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gobject: Add GBinding

Browse Source 
GBinding is a simple, opaque object that represents a binding between a
property on a GObject instance (source) and property on another GObject
instance (target).

https://bugzilla.gnome.org/show_bug.cgi?id=348080
This commit is contained in:
Emmanuele Bassi 2010-06-04 16:17:15 +01:00
parent f3879a4bdc
commit 6d1d9cf1b5
11 changed files with 1430 additions and 3 deletions
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1
docs/reference/gobject/gobject-docs.sgml
View File

@ -83,6 +83,7 @@
<xi:include href="xml/signals.xml" />
<xi:include href="xml/gclosure.xml" />
<xi:include href="xml/value_arrays.xml" />
<xi:include href="xml/gbinding.xml" />
</reference>
<reference label="III">
<title>Tools Reference</title>

23
docs/reference/gobject/gobject-sections.txt
View File

@ -839,3 +839,26 @@ g_closure_get_type
g_io_channel_get_type
g_io_condition_get_type
</SECTION>
<SECTION>
<FILE>gbinding</FILE>
GBinding
GBindingFlags
g_binding_get_source
g_binding_get_source_property
g_binding_get_target
g_binding_get_target_property
g_binding_get_flags
<SUBSECTION>
g_object_bind_property
GBindingTransformFunc
g_object_bind_property_full
<SUBSECTION Standard>
G_TYPE_BINDING
G_TYPE_BINDING_FLAGS
G_BINDING
G_IS_BINDING
<SUBSECTION Private>
g_binding_flags_get_type
g_binding_get_type
</SECTION>

1
docs/reference/gobject/gobject.types
View File

@ -1,6 +1,7 @@
#include <glib/glib-object.h>
#include "gobject.cI"
g_binding_get_type
g_object_get_type
g_type_module_get_type
g_type_plugin_get_type

1
glib/glib-object.h
View File

@ -22,6 +22,7 @@
#define __GLIB_GOBJECT_H_INSIDE__
/* topmost include file for GObject header files */
#include <gobject/gbinding.h>
#include <gobject/gboxed.h>
#include <gobject/genums.h>
#include <gobject/gobject.h>

5
gobject/Makefile.am
View File

@ -97,6 +97,7 @@ libgobject_2_0_la_DEPENDENCIES = $(gobject_win32_res) $(gobject_def)
#
# GObject library header files for public installation
gobject_public_h_sources = \
gbinding.h \
gboxed.h \
gclosure.h \
genums.h \
@ -124,6 +125,7 @@ gobject_private_h_sources = \
gobject_c_sources = \
gobject_probes.d \
gatomicarray.c \
gbinding.c \
gboxed.c \
gclosure.c \
genums.c \
@ -188,7 +190,7 @@ EXTRA_DIST += \
#
# setup autogeneration dependancies
gen_sources = xgen-gmh xgen-gmc xgen-gms
CLEANFILES = $(gen_sources)
CLEANFILES += $(gen_sources)
# normal autogeneration rules
# all autogenerated files need to be generated in the srcdir,
@ -229,7 +231,6 @@ gmarshal.strings: @REBUILD@ $(srcdir)/gmarshal.list
glib-genmarshal.o: gmarshal.strings
gsignal.lo: gmarshal.c
# target platform:
libgobjectinclude_HEADERS = $(gobject_target_headers)
libgobject_2_0_la_SOURCES = $(gobject_target_sources)

