Signals

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struct GSignalInvocationHint

struct GSignalInvocationHint
{
  guint		signal_id;
  GQuark	detail;
  GSignalFlags	run_type;
};

The GSignalInvocationHint structure is used to pass on additional information to callbacks during a signal emission.

guint `signal_id`	The signal id of the signal invoking the callback
GQuark `detail`	The detail passed on for this emission
GSignalFlags `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`.

GSignalAccumulator ()

gboolean    (*GSignalAccumulator)           (GSignalInvocationHint *ihint,
                                             GValue *return_accu,
                                             const GValue *handler_return,
                                             gpointer data);

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.

`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`�:
`data`�:
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.

GSignalCMarshaller

typedef GClosureMarshal			 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.

GSignalEmissionHook ()

gboolean    (*GSignalEmissionHook)          (GSignalInvocationHint *ihint,
                                             guint n_param_values,
                                             const GValue *param_values,
                                             gpointer data);

`ihint`�:
`n_param_values`�:
`param_values`�:
`data`�:
Returns :

enum GSignalFlags

typedef enum
{
  G_SIGNAL_RUN_FIRST	= 1 << 0,
  G_SIGNAL_RUN_LAST	= 1 << 1,
  G_SIGNAL_RUN_CLEANUP	= 1 << 2,
  G_SIGNAL_NO_RECURSE	= 1 << 3,
  G_SIGNAL_DETAILED	= 1 << 4,
  G_SIGNAL_ACTION	= 1 << 5,
  G_SIGNAL_NO_HOOKS	= 1 << 6
} GSignalFlags;

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.

`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" appendixes 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 by third-party code generically callable object methods.
`G_SIGNAL_NO_HOOKS`	No emissions hooks are supported for this signal.

enum GSignalMatchType

typedef enum
{
  G_SIGNAL_MATCH_ID	   = 1 << 0,
  G_SIGNAL_MATCH_DETAIL	   = 1 << 1,
  G_SIGNAL_MATCH_CLOSURE   = 1 << 2,
  G_SIGNAL_MATCH_FUNC	   = 1 << 3,
  G_SIGNAL_MATCH_DATA	   = 1 << 4,
  G_SIGNAL_MATCH_UNBLOCKED = 1 << 5
} GSignalMatchType;

struct GSignalQuery

struct GSignalQuery
{
  guint		signal_id;
  const gchar  *signal_name;
  GType		itype;
  GSignalFlags	signal_flags;
  GType		return_type; /* mangled with G_SIGNAL_TYPE_STATIC_SCOPE flag */
  guint		n_params;
  const GType  *param_types; /* mangled with G_SIGNAL_TYPE_STATIC_SCOPE flag */
};

A structure holding in-depth information for a specific signal. It is filled in by the g_signal_query() function.

guint signal_id The signal id of the signal being queried, or 0 if the signal to be queried was unknown.

const gchar *signal_name The signal name.

GType itype The interface/instance type that this signal can be emitted for.

GSignalFlags signal_flags The signal flags as passed in to g_signal_new().

GType return_type The return type for user callbacks.

guint n_params The number of parameters that user callbacks take.

const GType *param_types

The individual parameter types for user callbacks, note that the effective callback signature is:

return_type callback (gpointer     data1,
                      [param_types param_names,]
                       gpointer     data2);

G_SIGNAL_TYPE_STATIC_SCOPE

#define	G_SIGNAL_TYPE_STATIC_SCOPE (G_TYPE_FLAG_RESERVED_ID_BIT)

G_SIGNAL_MATCH_MASK

#define G_SIGNAL_MATCH_MASK  0x3f

G_SIGNAL_FLAGS_MASK

#define G_SIGNAL_FLAGS_MASK  0x7f

g_signal_new ()

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,
                                             ...);

`signal_name`�:
`itype`�:
`signal_flags`�:
`class_offset`�:
`accumulator`�:
`accu_data`�:
`c_marshaller`�:
`return_type`�:
`n_params`�:
`...`�:
Returns :

g_signal_newv ()

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);

`signal_name`�:
`itype`�:
`signal_flags`�:
`class_closure`�:
`accumulator`�:
`accu_data`�:
`c_marshaller`�:
`return_type`�:
`n_params`�:
`param_types`�:
Returns :

g_signal_new_valist ()

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);

`signal_name`�:
`itype`�:
`signal_flags`�:
`class_closure`�:
`accumulator`�:
`accu_data`�:
`c_marshaller`�:
`return_type`�:
`n_params`�:
`args`�:
Returns :

g_signal_query ()

void        g_signal_query                  (guint signal_id,
                                             GSignalQuery *query);

Query 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.

