// ********************************* create_background_graphic

        void create_background_graphic()
        {
            if (background != null)
            {
                background = background.DeleteGraphicsBuffer();
            }
            background = new ZeroitWin8MarqueeHorizontalGraphicsBuffer();
            background.CreateGraphicsBuffer(Control_Width,
                                            control_height);
            background.Graphic.SmoothingMode     = Smoothing;
            background.Graphic.TextRenderingHint = TextRendering;
        }
        // ********************************** WinHR_create_indicator_graphic

        void WinHR_create_indicator_graphic()
        {
            if (indicator != null)
            {
                indicator = indicator.DeleteGraphicsBuffer();
            }
            indicator = new ZeroitWin8MarqueeHorizontalGraphicsBuffer();
            indicator.CreateGraphicsBuffer(Control_Width,
                                           control_height);
            indicator.Graphic.SmoothingMode     = Smoothing;
            indicator.Graphic.TextRenderingHint = TextRendering;
        }
        // ******************************************** WinHR_memory_cleanup

        void WinHR_memory_cleanup()
        {
            // DeleteGraphicsBuffer
            // returns null
            if (background != null)
            {
                background = background.DeleteGraphicsBuffer();
            }

            if (indicator != null)
            {
                indicator = indicator.DeleteGraphicsBuffer();
            }

            if (WinHR_timer != null)
            {
                if (WinHR_timer.Enabled)
                {
                    WinHR_timer.Enabled = false;
                }
                WinHR_timer.Dispose();
                WinHR_timer = null;
            }
        }