window: Add internal meta_window_should_show() API

This, in contrast to meta_window_should_be_showing() reports whether a
window should be showing despite not being showable. This is useful to
know the intended visibility state that should happen in the immediate
future.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/3475>

src/core/window-private.h

@@ -684,8 +684,12 @@ void        meta_window_resize_frame_with_gravity (MetaWindow  *window,
 gboolean    meta_window_should_be_showing_on_workspace (MetaWindow    *window,
                                                         MetaWorkspace *workspace);
 
+META_EXPORT_TEST
 gboolean    meta_window_should_be_showing   (MetaWindow  *window);
 
+META_EXPORT_TEST
+gboolean    meta_window_should_show (MetaWindow  *window);
+
 void        meta_window_update_struts      (MetaWindow  *window);
 
 /* gets position we need to set to stay in current position,

src/core/window.c

@@ -1706,6 +1706,41 @@ meta_window_is_showable (MetaWindow *window)
   return TRUE;
 }
 
+/**
+ * meta_window_should_show_on_workspace:
+ *
+ * Tells whether a window should be showing on the passed workspace, without
+ * taking into account whether it can immediately be shown. Whether it can be
+ * shown or not depends on what windowing system it was created from.
+ *
+ * Returns: %TRUE if the window should show.
+ */
+static gboolean
+meta_window_should_show_on_workspace (MetaWindow    *window,
+                                      MetaWorkspace *workspace)
+{
+  return (meta_window_located_on_workspace (window, workspace) &&
+          meta_window_showing_on_its_workspace (window));
+}
+
+/**
+ * meta_window_should_show:
+ *
+ * Tells whether a window should be showing on the current workspace, without
+ * taking into account whether it can immediately be shown. Whether it can be
+ * shown or not depends on what windowing system it was created from.
+ *
+ * Returns: %TRUE if the window should show.
+ */
+gboolean
+meta_window_should_show (MetaWindow *window)
+{
+  MetaWorkspaceManager *workspace_manager = window->display->workspace_manager;
+  MetaWorkspace *active_workspace = workspace_manager->active_workspace;
+
+  return meta_window_should_show_on_workspace (window, active_workspace);
+}
+
 /**
  * meta_window_should_be_showing_on_workspace:
  *
@@ -1722,10 +1757,7 @@ meta_window_should_be_showing_on_workspace (MetaWindow    *window,
   if (!meta_window_is_showable (window))
     return FALSE;
 
-  /* Windows should be showing if they're located on the
+  return meta_window_should_show_on_workspace (window, workspace);
-   * workspace and they're showing on their own workspace. */
-  return (meta_window_located_on_workspace (window, workspace) &&
-          meta_window_showing_on_its_workspace (window));
 }
 
 /**

src/tests/wayland-test-clients/meson.build

@@ -66,6 +66,9 @@ wayland_test_clients = [
   {
     'name': 'subsurface-reparenting',
   },
+  {
+    'name': 'toplevel-show-states',
+  },
   {
     'name': 'xdg-activation',
   },

src/tests/wayland-test-clients/toplevel-show-states.c

@@ -0,0 +1,59 @@
+/*
+ * Copyright (C) 2024 Red Hat Inc.
+ *
+ * This program is free software; you can redistribute it and/or
+ * modify it under the terms of the GNU General Public License as
+ * published by the Free Software Foundation; either version 2 of the
+ * License, or (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program; if not, see <http://www.gnu.org/licenses/>.
+ */
+
+#include "config.h"
+
+#include <glib.h>
+#include <wayland-client.h>
+
+#include "wayland-test-client-utils.h"
+
+static gboolean running;
+
+static void
+on_surface_painted (WaylandDisplay *display,
+                    WaylandSurface *surface)
+{
+  test_driver_sync_point (display->test_driver, 1, NULL);
+  wl_display_roundtrip (display->display);
+  running = FALSE;
+}
+
+int
+main (int    argc,
+      char **argv)
+{
+  g_autoptr (WaylandDisplay) display = NULL;
+  g_autoptr (WaylandSurface) surface = NULL;
+
+  display = wayland_display_new (WAYLAND_DISPLAY_CAPABILITY_TEST_DRIVER |
+                                 WAYLAND_DISPLAY_CAPABILITY_XDG_SHELL_V6);
+  surface = wayland_surface_new (display, "showing-states", 100, 100, 0xffffffff);
+  wl_surface_commit (surface->wl_surface);
+
+  test_driver_sync_point (display->test_driver, 0, NULL);
+  wait_for_sync_event (display, 0);
+
+  g_signal_connect (display, "surface-painted",
+                    G_CALLBACK (on_surface_painted), NULL);
+
+  running = TRUE;
+  while (running)
+    wayland_display_dispatch (display);
+
+  return EXIT_SUCCESS;
+}

src/tests/wayland-unit-tests.c

@@ -844,6 +844,30 @@ xdg_foreign_set_parent_of (void)
   meta_wayland_test_client_finish (wayland_test_client);
 }
 
+static void
+toplevel_show_states (void)
+{
+  MetaWaylandTestClient *wayland_test_client;
+  MetaWindow *window;
+
+  wayland_test_client =
+    meta_wayland_test_client_new (test_context, "toplevel-show-states");
+
+  wait_for_sync_point (0);
+  window = find_client_window ("showing-states");
+
+  g_assert_true (meta_window_should_show (window));
+  g_assert_false (meta_window_should_be_showing (window));
+
+  meta_wayland_test_driver_emit_sync_event (test_driver, 0);
+  wait_for_sync_point (1);
+
+  g_assert_true (meta_window_should_show (window));
+  g_assert_true (meta_window_should_be_showing (window));
+
+  meta_wayland_test_client_finish (wayland_test_client);
+}
+
 static void
 on_before_tests (void)
 {
@@ -921,6 +945,8 @@ init_tests (void)
 #endif
   g_test_add_func ("/wayland/xdg-foreign/set-parent-of",
                    xdg_foreign_set_parent_of);
+  g_test_add_func ("/wayland/toplevel/show-states",
+                   toplevel_show_states);
 }
 
 int