public void actionPerformed(ActionEvent event) {
        String command = event.getActionCommand();
        if (command.equals("GridStroke")) {
            attemptGridStrokeSelection();
        }
        else if (command.equals("GridPaint")) {
            attemptGridPaintSelection();
        }
        else if (command.equals("AutoRangeOnOff")) {
            toggleAutoRange();
        }
        else if (command.equals("MinimumRange")) {
            validateMinimum();
        }
        else if (command.equals("MaximumRange")) {
            validateMaximum();
        }
        else {
            // pass to the super-class for handling
            super.actionPerformed(event);