[mutter] wayland: Move tree updating to the shell surface role

[Robert Mader <rmader src gnome org>]

commit 5149e1e43a33552244dff73c144e832e8dd217cb
Author: Jonas Ådahl <jadahl gmail com>
Date:   Tue Oct 8 23:32:37 2019 +0200

    wayland: Move tree updating to the shell surface role
    
    The shell surface role is the one where subsurfaces may exist, and it
    has direct relation to the MetaWindowActorWayland which currently has
    the subsurface stacking logic.
    
    Instead of directly finding the window actor when dealing with
    subsurfaces, notify the parent surface that the subsurface state
    changed, so that it can outsource the application of this information to
    the role. For subsurface roles, this simply means forward upward to the
    parent; for shell surface roles, this means regenerate the surface actor
    layering.
    
    This allows us to move away from accessing the window directly from the
    surface, which in turn allows us to change the ownership structure of
    windows.
    
    https://gitlab.gnome.org/GNOME/mutter/merge_requests/835

 src/compositor/meta-window-actor-wayland.c | 11 -----------
 src/compositor/meta-window-actor-wayland.h |  1 -
 src/wayland/meta-wayland-shell-surface.c   | 19 +++++++++++++++++++
 src/wayland/meta-wayland-subsurface.c      | 22 ++++++++++++++--------
 src/wayland/meta-wayland-surface.c         | 18 ++++++++++++++++++
 src/wayland/meta-wayland-surface.h         |  3 +++
 6 files changed, 54 insertions(+), 20 deletions(-)
---
diff --git a/src/compositor/meta-window-actor-wayland.c b/src/compositor/meta-window-actor-wayland.c
index f145f54c3..4cdf8fe0e 100644
--- a/src/compositor/meta-window-actor-wayland.c
+++ b/src/compositor/meta-window-actor-wayland.c
@@ -91,17 +91,6 @@ meta_window_actor_wayland_rebuild_surface_tree (MetaWindowActor *actor)
                    actor);
 }
 
-MetaWindowActor *
-meta_window_actor_wayland_from_surface (MetaWaylandSurface *surface)
-{
-  if (surface->window)
-    return meta_window_actor_from_window (surface->window);
-  else if (surface->sub.parent)
-    return meta_window_actor_wayland_from_surface (surface->sub.parent);
-  else
-    return NULL;
-}
-
 static void
 meta_window_actor_wayland_assign_surface_actor (MetaWindowActor  *actor,
                                                 MetaSurfaceActor *surface_actor)
diff --git a/src/compositor/meta-window-actor-wayland.h b/src/compositor/meta-window-actor-wayland.h
index d7e1b7808..d94de8106 100644
--- a/src/compositor/meta-window-actor-wayland.h
+++ b/src/compositor/meta-window-actor-wayland.h
@@ -33,6 +33,5 @@ G_DECLARE_FINAL_TYPE (MetaWindowActorWayland,
                       MetaWindowActor)
 
 void meta_window_actor_wayland_rebuild_surface_tree (MetaWindowActor *actor);
-MetaWindowActor * meta_window_actor_wayland_from_surface (MetaWaylandSurface *surface);
 
 #endif /*META_WINDOW_ACTOR_WAYLAND_H */
diff --git a/src/wayland/meta-wayland-shell-surface.c b/src/wayland/meta-wayland-shell-surface.c
index c2022a736..aa3e397ac 100644
--- a/src/wayland/meta-wayland-shell-surface.c
+++ b/src/wayland/meta-wayland-shell-surface.c
@@ -24,6 +24,7 @@
 #include "wayland/meta-wayland-shell-surface.h"
 
 #include "compositor/meta-surface-actor-wayland.h"
+#include "compositor/meta-window-actor-wayland.h"
 #include "wayland/meta-wayland-actor-surface.h"
 #include "wayland/meta-wayland-buffer.h"
 #include "wayland/meta-wayland-subsurface.h"
@@ -165,6 +166,22 @@ meta_wayland_shell_surface_surface_apply_state (MetaWaylandSurfaceRole  *surface
     meta_wayland_surface_get_height (surface) * geometry_scale;
 }
 
+static void
+meta_wayland_shell_surface_notify_subsurface_state_changed (MetaWaylandSurfaceRole *surface_role)
+{
+  MetaWaylandSurface *surface =
+    meta_wayland_surface_role_get_surface (surface_role);
+  MetaWindow *window;
+  MetaWindowActor *window_actor;
+
+  window = surface->window;
+  if (!window)
+    return;
+
+  window_actor = meta_window_actor_from_window (window);
+  meta_window_actor_wayland_rebuild_surface_tree (window_actor);
+}
+
 static double
 meta_wayland_shell_surface_get_geometry_scale (MetaWaylandActorSurface *actor_surface)
 {
@@ -246,6 +263,8 @@ meta_wayland_shell_surface_class_init (MetaWaylandShellSurfaceClass *klass)
 
   surface_role_class->apply_state =
     meta_wayland_shell_surface_surface_apply_state;
+  surface_role_class->notify_subsurface_state_changed =
+    meta_wayland_shell_surface_notify_subsurface_state_changed;
 
   actor_surface_class->get_geometry_scale =
     meta_wayland_shell_surface_get_geometry_scale;
diff --git a/src/wayland/meta-wayland-subsurface.c b/src/wayland/meta-wayland-subsurface.c
index 3e5632010..d3afcf8af 100644
--- a/src/wayland/meta-wayland-subsurface.c
+++ b/src/wayland/meta-wayland-subsurface.c
@@ -139,7 +139,6 @@ meta_wayland_subsurface_parent_state_applied (MetaWaylandSubsurface *subsurface)
     {
       GSList *it;
       MetaWaylandSurface *parent;
-      MetaWindowActor *window_actor;
 
       parent = surface->sub.parent;
 
