mutter/clutter/clutter-layout-manager.c

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/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Copyright (C) 2009 Intel Corporation.
*
* 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, see <http://www.gnu.org/licenses/>.
*
* Author:
* Emmanuele Bassi <ebassi@linux.intel.com>
*/
/**
* SECTION:clutter-layout-manager
* @short_description: Layout managers base class
*
* #ClutterLayoutManager is a base abstract class for layout managers. A
* layout manager implements the layouting policy for a composite or a
* container actor: it controls the preferred size of the actor to which
* it has been paired, and it controls the allocation of its children.
*
* Any composite or container #ClutterActor subclass can delegate the
* layouting of its children to a #ClutterLayoutManager. Clutter provides
* a generic container using #ClutterLayoutManager called #ClutterBox.
*
* Clutter provides some simple #ClutterLayoutManager sub-classes, like
* #ClutterFixedLayout and #ClutterBinLayout.
*
* <refsect2 id="ClutterLayoutManager-use-in-Actor">
* <title>Using ClutterLayoutManager inside an Actor</title>
* <para>In order to use a #ClutterLayoutManager inside a #ClutterActor
* sub-class you should invoke clutter_layout_manager_get_preferred_width()
* inside the <structname>ClutterActor</structname>::get_preferred_width()
* virtual function and clutter_layout_manager_get_preferred_height()
* inside the <structname>ClutterActor</structname>::get_preferred_height()
* virtual function implementations. You should also call
* clutter_layout_manager_allocate() inside the implementation of the
* <structname>ClutterActor</structname>::allocate() virtual
* function.</para>
* <para>In order to receive notifications for changes in the layout
* manager policies you should also connect to the
* #ClutterLayoutManager::layout-changed signal and queue a relayout
* on your actor. The following code should be enough if the actor
* does not need to perform specific operations whenever a layout
* manager changes:</para>
* <informalexample><programlisting>
* g_signal_connect_swapped (layout_manager,
* "layout-changed",
* G_CALLBACK (clutter_actor_queue_relayout),
* actor);
* </programlisting></informalexample>
* </refsect2>
*
* <refsect2 id="ClutterLayoutManager-implementation">
* <title>Implementing a ClutterLayoutManager</title>
* <para>The implementation of a layout manager does not differ from
* the implementation of the size requisition and allocation bits of
* #ClutterActor, so you should read the relative documentation
2009-10-19 06:44:29 -04:00
* <link linkend="clutter-subclassing-ClutterActor">for subclassing
* ClutterActor</link>.</para>
* <para>The layout manager implementation can hold a back reference
* to the #ClutterContainer by implementing the set_container()
* virtual function. The layout manager should not hold a reference
* on the container actor, to avoid reference cycles.</para>
* <para>If the layout manager has properties affecting the layout
* policies then it should emit the #ClutterLayoutManager::layout-changed
* signal on itself by using the clutter_layout_manager_layout_changed()
* function.</para>
* </refsect2>
*
* #ClutterLayoutManager is available since Clutter 1.2
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include <glib-object.h>
#include <gobject/gvaluecollector.h>
#include "clutter-debug.h"
#include "clutter-layout-manager.h"
#include "clutter-layout-meta.h"
#include "clutter-marshal.h"
#include "clutter-private.h"
#define LAYOUT_MANAGER_WARN_NOT_IMPLEMENTED(m,method) G_STMT_START { \
GObject *_obj = G_OBJECT (m); \
g_warning ("Layout managers of type %s do not implement " \
"the ClutterLayoutManager::%s method", \
G_OBJECT_TYPE_NAME (_obj), \
(method)); } G_STMT_END
enum
{
LAYOUT_CHANGED,
LAST_SIGNAL
};
G_DEFINE_ABSTRACT_TYPE (ClutterLayoutManager,
clutter_layout_manager,
G_TYPE_INITIALLY_UNOWNED);
static GQuark quark_layout_meta = 0;
static guint manager_signals[LAST_SIGNAL] = { 0, };
static void
layout_manager_real_get_preferred_width (ClutterLayoutManager *manager,
