clutter: avoid g_signal_emit_by_name() from ClutterActor

g_signal_emit_by_name() is used to emit signals on ClutterContainer when
actors are removed or added. It happens to do various interface lookups
which are a bit unneccessary and can allocate memory.

Simply using emission wrappers makes all of that go away.

https://gitlab.gnome.org/GNOME/mutter/merge_requests/1083

clutter/clutter/cally/cally-actor.c

@@ -600,10 +600,11 @@ cally_actor_real_remove_actor (ClutterActor *container,
   g_return_val_if_fail (CLUTTER_IS_ACTOR (actor), 0);
 
   atk_parent = ATK_OBJECT (data);
-  atk_child = clutter_actor_get_accessible (actor);
 
-  if (atk_child)
+  if (clutter_actor_has_accessible (actor))
     {
+      atk_child = clutter_actor_get_accessible (actor);
+
       g_value_init (&values.old_value, G_TYPE_POINTER);
       g_value_set_pointer (&values.old_value, atk_parent);
 

clutter/clutter/clutter-actor.c

@@ -631,7 +631,7 @@
 #include "clutter-color-static.h"
 #include "clutter-color.h"
 #include "clutter-constraint-private.h"
-#include "clutter-container.h"
+#include "clutter-container-private.h"
 #include "clutter-content-private.h"
 #include "clutter-debug.h"
 #include "clutter-easing.h"
@@ -4582,7 +4582,7 @@ clutter_actor_remove_child_internal (ClutterActor                 *self,
 
   /* we need to emit the signal before dropping the reference */
   if (emit_actor_removed)
-    g_signal_emit_by_name (self, "actor-removed", child);
+    _clutter_container_emit_actor_removed (CLUTTER_CONTAINER (self), child);
 
   if (notify_first_last)
     {
@@ -13226,7 +13226,7 @@ clutter_actor_add_child_internal (ClutterActor              *self,
     }
 
   if (emit_actor_added)
-    g_signal_emit_by_name (self, "actor-added", child);
+    _clutter_container_emit_actor_added (CLUTTER_CONTAINER (self), child);
 
   if (notify_first_last)
     {
@@ -21192,3 +21192,14 @@ clutter_actor_create_texture_paint_node (ClutterActor *self,
 
   return node;
 }
+
+gboolean
+clutter_actor_has_accessible (ClutterActor *actor)
+{
+  g_return_val_if_fail (CLUTTER_IS_ACTOR (actor), FALSE);
+
+  if (CLUTTER_ACTOR_GET_CLASS (actor)->has_accessible)
+    return CLUTTER_ACTOR_GET_CLASS (actor)->has_accessible (actor);
+
+  return TRUE;
+}

clutter/clutter/clutter-actor.h

@@ -299,10 +299,11 @@ struct _ClutterActorClass
 
   gboolean (* touch_event)          (ClutterActor         *self,
                                      ClutterTouchEvent    *event);
+  gboolean (* has_accessible)       (ClutterActor         *self);
 
   /*< private >*/
   /* padding for future expansion */
-  gpointer _padding_dummy[26];
+  gpointer _padding_dummy[25];
 };
 
 /**
@@ -380,6 +381,8 @@ CLUTTER_EXPORT
 const gchar *                   clutter_actor_get_name                          (ClutterActor                *self);
 CLUTTER_EXPORT
 AtkObject *                     clutter_actor_get_accessible                    (ClutterActor                *self);
+CLUTTER_EXPORT
+gboolean                        clutter_actor_has_accessible                    (ClutterActor                *self);
 
 CLUTTER_EXPORT
 gboolean                        clutter_actor_is_visible                        (ClutterActor                *self);

clutter/clutter/clutter-container-private.h

@@ -0,0 +1,36 @@
+/*
+ * Clutter.
+ *
+ * An OpenGL based 'interactive canvas' library.
+ *
+ * Copyright 2020 Red Hat, Inc.
+ *
+ * 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/>.
+ */
+
+#ifndef __CLUTTER_CONTAINER_PRIVATE_H__
+#define __CLUTTER_CONTAINER_PRIVATE_H__
+
+#include <clutter/clutter-container.h>
+
+G_BEGIN_DECLS
+
+void _clutter_container_emit_actor_added   (ClutterContainer *container,
+                                            ClutterActor     *actor);
+void _clutter_container_emit_actor_removed (ClutterContainer *container,
+                                            ClutterActor     *actor);
+
+G_END_DECLS
+
+#endif /* __CLUTTER_CONTAINER_PRIVATE_H__ */

clutter/clutter/clutter-container.c

@@ -37,6 +37,7 @@
 
 #include "clutter-actor-private.h"
 #include "clutter-child-meta.h"
+#include "clutter-container-private.h"
 #include "clutter-debug.h"
 #include "clutter-main.h"
 #include "clutter-marshal.h"
@@ -1250,3 +1251,23 @@ clutter_container_child_notify (ClutterContainer *container,
                                                          child,
                                                          pspec);
 }
+
+void
+_clutter_container_emit_actor_added (ClutterContainer *container,
+                                     ClutterActor     *actor)
+{
+  g_return_if_fail (CLUTTER_IS_CONTAINER (container));
+  g_return_if_fail (CLUTTER_IS_ACTOR (actor));
+
+  g_signal_emit (container, container_signals[ACTOR_ADDED], 0, actor);
+}
+
+void
+_clutter_container_emit_actor_removed (ClutterContainer *container,
+                                       ClutterActor     *actor)
+{
+  g_return_if_fail (CLUTTER_IS_CONTAINER (container));
+  g_return_if_fail (CLUTTER_IS_ACTOR (actor));
+
+  g_signal_emit (container, container_signals[ACTOR_REMOVED], 0, actor);
+}