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pdfcraft/crates/a11y
Grzegorz MartensandClaude Opus 5.5 1b8f3040ee M2.6: accessibility marks no tag whose operator reaches past a stream not read whole
Marking a tag as an artifact, or a figure as decorative, refused content after a stream damaged
partway, placing each operator by its first operand. A page may split its content between an
operator's operands and its keyword. When a `BDC`'s operands end the stream before one damaged
from its start, or one that doesn't decode, the keyword the page reads is in what wasn't read;
joined without it, those operands and the next tag's read as one `BDC`, and marking rewrote the
stream after the hidden one, the next tag's `BDC` taken out of it.

An operator now counts after damage by its keyword, and one whose operands and keyword lie on
either side of a stream not read whole is refused: that stream may end them itself.
`a_tags_operands_before_a_stream_not_read_whole_are_not_rewritten` (damaged from its start, and
not decoding). A tag entirely after a stream that doesn't decode is still marked: such a stream
holds all of its content, between tokens. `accessibility_mark_tag_artifact`'s description names
content a stream that doesn't decode may hide or change too, not only a damaged one.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>
Claude-Session: https://claude.ai/code/session_01AmsdeUCdTaD72jkDw2pJKY
2026-11-07 20:18:07 +01:00
..

pdfcraft-a11y

Layer L4: accessibility (execution plan M12.3). Today: the Accessibility Checker's full check.

let report = check(&doc, &Options::default());          // 31 of 32 rules (colour contrast off)
let html = report_html(&report, "file.pdf", "2026-10-02", "en", &in_english);  // or an interface's words
  • 32 rules in 7 categories, as in Acrobat's full check: Document (permission flag, image-only, tagged, reading order, language, title, bookmarks, colour contrast), Page Content (tagged content, tagged annotations, tab order, character encoding, tagged multimedia, and four manual checks), Forms (tagged fields, descriptions), Alternate Text (figures, nested, associated with content, hides annotation, other elements), Tables (rows, cells, headers, regularity with row/column spans, summary), Lists (items, Lbl/LBody) and Headings (nesting).
  • Each result is Passed, Failed (with findings and pages), Needs manual check, or Skipped.
  • Content checks walk the page content streams (and form XObjects) tracking marked content: painting outside MCID-marked or /Artifact content is untagged.
  • Character encoding accepts a predefined non-Identity CJK CMap or an Adobe CJK character collection (GB1, CNS1, Japan1, Korea1, KR), including Identity-H/V. Unknown CMaps and foreign registries do not establish that route. This is a font-level declaration check, not validation of every ToUnicode entry or used glyph.
  • Structure checks read the structure tree through the role map; table regularity counts ColSpan/RowSpan attributes.
  • The report is a self-contained HTML page. Fixes that edit the document (language, title, tab order) live in the engine (Document::accessibility_fix).

Not yet: autotagging, the Tags/Order/Content panels, the Reading Order tool (M12.1–M12.2).