Look up a /ViewerPreferences name-typed entry by key

PDFium's structured pdf_doc_viewer_preferences() surfaces the commonly-used entries (print scaling, copies, duplex, page ranges). For other keys whose value is a /Name (e.g. Direction = "L2R"/"R2L", ViewArea = "MediaBox"/"CropBox", or arbitrary author-defined entries), use this by-key lookup. Wraps FPDF_VIEWERREF_GetName.

Usage

pdf_doc_viewer_preference_by_name(doc, key, password = NULL)

Arguments

doc

A pdfium_doc from pdf_doc_open(), or a character path.

key

The viewer-preferences dictionary key as a single non-empty character string (ASCII PDF name, e.g. "Direction").

password

Optional password for encrypted PDFs when doc is a path. Ignored when doc is already an open pdfium_doc.

Value

Character scalar — the entry's name value (without the leading slash), or NA_character_ when the key is absent or the value is not a /Name.

See also

pdf_doc_viewer_preferences().