937
gobject/gbinding.c Normal file
View File

@ -0,0 +1,937 @@
/* gbinding.c: Binding for object properties
*
* Copyright (C) 2010 Intel Corp.
*
* 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.
*
* Author: Emmanuele Bassi <ebassi@linux.intel.com>
*/
/**
* SECTION:gbinding
* @Title: GBinding
* @Short_Description: Bind two object properties
*
* #GBinding is the representation of a binding between a property on a
* #GObject instance (or source) and another property on another #GObject
* instance (or target). Whenever the source property changes, the same
* value is applied to the target property; for instance, the following
* binding:
*
* |[
* g_object_bind_property (object1, "property-a",
* object2, "property-b",
* G_BINDING_DEFAULT);
* ]|
*
* will cause <emphasis>object2:property-b</emphasis> to be updated every
* time g_object_set() or the specific accessor changes the value of
* <emphasis>object1:property-a</emphasis>.
*
* It is possible to create a bidirectional binding between two properties
* of two #GObject instances, so that if either property changes, the
* other is updated as well, for instance:
*
* |[
* g_object_bind_property (object1, "property-a",
* object2, "property-b",
* G_BINDING_BIDIRECTIONAL);
* ]|
*
* will keep the two properties in sync.
*
* It is also possible to set a custom transformation function (in both
* directions, in case of a bidirectional binding) to apply a custom
* transformation from the source value to the target value before
* applying it; for instance, the following binding:
*
* |[
* g_object_bind_property_full (adjustment1, "value",
* adjustment2, "value",
* G_BINDING_BIDIRECTIONAL,
* celsius_to_fahrenheit,
* fahrenheit_to_celsius,
* NULL, NULL);
* ]|
*
* will keep the <emphasis>value</emphasis> property of the two adjustments
* in sync; the <function>celsius_to_fahrenheit</function> function will be
* called whenever the <emphasis>adjustment1:value</emphasis> property changes
* and will transform the current value of the property before applying it
* to the <emphasis>adjustment2:value</emphasis> property; vice versa, the
* <function>fahrenheit_to_celsius</function> function will be called whenever
* the <emphasis>adjustment2:value</emphasis> property changes, and will
* transform the current value of the property before applying it to the
* <emphasis>adjustment1:value</emphasis>.
*
* Note that #GBinding does not resolve cycles by itself; a cycle like
*
* |[
* object1:propertyA -> object2:propertyB
* object2:propertyB -> object3:propertyC
* object3:propertyC -> object1:propertyA
* ]|
*
* might lead to an infinite loop. The loop, in this particular case,
* can be avoided if the objects emit the #GObject::notify signal only
* if the value has effectively been changed. A binding is implemented
* using the #GObject::notify signal, so it is susceptible to all the
* various ways of blocking a signal emission, like g_signal_stop_emission()
* or g_signal_handler_block().
*
* A binding will be severed, and the resources it allocates freed, whenever
* either one of the #GObject instances it refers to are finalized, or when
* the #GBinding instance loses its last reference.
*
* #GBinding is available since GObject 2.26
*/
#include "config.h"
#include <string.h>
#include "gbinding.h"
#include "genums.h"
#include "gobject.h"
#include "gsignal.h"
#include "gparamspecs.h"
#include "gvaluetypes.h"
#include "glibintl.h"
#include "gobjectalias.h"
GType
g_binding_flags_get_type (void)
{
static volatile gsize g_define_type_id__volatile = 0;
if (g_once_init_enter (&g_define_type_id__volatile))
{
static const GFlagsValue values[] = {
{ G_BINDING_DEFAULT, "G_BINDING_DEFAULT", "default" },
{ G_BINDING_BIDIRECTIONAL, "G_BINDING_BIDIRECTIONAL", "bidirectional" },
{ 0, NULL, NULL }
};
GType g_define_type_id =
g_flags_register_static (g_intern_static_string ("GBindingFlags"), values);
g_once_init_leave (&g_define_type_id__volatile, g_define_type_id);
}
return g_define_type_id__volatile;
}
#define G_BINDING_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), G_TYPE_BINDING, GBindingClass))
#define G_IS_BINDING_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), G_TYPE_BINDING))
#define G_BINDING_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), G_TYPE_BINDING, GBindingClass))
typedef struct _GBindingClass GBindingClass;
struct _GBinding
{
GObject parent_instance;
/* no reference is held on the objects, to avoid cycles */
GObject *source;
GObject *target;
/* the property names are interned, so they should not be freed */
gchar *source_property;
gchar *target_property;
GParamSpec *source_pspec;
GParamSpec *target_pspec;
GBindingTransformFunc transform_s2t;
GBindingTransformFunc transform_t2s;
GBindingFlags flags;
guint source_notify;
guint target_notify;
gpointer transform_data;
GDestroyNotify notify;
/* a guard, to avoid loops */
guint is_frozen : 1;
};
struct _GBindingClass
{
GObjectClass parent_class;
};
enum
{
PROP_0,
PROP_SOURCE,
PROP_TARGET,
PROP_SOURCE_PROPERTY,
PROP_TARGET_PROPERTY,
PROP_FLAGS
};
static GQuark quark_gbinding = 0;
G_DEFINE_TYPE (GBinding, g_binding, G_TYPE_OBJECT);
static inline void
add_binding_qdata (GObject *gobject,
GBinding *binding)
{
GList *bindings;
bindings = g_object_get_qdata (gobject, quark_gbinding);
if (bindings == NULL)
{
bindings = g_list_prepend (NULL, binding);
g_object_set_qdata (gobject, quark_gbinding, bindings);
}
else
bindings = g_list_prepend (bindings, binding);
}
static inline void
remove_binding_qdata (GObject *gobject,
GBinding *binding)
{
GList *bindings;
bindings = g_object_get_qdata (gobject, quark_gbinding);
bindings = g_list_remove (bindings, binding);
}
static void
weak_unbind (gpointer user_data,
GObject *where_the_object_was)
{
GBinding *binding = user_data;
if (binding->source == where_the_object_was)
binding->source = NULL;
else
{
if (binding->source_notify != 0)
