tests: Add public test monitor API

This will allow gnome-shell perf tests to create and destroy virtual
test monitors whenever it needs to.

Part-of: <https://gitlab.gnome.org/GNOME/mutter/-/merge_requests/2824>

src/tests/meson.build

@@ -12,6 +12,7 @@ mutter_test_sources = [
   'meta-ref-test.h',
   'meta-sensors-proxy-mock.c',
   'meta-sensors-proxy-mock.h',
+  'meta-test-monitor.c',
   'meta-test-utils.c',
   'meta-test-utils.h',
 ]

src/tests/meta-test-monitor.c

@@ -0,0 +1,102 @@
+/*
+ * Copyright 2023 Red Hat
+ *
+ * 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 "meta-test/meta-test-monitor.h"
+
+#include "backends/meta-virtual-monitor.h"
+#include "backends/meta-monitor-manager-private.h"
+#include "meta/meta-backend.h"
+
+struct _MetaTestMonitor
+{
+  GObject parent;
+
+  MetaVirtualMonitor *virtual_monitor;
+};
+
+G_DEFINE_TYPE (MetaTestMonitor, meta_test_monitor, G_TYPE_OBJECT)
+
+static void
+meta_test_monitor_dispose (GObject *object)
+{
+  MetaTestMonitor *test_monitor = META_TEST_MONITOR (object);
+
+  g_clear_object (&test_monitor->virtual_monitor);
+
+  G_OBJECT_CLASS (meta_test_monitor_parent_class)->dispose (object);
+}
+
+static void
+meta_test_monitor_class_init (MetaTestMonitorClass *klass)
+{
+  GObjectClass *object_class = G_OBJECT_CLASS (klass);
+
+  object_class->dispose = meta_test_monitor_dispose;
+}
+
+static void
+meta_test_monitor_init (MetaTestMonitor *test_monitor)
+{
+}
+
+MetaTestMonitor *
+meta_test_monitor_new (MetaContext  *context,
+                       int           width,
+                       int           height,
+                       float         refresh_rate,
+                       GError      **error)
+{
+  MetaBackend *backend = meta_context_get_backend (context);
+  MetaMonitorManager *monitor_manager = meta_backend_get_monitor_manager (backend);
+  g_autoptr (MetaVirtualMonitorInfo) monitor_info = NULL;
+  static int serial_count = 0x10000;
+  g_autofree char *serial = NULL;
+  MetaVirtualMonitor *virtual_monitor;
+  MetaTestMonitor *test_monitor;
+
+  serial = g_strdup_printf ("0x%x", serial_count++);
+  monitor_info = meta_virtual_monitor_info_new (width, height, refresh_rate,
+                                                "MetaTestVendor",
+                                                "MetaTestMonitor",
+                                                serial);
+  virtual_monitor = meta_monitor_manager_create_virtual_monitor (monitor_manager,
+                                                                 monitor_info,
+                                                                 error);
+  if (!virtual_monitor)
+    return NULL;
+
+  g_idle_add_once ((GSourceOnceFunc) meta_monitor_manager_reload,
+                   monitor_manager);
+
+  test_monitor = g_object_new (META_TYPE_TEST_MONITOR, NULL);
+  test_monitor->virtual_monitor = virtual_monitor;
+
+  return test_monitor;
+}
+
+/**
+ * meta_test_monitor_destroy:
+ * @test_monitor: (transfer full): A #MetaTestMonitor
+ */
+void
+meta_test_monitor_destroy (MetaTestMonitor *test_monitor)
+{
+  g_object_run_dispose (G_OBJECT (test_monitor));
+  g_object_unref (test_monitor);
+}

src/tests/meta-test/meson.build

@@ -2,6 +2,7 @@ mutter_test_includesubdir = join_paths(pkgname, 'meta-test')
 
 mutter_test_public_headers = files([
   'meta-context-test.h',
+  'meta-test-monitor.h',
 ])
 
 install_headers(mutter_test_public_headers,

src/tests/meta-test/meta-test-monitor.h

@@ -0,0 +1,41 @@
+/*
+ * Copyright 2023 Red Hat
+ *
+ * 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/>.
+ */
+
+#ifndef META_TEST_MONITOR_H
+#define META_TEST_MONITOR_H
+
+#include <glib.h>
+#include <glib-object.h>
+#include <meta/common.h>
+#include <meta/meta-context.h>
+
+#define META_TYPE_TEST_MONITOR (meta_test_monitor_get_type ())
+META_EXPORT
+G_DECLARE_FINAL_TYPE (MetaTestMonitor, meta_test_monitor,
+                      META, TEST_MONITOR, GObject)
+
+META_EXPORT
+MetaTestMonitor * meta_test_monitor_new (MetaContext  *context,
+                                         int           width,
+                                         int           height,
+                                         float         refresh_rate,
+                                         GError      **error);
+
+META_EXPORT
+void meta_test_monitor_destroy (MetaTestMonitor *test_monitor);
+
+#endif /* META_TEST_MONITOR_H */