal emission, and any number of * handlers may be connected, disconnected, blocked or unblocked during * a signal emission. * There are certain criteria for skipping user handlers in stages 2 and 4 * of a signal emission. * First, user handlers may be blocked, blocked handlers are omitted * during callback invocation, to return from the "blocked" state, a * handler has to get unblocked exactly the same amount of times * it has been blocked before. * Second, upon emission of a %G_SIGNAL_DETAILED signal, an additional * "detail" argument passed in to g_signal_emit() has to match the detail * argument of the signal handler currently subject to invocation. * Specification of no detail argument for signal handlers (omission of the * detail part of the signal specification upon connection) serves as a * wildcard and matches any detail argument passed in to emission. */ #define REPORT_BUG "please report occurrence circumstances to gtk-devel-list@gnome.org" #ifdef G_ENABLE_DEBUG #define IF_DEBUG(debug_type, cond) if ((_g_type_debug_flags & G_TYPE_DEBUG_ ## debug_type) || cond) static volatile gpointer g_trace_instance_signals = NULL; static volatile gpointer g_trap_instance_signals = NULL; #endif /* G_ENABLE_DEBUG */ /* --- typedefs --- */ typedef struct _SignalNode SignalNode; typedef struct _SignalKey SignalKey; typedef struct _Emission Emission; typedef struct _Handler Handler; typedef struct _HandlerList HandlerList; typedef struct _HandlerMatch HandlerMatch; typedef enum { EMISSION_STOP, EMISSION_RUN, EMISSION_HOOK, EMISSION_RESTART } EmissionState; /* --- prototypes --- */ static inline guint signal_id_lookup (GQuark quark, GType itype); static void signal_destroy_R (SignalNode *signal_node); static inline HandlerList* handler_list_ensure (guint signal_id, gpointer instance); static inline HandlerList* handler_list_lookup (guint signal_id, gpointer instance); static inline Handler* handler_new (gboolean after); static void handler_insert (guint signal_id, gpointer instance, Handler *handler); static Handler* handler_lookup (gpointer instance, gulong handler_id, guint *signal_id_p); static inline HandlerMatch* handler_match_prepend (HandlerMatch *list, Handler *handler, guint signal_id); static inline HandlerMatch* handler_match_free1_R (HandlerMatch *node, gpointer instance); static HandlerMatch* handlers_find (gpointer instance, GSignalMatchType mask, guint signal_id, GQuark detail, GClosure *closure, gpointer func, gpointer data, gboolean one_and_only); static inline void handler_ref (Handler *handler); static inline void handler_unref_R (guint signal_id, gpointer instance, Handler *handler); static gint handler_lists_cmp (gconstpointer node1, gconstpointer node2); static inline void emission_push (Emission **emission_list_p, Emission *emission); static inline void emission_pop (Emission **emission_list_p, Emission *emission); static inline Emission* emission_find (Emission *emission_list, guint signal_id, GQuark detail, gpointer instance); static gint class_closures_cmp (gconstpointer node1, gconstpointer node2); static gint signal_key_cmp (gconstpointer node1, gconstpointer node2); static gboolean signal_emit_unlocked_R (SignalNode *node, GQuark detail, gpointer instance, GValue *return_value, const GValue *instance_and_params); static const gchar * type_debug_name (GType type); static void node_check_deprecated (const SignalNode *node); /* --- structures --- */ typedef struct { GSignalAccumulator func; gpointer data; } SignalAccumulator; typedef struct { GHook hook; GQuark detail; } SignalHook; #define SIGNAL_HOOK(hook) ((SignalHook*) (hook)) struct _SignalNode { /* permanent portion */ guint signal_id; GType itype; const gchar *name; guint destroyed : 1; /* reinitializable portion */ guint test_class_offset : 12; guint flags : 9; guint n_params : 8; GType *param_types; /* mangled with G_SIGNAL_TYPE_STATIC_SCOPE flag */ GType return_type; /* mangled with G_SIGNAL_TYPE_STATIC_SCOPE flag */ GBSearchArray *class_closure_bsa; SignalAccumulator *accumulator; GSignalCMarshaller c_marshaller; GHookList *emission_hooks; }; #define MAX_TEST_CLASS_OFFSET (4096) /* 2^12, 12 bits for test_class_offset */ #define TEST_CLASS_MAGIC (1) /* indicates NULL class closure, candidate for NOP optimization */ struct _SignalKey { GType itype; GQuark quark; guint signal_id; }; struct _Emission { Emission *next; gpointer instance; GSignalInvocationHint ihint; EmissionState state; GType chain_type; }; struct _HandlerList { guint signal_id; Handler *handlers; Handler *tail_before; /* normal signal handlers are appended here */ Handler *tail_after; /* CONNECT_AFTER handlers are appended here */ }; struct _Handler { gulong sequential_number; Handler *next; Handler *prev; GQuark detail; guint ref_count; guint block_count : 16; #define HANDLER_MAX_BLOCK_COUNT (1 << 16) guint after : 1; GClosure *closure; }; struct _HandlerMatch { Handler *handler; HandlerMatch *next; guint signal_id; }; typedef struct { GType instance_type; /* 0 for default closure */ GClosure *closure; } ClassClosure; /* --- variables --- */ static GBSearchArray *g_signal_key_bsa = NULL; static const GBSearchConfig g_signal_key_bconfig = { sizeof (SignalKey), signal_key_cmp, G_BSEARCH_ARRAY_ALIGN_POWER2, }; static GBSearchConfig g_signal_hlbsa_bconfig = { sizeof (HandlerList), handler_lists_cmp, 0, }; static GBSearchConfig g_class_closure_bconfig = { sizeof (ClassClosure), class_closures_cmp, 0, }; static GHashTable *g_handler_list_bsa_ht = NULL; static Emission *g_recursive_emissions = NULL; static Emission *g_restart_emissions = NULL; static gulong g_handler_sequential_number = 1; G_LOCK_DEFINE_STATIC (g_signal_mutex); #define SIGNAL_LOCK() G_LOCK (g_signal_mutex) #define SIGNAL_UNLOCK() G_UNLOCK (g_signal_mutex) /* --- signal nodes --- */ static guint g_n_signal_nodes = 0; static SignalNode **g_signal_nodes = NULL; static inline SignalNode* LOOKUP_SIGNAL_NODE (register guint signal_id) { if (signal_id < g_n_signal_nodes) return g_signal_nodes[signal_id]; else return NULL; } /* --- functions --- */ static inline guint signal_id_lookup (GQuark quark, GType itype) { GType *ifaces, type = itype; SignalKey key; guint n_ifaces; key.quark = quark; /* try looking up signals for this type and its ancestors */ do { SignalKey *signal_key; key.itype = type; signal_key = g_bsearch_array_lookup (g_signal_key_bsa, &g_signal_key_bconfig, &key); if (signal_key) return signal_key->signal_id; type = g_type_parent (type); } while (type); /* no luck, try interfaces it exports */ ifaces = g_type_interfaces (itype, &n_ifaces); while (n_ifaces--) { SignalKey *signal_key; key.itype = ifaces[n_ifaces]; signal_key = g_bsearch_array_lookup (g_signal_key_bsa, &g_signal_key_bconfig, &key); if (signal_key) { g_free (ifaces); return signal_key->signal_id; } } g_free (ifaces); return 0; } static gint class_closures_cmp (gconstpointer node1, gconstpointer node2) { const ClassClosure *c1 = node1, *c2 = node2; return G_BSEARCH_ARRAY_CMP (c1->instance_type, c2->instance_type); } static gint handler_lists_cmp (gconstpointer node1, gconstpointer node2) { const HandlerList *hlist1 = node1, *hlist2 = node2; return G_BSEARCH_ARRAY_CMP (hlist1->signal_id, hlist2->signal_id); } static inline HandlerList* handler_list_ensure (guint signal_id, gpointer instance) { GBSearchArray *hlbsa = g_hash_table_lookup (g_handler_list_bsa_ht, instance); HandlerList key; key.signal_id = signal_id; key.handlers = NULL; key.tail_before = NULL; key.tail_after = NULL; if (!hlbsa) { hlbsa = g_bsearch_array_create (&g_signal_hlbsa_bconfig); hlbsa = g_bsearch_array_insert (hlbsa, &g_signal_hlbsa_bconfig, &key); g_hash_table_insert (g_handler_list_bsa_ht, instance, hlbsa); } else { GBSearchArray *o = hlbsa; hlbsa = g_bsearch_array_insert (o, &g_signal_hlbsa_bconfig, &key); if (hlbsa != o) g_hash_table_insert (g_handler_list_bsa_ht, instance, hlbsa); } return g_bsearch_array_lookup (hlbsa, &g_signal_hlbsa_bconfig, &key); } static inline HandlerList* handler_list_lookup (guint signal_id, gpointer instance) { GBSearchArray *hlbsa = g_hash_table_lookup (g_handler_list_bsa_ht, instance); HandlerList key; key.signal_id = signal_id; return hlbsa ? g_bsearch_array_lookup (hlbsa, &g_signal_hlbsa_bconfig, &key) : NULL; } static Handler* handler_lookup (gpointer instance, gulong handler_id, guint *signal_id_p) { GBSearchArray *hlbsa = g_hash_table_lookup (g_handler_list_bsa_ht, instance); if (hlbsa) { guint i; for (i = 0; i < hlbsa->n_nodes; i++) { HandlerList *hlist = g_bsearch_array_get_nth (hlbsa, &g_signal_hlbsa_bconfig, i); Handler *handler; for (handler = hlist->handlers; handler; handler = handler->next) if (handler->sequential_number == handler_id) { if (signal_id_p) *signal_id_p = hlist->signal_id; return handler; } } } return NULL; } static inline HandlerMatch* handler_match_prepend (HandlerMatch *list, Handler *handler, guint signal_id) { HandlerMatch *node; node = g_slice_new (HandlerMatch); node->handler = handler; node->next = list; node->signal_id = signal_id; handler_ref (handler); return node; } static inline HandlerMatch* handler_match_free1_R (HandlerMatch *node, gpointer instance) { HandlerMatch *next = node->next; handler_unref_R (node->signal_id, instance, node->handler); g_slice_free (HandlerMatch, node); return next; } static HandlerMatch* handlers_find (gpointer instance, GSignalMatchType mask, guint signal_id, GQuark detail, GClosure *closure, gpointer func, gpointer data, gboolean one_and_only) { HandlerMatch *mlist = NULL; if (mask & G_SIGNAL_MATCH_ID) { HandlerList *hlist = handler_list_lookup (signal_id, instance); Handler *handler; SignalNode *node = NULL; if (mask & G_SIGNAL_MATCH_FUNC) { node = LOOKUP_SIGNAL_NODE (signal_id); if (!node || !node->c_marshaller) return NULL; } mask = ~mask; for (handler = hlist ? hlist->handlers : NULL; handler; handler = handler->next) if (handler->sequential_number && ((mask & G_SIGNAL_MATCH_DETAIL) || handler->detail == detail) && ((mask & G_SIGNAL_MATCH_CLOSURE) || handler->closure == closure) && ((mask & G_SIGNAL_MATCH_DATA) || handler->closure->data == data) && ((mask & G_SIGNAL_MATCH_UNBLOCKED) || handler->block_count == 0) && ((mask & G_SIGNAL_MATCH_FUNC) || (handler->closure->marshal == node->c_marshaller && handler->closure->meta_marshal == 0 && ((GCClosure*) handler->closure)->callback == func))) { mlist = handler_match_prepend (mlist, handler, signal_id); if (one_and_only) return mlist; } } else { GBSearchArray *hlbsa = g_hash_table_lookup (g_handler_list_bsa_ht, instance); mask = ~mask; if (hlbsa) { guint i; for (i = 0; i < hlbsa->n_nodes; i++) { HandlerList *hlist = g_bsearch_array_get_nth (hlbsa, &g_signal_hlbsa_bconfig, i); SignalNode *node = NULL; Handler *handler; if (!