ClutterContainer *container,
gfloat for_height,
gfloat *min_width_p,
gfloat *nat_width_p)
{
LAYOUT_MANAGER_WARN_NOT_IMPLEMENTED (manager, "get_preferred_width");
if (min_width_p)
*min_width_p = 0.0;
if (nat_width_p)
*nat_width_p = 0.0;
}
static void
layout_manager_real_get_preferred_height (ClutterLayoutManager *manager,
ClutterContainer *container,
gfloat for_width,
gfloat *min_height_p,
gfloat *nat_height_p)
{
LAYOUT_MANAGER_WARN_NOT_IMPLEMENTED (manager, "get_preferred_height");
if (min_height_p)
*min_height_p = 0.0;
if (nat_height_p)
*nat_height_p = 0.0;
}
static void
layout_manager_real_allocate (ClutterLayoutManager *manager,
ClutterContainer *container,
const ClutterActorBox *allocation,
ClutterAllocationFlags flags)
{
LAYOUT_MANAGER_WARN_NOT_IMPLEMENTED (manager, "allocate");
}
static ClutterLayoutMeta *
layout_manager_real_create_child_meta (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor)
{
return NULL;
}
static void
clutter_layout_manager_class_init (ClutterLayoutManagerClass *klass)
{
quark_layout_meta =
g_quark_from_static_string ("clutter-layout-manager-child-meta");
klass->get_preferred_width = layout_manager_real_get_preferred_width;
klass->get_preferred_height = layout_manager_real_get_preferred_height;
klass->allocate = layout_manager_real_allocate;
klass->create_child_meta = layout_manager_real_create_child_meta;
/**
* ClutterLayoutManager::layout-changed:
* @manager: the #ClutterLayoutManager that emitted the signal
*
* The ::layout-changed signal is emitted each time a layout manager
* has been changed. Every #ClutterActor using the @manager instance
* as a layout manager should connect a handler to the ::layout-changed
* signal and queue a relayout on themselves:
*
* |[
* static void layout_changed (ClutterLayoutManager *manager,
* ClutterActor *self)
* {
* clutter_actor_queue_relayout (self);
* }
* ...
* self->manager = g_object_ref_sink (manager);
* g_signal_connect (self->manager, "layout-changed",
* G_CALLBACK (layout_changed),
* self);
* ]|
*
* Sub-classes of #ClutterLayoutManager that implement a layout that
* can be controlled or changed using parameters should emit the
* ::layout-changed signal whenever one of the parameters changes,
* by using clutter_layout_manager_layout_changed().
*
* Since: 1.2
*/
manager_signals[LAYOUT_CHANGED] =
g_signal_new (I_("layout-changed"),
G_TYPE_FROM_CLASS (klass),
G_SIGNAL_RUN_LAST,
G_STRUCT_OFFSET (ClutterLayoutManagerClass,
layout_changed),
NULL, NULL,
clutter_marshal_VOID__VOID,
G_TYPE_NONE, 0);
}
static void
clutter_layout_manager_init (ClutterLayoutManager *manager)
{
}
/**
* clutter_layout_manager_get_preferred_width:
* @manager: a #ClutterLayoutManager
* @container: the #ClutterContainer using @manager
* @for_height: the height for which the width should be computed, or -1
* @min_width_p: (out) (allow-none): return location for the minimum width
* of the layout, or %NULL
* @nat_width_p: (out) (allow-none): return location for the natural width
* of the layout, or %NULL
*
* Computes the minimum and natural widths of the @container according
* to @manager.
*
* See also clutter_actor_get_preferred_width()
*
* Since: 1.2
*/
void
clutter_layout_manager_get_preferred_width (ClutterLayoutManager *manager,
ClutterContainer *container,
gfloat for_height,
gfloat *min_width_p,
gfloat *nat_width_p)
{
ClutterLayoutManagerClass *klass;
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
g_return_if_fail (CLUTTER_IS_CONTAINER (container));
klass = CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager);
klass->get_preferred_width (manager, container, for_height,
min_width_p,
nat_width_p);
}
/**
* clutter_layout_manager_get_preferred_height:
* @manager: a #ClutterLayoutManager
* @container: the #ClutterContainer using @manager
* @for_width: the width for which the height should be computed, or -1
* @min_height_p: (out) (allow-none): return location for the minimum height
* of the layout, or %NULL
* @nat_height_p: (out) (allow-none): return location for the natural height
* of the layout, or %NULL
*
* Computes the minimum and natural heights of the @container according
* to @manager.
