Class: Pdfrb::Document::Outline

Inherits:
Object
  • Object
show all
Defined in:
lib/pdfrb/document/outline.rb

Overview

Bookmark/outline facade. Builds the /Outlines tree on the Catalog so PDF viewers show a navigation panel.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(document) ⇒ Outline

Returns a new instance of Outline.



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# File 'lib/pdfrb/document/outline.rb', line 10

def initialize(document)
  @document = document
  @entries = []
end

Instance Attribute Details

#document ⇒ Object (readonly)

Returns the value of attribute document.



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# File 'lib/pdfrb/document/outline.rb', line 8

def document
  @document
end

#entries ⇒ Object (readonly)

Returns the value of attribute entries.



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# File 'lib/pdfrb/document/outline.rb', line 8

def entries
  @entries
end

Instance Method Details

#add(title, dest: nil, parent: nil) ⇒ Object 



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# File 'lib/pdfrb/document/outline.rb', line 15

def add(title, dest: nil, parent: nil)
  entry = OutlineEntry.new(title: title.to_s, dest: dest)
  if parent
    parent.add_child(entry)
  else
    @entries << entry
  end
  entry
end

#build! ⇒ Object 



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# File 'lib/pdfrb/document/outline.rb', line 25

def build!
  return if @entries.empty?

  root = @document.add(
    { Type: :Outlines },
    type: Pdfrb::Model::Cos::Dictionary
  )
  root_ref = Pdfrb::Model::Reference.new(root.oid, root.gen)

  prev_dict = nil
  first_ref = nil
  @entries.each do |entry|
    dict = entry.build!(@document)
    ref = Pdfrb::Model::Reference.new(dict.oid, dict.gen)

    dict.value[:Parent] = root_ref
    dict.value[:Prev] = Pdfrb::Model::Reference.new(prev_dict.oid, dict.gen) if prev_dict
    dict.value[:Next] = nil
    prev_dict&.value&.[]=(:Next, ref)

    first_ref ||= ref
    prev_dict = dict
  end

  root.value[:First] = first_ref
  root.value[:Last] = Pdfrb::Model::Reference.new(prev_dict.oid, prev_dict.gen) if prev_dict
  root.value[:Count] = @entries.length

  @document.catalog.value[:Outlines] = root_ref
  root
end