(mask & G_SIGNAL_MATCH_FUNC)) { node = LOOKUP_SIGNAL_NODE (hlist->signal_id); if (!node->c_marshaller) continue; } for (handler = hlist->handlers; handler; handler = handler->next) if (handler->sequential_number && ((mask & G_SIGNAL_MATCH_DETAIL) || handler->detail == detail) && ((mask & G_SIGNAL_MATCH_CLOSURE) || handler->closure == closure) && ((mask & G_SIGNAL_MATCH_DATA) || handler->closure->data == data) && ((mask & G_SIGNAL_MATCH_UNBLOCKED) || handler->block_count == 0) && ((mask & G_SIGNAL_MATCH_FUNC) || (handler->closure->marshal == node->c_marshaller && handler->closure->meta_marshal == 0 && ((GCClosure*) handler->closure)->callback == func))) { mlist = handler_match_prepend (mlist, handler, hlist->signal_id); if (one_and_only) return mlist; } } } } return mlist; } static inline Handler* handler_new (gboolean after) { Handler *handler = g_slice_new (Handler); #ifndef G_DISABLE_CHECKS if (g_handler_sequential_number < 1) g_error (G_STRLOC ": handler id overflow, %s", REPORT_BUG); #endif handler->sequential_number = g_handler_sequential_number++; handler->prev = NULL; handler->next = NULL; handler->detail = 0; handler->ref_count = 1; handler->block_count = 0; handler->after = after != FALSE; handler->closure = NULL; return handler; } static inline void handler_ref (Handler *handler) { g_return_if_fail (handler->ref_count > 0); g_atomic_int_inc ((int *)&handler->ref_count); } static inline void handler_unref_R (guint signal_id, gpointer instance, Handler *handler) { gboolean is_zero; g_return_if_fail (handler->ref_count > 0); is_zero = g_atomic_int_dec_and_test ((int *)&handler->ref_count); if (G_UNLIKELY (is_zero)) { HandlerList *hlist = NULL; if (handler->next) handler->next->prev = handler->prev; if (handler->prev) /* watch out for g_signal_handlers_destroy()! */ handler->prev->next = handler->next; else { hlist = handler_list_lookup (signal_id, instance); hlist->handlers = handler->next; } if (instance) { /* check if we are removing the handler pointed to by tail_before */ if (!handler->after && (!handler->next || handler->next->after)) { if (!hlist) hlist = handler_list_lookup (signal_id, instance); if (hlist) { g_assert (hlist->tail_before == handler); /* paranoid */ hlist->tail_before = handler->prev; } } /* check if we are removing the handler pointed to by tail_after */ if (!handler->next) { if (!hlist) hlist = handler_list_lookup (signal_id, instance); if (hlist) { g_assert (hlist->tail_after == handler); /* paranoid */ hlist->tail_after = handler->prev; } } } SIGNAL_UNLOCK (); g_closure_unref (handler->closure); SIGNAL_LOCK (); g_slice_free (Handler, handler); } } static void handler_insert (guint signal_id, gpointer instance, Handler *handler) { HandlerList *hlist; g_assert (handler->prev == NULL && handler->next == NULL); /* paranoid */ hlist = handler_list_ensure (signal_id, instance); if (!hlist->handlers) { hlist->handlers = handler; if (!handler->after) hlist->tail_before = handler; } else if (handler->after) { handler->prev = hlist->tail_after; hlist->tail_after->next = handler; } else { if (hlist->tail_before) { handler->next = hlist->tail_before->next; if (handler->next) handler->next->prev = handler; handler->prev = hlist->tail_before; hlist->tail_before->next = handler; } else /* insert !after handler into a list of only after handlers */ { handler->next = hlist->handlers; if (handler->next) handler->next->prev = handler; hlist->handlers = handler; } hlist->tail_before = handler; } if (!handler->next) hlist->tail_after = handler; } static inline void emission_push (Emission **emission_list_p, Emission *emission) { emission->next = *emission_list_p; *emission_list_p = emission; } static inline void emission_pop (Emission **emission_list_p, Emission *emission) { Emission *node, *last = NULL; for (node = *emission_list_p; node; last = node, node = last->next) if (node == emission) { if (last) last->next = node->next; else *emission_list_p = node->next; return; } g_assert_not_reached (); } static inline Emission* emission_find (Emission *emission_list, guint signal_id, GQuark detail, gpointer instance) { Emission *emission; for (emission = emission_list; emission; emission = emission->next) if (emission->instance == instance && emission->ihint.signal_id == signal_id && emission->ihint.detail == detail) return emission; return NULL; } static inline Emission* emission_find_innermost (gpointer instance) { Emission *emission, *s = NULL, *c = NULL; for (emission = g_restart_emissions; emission; emission = emission->next) if (emission->instance == instance) { s = emission; break; } for (emission = g_recursive_emissions; emission; emission = emission->next) if (emission->instance == instance) { c = emission; break; } if (!s) return c; else if (!c) return s; else return G_HAVE_GROWING_STACK ? MAX (c, s) : MIN (c, s); } static gint signal_key_cmp (gconstpointer node1, gconstpointer node2) { const SignalKey *key1 = node1, *key2 = node2; if (key1->itype == key2->itype) return G_BSEARCH_ARRAY_CMP (key1->quark, key2->quark); else return G_BSEARCH_ARRAY_CMP (key1->itype, key2->itype); } void _g_signal_init (void) { SIGNAL_LOCK (); if (!g_n_signal_nodes) { /* setup handler list binary searchable array hash table (in german, that'd be one word ;) */ g_handler_list_bsa_ht = g_hash_table_new (g_direct_hash, NULL); g_signal_key_bsa = g_bsearch_array_create (&g_signal_key_bconfig); /* invalid (0) signal_id */ g_n_signal_nodes = 1; g_signal_nodes = g_renew (SignalNode*, g_signal_nodes, g_n_signal_nodes); g_signal_nodes[0] = NULL; } SIGNAL_UNLOCK (); } void _g_signals_destroy (GType itype) { guint i; SIGNAL_LOCK (); for (i = 1; i < g_n_signal_nodes; i++) { SignalNode *node = g_signal_nodes[i]; if (node->itype == itype) { if (node->destroyed) g_warning (G_STRLOC ": signal \"%s\" of type `%s' already destroyed", node->name, type_debug_name (node->itype)); else signal_destroy_R (node); } } SIGNAL_UNLOCK (); } /** * g_signal_stop_emission: * @instance: the object whose signal handlers you wish to stop. * @signal_id: the signal identifier, as returned by g_signal_lookup(). * @detail: the detail which the signal was emitted with. * * Stops a signal's current emission. * * This will prevent the default method from running, if the signal was * %G_SIGNAL_RUN_LAST and you connected normally (i.e. without the "after" * flag). * * Prints a warning if used on a signal which isn't being emitted. */ void g_signal_stop_emission (gpointer instance, guint signal_id, GQuark detail) { SignalNode *node; g_return_if_fail (G_TYPE_CHECK_INSTANCE (instance)); g_return_if_fail (signal_id > 0); SIGNAL_LOCK (); node = LOOKUP_SIGNAL_NODE (signal_id); if (node && detail && !(node->flags & G_SIGNAL_DETAILED)) { g_warning ("%s: signal id `%u' does not support detail (%u)", G_STRLOC, signal_id, detail); SIGNAL_UNLOCK (); return; } if (node && g_type_is_a (G_TYPE_FROM_INSTANCE (instance), node->itype)) { Emission *emission_list = node->flags & G_SIGNAL_NO_RECURSE ? g_restart_emissions : g_recursive_emissions; Emission *emission = emission_find (emission_list, signal_id, detail, instance); if (emission) { if (emission->state == EMISSION_HOOK) g_warning (G_STRLOC ": emission of signal \"%s\" for instance `%p' cannot be stopped from emission hook", node->name, instance); else if (emission->state == EMISSION_RUN) emission->state = EMISSION_STOP; } else g_warning (G_STRLOC ": no emission of signal \"%s\" to stop for instance `%p'", node->name, instance); } else g_warning ("%s: signal id `%u' is invalid for instance `%p'", G_STRLOC, signal_id, instance); SIGNAL_UNLOCK (); } static void signal_finalize_hook (GHookList *hook_list, GHook *hook) { GDestroyNotify destroy = hook->destroy; if (destroy) { hook->destroy = NULL; SIGNAL_UNLOCK (); destroy (hook->data); SIGNAL_LOCK (); } } /** * g_signal_add_emission_hook: * @signal_id: the signal identifier, as returned by g_signal_lookup(). * @detail: the detail on which to call the hook. * @hook_func: a #GSignalEmissionHook function. * @hook_data: user data for @hook_func. * @data_destroy: a #GDestroyNotify for @hook_data. * * Adds an emission hook for a signal, which will get called for any emission * of that signal, independent of the instance. This is possible only * for signals which don't have #G_SIGNAL_NO_HOOKS flag set. * * Returns: the hook id, for later use with g_signal_remove_emission_hook(). */ gulong g_signal_add_emission_hook (guint signal_id, GQuark detail, GSignalEmissionHook hook_func, gpointer hook_data, GDestroyNotify data_destroy) { static gulong seq_hook_id = 1; SignalNode *node; GHook *hook; SignalHook *signal_hook; g_return_val_if_fail (signal_id > 0, 0); g_return_val_if_fail (hook_func != NULL, 0); SIGNAL_LOCK (); node = LOOKUP_SIGNAL_NODE (signal_id); if (!node || node->destroyed) { g_warning ("%s: invalid signal id `%u'", G_STRLOC, signal_id); SIGNAL_UNLOCK (); return 0; } if (node->flags & G_SIGNAL_NO_HOOKS) { g_warning ("%s: signal id `%u' does not support emission hooks (G_SIGNAL_NO_HOOKS flag set)", G_STRLOC, signal_id); SIGNAL_UNLOCK (); return 0; } if (detail && !(node->flags & G_SIGNAL_DETAILED)) { g_warning ("%s: signal id `%u' does not support detail (%u)", G_STRLOC, signal_id, detail); SIGNAL_UNLOCK (); return 0; } if (!node->emission_hooks) { node->emission_hooks = g_new (GHookList, 1); g_hook_list_init (node->emission_hooks, sizeof (SignalHook)); node->emission_hooks->finalize_hook = signal_finalize_hook; } node_check_deprecated (node); hook = g_hook_alloc (node->emission_hooks); hook->data = hook_data; hook->func = (gpointer) hook_func; hook->destroy = data_destroy; signal_hook = SIGNAL_HOOK (hook); signal_hook->detail = detail; node->emission_hooks->seq_id = seq_hook_id; g_hook_append (node->emission_hooks, hook); seq_hook_id = node->emission_hooks->seq_id; SIGNAL_UNLOCK (); return hook->hook_id; } /** * g_signal_remove_emission_hook: * @signal_id: the id of the signal * @hook_id: the id of the emission hook, as returned by * g_signal_add_emission_hook() * * Deletes an emission hook. */ void g_signal_remove_emission_hook (guint signal_id, gulong hook_id) { SignalNode *node; g_return_if_fail (signal_id > 0); g_return_if_fail (hook_id > 0); SIGNAL_LOCK (); node = LOOKUP_SIGNAL_NODE (signal_id); if (!node || node->destroyed) g_warning ("%s: invalid signal id `%u'", G_STRLOC, signal_id); else if (!node->emission_hooks || !g_hook_destroy (node->emission_hooks, hook_id)) g_warning ("%s: signal \"%s\" had no hook (%lu) to remove", G_STRLOC, node->name, hook_id); SIGNAL_UNLOCK (); } static inline guint signal_parse_name (const gchar *name, GType itype, GQuark *detail_p, gboolean force_quark) { const gchar *colon = strchr (name, ':'); guint signal_id; if (!colon) { signal_id = signal_id_lookup (g_quark_try_string (name), itype); if (signal_id && detail_p) *detail_p = 0; } else if (colon[1] == ':') { gchar buffer[32]; guint l = colon - name; if (l < 32) { memcpy (buffer, name, l); buffer[l] = 0; signal_id = signal_id_lookup (g_quark_try_string (buffer), itype); } else { gchar *signal = g_new (gchar, l + 1); memcpy (signal, name, l); signal[l] = 0; signal_id = signal_id_lookup (g_quark_try_string (signal), itype); g_free (signal); } if (signal_id && detail_p) *detail_p = colon[2] ? (force_quark ? g_quark_from_string : g_quark_try_string) (colon + 2) : 0; } else signal_id = 0; return signal_id; } /** * g_signal_parse_name: * @detailed_signal: a string of the form "signal-name::detail". * @itype: The interface/instance type that introduced "signal-name". * @signal_id_p: (out): Location to store the signal id. * @detail_p: (out): Location to store the detail quark. * @force_detail_quark: %TRUE forces creation of a #GQuark for the detail. * * Internal function to parse a signal name into its @signal_id * and @detail quark. * * Returns: Whether the signal name could successfully be parsed and @signal_id_p and @detail_p contain valid return values. */ gboolean g_signal_parse_name (const gchar *detailed_signal, GType itype, guint *signal_id_p, GQuark *detail_p, gboolean force_detail_quark) { SignalNode *node; GQuark detail = 0; guint signal_id; g_return_val_if_fail (detailed_signal != NULL, FALSE); g_return_val_if_fail (G_TYPE_IS_INSTANTIATABLE (itype) || G_TYPE_IS_INTERFACE (itype), FALSE); SIGNAL_LOCK (); signal_id = signal_parse_name (detailed_signal, itype, &detail, force_detail_quark); SIGNAL_UNLOCK (); node = signal_id ? LOOKUP_SIGNAL_NODE (signal_id) : NULL; if (!node || node->destroyed || (detail && !