mutter/clutter/clutter-behaviour.c
Emmanuele Bassi 237496fa75 2006-11-17 Emmanuele Bassi <ebassi@openedhand.com>
* clutter/clutter-behaviour-path.h:
	* clutter/clutter-behaviour-path.c: Add a "knot-reached" signal,
	which is emitted when the path reaches a node in the nodes list;
	flesh out the documentation a bit; sync the parameters names
	so that gtk-doc doesn't complain about missing stuff.

	* clutter/clutter-behaviour.h:
	* clutter/clutter-behaviour.c: Add the alpha value to the
	ClutterBehaviour::alpha_notify vfunc, so you don't have to
	get the value from the alpha inside the behaviour implementations;
	add more documentation.

	* clutter/clutter-alpha.c: Flesh out the description.

	* clutter/clutter-actor.h: Update the header.

	* clutter/clutter-behaviour-opacity.c:
	* clutter/clutter-behaviour-scale.c: Update docs.
2006-11-17 18:45:31 +00:00

284 lines
7.9 KiB
C

/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Authored By Matthew Allum <mallum@openedhand.com>
*
* Copyright (C) 2006 OpenedHand
*
* 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, write to the
* Free Software Foundation, Inc., 59 Temple Place - Suite 330,
* Boston, MA 02111-1307, USA.
*/
/**
* SECTION:clutter-behaviour
* @short_description: Class for providing behaviours to actors
*
* #ClutterBehaviour is the base class for implementing behaviours. A
* behaviour is a controller object for #ClutterActor<!-- -->s; you can
* use a behaviour to control one or more properties of an actor (such
* as its opacity, or its position). A #ClutterBehaviour is driven by
* an "alpha function" stored inside a #ClutterAlpha object; an alpha
* function is a function depending solely on time. The alpha function
* computes a value which is then applied to the properties of the
* actors driven by a behaviour.
*
* Clutter provides some pre-defined behaviours, like #ClutterBehaviourPath,
* which controls the position of a set of actors making them "walk" along
* a set of nodes; #ClutterBehaviourOpacity, which controls the opacity
* of a set of actors; #ClutterBehaviourScale, which controls the width
* and height of a set of actors.
*
* In order to implement a new behaviour you should subclass #ClutterBehaviour
* and override the "alpha_notify" virtual function; inside the overridden
* function you should obtain the alpha value from the #ClutterAlpha
* instance bound to the behaviour and apply it to the desiderd property
* (or properties) of every actor controlled by the behaviour.
*/
#include "config.h"
#include "clutter-actor.h"
#include "clutter-behaviour.h"
G_DEFINE_ABSTRACT_TYPE (ClutterBehaviour,
clutter_behaviour,
G_TYPE_OBJECT);
struct _ClutterBehaviourPrivate
{
ClutterAlpha *alpha;
guint notify_id;
GSList *actors;
};
enum
{
PROP_0,
PROP_ALPHA
};
enum {
SIGNAL_LAST
};
#define CLUTTER_BEHAVIOUR_GET_PRIVATE(obj) \
(G_TYPE_INSTANCE_GET_PRIVATE ((obj), \
CLUTTER_TYPE_BEHAVIOUR, \
ClutterBehaviourPrivate))
static void
clutter_behaviour_finalize (GObject *object)
{
ClutterBehaviour *self = CLUTTER_BEHAVIOUR (object);
clutter_behaviour_set_alpha (self, NULL);
g_slist_foreach (self->priv->actors, (GFunc) g_object_unref, NULL);
g_slist_free (self->priv->actors);
G_OBJECT_CLASS (clutter_behaviour_parent_class)->finalize (object);
}
static void
clutter_behaviour_set_property (GObject *object,
guint prop_id,
const GValue *value,
GParamSpec *pspec)
{
ClutterBehaviour *behaviour;
behaviour = CLUTTER_BEHAVIOUR(object);
switch (prop_id)
{
case PROP_ALPHA:
