Class: CorpPdf::Fields::Signature

Inherits:
Object
  • Object
show all
Includes:
Base
Defined in:
lib/corp_pdf/fields/signature.rb

Overview

Handles signature field creation

Instance Attribute Summary collapse

Attributes included from Base

#document, #field_type, #field_value, #metadata, #name, #options

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Base

#height, #initialize, #page_num, #width, #x, #y

Methods included from Actions::Base

#acroform_ref, #apply_patch, #find_page_by_number, #get_object_body_with_patch, #next_fresh_object_number, #patches, #resolver

Instance Attribute Details

#field_obj_num ⇒ Object (readonly)

Returns the value of attribute field_obj_num.



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# File 'lib/corp_pdf/fields/signature.rb', line 11

def field_obj_num
  @field_obj_num
end

Class Method Details

.add_appearance(document, field_ref, image_data, width: nil, height: nil) ⇒ Object

Class method to add appearance to an existing signature field Can be called from both Signature field creation and UpdateField



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# File 'lib/corp_pdf/fields/signature.rb', line 15

def self.add_appearance(document, field_ref, image_data, width: nil, height: nil)
  new(document, "", {}).add_appearance_to_field(field_ref, image_data, width: width, height: height)
end

Instance Method Details

#add_appearance_to_field(field_ref, image_data, width: nil, height: nil) ⇒ Object 



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# File 'lib/corp_pdf/fields/signature.rb', line 47

def add_appearance_to_field(field_ref, image_data, width: nil, height: nil)
  return false unless field_ref && image_data && !image_data.empty?

  # Decode image data if needed
  decoded_image_data = image_data.is_a?(String) && image_data.start_with?("data:") ? decode_base64_data_uri(image_data) : decode_base64_if_needed(image_data)
  return false unless decoded_image_data && !decoded_image_data.empty?

  # Detect image format and dimensions
  image_info = detect_image_format(decoded_image_data)
  return false unless image_info

  # Find widget annotation for this field
  widget_ref = find_signature_widget(field_ref)
  return false unless widget_ref

  widget_body = get_object_body_with_patch(widget_ref)
  return false unless widget_body

  # Get widget rectangle for appearance size
  rect = extract_rect(widget_body)
  return false unless rect

  # Ensure width and height are positive
  rect_width = (rect[:x2] - rect[:x1]).abs
  rect_height = (rect[:y2] - rect[:y1]).abs
  return false if rect_width <= 0 || rect_height <= 0

  # Get field dimensions (use provided width/height or field rect)
  field_width = width || rect_width
  field_height = height || rect_height

  # Get image natural dimensions
  image_width = image_info[:width].to_f
  image_height = image_info[:height].to_f
  return false if image_width <= 0 || image_height <= 0

  # Calculate scaling factor to fit image within field while maintaining aspect ratio
  scale_x = field_width / image_width
  scale_y = field_height / image_height
  scale_factor = [scale_x, scale_y].min

  # Calculate scaled dimensions (maintains aspect ratio, fits within field)
  scaled_width = image_width * scale_factor
  scaled_height = image_height * scale_factor

  # Create Image XObject(s) - use natural image dimensions (not scaled)
  image_obj_num = next_fresh_object_number
  image_result = create_image_xobject(image_obj_num, decoded_image_data, image_info, image_width, image_height)
  image_body = image_result[:body]
  mask_obj_num = image_result[:mask_obj_num]

  # Create Form XObject (appearance stream) - use field dimensions for bounding box
  form_obj_num = mask_obj_num ? mask_obj_num + 1 : image_obj_num + 1
  form_body = create_form_xobject(form_obj_num, image_obj_num, field_width, field_height, scale_factor,
                                  scaled_width, scaled_height)

  # Queue new objects
  document.instance_variable_get(:@patches) << { ref: [image_obj_num, 0], body: image_body }
  if mask_obj_num
    document.instance_variable_get(:@patches) << { ref: [mask_obj_num, 0],
                                                   body: image_result[:mask_body] }
  end
  document.instance_variable_get(:@patches) << { ref: [form_obj_num, 0], body: form_body }

  # Update widget annotation with /AP dictionary
  # Use already-loaded widget_body as original (we already have it from line 62)
  # Only reload if we don't have it (shouldn't happen, but for safety)
  original_widget_body = widget_body || resolver.object_body(widget_ref)
  updated_widget = add_appearance_to_widget(widget_body, form_obj_num)
  apply_patch(widget_ref, updated_widget, original_widget_body)

  true
end

#call ⇒ Object 



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# File 'lib/corp_pdf/fields/signature.rb', line 19

def call
  @field_obj_num = next_fresh_object_number
  widget_obj_num = @field_obj_num + 1

  field_body = create_field_dictionary(@field_value, @field_type)
  page_ref = find_page_ref(page_num)

  widget_body = create_widget_annotation_with_parent(widget_obj_num, [@field_obj_num, 0], page_ref, x, y, width,
                                                     height, @field_type, @field_value)

  document.instance_variable_get(:@patches) << { ref: [@field_obj_num, 0], body: field_body }
  document.instance_variable_get(:@patches) << { ref: [widget_obj_num, 0], body: widget_body }

  add_field_to_acroform_with_defaults(@field_obj_num)
  add_widget_to_page(widget_obj_num, page_num)

  # If this is a signature field with image data, add the signature appearance
  if @field_value && !@field_value.empty?
    image_data = @field_value
    if image_data.is_a?(String) && (image_data.start_with?("data:image/") || (image_data.length > 50 && image_data.match?(%r{^[A-Za-z0-9+/]*={0,2}$})))
      field_ref = [@field_obj_num, 0]
      add_appearance_to_field(field_ref, image_data, width: width, height: height)
    end
  end

  true
end