public ScrollListWidget(
        WidgetGroup parentGroup, 
        WidgetFactory widgetFactory,
        ScrollListStyle style,
        float x, 
        float y)
        : base(parentGroup, style.Width, style.Height, x, y)
    {
        m_widgetFactory = widgetFactory;
        m_widgetList = new List<IWidget>();
        m_scrollIndex = 0;

        m_scrollFrame = new ImageWidget(this, style.Width, style.Height, style.Background, 0.0f, 0.0f);

        m_scrollUpButton =
            new ButtonWidget(this, style.ButtonStyle, 0, 0, "Previous");
        m_scrollUpButton.SetLocalPosition(
            m_scrollFrame.Width / 2 - m_scrollUpButton.Width / 2,
            BORDER_WIDTH);
        m_scrollUpButton.Visible = false;

        m_scrollDownButton =
            new ButtonWidget(this, style.ButtonStyle, 0, 0, "Next");
        m_scrollDownButton.SetLocalPosition(
            m_scrollUpButton.LocalX,
            m_scrollFrame.Height - m_scrollDownButton.Height - BORDER_WIDTH);
        m_scrollDownButton.Visible = false;
    }
    public ScrollListWidget(
        WidgetGroup parentGroup,
        WidgetFactory widgetFactory,
        ScrollListStyle style,
        float x,
        float y)
        : base(parentGroup, style.Width, style.Height, x, y)
    {
        m_widgetFactory = widgetFactory;
        m_widgetList    = new List <IWidget>();
        m_scrollIndex   = 0;

        m_scrollFrame = new ImageWidget(this, style.Width, style.Height, style.Background, 0.0f, 0.0f);

        m_scrollUpButton =
            new ButtonWidget(this, style.ButtonStyle, 0, 0, "Previous");
        m_scrollUpButton.SetLocalPosition(
            m_scrollFrame.Width / 2 - m_scrollUpButton.Width / 2,
            BORDER_WIDTH);
        m_scrollUpButton.Visible = false;

        m_scrollDownButton =
            new ButtonWidget(this, style.ButtonStyle, 0, 0, "Next");
        m_scrollDownButton.SetLocalPosition(
            m_scrollUpButton.LocalX,
            m_scrollFrame.Height - m_scrollDownButton.Height - BORDER_WIDTH);
        m_scrollDownButton.Visible = false;
    }