Class: VivlioStarter::Pdf::OutlineWriter

Inherits:
Object
  • Object
show all
Defined in:
lib/vivlio_starter/cli/pdf/outline_writer.rb

Overview

Internal helper responsible for translating outline entries into HexaPDF structures.

Instance Method Summary collapse

Constructor Details

#initialize(doc, max_level:, on_skip: nil) ⇒ OutlineWriter

Returns a new instance of OutlineWriter.

Parameters:

  • doc (HexaPDF::Document) —

    target document

  • max_level (Integer) —

    maximum depth allowed in the outline tree

  • on_skip (Proc, nil) (defaults to: nil) —

    callback triggered when an entry is ignored



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# File 'lib/vivlio_starter/cli/pdf/outline_writer.rb', line 12

def initialize(doc, max_level:, on_skip: nil)
  @doc = doc
  @max_level = max_level.to_i.clamp(1, 6)
  @page_count = @doc.pages.count
  @on_skip = on_skip
end

Instance Method Details

#write(items) ⇒ Integer

Writes the given items into the document outline.

Parameters:

  • items (Array<Hash>) —

    entries with :level, :text, :page

Returns:

  • (Integer) —

    number of inserted outline nodes



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# File 'lib/vivlio_starter/cli/pdf/outline_writer.rb', line 22

def write(items)
  return 0 if @page_count.zero?

  normalized = Array(items).filter_map { normalize_entry(it) }
  return 0 if normalized.empty?

  outline_root = rebuild_outline_root
  stack = [{ level: 0, node: outline_root }]
  inserted = 0

  normalized.each do |entry|
    parent = parent_for(entry[:level], stack)
    destination = resolve_destination(entry[:page])
    unless destination
      warn_skip("page #{entry[:page]} is outside 1-#{@page_count}")
      next
    end

    item = parent.add_item(entry[:text], destination:, open: entry[:level] < @max_level)
    stack << { level: entry[:level], node: item }
    inserted += 1
  end

  if inserted.zero?
    @doc.catalog.delete(:Outlines)
    return 0
  end

  inserted
end