fcitx-dbus-status addon provides DBus interface such as
 org.fcitx.Fcitx.Status, and provides Get/Set/Changed methods on it.
 By accessing these interfaces, you can monitor or control status of
 input method with external command line tool such as dbus-send. As a
 typical use case, you can set "katakana" mode in the following
 example for fcitx-mozc.
 .
 dbus-send \
  --dest=org.fcitx.Fcitx \
  --type=method_call \
  --print-reply \
  /Status \
  org.fcitx.Fcitx.Status.Set \
  string:"mozc-composition-mode" \
  string:"katakana"