mutter/clutter/clutter-clone.c

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/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Copyright (C) 2008 Intel Corporation.
*
* Authored By: Robert Bragg <robert@linux.intel.com>
*
* 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/>.
*/
/**
* SECTION:clutterclone
* @short_description: An actor that displays a clone of a source actor
*
* #ClutterClone is a #ClutterActor which draws with the paint
* function of another actor, scaled to fit its own allocation.
*
* #ClutterClone can be used to efficiently clone any other actor.
*
* <note><para>This is different from clutter_texture_new_from_actor()
* which requires support for FBOs in the underlying GL
* implementation.</para></note>
*
* #ClutterClone is available since Clutter 1.0
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "clutter-color.h"
#include "clutter-clone.h"
#include "clutter-debug.h"
#include "clutter-main.h"
#include "clutter-private.h"
#include "cogl/cogl.h"
G_DEFINE_TYPE (ClutterClone, clutter_clone, CLUTTER_TYPE_ACTOR);
enum
{
PROP_0,
PROP_SOURCE
};
#define CLUTTER_CLONE_GET_PRIVATE(obj) (G_TYPE_INSTANCE_GET_PRIVATE ((obj), CLUTTER_TYPE_CLONE, ClutterClonePrivate))
struct _ClutterClonePrivate
{
ClutterActor *clone_source;
};
static void
clutter_clone_get_preferred_width (ClutterActor *self,
ClutterUnit for_height,
ClutterUnit *min_width_p,
ClutterUnit *natural_width_p)
{
ClutterClonePrivate *priv = CLUTTER_CLONE (self)->priv;
ClutterActor *clone_source = priv->clone_source;
if (G_UNLIKELY (clone_source == NULL))
{
if (min_width_p)
*min_width_p = 0;
if (natural_width_p)
*natural_width_p = 0;
}
else
clutter_actor_get_preferred_width (clone_source,
for_height,
min_width_p,
natural_width_p);
}
static void
clutter_clone_get_preferred_height (ClutterActor *self,
ClutterUnit for_width,
ClutterUnit *min_height_p,
ClutterUnit *natural_height_p)
{
ClutterClonePrivate *priv = CLUTTER_CLONE (self)->priv;
ClutterActor *clone_source = priv->clone_source;
if (G_UNLIKELY (clone_source == NULL))
{
if (min_height_p)
*min_height_p = 0;
if (natural_height_p)
*natural_height_p = 0;
}
else
clutter_actor_get_preferred_height (clone_source,
for_width,
min_height_p,
natural_height_p);
}
static void
clutter_clone_paint (ClutterActor *self)
{
ClutterClone *clone = CLUTTER_CLONE (self);
ClutterClonePrivate *priv = clone->priv;
ClutterActor *parent;
ClutterGeometry geom, clone_geom;
gfloat x_scale, y_scale;
if (G_UNLIKELY (priv->clone_source == NULL))
return;
CLUTTER_NOTE (PAINT,
"painting clone actor '%s'",
clutter_actor_get_name (self) ? clutter_actor_get_name (self)
: "unknown");
/* get our allocated size */
clutter_actor_get_allocation_geometry (self, &geom);
/* and get the allocated size of the source */
clutter_actor_get_allocation_geometry (priv->clone_source, &clone_geom);
/* We need to scale what the clone-source actor paints to fill our own
* allocation...
*/
x_scale = (gfloat) geom.width / clone_geom.width;
y_scale = (gfloat) geom.height / clone_geom.height;
cogl_scale (x_scale, y_scale, 1.0);
/* The final bits of magic:
* - We need to make sure that when the clone-source actor's paint method
* calls clutter_actor_get_paint_opacity, it traverses our parent not it's
* real parent.
* - We need to stop clutter_actor_paint applying the model view matrix of
* the clone source actor.