*
* See also clutter_actor_get_preferred_height()
*
* Since: 1.2
*/
void
clutter_layout_manager_get_preferred_height (ClutterLayoutManager *manager,
ClutterContainer *container,
gfloat for_width,
gfloat *min_height_p,
gfloat *nat_height_p)
{
ClutterLayoutManagerClass *klass;
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
g_return_if_fail (CLUTTER_IS_CONTAINER (container));
klass = CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager);
klass->get_preferred_height (manager, container, for_width,
min_height_p,
nat_height_p);
}
/**
* clutter_layout_manager_allocate:
* @manager: a #ClutterLayoutManager
* @container: the #ClutterContainer using @manager
* @allocation: the #ClutterActorBox containing the allocated area
* of @container
* @flags: the allocation flags
*
* Allocates the children of @container given an area
*
* See also clutter_actor_allocate()
*
* Since: 1.2
*/
void
clutter_layout_manager_allocate (ClutterLayoutManager *manager,
ClutterContainer *container,
const ClutterActorBox *allocation,
ClutterAllocationFlags flags)
{
ClutterLayoutManagerClass *klass;
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
g_return_if_fail (CLUTTER_IS_CONTAINER (container));
g_return_if_fail (allocation != NULL);
klass = CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager);
klass->allocate (manager, container, allocation, flags);
}
/**
* clutter_layout_manager_layout_changed:
* @manager: a #ClutterLayoutManager
*
* Emits the #ClutterLayoutManager::layout-changed signal on @manager
*
* This function should only be called by implementations of the
* #ClutterLayoutManager class
*
* Since: 1.2
*/
void
clutter_layout_manager_layout_changed (ClutterLayoutManager *manager)
{
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
g_signal_emit (manager, manager_signals[LAYOUT_CHANGED], 0);
}
/**
* clutter_layout_manager_set_container:
* @manager: a #ClutterLayoutManager
* @container: (allow-none): a #ClutterContainer using @manager
*
* If the #ClutterLayoutManager sub-class allows it, allow
* adding a weak reference of the @container using @manager
* from within the layout manager
*
* The layout manager should not increase the reference
* count of the @container
*
* Since: 1.2
*/
void
clutter_layout_manager_set_container (ClutterLayoutManager *manager,
ClutterContainer *container)
{
ClutterLayoutManagerClass *klass;
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
g_return_if_fail (container == NULL || CLUTTER_IS_CONTAINER (container));
klass = CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager);
if (klass->set_container)
klass->set_container (manager, container);
}
static inline ClutterLayoutMeta *
create_child_meta (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor)
{
ClutterLayoutManagerClass *klass;
klass = CLUTTER_LAYOUT_MANAGER_GET_CLASS (manager);
return klass->create_child_meta (manager, container, actor);
}
static gboolean
has_child_meta (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor)
{
ClutterLayoutMeta *layout_meta = NULL;
layout_meta = g_object_get_qdata (G_OBJECT (actor), quark_layout_meta);
if (layout_meta != NULL)
{
ClutterChildMeta *child_meta = CLUTTER_CHILD_META (layout_meta);
if (layout_meta->manager == manager &&
child_meta->container == container &&
child_meta->actor == actor)
return TRUE;
}
return FALSE;
}
static inline ClutterLayoutMeta *
get_child_meta (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor)
{
ClutterLayoutMeta *layout = NULL;
layout = g_object_get_qdata (G_OBJECT (actor), quark_layout_meta);
if (layout != NULL)
{
ClutterChildMeta *child = CLUTTER_CHILD_META (layout);
if (layout->manager == manager &&
child->container == container &&
child->actor == actor)
return layout;
/* if the LayoutMeta referenced is not attached to the
* layout manager then we simply ask the layout manager
* to replace it with the right one
*/
layout = create_child_meta (manager, container, actor);
if (layout != NULL)
{
g_assert (CLUTTER_IS_LAYOUT_META (layout));
g_object_set_qdata_full (G_OBJECT (actor), quark_layout_meta,
layout,
(GDestroyNotify) g_object_unref);
}
return layout;
}
return NULL;
}
/**
* clutter_layout_manager_get_child_meta:
* @manager: a #ClutterLayoutManager
