GCC can catch errors when it knows that a variadic function must be
ended with NULL. Let's use the glib macro encapsulating the GCC
attribute to clutter_animator_set() and clutter_state_set().
A bogus ClutterInterpolation argument had been carried from
clutter_animator_set_interpolation to clutter_animator_get_interpolation
in copy and paste.
When asking a key for its target value we also ask the developer to pass
in an initialized GValue - but we don't make it easy to know the type of
the GValue. A developer has to ask the GObject class for the GParamSpec
and then initialize the GValue, instead.
Since we know the type of the GValue we should provide a getter for it.
We should also allow developers to throw at us GValue with compatible and
transformable types.
Finally, all the accessors should be constified.
ClutterAnimator is a class for managing the animation of multiple
properties of multiple actors over time with keyframing of values.
The Animator class is meant to be used to effectively describe
animations using the ClutterScript definition format, and to construct
complex implicit animations from the ground up.
Signed-off-by: Emmanuele Bassi <ebassi@linux.intel.com>