*/
parent = clutter_actor_get_parent (self);
_clutter_actor_set_opacity_parent (priv->clone_source, parent);
_clutter_actor_set_enable_model_view_transform (priv->clone_source, FALSE);
clutter_actor_paint (priv->clone_source);
_clutter_actor_set_enable_model_view_transform (priv->clone_source, TRUE);
_clutter_actor_set_opacity_parent (priv->clone_source, NULL);
}
static void
clutter_clone_allocate (ClutterActor *self,
const ClutterActorBox *box,
gboolean origin_changed)
{
ClutterClonePrivate *priv = CLUTTER_CLONE (self)->priv;
ClutterActorClass *parent_class;
/* chain up */
parent_class = CLUTTER_ACTOR_CLASS (clutter_clone_parent_class);
parent_class->allocate (self, box, origin_changed);
if (G_UNLIKELY (priv->clone_source == NULL))
return;
/* we act like a "foster parent" for the source we are cloning;
* if the source has not been parented we have to force an
* allocation on it, so that we can paint it correctly from
* within out paint() implementation. since the actor does not
* have a parent, and thus it won't be painted by the usual
* paint cycle, we can safely give it as much size as it requires
*/
if (clutter_actor_get_parent (priv->clone_source) == NULL)
{
clutter_actor_allocate_preferred_size (priv->clone_source,
origin_changed);
}
}
static void
clutter_clone_set_property (GObject *gobject,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
ClutterClone *clone = CLUTTER_CLONE (gobject);
switch (prop_id)
{
case PROP_SOURCE:
clutter_clone_set_source (clone, g_value_get_object (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
clutter_clone_get_property (GObject *gobject,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
ClutterClonePrivate *priv = CLUTTER_CLONE (gobject)->priv;
switch (prop_id)
{
case PROP_SOURCE:
g_value_set_object (value, priv->clone_source);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
clutter_clone_dispose (GObject *gobject)
{
ClutterClonePrivate *priv = CLUTTER_CLONE (gobject)->priv;
if (priv->clone_source)
{
g_object_unref (priv->clone_source);
priv->clone_source = NULL;
}
G_OBJECT_CLASS (clutter_clone_parent_class)->dispose (gobject);
}
static void
clutter_clone_class_init (ClutterCloneClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
ClutterActorClass *actor_class = CLUTTER_ACTOR_CLASS (klass);
GParamSpec *pspec = NULL;
g_type_class_add_private (gobject_class, sizeof (ClutterClonePrivate));
actor_class->paint = clutter_clone_paint;
actor_class->get_preferred_width = clutter_clone_get_preferred_width;
actor_class->get_preferred_height = clutter_clone_get_preferred_height;
actor_class->allocate = clutter_clone_allocate;
gobject_class->dispose = clutter_clone_dispose;
gobject_class->set_property = clutter_clone_set_property;
gobject_class->get_property = clutter_clone_get_property;
/**
* ClutterClone:source:
*
* This property specifies the source actor being cloned.
*
* Since: 1.0
*/
pspec = g_param_spec_object ("source",
"Source",
"Specifies the actor to be cloned",
CLUTTER_TYPE_ACTOR,
G_PARAM_CONSTRUCT_ONLY |
CLUTTER_PARAM_READWRITE);
g_object_class_install_property (gobject_class, PROP_SOURCE, pspec);
}
static void
clutter_clone_init (ClutterClone *self)
{
ClutterClonePrivate *priv;
self->priv = priv = CLUTTER_CLONE_GET_PRIVATE (self);
priv->clone_source = NULL;
}
/**
* clutter_clone_new:
* @source: a #ClutterActor, or %NULL
*
* Creates a new #ClutterActor which clones @source/
*
* Return value: the newly created #ClutterClone
*
* Since: 1.0
*/
ClutterActor *
clutter_clone_new (ClutterActor *source)
{
return g_object_new (CLUTTER_TYPE_CLONE, "source", source, NULL);
}
/**
* clutter_clone_set_source:
* @clone: a #ClutterClone
* @source: a #ClutterActor, or %NULL
*
* Sets @source as the source actor to be cloned by @clone.
*
* Since: 1.0
*/
void
clutter_clone_set_source (ClutterClone *clone,
ClutterActor *source)
{
ClutterClonePrivate *priv;
g_return_if_fail (CLUTTER_IS_CLONE (clone));
g_return_if_fail (source == NULL || CLUTTER_IS_ACTOR (source));
priv = clone->priv;
if (priv->clone_source)
{
g_object_unref (priv->clone_source);
priv->clone_source = NULL;
}
if (source)
priv->clone_source = g_object_ref (source);
g_object_notify (G_OBJECT (clone), "source");
clutter_actor_queue_relayout (CLUTTER_ACTOR (clone));
}
/**
* clutter_clone_get_source:
* @clone: a #ClutterClone
*
* Retrieves the source #ClutterActor being cloned by @clone
*
* Return value: the actor source for the clone
*
* Since: 1.0
*/
ClutterActor *
clutter_clone_get_source (ClutterClone *clone)
{
g_return_val_if_fail (CLUTTER_IS_CLONE (clone), NULL);
return clone->priv->clone_source;
}