/*
* 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 .
*
* Author:
* Emmanuele Bassi
*/
/**
* 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.
*
* #ClutterLayoutManager is available since Clutter 1.2
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "clutter-debug.h"
#include "clutter-layout-manager.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 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 void
clutter_layout_manager_class_init (ClutterLayoutManagerClass *klass)
{
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;
/**
* 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);
}