`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.

g_signal_lookup ()

guint       g_signal_lookup                 (const gchar *name,
                                             GType itype);

`name`�:
`itype`�:
Returns :

g_signal_name ()

G_CONST_RETURN gchar* g_signal_name         (guint signal_id);

`signal_id`�:
Returns :

g_signal_list_ids ()

guint*      g_signal_list_ids               (GType itype,
                                             guint *n_ids);

List the signals by id, that a certain instance or interface type created. Further information about the signals can be acquired through g_signal_query().

`itype`�:	Instance or interface type.
`n_ids`�:	Location to store the number of signal ids for `itype`.
Returns :	Newly allocated array of signal IDs.

g_signal_emit ()

void        g_signal_emit                   (gpointer instance,
                                             guint signal_id,
                                             GQuark detail,
                                             ...);

`instance`�:
`signal_id`�:
`detail`�:
`...`�:

g_signal_emit_by_name ()

void        g_signal_emit_by_name           (gpointer instance,
                                             const gchar *detailed_signal,
                                             ...);

`instance`�:
`detailed_signal`�:
`...`�:

g_signal_emitv ()

void        g_signal_emitv                  (const GValue *instance_and_params,
                                             guint signal_id,
                                             GQuark detail,
                                             GValue *return_value);

`instance_and_params`�:
`signal_id`�:
`detail`�:
`return_value`�:

g_signal_emit_valist ()

void        g_signal_emit_valist            (gpointer instance,
                                             guint signal_id,
                                             GQuark detail,
                                             va_list var_args);

`instance`�:
`signal_id`�:
`detail`�:
`var_args`�:

g_signal_connect()

#define     g_signal_connect(instance, detailed_signal, c_handler, data)

`instance`�:
`detailed_signal`�:
`c_handler`�:
`data`�:

g_signal_connect_after()

#define     g_signal_connect_after(instance, detailed_signal, c_handler, data)

`instance`�:
`detailed_signal`�:
`c_handler`�:
`data`�:

g_signal_connect_swapped()

#define     g_signal_connect_swapped(instance, detailed_signal, c_handler, data)

`instance`�:
`detailed_signal`�:
`c_handler`�:
`data`�:

g_signal_connect_object ()

gulong      g_signal_connect_object         (gpointer instance,
                                             const gchar *detailed_signal,
                                             GCallback c_handler,
                                             gpointer gobject,
                                             GConnectFlags connect_flags);

`instance`�:
`detailed_signal`�:
`c_handler`�:
`gobject`�:
`connect_flags`�:
Returns :

enum GConnectFlags

typedef enum
{
  G_CONNECT_AFTER	= 1 << 0,
  G_CONNECT_SWAPPED	= 1 << 1
} GConnectFlags;

g_signal_connect_data ()

gulong      g_signal_connect_data           (gpointer instance,
                                             const gchar *detailed_signal,
                                             GCallback c_handler,
                                             gpointer data,
                                             GClosureNotify destroy_data,
                                             GConnectFlags connect_flags);

`instance`�:
`detailed_signal`�:
`c_handler`�:
`data`�:
`destroy_data`�:
`connect_flags`�:
Returns :

g_signal_connect_closure ()

gulong      g_signal_connect_closure        (gpointer instance,
                                             const gchar *detailed_signal,
                                             GClosure *closure,
                                             gboolean after);

`instance`�:
`detailed_signal`�:
`closure`�:
`after`�:
Returns :

g_signal_connect_closure_by_id ()

gulong      g_signal_connect_closure_by_id  (gpointer instance,
                                             guint signal_id,
                                             GQuark detail,
                                             GClosure *closure,
                                             gboolean after);

`instance`�:
`signal_id`�:
`detail`�:
`closure`�:
`after`�:
Returns :

g_signal_handler_block ()

void        g_signal_handler_block          (gpointer instance,
                                             gulong handler_id);

g_signal_handler_block() 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 passed into g_signal_handler_block() has to be a valid signal handler id, connected to a signal of instance.

`instance`�:	The instance to block the signal handler of.
`handler_id`�:	Handler id of the handler to be blocked.

g_signal_handler_unblock ()

void        g_signal_handler_unblock        (gpointer instance,
                                             gulong handler_id);

g_signal_handler_unblock() 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 passed into g_signal_handler_unblock() has to be a valid id of a signal handler that is connected to a signal of instance and is currently blocked.

`instance`�:	The instance to unblock the signal handler of.
`handler_id`�:	Handler id of the handler to be unblocked.

g_signal_handler_disconnect ()

void        g_signal_handler_disconnect     (gpointer instance,
                                             gulong handler_id);

g_signal_handler_disconnect() 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 passed into g_signal_handler_disconnect() has to be a valid signal handler id, connected to a signal of instance.

