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mutter-performance-source/clutter/clutter-animatable.c
Emmanuele Bassi 6fff1bcdc6 [animatable] Allow validation in ::animate_property
The Animatable interface implementation will always have the computed
value applied, whilst the non-Animatable objects go through the
interval validation first to avoid incurring in assertions and
warnings.

The Animatable::animate_property() should also be able to validate the
property it's supposed to interpolate, and eventually discard it. This
requires adding a return value to the virtual function (and its wrapper
function).

The Animation code will then apply the computed value only if the
animate_property() returns TRUE -- unifying the code path with the
non-Animatable objects.
2009-05-27 13:01:31 +01:00

126 lines
4.8 KiB
C

/*
* Clutter.
*
* An OpenGL based 'interactive canvas' library.
*
* Copyright (C) 2009 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-animatable
* @short_description: Interface for animatable classes
*
* #ClutterAnimatable is an interface that allows a #GObject class
* to control how a #ClutterAnimation will animate a property.
*
* Each #ClutterAnimatable should implement the animate_property()
* virtual function of the interface to compute the animation state
* between two values of an interval depending on a progress factor,
* expressed as a floating point value.
*
* If a #ClutterAnimatable is animated by a #ClutterAnimation
* instance, the #ClutterAnimation will call
* clutter_animatable_animate_property() passing the name of the
* currently animated property; the initial and final values of
* the animation interval; the progress factor. The #ClutterAnimatable
* implementation should return the computed value for the animated
* property.
*
* #ClutterAnimatable is available since Clutter 1.0
*/
#ifdef HAVE_CONFIG_H
#include "config.h"
#endif
#include "clutter-animatable.h"
#include "clutter-debug.h"
#include "clutter-private.h"
GType
clutter_animatable_get_type (void)
{
static GType a_type = 0;
if (G_UNLIKELY (a_type == 0))
a_type = g_type_register_static_simple (G_TYPE_INTERFACE,
I_("ClutterAnimatable"),
sizeof (ClutterAnimatableIface),
NULL, 0, NULL, 0);
return a_type;
}
/**
* clutter_animatable_animate_property:
* @animatable: a #ClutterAnimatable
* @animation: a #ClutterAnimation
* @property_name: the name of the animated property
* @initial_value: the initial value of the animation interval
* @final_value: the final value of the animation interval
* @progress: the progress factor
* @value: return location for the animation value
*
* Calls the animate_property() virtual function for @animatable.
*
* The @initial_value and @final_value #GValue<!-- -->s must contain
* the same type; @value must have been initialized to the same
* type of @initial_value and @final_value.
*
* All implementation of the #ClutterAnimatable interface must
* implement this function.
*
* Return value: %TRUE if the value has been validated and can
* be applied to the #ClutterAnimatable, and %FALSE otherwise
*
* Since: 1.0
*/
gboolean
clutter_animatable_animate_property (ClutterAnimatable *animatable,
ClutterAnimation *animation,
const gchar *property_name,
const GValue *initial_value,
const GValue *final_value,
gdouble progress,
GValue *value)
{
gboolean res;
g_return_val_if_fail (CLUTTER_IS_ANIMATABLE (animatable), FALSE);
g_return_val_if_fail (CLUTTER_IS_ANIMATION (animation), FALSE);
g_return_val_if_fail (property_name != NULL, FALSE);
g_return_val_if_fail (initial_value != NULL && final_value != NULL, FALSE);
g_return_val_if_fail (G_VALUE_TYPE (initial_value) != G_TYPE_INVALID, FALSE);
g_return_val_if_fail (G_VALUE_TYPE (final_value) != G_TYPE_INVALID, FALSE);
g_return_val_if_fail (value != NULL, FALSE);
g_return_val_if_fail (G_VALUE_TYPE (value) == G_VALUE_TYPE (initial_value) &&
G_VALUE_TYPE (value) == G_VALUE_TYPE (final_value),
FALSE);
res =
CLUTTER_ANIMATABLE_GET_IFACE (animatable)->animate_property (animatable,
animation,
property_name,
initial_value,
final_value,
progress,
value);
return res;
}