Class: Pdfrb::Document::Pages

Inherits:
Object
  • Object
show all
Includes:
Enumerable
Defined in:
lib/pdfrb/document/pages.rb

Overview

Page-tree facade. Exposes add, [], each, count, delete against the Catalog's /Pages tree.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(document) ⇒ Pages

Returns a new instance of Pages.



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# File 'lib/pdfrb/document/pages.rb', line 12

def initialize(document)
  @document = document
end

Instance Attribute Details

#document ⇒ Object (readonly)

Returns the value of attribute document.



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

def document
  @document
end

Instance Method Details

#[](index) ⇒ Object 



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# File 'lib/pdfrb/document/pages.rb', line 71

def [](index)
  each_with_index { |p, i| return p if i == index }
  nil
end

#add(media_box: [0, 0, 612, 792], rotate: 0) ⇒ Object Also known as: <<

Add a new page at the end of the page tree.

Options:

media_box: [0, 0, 612, 792]   # default US Letter
rotate: 0                     # degrees

Returns the new Model::Type::Page.



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# File 'lib/pdfrb/document/pages.rb', line 23

def add(media_box: [0, 0, 612, 792], rotate: 0)
  root = pages_root
  contents = document.add({}, type: Pdfrb::Model::Cos::Stream)
  page = document.add(
    {
      Type: :Page,
      Parent: Pdfrb::Model::Reference.new(root.oid, root.gen),
      MediaBox: media_box,
      Resources: {},
      Contents: Pdfrb::Model::Reference.new(contents.oid, 0)
    },
    type: Pdfrb::Model::Type::Page
  )
  page.value[:Rotate] = rotate if rotate.nonzero?
  kids = (root.value[:Kids] ||= [])
  kids << Pdfrb::Model::Reference.new(page.oid, page.gen)
  root.value[:Count] = (root.value[:Count] || 0) + 1
  page
end

#count ⇒ Object Also known as: size, length 



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# File 'lib/pdfrb/document/pages.rb', line 51

def count
  raw = pages_root[:Count]
  resolved = raw.is_a?(Pdfrb::Model::Reference) ? document.object(raw)&.value : raw
  case resolved
  when Integer then resolved
  when Numeric then resolved.to_i
  else
    # Fallback: walk the page tree.
    count = 0
    each { count += 1 }
    count
  end
end

#delete(page) ⇒ Object 



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# File 'lib/pdfrb/document/pages.rb', line 76

def delete(page)
  ref = ref_to(page)
  root = pages_root
  kids = root.value[:Kids]
  return unless kids&.delete(ref)

  root.value[:Count] = (root.value[:Count] || 1) - 1
  page
end

#each(&block) ⇒ Object 



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# File 'lib/pdfrb/document/pages.rb', line 44

def each(&block)
  return enum_for(:each) unless block_given?

  walk(pages_root, &block)
  self
end

#empty? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/pdfrb/document/pages.rb', line 67

def empty?
  count.zero?
end