This class represents the bead dictionary. This is definitively detailed in:.

The ISO PDF Specification, ISO 32000-1:2008 PDF 1.7; Table: 161, page 376.

The ISO PDF Specification, ISO 32000-2:2017 PDF 2.0; Table: 163, page 457.

This class is always an indirect object because BeadElement.EntryN, BeadElement.EntryV, PageObjectElement.EntryB, ThreadActionElement.EntryB and ThreadElement.EntryF require it to be so.

System.Object
    WebSupergoo.ABCpdf14.Elements.Element
       WebSupergoo.ABCpdf14.Elements.BeadElement

A bead dictionary describes one rectangular region on a page forming part of an article thread. Reading the thread in order means following the chain of beads from first to last, each corresponding to a visible passage of content on its host page.

Each bead is an indirect object because it is multiply referenced: by the thread, by its neighbouring beads, and by the page that contains it. The page's B array lists all beads on that page.

The R entry gives the bounding rectangle of the bead in default user space on the referenced page.