behaviour: Implement the implicit alpha parsing

ClutterBehaviour should implement the Scriptable interface
and parse ClutterAlpha when implicitly defined, instead of
having this ad hoc code inside ClutterScriptParser itself.

After all, only ClutterBehaviour supports Alpha defined
implicitly.

clutter/clutter-behaviour.c

@@ -71,12 +71,14 @@
 #include "config.h"
 #endif
 
-#include "clutter-main.h"
 #include "clutter-actor.h"
 #include "clutter-behaviour.h"
 #include "clutter-debug.h"
-#include "clutter-private.h"
+#include "clutter-main.h"
 #include "clutter-marshal.h"
+#include "clutter-private.h"
+#include "clutter-scriptable.h"
+#include "clutter-script-private.h"
 
 /**
  * clutter_knot_copy:
@@ -157,9 +159,13 @@ clutter_knot_get_type (void)
   return our_type;
 }
 
-G_DEFINE_ABSTRACT_TYPE (ClutterBehaviour,
-                        clutter_behaviour,
-                        G_TYPE_OBJECT);
+static void clutter_scriptable_iface_init (ClutterScriptableIface *iface);
+
+G_DEFINE_ABSTRACT_TYPE_WITH_CODE (ClutterBehaviour,
+                                  clutter_behaviour,
+                                  G_TYPE_OBJECT,
+                                  G_IMPLEMENT_INTERFACE (CLUTTER_TYPE_SCRIPTABLE,
+                                                         clutter_scriptable_iface_init));
 
 struct _ClutterBehaviourPrivate
 {
@@ -188,6 +194,36 @@ static guint behave_signals[LAST_SIGNAL] = { 0 };
                CLUTTER_TYPE_BEHAVIOUR,             \
                ClutterBehaviourPrivate))
 
+static gboolean
+clutter_behaviour_parse_custom_node (ClutterScriptable *scriptable,
+                                     ClutterScript     *script,
+                                     GValue            *value,
+                                     const gchar       *name,
+                                     JsonNode          *node)
+{
+  if (strncmp (name, "alpha", 5) == 0)
+    {
+      GObject *alpha;
+
+      alpha = _clutter_script_parse_alpha (script, node);
+      if (alpha != NULL)
+        {
+          g_value_init (value, CLUTTER_TYPE_ALPHA);
+          g_value_set_object (value, alpha);
+
+          return TRUE;
+        }
+    }
+
+  return FALSE;
+}
+
+static void
+clutter_scriptable_iface_init (ClutterScriptableIface *iface)
+{
+  iface->parse_custom_node = clutter_behaviour_parse_custom_node;
+}
+
 static void
 clutter_behaviour_dispose (GObject *gobject)
 {

clutter/clutter-script-parser.c

@@ -816,8 +816,8 @@ resolve_alpha_func (const gchar *name)
 }
 
 GObject *
-clutter_script_parse_alpha (ClutterScript *script,
-                            JsonNode      *node)
+_clutter_script_parse_alpha (ClutterScript *script,
+                             JsonNode      *node)
 {
   GObject *retval = NULL;
   JsonObject *object;
@@ -1068,21 +1068,6 @@ clutter_script_parse_node (ClutterScript *script,
 
           if (g_type_is_a (p_type, G_TYPE_OBJECT))
             {
-              /* ClutterAlpha are handled a little bit
-               * differently, since they can be implicit
-               */
-              if (g_type_is_a (p_type, CLUTTER_TYPE_ALPHA))
-                {
-                  GObject *alpha;
-
-                  alpha = clutter_script_parse_alpha (script, node);
-                  if (alpha)
-                    {
-                      g_value_set_object (value, alpha);
-                      return TRUE;
-                    }
-                }
-
               /* default GObject handling: we get the id and
                * retrieve the ObjectInfo for it; since the object
                * definitions are parsed leaf-first we are guaranteed

clutter/clutter-script-private.h

@@ -121,8 +121,8 @@ gboolean clutter_script_parse_geometry    (ClutterScript   *script,
 gboolean clutter_script_parse_color       (ClutterScript   *script,
                                            JsonNode        *node,
                                            ClutterColor    *color);
-GObject *clutter_script_parse_alpha       (ClutterScript   *script,
-                                           JsonNode        *node);
+GObject *_clutter_script_parse_alpha       (ClutterScript   *script,
+                                            JsonNode        *node);
 
 void _clutter_script_construct_object (ClutterScript *script,
                                        ObjectInfo    *oinfo);