Class: Arrolio::Engine::Paged

Inherits:
Object
  • Object
show all
Defined in:
lib/arrolio/engine/paged.rb

Overview

Two-pass page-flow driver.

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(layout_spec:, flowables:) ⇒ Paged

Returns a new instance of Paged.



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# File 'lib/arrolio/engine/paged.rb', line 9

def initialize(layout_spec:, flowables:)
  @layout_spec = layout_spec
  @flowables = flowables
  @pages = []
end

Instance Attribute Details

#context ⇒ Object (readonly)

Returns the value of attribute context.



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# File 'lib/arrolio/engine/paged.rb', line 7

def context
  @context
end

#flowables ⇒ Object (readonly)

Returns the value of attribute flowables.



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# File 'lib/arrolio/engine/paged.rb', line 7

def flowables
  @flowables
end

#layout_spec ⇒ Object (readonly)

Returns the value of attribute layout_spec.



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# File 'lib/arrolio/engine/paged.rb', line 7

def layout_spec
  @layout_spec
end

#pages ⇒ Object (readonly)

Returns the value of attribute pages.



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# File 'lib/arrolio/engine/paged.rb', line 7

def pages
  @pages
end

Instance Method Details

#layout ⇒ Object 



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# File 'lib/arrolio/engine/paged.rb', line 15

def layout
  @pages = []
  @page_count_opened = 0
  @footnote_page_map = {} # footnote.id / marker -> first page_number
  context = FlowContext.new(layout_spec: @layout_spec, page_number: 1)
  pending = @flowables.dup
  page_state = open_page(context)

  until pending.empty?
    flowable = pending.shift

    if flowable.is_a?(Flowables::PageSequenceStart)
      @current_role = flowable.role
      @current_header = flowable.header_template
      @current_footer = flowable.footer_template
      @current_header_align = flowable.header_align
      @current_footer_align = flowable.footer_align
      unless page_state.fresh && page_state.body_boxes.empty?
        page_state = open_page(context)
      end
      page_state.role = @current_role
      page_state.header = @current_header
      page_state.footer = @current_footer
      page_state.header_align = @current_header_align
      page_state.footer_align = @current_footer_align
      next
    end

    if flowable.is_a?(Flowables::PageBreak)
      page_state = open_page(context)
      next
    end

    # Footnote anchors: record on the current page without
    # consuming frame space (the flowable has zero height).
    if flowable.is_a?(Flowables::FootnoteMarkerFlowable)
      key = flowable.footnote.id || flowable.footnote.marker
      @footnote_page_map[key] ||= page_state.page_number
      page_state.footnotes << flowable.footnote unless page_state.footnotes.include?(flowable.footnote)
      next
    end

    page_state = open_page(context) if flowable.page_break_before? && @pages.any? && !page_state.fresh
    page_state = open_page(context) if page_state.frame.full?

    width = page_state.frame.width
    if flowable.keep_together? &&
       flowable.height(width, context) > page_state.frame.remaining_height &&
       flowable.height(width, context) <= page_state.frame.height
      page_state = open_page(context)
    end

    # Record heading entries for ToC + outline building.
    if flowable.is_a?(Flowables::HeadingFlowable)
      context.record_heading(number: flowable.number,
                             title: flowable.title,
                             level: flowable.level,
                             page_number: page_state.page_number,
                             id: flowable.id)
    end

    page_state.fresh = false
    page_state = place(page_state, flowable, context, pending)
  end

  @context = context
  context.page_count = @pages.length
  finalize_pages
  @pages
end