charWidth = getFontMetrics(getFont()).charWidth('m');
    ToolBar(ImViewerControl controller, ImViewerModel model)    {        if (controller == null) throw new NullPointerException("No control.");        if (model == null) throw new NullPointerException("No model.");        this.controller = controller;            this.model = model;        charWidth = getFontMetrics(getFont()).charWidth('m');        initComponents();    }