g_signal_handler_disconnect (binding->source, binding->source_notify);
g_object_weak_unref (binding->source, weak_unbind, user_data);
remove_binding_qdata (binding->source, binding);
binding->source = NULL;
}
if (binding->target == where_the_object_was)
binding->target = NULL;
else
{
if (binding->target_notify != 0)
g_signal_handler_disconnect (binding->target, binding->target_notify);
g_object_weak_unref (binding->target, weak_unbind, user_data);
remove_binding_qdata (binding->target, binding);
binding->target = NULL;
}
g_object_unref (binding);
}
static inline gboolean
default_transform (const GValue *value_a,
GValue *value_b)
{
/* if it's not the same type, try to convert it using the GValue
* transformation API; otherwise just copy it
*/
if (!g_type_is_a (G_VALUE_TYPE (value_a), G_VALUE_TYPE (value_b)))
{
/* are these two types compatible (can be directly copied)? */
if (g_value_type_compatible (G_VALUE_TYPE (value_a),
G_VALUE_TYPE (value_b)))
{
g_value_copy (value_a, value_b);
goto done;
}
if (g_value_type_transformable (G_VALUE_TYPE (value_a),
G_VALUE_TYPE (value_b)))
{
if (g_value_transform (value_a, value_b))
goto done;
g_warning ("%s: Unable to convert a value of type %s to a "
"value of type %s",
G_STRLOC,
g_type_name (G_VALUE_TYPE (value_a)),
g_type_name (G_VALUE_TYPE (value_b)));
return FALSE;
}
}
else
g_value_copy (value_a, value_b);
done:
return TRUE;
}
static gboolean
default_transform_to (GBinding *binding G_GNUC_UNUSED,
const GValue *value_a,
GValue *value_b,
gpointer user_data G_GNUC_UNUSED)
{
return default_transform (value_a, value_b);
}
static gboolean
default_transform_from (GBinding *binding G_GNUC_UNUSED,
const GValue *value_a,
GValue *value_b,
gpointer user_data G_GNUC_UNUSED)
{
return default_transform (value_a, value_b);
}
static void
on_source_notify (GObject *gobject,
GParamSpec *pspec,
GBinding *binding)
{
const gchar *p_name;
GValue source_value = { 0, };
GValue target_value = { 0, };
gboolean res;
if (binding->is_frozen)
return;
if (pspec->flags & G_PARAM_STATIC_NAME)
p_name = g_intern_static_string (pspec->name);
else
p_name = g_intern_string (pspec->name);
if (p_name != binding->source_property)
return;
g_value_init (&source_value, G_PARAM_SPEC_VALUE_TYPE (binding->source_pspec));
g_value_init (&target_value, G_PARAM_SPEC_VALUE_TYPE (binding->target_pspec));
g_object_get_property (binding->source, binding->source_pspec->name, &source_value);
res = binding->transform_s2t (binding,
&source_value,
&target_value,
binding->transform_data);
if (res)
{
binding->is_frozen = TRUE;
g_param_value_validate (binding->target_pspec, &target_value);
g_object_set_property (binding->target, binding->target_pspec->name, &target_value);
binding->is_frozen = FALSE;
}
g_value_unset (&source_value);
g_value_unset (&target_value);
}
static void
on_target_notify (GObject *gobject,
GParamSpec *pspec,
GBinding *binding)
{
const gchar *p_name;
GValue source_value = { 0, };
GValue target_value = { 0, };
gboolean res;
if (binding->is_frozen)
return;
if (pspec->flags & G_PARAM_STATIC_NAME)
p_name = g_intern_static_string (pspec->name);
else
p_name = g_intern_string (pspec->name);
if (p_name != binding->target_property)
return;
g_value_init (&source_value, G_PARAM_SPEC_VALUE_TYPE (binding->target_pspec));
g_value_init (&target_value, G_PARAM_SPEC_VALUE_TYPE (binding->source_pspec));
g_object_get_property (binding->target, binding->target_pspec->name, &source_value);
res = binding->transform_t2s (binding,
&source_value,
&target_value,
binding->transform_data);
if (res)
{
binding->is_frozen = TRUE;
g_param_value_validate (binding->source_pspec, &target_value);
g_object_set_property (binding->source, binding->source_pspec->name, &target_value);
binding->is_frozen = FALSE;
}
g_value_unset (&source_value);
g_value_unset (&target_value);
}
static void
g_binding_finalize (GObject *gobject)
{
GBinding *binding = G_BINDING (gobject);
if (binding->notify != NULL)
{
binding->notify (binding->transform_data);
binding->transform_data = NULL;
binding->notify = NULL;
}
if (binding->source != NULL)
{
if (binding->source_notify != 0)
g_signal_handler_disconnect (binding->source, binding->source_notify);
g_object_weak_unref (binding->source, weak_unbind, binding);
remove_binding_qdata (binding->source, binding);
}
if (binding->target != NULL)
{
if (binding->target_notify != 0)
g_signal_handler_disconnect (binding->target, binding->target_notify);
g_object_weak_unref (binding->target, weak_unbind, binding);
remove_binding_qdata (binding->target, binding);
}
G_OBJECT_CLASS (g_binding_parent_class)->finalize (gobject);
}
static void
g_binding_set_property (GObject *gobject,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
GBinding *binding = G_BINDING (gobject);
switch (prop_id)
{
case PROP_SOURCE:
binding->source = g_value_get_object (value);
break;
case PROP_SOURCE_PROPERTY:
binding->source_property = g_intern_string (g_value_get_string (value));
break;
case PROP_TARGET:
binding->target = g_value_get_object (value);
break;
case PROP_TARGET_PROPERTY:
binding->target_property = g_intern_string (g_value_get_string (value));
break;
case PROP_FLAGS:
binding->flags = g_value_get_flags (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
g_binding_get_property (GObject *gobject,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
GBinding *binding = G_BINDING (gobject);
switch (prop_id)
{
case PROP_SOURCE:
g_value_set_object (value, binding->source);
break;
case PROP_SOURCE_PROPERTY:
g_value_set_string (value, binding->source_property);
break;
case PROP_TARGET:
g_value_set_object (value, binding->target);
break;
case PROP_TARGET_PROPERTY:
g_value_set_string (value, binding->target_property);
break;
case PROP_FLAGS:
g_value_set_flags (value, binding->flags);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
g_binding_constructed (GObject *gobject)
