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Migrating docs.

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* docs/reference/gobject/tmpl/signals.sgml:
	* gobject/gclosure.c:
	* gobject/gobject.c:
	* gobject/gsignal.c:
	* gobject/gsignal.h:
	  Migrating docs.


svn path=/trunk/; revision=7083
This commit is contained in:
Stefan Kost
2008-06-22 09:29:52 +00:00
parent 0f62f41d2c
commit 356fe46531
6 changed files with 827 additions and 927 deletions
Download Patch File Download Diff File Expand all files Collapse all files

12
gobject/gclosure.c
View File

@@ -893,6 +893,18 @@ g_type_iface_meta_marshal (GClosure *closure,
callback);
}
/**
* g_signal_type_cclosure_new:
* @itype: the #GType identifier of an interface or classed type
* @struct_offset: the offset of the member function of @itype's class
* structure which is to be invoked by the new closure
*
* Creates a new closure which invokes the function found at the offset
* @struct_offset in the class structure of the interface or classed type
* identified by @itype.
*
* Returns: a new #GCClosure
*/
GClosure*
g_signal_type_cclosure_new (GType itype,
guint struct_offset)

33
gobject/gobject.c
View File

@@ -2845,6 +2845,39 @@ g_value_dup_object (const GValue *value)
return value->data[0].v_pointer ? g_object_ref (value->data[0].v_pointer) : NULL;
}
/**
* g_signal_connect_object:
* @instance: the instance to connect to.
* @detailed_signal: a string of the form "signal-name::detail".
* @c_handler: the #GCallback to connect.
* @gobject: the object to pass as data to @c_handler.
* @connect_flags: a combination of #GConnnectFlags.
*
* This is similar to g_signal_connect_data(), but uses a closure which
* ensures that the @gobject stays alive during the call to @c_handler
* by temporarily adding a reference count to @gobject.
*
* Note that there is a bug in GObject that makes this function
* much less useful than it might seem otherwise. Once @gobject is
* disposed, the callback will no longer be called, but, the signal
* handler is <emphasis>not</emphasis> currently disconnected. If the
* @instance is itself being freed at the same time than this doesn't
* matter, since the signal will automatically be removed, but
* if @instance persists, then the signal handler will leak. You
* should not remove the signal yourself because in a future versions of
* GObject, the handler <emphasis>will</emphasis> automatically
* be disconnected.
*
* It's possible to work around this problem in a way that will
* continue to work with future versions of GObject by checking
* that the signal handler is still connected before disconnected it:
* <informalexample><programlisting>
* if (g_signal_handler_is_connected (instance, id))
* g_signal_handler_disconnect (instance, id);
* </programlisting></informalexample>
*
* Returns: the handler id.
*/
gulong
g_signal_connect_object (gpointer instance,
const gchar *detailed_signal,