* @container: a #ClutterContainer using @manager
* @actor: a #ClutterActor child of @container
*
* Retrieves the #ClutterLayoutMeta that the layout @manager associated
* to the @actor child of @container
*
* Return value: a #ClutterLayoutMeta or %NULL
*
* Since: 1.0
*/
ClutterLayoutMeta *
clutter_layout_manager_get_child_meta (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor)
{
g_return_val_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager), NULL);
g_return_val_if_fail (CLUTTER_IS_CONTAINER (container), NULL);
g_return_val_if_fail (CLUTTER_IS_ACTOR (actor), NULL);
return get_child_meta (manager, container, actor);
}
/**
* clutter_layout_manager_add_child_meta:
* @manager: a #ClutterLayoutManager
* @container: a #ClutterContainer using @manager
* @actor: a #ClutterActor child of @container
*
* Creates and binds a #ClutterLayoutMeta for @manager to
* a child of @container
*
* This function should only be used when implementing containers
* using #ClutterLayoutManager and not by application code
*
* Typically, containers should bind a #ClutterLayoutMeta created
* by a #ClutterLayoutManager when adding a new child, e.g.:
*
* |[
* static void
* my_container_add (ClutterContainer *container,
* ClutterActor *actor)
* {
* MyContainer *self = MY_CONTAINER (container);
*
* self->children = g_slist_append (self->children, actor);
* clutter_actor_set_parent (actor, CLUTTER_ACTOR (self));
*
* clutter_layout_manager_add_child_meta (self->layout,
* container,
* actor);
*
* clutter_actor_queue_relayout (CLUTTER_ACTOR (self));
*
* g_signal_emit_by_name (container, "actor-added");
* }
* ]|
*
* The #ClutterLayoutMeta should be removed when removing an
* actor; see clutter_layout_manager_remove_child_meta()
*
* Since: 1.2
*/
void
clutter_layout_manager_add_child_meta (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor)
{
ClutterLayoutMeta *meta;
meta = create_child_meta (manager, container, actor);
if (meta == NULL)
return;
g_object_set_qdata_full (G_OBJECT (actor), quark_layout_meta,
meta,
(GDestroyNotify) g_object_unref);
}
/**
* clutter_layout_manager_remove_child_meta:
* @manager: a #ClutterLayoutManager
* @container: a #ClutterContainer using @manager
* @actor: a #ClutterActor child of @container
*
* Unbinds and unrefs a #ClutterLayoutMeta for @manager from
* a child of @container
*
* This function should only be used when implementing containers
* using #ClutterLayoutManager and not by application code
*
* Typically, containers should remove a #ClutterLayoutMeta created
* by a #ClutterLayoutManager when removing a child, e.g.:
*
* |[
* static void
* my_container_remove (ClutterContainer *container,
* ClutterActor *actor)
* {
* MyContainer *self = MY_CONTAINER (container);
*
* g_object_ref (actor);
*
* self->children = g_slist_remove (self->children, actor);
* clutter_actor_unparent (actor);
*
* clutter_layout_manager_remove_child_meta (self->layout,
* container,
* actor);
*
* clutter_actor_queue_relayout (CLUTTER_ACTOR (self));
*
* g_signal_emit_by_name (container, "actor-removed");
*
* g_object_unref (actor);
* }
* ]|
*
* See also clutter_layout_manager_add_child_meta()
*
* Since: 1.2
*/
void
clutter_layout_manager_remove_child_meta (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor)
{
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
g_return_if_fail (CLUTTER_IS_CONTAINER (container));
g_return_if_fail (CLUTTER_IS_ACTOR (actor));
if (has_child_meta (manager, container, actor))
g_object_set_qdata (G_OBJECT (actor), quark_layout_meta, NULL);
}
static inline gboolean
layout_set_property_internal (ClutterLayoutManager *manager,
GObject *gobject,
GParamSpec *pspec,
const GValue *value)
{
if (pspec->flags & G_PARAM_CONSTRUCT_ONLY)
{
g_warning ("%s: Child property '%s' of the layout manager of "
"type '%s' is constructor-only",
G_STRLOC, pspec->name, G_OBJECT_TYPE_NAME (manager));
return FALSE;
}
if (!(pspec->flags & G_PARAM_WRITABLE))
{
g_warning ("%s: Child property '%s' of the layout manager of "
"type '%s' is not writable",
G_STRLOC, pspec->name, G_OBJECT_TYPE_NAME (manager));
return FALSE;
}
g_object_set_property (gobject, pspec->name, value);
return TRUE;
}
static inline gboolean