{
GBinding *binding = G_BINDING (gobject);
/* assert that we were constructed correctly */
g_assert (binding->source != NULL);
g_assert (binding->target != NULL);
g_assert (binding->source_property != NULL);
g_assert (binding->target_property != NULL);
/* we assume a check was performed prior to construction - since
* g_object_bind_property_full() does it; we cannot fail construction
* anyway, so it would be hard for use to properly warn here
*/
binding->source_pspec = g_object_class_find_property (G_OBJECT_GET_CLASS (binding->source), binding->source_property);
binding->target_pspec = g_object_class_find_property (G_OBJECT_GET_CLASS (binding->target), binding->target_property);
g_assert (binding->source_pspec != NULL);
g_assert (binding->target_pspec != NULL);
/* set the default transformation functions here */
binding->transform_s2t = default_transform_to;
binding->transform_t2s = default_transform_from;
binding->transform_data = NULL;
binding->notify = NULL;
binding->source_notify = g_signal_connect (binding->source, "notify",
G_CALLBACK (on_source_notify),
binding);
g_object_weak_ref (binding->source, weak_unbind, binding);
add_binding_qdata (binding->source, binding);
if (binding->flags & G_BINDING_BIDIRECTIONAL)
binding->target_notify = g_signal_connect (binding->target, "notify",
G_CALLBACK (on_target_notify),
binding);
g_object_weak_ref (binding->target, weak_unbind, binding);
add_binding_qdata (binding->target, binding);
}
static void
g_binding_class_init (GBindingClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
quark_gbinding = g_quark_from_static_string ("g-binding");
gobject_class->constructed = g_binding_constructed;
gobject_class->set_property = g_binding_set_property;
gobject_class->get_property = g_binding_get_property;
gobject_class->finalize = g_binding_finalize;
/**
* GBinding:source:
*
* The #GObject that should be used as the source of the binding
*
* Since: 2.26
*/
g_object_class_install_property (gobject_class, PROP_SOURCE,
g_param_spec_object ("source",
P_("Source"),
P_("The source of the binding"),
G_TYPE_OBJECT,
G_PARAM_CONSTRUCT_ONLY |
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS));
/**
* GBinding:target:
*
* The #GObject that should be used as the target of the binding
*
* Since: 2.26
*/
g_object_class_install_property (gobject_class, PROP_TARGET,
g_param_spec_object ("target",
P_("Target"),
P_("The target of the binding"),
G_TYPE_OBJECT,
G_PARAM_CONSTRUCT_ONLY |
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS));
/**
* GBinding:source-property:
*
* The name of the property of #GBinding:source that should be used
* as the source of the binding
*
* Since: 2.26
*/
g_object_class_install_property (gobject_class, PROP_SOURCE_PROPERTY,
g_param_spec_string ("source-property",
P_("Source Property"),
P_("The property on the source to bind"),
NULL,
G_PARAM_CONSTRUCT_ONLY |
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS));
/**
* GBinding:target-property:
*
* The name of the property of #GBinding:target that should be used
* as the target of the binding
*
* Since: 2.26
*/
g_object_class_install_property (gobject_class, PROP_TARGET_PROPERTY,
g_param_spec_string ("target-property",
P_("Target Property"),
P_("The property on the target to bind"),
NULL,
G_PARAM_CONSTRUCT_ONLY |
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS));
/**
* GBinding:flags:
*
* Flags to be used to control the #GBinding
*
* Since: 2.26
*/
g_object_class_install_property (gobject_class, PROP_FLAGS,
g_param_spec_flags ("flags",
P_("Flags"),
P_("The binding flags"),
G_TYPE_BINDING_FLAGS,
G_BINDING_DEFAULT,
G_PARAM_CONSTRUCT_ONLY |
G_PARAM_READWRITE |
G_PARAM_STATIC_STRINGS));
}
static void
g_binding_init (GBinding *binding)
{
}
/**
* g_binding_get_flags:
* @binding: a #GBinding
*
* Retrieves the flags passed when constructing the #GBinding
*
* Return value: the #GBindingFlags used by the #GBinding
*
* Since: 2.26
*/
GBindingFlags
g_binding_get_flags (GBinding *binding)
{
g_return_val_if_fail (G_IS_BINDING (binding), G_BINDING_DEFAULT);
return binding->flags;
}
/**
* g_binding_get_source:
* @binding: a #GBinding
*
* Retrieves the #GObject instance used as the source of the binding
*
* Return value: (transfer none): the source #GObject
*
* Since: 2.26
*/
GObject *
g_binding_get_source (GBinding *binding)
{
g_return_val_if_fail (G_IS_BINDING (binding), NULL);
return binding->source;
}
/**
* g_binding_get_target:
* @binding: a #GBinding
*
* Retrieves the #GObject instance used as the target of the binding
*
* Return value: (transfer none): the target #GObject
*
* Since: 2.26
*/
GObject *
g_binding_get_target (GBinding *binding)
{
g_return_val_if_fail (G_IS_BINDING (binding), NULL);
return binding->target;
}
/**
* g_binding_get_source_property:
* @binding: a #GBinding
*
* Retrieves the name of the property of #GBinding:source used as the source
* of the binding
*
* Return value: the name of the source property
*
* Since: 2.26
*/
G_CONST_RETURN gchar *
g_binding_get_source_property (GBinding *binding)
{
g_return_val_if_fail (G_IS_BINDING (binding), NULL);
return binding->source_property;
}
/**
* g_binding_get_target_property:
* @binding: a #GBinding
*
* Retrieves the name of the property of #GBinding:target used as the target
* of the binding
*
* Return value: the name of the target property
*
* Since: 2.26
*/
G_CONST_RETURN gchar *
g_binding_get_target_property (GBinding *binding)
{
g_return_val_if_fail (G_IS_BINDING (binding), NULL);
return binding->target_property;
}
/**
* g_object_bind_property_full:
* @source: the source #GObject
* @source_property: the property on @source to bind
* @target: the target #GObject
* @target_property: the property on @target to bind
* @flags: flags to pass to #GBinding
* @transform_to: (scope notified) (allow-none): the transformation function
* from the @source to the @target, or %NULL to use the default
