def resynch_editor(self):
        """ Resynchronizes the contents of the editor when the object trait
            changes externally to the editor.
        """
        button = self._button
        if button is not None:
            label = self.factory.label
            if label == "":
                label = user_name_for(self.name)

            button.setText(label)
            button.setEnabled(isinstance(self.value, HasTraits))