[Raku PDF Project] / [PDF-Tags Module] / PDF::Tags :: ObjRef

class PDF::Tags::ObjRef

Tagged object reference

Synopsis

use PDF::Content::Tag :StructureTags, :IllustrationTags;
use PDF::Tags;
use PDF::Tags::Elem;
use PDF::Tags::ObjRef;

# PDF::Class
use PDF::Class;
use PDF::Page;
use PDF::XObject::Image;

my PDF::Class $pdf .= new;
my PDF::Tags $tags .= create: :$pdf;
# create the document root
my PDF::Tags::Elem $doc = $tags.Document;

my PDF::Page $page = $pdf.add-page;

$page.graphics: -> $gfx {
    my PDF::Tags::Elem $figure = $doc.Figure: :Alt("Example image");
    my PDF::XObject::Image $img .= open: "t/images/lightbulb.gif";
    $figure.do: $gfx, $img, :position[50, 70];
    # verify that we have created an object reference to the image
    my PDF::Tags::ObjRef $ref = $figure.kids[0];
    say $ref.value === $img; # True
}

Description

A PDF::Tags::ObjRef contains a reference to an object of type PDF::Annot (annotation), PDF::Form (Acrobat form), or PDF::XObject (image). These all perform the PDF::Class::StructItem role.

These appear as leaf nodes in a tagged PDF’s usually along-side PDF::Tags::Mark objects to indicate the objects logical positioning in document reading-order.

Note that xobject forms (type PDF::XObject::Form) can be referenced in two different ways:

• as multiple PDF::Tag::Mark references to marked content within the form’s stream.

• as a single PDF::Tag::ObjRef reference

Depending on whether or not the form contains significant sub-structure.

Methods

method value

method value returns PDF::Class::StructItem

The referenced COS object; of type PDF::XObject, PDF::Annot or PDF::Form (PDF::Class::StructItem role).