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20d4f6da73
2008-07-04 Michael Natterer <mitch@imendio.com> Bug 541208 – Functions to easily install and use signals without class struct slot * gobject.symbols * gsignal.[ch] (g_signal_new_class_handler): the same as _gtk_binding_signal_new(), to install signals with a callback instead of a class struct slot as class closure. The next two functions are C convenience and much easier to use than the generic overriding and chaining APIs which are intended primarily for language bindings: (g_signal_override_class_handler): to override a signal with a callback instead of a class struct slot. (g_signal_chain_from_overridden_handler): to chain up from a signal without class struct slot. The API is similar to g_signal_emit(). svn path=/trunk/; revision=7157
510 lines
20 KiB
C
510 lines
20 KiB
C
/* GObject - GLib Type, Object, Parameter and Signal Library
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* Copyright (C) 2000-2001 Red Hat, Inc.
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*
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* This library is free software; you can redistribute it and/or
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* modify it under the terms of the GNU Lesser General Public
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* License as published by the Free Software Foundation; either
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* version 2 of the License, or (at your option) any later version.
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*
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* This library is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
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* Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General
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* Public License along with this library; if not, write to the
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* Free Software Foundation, Inc., 59 Temple Place, Suite 330,
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* Boston, MA 02111-1307, USA.
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*/
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#if !defined (__GLIB_GOBJECT_H_INSIDE__) && !defined (GOBJECT_COMPILATION)
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#error "Only <glib-object.h> can be included directly."
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#endif
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#ifndef __G_SIGNAL_H__
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#define __G_SIGNAL_H__
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#include <gobject/gclosure.h>
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#include <gobject/gvalue.h>
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#include <gobject/gparam.h>
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#include <gobject/gmarshal.h>
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G_BEGIN_DECLS
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/* --- typedefs --- */
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typedef struct _GSignalQuery GSignalQuery;
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typedef struct _GSignalInvocationHint GSignalInvocationHint;
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/**
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* GSignalCMarshaller:
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*
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* This is the signature of marshaller functions, required to marshall
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* arrays of parameter values to signal emissions into C language callback
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* invocations. It is merely an alias to #GClosureMarshal since the #GClosure
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* mechanism takes over responsibility of actual function invocation for the
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* signal system.
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*/
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typedef GClosureMarshal GSignalCMarshaller;
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/**
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* GSignalEmissionHook:
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* @ihint: Signal invocation hint, see #GSignalInvocationHint.
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* @n_param_values: the number of parameters to the function, including
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* the instance on which the signal was emitted.
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* @param_values: the instance on which the signal was emitted, followed by the
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* parameters of the emission.
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* @data: user data associated with the hook.
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*
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* A simple function pointer to get invoked when the signal is emitted. This
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* allows you to tie a hook to the signal type, so that it will trap all
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* emissions of that signal, from any object.
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*
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* You may not attach these to signals created with the #G_SIGNAL_NO_HOOKS flag.
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*
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* Returns: whether it wants to stay connected. If it returns %FALSE, the signal
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* hook is disconnected (and destroyed).
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*/
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typedef gboolean (*GSignalEmissionHook) (GSignalInvocationHint *ihint,
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guint n_param_values,
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const GValue *param_values,
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gpointer data);
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/**
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* GSignalAccumulator:
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* @ihint: Signal invocation hint, see #GSignalInvocationHint.
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* @return_accu: Accumulator to collect callback return values in, this
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* is the return value of the current signal emission.
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* @handler_return: A #GValue holding the return value of the signal handler.
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* @data: Callback data that was specified when creating the signal.
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*
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* The signal accumulator is a special callback function that can be used
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* to collect return values of the various callbacks that are called
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* during a signal emission. The signal accumulator is specified at signal
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* creation time, if it is left %NULL, no accumulation of callback return
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* values is performed. The return value of signal emissions is then the
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* value returned by the last callback.
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*
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* Returns: The accumulator function returns whether the signal emission
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* should be aborted. Returning %FALSE means to abort the
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* current emission and %TRUE is returned for continuation.
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*/
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typedef gboolean (*GSignalAccumulator) (GSignalInvocationHint *ihint,
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GValue *return_accu,
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const GValue *handler_return,
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gpointer data);
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/* --- run, match and connect types --- */
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/**
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* GSignalFlags:
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* @G_SIGNAL_RUN_FIRST: Invoke the object method handler in the first emission stage.
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* @G_SIGNAL_RUN_LAST: Invoke the object method handler in the third emission stage.
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* @G_SIGNAL_RUN_CLEANUP: Invoke the object method handler in the last emission stage.
