state: added clutter_state_key_get_property_type

A function to retrieve the type of the value stored in a key, the
equivalent already exists for ClutterAnimator.

clutter/clutter-state.c

@@ -1503,6 +1503,28 @@ clutter_state_key_get_target_state_name (const ClutterStateKey *state_key)
   return state_key->target_state->name;
 }
 
+/**
+ * clutter_state_key_get_property_type:
+ * @key: a #ClutterStateKey
+ *
+ * Retrieves the #GType of the property a key applies to
+ *
+ * You can use this type to initialize the #GValue to pass to
+ * clutter_state_key_get_value()
+ *
+ * Return value: the #GType of the property
+ *
+ * Since: 1.4
+ */
+GType
+clutter_state_key_get_property_type (const ClutterStateKey *key)
+{
+  g_return_val_if_fail (key != NULL, G_TYPE_INVALID);
+
+  return G_VALUE_TYPE (&key->value);
+}
+
+
 /**
  * clutter_state_set_duration:
  * @state: a #ClutterState