org.freedesktop.locale1 — The D-Bus interface of systemd-localed
systemd-localed.service(8) is a system service that can be used to control the system locale and keyboard mapping from user programs. This page describes the D-Bus interface.
The service exposes the following interfaces on the bus:
node /org/freedesktop/locale1 {
  interface org.freedesktop.locale1 {
    methods:
      SetLocale(in  as locale,
                in  b interactive);
      SetVConsoleKeyboard(in  s keymap,
                          in  s keymap_toggle,
                          in  b convert,
                          in  b interactive);
      SetX11Keyboard(in  s layout,
                     in  s model,
                     in  s variant,
                     in  s options,
                     in  b convert,
                     in  b interactive);
    properties:
      readonly as Locale = ['...', ...];
      readonly s X11Layout = '...';
      readonly s X11Model = '...';
      readonly s X11Variant = '...';
      readonly s X11Options = '...';
      readonly s VConsoleKeymap = '...';
      readonly s VConsoleKeymapToggle = '...';
  };
  interface org.freedesktop.DBus.Peer { ... };
  interface org.freedesktop.DBus.Introspectable { ... };
  interface org.freedesktop.DBus.Properties { ... };
};
If you set a new system locale all old system locale settings will be dropped and the new settings will be saved to disk. The locale will also be passed to the system manager, and subsequently started daemons will inherit the new system locale. Note that already running daemons will not learn about the new value.
The SetVConsoleKeyboard() method may be used to set the key mapping for the
      virtual console. Similarly, SetX11Keyboard() may be used to set the default key
      mapping of any X11 servers.
Note that SetVConsoleKeyboard() instantly applies the new key mapping to the
      console, while SetX11Keyboard() simply sets a default that may be used by later
      sessions.
The boolean argument convert may be set to optionally convert the console
      keyboard configuration to X11 keyboard mappings and vice versa. If true and
      SetVConsoleKeyboard() is used, the nearest X11 keyboard setting for the chosen
      console setting is set. If true and SetX11Keyboard() is used, the nearest console
      keyboard setting for the chosen X11 setting is set. Hence, it is usually sufficient to call only one of the
      two functions.
For graphical UIs that need to set the system keyboard mapping simply invoke
      SetX11Keyboard(), set convert=true and ignore
      SetVConsoleKeyboard().
Use the empty string for the keymap parameters you wish not to set.
The interactive boolean parameters can be used to control whether
      polkit
      should interactively ask the user for authentication credentials if required.
Whenever the system locale or keymap is changed via the daemon,
      PropertyChanged signals are sent out to which clients can subscribe.
The system locale is shown in the Locale property. It is an array containing
      environment-variable-assignment-like strings. The following strings are known:
      LANG=, LC_CTYPE=, LC_NUMERIC=,
      LC_TIME=, LC_COLLATE=, LC_MONETARY=,
      LC_MESSAGES=, LC_PAPER=, LC_NAME=,
      LC_ADDRESS=, LC_TELEPHONE=, LC_MEASUREMENT=,
      LC_IDENTIFICATION=.
The X11Layout, X11Model, X11Variant, and
      X11Options properties show values configurable with
      SetX11Keyboard() described above (or SetVConsoleKeyboard()
      with convert=true). The VConsoleKeymap and
      VConsoleKeymapToggle properties show values configurable with
      SetVConsoleKeyboard() (or SetX11Keyboard() with
      convert=true).
Changing the system locale or keymap using this interface is authenticated via polkit. The
      polkit action for SetLocale() is
      org.freedesktop.locale1.set-locale. The polkit action for
      SetX11Keyboard() and SetVConsoleKeyboard() is
      org.freedesktop.locale1.set-keyboard.
Example 1. Introspect org.freedesktop.locale1 on the bus
$ gdbus introspect --system \ --dest org.freedesktop.locale1 \ --object-path /org/freedesktop/locale1