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* @G_SIGNAL_NO_RECURSE: Signals being emitted for an object while currently being in
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* emission for this very object will not be emitted recursively,
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* but instead cause the first emission to be restarted.
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* @G_SIGNAL_DETAILED: This signal supports "::detail" appendices to the signal name
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* upon handler connections and emissions.
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* @G_SIGNAL_ACTION: Action signals are signals that may freely be emitted on alive
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* objects from user code via g_signal_emit() and friends, without
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* the need of being embedded into extra code that performs pre or
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* post emission adjustments on the object. They can also be thought
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* of as object methods which can be called generically by
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* third-party code.
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* @G_SIGNAL_NO_HOOKS: No emissions hooks are supported for this signal.
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*
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* The signal flags are used to specify a signal's behaviour, the overall
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* signal description outlines how especially the RUN flags control the
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* stages of a signal emission.
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*/
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typedef enum
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{
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G_SIGNAL_RUN_FIRST = 1 << 0,
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G_SIGNAL_RUN_LAST = 1 << 1,
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G_SIGNAL_RUN_CLEANUP = 1 << 2,
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G_SIGNAL_NO_RECURSE = 1 << 3,
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G_SIGNAL_DETAILED = 1 << 4,
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G_SIGNAL_ACTION = 1 << 5,
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G_SIGNAL_NO_HOOKS = 1 << 6
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} GSignalFlags;
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/**
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* G_SIGNAL_FLAGS_MASK:
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*
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* A mask for all #GSignalFlags bits.
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*/
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#define G_SIGNAL_FLAGS_MASK 0x7f
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/**
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* GConnectFlags:
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* @G_CONNECT_AFTER: whether the handler should be called before or after the
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* default handler of the signal.
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* @G_CONNECT_SWAPPED: whether the instance and data should be swapped when
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* calling the handler.
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*
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* The connection flags are used to specify the behaviour of a signal's
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* connection.
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*/
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typedef enum
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{
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G_CONNECT_AFTER = 1 << 0,
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G_CONNECT_SWAPPED = 1 << 1
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} GConnectFlags;
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/**
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* GSignalMatchType:
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* @G_SIGNAL_MATCH_ID: The signal id must be equal.
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* @G_SIGNAL_MATCH_DETAIL: The signal detail be equal.
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* @G_SIGNAL_MATCH_CLOSURE: The closure must be the same.
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* @G_SIGNAL_MATCH_FUNC: The C closure callback must be the same.
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* @G_SIGNAL_MATCH_DATA: The closure data must be the same.
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* @G_SIGNAL_MATCH_UNBLOCKED: Only unblocked signals may matched.
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*
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* The match types specify what g_signal_handlers_block_matched(),
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* g_signal_handlers_unblock_matched() and g_signal_handlers_disconnect_matched()
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* match signals by.
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*/
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typedef enum
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{
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G_SIGNAL_MATCH_ID = 1 << 0,
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G_SIGNAL_MATCH_DETAIL = 1 << 1,
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G_SIGNAL_MATCH_CLOSURE = 1 << 2,
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G_SIGNAL_MATCH_FUNC = 1 << 3,
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G_SIGNAL_MATCH_DATA = 1 << 4,
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G_SIGNAL_MATCH_UNBLOCKED = 1 << 5
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} GSignalMatchType;
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/**
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* G_SIGNAL_MATCH_MASK:
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*
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* A mask for all #GSignalMatchType bits.
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*/
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#define G_SIGNAL_MATCH_MASK 0x3f
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/**
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* G_SIGNAL_TYPE_STATIC_SCOPE:
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*
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* This macro flags signal argument types for which the signal system may
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* assume that instances thereof remain persistent across all signal emissions
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* they are used in. This is only useful for non ref-counted, value-copy types.
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*
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* To flag a signal argument in this way, add
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* <literal>| G_SIGNAL_TYPE_STATIC_SCOPE</literal> to the corresponding argument
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* of g_signal_new().
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* |[
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* g_signal_new ("size_request",
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* G_TYPE_FROM_CLASS (gobject_class),
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* G_SIGNAL_RUN_FIRST,
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* G_STRUCT_OFFSET (GtkWidgetClass, size_request),
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* NULL, NULL,
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* _gtk_marshal_VOID__BOXED,
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* G_TYPE_NONE, 1,
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* GTK_TYPE_REQUISITION | G_SIGNAL_TYPE_STATIC_SCOPE);
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* ]|
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*/
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#define G_SIGNAL_TYPE_STATIC_SCOPE (G_TYPE_FLAG_RESERVED_ID_BIT)
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/* --- signal information --- */
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/**
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* GSignalInvocationHint:
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* @signal_id: The signal id of the signal invoking the callback
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* @detail: The detail passed on for this emission
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* @run_type: The stage the signal emission is currently in, this
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* field will contain one of %G_SIGNAL_RUN_FIRST,
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* %G_SIGNAL_RUN_LAST or %G_SIGNAL_RUN_CLEANUP.
