Prawn rotated table cell

Prawn rotated table cell

require 'rubygems'
require 'prawn'

module Prawn
  class Table
    class Cell
      class Text < Cell
        # Returns the width of this text with no wrapping. This will be far off
        # from the final width if the text is long.
        def natural_content_width
          @natural_content_width ||= rotated ?
              with_font do
                b = text_box(:width => spanned_content_height + FPTolerance)
                b.render(:dry_run => true)
                b.height
              end :
              [styled_width_of(@content), @pdf.bounds.width].min
        end

        def rotated
          @text_options[:rotate].to_i % 180 == 90
        end

        # Returns the natural height of this block of text, wrapped to the
        # preset width.
        def natural_content_height
          rotated ? [styled_width_of(@content), @pdf.bounds.height].min :
              with_font do
                b = text_box(:width => spanned_content_width + FPTolerance)
                b.render(:dry_run => true)
                b.height + b.line_gap
              end
        end

        # Draws the text content into its bounding box.
        def draw_content
          with_font do
            @pdf.move_down((@pdf.font.line_gap + @pdf.font.descender)/2)
            with_text_color do
              text_box(:width => rotated ? spanned_content_height : spanned_content_width + FPTolerance,
                       :height => rotated ? spanned_content_width : spanned_content_height + FPTolerance,
                       :at => [2, (rotated ? (spanned_content_height + FPTolerance - natural_content_height) / 2 : @pdf.cursor) ]).render
            end
          end
        end
      end
    end
  end
end

File.open('table.pdf', 'w') do |f|
  Prawn::Document.new do
    table [
        [{content: 'Rotated', rowspan: 4, rotate: 90}, 'Regular'],
        ['Line 1'],
        ['Line 2'],
        ['Line 3'],
    ]
  end.render(f)
end