ui: Add xemu notifications interface

ui/xemu-notifications.h

@@ -0,0 +1,38 @@
+/*
+ * xemu Notification Management
+ *
+ * Helper functions for other subsystems to queue a notification for the user,
+ * which can be displayed by the HUD.
+ *
+ * Copyright (C) 2020 Matt Borgerson
+ *
+ * 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 XEMU_NOTIFICATION
+#define XEMU_NOTIFICATION
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+// Simple API to show a message on the screen when some event happens
+void xemu_queue_notification(const char *msg);
+void xemu_queue_error_message(const char *msg);
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif