Class: Prawn::Document

Inherits:
Object
  • Object
show all
Includes:
Annotations, Destinations, Internals, PageGeometry, Text, Graphics, Images
Defined in:
lib/prawn/font.rb,
lib/prawn/document.rb,
lib/prawn/document/span.rb,
lib/prawn/document/text.rb,
lib/prawn/document/text/box.rb,
lib/prawn/document/internals.rb,
lib/prawn/document/annotations.rb,
lib/prawn/document/bounding_box.rb,
lib/prawn/document/destinations.rb,
lib/prawn/document/page_geometry.rb,
lib/prawn/document/text/wrapping.rb

Defined Under Namespace

Modules: Annotations, Destinations, Internals, PageGeometry, Text Classes: BoundingBox

Constant Summary

Constants included from Graphics

Graphics::KAPPA

Constants included from Destinations

Destinations::NAME_TREE_CHILDREN_LIMIT

Constants included from PageGeometry

PageGeometry::SIZES

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Methods included from Images

#image

Methods included from Graphics

#circle_at, #curve, #curve_to, #ellipse_at, #fill, #fill_and_stroke, #horizontal_line, #horizontal_rule, #line, #line_to, #line_width, #line_width=, #move_to, #polygon, #rectangle, #stroke, #stroke_bounds, #vertical_line

Methods included from Graphics::Color

#fill_color, hex2rgb, #method_missing, rgb2hex, #stroke_color

Methods included from Destinations

#add_dest, #dest_fit, #dest_fit_bounds, #dest_fit_bounds_horizontally, #dest_fit_bounds_vertically, #dest_fit_horizontally, #dest_fit_rect, #dest_fit_vertically, #dest_xyz, #dests

Methods included from Annotations

#annotate, #link_annotation, #text_annotation

Methods included from Internals

#add_content, #names, #page_fonts, #page_resources, #page_xobjects, #proc_set, #ref

Methods included from PageGeometry

#page_dimensions

Methods included from Text

#text, #text_options

Methods included from Text::Wrapping

#height_of, #naive_wrap

Constructor Details

#initialize(options = {}, &block) ⇒ Document

Creates a new PDF Document. The following options are available:

:page_size

One of the Document::PageGeometry::SIZES [LETTER]

:page_layout

Either :portrait or :landscape

:left_margin

Sets the left margin in points [ 0.5 inch]

:right_margin

Sets the right margin in points [ 0.5 inch]

:top_margin

Sets the top margin in points [ 0.5 inch]

:bottom_margin

Sets the bottom margin in points [0.5 inch]

:skip_page_creation

Creates a document without starting the first page [false]

:compress

Compresses content streams before rendering them [false]

:background

An image path to be used as background on all pages [nil]

Usage:

# New document, US Letter paper, portrait orientation
pdf = Prawn::Document.new                            

# New document, A4 paper, landscaped
pdf = Prawn::Document.new(:page_size => "A4", :page_layout => :landscape)    

# New document, with background
pdf = Prawn::Document.new(:background => "#{Prawn::BASEDIR}/data/images/pigs.jpg")



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# File 'lib/prawn/document.rb', line 85

def initialize(options={},&block)   
  Prawn.verify_options [:page_size, :page_layout, :left_margin, 
    :right_margin, :top_margin, :bottom_margin, :skip_page_creation, 
    :compress, :skip_encoding, :text_options, :background ], options
    
  @objects = []
  @info    = ref(:Creator => "Prawn", :Producer => "Prawn")
  @pages   = ref(:Type => :Pages, :Count => 0, :Kids => [])
  @root    = ref(:Type => :Catalog, :Pages => @pages)
  @page_size       = options[:page_size]   || "LETTER"    
  @page_layout     = options[:page_layout] || :portrait
  @compress        = options[:compress] || false                
  @skip_encoding   = options[:skip_encoding]
  @background      = options[:background]
  @font_size       = 12
  
  text_options.update(options[:text_options] || {}) 
        
  @margins = { :left   => options[:left_margin]   || 36,
               :right  => options[:right_margin]  || 36,  
               :top    => options[:top_margin]    || 36,       
               :bottom => options[:bottom_margin] || 36  }
   
  generate_margin_box
  
  @bounding_box = @margin_box
  
  start_new_page unless options[:skip_page_creation]    
  
  if block
    block.arity < 1 ? instance_eval(&block) : block[self]    
  end 
end

Dynamic Method Handling

This class handles dynamic methods through the method_missing method in the class Prawn::Graphics::Color

Instance Attribute Details

#font_size(points = nil) ⇒ Object

When called with no argument, returns the current font size. When called with a single argument but no block, sets the current font size. When a block is used, the font size is applied transactionally and is rolled back when the block exits. You may still change the font size within a transactional block for individual text segments, or nested calls to font_size.

Prawn::Document.generate("font_size.pdf") do
  font_size 16
  text "At size 16"

  font_size(10) do
    text "At size 10"
    text "At size 6", :size => 6
    text "At size 10"
  end

  text "At size 16"
end

When called without an argument, this method returns the current font size.



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# File 'lib/prawn/font.rb', line 71

def font_size(points=nil)
  return @font_size unless points
  size_before_yield = @font_size
  @font_size = points
  block_given? ? yield : return
  @font_size = size_before_yield
end

#margin_box ⇒ Object

Returns the value of attribute margin_box.