@@ -184,9 +183,7 @@ meta_wayland_subsurface_parent_state_applied (MetaWaylandSubsurface *subsurface)
       g_slist_free (surface->sub.pending_placement_ops);
       surface->sub.pending_placement_ops = NULL;
 
-      window_actor = meta_window_actor_wayland_from_surface (surface);
-      if (window_actor)
-        meta_window_actor_wayland_rebuild_surface_tree (window_actor);
+      meta_wayland_surface_notify_subsurface_state_changed (parent);
     }
 
   if (is_surface_effectively_synchronized (surface))
@@ -258,6 +255,16 @@ meta_wayland_subsurface_should_cache_state (MetaWaylandSurfaceRole *surface_role
   return TRUE;
 }
 
+static void
+meta_wayland_subsurface_notify_subsurface_state_changed (MetaWaylandSurfaceRole *surface_role)
+{
+  MetaWaylandSurface *surface =
+    meta_wayland_surface_role_get_surface (surface_role);
+  MetaWaylandSurface *parent = surface->sub.parent;
+
+  return meta_wayland_surface_notify_subsurface_state_changed (parent);
+}
+
 static double
 meta_wayland_subsurface_get_geometry_scale (MetaWaylandActorSurface *actor_surface)
 {
@@ -313,6 +320,8 @@ meta_wayland_subsurface_class_init (MetaWaylandSubsurfaceClass *klass)
 
   surface_role_class->get_toplevel = meta_wayland_subsurface_get_toplevel;
   surface_role_class->should_cache_state = meta_wayland_subsurface_should_cache_state;
+  surface_role_class->notify_subsurface_state_changed =
+    meta_wayland_subsurface_notify_subsurface_state_changed;
 
   actor_surface_class->get_geometry_scale =
     meta_wayland_subsurface_get_geometry_scale;
@@ -519,7 +528,6 @@ wl_subcompositor_get_subsurface (struct wl_client   *client,
   MetaWaylandSurface *surface = wl_resource_get_user_data (surface_resource);
   MetaWaylandSurface *parent = wl_resource_get_user_data (parent_resource);
   MetaWindow *toplevel_window;
-  MetaWindowActor *window_actor;
 
   if (surface->wl_subsurface)
     {
@@ -564,9 +572,7 @@ wl_subcompositor_get_subsurface (struct wl_client   *client,
   g_node_append (parent->subsurface_branch_node,
                  surface->subsurface_branch_node);
 
-  window_actor = meta_window_actor_wayland_from_surface (surface);
-  if (window_actor)
-    meta_window_actor_wayland_rebuild_surface_tree (window_actor);
+  meta_wayland_surface_notify_subsurface_state_changed (parent);
 }
 
 static const struct wl_subcompositor_interface meta_wayland_subcompositor_interface = {
diff --git a/src/wayland/meta-wayland-surface.c b/src/wayland/meta-wayland-surface.c
index 2b01a2acb..de3502b2e 100644
--- a/src/wayland/meta-wayland-surface.c
+++ b/src/wayland/meta-wayland-surface.c
@@ -1843,6 +1843,24 @@ meta_wayland_surface_should_cache_state (MetaWaylandSurface *surface)
   return meta_wayland_surface_role_should_cache_state (surface->role);
 }
 
+static void
+meta_wayland_surface_role_notify_subsurface_state_changed (MetaWaylandSurfaceRole *surface_role)
+{
+  MetaWaylandSurfaceRoleClass *klass;
+
+  klass = META_WAYLAND_SURFACE_ROLE_GET_CLASS (surface_role);
+  g_return_if_fail (klass->notify_subsurface_state_changed);
+
+  klass->notify_subsurface_state_changed (surface_role);
+}
+
+void
+meta_wayland_surface_notify_subsurface_state_changed (MetaWaylandSurface *surface)
+{
+  if (surface->role)
+    meta_wayland_surface_role_notify_subsurface_state_changed (surface->role);
+}
+
 MetaWaylandSurface *
 meta_wayland_surface_role_get_surface (MetaWaylandSurfaceRole *role)
 {
diff --git a/src/wayland/meta-wayland-surface.h b/src/wayland/meta-wayland-surface.h
index b75b0708d..b19a35832 100644
--- a/src/wayland/meta-wayland-surface.h
+++ b/src/wayland/meta-wayland-surface.h
@@ -62,6 +62,7 @@ struct _MetaWaylandSurfaceRoleClass
                                      MetaLogicalMonitor     *logical_monitor);
   MetaWaylandSurface * (*get_toplevel) (MetaWaylandSurfaceRole *surface_role);
   gboolean (*should_cache_state) (MetaWaylandSurfaceRole *surface_role);
+  void (*notify_subsurface_state_changed) (MetaWaylandSurfaceRole *surface_role);
 };
 
 struct _MetaWaylandSurfaceState
@@ -325,6 +326,8 @@ MetaSurfaceActor *  meta_wayland_surface_get_actor (MetaWaylandSurface *surface)
 
 void                meta_wayland_surface_notify_geometry_changed (MetaWaylandSurface *surface);
 
+void                meta_wayland_surface_notify_subsurface_state_changed (MetaWaylandSurface *surface);
+
 int                 meta_wayland_surface_get_width (MetaWaylandSurface *surface);
 int                 meta_wayland_surface_get_height (MetaWaylandSurface *surface);