(node->flags & G_SIGNAL_DETAILED))) return FALSE; if (signal_id_p) *signal_id_p = signal_id; if (detail_p) *detail_p = detail; return TRUE; } /** * g_signal_stop_emission_by_name: * @instance: the object whose signal handlers you wish to stop. * @detailed_signal: a string of the form "signal-name::detail". * * Stops a signal's current emission. * * This is just like g_signal_stop_emission() except it will look up the * signal id for you. */ void g_signal_stop_emission_by_name (gpointer instance, const gchar *detailed_signal) { guint signal_id; GQuark detail = 0; GType itype; g_return_if_fail (G_TYPE_CHECK_INSTANCE (instance)); g_return_if_fail (detailed_signal != NULL); SIGNAL_LOCK (); itype = G_TYPE_FROM_INSTANCE (instance); signal_id = signal_parse_name (detailed_signal, itype, &detail, TRUE); if (signal_id) { SignalNode *node = LOOKUP_SIGNAL_NODE (signal_id); if (detail && !(node->flags & G_SIGNAL_DETAILED)) g_warning ("%s: signal `%s' does not support details", G_STRLOC, detailed_signal); else if (!g_type_is_a (itype, node->itype)) g_warning ("%s: signal `%s' is invalid for instance `%p'", G_STRLOC, detailed_signal, instance); else { Emission *emission_list = node->flags & G_SIGNAL_NO_RECURSE ? g_restart_emissions : g_recursive_emissions; Emission *emission = emission_find (emission_list, signal_id, detail, instance); if (emission) { if (emission->state == EMISSION_HOOK) g_warning (G_STRLOC ": emission of signal \"%s\" for instance `%p' cannot be stopped from emission hook", node->name, instance); else if (emission->state == EMISSION_RUN) emission->state = EMISSION_STOP; } else g_warning (G_STRLOC ": no emission of signal \"%s\" to stop for instance `%p'", node->name, instance); } } else g_warning ("%s: signal `%s' is invalid for instance `%p'", G_STRLOC, detailed_signal, instance); SIGNAL_UNLOCK (); } /** * g_signal_lookup: * @name: the signal's name. * @itype: the type that the signal operates on. * * Given the name of the signal and the type of object it connects to, gets * the signal's identifying integer. Emitting the signal by number is * somewhat faster than using the name each time. * * Also tries the ancestors of the given type. * * See g_signal_new() for details on allowed signal names. * * Returns: the signal's identifying number, or 0 if no signal was found. */ guint g_signal_lookup (const gchar *name, GType itype) { guint signal_id; g_return_val_if_fail (name != NULL, 0); g_return_val_if_fail (G_TYPE_IS_INSTANTIATABLE (itype) || G_TYPE_IS_INTERFACE (itype), 0); SIGNAL_LOCK (); signal_id = signal_id_lookup (g_quark_try_string (name), itype); SIGNAL_UNLOCK (); if (!signal_id) { /* give elaborate warnings */ if (!g_type_name (itype)) g_warning (G_STRLOC ": unable to lookup signal \"%s\" for invalid type id `%"G_GSIZE_FORMAT"'", name, itype); else if (!G_TYPE_IS_INSTANTIATABLE (itype)) g_warning (G_STRLOC ": unable to lookup signal \"%s\" for non instantiatable type `%s'", name, g_type_name (itype)); else if (!g_type_class_peek (itype)) g_warning (G_STRLOC ": unable to lookup signal \"%s\" of unloaded type `%s'", name, g_type_name (itype)); } return signal_id; } /** * g_signal_list_ids: * @itype: Instance or interface type. * @n_ids: Location to store the number of signal ids for @itype. * * Lists the signals by id that a certain instance or interface type * created. Further information about the signals can be acquired through * g_signal_query(). * * Returns: (array length=n_ids): Newly allocated array of signal IDs. */ guint* g_signal_list_ids (GType itype, guint *n_ids) { SignalKey *keys; GArray *result; guint n_nodes; guint i; g_return_val_if_fail (G_TYPE_IS_INSTANTIATABLE (itype) || G_TYPE_IS_INTERFACE (itype), NULL); g_return_val_if_fail (n_ids != NULL, NULL); SIGNAL_LOCK (); keys = g_bsearch_array_get_nth (g_signal_key_bsa, &g_signal_key_bconfig, 0); n_nodes = g_bsearch_array_get_n_nodes (g_signal_key_bsa); result = g_array_new (FALSE, FALSE, sizeof (guint)); for (i = 0; i < n_nodes; i++) if (keys[i].itype == itype) { const gchar *name = g_quark_to_string (keys[i].quark); /* Signal names with "_" in them are aliases to the same * name with "-" instead of "_". */ if (!strchr (name, '_')) g_array_append_val (result, keys[i].signal_id); } *n_ids = result->len; SIGNAL_UNLOCK (); if (!n_nodes) { /* give elaborate warnings */ if (!g_type_name (itype)) g_warning (G_STRLOC ": unable to list signals for invalid type id `%"G_GSIZE_FORMAT"'", itype); else if (!G_TYPE_IS_INSTANTIATABLE (itype) && !G_TYPE_IS_INTERFACE (itype)) g_warning (G_STRLOC ": unable to list signals of non instantiatable type `%s'", g_type_name (itype)); else if (!g_type_class_peek (itype) && !G_TYPE_IS_INTERFACE (itype)) g_warning (G_STRLOC ": unable to list signals of unloaded type `%s'", g_type_name (itype)); } return (guint*) g_array_free (result, FALSE); } /** * g_signal_name: * @signal_id: the signal's identifying number. * * Given the signal's identifier, finds its name. * * Two different signals may have the same name, if they have differing types. * * Returns: the signal name, or %NULL if the signal number was invalid. */ const gchar * g_signal_name (guint signal_id) { SignalNode *node; const gchar *name; SIGNAL_LOCK (); node = LOOKUP_SIGNAL_NODE (signal_id); name = node ? node->name : NULL; SIGNAL_UNLOCK (); return (char*) name; } /** * g_signal_query: * @signal_id: The signal id of the signal to query information for. * @query: (out caller-allocates): A user provided structure that is * filled in with constant values upon success. * * Queries the signal system for in-depth information about a * specific signal. This function will fill in a user-provided * structure to hold signal-specific information. If an invalid * signal id is passed in, the @signal_id member of the #GSignalQuery * is 0. All members filled into the #GSignalQuery structure should * be considered constant and have to be left untouched. */ void g_signal_query (guint signal_id, GSignalQuery *query) { SignalNode *node; g_return_if_fail (query != NULL); SIGNAL_LOCK (); node = LOOKUP_SIGNAL_NODE (signal_id); if (!node || node->destroyed) query->signal_id = 0; else { query->signal_id = node->signal_id; query->signal_name = node->name; query->itype = node->itype; query->signal_flags = node->flags; query->return_type = node->return_type; query->n_params = node->n_params; query->param_types = node->param_types; } SIGNAL_UNLOCK (); } /** * g_signal_new: * @signal_name: the name for the signal * @itype: the type this signal pertains to. It will also pertain to * types which are derived from this type. * @signal_flags: a combination of #GSignalFlags specifying detail of when * the default handler is to be invoked. You should at least specify * %G_SIGNAL_RUN_FIRST or %G_SIGNAL_RUN_LAST. * @class_offset: The offset of the function pointer in the class structure * for this type. Used to invoke a class method generically. Pass 0 to * not associate a class method slot with this signal. * @accumulator: the accumulator for this signal; may be %NULL. * @accu_data: user data for the @accumulator. * @c_marshaller: (allow-none): the function to translate arrays of parameter * values to signal emissions into C language callback invocations or %NULL. * @return_type: the type of return value, or #G_TYPE_NONE for a signal * without a return value. * @n_params: the number of parameter types to follow. * @...: a list of types, one for each parameter. * * Creates a new signal. (This is usually done in the class initializer.) * * A signal name consists of segments consisting of ASCII letters and * digits, separated by either the '-' or '_' character. The first * character of a signal name must be a letter. Names which violate these * rules lead to undefined behaviour of the GSignal system. * * When registering a signal and looking up a signal, either separator can * be used, but they cannot be mixed. * * If 0 is used for @class_offset subclasses cannot override the class handler * in their class_init method by doing * super_class->signal_handler = my_signal_handler. Instead they * will have to use g_signal_override_class_handler(). * * If c_marshaller is %NULL, g_cclosure_marshal_generic() will be used as * the marshaller for this signal. * * Returns: the signal id */ 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, ...) { va_list args; guint signal_id; g_return_val_if_fail (signal_name != NULL, 0); va_start (args, n_params); signal_id = g_signal_new_valist (signal_name, itype, signal_flags, class_offset ? g_signal_type_cclosure_new (itype, class_offset) : NULL, accumulator, accu_data, c_marshaller, return_type, n_params, args); va_end (args); /* optimize NOP emissions with NULL class handlers */ if (signal_id && G_TYPE_IS_INSTANTIATABLE (itype) && return_type == G_TYPE_NONE && class_offset && class_offset < MAX_TEST_CLASS_OFFSET && ~signal_flags & G_SIGNAL_MUST_COLLECT) { SignalNode *node; SIGNAL_LOCK (); node = LOOKUP_SIGNAL_NODE (signal_id); node->test_class_offset = class_offset; SIGNAL_UNLOCK (); } return signal_id; } /** * g_signal_new_class_handler: * @signal_name: the name for the signal * @itype: the type this signal pertains to. It will also pertain to * types which are derived from this type. * @signal_flags: a combination of #GSignalFlags specifying detail of when * the default handler is to be invoked. You should at least specify * %G_SIGNAL_RUN_FIRST or %G_SIGNAL_RUN_LAST. * @class_handler: a #GCallback which acts as class implementation of * this signal. Used to invoke a class method generically. Pass %NULL to * not associate a class method with this signal. * @accumulator: the accumulator for this signal; may be %NULL. * @accu_data: user data for the @accumulator. * @c_marshaller: (allow-none): the function to translate arrays of parameter * values to signal emissions into C language callback invocations or %NULL. * @return_type: the type of return value, or #G_TYPE_NONE for a signal * without a return value. * @n_params: the number of parameter types to follow. * @...: a list of types, one for each parameter. * * Creates a new signal. (This is usually done in the class initializer.) * * This is a variant of g_signal_new() that takes a C callback instead * off a class offset for the signal's class handler. This function * doesn't need a function pointer exposed in the class structure of * an object definition, instead the function pointer is passed * directly and can be overriden by derived classes with * g_signal_override_class_closure() or * g_signal_override_class_handler()and chained to with * g_signal_chain_from_overridden() or * g_signal_chain_from_overridden_handler(). * * See g_signal_new() for information about signal names. * * If c_marshaller is %NULL @g_cclosure_marshal_generic will be used as * the marshaller for this signal. * * Returns: the signal id * * Since: 2.18 */ 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, ...) { va_list args; guint signal_id; g_return_val_if_fail (signal_name != NULL, 0); va_start (args, n_params); signal_id = g_signal_new_valist (signal_name, itype, signal_flags, class_handler ? g_cclosure_new (class_handler, NULL, NULL) : NULL, accumulator, accu_data, c_marshaller, return_type, n_params, args); va_end (args); return signal_id; } static inline ClassClosure* signal_find_class_closure (SignalNode *node, GType itype) { GBSearchArray *bsa = node->class_closure_bsa; ClassClosure *cc; if (bsa) { ClassClosure key; /* cc->instance_type is 0 for default closure */ key.instance_type = itype; cc = g_bsearch_array_lookup (bsa, &g_class_closure_bconfig, &key); while (!cc && key.instance_type) { key.instance_type = g_type_parent (key.instance_type); cc = g_bsearch_array_lookup (bsa, &g_class_closure_bconfig, &key); } } else cc = NULL; return cc; } static inline GClosure* signal_lookup_closure (SignalNode *node, GTypeInstance *instance) { ClassClosure *cc; if (node->class_closure_bsa && g_bsearch_array_get_n_nodes (node->class_closure_bsa) == 1) { cc = g_bsearch_array_get_nth (node->class_closure_bsa, &g_class_closure_bconfig, 0); if (cc && cc->instance_type == 0) /* check for default closure */ return cc->closure; } cc = signal_find_class_closure (node, G_TYPE_FROM_INSTANCE (instance)); return cc ? cc->closure : NULL; } static void signal_add_class_closure (SignalNode *node, GType itype, GClosure *closure) { ClassClosure key; /* can't optimize NOP emissions with overridden class closures */ node->test_class_offset = 0; if (!node->class_closure_bsa) node->class_closure_bsa = g_bsearch_array_create (&g_class_closure_bconfig); key.instance_type = itype; key.closure = g_closure_ref (closure); node->class_closure_bsa = g_bsearch_array_insert (node->class_closure_bsa, &g_class_closure_bconfig, &key); g_closure_sink (closure); if (node->c_marshaller && closure && G_CLOSURE_NEEDS_MARSHAL (closure)) g_closure_set_marshal (closure, node->c_marshaller); } /** * g_signal_newv: * @signal_name: the name for the signal * @itype: the type this signal pertains to. It will also pertain to * types which are derived from this type * @signal_flags: a combination of #GSignalFlags specifying detail of when * the default handler is to be invoked. You should at least specify * %G_SIGNAL_RUN_FIRST or %G_SIGNAL_RUN_LAST * @class_closure: (allow-none): The closure to invoke on signal emission; * may be %NULL * @accumulator: (allow-none): the accumulator for this signal; may be %NULL * @accu_data: user data for the @accumulator * @c_marshaller: (allow-none): the function to translate arrays of * parameter values to signal emissions into C language callback * invocations or %NULL * @return_type: the type of return value, or #G_TYPE_NONE for a signal * without a return value * @n_params: the length of @param_types * @param_types: (array length=n_params): an array of types, one for * each parameter * * Creates a new signal. (This is usually done in the class initializer.) * * See g_signal_new() for details on allowed signal names. * * If c_marshaller is %NULL @g_cclosure_marshal_generic will be used as * the marshaller for this signal. * * Returns: the signal id */ 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) { gchar *name; guint signal_id, i; SignalNode *node; g_return_val_if_fail (signal_name != NULL, 0); g_return_val_if_fail (G_TYPE_IS_INSTANTIATABLE (itype) || G_TYPE_IS_INTERFACE (itype), 0); if (n_params) g_return_val_if_fail (param_types != NULL, 0); g_return_val_if_fail ((return_type & G_SIGNAL_TYPE_STATIC_SCOPE) == 0, 0); if (return_type == (G_TYPE_NONE & ~G_SIGNAL_TYPE_STATIC_SCOPE)) g_return_val_if_fail (accumulator == NULL, 0); if (!accumulator) g_return_val_if_fail (accu_data == NULL, 0); name = g_strdup (signal_name); g_strdelimit (name, G_STR_DELIMITERS ":^", '_'); /* FIXME do character checks like for types */ SIGNAL_LOCK (); signal_id = signal_id_lookup (g_quark_try_string (name), itype); node = LOOKUP_SIGNAL_NODE (signal_id); if (node && !node->destroyed) { g_warning (G_STRLOC ": signal \"%s\" already exists in the `%s' %s", name, type_debug_name (node->itype), G_TYPE_IS_INTERFACE (node->itype) ? "interface" : "class ancestry"); g_free (name); SIGNAL_UNLOCK (); return 0; } if (node && node->itype != itype) { g_warning (G_STRLOC ": signal \"%s\" for type `%s' was previously created for type `%s'", name, type_debug_name (itype), type_debug_name (node->itype)); g_free (name); SIGNAL_UNLOCK (); return 0; } for (i = 0; i < n_params; i++) if (!G_TYPE_IS_VALUE (param_types[i] & ~G_SIGNAL_TYPE_STATIC_SCOPE)) { g_warning (G_STRLOC ": parameter %d of type `%s' for signal \"%s::%s\" is not a value type", i + 1, type_debug_name (param_types[i]), type_debug_name (itype), name); g_free (name); SIGNAL_UNLOCK (); return 0; } if (return_type != G_TYPE_NONE && !G_TYPE_IS_VALUE (return_type & ~G_SIGNAL_TYPE_STATIC_SCOPE)) { g_warning (G_STRLOC ": return value of type `%s' for signal \"%s::%s\" is not a value type", type_debug_name (return_type), type_debug_name (itype), name); g_free (name); SIGNAL_UNLOCK (); return 0; } if (return_type != G_TYPE_NONE && (signal_flags & (G_SIGNAL_RUN_FIRST | G_SIGNAL_RUN_LAST | G_SIGNAL_RUN_CLEANUP)) == G_SIGNAL_RUN_FIRST) { g_warning (G_STRLOC ": signal \"%s::%s\" has return type `%s' and is only G_SIGNAL_RUN_FIRST", type_debug_name (itype), name, type_debug_name (return_type)); g_free (name); SIGNAL_UNLOCK (); return 0; } /* setup permanent portion of signal node */ if (!node) { SignalKey key; signal_id = g_n_signal_nodes++; node = g_new (SignalNode, 1); node->signal_id = signal_id; g_signal_nodes = g_renew (SignalNode*, g_signal_nodes, g_n_signal_nodes); g_signal_nodes[signal_id] = node; node->itype = itype; node->name = name; key.itype = itype; key.quark = g_quark_from_string (node->name); key.signal_id = signal_id; g_signal_key_bsa = g_bsearch_array_insert (g_signal_key_bsa, &g_signal_key_bconfig, &key); g_strdelimit (name, "_", '-'); node->name = g_intern_string (name); key.quark = g_quark_from_string (name); g_signal_key_bsa = g_bsearch_array_insert (g_signal_key_bsa, &g_signal_key_bconfig, &key); TRACE(GOBJECT_SIGNAL_NEW(signal_id, name, itype)); } node->destroyed = FALSE; node->test_class_offset = 0; /* setup reinitializable portion */ node->flags = signal_flags & G_SIGNAL_FLAGS_MASK; node->n_params = n_params; node->param_types = g_memdup (param_types, sizeof (GType) * n_params); node->return_type = return_type; node->class_closure_bsa = NULL; if (accumulator) { node->accumulator = g_new (SignalAccumulator, 1); node->accumulator->func = accumulator; node->accumulator->data = accu_data; } else node->accumulator = NULL; if (c_marshaller == NULL) c_marshaller = g_cclosure_marshal_generic; node->c_marshaller = c_marshaller; node->emission_hooks = NULL; if (class_closure) signal_add_class_closure (node, 0, class_closure); else if (G_TYPE_IS_INSTANTIATABLE (itype) && return_type == G_TYPE_NONE && ~signal_flags & G_SIGNAL_MUST_COLLECT) { /* optimize NOP emissions */ node->test_class_offset = TEST_CLASS_MAGIC; } SIGNAL_UNLOCK (); g_free (name); return signal_id; } /** * g_signal_new_valist: * @signal_name: the name for the signal * @itype: the type this signal pertains to. It will also pertain to * types which are derived from this type. * @signal_flags: a combination of #GSignalFlags specifying detail of when * the default handler is to be invoked. You should at least specify * %G_SIGNAL_RUN_FIRST or %G_SIGNAL_RUN_LAST. * @class_closure: The closure to invoke on signal emission; may be %NULL. * @accumulator: the accumulator for this signal; may be %NULL. * @accu_data: user data for the @accumulator. * @c_marshaller: (allow-none): the function to translate arrays of parameter * values to signal emissions into C language callback invocations or %NULL. * @return_type: the type of return value, or #G_TYPE_NONE for a signal * without a return value. * @n_params: the number of parameter types in @args. * @args: va_list of #GType, one for each parameter. * * Creates a new signal. (This is usually done in the class initializer.) * * See g_signal_new() for details on allowed signal names. * * If c_marshaller is %NULL, g_cclosure_marshal_generic() will be used as * the marshaller for this signal. * * Returns: the signal id */ 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) { GType *param_types; guint i; guint signal_id; if (n_params > 0) { param_types = g_new (GType, n_params); for (i = 0; i < n_params; i++) param_types[i] = va_arg (args, GType); } else param_types = NULL; signal_id = g_signal_newv (signal_name, itype, signal_flags, class_closure, accumulator, accu_data, c_marshaller, return_type, n_params, param_types); g_free (param_types); return signal_id; } static void signal_destroy_R (SignalNode *signal_node) { SignalNode node = *signal_node; signal_node->destroyed = TRUE; /* reentrancy caution, zero out real contents first */ signal_node->test_class_offset = 0; signal_node->n_params = 0; signal_node->param_types = NULL; signal_node->return_type = 0; signal_node->class_closure_bsa = NULL; signal_node->accumulator = NULL; signal_node->c_marshaller = NULL; signal_node->emission_hooks = NULL; #ifdef G_ENABLE_DEBUG /* check current emissions */ { Emission *emission; for (emission = (node.flags & G_SIGNAL_NO_RECURSE) ? g_restart_emissions : g_recursive_emissions; emission; emission = emission->next) if (emission->ihint.signal_id == node.signal_id) g_critical (G_STRLOC ": signal \"%s\" being destroyed is currently in emission (instance `%p')", node.name, emission->instance); } #endif /* free contents that need to */ SIGNAL_UNLOCK (); g_free (node.param_types); if (node.class_closure_bsa) { guint i; for (i = 0; i < node.class_closure_bsa->n_nodes; i++) { ClassClosure *cc = g_bsearch_array_get_nth (node.class_closure_bsa, &g_class_closure_bconfig, i); g_closure_unref (cc->closure); } g_bsearch_array_free (node.class_closure_bsa, &g_class_closure_bconfig); } g_free (node.accumulator); if (node.emission_hooks) { g_hook_list_clear (node.emission_hooks); g_free (node.emission_hooks); } SIGNAL_LOCK (); } /** * g_signal_override_class_closure: * @signal_id: the signal id * @instance_type: the instance type on which to override the class closure * for the signal. * @class_closure: the closure. * * Overrides the class closure (i.e. the default handler) for the given signal * for emissions on instances of @instance_type. @instance_type must be derived * from the type to which the signal belongs. * * See g_signal_chain_from_overridden() and * g_signal_chain_from_overridden_handler() for how to chain up to the * parent class closure from inside the overridden one. */ void g_signal_override_class_closure (guint signal_id, GType instance_type, GClosure *class_closure) { SignalNode *node; g_return_if_fail (signal_id > 0); g_return_if_fail (class_closure != NULL); SIGNAL_LOCK (); node = LOOKUP_SIGNAL_NODE (signal_id); node_check_deprecated (node); if (!g_type_is_a (instance_type, node->itype)) g_warning ("%s: type `%s' cannot be overridden for signal id `%u'", G_STRLOC, type_debug_name (instance_type), signal_id); else { ClassClosure *cc = signal_find_class_closure (node, instance_type); if (cc && cc->instance_type == instance_type) g_warning ("%s: type `%s' is already overridden for signal id `%u'", G_STRLOC, type_debug_name (instance_type), signal_id); else signal_add_class_closure (node, instance_type, class_closure); } SIGNAL_UNLOCK (); } /** * g_signal_override_class_handler: * @signal_name: the name for the signal * @instance_type: the instance type on which to override the class handler * for the signal. * @class_handler: the handler. * * Overrides the class closure (i.e. the default handler) for the * given signal for emissions on instances of @instance_type with * callabck @class_handler. @instance_type must be derived from the * type to which the signal belongs. * * See g_signal_chain_from_overridden() and * g_signal_chain_from_overridden_handler() for how to chain up to the * parent class closure from inside the overridden one. * * Since: 2.18 */ void g_signal_override_class_handler (const gchar *signal_name, GType instance_type, GCallback class_handler) { guint signal_id; g_return_if_fail (signal_name != NULL); g_return_if_fail (instance_type != G_TYPE_NONE); g_return_if_fail (class_handler != NULL); signal_id = g_signal_lookup (signal_name, instance_type); if (signal_id) g_signal_override_class_closure (signal_id, instance_type, g_cclosure_new (class_handler, NULL, NULL)); else g_warning ("%s: signal name '%s' is invalid for type id '%"G_GSIZE_FORMAT"'", G_STRLOC, signal_name, instance_type); } /** * g_signal_chain_from_overridden: * @instance_and_params: (array) the argument list of the signal emission. * The first element in the array is a #GValue for the instance the signal * is being emitted on. The rest are any arguments to be passed to the signal. * @return_value: Location for the return value. * * Calls the original class closure of a signal. This function should only * be called from an overridden class closure; see * g_signal_override_class_closure() and * g_signal_override_class_handler(). */ void g_signal_chain_from_overridden (const GValue *instance_and_params, GValue *return_value) { GType chain_type = 0, restore_type = 0; Emission *emission = NULL; GClosure *closure = NULL; guint n_params = 0; gpointer instance; g_return_if_fail (instance_and_params != NULL); instance = g_value_peek_pointer (instance_and_params); g_return_if_fail (G_TYPE_CHECK_INSTANCE (instance)); SIGNAL_LOCK (); emission = emission_find_innermost (instance); if (emission) { SignalNode *node = LOOKUP_SIGNAL_NODE (emission->ihint.signal_id); g_assert (node != NULL); /* paranoid */ /* we should probably do the same parameter checks as g_signal_emit() here. */ if (emission->chain_type != G_TYPE_NONE) { ClassClosure *cc = signal_find_class_closure (node, emission->chain_type); g_assert (cc != NULL); /* closure currently in call stack */ n_params = node->n_params; restore_type = cc->instance_type; cc = signal_find_class_closure (node, g_type_parent (cc->instance_type)); if (cc && cc->instance_type != restore_type) { closure = cc->closure; chain_type = cc->instance_type; } } else g_warning ("%s: signal id `%u' cannot be chained from current emission stage for instance `%p'", G_STRLOC, node->signal_id, instance); } else g_warning ("%s: no signal is currently being emitted for instance `%p'", G_STRLOC, instance); if (closure) { emission->chain_type = chain_type; SIGNAL_UNLOCK (); g_closure_invoke (closure, return_value, n_params + 1, instance_and_params, &emission->ihint); SIGNAL_LOCK (); emission->chain_type = restore_type; } SIGNAL_UNLOCK (); } /** * g_signal_chain_from_overridden_handler: * @instance: the instance the signal is being emitted on. * @...: parameters to be passed to the parent class closure, followed by a * location for the return value. If the return type of the signal * is #G_TYPE_NONE, the return value location can be omitted. * * Calls the original class closure of a signal. This function should * only be called from an overridden class closure; see * g_signal_override_class_closure() and * g_signal_override_class_handler(). * * Since: 2.18 */ void g_signal_chain_from_overridden_handler (gpointer instance, ...) { GType chain_type = 0, restore_type = 0; Emission *emission = NULL; GClosure *closure = NULL; SignalNode *node; guint n_params = 0; g_return_if_fail (G_TYPE_CHECK_INSTANCE (instance)); SIGNAL_LOCK (); emission = emission_find_innermost (instance); if (emission) { node = LOOKUP_SIGNAL_NODE (emission->ihint.signal_id); g_assert (node != NULL); /* paranoid */ /* we should probably do the same parameter checks as g_signal_emit() here. */ if (emission->chain_type != G_TYPE_NONE) { ClassClosure *cc = signal_find_class_closure (node, emission->chain_type); g_assert (cc != NULL); /* closure currently in call stack */ n_params = node->n_params; restore_type = cc->instance_type; cc = signal_find_class_closure (node, g_type_parent (cc->instance_type)); if (cc && cc->instance_type != restore_type) { closure = cc->closure; chain_type = cc->instance_type; } } else g_warning ("%s: signal id `%u' cannot be chained from current emission stage for instance `%p'", G_STRLOC, node->signal_id, instance); } else g_warning ("%s: no signal is currently being emitted for instance `%p'", G_STRLOC, instance); if (closure) { GValue *instance_and_params; GType signal_return_type; GValue *param_values; va_list var_args; guint i; va_start (var_args, instance); signal_return_type = node->return_type; instance_and_params = g_slice_alloc0 (sizeof (GValue) * (n_params + 1)); param_values = instance_and_params + 1; for (i = 0; i < node->n_params; i++) { gchar *error; GType ptype = node->param_types[i] & ~G_SIGNAL_TYPE_STATIC_SCOPE; gboolean static_scope = node->param_types[i] & G_SIGNAL_TYPE_STATIC_SCOPE; SIGNAL_UNLOCK (); G_VALUE_COLLECT_INIT (param_values + i, ptype, var_args, static_scope ? G_VALUE_NOCOPY_CONTENTS : 0, &error); if (error) { g_warning ("%s: %s", G_STRLOC, error); g_free (error); /* we purposely leak the value here, it might not be * in a sane state if an error condition occoured */ while (i--) g_value_unset (param_values + i); g_slice_free1 (sizeof (GValue) * (n_params + 1), instance_and_params); va_end (var_args); return; } SIGNAL_LOCK (); } SIGNAL_UNLOCK (); instance_and_params->g_type = 0; g_value_init (instance_and_params, G_TYPE_FROM_INSTANCE (instance)); g_value_set_instance (instance_and_params, instance); SIGNAL_LOCK (); emission->chain_type = chain_type; SIGNAL_UNLOCK (); if (signal_return_type == G_TYPE_NONE) { g_closure_invoke (closure, NULL, n_params + 1, instance_and_params, &emission->ihint); } else { GValue return_value = G_VALUE_INIT; gchar *error = NULL; GType rtype = signal_return_type & ~G_SIGNAL_TYPE_STATIC_SCOPE; gboolean static_scope = signal_return_type & G_SIGNAL_TYPE_STATIC_SCOPE; g_value_init (&return_value, rtype); g_closure_invoke (closure, &return_value, n_params + 1, instance_and_params, &emission->ihint); G_VALUE_LCOPY (&return_value, var_args, static_scope ? G_VALUE_NOCOPY_CONTENTS : 0, &error); if (!error) { g_value_unset (&return_value); } else { g_warning ("%s: %s", G_STRLOC, error); g_free (error); /* we purposely leak the value here, it might not be * in a sane state if an error condition occurred */ } } for (i = 0; i < n_params; i++) g_value_unset (param_values + i); g_value_unset (instance_and_params); g_slice_free1 (sizeof (GValue) * (n_params + 1), instance_and_params); va_end (var_args); SIGNAL_LOCK (); emission->chain_type = restore_type; } SIGNAL_UNLOCK (); } /** * g_signal_get_invocation_hint: * @instance: the instance to query * * Returns the invocation hint of the innermost signal emission of instance. * * Returns: (transfer none): the invocation hint of the innermost signal emission. */ GSignalInvocationHint* g_signal_get_invocation_hint (gpointer instance) { Emission *emission = NULL; g_return_val_if_fail (G_TYPE_CHECK_INSTANCE (instance), NULL); SIGNAL_LOCK (); emission = emission_find_innermost (instance); SIGNAL_UNLOCK (); return emission ? &emission->ihint : NULL; } /** * g_signal_connect_closure_by_id: * @instance: the instance to connect to. * @signal_id: the id of the signal. * @detail: the detail. * @closure: the closure to connect. * @after: whether the handler should be called before or after the * default handler of the signal. * * Connects a closure to a signal for a particular object. * * Returns: the handler id */ gulong g_signal_connect_closure_by_id (gpointer instance, guint signal_id, GQuark detail, GClosure *closure, gboolean after) { SignalNode *node; gulong handler_seq_no = 0; g_return_val_if_fail (G_TYPE_CHECK_INSTANCE (instance), 0); g_return_val_if_fail (signal_id > 0, 0); g_return_val_if_fail (closure != NULL, 0); SIGNAL_LOCK (); node = LOOKUP_SIGNAL_NODE (signal_id); if (node) { if (detail && !(node->flags & G_SIGNAL_DETAILED)) g_warning ("%s: signal id `%u' does not support detail (%u)", G_STRLOC, signal_id, detail); else if (!g_type_is_a (G_TYPE_FROM_INSTANCE (instance), node->itype)) g_warning ("%s: signal id `%u' is invalid for instance `%p'", G_STRLOC, signal_id, instance); else { Handler *handler = handler_new (after); handler_seq_no = handler->sequential_number; handler->detail = detail; handler->closure = g_closure_ref (closure); g_closure_sink (closure); handler_insert (signal_id, instance, handler); if (node->c_marshaller && G_CLOSURE_NEEDS_MARSHAL (closure)) g_closure_set_marshal (closure, node->c_marshaller); } } else g_warning ("%s: signal id `%u' is invalid for instance `%p'", G_STRLOC, signal_id, instance); SIGNAL_UNLOCK (); return handler_seq_no; } /** * g_signal_connect_closure: * @instance: the instance to connect to. * @detailed_signal: a string of the form "signal-name::detail". * @closure: the closure to connect. * @after: whether the handler should be called before or after the * default handler of the signal. * * Connects a closure to a signal for a particular object. * * Returns: the handler id */ gulong g_signal_connect_closure (gpointer instance, const gchar *detailed_signal, GClosure *closure, gboolean after) { guint signal_id; gulong handler_seq_no = 0; GQuark detail = 0; GType itype; g_return_val_if_fail (G_TYPE_CHECK_INSTANCE (instance), 0); g_return_val_if_fail (detailed_signal != NULL, 0); g_return_val_if_fail (closure != NULL, 0); SIGNAL_LOCK (); itype = G_TYPE_FROM_INSTANCE (instance); signal_id = signal_parse_name (detailed_signal, itype, &detail, TRUE); if (signal_id) { SignalNode *node = LOOKUP_SIGNAL_NODE (signal_id); if (detail && !(node->flags & G_SIGNAL_DETAILED)) g_warning ("%s: signal `%s' does not support details", G_STRLOC, detailed_signal); else if (!g_type_is_a (itype, node->itype)) g_warning ("%s: signal `%s' is invalid for instance `%p'", G_STRLOC, detailed_signal, instance); else { Handler *handler = handler_new (after); handler_seq_no = handler->sequential_number; handler->detail = detail; handler->closure = g_closure_ref (closure); g_closure_sink (closure); handler_insert (signal_id, instance, handler); if (node->c_marshaller && G_CLOSURE_NEEDS_MARSHAL (handler->closure)) g_closure_set_marshal (handler->closure, node->c_marshaller); } } else g_warning ("%s: signal `%s' is invalid for instance `%p'", G_STRLOC, detailed_signal, instance); SIGNAL_UNLOCK (); return handler_seq_no; } static void node_check_deprecated (const SignalNode *node) { static const gchar * g_enable_diagnostic = NULL; if (G_UNLIKELY (!g_enable_diagnostic)) { g_enable_diagnostic = g_getenv ("G_ENABLE_DIAGNOSTIC"); if (!g_enable_diagnostic) g_enable_diagnostic = "0"; } if (g_enable_diagnostic[0] == '1') { if (node->flags & G_SIGNAL_DEPRECATED) { g_warning ("The signal %s::%s is deprecated and shouldn't be used " "anymore. It will be removed in a future version.", type_debug_name (node->itype), node->name); } } } /** * g_signal_connect_data: * @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. * @destroy_data: a #GClosureNotify for @data. * @connect_flags: a combination of #GConnectFlags. * * Connects a #GCallback function to a signal for a particular object. Similar * to g_signal_connect(), but allows to provide a #GClosureNotify for the data * which will be called when the signal handler is disconnected and no longer * used. Specify @connect_flags if you need ..._after() or * ..._swapped() variants of this function. * * Returns: the handler id */ gulong g_signal_connect_data (gpointer instance, const gchar *detailed_signal, GCallback c_handler, gpointer data, GClosureNotify destroy_data, GConnectFlags connect_flags) { guint signal_id; gulong handler_seq_no = 0; GQuark detail = 0; GType itype; gboolean swapped, after; g_return_val_if_fail (G_TYPE_CHECK_INSTANCE (instance), 0); g_return_val_if_fail (detailed_signal != NULL, 0); g_return_val_if_fail (c_handler != NULL, 0); swapped = (connect_flags & G_CONNECT_SWAPPED) != FALSE; after = (connect_flags & G_CONNECT_AFTER) != FALSE; SIGNAL_LOCK (); itype = G_TYPE_FROM_INSTANCE (instance); signal_id = signal_parse_name (detailed_signal, itype, &detail, TRUE); if (signal_id) { SignalNode *node = LOOKUP_SIGNAL_NODE (signal_id); node_check_deprecated (node); if (detail && !