//// This code is part of Document Solutions for PDF .NET demos.// Copyright (c) MESCIUS inc. All rights reserved.//using System.IO;using System.Drawing;using GrapeCity.Documents.Pdf;using GrapeCity.Documents.Pdf.Structure;using GrapeCity.Documents.Pdf.MarkedContent;using GCTEXT = GrapeCity.Documents.Text;
namespace DsPdfWeb.Demos.Basics{    // This sample shows how to create a PDF/UA-2 (accessible) compliant document.    public class PdfUa2    {        public int CreatePDF(Stream stream)        {            var doc = new GcPdfDocument();
            // PDF/UA-2 is based on PDF 2.0:            doc.PdfVersion = "2.0";            // The document language must be specified for PDF/UA:            doc.Lang = "en";            // Mark the document as PDF/UA-2 conformant:            doc.Metadata.PdfUa = 2;            // PDF/UA-2 requires the "revision" year of the ISO 14289-2:2024 standard itself (not the document's date):            doc.Metadata.PdfUaRev = "2024";            doc.Metadata.Title = "PDF/UA-2 compliant document";            doc.ViewerPreferences.DisplayDocTitle = true;            // Mark the document as conforming to Tagged PDF conventions (required for PDF/UA):            doc.MarkInfo.Marked = true;
            var fnt = GCTEXT.Font.FromFile(Path.Combine("Resources", "Fonts", "NotoSans-Regular.ttf"));
            // PDF/UA-2 requires the structure tree to declare the namespaces it uses.            // Add the standard PDF 2.0 structure namespace:            var ns = new Namespace("http://iso.org/pdf2/ssn");            doc.StructTreeRoot.Namespaces.Add(ns);
            // PDF/UA-2 requires a "Document" structure element as the root of the structure tree,            // associated with the namespace declared above:            var seDocument = new StructElement("Document") { NS = ns };            doc.StructTreeRoot.Children.Add(seDocument);
            const int chapterCount = 3;            for (int i = 0; i < chapterCount; ++i)            {                var page = doc.Pages.Add();                var g = page.Graphics;                float headingTop = 72;
                if (i == 0)                {                    // Structure Destinations are a very new PDF 2.0 mechanism - at the time of writing,                    // neither the DsPdfViewer used in these demos, nor Adobe Acrobat, resolve them yet,                    // so clicking a bookmark below may not navigate to its heading even though the                    // destination itself is generated correctly (per the PDF/UA-2 and PDF 2.0 specs).                    // This note is not part of the document's real content, so it is drawn using the                    // already-embedded font (PDF/UA-2 requires every font used for rendering - including                    // the standard 14 fonts - to be embedded) and marked as a layout artifact rather than                    // tagged content (PDF/UA-2 requires all content to be either tagged or an artifact):                    var tlNote = g.CreateTextLayout();                    tlNote.DefaultFormat.Font = fnt;                    tlNote.DefaultFormat.FontSize = 12;                    tlNote.MarginAll = 72;                    tlNote.MaxWidth = page.Size.Width;                    tlNote.Append(                        "This document's outline (bookmarks) use PDF 2.0 \"Structure Destinations\" to point directly at each " +                        "chapter heading below, as required by PDF/UA-2. Neither the DsPdfViewer used in these demos, nor " +                        "Adobe Acrobat, currently resolve this new destination type, so clicking a bookmark may not navigate " +                        "to the target heading, even though the destination itself is generated correctly.");                    tlNote.PerformLayout(true);
                    var noteRect = tlNote.ContentRectangle;                    noteRect.Inflate(9, 9);
                    g.BeginMarkedContent(new TagArtifact { Type = TagArtifact.Types.TypeLayout });                    g.FillRectangle(noteRect, Color.FromArgb(213, 221, 240));                    g.DrawRectangle(noteRect, Color.FromArgb(59, 92, 170), 0.5f);                    g.DrawTextLayout(tlNote, PointF.Empty);                    g.EndMarkedContent();
                    headingTop = noteRect.Bottom + 24;                }
                // Chapter heading, tagged as a top-level "H1" element under the Document root:                var seHeading = new StructElement("H1") { DefaultPage = page };                seDocument.Children.Add(seHeading);
                var tlHeading = g.CreateTextLayout();                tlHeading.MarginAll = 72;                tlHeading.MarginTop = headingTop;                tlHeading.MaxWidth = page.Size.Width;                tlHeading.DefaultFormat.Font = fnt;                tlHeading.DefaultFormat.FontBold = true;                tlHeading.DefaultFormat.FontSize = 20;                tlHeading.Append($"Chapter {i + 1}");
                g.BeginMarkedContent(new TagMcid("H1", 0));                g.DrawTextLayout(tlHeading, PointF.Empty);                g.EndMarkedContent();                seHeading.ContentItems.Add(new McidContentItemLink(0));
                // Chapter body, tagged as a "P" element under the same Document root:                var seParagraph = new StructElement("P") { DefaultPage = page };                seDocument.Children.Add(seParagraph);
                var tlBody = g.CreateTextLayout();                tlBody.MarginAll = 72;                tlBody.MarginTop = tlHeading.ContentRectangle.Bottom + 24;                tlBody.MaxWidth = page.Size.Width;                tlBody.DefaultFormat.Font = fnt;                tlBody.DefaultFormat.FontSize = 12;                tlBody.Append(Common.Util.LoremIpsum(3, 2, 5));
                g.BeginMarkedContent(new TagMcid("P", 1));                g.DrawTextLayout(tlBody, PointF.Empty);                g.EndMarkedContent();                seParagraph.ContentItems.Add(new McidContentItemLink(1));
                // Add an outline entry for this chapter using a "Structure Destination" - one that points                // at the heading's structure element rather than a page/coordinate pair, as required by                // PDF/UA-2 (see PDF 2.0 spec, 12.3.2.3 "Structure Destinations"):                doc.Outlines.Add(new OutlineNode($"Chapter {i + 1}", new DestinationFitBV(seHeading, null)));            }
            doc.Save(stream);            return doc.Pages.Count;        }    }}