551
gobject/gsignal.c
View File

@@ -19,7 +19,67 @@
* this code is based on the original GtkSignal implementation
* for the Gtk+ library by Peter Mattis <petm@xcf.berkeley.edu>
*/
/**
* 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 <emphasis>emission</emphasis>
* 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
* 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:
* <variablelist>
* <varlistentry><term></term><listitem><para>
* 1 - Invocation of the object method handler for %G_SIGNAL_RUN_FIRST signals
* </para></listitem></varlistentry>
* <varlistentry><term></term><listitem><para>
* 2 - Invocation of normal user-provided signal handlers (<emphasis>after</emphasis> flag %FALSE)
* </para></listitem></varlistentry>
* <varlistentry><term></term><listitem><para>
* 3 - Invocation of the object method handler for %G_SIGNAL_RUN_LAST signals
* </para></listitem></varlistentry>
* <varlistentry><term></term><listitem><para>
* 4 - Invocation of user provided signal handlers, connected with an <emphasis>after</emphasis> flag of %TRUE
* </para></listitem></varlistentry>
* <varlistentry><term></term><listitem><para>
* 5 - Invocation of the object method handler for %G_SIGNAL_RUN_CLEANUP signals
* </para></listitem></varlistentry>
* </variablelist>
* 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 <emphasis>blocked</emphasis>, 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.
*/
/*
* MT safe
*/
@@ -746,6 +806,20 @@ _g_signals_destroy (GType itype)
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,
@@ -801,6 +875,20 @@ signal_finalize_hook (GHookList *hook_list,
}
}
/**
* 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,
@@ -856,6 +944,14 @@ g_signal_add_emission_hook (guint signal_id,
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)
@@ -918,6 +1014,19 @@ signal_parse_name (const gchar *name,
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: Location to store the signal id.
* @detail_p: 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,
@@ -949,6 +1058,16 @@ g_signal_parse_name (const gchar *detailed_signal,
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)
@@ -994,6 +1113,21 @@ g_signal_stop_emission_by_name (gpointer 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)
@@ -1022,6 +1156,17 @@ g_signal_lookup (const gchar *name,
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: Newly allocated array of signal IDs.
*/
guint*
g_signal_list_ids (GType itype,
guint *n_ids)
@@ -1069,6 +1214,16 @@ g_signal_list_ids (GType 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.
*/
G_CONST_RETURN gchar*
g_signal_name (guint signal_id)
{
@@ -1083,6 +1238,19 @@ g_signal_name (guint signal_id)
return (char*) name;
}
/**
* g_signal_query:
* @signal_id: The signal id of the signal to query information for.
* @query: 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)
@@ -1108,6 +1276,38 @@ g_signal_query (guint signal_id,
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 with this signal.
* @accumulator: the accumulator for this signal; may be %NULL.
* @accu_data: user data for the @accumulator.
* @c_marshaller: the function to translate arrays of parameter values to
* signal emissions into C language callback invocations.
* @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.
*
* Returns: the signal id
*/
guint
g_signal_new (const gchar *signal_name,
GType itype,
@@ -1210,6 +1410,30 @@ signal_add_class_closure (SignalNode *node,
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: 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: the function to translate arrays of parameter values to
* signal emissions into C language callback invocations.
* @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: an array 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.
*
* Returns: the signal id
*/
guint
g_signal_newv (const gchar *signal_name,
GType itype,
@@ -1344,6 +1568,30 @@ g_signal_newv (const gchar *signal_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: the function to translate arrays of parameter values to
* signal emissions into C language callback invocations.
* @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.
*
* Returns: the signal id
*/
guint
g_signal_new_valist (const gchar *signal_name,
GType itype,
@@ -1433,6 +1681,17 @@ signal_destroy_R (SignalNode *signal_node)
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.
*/
void
g_signal_override_class_closure (guint signal_id,
GType instance_type,
@@ -1459,6 +1718,17 @@ g_signal_override_class_closure (guint signal_id,
SIGNAL_UNLOCK ();
}
/**
* g_signal_chain_from_overridden:
* @instance_and_params: 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().
*/
void
g_signal_chain_from_overridden (const GValue *instance_and_params,
GValue *return_value)
@@ -1518,6 +1788,14 @@ g_signal_chain_from_overridden (const GValue *instance_and_params,
SIGNAL_UNLOCK ();
}
/**
* g_signal_get_invocation_hint:
* @instance: the instance to query
*
* Returns the invocation hint of the innermost signal emission of instance.
*
* Returns: the invocation hint of the innermost signal emission.
*/
GSignalInvocationHint*
g_signal_get_invocation_hint (gpointer instance)
{
@@ -1532,6 +1810,19 @@ g_signal_get_invocation_hint (gpointer instance)
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,
@@ -1574,6 +1865,18 @@ g_signal_connect_closure_by_id (gpointer instance,
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,
@@ -1620,6 +1923,23 @@ g_signal_connect_closure (gpointer instance,
return handler_seq_no;
}
/**
* 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 <literal>..._after()</literal> or
* <literal>..._swapped()</literal> variants of this function.
*
* Returns: the handler id
*/
gulong
g_signal_connect_data (gpointer instance,
const gchar *detailed_signal,
@@ -1672,6 +1992,20 @@ g_signal_connect_data (gpointer instance,
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)
@@ -1696,6 +2030,25 @@ g_signal_handler_block (gpointer instance,
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)
@@ -1719,6 +2072,18 @@ g_signal_handler_unblock (gpointer instance,
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)
@@ -1742,6 +2107,15 @@ g_signal_handler_disconnect (gpointer instance,
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)
@@ -1801,6 +2175,25 @@ g_signal_handlers_destroy (gpointer instance)
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: 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,
@@ -1862,6 +2255,27 @@ signal_handlers_foreach_matched_R (gpointer 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: 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,
@@ -1888,6 +2302,28 @@ g_signal_handlers_block_matched (gpointer instance,
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: 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,
@@ -1914,6 +2350,27 @@ g_signal_handlers_unblock_matched (gpointer instance,
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: 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,
@@ -1940,6 +2397,24 @@ g_signal_handlers_disconnect_matched (gpointer instance,
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,
@@ -2023,6 +2498,21 @@ signal_check_skip_emission (SignalNode *node,
return TRUE;
}
/**
* g_signal_emitv:
* @instance_and_params: 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,
@@ -2111,6 +2601,20 @@ g_signal_emitv (const GValue *instance_and_params,
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,
@@ -2231,6 +2735,20 @@ g_signal_emit_valist (gpointer instance,
g_free (free_me);
}
/**
* 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,
@@ -2244,6 +2762,19 @@ g_signal_emit (gpointer instance,
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,
@@ -2590,6 +3121,24 @@ type_debug_name (GType type)
return "<invalid>";
}
/**
* 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 coninue. The idea here is that a %TRUE return
* indicates that the callback <emphasis>handled</emphasis> 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,