(node->flags & G_SIGNAL_DETAILED)) g_warning ("%s: signal `%s' does not support details", G_STRLOC, detailed_signal); else if (!g_type_is_a (itype, node->itype)) g_warning ("%s: signal `%s' is invalid for instance `%p'", G_STRLOC, detailed_signal, instance); else { Handler *handler = handler_new (after); handler_seq_no = handler->sequential_number; handler->detail = detail; handler->closure = g_closure_ref ((swapped ? g_cclosure_new_swap : g_cclosure_new) (c_handler, data, destroy_data)); g_closure_sink (handler->closure); handler_insert (signal_id, instance, handler); if (node->c_marshaller && G_CLOSURE_NEEDS_MARSHAL (handler->closure)) g_closure_set_marshal (handler->closure, node->c_marshaller); } } else g_warning ("%s: signal `%s' is invalid for instance `%p'", G_STRLOC, detailed_signal, instance); SIGNAL_UNLOCK (); return handler_seq_no; } /** * g_signal_handler_block: * @instance: The instance to block the signal handler of. * @handler_id: Handler id of the handler to be blocked. * * Blocks a handler of an instance so it will not be called during any * signal emissions unless it is unblocked again. Thus "blocking" a * signal handler means to temporarily deactive it, a signal handler * has to be unblocked exactly the same amount of times it has been * blocked before to become active again. * * The @handler_id has to be a valid signal handler id, connected to a * signal of @instance. */ void g_signal_handler_block (gpointer instance, gulong handler_id) { Handler *handler; g_return_if_fail (G_TYPE_CHECK_INSTANCE (instance)); g_return_if_fail (handler_id > 0); SIGNAL_LOCK (); handler = handler_lookup (instance, handler_id, NULL); if (handler) { #ifndef G_DISABLE_CHECKS if (handler->block_count >= HANDLER_MAX_BLOCK_COUNT - 1) g_error (G_STRLOC ": handler block_count overflow, %s", REPORT_BUG); #endif handler->block_count += 1; } else g_warning ("%s: instance `%p' has no handler with id `%lu'", G_STRLOC, instance, handler_id); SIGNAL_UNLOCK (); } /** * g_signal_handler_unblock: * @instance: The instance to unblock the signal handler of. * @handler_id: Handler id of the handler to be unblocked. * * Undoes the effect of a previous g_signal_handler_block() call. A * blocked handler is skipped during signal emissions and will not be * invoked, unblocking it (for exactly the amount of times it has been * blocked before) reverts its "blocked" state, so the handler will be * recognized by the signal system and is called upon future or * currently ongoing signal emissions (since the order in which * handlers are called during signal emissions is deterministic, * whether the unblocked handler in question is called as part of a * currently ongoing emission depends on how far that emission has * proceeded yet). * * The @handler_id has to be a valid id of a signal handler that is * connected to a signal of @instance and is currently blocked. */ void g_signal_handler_unblock (gpointer instance, gulong handler_id) { Handler *handler; g_return_if_fail (G_TYPE_CHECK_INSTANCE (instance)); g_return_if_fail (handler_id > 0); SIGNAL_LOCK (); handler = handler_lookup (instance, handler_id, NULL); if (handler) { if (handler->block_count) handler->block_count -= 1; else g_warning (G_STRLOC ": handler `%lu' of instance `%p' is not blocked", handler_id, instance); } else g_warning ("%s: instance `%p' has no handler with id `%lu'", G_STRLOC, instance, handler_id); SIGNAL_UNLOCK (); } /** * g_signal_handler_disconnect: * @instance: The instance to remove the signal handler from. * @handler_id: Handler id of the handler to be disconnected. * * Disconnects a handler from an instance so it will not be called during * any future or currently ongoing emissions of the signal it has been * connected to. The @handler_id becomes invalid and may be reused. * * The @handler_id has to be a valid signal handler id, connected to a * signal of @instance. */ void g_signal_handler_disconnect (gpointer instance, gulong handler_id) { Handler *handler; guint signal_id; g_return_if_fail (G_TYPE_CHECK_INSTANCE (instance)); g_return_if_fail (handler_id > 0); SIGNAL_LOCK (); handler = handler_lookup (instance, handler_id, &signal_id); if (handler) { handler->sequential_number = 0; handler->block_count = 1; handler_unref_R (signal_id, instance, handler); } else g_warning ("%s: instance `%p' has no handler with id `%lu'", G_STRLOC, instance, handler_id); SIGNAL_UNLOCK (); } /** * g_signal_handler_is_connected: * @instance: The instance where a signal handler is sought. * @handler_id: the handler id. * * Returns whether @handler_id is the id of a handler connected to @instance. * * Returns: whether @handler_id identifies a handler connected to @instance. */ gboolean g_signal_handler_is_connected (gpointer instance, gulong handler_id) { Handler *handler; gboolean connected; g_return_val_if_fail (G_TYPE_CHECK_INSTANCE (instance), FALSE); SIGNAL_LOCK (); handler = handler_lookup (instance, handler_id, NULL); connected = handler != NULL; SIGNAL_UNLOCK (); return connected; } void g_signal_handlers_destroy (gpointer instance) { GBSearchArray *hlbsa; g_return_if_fail (G_TYPE_CHECK_INSTANCE (instance)); SIGNAL_LOCK (); hlbsa = g_hash_table_lookup (g_handler_list_bsa_ht, instance); if (hlbsa) { guint i; /* reentrancy caution, delete instance trace first */ g_hash_table_remove (g_handler_list_bsa_ht, instance); for (i = 0; i < hlbsa->n_nodes; i++) { HandlerList *hlist = g_bsearch_array_get_nth (hlbsa, &g_signal_hlbsa_bconfig, i); Handler *handler = hlist->handlers; while (handler) { Handler *tmp = handler; handler = tmp->next; tmp->block_count = 1; /* cruel unlink, this works because _all_ handlers vanish */ tmp->next = NULL; tmp->prev = tmp; if (tmp->sequential_number) { tmp->sequential_number = 0; handler_unref_R (0, NULL, tmp); } } } g_bsearch_array_free (hlbsa, &g_signal_hlbsa_bconfig); } SIGNAL_UNLOCK (); } /** * g_signal_handler_find: * @instance: The instance owning the signal handler to be found. * @mask: Mask indicating which of @signal_id, @detail, @closure, @func * and/or @data the handler has to match. * @signal_id: Signal the handler has to be connected to. * @detail: Signal detail the handler has to be connected to. * @closure: (allow-none): The closure the handler will invoke. * @func: The C closure callback of the handler (useless for non-C closures). * @data: The closure data of the handler's closure. * * Finds the first signal handler that matches certain selection criteria. * The criteria mask is passed as an OR-ed combination of #GSignalMatchType * flags, and the criteria values are passed as arguments. * The match @mask has to be non-0 for successful matches. * If no handler was found, 0 is returned. * * Returns: A valid non-0 signal handler id for a successful match. */ gulong g_signal_handler_find (gpointer instance, GSignalMatchType mask, guint signal_id, GQuark detail, GClosure *closure, gpointer func, gpointer data) { gulong handler_seq_no = 0; g_return_val_if_fail (G_TYPE_CHECK_INSTANCE (instance), 0); g_return_val_if_fail ((mask & ~G_SIGNAL_MATCH_MASK) == 0, 0); if (mask & G_SIGNAL_MATCH_MASK) { HandlerMatch *mlist; SIGNAL_LOCK (); mlist = handlers_find (instance, mask, signal_id, detail, closure, func, data, TRUE); if (mlist) { handler_seq_no = mlist->handler->sequential_number; handler_match_free1_R (mlist, instance); } SIGNAL_UNLOCK (); } return handler_seq_no; } static guint signal_handlers_foreach_matched_R (gpointer instance, GSignalMatchType mask, guint signal_id, GQuark detail, GClosure *closure, gpointer func, gpointer data, void (*callback) (gpointer instance, gulong handler_seq_no)) { HandlerMatch *mlist; guint n_handlers = 0; mlist = handlers_find (instance, mask, signal_id, detail, closure, func, data, FALSE); while (mlist) { n_handlers++; if (mlist->handler->sequential_number) { SIGNAL_UNLOCK (); callback (instance, mlist->handler->sequential_number); SIGNAL_LOCK (); } mlist = handler_match_free1_R (mlist, instance); } return n_handlers; } /** * g_signal_handlers_block_matched: * @instance: The instance to block handlers from. * @mask: Mask indicating which of @signal_id, @detail, @closure, @func * and/or @data the handlers have to match. * @signal_id: Signal the handlers have to be connected to. * @detail: Signal detail the handlers have to be connected to. * @closure: (allow-none): The closure the handlers will invoke. * @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 a certain selection criteria. * The criteria mask is passed as an OR-ed combination of #GSignalMatchType * flags, and the criteria values are passed as arguments. * Passing at least one of the %G_SIGNAL_MATCH_CLOSURE, %G_SIGNAL_MATCH_FUNC * or %G_SIGNAL_MATCH_DATA match flags is required for successful matches. * If no handlers were found, 0 is returned, the number of blocked handlers * otherwise. * * Returns: The number of handlers that matched. */ guint g_signal_handlers_block_matched (gpointer instance, GSignalMatchType mask, guint signal_id, GQuark detail, GClosure *closure, gpointer func, gpointer data) { guint n_handlers = 0; g_return_val_if_fail (G_TYPE_CHECK_INSTANCE (instance), 0); g_return_val_if_fail ((mask & ~G_SIGNAL_MATCH_MASK) == 0, 0); if (mask & (G_SIGNAL_MATCH_CLOSURE | G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA)) { SIGNAL_LOCK (); n_handlers = signal_handlers_foreach_matched_R (instance, mask, signal_id, detail, closure, func, data, g_signal_handler_block); SIGNAL_UNLOCK (); } return n_handlers; } /** * g_signal_handlers_unblock_matched: * @instance: The instance to unblock handlers from. * @mask: Mask indicating which of @signal_id, @detail, @closure, @func * and/or @data the handlers have to match. * @signal_id: Signal the handlers have to be connected to. * @detail: Signal detail the handlers have to be connected to. * @closure: (allow-none): The closure the handlers will invoke. * @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 a certain selection * criteria. The criteria mask is passed as an OR-ed combination of * #GSignalMatchType flags, and the criteria values are passed as arguments. * Passing at least one of the %G_SIGNAL_MATCH_CLOSURE, %G_SIGNAL_MATCH_FUNC * or %G_SIGNAL_MATCH_DATA match flags is