mutter/src/compositor/meta-background-group.c

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/* -*- mode: C; c-file-style: "gnu"; indent-tabs-mode: nil; -*- */
/**
* SECTION:meta-background-group
* @title: MetaBackgroundGroup
* @short_description: Container for background actors
*
* This class is a subclass of ClutterActor with special handling for
* MetaBackgroundActor/MetaBackgroundGroup when painting children.
* It makes sure to only draw the parts of the backgrounds not
* occluded by opaque windows.
*
* See #MetaWindowGroup for more information behind the motivation,
* and details on implementation.
*/
#include <config.h>
#include "compositor-private.h"
#include "clutter-utils.h"
#include "meta-background-actor-private.h"
#include "meta-background-group-private.h"
G_DEFINE_TYPE (MetaBackgroundGroup, meta_background_group, CLUTTER_TYPE_ACTOR);
struct _MetaBackgroundGroupPrivate
{
gpointer dummy;
};
static void
meta_background_group_dispose (GObject *object)
{
G_OBJECT_CLASS (meta_background_group_parent_class)->dispose (object);
}
static gboolean
meta_background_group_get_paint_volume (ClutterActor *actor,
ClutterPaintVolume *volume)
{
return clutter_paint_volume_set_from_allocation (volume, actor);
}
static void
meta_background_group_class_init (MetaBackgroundGroupClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
ClutterActorClass *actor_class = CLUTTER_ACTOR_CLASS (klass);
actor_class->get_paint_volume = meta_background_group_get_paint_volume;
object_class->dispose = meta_background_group_dispose;
g_type_class_add_private (klass, sizeof (MetaBackgroundGroupPrivate));
}
static void
meta_background_group_init (MetaBackgroundGroup *self)
{
self->priv = G_TYPE_INSTANCE_GET_PRIVATE (self,
META_TYPE_BACKGROUND_GROUP,
MetaBackgroundGroupPrivate);
}
/**
* meta_background_group_set_visible_region:
* @self: a #MetaBackgroundGroup
* @visible_region: (allow-none): the parts of the background to paint
*
* Sets the area of the backgrounds that is unobscured by overlapping windows.
* This is used to optimize and only paint the visible portions.
*/
void
meta_background_group_set_visible_region (MetaBackgroundGroup *self,
cairo_region_t *region)
{
GList *children, *l;
children = clutter_actor_get_children (CLUTTER_ACTOR (self));
for (l = children; l; l = l->next)
{
ClutterActor *actor = l->data;
if (META_IS_BACKGROUND_ACTOR (actor))
{
meta_background_actor_set_visible_region (META_BACKGROUND_ACTOR (actor), region);
}
else if (META_IS_BACKGROUND_GROUP (actor))
{
int x, y;
if (!meta_actor_is_untransformed (actor, &x, &y))
continue;
cairo_region_translate (region, -x, -y);
meta_background_group_set_visible_region (META_BACKGROUND_GROUP (actor), region);
cairo_region_translate (region, x, y);
}
}
g_list_free (children);
}
ClutterActor *
meta_background_group_new (void)
{
MetaBackgroundGroup *background_group;
background_group = g_object_new (META_TYPE_BACKGROUND_GROUP, NULL);
return CLUTTER_ACTOR (background_group);
}