[gtk/matthiasc/for-master] testsuite: Improve coverage for GdkDisplayManager

[Matthias Clasen <matthiasc src gnome org>]

commit eb95d820b72a5fa354c314ec6190e4cd997e2624
Author: Matthias Clasen <mclasen redhat com>
Date:   Sat Oct 31 15:15:19 2020 -0400

    testsuite: Improve coverage for GdkDisplayManager

 testsuite/gdk/displaymanager.c | 55 ++++++++++++++++++++++++++++++++++++++++++
 testsuite/gdk/meson.build      |  1 +
 2 files changed, 56 insertions(+)
---
diff --git a/testsuite/gdk/displaymanager.c b/testsuite/gdk/displaymanager.c
new file mode 100644
index 0000000000..ce7c0d974f
--- /dev/null
+++ b/testsuite/gdk/displaymanager.c
@@ -0,0 +1,55 @@
+#include <gtk/gtk.h>
+
+static void
+test_basic (void)
+{
+  GdkDisplayManager *manager;
+  GdkDisplay *d, *d2;
+  GSList *list;
+
+  manager = gdk_display_manager_get ();
+  g_assert_nonnull (manager);
+
+  d = gdk_display_manager_get_default_display (manager);
+  g_assert_nonnull (d);
+  g_object_get (manager, "default-display", &d2, NULL);
+  g_assert_true (d == d2);
+  g_object_unref (d2);
+
+  list = gdk_display_manager_list_displays (manager);
+  g_assert_nonnull (g_slist_find (list, d));
+  g_slist_free (list);
+}
+
+static void
+test_set_default (void)
+{
+  GdkDisplayManager *manager;
+  GdkDisplay *d, *d2;
+  const char *name;
+
+  manager = gdk_display_manager_get ();
+  g_assert_nonnull (manager);
+
+  d = gdk_display_manager_get_default_display (manager);
+  name = gdk_display_get_name (d);
+  d2 = gdk_display_manager_open_display (manager, name);
+  g_object_set (manager, "default-display", d2, NULL);
+
+  d = gdk_display_manager_get_default_display (manager);
+  g_assert_true (d == d2);
+}
+
+int
+main (int argc, char *argv[])
+{
+  g_test_init (&argc, &argv, NULL);
+
+  /* Open default display */
+  gdk_display_open (NULL);
+
+  g_test_add_func ("/displaymanager/basic", test_basic);
+  g_test_add_func ("/displaymanager/set-default", test_set_default);
+
+  return g_test_run ();
+}
diff --git a/testsuite/gdk/meson.build b/testsuite/gdk/meson.build
index aa93f8384d..008b6269a2 100644
--- a/testsuite/gdk/meson.build
+++ b/testsuite/gdk/meson.build
@@ -6,6 +6,7 @@ tests = [
   'cairo',
   'clipboard',
   'display',
+  'displaymanager',
   'encoding',
   'keysyms',
   'memorytexture',