class PDF::Reader::ValidatingReceiver

Page#walk will execute the content stream of a page, calling methods on a receiver class provided by the user. Each operator has a specific set of parameters it expects, and we wrap the users receiver class in this one to verify the PDF uses valid parameters.

Without these checks, users can’t be confident about the number of parameters they’ll receive for an operator, or what the type of those parameters will be. Everyone ends up building their own type safety guard clauses and it’s tedious.

Not all operators have type safety implemented yet, but we can expand the number over time.

Public Class Methods

new(wrapped) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 19
def initialize(wrapped)
  @wrapped = wrapped
end

Public Instance Methods

begin_inline_image(*args) click to toggle source

Inline Image Operators

# File lib/pdf/reader/validating_receiver.rb, line 224
def begin_inline_image(*args)
  call_wrapped(:begin_inline_image)
end
begin_inline_image_data(*args) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 228
def begin_inline_image_data(*args)
  # We can't use call_wrapped() here because sorbet won't allow splat args with a dynamic
  # number of elements
  @wrapped.begin_inline_image_data(*args) if @wrapped.respond_to?(:begin_inline_image_data)
end
begin_text_object(*args) click to toggle source

Text Object Operators

# File lib/pdf/reader/validating_receiver.rb, line 59
def begin_text_object(*args)
  call_wrapped(:begin_text_object)
end
concatenate_matrix(*args) click to toggle source

Matrix Operators

# File lib/pdf/reader/validating_receiver.rb, line 42
def concatenate_matrix(*args)
  a, b, c, d, e, f = *args
  call_wrapped(
    :concatenate_matrix,
    TypeCheck.cast_to_numeric!(a),
    TypeCheck.cast_to_numeric!(b),
    TypeCheck.cast_to_numeric!(c),
    TypeCheck.cast_to_numeric!(d),
    TypeCheck.cast_to_numeric!(e),
    TypeCheck.cast_to_numeric!(f),
  )
end
end_inline_image(*args) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 234
def end_inline_image(*args)
  data, _ = *args

  call_wrapped(
    :end_inline_image,
    TypeCheck.cast_to_string!(data)
  )
end
end_text_object(*args) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 63
def end_text_object(*args)
  call_wrapped(:end_text_object)
end
invoke_xobject(*args) click to toggle source

Form XObject Operators

# File lib/pdf/reader/validating_receiver.rb, line 211
def invoke_xobject(*args)
  label, _ = *args

  call_wrapped(
    :invoke_xobject,
    TypeCheck.cast_to_symbol(label)
  )
end
method_missing(methodname, *args) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 251
def method_missing(methodname, *args)
  @wrapped.send(methodname, *args)
end
move_text_position(*args) click to toggle source

Text Positioning Operators

# File lib/pdf/reader/validating_receiver.rb, line 131
def move_text_position(*args) # Td
  x, y, _ = *args
  call_wrapped(
    :move_text_position,
    TypeCheck.cast_to_numeric!(x),
    TypeCheck.cast_to_numeric!(y)
  )
end
move_text_position_and_set_leading(*args) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 140
def move_text_position_and_set_leading(*args) # TD
  x, y, _ = *args
  call_wrapped(
    :move_text_position_and_set_leading,
    TypeCheck.cast_to_numeric!(x),
    TypeCheck.cast_to_numeric!(y)
  )
end
move_to_next_line_and_show_text(*args) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 189
def move_to_next_line_and_show_text(*args) # '
  string, _ = *args
  call_wrapped(
    :move_to_next_line_and_show_text,
    TypeCheck.cast_to_string!(string)
  )
end
move_to_start_of_next_line(*args) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 162
def move_to_start_of_next_line(*args) # T*
  call_wrapped(:move_to_start_of_next_line)
end
page=(page) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 23
def page=(page)
  call_wrapped(:page=, page)
end
respond_to?(meth) click to toggle source