* @transform_from: (scope notified) (allow-none): the transformation function
* from the @target to the @source, or %NULL to use the default
* @user_data: custom data to be passed to the transformation functions,
* or %NULL
* @notify: function to be called when disposing the binding, to free the
* resources used by the transformation functions
*
* Complete version of g_object_bind_property().
*
* Creates a binding between @source_property on @source and @target_property
* on @target, allowing you to set the transformation functions to be used by
* the binding.
*
* If @flags contains %G_BINDING_BIDIRECTIONAL then the binding will be mutual:
* if @target_property on @target changes then the @source_property on @source
* will be updated as well. The @transform_from function is only used in case
* of bidirectional bindings, otherwise it will be ignored
*
* The binding will automatically be removed when either the @source or the
* @target instances are finalized. To remove the binding without affecting the
* @source and the @target you can just call g_object_unref() on the returned
* #GBinding instance.
*
* A #GObject can have multiple bindings.
*
* Return value: (transfer none): the #GBinding instance representing the
* binding between the two #GObject instances. The binding is released
* whenever the #GBinding reference count reaches zero.
*
* Since: 2.26
*/
GBinding *
g_object_bind_property_full (gpointer source,
const gchar *source_property,
gpointer target,
const gchar *target_property,
GBindingFlags flags,
GBindingTransformFunc transform_to,
GBindingTransformFunc transform_from,
gpointer user_data,
GDestroyNotify notify)
{
GParamSpec *pspec;
GBinding *binding;
g_return_val_if_fail (G_IS_OBJECT (source), NULL);
g_return_val_if_fail (source_property != NULL, NULL);
g_return_val_if_fail (G_IS_OBJECT (target), NULL);
g_return_val_if_fail (target_property != NULL, NULL);
if (source == target && g_strcmp0 (source_property, target_property) == 0)
{
g_warning ("Unable to bind the same property on the same instance");
return NULL;
}
if (transform_to == NULL)
transform_to = default_transform_to;
if (transform_from == NULL)
transform_from = default_transform_from;
pspec = g_object_class_find_property (G_OBJECT_GET_CLASS (source), source_property);
if (pspec == NULL)
{
g_warning ("%s: The source object of type %s has no property called '%s'",
G_STRLOC,
G_OBJECT_TYPE_NAME (source),
source_property);
return NULL;
}
if (!(pspec->flags & G_PARAM_READABLE))
{
g_warning ("%s: The source object of type %s has no readable property called '%s'",
G_STRLOC,
G_OBJECT_TYPE_NAME (source),
source_property);
return NULL;
}
if ((flags & G_BINDING_BIDIRECTIONAL) &&
((pspec->flags & G_PARAM_CONSTRUCT_ONLY) || !(pspec->flags & G_PARAM_WRITABLE)))
{
g_warning ("%s: The source object of type %s has no writable property called '%s'",
G_STRLOC,
G_OBJECT_TYPE_NAME (source),
source_property);
return NULL;
}
pspec = g_object_class_find_property (G_OBJECT_GET_CLASS (target), target_property);
if (pspec == NULL)
{
g_warning ("%s: The target object of type %s has no property called '%s'",
G_STRLOC,
G_OBJECT_TYPE_NAME (target),
target_property);
return NULL;
}
if ((pspec->flags & G_PARAM_CONSTRUCT_ONLY) || !(pspec->flags & G_PARAM_WRITABLE))
{
g_warning ("%s: The target object of type %s has no writable property called '%s'",
G_STRLOC,
G_OBJECT_TYPE_NAME (target),
target_property);
return NULL;
}
if ((flags & G_BINDING_BIDIRECTIONAL) &&
!(pspec->flags & G_PARAM_READABLE))
{
g_warning ("%s: The starget object of type %s has no writable property called '%s'",
G_STRLOC,
G_OBJECT_TYPE_NAME (target),
target_property);
return NULL;
}
binding = g_object_new (G_TYPE_BINDING,
"source", source,
"source-property", source_property,
"target", target,
"target-property", target_property,
"flags", flags,
NULL);
/* making these properties would be awkward, though not impossible */
binding->transform_s2t = transform_to;
binding->transform_t2s = transform_from;
binding->transform_data = user_data;
binding->notify = notify;
return binding;
}
/**
* g_object_bind_property:
* @source: the source #GObject
* @source_property: the property on @source to bind
* @target: the target #GObject
* @target_property: the property on @target to bind
* @flags: flags to pass to #GBinding
*
* Creates a binding between @source_property on @source and @target_property
* on @target. Whenever the @source_property is changed the @target_property is
* updated using the same value. For instance:
*
* |[
* g_object_bind_property (action, "active", widget, "sensitive", 0);
* ]|
*
* Will result in the "sensitive" property of the widget #GObject instance to be
* updated with the same value of the "active" property of the action #GObject
* instance.
*
* If @flags contains %G_BINDING_BIDIRECTIONAL then the binding will be mutual:
* if @target_property on @target changes then the @source_property on @source
* will be updated as well.
*
* The binding will automatically be removed when either the @source or the
* @target instances are finalized. To remove the binding without affecting the
* @source and the @target you can just call g_object_unref() on the returned
* #GBinding instance.
*
* A #GObject can have multiple bindings.
*
* Return value: (transfer none): the #GBinding instance representing the
* binding between the two #GObject instances. The binding is released
* whenever the #GBinding reference count reaches zero.
*
* Since: 2.26
*/
GBinding *
g_object_bind_property (gpointer source,
const gchar *source_property,
gpointer target,
const gchar *target_property,
GBindingFlags flags)
{
/* type checking is done in g_object_bind_property_full() */
return g_object_bind_property_full (source, source_property,
target, target_property,
flags,
NULL,
NULL,
NULL, NULL);
}
#define __G_BINDING_C__
#include "gobjectaliasdef.c"

