v1.11.0

Added

• Tagging of existing untagged PDFs, in two layers. The happy path, PdfDocument.Tag(text, block => role, options) (and PlanTagging, which returns the plan without applying it), takes the role a caller gives each block of an extraction (PdfBlockRole: headings, paragraphs, list items, tables, continued tables, figures, artifacts) and builds the structure by documented rules: list items grouped into one L with Lbl and LBody, table rows and cells from the lines and their cells with a header row, headers and footers as pagination artifacts, link annotations as Link elements with object references, figures by area, everything else an artifact. Each default is a PdfTagOptions setting, and Customize can change every generated element. The plan API underneath, PdfDocument.CreateTaggingPlan() returns a plan in which a caller (typically an accessibility remediation tool) gives blocks, lines, words, table cells, graphics areas and link annotations of a text extraction a structure role; PdfDocument.ApplyTagging(plan) then writes the marked content, the structure tree, the parent tree, /StructParents, /MarkInfo, the language and the title into the editable document, and marks everything the plan leaves out as an artifact. Pages look and extract the same afterwards: only marked-content operators are added, text-showing operators are split at glyph boundaries without moving a glyph, and Form XObjects are wrapped whole or, when their content belongs to several elements, copied for that use. OnePDF does not choose roles or invent alternate text. Files that already have a structure tree, declare /MarkInfo /Marked true or contain marked content with an /MCID are refused with PdfTaggingException, as are references that come from another document, content referenced twice, impossible nesting and pages that cannot be rewritten safely. A link annotation without /Contents gets the link's alternate text or its words. See docs/tagging.md.

Changed

• CheckPdfUA follows a Form XObject drawn by a Do outside marked content: it reports the form only when it paints something unmarked, and checks the form's own marked content against MCR entries with /Stm in the structure tree and its /StructParents. Before, any such Do was reported as untagged content.