window: Add meta_window_lower_with_transients()

The only thing x11-specific about the existing code is that it is only
used to implement titlebar actions on server-side decorations.

We are about to bring that functionality to wayland, so move the code
into MetaWayland.

https://gitlab.gnome.org/GNOME/mutter/-/issues/602

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1944>

src/core/window.c

@@ -5176,6 +5176,62 @@ meta_window_lower (MetaWindow  *window)
   meta_stack_lower (window->display->stack, window);
 }
 
+static gboolean
+lower_window_and_transients (MetaWindow *window,
+                             gpointer    user_data)
+{
+  MetaWorkspaceManager *workspace_manager = window->display->workspace_manager;
+
+  meta_window_lower (window);
+
+  meta_window_foreach_transient (window, lower_window_and_transients, NULL);
+
+  if (meta_prefs_get_raise_on_click ())
+    {
+      /* Move window to the back of the focusing workspace's MRU list.
+       * Do extra sanity checks to avoid possible race conditions.
+       * (Borrowed from window.c.)
+       */
+      if (workspace_manager->active_workspace &&
+          meta_window_located_on_workspace (window,
+                                            workspace_manager->active_workspace))
+        {
+          GList *link;
+          link = g_list_find (workspace_manager->active_workspace->mru_list,
+                              window);
+          g_assert (link);
+
+          workspace_manager->active_workspace->mru_list =
+            g_list_remove_link (workspace_manager->active_workspace->mru_list,
+                                link);
+          g_list_free (link);
+
+          workspace_manager->active_workspace->mru_list =
+            g_list_append (workspace_manager->active_workspace->mru_list,
+                           window);
+        }
+    }
+
+  return FALSE;
+}
+
+void
+meta_window_lower_with_transients (MetaWindow *window,
+                                   uint32_t    timestamp)
+{
+  MetaWorkspaceManager *workspace_manager = window->display->workspace_manager;
+
+  lower_window_and_transients (window, NULL);
+
+ /* Rather than try to figure that out whether we just lowered
+  * the focus window, assume that's always the case. (Typically,
+  * this will be invoked via keyboard action or by a mouse action;
+  * in either case the window or a modal child will have been focused.) */
+  meta_workspace_focus_default_window (workspace_manager->active_workspace,
+                                       NULL,
+                                       timestamp);
+}
+
 /*
  * Move window to the requested workspace; append controls whether new WS
  * should be created if one does not exist.

src/meta/window.h

@@ -311,6 +311,10 @@ void        meta_window_raise              (MetaWindow  *window);
 META_EXPORT
 void        meta_window_lower              (MetaWindow  *window);
 
+META_EXPORT
+void        meta_window_lower_with_transients (MetaWindow *window,
+                                               uint32_t    timestamp);
+
 META_EXPORT
 const char *meta_window_get_title (MetaWindow *window);
 

src/x11/meta-x11-window-control.c

@@ -61,62 +61,14 @@ meta_x11_wm_queue_frame_resize (MetaX11Display *x11_display,
   meta_window_frame_size_changed (window);
 }
 
-static gboolean
-lower_window_and_transients (MetaWindow *window,
-                             gpointer   data)
-{
-  MetaWorkspaceManager *workspace_manager = window->display->workspace_manager;
-
-  meta_window_lower (window);
-
-  meta_window_foreach_transient (window, lower_window_and_transients, NULL);
-
-  if (meta_prefs_get_raise_on_click ())
-    {
-      /* Move window to the back of the focusing workspace's MRU list.
-       * Do extra sanity checks to avoid possible race conditions.
-       * (Borrowed from window.c.)
-       */
-      if (workspace_manager->active_workspace &&
-          meta_window_located_on_workspace (window,
-                                            workspace_manager->active_workspace))
-        {
-          GList* link;
-          link = g_list_find (workspace_manager->active_workspace->mru_list,
-                              window);
-          g_assert (link);
-
-          workspace_manager->active_workspace->mru_list =
-            g_list_remove_link (workspace_manager->active_workspace->mru_list,
-                                link);
-          g_list_free (link);
-
-          workspace_manager->active_workspace->mru_list =
-            g_list_append (workspace_manager->active_workspace->mru_list,
-                           window);
-        }
-    }
-
-  return FALSE;
-}
-
 void
 meta_x11_wm_user_lower_and_unfocus (MetaX11Display *x11_display,
                                     Window          frame_xwindow,
                                     uint32_t        timestamp)
 {
   MetaWindow *window = window_from_frame (x11_display, frame_xwindow);
-  MetaWorkspaceManager *workspace_manager = window->display->workspace_manager;
 
-  lower_window_and_transients (window, NULL);
+  meta_window_lower_with_transients (window, timestamp);
-
- /* Rather than try to figure that out whether we just lowered
-  * the focus window, assume that's always the case. (Typically,
-  * this will be invoked via keyboard action or by a mouse action;
-  * in either case the window or a modal child will have been focused.) */
-  meta_workspace_focus_default_window (workspace_manager->active_workspace,
-                                       NULL,
-                                       timestamp);
 }
 
 void