[mutter] clutter/actor: Only allocate when actor is mapped, not only visible

[Carlos Garnacho <carlosg src gnome org>]

commit 3bca29f3038d58f5f42978b2f7d3103f6119d565
Author: Jonas Dreßler <verdre v0yd nl>
Date:   Fri Oct 16 23:29:02 2020 +0200

    clutter/actor: Only allocate when actor is mapped, not only visible
    
    In theory there's no big difference between only handling mapped actors
    vs only handling visible actors in clutter_actor_allocate(): The
    function is called recursively starting with an actor that is attached
    to a stage, so it should only be called on mapped actors anyway.
    
    The behavior of skipping hidden actors was introduced as an optimization
    with commit 0eab73dc. Since the last commit, we handle
    enable_paint_unmapped a bit better and don't do unnecessary work when
    mapping or unmapping, so we can now be a bit stricter enforcing our
    invariants and only allow mapped actors in clutter_actor_allocate().
    
    We need to exclude toplevel actors from this check since the stage has a
    very different mapped state than normal actors, depending on the
    mappedness of the x11 window. Also we need to make an exception for
    clones (of course...): Those need their source actor to have an
    allocation, which means they might try to force-allocate it, and in that
    case we shouldn't bail out of clutter_actor_allocate().
    
    Also moving the clutter_actor_queue_relayout() call from
    clutter_actor_real_show() to clutter_actor_real_map() seems to fix a bug
    where we don't queue redraws/relayouts on children when a parent gets
    shown.
    
    Fixes https://gitlab.gnome.org/GNOME/gnome-shell/-/issues/2973
    
    https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1366

 clutter/clutter/clutter-actor.c | 33 ++++++++++++++-------------------
 1 file changed, 14 insertions(+), 19 deletions(-)
---
diff --git a/clutter/clutter/clutter-actor.c b/clutter/clutter/clutter-actor.c
index 8fde0f5503..a398986bf3 100644
--- a/clutter/clutter/clutter-actor.c
+++ b/clutter/clutter/clutter-actor.c
@@ -1635,6 +1635,13 @@ clutter_actor_real_map (ClutterActor *self)
           priv->needs_update_stage_views = FALSE;
           queue_update_stage_views (self);
         }
+
+      /* Avoid the early return in clutter_actor_queue_relayout() */
+      priv->needs_width_request = FALSE;
+      priv->needs_height_request = FALSE;
+      priv->needs_allocation = FALSE;
+
+      clutter_actor_queue_relayout (self);
     }
 
   /* notify on parent mapped before potentially mapping
@@ -1742,6 +1749,10 @@ clutter_actor_real_unmap (ClutterActor *self)
        */
      _clutter_paint_volume_init_static (&priv->last_paint_volume, NULL);
       priv->last_paint_volume_valid = TRUE;
+
+      if (priv->parent && !CLUTTER_ACTOR_IN_DESTRUCTION (priv->parent) &&
+          (!(priv->parent->flags & CLUTTER_ACTOR_NO_LAYOUT)))
+        clutter_actor_queue_relayout (priv->parent);
     }
 
   /* notify on parent mapped after potentially unmapping
@@ -1799,8 +1810,6 @@ clutter_actor_queue_shallow_relayout (ClutterActor *self)
 static void
 clutter_actor_real_show (ClutterActor *self)
 {
-  ClutterActorPrivate *priv = self->priv;
-
   if (CLUTTER_ACTOR_IS_VISIBLE (self))
     return;
 
@@ -1811,13 +1820,6 @@ clutter_actor_real_show (ClutterActor *self)
    * and the branch of the scene graph is in a stable state
    */
   clutter_actor_update_map_state (self, MAP_STATE_CHECK);
-
-  /* Avoid the early return in clutter_actor_queue_relayout() */
-  priv->needs_width_request = FALSE;
-  priv->needs_height_request = FALSE;
-  priv->needs_allocation = FALSE;
-
-  clutter_actor_queue_relayout (self);
 }
 
 static inline void
@@ -1938,8 +1940,6 @@ clutter_actor_is_visible (ClutterActor *self)
 static void
 clutter_actor_real_hide (ClutterActor *self)
 {
-  ClutterActorPrivate *priv = self->priv;
-
   if (!CLUTTER_ACTOR_IS_VISIBLE (self))
     return;
 
@@ -1950,13 +1950,6 @@ clutter_actor_real_hide (ClutterActor *self)
    * and the branch of the scene graph is in a stable state
    */
   clutter_actor_update_map_state (self, MAP_STATE_CHECK);
-
-  /* we queue a relayout unless the actor is inside a
-   * container that explicitly told us not to
-   */
-  if (priv->parent != NULL &&
-      (!(priv->parent->flags & CLUTTER_ACTOR_NO_LAYOUT)))
-    clutter_actor_queue_relayout (priv->parent);
 }
 
 /**
@@ -9576,7 +9569,9 @@ clutter_actor_allocate (ClutterActor          *self,
                                 ? priv->parent->priv->absolute_origin_changed
                                 : FALSE;
 
-  if (!CLUTTER_ACTOR_IS_VISIBLE (self))
+  if (!CLUTTER_ACTOR_IS_TOPLEVEL (self) &&
+      !CLUTTER_ACTOR_IS_MAPPED (self) &&
+      !clutter_actor_has_mapped_clones (self))
     {
       if (priv->absolute_origin_changed)
         {