119
gobject/gbinding.h Normal file
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@ -0,0 +1,119 @@
/* gbinding.h: Binding for object properties
*
* Copyright (C) 2010 Intel Corp.
*
* 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.
*
* Author: Emmanuele Bassi <ebassi@linux.intel.com>
*/
#if !defined (__GLIB_GOBJECT_H_INSIDE__) && !defined (GOBJECT_COMPILATION)
#error "Only <glib-object.h> can be included directly."
#endif
#ifndef __G_BINDING_H__
#define __G_BINDING_H__
#include <glib.h>
#include <gobject/gobject.h>
G_BEGIN_DECLS
#define G_TYPE_BINDING_FLAGS (g_binding_flags_get_type ())
#define G_TYPE_BINDING (g_binding_get_type ())
#define G_BINDING(obj) (G_TYPE_CHECK_INSTANCE_CAST ((obj), G_TYPE_BINDING, GBinding))
#define G_IS_BINDING(obj) (G_TYPE_CHECK_INSTANCE_TYPE ((obj), G_TYPE_BINDING))
/**
* GBinding:
*
* <structname>GBinding</structname> is an opaque structure whose members
* cannot be accessed directly.
*
* Since: 2.26
*/
typedef struct _GBinding GBinding;
/**
* GBindingTransformFunc:
* @binding: a #GBinding
* @source_value: the value of the source property
* @target_value: the value of the target property
* @user_data: data passed to the transform function
*
* A function to be called to transform the source property of @source
* from @source_value into the target property of @target using
* @target_value
*
* Return value: %TRUE if the transformation was successful, and %FALSE
* otherwise
*
* Since: 2.26
*/
typedef gboolean (* GBindingTransformFunc) (GBinding *binding,
const GValue *source_value,
GValue *target_value,
gpointer user_data);
/**
* GBindingFlags:
* @G_BINDING_DEFAULT: The default binding; if the source property
* changes, the target property is updated with its value
* @G_BINDING_BIDIRECTIONAL: Bidirectional binding; if either the
* property of the source or the property of the target changes,
* the other is updated
*
* Flags to be passed to g_object_bind_property() or
* g_object_bind_property_full().
*
* This enumeration can be extended at later date.
*
* Since: 2.26
*/
typedef enum { /*< prefix=G_BINDING >*/
G_BINDING_DEFAULT = 0,
G_BINDING_BIDIRECTIONAL = 1 << 0
} GBindingFlags;
GType g_binding_flags_get_type (void) G_GNUC_CONST;
GType g_binding_get_type (void) G_GNUC_CONST;
GBindingFlags g_binding_get_flags (GBinding *binding);
GObject * g_binding_get_source (GBinding *binding);
GObject * g_binding_get_target (GBinding *binding);
G_CONST_RETURN gchar *g_binding_get_source_property (GBinding *binding);
G_CONST_RETURN gchar *g_binding_get_target_property (GBinding *binding);
GBinding *g_object_bind_property (gpointer source,
const gchar *source_property,
gpointer target,
const gchar *target_property,
GBindingFlags flags);
GBinding *g_object_bind_property_full (gpointer source,
const gchar *source_property,
gpointer target,
const gchar *target_property,
GBindingFlags flags,
GBindingTransformFunc transform_to,
GBindingTransformFunc transform_from,
gpointer user_data,
GDestroyNotify notify);
G_END_DECLS
#endif /* __G_BINDING_H__ */

