'Extend selectionChanged to call completers selection_changed.'

def selectionChanged(self, selected, deselected):

    if (not self._active):
        return
    super().selectionChanged(selected, deselected)
    indexes = selected.indexes()
    if (not indexes):
        return
    data = str(self.model().data(indexes[0]))
    self.selection_changed.emit(data)