223
gobject/gsignal.h
View File

@@ -33,11 +33,57 @@ G_BEGIN_DECLS
/* --- typedefs --- */
typedef struct _GSignalQuery GSignalQuery;
typedef struct _GSignalInvocationHint GSignalInvocationHint;
/**
* GSignalCMarshaller:
*
* This is the signature of marshaller functions, required to marshall
* arrays of parameter values to signal emissions into C language callback
* invocations. It is merely an alias to #GClosureMarshal since the #GClosure
* mechanism takes over responsibility of actual function invocation for the
* signal system.
*/
typedef GClosureMarshal GSignalCMarshaller;
/**
* GSignalEmissionHook:
* @ihint: Signal invocation hint, see #GSignalInvocationHint.
* @n_param_values: the number of parameters to the function, including
* the instance on which the signal was emitted.
* @param_values: the instance on which the signal was emitted, followed by the
* parameters of the emission.
* @data: user data associated with the hook.
*
* A simple function pointer to get invoked when the signal is emitted. This
* allows you to tie a hook to the signal type, so that it will trap all
* emissions of that signal, from any object.
*
* You may not attach these to signals created with the #G_SIGNAL_NO_HOOKS flag.
*
* Returns: whether it wants to stay connected. If it returns %FALSE, the signal
* hook is disconnected (and destroyed).
*/
typedef gboolean (*GSignalEmissionHook) (GSignalInvocationHint *ihint,
guint n_param_values,
const GValue *param_values,
gpointer data);
/**
* GSignalAccumulator:
* @ihint: Signal invocation hint, see #GSignalInvocationHint.
* @return_accu: Accumulator to collect callback return values in, this
* is the return value of the current signal emission.
* @handler_return: A #GValue holding the return value of the signal handler.
* @data: Callback data that was specified when creating the signal.
*
* The signal accumulator is a special callback function that can be used
* to collect return values of the various callbacks that are called
* during a signal emission. The signal accumulator is specified at signal
* creation time, if it is left %NULL, no accumulation of callback return
* values is performed. The return value of signal emissions is then the
* value returned by the last callback.
*
* Returns: The accumulator function returns whether the signal emission
* should be aborted. Returning %FALSE means to abort the
* current emission and %TRUE is returned for continuation.
*/
typedef gboolean (*GSignalAccumulator) (GSignalInvocationHint *ihint,
GValue *return_accu,
const GValue *handler_return,
@@ -45,6 +91,28 @@ typedef gboolean (*GSignalAccumulator) (GSignalInvocationHint *ihint,
/* --- run, match and connect types --- */
/**
* GSignalFlags:
* @G_SIGNAL_RUN_FIRST: Invoke the object method handler in the first emission stage.
* @G_SIGNAL_RUN_LAST: Invoke the object method handler in the third emission stage.
* @G_SIGNAL_RUN_CLEANUP: Invoke the object method handler in the last emission stage.
* @G_SIGNAL_NO_RECURSE: Signals being emitted for an object while currently being in
* emission for this very object will not be emitted recursively,
* but instead cause the first emission to be restarted.
* @G_SIGNAL_DETAILED: This signal supports "::detail" appendices to the signal name
* upon handler connections and emissions.
* @G_SIGNAL_ACTION: Action signals are signals that may freely be emitted on alive
* objects from user code via g_signal_emit() and friends, without
* the need of being embedded into extra code that performs pre or
* post emission adjustments on the object. They can also be thought
* of as object methods which can be called generically by
* third-party code.
