> When an instance of this class is set as non editable, the secondary icon
> ("edit-clear"... or something related) is still present and lets too to
> remove the text... that is probably, as I said, a non desirable feature
> (while the object is set as non editable).
Probably worth to try it with GTK+. If the same issue is there, then
it's a bug in GTK+ (IMO)