ComponentFactory.Krypton.Toolkit.RenderStandard.DrawRibbonGroupCollapsedFrameBorder C# (CSharp) Method

        protected virtual IDisposable DrawRibbonGroupCollapsedFrameBorder(RenderContext context,
                                                                          Rectangle rect,
                                                                          PaletteState state,
                                                                          IPaletteRibbonBack palette,
                                                                          IDisposable memento)
        {
            if ((rect.Width > 0) && (rect.Height > 0))
            {
                Color c1 = palette.GetRibbonBackColor1(state);
                Color c2 = palette.GetRibbonBackColor2(state);

                bool generate = true;
                MementoRibbonGroupCollapsedFrameBorder cache;

                // Access a cache instance and decide if cache resources need generating
                if ((memento == null) || !(memento is MementoRibbonGroupCollapsedFrameBorder))
                {
                    if (memento != null)
                        memento.Dispose();

                    cache = new MementoRibbonGroupCollapsedFrameBorder(rect, c1, c2);
                    memento = cache;
                }
                else
                {
                    cache = (MementoRibbonGroupCollapsedFrameBorder)memento;
                    generate = !cache.UseCachedValues(rect, c1, c2);
                }

                // Do we need to generate the contents of the cache?
                if (generate)
                {
                    // Dispose of existing values
                    cache.Dispose();

                    GraphicsPath solidPath = new GraphicsPath();

                    // Create the rounded complete border
                    solidPath.AddLine(rect.Left + 2, rect.Top, rect.Right - 3, rect.Top);
                    solidPath.AddLine(rect.Right - 3, rect.Top, rect.Right - 1, rect.Top + 2);
                    solidPath.AddLine(rect.Right - 1, rect.Top + 2, rect.Right - 1, rect.Bottom - 3);
                    solidPath.AddLine(rect.Right - 1, rect.Bottom - 3, rect.Right - 3, rect.Bottom - 1);
                    solidPath.AddLine(rect.Right - 3, rect.Bottom - 1, rect.Left + 2, rect.Bottom - 1);
                    solidPath.AddLine(rect.Left + 2, rect.Bottom - 1, rect.Left, rect.Bottom - 3);
                    solidPath.AddLine(rect.Left, rect.Bottom - 3, rect.Left, rect.Top + 2);
                    solidPath.AddLine(rect.Left, rect.Top + 2, rect.Left + 2, rect.Top);

                    cache.solidPath = solidPath;
                    cache.titleBrush = new SolidBrush(c2);
                    cache.solidPen = new Pen(c1);
                }

                // Perform actual drawing using the cache values
                Rectangle titleRect = new Rectangle(rect.Left + 1, rect.Bottom - _groupFrameTitleHeight, rect.Width - 2, _groupFrameTitleHeight - 1);
                context.Graphics.FillRectangle(cache.titleBrush, titleRect);

                using (AntiAlias aa = new AntiAlias(context.Graphics))
                    context.Graphics.DrawPath(cache.solidPen, cache.solidPath);
            }

            return memento;
        }