mutter/clutter/clutter-fixed-layout.c
2009-10-14 11:31:29 +01:00

263 lines
7.1 KiB
C

/*
* 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>
*
* Based on the fixed layout code inside clutter-group.c
*/
/**
* SECTION:clutter-fixed-layout
* @short_description: A fixed layout manager
*
* #ClutterFixedLayout is a layout manager implementing the same
* layout policies as #ClutterGroup.
*
* #ClutterFixedLayout is available since Clutter 1.2
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "clutter-debug.h"
#include "clutter-fixed-layout.h"
#include "clutter-private.h"
G_DEFINE_TYPE (ClutterFixedLayout,
clutter_fixed_layout,
CLUTTER_TYPE_LAYOUT_MANAGER);
static void
clutter_fixed_layout_get_preferred_width (ClutterLayoutManager *manager,
ClutterContainer *container,
gfloat for_height,
gfloat *min_width_p,
gfloat *nat_width_p)
{
GList *children, *l;
gdouble min_left, min_right;
gdouble natural_left, natural_right;
min_left = 0;
min_right = 0;
natural_left = 0;
natural_right = 0;
children = clutter_container_get_children (container);
for (l = children; l != NULL; l = l->next)
{
ClutterActor *child = l->data;
gfloat child_x, child_min, child_natural;
child_x = clutter_actor_get_x (child);
clutter_actor_get_preferred_size (child,
&child_min, NULL,
&child_natural, NULL);
if (l == children)
{
/* First child */
min_left = child_x;
natural_left = child_x;
min_right = min_left + child_min;
natural_right = natural_left + child_natural;
}
else
{
/* Union of extents with previous children */
if (child_x < min_left)
min_left = child_x;
if (child_x < natural_left)
natural_left = child_x;
if (child_x + child_min > min_right)
min_right = child_x + child_min;
if (child_x + child_natural > natural_right)
natural_right = child_x + child_natural;
}
}
g_list_free (children);
/* The preferred size is defined as the width and height we want starting
* from our origin, since our allocation will set the origin; so we now
* need to remove any part of the request that is to the left of the origin.
*/
if (min_left < 0)
min_left = 0;
if (natural_left < 0)
natural_left = 0;
if (min_right < 0)
min_right = 0;
if (natural_right < 0)
natural_right = 0;
g_assert (min_right >= min_left);
g_assert (natural_right >= natural_left);
if (min_width_p)
*min_width_p = min_right - min_left;
if (nat_width_p)
*nat_width_p = natural_right - min_left;
}
static void
clutter_fixed_layout_get_preferred_height (ClutterLayoutManager *manager,
ClutterContainer *container,
gfloat for_width,
gfloat *min_height_p,
gfloat *nat_height_p)
{
GList *children, *l;
gdouble min_top, min_bottom;
gdouble natural_top, natural_bottom;
min_top = 0;
min_bottom = 0;
natural_top = 0;
natural_bottom = 0;
children = clutter_container_get_children (container);
for (l = children; l != NULL; l = l->next)
{
ClutterActor *child = l->data;
gfloat child_y, child_min, child_natural;
child_y = clutter_actor_get_y (child);
clutter_actor_get_preferred_size (child,
NULL, &child_min,
NULL, &child_natural);
if (l == children)
{
/* First child */
min_top = child_y;
natural_top = child_y;
min_bottom = min_top + child_min;
natural_bottom = natural_top + child_natural;
}
else
{
/* Union of extents with previous children */
if (child_y < min_top)
min_top = child_y;
if (child_y < natural_top)
natural_top = child_y;
if (child_y + child_min > min_bottom)
min_bottom = child_y + child_min;
if (child_y + child_natural > natural_bottom)
natural_bottom = child_y + child_natural;
}
}
g_list_free (children);
/* The preferred size is defined as the width and height we want starting
* from our origin, since our allocation will set the origin; so we now
* need to remove any part of the request that is above the origin.
*/
if (min_top < 0)
min_top = 0;
if (natural_top < 0)
natural_top = 0;
if (min_bottom < 0)
min_bottom = 0;
if (natural_bottom < 0)
natural_bottom = 0;
g_assert (min_bottom >= min_top);
g_assert (natural_bottom >= natural_top);
if (min_height_p)
*min_height_p = min_bottom - min_top;
if (nat_height_p)
*nat_height_p = natural_bottom - min_top;
}
static void
clutter_fixed_layout_allocate (ClutterLayoutManager *manager,
ClutterContainer *container,
const ClutterActorBox *allocation,
ClutterAllocationFlags flags)
{
GList *children, *l;
children = clutter_container_get_children (container);
for (l = children; l != NULL; l = l->next)
{
ClutterActor *child = l->data;
clutter_actor_allocate_preferred_size (child, flags);
}
g_list_free (children);
}
static void
clutter_fixed_layout_class_init (ClutterFixedLayoutClass *klass)
{
ClutterLayoutManagerClass *manager_class =
CLUTTER_LAYOUT_MANAGER_CLASS (klass);
manager_class->get_preferred_width =
clutter_fixed_layout_get_preferred_width;
manager_class->get_preferred_height =
clutter_fixed_layout_get_preferred_height;
manager_class->allocate = clutter_fixed_layout_allocate;
}
static void
clutter_fixed_layout_init (ClutterFixedLayout *self)
{
}
/**
* clutter_fixed_layout_new:
*
* Creates a new #ClutterFixedLayout
*
* Return value: the newly created #ClutterFixedLayout
*
* Since: 1.2
*/
ClutterLayoutManager *
clutter_fixed_layout_new (void)
{
return g_object_new (CLUTTER_TYPE_FIXED_LAYOUT, NULL);
}