<para>The <seecref="M:Gtk.CellArea.FocusChanged"/> event utilizes this delegate:</para>
<para>Event data is passed via the <seecref="T:Gtk.FocusChangedArgs"/> parameter.</para>
<para>To attach a <seecref="T:Gtk.FocusChangedHandler"/> to an event, add the FocusChangedHandler instance to the event. The methods referenced by the FocusChangedHandler instance are invoked whenever the event is raised, until the FocusChangedHandler is removed from the event.</para>