layout_get_property_internal (ClutterLayoutManager *manager,
GObject *gobject,
GParamSpec *pspec,
GValue *value)
{
if (!(pspec->flags & G_PARAM_READABLE))
{
g_warning ("%s: Child property '%s' of the layout manager of "
"type '%s' is not readable",
G_STRLOC, pspec->name, G_OBJECT_TYPE_NAME (manager));
return FALSE;
}
g_object_get_property (gobject, pspec->name, value);
return TRUE;
}
/**
* clutter_layout_manager_child_set:
* @manager: a #ClutterLayoutManager
* @container: a #ClutterContainer using @manager
* @actor: a #ClutterActor child of @container
* @first_property: the first property name
* @Varargs: a list of property name and value pairs
*
* Sets a list of properties and their values on the #ClutterLayoutMeta
* associated by @manager to a child of @container
*
* Languages bindings should use clutter_layout_manager_child_set_property()
* instead
*
* Since: 1.2
*/
void
clutter_layout_manager_child_set (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor,
const gchar *first_property,
...)
{
ClutterLayoutMeta *meta;
GObjectClass *klass;
const gchar *pname;
va_list var_args;
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
g_return_if_fail (CLUTTER_IS_CONTAINER (container));
g_return_if_fail (CLUTTER_IS_ACTOR (actor));
g_return_if_fail (first_property != NULL);
meta = get_child_meta (manager, container, actor);
if (meta == NULL)
{
g_warning ("Layout managers of type '%s' do not support "
"child metadata",
g_type_name (G_OBJECT_TYPE (manager)));
return;
}
klass = G_OBJECT_GET_CLASS (meta);
va_start (var_args, first_property);
pname = first_property;
while (pname)
{
GValue value = { 0, };
GParamSpec *pspec;
gchar *error;
gboolean res;
pspec = g_object_class_find_property (klass, pname);
if (pspec == NULL)
{
g_warning ("%s: Layout managers of type '%s' have no child "
"property named '%s'",
G_STRLOC, G_OBJECT_TYPE_NAME (manager), pname);
break;
}
g_value_init (&value, G_PARAM_SPEC_VALUE_TYPE (pspec));
G_VALUE_COLLECT (&value, var_args, 0, &error);
if (error)
{
g_warning ("%s: %s", G_STRLOC, error);
g_free (error);
break;
}
res = layout_set_property_internal (manager, G_OBJECT (meta),
pspec,
&value);
g_value_unset (&value);
if (!res)
break;
pname = va_arg (var_args, gchar*);
}
va_end (var_args);
}
/**
* clutter_layout_manager_child_set_property:
* @manager: a #ClutterLayoutManager
* @container: a #ClutterContainer using @manager
* @actor: a #ClutterActor child of @container
* @property_name: the name of the property to set
* @value: a #GValue with the value of the property to set
*
* Sets a property on the #ClutterLayoutMeta created by @manager and
* attached to a child of @container
*
* Since: 1.2
*/
void
clutter_layout_manager_child_set_property (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor,
const gchar *property_name,
const GValue *value)
{
ClutterLayoutMeta *meta;
GObjectClass *klass;
GParamSpec *pspec;
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
g_return_if_fail (CLUTTER_IS_CONTAINER (container));
g_return_if_fail (CLUTTER_IS_ACTOR (actor));
g_return_if_fail (property_name != NULL);
g_return_if_fail (value != NULL);
meta = get_child_meta (manager, container, actor);
if (meta == NULL)
{
g_warning ("Layout managers of type '%s' do not support "
"child metadata",
g_type_name (G_OBJECT_TYPE (manager)));
return;
}
klass = G_OBJECT_GET_CLASS (meta);
pspec = g_object_class_find_property (klass, property_name);
if (pspec == NULL)
{
g_warning ("%s: Layout managers of type '%s' have no child "
"property named '%s'",
G_STRLOC, G_OBJECT_TYPE_NAME (manager), property_name);
return;
}
layout_set_property_internal (manager, G_OBJECT (meta), pspec, value);
}
/**
* clutter_layout_manager_child_get:
* @manager: a #ClutterLayoutManager
* @container: a #ClutterContainer using @manager
* @actor: a #ClutterActor child of @container
* @first_property: the name of the first property
* @Varargs: a list of property name and return location for the value pairs
*
* Retrieves the values for a list of properties out of the
* #ClutterLayoutMeta created by @manager and attached to the
* child of a @container
*
* Since: 1.2
*/
void
clutter_layout_manager_child_get (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor,
const gchar *first_property,
...)
