wayland: Fix desktop background

- Disable X11BackgroundActor in wayland
- wayland compositor: Identify background windows created by
csd-background and stack them correctly in the bottom_window_group.

Author: mtwebster

src/compositor/compositor.c

@@ -600,15 +600,19 @@ meta_compositor_manage (MetaCompositor *compositor)
   priv->top_window_group = meta_window_group_new (display);
   priv->bottom_window_group = meta_window_group_new (display);
   priv->feedback_group = meta_window_group_new (display);
-  priv->background_actor = meta_x11_background_actor_new_for_display (display);
+
+  if (!meta_is_wayland_compositor ())
+    {
+      priv->background_actor = meta_x11_background_actor_new_for_display (display);
+      clutter_actor_add_child (priv->window_group, priv->background_actor);
+    }
+
+  clutter_actor_add_child (priv->window_group, priv->bottom_window_group);
 
   // This needs to remain stacked just above the background actor in the window group.
   // So sync_actor_stacking() has to be able to reference it. The deskletManager
   // will take this and finish setting it up.
   priv->desklet_container = clutter_actor_new ();
-
-  clutter_actor_add_child (priv->window_group, priv->background_actor);
-  clutter_actor_add_child (priv->window_group, priv->bottom_window_group);
   clutter_actor_add_child (priv->window_group, priv->desklet_container);
   clutter_actor_add_child (priv->stage, priv->window_group);
   clutter_actor_add_child (priv->stage, priv->top_window_group);
@@ -954,7 +958,7 @@ sync_actor_stacking (MetaCompositor *compositor)
         }
     }
 
-  g_list_free (children);
+  g_clear_pointer (&children, g_list_free);
 
   if (!reordered)
     {
@@ -989,6 +993,31 @@ sync_actor_stacking (MetaCompositor *compositor)
   // Then the bottom window group (which META_WINDOW_DESKTOP windows like nemo-desktop's get placed in).
   clutter_actor_set_child_below_sibling (priv->window_group, priv->bottom_window_group, NULL);
 
+  if (meta_is_wayland_compositor ())
+    {
+      children = clutter_actor_get_children (priv->bottom_window_group);
+      for (tmp = children; tmp != NULL; tmp = tmp->next)
+        {
+          MetaWindowActor *child = tmp->data;
+          MetaWindow *mw = meta_window_actor_get_meta_window (child);
+
+          if (mw != NULL)
+            {
+              // CsdBackground manager sets _NET_WM_STATE_BELOW (gtk_window_set_keep_below)
+              // This sets its stack layer to META_LAYER_BOTTOM, so we can keep these below
+              // the nemo-desktop, etc..
+              MetaStackLayer layer = meta_window_get_default_layer (mw);
+
+              if (layer == META_LAYER_BOTTOM)
+                {
+                  clutter_actor_set_child_below_sibling (priv->bottom_window_group, CLUTTER_ACTOR (child), NULL);
+                }
+            }
+        }
+
+        g_list_free (children);
+    }
+
   // and finally backgrounds..
 
   /* we prepended the backgrounds above so the last actor in the list
@@ -1719,6 +1748,11 @@ meta_get_x11_background_actor_for_display (MetaDisplay *display)
   MetaCompositorPrivate *priv =
     meta_compositor_get_instance_private (display->compositor);
 
+  if (meta_is_wayland_compositor ())
+    {
+      return NULL;
+    }
+
   return priv->background_actor;
 }
 

src/x11/meta-x11-background-actor.c

@@ -534,6 +534,9 @@ meta_x11_background_actor_new_for_display (MetaDisplay *display)
 
   g_return_val_if_fail (META_IS_DISPLAY (display), NULL);
 
+  if (meta_is_wayland_compositor ())
+    return NULL;
+
   self = g_object_new (META_TYPE_X11_BACKGROUND_ACTOR, NULL);
   priv = self->priv;
 
@@ -567,7 +570,6 @@ meta_x11_background_actor_update (MetaDisplay *display)
 {
   MetaX11Display *x11_display;
   MetaDisplayBackground *background;
-  MetaCompositor *compositor;
   Atom type;
   int format;
   gulong nitems;
@@ -577,7 +579,6 @@ meta_x11_background_actor_update (MetaDisplay *display)
 
   x11_display = meta_display_get_x11_display (display);
   background = meta_display_background_get (display);
-  compositor = meta_display_get_compositor (display);
 
   root_pixmap_id = None;
   if (!XGetWindowProperty (meta_x11_display_get_xdisplay (x11_display),
@@ -666,29 +667,3 @@ meta_x11_background_actor_screen_size_changed (MetaDisplay *x11_display)
 
   update_wrap_mode (background);
 }
-
-static MetaDisplayBackground *
-display_background_get (MetaDisplay *display)
-{
-  MetaDisplayBackground *background;
-
-  background = g_object_get_data (G_OBJECT (display), "meta-display-background");
-  if (background == NULL)
-    {
-      ClutterActor *stage;
-
-      background = g_new0 (MetaDisplayBackground, 1);
-
-      background->x11_display = meta_display_get_x11_display (display);
-      g_object_set_data_full (G_OBJECT (display), "meta-screen-background",
-                              background, (GDestroyNotify) free_display_background);
-
-      stage = meta_get_stage_for_display (display);
-      g_signal_connect (stage, "notify::background-color",
-                        G_CALLBACK (on_notify_stage_color), background);
-
-      meta_x11_background_actor_update (display);
-    }
-
-  return background;
-}