required for successful matches. * If no handlers were found, 0 is returned, the number of unblocked handlers * otherwise. The match criteria should not apply to any handlers that are * not currently blocked. * * Returns: The number of handlers that matched. */ guint g_signal_handlers_unblock_matched (gpointer instance, GSignalMatchType mask, guint signal_id, GQuark detail, GClosure *closure, gpointer func, gpointer data) { guint n_handlers = 0; g_return_val_if_fail (G_TYPE_CHECK_INSTANCE (instance), 0); g_return_val_if_fail ((mask & ~G_SIGNAL_MATCH_MASK) == 0, 0); if (mask & (G_SIGNAL_MATCH_CLOSURE | G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA)) { SIGNAL_LOCK (); n_handlers = signal_handlers_foreach_matched_R (instance, mask, signal_id, detail, closure, func, data, g_signal_handler_unblock); SIGNAL_UNLOCK (); } return n_handlers; } /** * g_signal_handlers_disconnect_matched: * @instance: The instance to remove handlers from. * @mask: Mask indicating which of @signal_id, @detail, @closure, @func * and/or @data the handlers have to match. * @signal_id: Signal the handlers have to be connected to. * @detail: Signal detail the handlers have to be connected to. * @closure: (allow-none): The closure the handlers will invoke. * @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 a certain * selection criteria. The criteria mask is passed as an OR-ed * combination of #GSignalMatchType flags, and the criteria values are * passed as arguments. Passing at least one of the * %G_SIGNAL_MATCH_CLOSURE, %G_SIGNAL_MATCH_FUNC or * %G_SIGNAL_MATCH_DATA match flags is required for successful * matches. If no handlers were found, 0 is returned, the number of * disconnected handlers otherwise. * * Returns: The number of handlers that matched. */ guint g_signal_handlers_disconnect_matched (gpointer instance, GSignalMatchType mask, guint signal_id, GQuark detail, GClosure *closure, gpointer func, gpointer data) { guint n_handlers = 0; g_return_val_if_fail (G_TYPE_CHECK_INSTANCE (instance), 0); g_return_val_if_fail ((mask & ~G_SIGNAL_MATCH_MASK) == 0, 0); if (mask & (G_SIGNAL_MATCH_CLOSURE | G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA)) { SIGNAL_LOCK (); n_handlers = signal_handlers_foreach_matched_R (instance, mask, signal_id, detail, closure, func, data, g_signal_handler_disconnect); SIGNAL_UNLOCK (); } return n_handlers; } /** * g_signal_has_handler_pending: * @instance: the object whose signal handlers are sought. * @signal_id: the signal id. * @detail: the detail. * @may_be_blocked: whether blocked handlers should count as match. * * Returns whether there are any handlers connected to @instance for the * given signal id and detail. * * One example of when you might use this is when the arguments to the * signal are difficult to compute. A class implementor may opt to not * emit the signal if no one is attached anyway, thus saving the cost * of building the arguments. * * Returns: %TRUE if a handler is connected to the signal, %FALSE * otherwise. */ gboolean g_signal_has_handler_pending (gpointer instance, guint signal_id, GQuark detail, gboolean may_be_blocked) { HandlerMatch *mlist; gboolean has_pending; g_return_val_if_fail (G_TYPE_CHECK_INSTANCE (instance), FALSE); g_return_val_if_fail (signal_id > 0, FALSE); SIGNAL_LOCK (); if (detail) { SignalNode *node = LOOKUP_SIGNAL_NODE (signal_id); if (!(node->flags & G_SIGNAL_DETAILED)) { g_warning ("%s: signal id `%u' does not support detail (%u)", G_STRLOC, signal_id, detail); SIGNAL_UNLOCK (); return FALSE; } } mlist = handlers_find (instance, (G_SIGNAL_MATCH_ID | G_SIGNAL_MATCH_DETAIL | (may_be_blocked ? 0 : G_SIGNAL_MATCH_UNBLOCKED)), signal_id, detail, NULL, NULL, NULL, TRUE); if (mlist) { has_pending = TRUE; handler_match_free1_R (mlist, instance); } else has_pending = FALSE; SIGNAL_UNLOCK (); return has_pending; } static inline gboolean signal_check_skip_emission (SignalNode *node, gpointer instance, GQuark detail) { HandlerList *hlist; /* are we able to check for NULL class handlers? */ if (!node->test_class_offset) return FALSE; /* are there emission hooks pending? */ if (node->emission_hooks && node->emission_hooks->hooks) return FALSE; /* is there a non-NULL class handler? */ if (node->test_class_offset != TEST_CLASS_MAGIC) { GTypeClass *class = G_TYPE_INSTANCE_GET_CLASS (instance, G_TYPE_FROM_INSTANCE (instance), GTypeClass); if (G_STRUCT_MEMBER (gpointer, class, node->test_class_offset)) return FALSE; } /* are signals being debugged? */ #ifdef G_ENABLE_DEBUG IF_DEBUG (SIGNALS, g_trace_instance_signals || g_trap_instance_signals) return FALSE; #endif /* G_ENABLE_DEBUG */ /* is this a no-recurse signal already in emission? */ if (node->flags & G_SIGNAL_NO_RECURSE && emission_find (g_restart_emissions, node->signal_id, detail, instance)) return FALSE; /* do we have pending handlers? */ hlist = handler_list_lookup (node->signal_id, instance); if (hlist && hlist->handlers) return FALSE; /* none of the above, no emission required */ return TRUE; } /** * g_signal_emitv: * @instance_and_params: (array): argument list for the signal emission. * The first element in the array is a #GValue for the instance the signal * is being emitted on. The rest are any arguments to be passed to the signal. * @signal_id: the signal id * @detail: the detail * @return_value: Location to store the return value of the signal emission. * * Emits a signal. * * Note that g_signal_emitv() doesn't change @return_value if no handlers are * connected, in contrast to g_signal_emit() and g_signal_emit_valist(). */ void g_signal_emitv (const GValue *instance_and_params, guint signal_id, GQuark detail, GValue *return_value) { gpointer instance; SignalNode *node; #ifdef G_ENABLE_DEBUG const GValue *param_values; guint i; #endif g_return_if_fail (instance_and_params != NULL); instance = g_value_peek_pointer (instance_and_params); g_return_if_fail (G_TYPE_CHECK_INSTANCE (instance)); g_return_if_fail (signal_id > 0); #ifdef G_ENABLE_DEBUG param_values = instance_and_params + 1; #endif SIGNAL_LOCK (); node = LOOKUP_SIGNAL_NODE (signal_id); if (!node || !g_type_is_a (G_TYPE_FROM_INSTANCE (instance), node->itype)) { g_warning ("%s: signal id `%u' is invalid for instance `%p'", G_STRLOC, signal_id, instance); SIGNAL_UNLOCK (); return; } #ifdef G_ENABLE_DEBUG if (detail && !(node->flags & G_SIGNAL_DETAILED)) { g_warning ("%s: signal id `%u' does not support detail (%u)", G_STRLOC, signal_id, detail); SIGNAL_UNLOCK (); return; } for (i = 0; i < node->n_params; i++) if (!G_TYPE_CHECK_VALUE_TYPE (param_values + i, node->param_types[i] & ~G_SIGNAL_TYPE_STATIC_SCOPE)) { g_critical ("%s: value for `%s' parameter %u for signal \"%s\" is of type `%s'", G_STRLOC, type_debug_name (node->param_types[i]), i, node->name, G_VALUE_TYPE_NAME (param_values + i)); SIGNAL_UNLOCK (); return; } if (node->return_type != G_TYPE_NONE) { if (!return_value) { g_critical ("%s: return value `%s' for signal \"%s\" is (NULL)", G_STRLOC, type_debug_name (node->return_type), node->name); SIGNAL_UNLOCK (); return; } else if (!node->accumulator && !G_TYPE_CHECK_VALUE_TYPE (return_value, node->return_type & ~G_SIGNAL_TYPE_STATIC_SCOPE)) { g_critical ("%s: return value `%s' for signal \"%s\" is of type `%s'", G_STRLOC, type_debug_name (node->return_type), node->name, G_VALUE_TYPE_NAME (return_value)); SIGNAL_UNLOCK (); return; } } else return_value = NULL; #endif /* G_ENABLE_DEBUG */ /* optimize NOP emissions */ if (signal_check_skip_emission (node, instance, detail)) { /* nothing to do to emit this signal */ SIGNAL_UNLOCK (); /* g_printerr ("omitting emission of \"%s\"\n", node->name); */ return; } SIGNAL_UNLOCK (); signal_emit_unlocked_R (node, detail, instance, return_value, instance_and_params); } /** * g_signal_emit_valist: * @instance: the instance the signal is being emitted on. * @signal_id: the signal id * @detail: the detail * @var_args: a list of parameters to be passed to the signal, followed by a * location for the return value. If the return type of the signal * is #G_TYPE_NONE, the return value location can be omitted. * * Emits a signal. * * Note that g_signal_emit_valist() resets the return value to the default * if no handlers are connected, in contrast to g_signal_emitv(). */ void g_signal_emit_valist (gpointer instance, guint signal_id, GQuark detail, va_list var_args) { GValue *instance_and_params; GType signal_return_type; GValue *param_values; SignalNode *node; guint i, n_params; g_return_if_fail (G_TYPE_CHECK_INSTANCE (instance)); g_return_if_fail (signal_id > 0); SIGNAL_LOCK (); node = LOOKUP_SIGNAL_NODE (signal_id); if (!node || !g_type_is_a (G_TYPE_FROM_INSTANCE (instance), node->itype)) { g_warning ("%s: signal id `%u' is invalid for instance `%p'", G_STRLOC, signal_id, instance); SIGNAL_UNLOCK (); return; } #ifndef G_DISABLE_CHECKS if (detail && !(node->flags & G_SIGNAL_DETAILED)) { g_warning ("%s: signal id `%u' does not support detail (%u)", G_STRLOC, signal_id, detail); SIGNAL_UNLOCK (); return; } #endif /* !G_DISABLE_CHECKS */ /* optimize NOP emissions */ if (signal_check_skip_emission (node, instance, detail)) { /* nothing to do to emit this signal */ SIGNAL_UNLOCK (); /* g_printerr ("omitting emission of \"%s\"\n", node->name); */ return; } n_params = node->n_params; signal_return_type = node->return_type; instance_and_params = g_slice_alloc0 (sizeof (GValue) * (n_params + 1)); param_values = instance_and_params + 1; for (i = 0; i < node->n_params; i++) { gchar *error; GType ptype = node->param_types[i] & ~G_SIGNAL_TYPE_STATIC_SCOPE; gboolean static_scope = node->param_types[i] & G_SIGNAL_TYPE_STATIC_SCOPE; SIGNAL_UNLOCK (); G_VALUE_COLLECT_INIT (param_values + i, ptype, var_args, static_scope ? G_VALUE_NOCOPY_CONTENTS : 0, &error); if (error) { g_warning ("%s: %s", G_STRLOC, error); g_free (error); /* we purposely leak the value here, it might not be * in a sane state if an error condition occoured */ while (i--) g_value_unset (param_values + i); g_slice_free1 (sizeof (GValue) * (n_params + 1), instance_and_params); return; } SIGNAL_LOCK (); } SIGNAL_UNLOCK (); instance_and_params->g_type = 0; g_value_init (instance_and_params, G_TYPE_FROM_INSTANCE (instance)); g_value_set_instance (instance_and_params, instance); if (signal_return_type == G_TYPE_NONE) signal_emit_unlocked_R (node, detail, instance, NULL, instance_and_params); else { GValue return_value = G_VALUE_INIT; gchar *error = NULL; GType rtype = signal_return_type & ~G_SIGNAL_TYPE_STATIC_SCOPE; gboolean static_scope = signal_return_type & G_SIGNAL_TYPE_STATIC_SCOPE; g_value_init (&return_value, rtype); signal_emit_unlocked_R (node, detail, instance, &return_value, instance_and_params); G_VALUE_LCOPY (&return_value, var_args, static_scope ? G_VALUE_NOCOPY_CONTENTS : 0, &error); if (!error) g_value_unset (&return_value); else { g_warning ("%s: %s", G_STRLOC, error); g_free (error); /* we purposely leak the value here, it might not be * in a sane state if an error condition occurred */ } } for (i = 0; i < n_params; i++) g_value_unset (param_values + i); g_value_unset (instance_and_params); g_slice_free1 (sizeof (GValue) * (n_params + 1), instance_and_params); } /** * g_signal_emit: * @instance: the instance the signal is being emitted on. * @signal_id: the signal id * @detail: the detail * @...: parameters to be passed to the signal, followed by a * location for the return value. If the return type of the signal * is #G_TYPE_NONE, the