private void updateDisplay() {
		need = getWhatNeedsDone();
		boolean done = need.length == 0;
		convertAction.setEnabled(!done);
		doAllAction.setEnabled(!done);
		highlightAction.setEnabled(!done);
		exportAction.setEnabled(done);
		if (done)
			directionLabel
					.setText("Conversion done.  Press \"Export\" to use.");
		else
			directionLabel.setText(need.length
					+ " production(s) must be converted.");
	}