Final safety net for any operators that don’t have type checking enabled yet

# File lib/pdf/reader/validating_receiver.rb, line 247
def respond_to?(meth)
  @wrapped.respond_to?(meth)
end
restore_graphics_state(*args) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 34
def restore_graphics_state(*args)
  call_wrapped(:restore_graphics_state)
end
save_graphics_state(*args) click to toggle source

Graphics State Operators

# File lib/pdf/reader/validating_receiver.rb, line 30
def save_graphics_state(*args)
  call_wrapped(:save_graphics_state)
end
set_character_spacing(*args) click to toggle source

Text State Operators

# File lib/pdf/reader/validating_receiver.rb, line 70
def set_character_spacing(*args)
  char_spacing, _ = *args
  call_wrapped(
    :set_character_spacing,
    TypeCheck.cast_to_numeric!(char_spacing)
  )
end
set_horizontal_text_scaling(*args) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 78
def set_horizontal_text_scaling(*args)
  h_scaling, _ = *args
  call_wrapped(
    :set_horizontal_text_scaling,
    TypeCheck.cast_to_numeric!(h_scaling)
  )
end
set_spacing_next_line_show_text(*args) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 197
def set_spacing_next_line_show_text(*args) # "
  aw, ac, string = *args
  call_wrapped(
    :set_spacing_next_line_show_text,
    TypeCheck.cast_to_numeric!(aw),
    TypeCheck.cast_to_numeric!(ac),
    TypeCheck.cast_to_string!(string)
  )
end
set_text_font_and_size(*args) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 86
def set_text_font_and_size(*args)
  label, size, _ = *args
  call_wrapped(
    :set_text_font_and_size,
    TypeCheck.cast_to_symbol(label),
    TypeCheck.cast_to_numeric!(size)
  )
end
set_text_leading(*args) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 95
def set_text_leading(*args)
  leading, _ = *args
  call_wrapped(
    :set_text_leading,
    TypeCheck.cast_to_numeric!(leading)
  )
end
set_text_matrix_and_text_line_matrix(*args) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 149
def set_text_matrix_and_text_line_matrix(*args) # Tm
  a, b, c, d, e, f = *args
  call_wrapped(
    :set_text_matrix_and_text_line_matrix,
    TypeCheck.cast_to_numeric!(a),
    TypeCheck.cast_to_numeric!(b),
    TypeCheck.cast_to_numeric!(c),
    TypeCheck.cast_to_numeric!(d),
    TypeCheck.cast_to_numeric!(e),
    TypeCheck.cast_to_numeric!(f),
  )
end
set_text_rendering_mode(*args) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 103
def set_text_rendering_mode(*args)
  mode, _ = *args
  call_wrapped(
    :set_text_rendering_mode,
    TypeCheck.cast_to_numeric!(mode)
  )
end
set_text_rise(*args) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 111
def set_text_rise(*args)
  rise, _ = *args
  call_wrapped(
    :set_text_rise,
    TypeCheck.cast_to_numeric!(rise)
  )
end
set_word_spacing(*args) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 119
def set_word_spacing(*args)
  word_spacing, _ = *args
  call_wrapped(
    :set_word_spacing,
    TypeCheck.cast_to_numeric!(word_spacing)
  )
end
show_text(*args) click to toggle source

Text Showing Operators

# File lib/pdf/reader/validating_receiver.rb, line 169
def show_text(*args) # Tj (AWAY)
  string, _ = *args
  call_wrapped(
    :show_text,
    TypeCheck.cast_to_string!(string)
  )
end
show_text_with_positioning(*args) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 177
def show_text_with_positioning(*args) # TJ [(A) 120 (WA) 20 (Y)]
  params, _ = *args
  unless params.is_a?(Array)
    raise MalformedPDFError, "TJ operator expects a single Array argument"
  end

  call_wrapped(
    :show_text_with_positioning,
    params
  )
end

Private Instance Methods

call_wrapped(methodname, *args) click to toggle source
# File lib/pdf/reader/validating_receiver.rb, line 257
def call_wrapped(methodname, *args)
  @wrapped.send(methodname, *args) if @wrapped.respond_to?(methodname)
end