return value location can be omitted. * * Emits a signal. * * Note that g_signal_emit() resets the return value to the default * if no handlers are connected, in contrast to g_signal_emitv(). */ void g_signal_emit (gpointer instance, guint signal_id, GQuark detail, ...) { va_list var_args; va_start (var_args, detail); g_signal_emit_valist (instance, signal_id, detail, var_args); va_end (var_args); } /** * g_signal_emit_by_name: * @instance: the instance the signal is being emitted on. * @detailed_signal: a string of the form "signal-name::detail". * @...: parameters to be passed to the signal, followed by a * location for the return value. If the return type of the signal * is #G_TYPE_NONE, the return value location can be omitted. * * Emits a signal. * * Note that g_signal_emit_by_name() resets the return value to the default * if no handlers are connected, in contrast to g_signal_emitv(). */ void g_signal_emit_by_name (gpointer instance, const gchar *detailed_signal, ...) { GQuark detail = 0; guint signal_id; g_return_if_fail (G_TYPE_CHECK_INSTANCE (instance)); g_return_if_fail (detailed_signal != NULL); SIGNAL_LOCK (); signal_id = signal_parse_name (detailed_signal, G_TYPE_FROM_INSTANCE (instance), &detail, TRUE); SIGNAL_UNLOCK (); if (signal_id) { va_list var_args; va_start (var_args, detailed_signal); g_signal_emit_valist (instance, signal_id, detail, var_args); va_end (var_args); } else g_warning ("%s: signal name `%s' is invalid for instance `%p'", G_STRLOC, detailed_signal, instance); } static inline gboolean accumulate (GSignalInvocationHint *ihint, GValue *return_accu, GValue *handler_return, SignalAccumulator *accumulator) { gboolean continue_emission; if (!accumulator) return TRUE; continue_emission = accumulator->func (ihint, return_accu, handler_return, accumulator->data); g_value_reset (handler_return); return continue_emission; } static gboolean signal_emit_unlocked_R (SignalNode *node, GQuark detail, gpointer instance, GValue *emission_return, const GValue *instance_and_params) { SignalAccumulator *accumulator; Emission emission; GClosure *class_closure; HandlerList *hlist; Handler *handler_list = NULL; GValue *return_accu, accu = G_VALUE_INIT; guint signal_id; gulong max_sequential_handler_number; gboolean return_value_altered = FALSE; #ifdef G_ENABLE_DEBUG IF_DEBUG (SIGNALS, g_trace_instance_signals == instance || g_trap_instance_signals == instance) { g_message ("%s::%s(%u) emitted (instance=%p, signal-node=%p)", g_type_name (G_TYPE_FROM_INSTANCE (instance)), node->name, detail, instance, node); if (g_trap_instance_signals == instance) G_BREAKPOINT (); } #endif /* G_ENABLE_DEBUG */ TRACE(GOBJECT_SIGNAL_EMIT(node->signal_id, detail, instance, G_TYPE_FROM_INSTANCE (instance))); SIGNAL_LOCK (); signal_id = node->signal_id; if (node->flags & G_SIGNAL_NO_RECURSE) { Emission *node = emission_find (g_restart_emissions, signal_id, detail, instance); if (node) { node->state = EMISSION_RESTART; SIGNAL_UNLOCK (); return return_value_altered; } } accumulator = node->accumulator; if (accumulator) { SIGNAL_UNLOCK (); g_value_init (&accu, node->return_type & ~G_SIGNAL_TYPE_STATIC_SCOPE); return_accu = &accu; SIGNAL_LOCK (); } else return_accu = emission_return; emission.instance = instance; emission.ihint.signal_id = node->signal_id; emission.ihint.detail = detail; emission.ihint.run_type = 0; emission.state = 0; emission.chain_type = G_TYPE_NONE; emission_push ((node->flags & G_SIGNAL_NO_RECURSE) ? &g_restart_emissions : &g_recursive_emissions, &emission); class_closure = signal_lookup_closure (node, instance); EMIT_RESTART: if (handler_list) handler_unref_R (signal_id, instance, handler_list); max_sequential_handler_number = g_handler_sequential_number; hlist = handler_list_lookup (signal_id, instance); handler_list = hlist ? hlist->handlers : NULL; if (handler_list) handler_ref (handler_list); emission.ihint.run_type = G_SIGNAL_RUN_FIRST; if ((node->flags & G_SIGNAL_RUN_FIRST) && class_closure) { emission.state = EMISSION_RUN; emission.chain_type = G_TYPE_FROM_INSTANCE (instance); SIGNAL_UNLOCK (); g_closure_invoke (class_closure, return_accu, node->n_params + 1, instance_and_params, &emission.ihint); if (!accumulate (&emission.ihint, emission_return, &accu, accumulator) && emission.state == EMISSION_RUN) emission.state = EMISSION_STOP; SIGNAL_LOCK (); emission.chain_type = G_TYPE_NONE; return_value_altered = TRUE; if (emission.state == EMISSION_STOP) goto EMIT_CLEANUP; else if (emission.state == EMISSION_RESTART) goto EMIT_RESTART; } if (node->emission_hooks) { gboolean need_destroy, was_in_call, may_recurse = TRUE; GHook *hook; emission.state = EMISSION_HOOK; hook = g_hook_first_valid (node->emission_hooks, may_recurse); while (hook) { SignalHook *signal_hook = SIGNAL_HOOK (hook); if (!signal_hook->detail || signal_hook->detail == detail) { GSignalEmissionHook hook_func = (GSignalEmissionHook) hook->func; was_in_call = G_HOOK_IN_CALL (hook); hook->flags |= G_HOOK_FLAG_IN_CALL; SIGNAL_UNLOCK (); need_destroy = !hook_func (&emission.ihint, node->n_params + 1, instance_and_params, hook->data); SIGNAL_LOCK (); if (!was_in_call) hook->flags &= ~G_HOOK_FLAG_IN_CALL; if (need_destroy) g_hook_destroy_link (node->emission_hooks, hook); } hook = g_hook_next_valid (node->emission_hooks, hook, may_recurse); } if (emission.state == EMISSION_RESTART) goto EMIT_RESTART; } if (handler_list) { Handler *handler = handler_list; emission.state = EMISSION_RUN; handler_ref (handler); do { Handler *tmp; if (handler->after) { handler_unref_R (signal_id, instance, handler_list); handler_list = handler; break; } else if (!handler->block_count && (!handler->detail || handler->detail == detail) && handler->sequential_number < max_sequential_handler_number) { SIGNAL_UNLOCK (); g_closure_invoke (handler->closure, return_accu, node->n_params + 1, instance_and_params, &emission.ihint); if (!accumulate (&emission.ihint, emission_return, &accu, accumulator) && emission.state == EMISSION_RUN) emission.state = EMISSION_STOP; SIGNAL_LOCK (); return_value_altered = TRUE; tmp = emission.state == EMISSION_RUN ? handler->next : NULL; } else tmp = handler->next; if (tmp) handler_ref (tmp); handler_unref_R (signal_id, instance, handler_list); handler_list = handler; handler = tmp; } while (handler); if (emission.state == EMISSION_STOP) goto EMIT_CLEANUP; else if (emission.state == EMISSION_RESTART) goto EMIT_RESTART; } emission.ihint.run_type = G_SIGNAL_RUN_LAST; if ((node->flags & G_SIGNAL_RUN_LAST) && class_closure) { emission.state = EMISSION_RUN; emission.chain_type = G_TYPE_FROM_INSTANCE (instance); SIGNAL_UNLOCK (); g_closure_invoke (class_closure, return_accu, node->n_params + 1, instance_and_params, &emission.ihint); if (!accumulate (&emission.ihint, emission_return, &accu, accumulator) && emission.state == EMISSION_RUN) emission.state = EMISSION_STOP; SIGNAL_LOCK (); emission.chain_type = G_TYPE_NONE; return_value_altered = TRUE; if (emission.state == EMISSION_STOP) goto EMIT_CLEANUP; else if (emission.state == EMISSION_RESTART) goto EMIT_RESTART; } if (handler_list) { Handler *handler = handler_list; emission.state = EMISSION_RUN; handler_ref (handler); do { Handler *tmp; if (handler->after && !handler->block_count && (!handler->detail || handler->detail == detail) && handler->sequential_number < max_sequential_handler_number) { SIGNAL_UNLOCK (); g_closure_invoke (handler->closure, return_accu, node->n_params + 1, instance_and_params, &emission.ihint); if (!accumulate (&emission.ihint, emission_return, &accu, accumulator) && emission.state == EMISSION_RUN) emission.state = EMISSION_STOP; SIGNAL_LOCK (); return_value_altered = TRUE; tmp = emission.state == EMISSION_RUN ? handler->next : NULL; } else tmp = handler->next; if (tmp) handler_ref (tmp); handler_unref_R (signal_id, instance, handler); handler = tmp; } while (handler); if (emission.state == EMISSION_STOP) goto EMIT_CLEANUP; else if (emission.state == EMISSION_RESTART) goto EMIT_RESTART; } EMIT_CLEANUP: emission.ihint.run_type = G_SIGNAL_RUN_CLEANUP; if ((node->flags & G_SIGNAL_RUN_CLEANUP) && class_closure) { gboolean need_unset = FALSE; emission.state = EMISSION_STOP; emission.chain_type = G_TYPE_FROM_INSTANCE (instance); SIGNAL_UNLOCK (); if (node->return_type != G_TYPE_NONE && !accumulator) { g_value_init (&accu, node->return_type & ~G_SIGNAL_TYPE_STATIC_SCOPE); need_unset = TRUE; } g_closure_invoke (class_closure, node->return_type != G_TYPE_NONE ? &accu : NULL, node->n_params + 1, instance_and_params, &emission.ihint); if (need_unset) g_value_unset (&accu); SIGNAL_LOCK (); emission.chain_type = G_TYPE_NONE; if (emission.state == EMISSION_RESTART) goto EMIT_RESTART; } if (handler_list) handler_unref_R (signal_id, instance, handler_list); emission_pop ((node->flags & G_SIGNAL_NO_RECURSE) ? &g_restart_emissions : &g_recursive_emissions, &emission); SIGNAL_UNLOCK (); if (accumulator) g_value_unset (&accu); TRACE(GOBJECT_SIGNAL_EMIT_END(node->signal_id, detail, instance, G_TYPE_FROM_INSTANCE (instance))); return return_value_altered; } static const gchar* type_debug_name (GType type) { if (type) { const char *name = g_type_name (type & ~G_SIGNAL_TYPE_STATIC_SCOPE); return name ? name : ""; } else return ""; } /** * g_signal_accumulator_true_handled: * @ihint: standard #GSignalAccumulator parameter * @return_accu: standard #GSignalAccumulator parameter * @handler_return: standard #GSignalAccumulator parameter * @dummy: standard #GSignalAccumulator parameter * * A predefined #GSignalAccumulator for signals that return a * boolean values. The behavior that this accumulator gives is * that a return of %TRUE stops the signal emission: no further * callbacks will be invoked, while a return of %FALSE allows * the emission to continue. The idea here is that a %TRUE return * indicates that the callback handled the signal, * and no further handling is needed. * * Since: 2.4 * * Returns: standard #GSignalAccumulator result */ gboolean g_signal_accumulator_true_handled (GSignalInvocationHint *ihint, GValue *return_accu, const GValue *handler_return, gpointer dummy) { gboolean continue_emission; gboolean signal_handled; signal_handled = g_value_get_boolean (handler_return); g_value_set_boolean (return_accu, signal_handled); continue_emission = !signal_handled; return continue_emission; } /** * g_signal_accumulator_first_wins: * @ihint: standard #GSignalAccumulator parameter * @return_accu: standard #GSignalAccumulator parameter * @handler_return: standard #GSignalAccumulator parameter * @dummy: standard #GSignalAccumulator parameter * * A predefined #GSignalAccumulator for signals intended to be used as a * hook for application code to provide a particular value. Usually * only one such value is desired and multiple handlers for the same * signal don't make much sense (except for the case of the default * handler defined in the class structure, in which case you will * usually want the signal connection to override the class handler). * * This accumulator will use the return value from the first signal * handler that is run as the return value for the signal and not run * any further handlers (ie: the first handler "wins"). * * Returns: standard #GSignalAccumulator result * * Since: 2.28 **/ gboolean g_signal_accumulator_first_wins (GSignalInvocationHint *ihint, GValue *return_accu, const GValue *handler_return, gpointer dummy) { g_value_copy (handler_return, return_accu); return FALSE; }