* @G_SIGNAL_NO_HOOKS: No emissions hooks are supported for this signal.
*
* The signal flags are used to specify a signal's behaviour, the overall
* signal description outlines how especially the RUN flags control the
* stages of a signal emission.
*/
typedef enum
{
G_SIGNAL_RUN_FIRST = 1 << 0,
@@ -55,12 +123,40 @@ typedef enum
G_SIGNAL_ACTION = 1 << 5,
G_SIGNAL_NO_HOOKS = 1 << 6
} GSignalFlags;
/**
* G_SIGNAL_FLAGS_MASK:
*
* A mask for all #GSignalFlags bits.
*/
#define G_SIGNAL_FLAGS_MASK 0x7f
/**
* GConnectFlags:
* @G_CONNECT_AFTER: whether the handler should be called before or after the
* default handler of the signal.
* @G_CONNECT_SWAPPED: whether the instance and data should be swapped when
* calling the handler.
*
* The connection flags are used to specify the behaviour of a signal's
* connection.
*/
typedef enum
{
G_CONNECT_AFTER = 1 << 0,
G_CONNECT_SWAPPED = 1 << 1
} GConnectFlags;
/**
* GSignalMatchType:
* @G_SIGNAL_MATCH_ID: The signal id must be equal.
* @G_SIGNAL_MATCH_DETAIL: The signal detail be equal.
* @G_SIGNAL_MATCH_CLOSURE: The closure must be the same.
* @G_SIGNAL_MATCH_FUNC: The C closure callback must be the same.
* @G_SIGNAL_MATCH_DATA: The closure data must be the same.
* @G_SIGNAL_MATCH_UNBLOCKED: Only unblocked signals may matched.
*
* The match types specify what g_signal_handlers_block_matched(),
* g_signal_handlers_unblock_matched() and g_signal_handlers_disconnect_matched()
* match signals by.
*/
typedef enum
{
G_SIGNAL_MATCH_ID = 1 << 0,
@@ -70,17 +166,74 @@ typedef enum
G_SIGNAL_MATCH_DATA = 1 << 4,
G_SIGNAL_MATCH_UNBLOCKED = 1 << 5
} GSignalMatchType;
/**
* G_SIGNAL_MATCH_MASK:
*
* A mask for all #GSignalMatchType bits.
*/
#define G_SIGNAL_MATCH_MASK 0x3f
/**
* G_SIGNAL_TYPE_STATIC_SCOPE:
*
* This macro flags signal argument types for which the signal system may
* assume that instances thereof remain persistent across all signal emissions
* they are used in. This is only useful for non ref-counted, value-copy types.
*
* To flag a signal argument in this way, add
* <literal>| G_SIGNAL_TYPE_STATIC_SCOPE</literal> to the corresponding argument
* of g_signal_new().
* |[
* g_signal_new ("size_request",
* G_TYPE_FROM_CLASS (gobject_class),
* G_SIGNAL_RUN_FIRST,
* G_STRUCT_OFFSET (GtkWidgetClass, size_request),
* NULL, NULL,
* _gtk_marshal_VOID__BOXED,
* G_TYPE_NONE, 1,
* GTK_TYPE_REQUISITION | G_SIGNAL_TYPE_STATIC_SCOPE);
* ]|
*/
#define G_SIGNAL_TYPE_STATIC_SCOPE (G_TYPE_FLAG_RESERVED_ID_BIT)
/* --- signal information --- */
/**
* GSignalInvocationHint:
* @signal_id: The signal id of the signal invoking the callback
* @detail: The detail passed on for this emission
* @run_type: The stage the signal emission is currently in, this
* field will contain one of %G_SIGNAL_RUN_FIRST,
* %G_SIGNAL_RUN_LAST or %G_SIGNAL_RUN_CLEANUP.
*
* The #GSignalInvocationHint structure is used to pass on additional information
* to callbacks during a signal emission.
*/
struct _GSignalInvocationHint
{
guint signal_id;
GQuark detail;
GSignalFlags run_type;
};
/**
* GSignalQuery:
* @signal_id: The signal id of the signal being queried, or 0 if the
* signal to be queried was unknown.
* @signal_name: The signal name.
* @itype: The interface/instance type that this signal can be emitted for.
* @signal_flags: The signal flags as passed in to g_signal_new().
* @return_type: The return type for user callbacks.
* @n_params: The number of parameters that user callbacks take.
* @param_types: The individual parameter types for user callbacks, note that the
* effective callback signature is:
* <programlisting>
* @return_type callback (#gpointer data1,
* [#param_types param_names,]
* #gpointer data2);
* </programlisting>
*
