Class: PDF::Impose::Builder

Inherits:
Object
  • Object
show all
Defined in:
lib/pdf/impose/builder.rb

Constant Summary collapse

PRIMARY_LAYOUTS = 
{
  'card-fold4' => PDF::Impose::Forms::CardFold::Quarto,
  'card-fold8' => PDF::Impose::Forms::CardFold::Octavo,
  'folio' => PDF::Impose::Forms::Folio,
  'quarto' => PDF::Impose::Forms::Quarto,
  'sexto' => PDF::Impose::Forms::Sexto,
  'octavo' => PDF::Impose::Forms::Octavo,
  'duodecimo' => PDF::Impose::Forms::Duodecimo::OneCutOutside,
  'duodecimo-i' => PDF::Impose::Forms::Duodecimo::OneCutInside,
  'duodecimo-2c' => PDF::Impose::Forms::Duodecimo::TwoCut,
  'sextodecimo' => PDF::Impose::Forms::Sextodecimo::Nested
}.freeze
ALIASES = 
{
  'card-fold4' => %w( card-fold ),
  'card-fold8' => %w( ),
  'folio' => %w( f fo ),
  'quarto' => %w( 4to ),
  'sexto' => %w( 6to 6mo ),
  'octavo' => %w( 8vo octavo ),
  'duodecimo' => %w( twelvemo 12mo ),
  'duodecimo-i' => %w( twelvemo-i 12mo-i ),
  'duodecimo-2c' => %w( twelvemo-2c 12mo-2c ),
  'sextodecimo' => %w( sixteenmo 16mo )
}.freeze
LAYOUTS = 
ALIASES.keys.each_with_object({}) do |key, hash|
  hash[key] = PRIMARY_LAYOUTS[key]
  ALIASES[key].each { |name| hash[name] = hash[key] }
end.freeze

Instance Method Summary collapse

Constructor Details

#initialize(source, options = {}) ⇒ Builder

source: the name of a PDF document to lay out options:

layout: quarto, octavo, etc.
page_size: passed through to Prawn
orientation: passed through to Prawn as :page_layout
forms_per_signature: defaults to layout.per_signature
margin: point size of margin of page (default = 32 points)
start_page: defaults to 1
end_page: defaults to last page of source document
marks: true or false, whether to include registration marks (default true)



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# File 'lib/pdf/impose/builder.rb', line 59

def initialize(source, options={})
  layout_arg = options[:layout]

  @layout = if layout_arg.respond_to?(:recto)
              layout_arg
            else
              LAYOUTS[options[:layout].to_s.downcase]
            end

  raise "`#{options[:layout]}' is not a supported layout" if @layout.nil?

  @margin = options[:margin] || 36 # half inch
  @marks = options.fetch(:marks, true)

  @source = PDF::Reader.new(source)
  @destination = Prawn::Document.new(
    skip_page_creation: true, margin: 0,
    page_size: options[:page_size], page_layout: options[:orientation])

  @start_page = options[:start_page] || 1
  @end_page = [options[:end_page] || 1e6, @source.page_count].min

  @page_count = @end_page - @start_page + 1

  @forms_per_signature = options[:forms_per_signature] ||
                         @layout.per_signature
  @pages_per_signature = @forms_per_signature * @layout.pages_per_form

  @signature_count = (@page_count + @pages_per_signature - 1) /
                     @pages_per_signature

  @signatures = (1..@signature_count).map do |s|
    first = (s - 1) * @pages_per_signature + @start_page
    last = first + @pages_per_signature - 1
    Signature.new(first, last)
  end

  _apply
end

Instance Method Details

#_apply ⇒ Object 



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# File 'lib/pdf/impose/builder.rb', line 103

def _apply
  source_width = @source.page(1).page_object[:MediaBox][2]
  source_height = @source.page(1).page_object[:MediaBox][3]

  height = @destination.margin_box.height

  sheet_width = @destination.margin_box.width - @margin * 2
  sheet_height = height - @margin * 2

  max_cell_width = sheet_width / @layout.columns_per_form
  max_cell_height = sheet_height / @layout.rows_per_form

  width_ratio = max_cell_width.to_f / source_width
  height_ratio = max_cell_height.to_f / source_height
  scale = [width_ratio, height_ratio].min

  cell_width = source_width * scale
  cell_height = source_height * scale

  form_width = cell_width * @layout.columns_per_form
  form_height = cell_height * @layout.rows_per_form

  recto = true
  @layout.layout_signatures(@signatures) do |form|
    left = if recto
             @destination.margin_box.width - @margin - form_width
           else
             @margin
           end

    @destination.start_new_page

    _draw_guides(recto, form_width, form_height) if @marks

    form.each_page do |page|
      x = page.column * cell_width + left
      y = height - (page.row + 1) * cell_height - @margin
      @destination.page.import_page @source, page.number - 1,
                                    x, y, cell_width, cell_height,
                                    page.mirror?
    end

    recto = !recto
  end

  self
end

#_draw_guides(recto, width, height) ⇒ Object 



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# File 'lib/pdf/impose/builder.rb', line 151

def _draw_guides(recto, width, height)
  if recto
    x2 = @destination.margin_box.width - @margin
    x1 = x2 - width
  else
    x1 = @margin
    x2 = x1 + width
  end

  y2 = @destination.margin_box.height - @margin
  y1 = y2 - height

  l1 = x1 - @margin / 2.0
  l2 = l1 + @margin / 4.0
  r1 = x2 + @margin / 4.0
  r2 = x2 + @margin / 2.0

  b1 = y1 - @margin / 2.0
  b2 = y1 - @margin / 4.0
  t1 = y2 + @margin / 4.0
  t2 = y2 + @margin / 2.0

  cx = recto ? (r1 + r2) / 2 : (l1 + l2) / 2
  cy = (t1 + t2) / 2
  radius = (r2 - r1) / 2

  @destination.stroke do
    @destination.line([l1, y1], [l2, y1])
    @destination.line([l1, y2], [l2, y2])
    @destination.line([r1, y1], [r2, y1])
    @destination.line([r1, y2], [r2, y2])

    @destination.line([x1, t1], [x1, t2])
    @destination.line([x2, t1], [x2, t2])
    @destination.line([x1, b1], [x1, b2])
    @destination.line([x2, b1], [x2, b2])

    @destination.circle([cx, cy], radius)
    @destination.line([cx - 1.5 * radius, cy], [cx + 1.5 * radius, cy])
    @destination.line([cx, cy - 1.5 * radius], [cx, cy + 1.5 * radius])
  end

  cut_rows = @layout.cut_row || []
  if cut_rows.any?
    row_height = height.to_f / @layout.rows_per_form

    @destination.stroke do
      cut_rows.each do |row|
        y = y2 - row_height * row
        @destination.line([l1, y], [l2, y])
        @destination.line([r1, y], [r2, y])
      end
    end
  end

  cut_cols = @layout.cut_col || []
  if cut_cols.any?
    col_width = width.to_f / @layout.columns_per_form

    @destination.stroke do
      cut_cols.each do |col|
        x = x1 + col_width * col
        @destination.line([x, t1], [x, t2])
        @destination.line([x, b1], [x, b2])
      end
    end
  end
end

#emit(filename) ⇒ Object 



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# File 'lib/pdf/impose/builder.rb', line 99

def emit(filename)
  @destination.render_file filename
end