{
ClutterLayoutMeta *meta;
GObjectClass *klass;
const gchar *pname;
va_list var_args;
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
g_return_if_fail (CLUTTER_IS_CONTAINER (container));
g_return_if_fail (CLUTTER_IS_ACTOR (actor));
g_return_if_fail (first_property != NULL);
meta = get_child_meta (manager, container, actor);
if (meta == NULL)
{
g_warning ("Layout managers of type '%s' do not support "
"child metadata",
g_type_name (G_OBJECT_TYPE (manager)));
return;
}
klass = G_OBJECT_GET_CLASS (meta);
va_start (var_args, first_property);
pname = first_property;
while (pname)
{
GValue value = { 0, };
GParamSpec *pspec;
gchar *error;
gboolean res;
pspec = g_object_class_find_property (klass, pname);
if (pspec == NULL)
{
g_warning ("%s: Layout managers of type '%s' have no child "
"property named '%s'",
G_STRLOC, G_OBJECT_TYPE_NAME (manager), pname);
break;
}
g_value_init (&value, G_PARAM_SPEC_VALUE_TYPE (pspec));
res = layout_get_property_internal (manager, G_OBJECT (meta),
pspec,
&value);
if (!res)
{
g_value_unset (&value);
break;
}
G_VALUE_LCOPY (&value, var_args, 0, &error);
if (error)
{
g_warning ("%s: %s", G_STRLOC, error);
g_free (error);
g_value_unset (&value);
break;
}
g_value_unset (&value);
pname = va_arg (var_args, gchar*);
}
va_end (var_args);
}
/**
* clutter_layout_manager_child_get_property:
* @manager: a #ClutterLayoutManager
* @container: a #ClutterContainer using @manager
* @actor: a #ClutterActor child of @container
* @property_name: the name of the property to get
* @value: a #GValue with the value of the property to get
*
* Gets a property on the #ClutterLayoutMeta created by @manager and
* attached to a child of @container
*
* The #GValue must already be initialized to the type of the property
* and has to be unset with g_value_unset() after extracting the real
* value out of it
*
* Since: 1.2
*/
void
clutter_layout_manager_child_get_property (ClutterLayoutManager *manager,
ClutterContainer *container,
ClutterActor *actor,
const gchar *property_name,
GValue *value)
{
ClutterLayoutMeta *meta;
GObjectClass *klass;
GParamSpec *pspec;
g_return_if_fail (CLUTTER_IS_LAYOUT_MANAGER (manager));
g_return_if_fail (CLUTTER_IS_CONTAINER (container));
g_return_if_fail (CLUTTER_IS_ACTOR (actor));
g_return_if_fail (property_name != NULL);
g_return_if_fail (value != NULL);
meta = get_child_meta (manager, container, actor);
if (meta == NULL)
{
g_warning ("Layout managers of type %s do not support "
"child metadata",
g_type_name (G_OBJECT_TYPE (manager)));
return;
}
klass = G_OBJECT_GET_CLASS (meta);
pspec = g_object_class_find_property (klass, property_name);
if (pspec == NULL)
{
g_warning ("%s: Layout managers of type '%s' have no child "
"property named '%s'",
G_STRLOC, G_OBJECT_TYPE_NAME (manager), property_name);
return;
}
layout_get_property_internal (manager, G_OBJECT (meta), pspec, value);
}