15
gobject/gobject.symbols
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@ -11,6 +11,21 @@
#define IN_FILE(x) 1
#define IN_HEADER(x) 1
#endif
#if IN_HEADER(__G_BINDING_H__)
#if IN_FILE(__G_BINDING_C__)
g_binding_flags_get_type G_GNUC_CONST
g_binding_get_type G_GNUC_CONST
g_binding_get_flags
g_binding_get_source
g_binding_get_target
g_binding_get_source_property
g_binding_get_target_property
g_object_bind_property
g_object_bind_property_full
#endif
#endif
#if IN_HEADER(__G_BOXED_H__)
#if IN_FILE(__G_BOXED_C__)
g_boxed_copy

1
gobject/tests/.gitignore vendored
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@ -1,2 +1,3 @@
binding
dynamictests
threadtests

4
gobject/tests/Makefile.am
View File

@ -5,8 +5,10 @@ INCLUDES = -g -I$(top_srcdir) -I$(top_srcdir)/glib $(GLIB_DEBUG_FLAGS)
noinst_PROGRAMS = $(TEST_PROGS)
libgobject_LDADD = ../libgobject-2.0.la $(top_builddir)/gthread/libgthread-2.0.la $(top_builddir)/glib/libglib-2.0.la
TEST_PROGS += threadtests dynamictests
TEST_PROGS += threadtests dynamictests binding
threadtests_SOURCES = threadtests.c
threadtests_LDADD = $(libgobject_LDADD)
dynamictests_SOURCES = dynamictests.c
dynamictests_LDADD = $(libgobject_LDADD)
binding_SOURCES = binding.c
binding_LDADD = $(libgobject_LDADD)

