[mutter] clutter/actor: Notify hidden actors about absolute allocation changes

[Jonas Ådahl <jadahl src gnome org>]

commit 9b39e37fee28d5dd6fbcadc11a40d118423573cb
Author: Jonas Dreßler <verdre v0yd nl>
Date:   Sun May 10 11:26:37 2020 +0200

    clutter/actor: Notify hidden actors about absolute allocation changes
    
    With commit 0eab73dc2e we introduced an optimization of not doing
    allocations for actors which are hidden. This broke the propagation of
    absolute origin changes to hidden actors, so if an actor is moved while
    its child is hidden, the child will not get
    priv->needs_compute_resource_scale set to TRUE, which means the resource
    scale won't be updated when the child gets mapped and shown again.
    
    Since we now have priv->absolute_origin_changed, we can simply check
    whether that is TRUE for our parent before bailing out of
    clutter_actor_allocate() and if it is, notify the whole hidden sub-tree
    about the absolute origin change.
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1247

 clutter/clutter/clutter-actor.c | 43 +++++++++++++++++++++++++++++++++--------
 1 file changed, 35 insertions(+), 8 deletions(-)
---
diff --git a/clutter/clutter/clutter-actor.c b/clutter/clutter/clutter-actor.c
index 15f7e11e5d..c0eb4a134f 100644
--- a/clutter/clutter/clutter-actor.c
+++ b/clutter/clutter/clutter-actor.c
@@ -2560,6 +2560,22 @@ clutter_actor_notify_if_geometry_changed (ClutterActor          *self,
   g_object_thaw_notify (obj);
 }
 
+static void
+absolute_allocation_changed (ClutterActor *actor)
+{
+  actor->priv->needs_compute_resource_scale = TRUE;
+}
+
+static ClutterActorTraverseVisitFlags
+absolute_allocation_changed_cb (ClutterActor *actor,
+                                int           depth,
+                                gpointer      user_data)
+{
+  absolute_allocation_changed (actor);
+
+  return CLUTTER_ACTOR_TRAVERSE_VISIT_CONTINUE;
+}
+
 /*< private >
  * clutter_actor_set_allocation_internal:
  * @self: a #ClutterActor
@@ -2606,7 +2622,7 @@ clutter_actor_set_allocation_internal (ClutterActor           *self,
   priv->absolute_origin_changed |= x1_changed || y1_changed;
 
   if (priv->absolute_origin_changed || x2_changed || y2_changed)
-    priv->needs_compute_resource_scale = TRUE;
+    absolute_allocation_changed (self);
 
   if (x1_changed ||
       y1_changed ||
@@ -10111,11 +10127,26 @@ clutter_actor_allocate (ClutterActor          *self,
       return;
     }
 
-  if (!clutter_actor_is_visible (self))
-    return;
-
   priv = self->priv;
 
+  priv->absolute_origin_changed = priv->parent
+                                ? priv->parent->priv->absolute_origin_changed
+                                : FALSE;
+
+  if (!CLUTTER_ACTOR_IS_VISIBLE (self))
+    {
+      if (priv->absolute_origin_changed)
+        {
+          _clutter_actor_traverse (self,
+                                   CLUTTER_ACTOR_TRAVERSE_DEPTH_FIRST,
+                                   absolute_allocation_changed_cb,
+                                   NULL,
+                                   NULL);
+        }
+
+      goto out;
+    }
+
   old_allocation = priv->allocation;
   real_allocation = *box;
 
@@ -10147,10 +10178,6 @@ clutter_actor_allocate (ClutterActor          *self,
   size_changed = (real_allocation.x2 != old_allocation.x2 ||
                   real_allocation.y2 != old_allocation.y2);
 
-  priv->absolute_origin_changed = priv->parent
-                                ? priv->parent->priv->absolute_origin_changed
-                                : FALSE;
-
   stage_allocation_changed =
     priv->absolute_origin_changed || origin_changed || size_changed;