mutter/clutter/clutter-bind-constraint.c
Emmanuele Bassi a75c02a5d6 constraints: Allow Align and Bind sources to be NULL
Since constructing AlignConstraint and BindConstraint instances could be
deferred (think ClutterScript) we need to make their :source properties
setters accept NULL. This does not break the constraints because they
need to handle that condition in case they actor to which they are
applied is destroyed and somebody is holding a reference on them anyway.
2010-06-17 17:33:10 +01:00

435 lines
12 KiB
C

/*
* 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>
*/
/**
* 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 (bind->source == NULL)
return;
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_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: (allow-none): the #ClutterActor to use as the source of
* the binding, or %NULL
* @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 (source == NULL || CLUTTER_IS_ACTOR (source), NULL);
return g_object_new (CLUTTER_TYPE_BIND_CONSTRAINT,
"source", source,
"coordinate", coordinate,
"offset", offset,
NULL);
}
/**
* clutter_bind_constraint_set_source:
* @constraint: a #ClutterBindConstraint
* @source: (allow-none): a #ClutterActor, or %NULL to unset the source
*
* Sets the source #ClutterActor for the constraint
*
* Since: 1.4
*/
void
clutter_bind_constraint_set_source (ClutterBindConstraint *constraint,
ClutterActor *source)
{
ClutterActor *old_source;
g_return_if_fail (CLUTTER_IS_BIND_CONSTRAINT (constraint));
g_return_if_fail (source == NULL || CLUTTER_IS_ACTOR (source));
old_source = constraint->source;
if (old_source != NULL)
{
g_signal_handlers_disconnect_by_func (old_source,
G_CALLBACK (source_destroyed),
constraint);
g_signal_handlers_disconnect_by_func (old_source,
G_CALLBACK (source_position_changed),
constraint);
}
constraint->source = source;
if (constraint->source != NULL)
{
g_signal_connect (constraint->source, "notify",
G_CALLBACK (source_position_changed),
constraint);
g_signal_connect (constraint->source, "destroy",
G_CALLBACK (source_destroyed),
constraint);
update_actor_position (constraint);
}
g_object_notify (G_OBJECT (constraint), "source");
}
/**
* clutter_bind_constraint_get_source:
* @constraint: a #ClutterBindConstraint
*
* Retrieves the #ClutterActor set using clutter_bind_constraint_set_source()
*
* Return value: (transfer none): a pointer to the source actor
*
* Since: 1.4
*/
ClutterActor *
clutter_bind_constraint_get_source (ClutterBindConstraint *constraint)
{
g_return_val_if_fail (CLUTTER_IS_BIND_CONSTRAINT (constraint), NULL);
return constraint->source;
}
/**
* clutter_bind_constraint_set_coordinate:
* @constraint: a #ClutterBindConstraint
* @coordinate: the coordinate to bind
*
* Sets the coordinate to bind in the constraint
*
* Since: 1.4
*/
void
clutter_bind_constraint_set_coordinate (ClutterBindConstraint *constraint,
ClutterBindCoordinate coordinate)
{
g_return_if_fail (CLUTTER_IS_BIND_CONSTRAINT (constraint));
if (constraint->coordinate == coordinate)
return;
constraint->coordinate = coordinate;
update_actor_position (constraint);
g_object_notify (G_OBJECT (constraint), "coordinate");
}
/**
* clutter_bind_constraint_get_coordinate:
* @constraint: a #ClutterBindConstraint
*
* Retrieves the bound coordinate of the constraint
*
* Return value: the bound coordinate
*
* Since: 1.4
*/
ClutterBindCoordinate
clutter_bind_constraint_get_coordinate (ClutterBindConstraint *constraint)
{
g_return_val_if_fail (CLUTTER_IS_BIND_CONSTRAINT (constraint),
CLUTTER_BIND_X);
return constraint->coordinate;
}
/**
* clutter_bind_constraint_set_offset:
* @constraint: a #ClutterBindConstraint
* @offset: the offset to apply, in pixels
*
* Sets the offset to be applied to the constraint
*
* Since: 1.4
*/
void
clutter_bind_constraint_set_offset (ClutterBindConstraint *constraint,
gfloat offset)
{
g_return_if_fail (CLUTTER_IS_BIND_CONSTRAINT (constraint));
if (fabs (constraint->offset - offset) < 0.00001f)
return;
constraint->offset = offset;
update_actor_position (constraint);
g_object_notify (G_OBJECT (constraint), "offset");
}
/**
* clutter_bind_constraint_get_offset:
* @constraint: a #ClutterBindConstraint
*
* Retrieves the offset set using clutter_bind_constraint_set_offset()
*
* Return value: the offset, in pixels
*
* Since: 1.4
*/
gfloat
clutter_bind_constraint_get_offset (ClutterBindConstraint *bind)
{
g_return_val_if_fail (CLUTTER_IS_BIND_CONSTRAINT (bind), 0.0);
return bind->offset;
}