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*
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* The #GSignalInvocationHint structure is used to pass on additional information
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* to callbacks during a signal emission.
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*/
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struct _GSignalInvocationHint
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{
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guint signal_id;
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GQuark detail;
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GSignalFlags run_type;
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};
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/**
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* GSignalQuery:
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* @signal_id: The signal id of the signal being queried, or 0 if the
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* signal to be queried was unknown.
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* @signal_name: The signal name.
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* @itype: The interface/instance type that this signal can be emitted for.
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* @signal_flags: The signal flags as passed in to g_signal_new().
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* @return_type: The return type for user callbacks.
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* @n_params: The number of parameters that user callbacks take.
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* @param_types: The individual parameter types for user callbacks, note that the
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* effective callback signature is:
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* <programlisting>
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* @return_type callback (#gpointer data1,
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* [#param_types param_names,]
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* #gpointer data2);
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* </programlisting>
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*
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* A structure holding in-depth information for a specific signal. It is
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* filled in by the g_signal_query() function.
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*/
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struct _GSignalQuery
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{
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guint signal_id;
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const gchar *signal_name;
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GType itype;
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GSignalFlags signal_flags;
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GType return_type; /* mangled with G_SIGNAL_TYPE_STATIC_SCOPE flag */
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guint n_params;
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const GType *param_types; /* mangled with G_SIGNAL_TYPE_STATIC_SCOPE flag */
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};
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/* --- signals --- */
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guint g_signal_newv (const gchar *signal_name,
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GType itype,
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GSignalFlags signal_flags,
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GClosure *class_closure,
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GSignalAccumulator accumulator,
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gpointer accu_data,
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GSignalCMarshaller c_marshaller,
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GType return_type,
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guint n_params,
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GType *param_types);
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guint g_signal_new_valist (const gchar *signal_name,
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GType itype,
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GSignalFlags signal_flags,
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GClosure *class_closure,
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GSignalAccumulator accumulator,
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gpointer accu_data,
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GSignalCMarshaller c_marshaller,
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GType return_type,
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guint n_params,
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va_list args);
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guint g_signal_new (const gchar *signal_name,
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GType itype,
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GSignalFlags signal_flags,
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guint class_offset,
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GSignalAccumulator accumulator,
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gpointer accu_data,
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GSignalCMarshaller c_marshaller,
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GType return_type,
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guint n_params,
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...);
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guint g_signal_new_class_handler (const gchar *signal_name,
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GType itype,
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GSignalFlags signal_flags,
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GCallback class_handler,
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GSignalAccumulator accumulator,
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gpointer accu_data,
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GSignalCMarshaller c_marshaller,
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GType return_type,
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guint n_params,
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...);
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void g_signal_emitv (const GValue *instance_and_params,
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guint signal_id,
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GQuark detail,
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GValue *return_value);
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void g_signal_emit_valist (gpointer instance,
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guint signal_id,
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GQuark detail,
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va_list var_args);
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void g_signal_emit (gpointer instance,
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guint signal_id,
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GQuark detail,
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...);
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void g_signal_emit_by_name (gpointer instance,
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const gchar *detailed_signal,
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...);
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guint g_signal_lookup (const gchar *name,
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GType itype);
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G_CONST_RETURN gchar* g_signal_name (guint signal_id);
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void g_signal_query (guint signal_id,
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GSignalQuery *query);
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guint* g_signal_list_ids (GType itype,
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guint *n_ids);
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gboolean g_signal_parse_name (const gchar *detailed_signal,
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GType itype,
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guint *signal_id_p,
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GQuark *detail_p,
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gboolean force_detail_quark);
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GSignalInvocationHint* g_signal_get_invocation_hint (gpointer instance);
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/* --- signal emissions --- */
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void g_signal_stop_emission (gpointer instance,
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guint signal_id,
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GQuark detail);
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void g_signal_stop_emission_by_name (gpointer instance,
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const gchar *detailed_signal);
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gulong g_signal_add_emission_hook (guint signal_id,
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GQuark detail,
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GSignalEmissionHook hook_func,
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gpointer hook_data,
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GDestroyNotify data_destroy);
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void g_signal_remove_emission_hook (guint signal_id,
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gulong hook_id);
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/* --- signal handlers --- */
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gboolean g_signal_has_handler_pending (gpointer instance,
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guint signal_id,