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#include <stdlib.h>
#include <gstdio.h>
#include <glib-object.h>
typedef struct _BindingSource
{
GObject parent_instance;
gint foo;
gdouble value;
} BindingSource;
typedef struct _BindingSourceClass
{
GObjectClass parent_class;
} BindingSourceClass;
enum
{
PROP_SOURCE_0,
PROP_SOURCE_FOO,
PROP_SOURCE_VALUE
};
G_DEFINE_TYPE (BindingSource, binding_source, G_TYPE_OBJECT);
static void
binding_source_set_property (GObject *gobject,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
BindingSource *source = (BindingSource *) gobject;
switch (prop_id)
{
case PROP_SOURCE_FOO:
source->foo = g_value_get_int (value);
break;
case PROP_SOURCE_VALUE:
source->value = g_value_get_double (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
}
}
static void
binding_source_get_property (GObject *gobject,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
BindingSource *source = (BindingSource *) gobject;
switch (prop_id)
{
case PROP_SOURCE_FOO:
g_value_set_int (value, source->foo);
break;
case PROP_SOURCE_VALUE:
g_value_set_double (value, source->value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
}
}
static void
binding_source_class_init (BindingSourceClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->set_property = binding_source_set_property;
gobject_class->get_property = binding_source_get_property;
g_object_class_install_property (gobject_class, PROP_SOURCE_FOO,
g_param_spec_int ("foo", "Foo", "Foo",
-1, 100,
0,
G_PARAM_READWRITE));
g_object_class_install_property (gobject_class, PROP_SOURCE_VALUE,
g_param_spec_double ("value", "Value", "Value",
-100.0, 200.0,
0.0,
G_PARAM_READWRITE));
}
static void
binding_source_init (BindingSource *self)
{
}
typedef struct _BindingTarget
{
GObject parent_instance;
gint bar;
gdouble value;
} BindingTarget;
typedef struct _BindingTargetClass
{
GObjectClass parent_class;
} BindingTargetClass;
enum
{
PROP_TARGET_0,
PROP_TARGET_BAR,
PROP_TARGET_VALUE
};
G_DEFINE_TYPE (BindingTarget, binding_target, G_TYPE_OBJECT);
static void
binding_target_set_property (GObject *gobject,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
BindingTarget *target = (BindingTarget *) gobject;
switch (prop_id)
{
case PROP_TARGET_BAR:
target->bar = g_value_get_int (value);
break;
case PROP_TARGET_VALUE:
target->value = g_value_get_double (value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
}
}
static void
binding_target_get_property (GObject *gobject,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
BindingTarget *target = (BindingTarget *) gobject;
switch (prop_id)
{
case PROP_TARGET_BAR:
g_value_set_int (value, target->bar);
break;
case PROP_TARGET_VALUE:
g_value_set_double (value, target->value);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
}
}
static void
binding_target_class_init (BindingTargetClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
gobject_class->set_property = binding_target_set_property;
gobject_class->get_property = binding_target_get_property;
g_object_class_install_property (gobject_class, PROP_TARGET_BAR,
g_param_spec_int ("bar", "Bar", "Bar",
-1, 100,
0,
G_PARAM_READWRITE));
g_object_class_install_property (gobject_class, PROP_SOURCE_VALUE,
g_param_spec_double ("value", "Value", "Value",
-100.0, 200.0,
0.0,
G_PARAM_READWRITE));
}
static void
binding_target_init (BindingTarget *self)
{
}
static gboolean
celsius_to_fahrenheit (GBinding *binding,
const GValue *source_value,
GValue *target_value,
gpointer user_data G_GNUC_UNUSED)
{
gdouble celsius, fahrenheit;
g_assert (G_VALUE_HOLDS (source_value, G_TYPE_DOUBLE));
g_assert (G_VALUE_HOLDS (target_value, G_TYPE_DOUBLE));
celsius = g_value_get_double (source_value);
fahrenheit = (9 * celsius / 5) + 32.0;
if (g_test_verbose ())
g_print ("Converting %.2fC to %.2fF\n", celsius, fahrenheit);
g_value_set_double (target_value, fahrenheit);
return TRUE;
}
static gboolean
fahrenheit_to_celsius (GBinding *binding,
const GValue *source_value,
GValue *target_value,
gpointer user_data G_GNUC_UNUSED)
{
gdouble celsius, fahrenheit;
g_assert (G_VALUE_HOLDS (source_value, G_TYPE_DOUBLE));
g_assert (G_VALUE_HOLDS (target_value, G_TYPE_DOUBLE));
fahrenheit = g_value_get_double (source_value);
celsius = 5 * (fahrenheit - 32.0) / 9;
if (g_test_verbose ())
g_print ("Converting %.2fF to %.2fC\n", fahrenheit, celsius);
g_value_set_double (target_value, celsius);
return TRUE;
}
static void
binding_default (void)
{
BindingSource *source = g_object_new (binding_source_get_type (), NULL);
BindingTarget *target = g_object_new (binding_target_get_type (), NULL);
GBinding *binding;
binding = g_object_bind_property (source, "foo",
target, "bar",
G_BINDING_DEFAULT);
g_object_set (source, "foo", 42, NULL);
g_assert_cmpint (source->foo, ==, target->bar);
g_object_set (target, "bar", 47, NULL);
g_assert_cmpint (source->foo, !=, target->bar);
g_object_unref (binding);
g_object_set (source, "foo", 0, NULL);
g_assert_cmpint (source->foo, !=, target->bar);
g_object_unref (source);
g_object_unref (target);
}
static void
binding_bidirectional (void)
{
BindingSource *source = g_object_new (binding_source_get_type (), NULL);
BindingTarget *target = g_object_new (binding_target_get_type (), NULL);
GBinding *binding;
binding = g_object_bind_property (source, "foo",
target, "bar",
G_BINDING_BIDIRECTIONAL);
g_object_set (source, "foo", 42, NULL);
g_assert_cmpint (source->foo, ==, target->bar);
g_object_set (target, "bar", 47, NULL);
g_assert_cmpint (source->foo, ==, target->bar);
g_object_unref (binding);
g_object_set (source, "foo", 0, NULL);
g_assert_cmpint (source->foo, !=, target->bar);
g_object_unref (source);
g_object_unref (target);
}
static void
binding_transform (void)
{
BindingSource *source = g_object_new (binding_source_get_type (), NULL);
BindingTarget *target = g_object_new (binding_target_get_type (), NULL);
GBinding *binding;
binding = g_object_bind_property_full (source, "value",
target, "value",
G_BINDING_BIDIRECTIONAL,
celsius_to_fahrenheit,
fahrenheit_to_celsius,
NULL, NULL);
g_object_set (source, "value", 24.0, NULL);
g_assert_cmpfloat (target->value, ==, ((9 * 24.0 / 5) + 32.0));
g_object_set (target, "value", 69.0, NULL);
g_assert_cmpfloat (source->value, ==, (5 * (69.0 - 32.0) / 9));
g_object_unref (source);
g_object_unref (target);
}
int
main (int argc, char *argv[])
{
g_type_init ();
g_test_init (&argc, &argv, NULL);
g_test_add_func ("/binding/default", binding_default);
g_test_add_func ("/binding/bidirectional", binding_bidirectional);
g_test_add_func ("/binding/transform", binding_transform);
return g_test_run ();
}