class ImgToPdf::FitPageDocument

Public Class Methods

create(page_dimension_pt:, margin_pt:, image:, n_horizontal_pages: 1, n_vertical_pages: 1) click to toggle source

@param [ImgToPdf::Dimension] page_dimension_pt page size. points. @param [ImgToPdf::Margin] margin_pt margin size. points. @param [ImgToPdf::Image] image source image. @param [Integer] n_horizontal_pages number of horizontal pages. @param [Integer] n_vertical_pages number of vertical pages. @return [ImgToPdf::FitPageDocument] document to render PDF.

# File lib/img_to_pdf/fit_page_document.rb, line 12
def self.create(page_dimension_pt:, margin_pt:, image:,
                n_horizontal_pages: 1, n_vertical_pages: 1)
  result = new(page_dimension_pt: page_dimension_pt, margin_pt: margin_pt,
               n_horizontal_pages: n_horizontal_pages,
               n_vertical_pages: n_vertical_pages,
               image: image)
  result.draw
  return result
end
new(page_dimension_pt:, margin_pt:, image:, n_horizontal_pages:, n_vertical_pages:) click to toggle source
# File lib/img_to_pdf/fit_page_document.rb, line 22
def initialize(page_dimension_pt:, margin_pt:, image:,
               n_horizontal_pages:, n_vertical_pages:)
  @page_dimension_pt = page_dimension_pt
  @margin_pt = margin_pt
  @image = image
  @n_horizontal_pages = n_horizontal_pages
  @n_vertical_pages = n_vertical_pages

  @pdf = Prawn::Document.new(
    page_size: @page_dimension_pt.to_a,
    margin: @margin_pt.to_a,
    skip_page_creation: true,
    info: {
      Creator: "img_to_pdf version #{ImgToPdf::VERSION}",
    },
  )
end

Public Instance Methods

draw() click to toggle source
# File lib/img_to_pdf/fit_page_document.rb, line 40
def draw
  canvas_dimension_pt = determine_canvas_dimension_pt
  canvas_scale = determine_canvas_scale(canvas_dimension_pt)
  sub_image_dimension_px = ImgToPdf::Dimension.new(
    width: @image.dimension_px.width / @n_horizontal_pages,
    height: @image.dimension_px.height / @n_vertical_pages,
  )
  each_sub_image(sub_image_dimension_px) do |sub_image|
    @pdf.start_new_page
    @pdf.image(
      sub_image.path,
      scale: canvas_scale,
      at: [0, canvas_dimension_pt.height / @n_vertical_pages],
    )
  end
end
render_file(output_path) click to toggle source

@param [Pathname] output_path path to PDF output.

# File lib/img_to_pdf/fit_page_document.rb, line 58
def render_file(output_path)
  @pdf.render_file(output_path)
end

Private Instance Methods

determine_canvas_dimension_pt() click to toggle source
# File lib/img_to_pdf/fit_page_document.rb, line 64
def determine_canvas_dimension_pt
  w = (@page_dimension_pt.width - @margin_pt.left - @margin_pt.right) *
      @n_horizontal_pages
  h = (@page_dimension_pt.height - @margin_pt.top - @margin_pt.bottom) *
      @n_vertical_pages
  return ImgToPdf::Dimension.new(width: w, height: h)
end
determine_canvas_scale(canvas_dimension_pt) click to toggle source
# File lib/img_to_pdf/fit_page_document.rb, line 72
def determine_canvas_scale(canvas_dimension_pt)
  canvas_dimension_in = canvas_dimension_pt.pt_to_in
  dpi_from_width = @image.dimension_px.width / canvas_dimension_in.width
  dpi_from_height = @image.dimension_px.height / canvas_dimension_in.height
  canvas_dpi = [dpi_from_width, dpi_from_height].max
  return 72 / canvas_dpi
end
each_sub_image(sub_image_dimension_px) { |sub_image| ... } click to toggle source
# File lib/img_to_pdf/fit_page_document.rb, line 80
def each_sub_image(sub_image_dimension_px)
  @n_vertical_pages.times do |i_y|
    @n_horizontal_pages.times do |i_x|
      @image.crop(sub_image_dimension_px.width * i_x,
                  sub_image_dimension_px.height * i_y,
                  sub_image_dimension_px.width,
                  sub_image_dimension_px.height) do |sub_image|
        yield(sub_image)
      end
    end
  end
end