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GQuark detail,
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gboolean may_be_blocked);
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gulong g_signal_connect_closure_by_id (gpointer instance,
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guint signal_id,
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GQuark detail,
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GClosure *closure,
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gboolean after);
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gulong g_signal_connect_closure (gpointer instance,
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const gchar *detailed_signal,
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GClosure *closure,
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gboolean after);
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gulong g_signal_connect_data (gpointer instance,
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const gchar *detailed_signal,
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GCallback c_handler,
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gpointer data,
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GClosureNotify destroy_data,
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GConnectFlags connect_flags);
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void g_signal_handler_block (gpointer instance,
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gulong handler_id);
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void g_signal_handler_unblock (gpointer instance,
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gulong handler_id);
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void g_signal_handler_disconnect (gpointer instance,
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gulong handler_id);
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gboolean g_signal_handler_is_connected (gpointer instance,
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gulong handler_id);
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gulong g_signal_handler_find (gpointer instance,
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GSignalMatchType mask,
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guint signal_id,
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GQuark detail,
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GClosure *closure,
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gpointer func,
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gpointer data);
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guint g_signal_handlers_block_matched (gpointer instance,
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GSignalMatchType mask,
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guint signal_id,
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GQuark detail,
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GClosure *closure,
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gpointer func,
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gpointer data);
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guint g_signal_handlers_unblock_matched (gpointer instance,
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GSignalMatchType mask,
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guint signal_id,
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GQuark detail,
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GClosure *closure,
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gpointer func,
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gpointer data);
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guint g_signal_handlers_disconnect_matched (gpointer instance,
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GSignalMatchType mask,
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guint signal_id,
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GQuark detail,
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GClosure *closure,
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gpointer func,
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gpointer data);
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/* --- overriding and chaining --- */
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void g_signal_override_class_closure (guint signal_id,
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GType instance_type,
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GClosure *class_closure);
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void g_signal_override_class_handler (const gchar *signal_name,
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GType instance_type,
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GCallback class_handler);
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void g_signal_chain_from_overridden (const GValue *instance_and_params,
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GValue *return_value);
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void g_signal_chain_from_overridden_handler (gpointer instance,
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...);
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/* --- convenience --- */
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/**
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* g_signal_connect:
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* @instance: the instance to connect to.
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* @detailed_signal: a string of the form "signal-name::detail".
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* @c_handler: the #GCallback to connect.
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* @data: data to pass to @c_handler calls.
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*
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* Connects a #GCallback function to a signal for a particular object.
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*
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* The handler will be called before the default handler of the signal.
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*
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* Returns: the handler id
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*/
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#define g_signal_connect(instance, detailed_signal, c_handler, data) \
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g_signal_connect_data ((instance), (detailed_signal), (c_handler), (data), NULL, (GConnectFlags) 0)
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/**
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* g_signal_connect_after:
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* @instance: the instance to connect to.
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* @detailed_signal: a string of the form "signal-name::detail".
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* @c_handler: the #GCallback to connect.
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* @data: data to pass to @c_handler calls.
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*
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* Connects a #GCallback function to a signal for a particular object.
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*
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* The handler will be called after the default handler of the signal.
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*
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* Returns: the handler id
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*/
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#define g_signal_connect_after(instance, detailed_signal, c_handler, data) \
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g_signal_connect_data ((instance), (detailed_signal), (c_handler), (data), NULL, G_CONNECT_AFTER)
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/**
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* g_signal_connect_swapped:
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* @instance: the instance to connect to.
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* @detailed_signal: a string of the form "signal-name::detail".
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* @c_handler: the #GCallback to connect.
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* @data: data to pass to @c_handler calls.
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*
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* Connects a #GCallback function to a signal for a particular object.
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*
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* The instance on which the signal is emitted and @data will be swapped when
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* calling the handler.
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*
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* Returns: the handler id
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*/
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#define g_signal_connect_swapped(instance, detailed_signal, c_handler, data) \
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g_signal_connect_data ((instance), (detailed_signal), (c_handler), (data), NULL, G_CONNECT_SWAPPED)
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/**
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* g_signal_handlers_disconnect_by_func:
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* @instance: The instance to remove handlers from.
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* @func: The C closure callback of the handlers (useless for non-C closures).
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* @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))
|
|
|
|
|
|
gboolean g_signal_accumulator_true_handled (GSignalInvocationHint *ihint,
|
|
GValue *return_accu,
|
|
const GValue *handler_return,
|
|
gpointer dummy);
|
|
|
|
/*< private >*/
|
|
void g_signal_handlers_destroy (gpointer instance);
|
|
void _g_signals_destroy (GType itype);
|
|
|
|
G_END_DECLS
|
|
|
|
#endif /* __G_SIGNAL_H__ */
|