keymap: Keep keymap fd management in one place

At the same time, reduce the distance between this and the Xwayland handling branch.

eek/eek-keyboard.h

@@ -1,17 +1,17 @@
-/* 
+/*
  * Copyright (C) 2010-2011 Daiki Ueno <ueno@unixuser.org>
  * Copyright (C) 2010-2011 Red Hat, Inc.
- * 
+ *
  * This library is free software; you can redistribute it and/or
  * modify it under the terms of the GNU Lesser General Public License
  * as published by the Free Software Foundation; either version 2 of
  * the License, or (at your option) any later version.
- * 
+ *
  * This library 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
  * Lesser General Public License for more details.
- * 
+ *
  * You should have received a copy of the GNU Lesser General Public
  * License along with this library; if not, write to the Free Software
  * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA
@@ -32,19 +32,20 @@
 
 G_BEGIN_DECLS
 
+/// Keymap container for Rust interoperability.
+struct keymap {
+    uint32_t fd; // keymap formatted as XKB string
+    size_t fd_len; // length of the data inside keymap_fd
+};
+
 /// Keyboard state holder
 struct _LevelKeyboard {
     struct squeek_layout *layout; // owned
-    struct xkb_keymap *keymap; // owned
-    int keymap_fd; // keymap formatted as XKB string
-    size_t keymap_len; // length of the data inside keymap_fd
-
-    guint id; // as a key to layout choices
+    struct keymap keymap; // owned
 };
 typedef struct _LevelKeyboard LevelKeyboard;
 
-gchar *             eek_keyboard_get_keymap
-                                     (LevelKeyboard *keyboard);
+gchar *eek_keyboard_get_keymap(LevelKeyboard *keyboard);
 
 LevelKeyboard*
 level_keyboard_new (struct squeek_layout *layout);