mutter/clutter/clutter-bind-constraint.c

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/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Copyright (C) 2010 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>
*/
/**
2010-05-19 11:10:05 -04:00
* SECTION:clutter-bind-constraint
* @Title: ClutterBindConstraint
* @Short_Description: A constraint binding the position of an actor
*
* #ClutterBindConstraint is a #ClutterConstraint that binds the position of
* the #ClutterActor to which it is applied to the the position of another
* #ClutterActor.
*
* #ClutterBindConstraint is available since Clutter 1.4
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "clutter-bind-constraint.h"
#include "clutter-constraint.h"
#include "clutter-debug.h"
#include "clutter-enum-types.h"
#include "clutter-private.h"
#define CLUTTER_BIND_CONSTRAINT_CLASS(klass) (G_TYPE_CHECK_CLASS_CAST ((klass), CLUTTER_TYPE_BIND_CONSTRAINT, ClutterBindConstraintClass))
#define CLUTTER_IS_BIND_CONSTRAINT_CLASS(klass) (G_TYPE_CHECK_CLASS_TYPE ((klass), CLUTTER_TYPE_BIND_CONSTRAINT))
#define CLUTTER_BIND_CONSTRAINT_GET_CLASS(obj) (G_TYPE_INSTANCE_GET_CLASS ((obj), CLUTTER_TYPE_BIND_CONSTRAINT, ClutterBindConstraintClass))
typedef struct _ClutterBindConstraintClass ClutterBindConstraintClass;
struct _ClutterBindConstraint
{
ClutterConstraint parent_instance;
ClutterActor *source;
ClutterBindCoordinate coordinate;
gfloat offset;
};
struct _ClutterBindConstraintClass
{
ClutterConstraintClass parent_class;
};
enum
{
PROP_0,
PROP_SOURCE,
PROP_COORDINATE,
PROP_OFFSET
};
G_DEFINE_TYPE (ClutterBindConstraint,
clutter_bind_constraint,
CLUTTER_TYPE_CONSTRAINT);
static void
update_actor_position (ClutterBindConstraint *bind)
{
ClutterVertex source_position;
ClutterActor *actor;
if (!clutter_actor_meta_get_enabled (CLUTTER_ACTOR_META (bind)))
return;
actor = clutter_actor_meta_get_actor (CLUTTER_ACTOR_META (bind));
if (actor == NULL)
return;
source_position.x = clutter_actor_get_x (bind->source);
source_position.y = clutter_actor_get_y (bind->source);
source_position.z = clutter_actor_get_depth (bind->source);
switch (bind->coordinate)
{
case CLUTTER_BIND_X:
clutter_actor_set_x (actor, source_position.x + bind->offset);
break;
case CLUTTER_BIND_Y:
clutter_actor_set_y (actor, source_position.y + bind->offset);
break;
case CLUTTER_BIND_Z:
clutter_actor_set_depth (actor, source_position.z + bind->offset);
break;
}
}
static void
source_position_changed (GObject *gobject,
GParamSpec *pspec,
ClutterBindConstraint *bind)
{
if (strcmp (pspec->name, "x") == 0 ||
strcmp (pspec->name, "y") == 0 ||
strcmp (pspec->name, "depth") == 0)
{
update_actor_position (bind);
}
}
static void
source_destroyed (ClutterActor *actor,
ClutterBindConstraint *bind)
{
bind->source = NULL;
}
static void
_clutter_bind_constraint_set_source (ClutterBindConstraint *bind,
ClutterActor *source)
{
ClutterActor *old_source = bind->source;
if (old_source != NULL)
{
g_signal_handlers_disconnect_by_func (old_source,
G_CALLBACK (source_destroyed),
bind);
g_signal_handlers_disconnect_by_func (old_source,
G_CALLBACK (source_position_changed),
bind);
}
bind->source = source;
g_signal_connect (bind->source, "notify",
G_CALLBACK (source_position_changed),
bind);
g_signal_connect (bind->source, "destroy",
G_CALLBACK (source_destroyed),
bind);
update_actor_position (bind);
g_object_notify (G_OBJECT (bind), "source");
}
static void
_clutter_bind_constraint_set_coordinate (ClutterBindConstraint *bind,
ClutterBindCoordinate coord)
{
if (bind->coordinate == coord)
return;
bind->coordinate = coord;
update_actor_position (bind);
g_object_notify (G_OBJECT (bind), "coordinate");
}
static void
_clutter_bind_constraint_set_offset (ClutterBindConstraint *bind,
gfloat offset)
{
if (fabs (bind->offset - offset) < 0.00001f)
return;
bind->offset = offset;
update_actor_position (bind);
g_object_notify (G_OBJECT (bind), "offset");
}
static void
clutter_bind_constraint_set_property (GObject *gobject,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
ClutterBindConstraint *bind = CLUTTER_BIND_CONSTRAINT (gobject);
switch (prop_id)
{
case PROP_SOURCE:
_clutter_bind_constraint_set_source (bind, g_value_get_object (value));
break;
case PROP_COORDINATE:
_clutter_bind_constraint_set_coordinate (bind, g_value_get_enum (value));
break;
case PROP_OFFSET:
_clutter_bind_constraint_set_offset (bind, g_value_get_float (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
clutter_bind_constraint_get_property (GObject *gobject,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
ClutterBindConstraint *bind = CLUTTER_BIND_CONSTRAINT (gobject);
switch (prop_id)
{
case PROP_SOURCE:
g_value_set_object (value, bind->source);
break;
case PROP_COORDINATE:
g_value_set_enum (value, bind->coordinate);
break;
case PROP_OFFSET:
g_value_set_float (value, bind->offset);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (gobject, prop_id, pspec);
break;
}
}
static void
clutter_bind_constraint_class_init (ClutterBindConstraintClass *klass)
{
GObjectClass *gobject_class = G_OBJECT_CLASS (klass);
GParamSpec *pspec;
gobject_class->set_property = clutter_bind_constraint_set_property;
gobject_class->get_property = clutter_bind_constraint_get_property;
/**
* ClutterBindConstraint:source:
*
* The #ClutterActor used as the source for the binding
*
* Since: 1.4
*/
pspec = g_param_spec_object ("source",
"Source",
"The source of the binding",
CLUTTER_TYPE_ACTOR,
CLUTTER_PARAM_READWRITE |
G_PARAM_CONSTRUCT);
g_object_class_install_property (gobject_class, PROP_SOURCE, pspec);
/**
* ClutterBindConstraint:coordinate:
*
* The coordinate to be bound
*
* Since: 1.4
*/
pspec = g_param_spec_enum ("coordinate",
"Coordinate",
"The coordinate to bind",
CLUTTER_TYPE_BIND_COORDINATE,
CLUTTER_BIND_X,
CLUTTER_PARAM_READWRITE |
G_PARAM_CONSTRUCT);
g_object_class_install_property (gobject_class, PROP_COORDINATE, pspec);
/**
* ClutterBindConstraint:offset:
*
* The offset, in pixels, to be applied to the binding
*
* Since: 1.4
*/
pspec = g_param_spec_float ("offset",
"Offset",
"The offset in pixels to apply to the binding",
-G_MAXFLOAT, G_MAXFLOAT,
0.0f,
CLUTTER_PARAM_READWRITE |
G_PARAM_CONSTRUCT);
g_object_class_install_property (gobject_class, PROP_OFFSET, pspec);
}
static void
clutter_bind_constraint_init (ClutterBindConstraint *self)
{
self->source = NULL;
self->coordinate = CLUTTER_BIND_X;
self->offset = 0.0f;
}
/**
* clutter_bind_constraint_new:
* @source: the #ClutterActor to use as the source of the binding
* @coordinate: the coordinate to bind
* @offset: the offset to apply to the binding, in pixels
*
* Creates a new constraint, binding a #ClutterActor's position to
* the given @coordinate of the position of @source
*
* Return value: the newly created #ClutterBindConstraint
*
* Since: 1.4
*/
ClutterConstraint *
clutter_bind_constraint_new (ClutterActor *source,
ClutterBindCoordinate coordinate,
gfloat offset)
{
g_return_val_if_fail (CLUTTER_IS_ACTOR (source), NULL);
return g_object_new (CLUTTER_TYPE_BIND_CONSTRAINT,
"source", source,
"coordinate", coordinate,
"offset", offset,
NULL);
}