* A structure holding in-depth information for a specific signal. It is
* filled in by the g_signal_query() function.
*/
struct _GSignalQuery
{
guint signal_id;
@@ -236,20 +389,90 @@ void g_signal_chain_from_overridden (const GValue *instance_and_param
/* --- convenience --- */
/**
* g_signal_connect:
* @instance: the instance to connect to.
* @detailed_signal: a string of the form "signal-name::detail".
* @c_handler: the #GCallback to connect.
* @data: data to pass to @c_handler calls.
*
* Connects a #GCallback function to a signal for a particular object.
*
* The handler will be called before the default handler of the signal.
*
* Returns: the handler id
*/
#define g_signal_connect(instance, detailed_signal, c_handler, data) \
g_signal_connect_data ((instance), (detailed_signal), (c_handler), (data), NULL, (GConnectFlags) 0)
/**
* g_signal_connect_after:
* @instance: the instance to connect to.
* @detailed_signal: a string of the form "signal-name::detail".
* @c_handler: the #GCallback to connect.
* @data: data to pass to @c_handler calls.
*
* Connects a #GCallback function to a signal for a particular object.
*
* The handler will be called after the default handler of the signal.
*
* Returns: the handler id
*/
#define g_signal_connect_after(instance, detailed_signal, c_handler, data) \
g_signal_connect_data ((instance), (detailed_signal), (c_handler), (data), NULL, G_CONNECT_AFTER)
/**
* g_signal_connect_swapped:
* @instance: the instance to connect to.
* @detailed_signal: a string of the form "signal-name::detail".
* @c_handler: the #GCallback to connect.
* @data: data to pass to @c_handler calls.
*
* Connects a #GCallback function to a signal for a particular object.
*
* The instance on which the signal is emitted and @data will be swapped when
* calling the handler.
*
* Returns: the handler id
*/
#define g_signal_connect_swapped(instance, detailed_signal, c_handler, data) \
g_signal_connect_data ((instance), (detailed_signal), (c_handler), (data), NULL, G_CONNECT_SWAPPED)
/**
* g_signal_handlers_disconnect_by_func:
* @instance: The instance to remove handlers from.
* @func: The C closure callback of the handlers (useless for non-C closures).
* @data: The closure data of the handlers' closures.
*
* Disconnects all handlers on an instance that match @func and @data.
*
* Returns: The number of handlers that matched.
*/
#define g_signal_handlers_disconnect_by_func(instance, func, data) \
g_signal_handlers_disconnect_matched ((instance), \
(GSignalMatchType) (G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA), \
0, 0, NULL, (func), (data))
/**
* g_signal_handlers_block_by_func:
* @instance: The instance to block handlers from.
* @func: The C closure callback of the handlers (useless for non-C closures).
* @data: The closure data of the handlers' closures.
*
* Blocks all handlers on an instance that match @func and @data.
*
* Returns: The number of handlers that matched.
*/
#define g_signal_handlers_block_by_func(instance, func, data) \
g_signal_handlers_block_matched ((instance), \
(GSignalMatchType) (G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA), \
0, 0, NULL, (func), (data))
/**
* g_signal_handlers_unblock_by_func:
* @instance: The instance to unblock handlers from.
* @func: The C closure callback of the handlers (useless for non-C closures).
* @data: The closure data of the handlers' closures.
*
* Unblocks all handlers on an instance that match @func and @data.
*
* Returns: The number of handlers that matched.
*/
#define g_signal_handlers_unblock_by_func(instance, func, data) \
g_signal_handlers_unblock_matched ((instance), \
(GSignalMatchType) (G_SIGNAL_MATCH_FUNC | G_SIGNAL_MATCH_DATA), \