tests/test-client: Add 'fullscreen' and 'unfullscreen' commands

This needs some hand holding when calculating the "full" size of the
window, as the titlebar isn't actually shown.

https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/1171

src/tests/meson.build

@@ -143,6 +143,7 @@ stacking_tests = [
   'set-parent-exported',
   'restore-size',
   'unmaximize-new-size',
+  'fullscreen-maximize',
 ]
 
 foreach stacking_test: stacking_tests

src/tests/test-client.c

@@ -246,6 +246,11 @@ static int
 calculate_titlebar_height (GtkWindow *window)
 {
   GtkWidget *titlebar;
+  GdkWindow *gdk_window;
+
+  gdk_window = gtk_widget_get_window (GTK_WIDGET (window));
+  if (gdk_window_get_state (gdk_window) & GDK_WINDOW_STATE_FULLSCREEN)
+    return 0;
 
   titlebar = gtk_window_get_titlebar (window);
   if (!titlebar)
@@ -733,6 +738,34 @@ process_line (const char *line)
 
       gtk_window_unmaximize (GTK_WINDOW (window));
     }
+  else if (strcmp (argv[0], "fullscreen") == 0)
+    {
+      if (argc != 2)
+        {
+          g_print ("usage: fullscreen <id>\n");
+          goto out;
+        }
+
+      GtkWidget *window = lookup_window (argv[1]);
+      if (!window)
+        goto out;
+
+      gtk_window_fullscreen (GTK_WINDOW (window));
+    }
+  else if (strcmp (argv[0], "unfullscreen") == 0)
+    {
+      if (argc != 2)
+        {
+          g_print ("usage: unfullscreen <id>\n");
+          goto out;
+        }
+
+      GtkWidget *window = lookup_window (argv[1]);
+      if (!window)
+        goto out;
+
+      gtk_window_unfullscreen (GTK_WINDOW (window));
+    }
   else if (strcmp (argv[0], "assert_size") == 0)
     {
       int expected_width;

src/tests/test-runner.c

@@ -600,6 +600,8 @@ test_case_do (TestCase *test,
            strcmp (argv[0], "unminimize") == 0 ||
            strcmp (argv[0], "maximize") == 0 ||
            strcmp (argv[0], "unmaximize") == 0 ||
+           strcmp (argv[0], "fullscreen") == 0 ||
+           strcmp (argv[0], "unfullscreen") == 0 ||
            strcmp (argv[0], "destroy") == 0)
     {
       if (argc != 2)