glib/gobject/gsignal.h
changeset 18 47c74d1534e1
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/glib/gobject/gsignal.h	Fri Apr 16 16:46:38 2010 +0300
@@ -0,0 +1,509 @@
+/* GObject - GLib Type, Object, Parameter and Signal Library
+ * Copyright (C) 2000-2001 Red Hat, Inc.
+ * Portions copyright (c) 2006-2009 Nokia Corporation.  All rights reserved.
+ * 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.
+ */
+#if !defined (__GLIB_GOBJECT_H_INSIDE__) && !defined (GOBJECT_COMPILATION)
+#error "Only <glib-object.h> can be included directly."
+#endif
+
+#ifndef __G_SIGNAL_H__
+#define __G_SIGNAL_H__
+
+#include	<gobject/gclosure.h>
+#include	<gobject/gvalue.h>
+#include	<gobject/gparam.h>
+#include	<gobject/gmarshal.h>
+
+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,
+					 gpointer               data);
+
+
+/* --- 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,
+  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;
+/**
+ * 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,
+  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;
+/**
+ * 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;
+  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 */
+};
+
+
+/* --- signals --- */
+IMPORT_C 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);
+IMPORT_C 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);
+IMPORT_C 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,
+					     ...);
+IMPORT_C 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,
+                                             ...);
+
+IMPORT_C void                  g_signal_emitv        (const GValue       *instance_and_params,
+					     guint               signal_id,
+					     GQuark              detail,
+					     GValue             *return_value);
+IMPORT_C void                  g_signal_emit_valist  (gpointer            instance,
+					     guint               signal_id,
+					     GQuark              detail,
+					     va_list             var_args);
+IMPORT_C void                  g_signal_emit         (gpointer            instance,
+					     guint               signal_id,
+					     GQuark              detail,
+					     ...);
+IMPORT_C void                  g_signal_emit_by_name (gpointer            instance,
+					     const gchar        *detailed_signal,
+					     ...);
+IMPORT_C guint                 g_signal_lookup       (const gchar        *name,
+					     GType               itype);
+IMPORT_C G_CONST_RETURN gchar* g_signal_name         (guint               signal_id);
+IMPORT_C void                  g_signal_query        (guint               signal_id,
+					     GSignalQuery       *query);
+IMPORT_C guint*                g_signal_list_ids     (GType               itype,
+					     guint              *n_ids);
+IMPORT_C gboolean	      g_signal_parse_name   (const gchar	*detailed_signal,
+					     GType		 itype,
+					     guint		*signal_id_p,
+					     GQuark		*detail_p,
+					     gboolean		 force_detail_quark);
+IMPORT_C GSignalInvocationHint* g_signal_get_invocation_hint (gpointer    instance);
+
+
+/* --- signal emissions --- */
+IMPORT_C void	g_signal_stop_emission		    (gpointer		  instance,
+					     guint		  signal_id,
+					     GQuark		  detail);
+IMPORT_C void	g_signal_stop_emission_by_name	    (gpointer		  instance,
+					     const gchar	 *detailed_signal);
+IMPORT_C gulong	g_signal_add_emission_hook	    (guint		  signal_id,
+					     GQuark		  detail,
+					     GSignalEmissionHook  hook_func,
+					     gpointer	       	  hook_data,
+					     GDestroyNotify	  data_destroy);
+IMPORT_C void	g_signal_remove_emission_hook	    (guint		  signal_id,
+					     gulong		  hook_id);
+
+
+/* --- signal handlers --- */
+IMPORT_C gboolean g_signal_has_handler_pending	      (gpointer		  instance,
+					       guint		  signal_id,
+					       GQuark		  detail,
+					       gboolean		  may_be_blocked);
+IMPORT_C gulong	 g_signal_connect_closure_by_id	      (gpointer		  instance,
+					       guint		  signal_id,
+					       GQuark		  detail,
+					       GClosure		 *closure,
+					       gboolean		  after);
+IMPORT_C gulong	 g_signal_connect_closure	      (gpointer		  instance,
+					       const gchar       *detailed_signal,
+					       GClosure		 *closure,
+					       gboolean		  after);
+IMPORT_C gulong	 g_signal_connect_data		      (gpointer		  instance,
+					       const gchar	 *detailed_signal,
+					       GCallback	  c_handler,
+					       gpointer		  data,
+					       GClosureNotify	  destroy_data,
+					       GConnectFlags	  connect_flags);
+IMPORT_C void	 g_signal_handler_block		      (gpointer		  instance,
+					       gulong		  handler_id);
+IMPORT_C void	 g_signal_handler_unblock	      (gpointer		  instance,
+					       gulong		  handler_id);
+IMPORT_C void	 g_signal_handler_disconnect	      (gpointer		  instance,
+					       gulong		  handler_id);
+IMPORT_C gboolean g_signal_handler_is_connected	      (gpointer		  instance,
+					       gulong		  handler_id);
+IMPORT_C gulong	 g_signal_handler_find		      (gpointer		  instance,
+					       GSignalMatchType	  mask,
+					       guint		  signal_id,
+					       GQuark		  detail,
+					       GClosure		 *closure,
+					       gpointer		  func,
+					       gpointer		  data);
+IMPORT_C guint	 g_signal_handlers_block_matched      (gpointer		  instance,
+					       GSignalMatchType	  mask,
+					       guint		  signal_id,
+					       GQuark		  detail,
+					       GClosure		 *closure,
+					       gpointer		  func,
+					       gpointer		  data);
+IMPORT_C guint	 g_signal_handlers_unblock_matched    (gpointer		  instance,
+					       GSignalMatchType	  mask,
+					       guint		  signal_id,
+					       GQuark		  detail,
+					       GClosure		 *closure,
+					       gpointer		  func,
+					       gpointer		  data);
+IMPORT_C guint	 g_signal_handlers_disconnect_matched (gpointer		  instance,
+					       GSignalMatchType	  mask,
+					       guint		  signal_id,
+					       GQuark		  detail,
+					       GClosure		 *closure,
+					       gpointer		  func,
+					       gpointer		  data);
+
+
+/* --- overriding and chaining --- */
+IMPORT_C void    g_signal_override_class_closure       (guint              signal_id,
+                                               GType              instance_type,
+                                               GClosure          *class_closure);
+IMPORT_C void    g_signal_override_class_handler       (const gchar       *signal_name,
+                                               GType              instance_type,
+                                               GCallback          class_handler);
+IMPORT_C void    g_signal_chain_from_overridden        (const GValue      *instance_and_params,
+                                               GValue            *return_value);
+IMPORT_C void   g_signal_chain_from_overridden_handler (gpointer           instance,
+                                               ...);
+
+
+/* --- 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),	\
+				          0, 0, NULL, (func), (data))
+
+
+IMPORT_C gboolean g_signal_accumulator_true_handled (GSignalInvocationHint *ihint,
+					    GValue                *return_accu,
+					    const GValue          *handler_return,
+					    gpointer               dummy);
+
+/*< private >*/
+IMPORT_C void	 g_signal_handlers_destroy	      (gpointer		  instance);
+void	 _g_signals_destroy		      (GType		  itype);
+
+G_END_DECLS
+
+#endif /* __G_SIGNAL_H__ */