<signal name="activate" handler="pref_changed_cb"/>
<signal name="focus_out_event" handler="pref_changed_event_cb"/>
<signal name="value_changed" handler="pref_changed_cb"/>
<signal name="activate" handler="pref_changed_cb"/>
<signal name="focus_out_event" handler="pref_changed_event_cb"/>
<signal name="value_changed" handler="pref_changed_cb"/>