Class: Uniword::Builder::ImageBuilder

Inherits:
Object
  • Object
show all
Defined in:
lib/uniword/builder/image_builder.rb

Overview

Builds images as Drawing elements for embedding in documents.

Supports both inline (flowing with text) and anchor (floating/positioned) images, with proper OOXML Picture chain:

Drawing → Inline/Anchor → Graphic → GraphicData → Picture
  → NonVisualPictureProperties
  → PictureBlipFill → Blip
  → PictureShapeProperties → Transform2D

Examples:

Add an inline image to a paragraph

para << Builder.image('photo.png', width: 500_000, height: 300_000)

Add a floating image

para << Builder.image('logo.png', width: 200_000, height: 200_000,
                      floating: true, align: :right)

Add an image via RunBuilder

run = RunBuilder.new.drawing(ImageBuilder.create_drawing('photo.png'))

Constant Summary collapse

PIC_URI =

Picture namespace URI for GraphicData

"http://schemas.openxmlformats.org/drawingml/2006/picture"

Class Method Summary collapse

Class Method Details

.create_drawing(document, path, width: nil, height: nil, alt_text: nil) ⇒ Wordprocessingml::Drawing

Create an inline Drawing from an image file

Builds the full OOXML Picture chain:

Drawing > Inline > Graphic > GraphicData > Picture
  > nvPicPr > cNvPr + cNvPicPr
  > blipFill > blip(r:embed) + stretch > fillRect
  > spPr > xfrm(off+ext) + prstGeom

Parameters:

  • document (DocumentBuilder, DocumentRoot) —

    Target document

  • path (String) —

    Path to image file

  • width (Integer, nil) (defaults to: nil) —

    Width in EMU (914400 EMU = 1 inch)

  • height (Integer, nil) (defaults to: nil) —

    Height in EMU

  • alt_text (String, nil) (defaults to: nil) —

    Alternative text

Returns:



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# File 'lib/uniword/builder/image_builder.rb', line 126

def self.create_drawing(document, path, width: nil, height: nil,
alt_text: nil)
  r_id = register_image(document, path)

  px_w, px_h = read_dimensions(path)
  w = width || (px_w * 9525) # pixels to EMU
  h = height || (px_h * 9525)

  drawing = Wordprocessingml::Drawing.new

  inline = WpDrawing::Inline.new
  inline.extent = WpDrawing::Extent.new(cx: w, cy: h)
  inline.effect_extent = WpDrawing::EffectExtent.new
  inline.doc_properties = WpDrawing::DocProperties.new(
    id: SecureRandom.random_number(1_000_000_000),
    name: File.basename(path, ".*"),
  )
  inline.graphic = build_graphic(r_id, w, h)

  drawing.inline = inline
  drawing
end

.create_floating(document, path, width: nil, height: nil, alt_text: nil, align: nil, vertical_align: nil, wrap: :square, behind_text: false, pos_x: nil, pos_y: nil) ⇒ Wordprocessingml::Drawing

Create a floating (anchored) Drawing from an image file

Parameters:

  • document (DocumentBuilder, DocumentRoot) —

    Target document

  • path (String) —

    Path to image file

  • width (Integer, nil) (defaults to: nil) —

    Width in EMU

  • height (Integer, nil) (defaults to: nil) —

    Height in EMU

  • alt_text (String, nil) (defaults to: nil) —

    Alternative text

  • align (Symbol, nil) (defaults to: nil) —

    Horizontal alignment (:left, :center, :right)

  • vertical_align (Symbol, nil) (defaults to: nil) —

    Vertical alignment (:top, :middle, :bottom)

  • wrap (Symbol) (defaults to: :square) —

    Text wrapping (:square, :none, :top_and_bottom, default :square)

  • behind_text (Boolean) (defaults to: false) —

    Place image behind text (default false)

  • pos_x (Integer, nil) (defaults to: nil) —

    Horizontal position offset in EMU

  • pos_y (Integer, nil) (defaults to: nil) —

    Vertical position offset in EMU

Returns:



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# File 'lib/uniword/builder/image_builder.rb', line 163

def self.create_floating(document, path, width: nil, height: nil, alt_text: nil,
                         align: nil, vertical_align: nil, wrap: :square,
                         behind_text: false, pos_x: nil, pos_y: nil)
  r_id = register_image(document, path)

  px_w, px_h = read_dimensions(path)
  w = width || (px_w * 9525)
  h = height || (px_h * 9525)

  drawing = Wordprocessingml::Drawing.new

  anchor = WpDrawing::Anchor.new
  anchor.simple_pos = WpDrawing::SimplePos.new(x: 0, y: 0)
  anchor.relative_height = 251_658_240
  anchor.behind_doc = behind_text ? "1" : "0"
  anchor.locked = "0"
  anchor.layout_in_cell = "1"
  anchor.allow_overlap = "1"

  # Horizontal positioning
  anchor.position_h = WpDrawing::PositionH.new(
    relative_from: "margin",
  )
  if align
    anchor.position_h.align = align.to_s
  elsif pos_x
    anchor.position_h.pos_offset = pos_x
  else
    anchor.position_h.align = "left"
  end

  # Vertical positioning
  anchor.position_v = WpDrawing::PositionV.new(
    relative_from: "margin",
  )
  if vertical_align
    anchor.position_v.align = vertical_align.to_s
  elsif pos_y
    anchor.position_v.pos_offset = pos_y
  else
    anchor.position_v.align = "top"
  end

  anchor.extent = WpDrawing::Extent.new(cx: w, cy: h)
  anchor.effect_extent = WpDrawing::EffectExtent.new