clutter_behaviour_set_alpha (behaviour, g_value_get_object (value));
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
clutter_behaviour_get_property (GObject *object,
guint prop_id,
GValue *value,
GParamSpec *pspec)
{
ClutterBehaviour *behaviour;
ClutterBehaviourPrivate *priv;
behaviour = CLUTTER_BEHAVIOUR(object);
priv = CLUTTER_BEHAVIOUR_GET_PRIVATE(behaviour);
switch (prop_id)
{
case PROP_ALPHA:
g_value_set_object (value, priv->alpha);
break;
default:
G_OBJECT_WARN_INVALID_PROPERTY_ID (object, prop_id, pspec);
break;
}
}
static void
clutter_behaviour_class_init (ClutterBehaviourClass *klass)
{
GObjectClass *object_class = G_OBJECT_CLASS (klass);
object_class->finalize = clutter_behaviour_finalize;
object_class->set_property = clutter_behaviour_set_property;
object_class->get_property = clutter_behaviour_get_property;
g_object_class_install_property (object_class,
PROP_ALPHA,
g_param_spec_object ("alpha",
"Alpha",
"Alpha Object to drive the behaviour",
CLUTTER_TYPE_ALPHA,
G_PARAM_CONSTRUCT |
G_PARAM_READWRITE));
g_type_class_add_private (klass, sizeof (ClutterBehaviourPrivate));
}
static void
clutter_behaviour_init (ClutterBehaviour *self)
{
ClutterBehaviourPrivate *priv;
self->priv = priv = CLUTTER_BEHAVIOUR_GET_PRIVATE (self);
}
void
clutter_behaviour_apply (ClutterBehaviour *behave,
ClutterActor *actor)
{
g_return_if_fail (CLUTTER_IS_BEHAVIOUR (behave));
g_return_if_fail (CLUTTER_IS_ACTOR (actor));
if (g_slist_find (behave->priv->actors, actor))
{
g_warning ("The behaviour of type %s already applies "
"to the actor of type %s",
g_type_name (G_OBJECT_TYPE (behave)),
g_type_name (G_OBJECT_TYPE (actor)));
return;
}
g_object_ref (actor);
behave->priv->actors = g_slist_prepend (behave->priv->actors, actor);
}
void
clutter_behaviour_remove (ClutterBehaviour *behave,
ClutterActor *actor)
{
g_return_if_fail (CLUTTER_IS_BEHAVIOUR (behave));
g_return_if_fail (CLUTTER_IS_ACTOR (actor));
if (!g_slist_find (behave->priv->actors, actor))
{
g_warning ("The behaviour of type %s does not apply "
"to the actor of type %s",
g_type_name (G_OBJECT_TYPE (behave)),
g_type_name (G_OBJECT_TYPE (actor)));
return;
}
g_object_unref (actor);
behave->priv->actors = g_slist_remove (behave->priv->actors, actor);
}
void
clutter_behaviour_actors_foreach (ClutterBehaviour *behave,
GFunc func,
gpointer userdata)
{
g_return_if_fail (CLUTTER_IS_BEHAVIOUR (behave));
g_return_if_fail (func != NULL);
g_slist_foreach (behave->priv->actors, func, userdata);
}
ClutterAlpha*
clutter_behaviour_get_alpha (ClutterBehaviour *behave)
{
g_return_val_if_fail (CLUTTER_IS_BEHAVIOUR (behave), NULL);
return behave->priv->alpha;
}
static void
notify_cb (GObject *object,
GParamSpec *param_spec,
ClutterBehaviour *behave)
{
ClutterBehaviourClass *klass;
klass = CLUTTER_BEHAVIOUR_GET_CLASS (behave);
if (klass->alpha_notify)
{
guint32 alpha_value;
alpha_value = clutter_alpha_get_alpha (behave->priv->alpha);
klass->alpha_notify (behave, alpha_value);
}
}
void
clutter_behaviour_set_alpha (ClutterBehaviour *behave,
ClutterAlpha *alpha)
{
ClutterBehaviourPrivate *priv;
g_return_if_fail (CLUTTER_IS_BEHAVIOUR (behave));
g_return_if_fail (CLUTTER_IS_ALPHA (alpha));
priv = behave->priv;
if (priv->notify_id)
{
g_signal_handler_disconnect (priv->alpha, priv->notify_id);
priv->notify_id = 0;
}
if (priv->alpha)
{
g_object_unref (priv->alpha);
priv->alpha = NULL;
}
if (alpha)
{
priv->alpha = alpha;
g_object_ref_sink (priv->alpha);
priv->notify_id = g_signal_connect (priv->alpha, "notify::alpha",
G_CALLBACK(notify_cb),
behave);
}
}