LayoutFarm.Text.EditableTextRun.CustomDrawToThisCanvas C# (CSharp) Method

        public override void CustomDrawToThisCanvas(Canvas canvas, Rectangle updateArea)
        {
            int bWidth = this.Width;
            int bHeight = this.Height;
            if (!this.HasStyle)
            {
                canvas.DrawText(this.mybuffer, new Rectangle(0, 0, bWidth, bHeight), 0);
            }
            else
            {
                TextSpanStyle style = this.SpanStyle;
                switch (EvaluateFontAndTextColor(canvas, style))
                {
                    case DIFF_FONT_SAME_TEXT_COLOR:
                        {
                            var prevFont = canvas.CurrentFont;
                            canvas.CurrentFont = style.FontInfo;
                            canvas.DrawText(this.mybuffer,
                               new Rectangle(0, 0, bWidth, bHeight),
                               style.ContentHAlign);
                            canvas.CurrentFont = prevFont;
                        }
                        break;
                    case DIFF_FONT_DIFF_TEXT_COLOR:
                        {
                            var prevFont = canvas.CurrentFont;
                            var prevColor = canvas.CurrentTextColor;
                            canvas.CurrentFont = style.FontInfo;
                            canvas.CurrentTextColor = style.FontColor;
                            canvas.DrawText(this.mybuffer,
                               new Rectangle(0, 0, bWidth, bHeight),
                               style.ContentHAlign);
                            canvas.CurrentFont = prevFont;
                            canvas.CurrentTextColor = prevColor;
                        }
                        break;
                    case SAME_FONT_DIFF_TEXT_COLOR:
                        {
                            var prevColor = canvas.CurrentTextColor;
                            canvas.DrawText(this.mybuffer,
                            new Rectangle(0, 0, bWidth, bHeight),
                            style.ContentHAlign);
                            canvas.CurrentTextColor = prevColor;
                        }
                        break;
                    default:
                        {
                            canvas.DrawText(this.mybuffer,
                               new Rectangle(0, 0, bWidth, bHeight),
                               style.ContentHAlign);
                        }
                        break;
                }
            }
        }