  # Text wrapping
  case wrap
  when :none
    anchor.wrap_none = WpDrawing::WrapNone.new
  when :square
    anchor.wrap_square = WpDrawing::WrapSquare.new(wrap_text: "bothSides")
  when :top_and_bottom
    anchor.wrap_top_and_bottom = WpDrawing::WrapTopAndBottom.new
  end

  anchor.doc_properties = WpDrawing::DocProperties.new(
    id: SecureRandom.random_number(1_000_000_000),
    name: File.basename(path, ".*"),
  )
  anchor.graphic = build_graphic(r_id, w, h)

  drawing.anchor = anchor
  drawing
end

.create_floating_run(document, path, width: nil, height: nil, alt_text: nil, align: nil, wrap: :square, behind_text: false) ⇒ Wordprocessingml::Run

Create a Run containing a floating image Drawing

Parameters:

  • document (DocumentBuilder, DocumentRoot) —

    Target document

  • path (String) —

    Path to image file

  • width (Integer, nil) (defaults to: nil) —

    Width in EMU

  • height (Integer, nil) (defaults to: nil) —

    Height in EMU

  • alt_text (String, nil) (defaults to: nil) —

    Alternative text

  • align (Symbol, nil) (defaults to: nil) —

    Horizontal alignment

  • wrap (Symbol) (defaults to: :square) —

    Text wrapping style

  • behind_text (Boolean) (defaults to: false) —

    Place behind text

Returns:



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# File 'lib/uniword/builder/image_builder.rb', line 257

def self.create_floating_run(document, path, width: nil, height: nil,
                             alt_text: nil, align: nil, wrap: :square,
                             behind_text: false)
  run = Wordprocessingml::Run.new
  run.drawings << create_floating(document, path,
                                  width: width, height: height,
                                  alt_text: alt_text, align: align,
                                  wrap: wrap, behind_text: behind_text)
  run
end

.create_run(document, path, width: nil, height: nil, alt_text: nil) ⇒ Wordprocessingml::Run

Create a Run containing an inline image Drawing

Parameters:

  • document (DocumentBuilder, DocumentRoot) —

    Target document

  • path (String) —

    Path to image file

  • width (Integer, nil) (defaults to: nil) —

    Width in EMU

  • height (Integer, nil) (defaults to: nil) —

    Height in EMU

  • alt_text (String, nil) (defaults to: nil) —

    Alternative text

Returns:



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# File 'lib/uniword/builder/image_builder.rb', line 237

def self.create_run(document, path, width: nil, height: nil,
alt_text: nil)
  run = Wordprocessingml::Run.new
  run.drawings << create_drawing(document, path,
                                 width: width, height: height,
                                 alt_text: alt_text)
  run
end

.read_dimensions(path) ⇒ Array(Integer, Integer)

Read image dimensions from file (PNG/JPEG/GIF)

Parameters:

  • path (String) —

    Path to image file

Returns:

  • (Array(Integer, Integer)) —
    width, height

    in pixels



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# File 'lib/uniword/builder/image_builder.rb', line 70

def self.read_dimensions(path)
  data = File.binread(path)[0..64]

  if data&.start_with?("\x89PNG".b)
    # PNG: width at offset 16, height at offset 20 (big-endian uint32)
    w = data[16, 4].unpack1("N")
    h = data[20, 4].unpack1("N")
    [w, h]
  elsif data&.start_with?("\xFF\xD8".b)
    # JPEG: parse SOF marker
    io = StringIO.new(File.binread(path))
    io.read(2) # SOI
    loop do
      marker = io.read(2)
      break unless marker&.start_with?("\xFF".b)

      length = io.read(2)&.unpack1("n")
      break unless length

      payload = io.read(length - 2)
      byte1 = marker.bytes[1]
      # SOF0, SOF2, SOF3 markers contain dimensions
      next unless byte1.between?(0xC0, 0xC3) ||
        byte1 == 0xC5 || byte1 == 0xC6 ||
        byte1 == 0xC7 || byte1.between?(0xC9, 0xCB) ||
        byte1 == 0xCD || byte1 == 0xCE || byte1 == 0xCF

      h = payload[0, 2].unpack1("n")
      w = payload[2, 2].unpack1("n")
      return [w, h]
    end
    [100, 100] # fallback
  else
    [100, 100] # fallback for unknown formats
  end
rescue StandardError => e
  Uniword.logger&.debug do
    "Image dimension detection failed: #{e.message}"
  end
  [100, 100]
end

.register_image(document, path) ⇒ String

Register an image part on the document for DOCX packaging.

Parameters:

  • document (DocumentBuilder, DocumentRoot) —

    Target document

  • path (String) —

    Path to image file

Returns:

  • (String) —

    Relationship ID (e.g., ‘rIdImg1’)



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# File 'lib/uniword/builder/image_builder.rb', line 35

def self.register_image(document, path)
  root = document.respond_to?(:model) ? document.model : document
  if root
    root.image_parts ||= {}
    r_id = "rIdImg#{root.image_parts.size + 1}"
  else
    # No document context — generate a placeholder rId
    r_id = "rIdImg#{SecureRandom.random_number(1_000_000)}"
  end

  content_type = case File.extname(path).downcase
                 when ".png"  then "image/png"
                 when ".jpg", ".jpeg" then "image/jpeg"
                 when ".gif"  then "image/gif"
                 when ".bmp"  then "image/bmp"
                 when ".tiff", ".tif" then "image/tiff"
                 when ".svg" then "image/svg+xml"
                 else "application/octet-stream"
                 end

  if root
    root.image_parts[r_id] = {
      path: path,
      data: File.binread(path),
      content_type: content_type,
      target: "media/#{File.basename(path)}",
    }
  end
  r_id
end