Adding suggestions to a Gtk::TextView

["Søren Hauberg" <hauberg gmail com>]

Hi All,
  I'm trying to create an interface where the user types commands into
a Gtk::TextView. To this I'd like to add Tab-completion to this
interface, such that when Tab is pressed a list of possible
completions is shown -- just like you see in most IDE's. My initial
thought was to add a ChildAnchor to the TextBuffer, and then add some
widget to the anchor that displays the suggestions. However,
  1) I can't seem to figure out how to actually add a widget at an anchor.
  2) I don't know which widget would be most suitable to display the suggestions

I'd appriciate any thoughts as I'm quite new to gtkmm,
Søren