`instance`�:	The instance to remove the signal handler from.
`handler_id`�:	Handler id of the handler to be disconnected.

g_signal_handler_find ()

gulong      g_signal_handler_find           (gpointer instance,
                                             GSignalMatchType mask,
                                             guint signal_id,
                                             GQuark detail,
                                             GClosure *closure,
                                             gpointer func,
                                             gpointer data);

Find 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.

`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.
Returns :	A valid non-0 signal handler id for a successful match.

g_signal_handlers_block_matched ()

guint       g_signal_handlers_block_matched (gpointer instance,
                                             GSignalMatchType mask,
                                             guint signal_id,
                                             GQuark detail,
                                             GClosure *closure,
                                             gpointer func,
                                             gpointer data);

This function 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.

`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.
Returns :	The amount of handlers that got blocked.

g_signal_handlers_unblock_matched ()

guint       g_signal_handlers_unblock_matched
                                            (gpointer instance,
                                             GSignalMatchType mask,
                                             guint signal_id,
                                             GQuark detail,
                                             GClosure *closure,
                                             gpointer func,
                                             gpointer data);

This function 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.

`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.
Returns :	The amount of handlers that got unblocked.

g_signal_handlers_disconnect_matched ()

guint       g_signal_handlers_disconnect_matched
                                            (gpointer instance,
                                             GSignalMatchType mask,
                                             guint signal_id,
                                             GQuark detail,
                                             GClosure *closure,
                                             gpointer func,
                                             gpointer data);

This function 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.

`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.
Returns :	The amount of handlers that got disconnected.

g_signal_handler_is_connected ()

gboolean    g_signal_handler_is_connected   (gpointer instance,
                                             gulong handler_id);

`instance`�:
`handler_id`�:
Returns :

g_signal_handlers_block_by_func()

#define     g_signal_handlers_block_by_func(instance, func, data)

`instance`�:
`func`�:
`data`�:

g_signal_handlers_unblock_by_func()

#define     g_signal_handlers_unblock_by_func(instance, func, data)

`instance`�:
`func`�:
`data`�:

g_signal_handlers_disconnect_by_func()

#define     g_signal_handlers_disconnect_by_func(instance, func, data)

`instance`�:
`func`�:
`data`�:

g_signal_has_handler_pending ()

gboolean    g_signal_has_handler_pending    (gpointer instance,
                                             guint signal_id,
                                             GQuark detail,
                                             gboolean may_be_blocked);

`instance`�:
`signal_id`�:
`detail`�:
`may_be_blocked`�:
Returns :

g_signal_stop_emission ()

void        g_signal_stop_emission          (gpointer instance,
                                             guint signal_id,
                                             GQuark detail);

`instance`�:
`signal_id`�:
`detail`�:

g_signal_stop_emission_by_name ()

void        g_signal_stop_emission_by_name  (gpointer instance,
                                             const gchar *detailed_signal);

`instance`�:
`detailed_signal`�:

g_signal_override_class_closure ()

void        g_signal_override_class_closure (guint signal_id,
                                             GType instance_type,
                                             GClosure *class_closure);

`signal_id`�:
`instance_type`�:
`class_closure`�:

g_signal_chain_from_overridden ()

void        g_signal_chain_from_overridden  (const GValue *instance_and_params,
                                             GValue *return_value);

`instance_and_params`�:
`return_value`�:

g_signal_add_emission_hook ()

gulong      g_signal_add_emission_hook      (guint signal_id,
                                             GQuark quark,
                                             GSignalEmissionHook hook_func,
                                             gpointer hook_data,
                                             GDestroyNotify data_destroy);

`signal_id`�:
`quark`�:
`hook_func`�:
`hook_data`�:
`data_destroy`�:
Returns :

g_signal_remove_emission_hook ()

void        g_signal_remove_emission_hook   (guint signal_id,
                                             gulong hook_id);

`signal_id`�:
`hook_id`�:

g_signal_parse_name ()

gboolean    g_signal_parse_name             (const gchar *detailed_signal,
                                             GType itype,
                                             guint *signal_id_p,
                                             GQuark *detail_p,
                                             gboolean force_detail_quark);

Internal function to parse a signal names into its signal_id and detail quark.

`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 stroe the detail quark.
`force_detail_quark`�:	`TRUE` forces creation of a GQuark for the detail.
Returns :	Whether the signal name could successfully be parsed and `signal_id_p` and `detail_p` contain valid return values.

g_signal_get_invocation_hint ()

GSignalInvocationHint* g_signal_get_invocation_hint
                                            (gpointer instance);

`instance`�:
Returns :

g_signal_handlers_destroy ()

void        g_signal_handlers_destroy       (gpointer instance);

instance�:

g_signal_type_cclosure_new ()

GClosure*   g_signal_type_cclosure_new      (GType itype,
                                             guint struct_offset);

`itype`�:
`struct_offset`�:
Returns :