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# File 'lib/prawn/document.rb', line 29

def margin_box
  @margin_box
end

#margins ⇒ Object (readonly)

Returns the value of attribute margins.



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# File 'lib/prawn/document.rb', line 30

def margins
  @margins
end

#page_layout ⇒ Object (readonly)

Returns the value of attribute page_layout.



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# File 'lib/prawn/document.rb', line 30

def page_layout
  @page_layout
end

#page_size ⇒ Object (readonly)

Returns the value of attribute page_size.



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# File 'lib/prawn/document.rb', line 30

def page_size
  @page_size
end

#y ⇒ Object

Returns the value of attribute y.



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# File 'lib/prawn/document.rb', line 29

def y
  @y
end

Class Method Details

.generate(filename, options = {}, &block) ⇒ Object

Creates and renders a PDF document.

When using the implicit block form, Prawn will evaluate the block within an instance of Prawn::Document, simplifying your syntax. However, please note that you will not be able to reference variables from the enclosing scope within this block.

# Using implicit block form and rendering to a file
Prawn::Document.generate "foo.pdf" do
  font "Times-Roman"   
  text "Hello World", :at => [200,720], :size => 32       
end

If you need to access your local and instance variables, use the explicit block form shown below. In this case, Prawn yields an instance of PDF::Document and the block is an ordinary closure: 

# Using explicit block form and rendering to a file   
content = "Hello World"
Prawn::Document.generate "foo.pdf" do |pdf|
  pdf.font "Times-Roman"
  pdf.text content, :at => [200,720], :size => 32
end



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# File 'lib/prawn/document.rb', line 57

def self.generate(filename,options={},&block)
  pdf = new(options,&block)          
  pdf.render_file(filename)
end

Instance Method Details

#bounding_box(*args, &block) ⇒ Object

A bounding box serves two important purposes:

  • Provide bounds for flowing text, starting at a given point

  • Translate the origin (0,0) for graphics primitives, for the purposes

of simplifying coordinate math.

When flowing text, the usage of a bounding box is simple. Text will begin at the point specified, flowing the width of the bounding box. After the block exits, the cursor position will be moved to the bottom of the bounding box (y - height). If flowing text exceeds the height of the bounding box, the text will be continued on the next page, starting again at the top-left corner of the bounding box.

pdf.bounding_box([100,500], :width => 100, :height => 300) do
  pdf.text "This text will flow in a very narrow box starting" +
   "from [100,500]. The pointer will then be moved to [100,200]" +
   "and return to the margin_box"
end

When translating coordinates, the idea is to allow the user to draw relative to the origin, and then translate their drawing to a specified area of the document, rather than adjust all their drawing coordinates to match this new region.

Take for example two triangles which share one point, drawn from the origin:

pdf.polygon [0,250], [0,0], [150,100]
pdf.polygon [100,0], [150,100], [200,0]

It would be easy enough to translate these triangles to another point, e.g [200,200]

pdf.polygon [200,450], [200,200], [350,300]
pdf.polygon [300,200], [350,300], [400,200]

However, each time you want to move the drawing, you’d need to alter every point in the drawing calls, which as you might imagine, can become tedious.

If instead, we think of the drawing as being bounded by a box, we can see that the image is 200 points wide by 250 points tall.

To translate it to a new origin, we simply select a point at (x,y+height)

Using the [200,200] example:

pdf.bounding_box([200,450], :width => 200, :height => 250) do
  pdf.polygon [0,250], [0,0], [150,100]
  pdf.polygon [100,0], [150,100], [200,0]
end

Notice that the drawing is still relative to the origin. If we want to move this drawing around the document, we simply need to recalculate the top-left corner of the rectangular bounding-box, and all of our graphics calls remain unmodified.

By default, bounding boxes are specified relative to the document’s margin_box (which is itself a bounding box). You can also nest bounding boxes, allowing you to build components which are relative to each other

pdf.bouding_box(, :width => 200, :height => 250) do

pdf.bounding_box([50,200], :width => 50, :height => 50) do
  # a 50x50 bounding box that starts 50 pixels left and 50 pixels down 
  # the parent bounding box.
end

end

If you wish to position the bounding boxes at absolute coordinates rather than relative to the margins or other bounding boxes, you can use canvas()

pdf.canvas do
  pdf.bounding_box([200,450], :width => 200, :height => 250) do
    # positioned at 'real' (200,450)
  end
end

Of course, if you use canvas, you will be responsible for ensuring that you remain within the printable area of your document.



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# File 'lib/prawn/document/bounding_box.rb', line 91

def bounding_box(*args, &block)    
  init_bounding_box(block) do |_|
    translate!(args[0])     
    @bounding_box = BoundingBox.new(self, *args)   
  end
end

#bounds ⇒ Object

Returns the current BoundingBox object, which is by default the box represented by the margin box. When called from within a bounding_box block, the box defined by that call will be used.



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# File 'lib/prawn/document.rb', line 197

def bounds
  @bounding_box
end

#bounds=(bounding_box) ⇒ Object

Sets Document#bounds to the BoundingBox provided. If you don’t know why you’d need to do this, chances are, you can ignore this feature



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# File 'lib/prawn/document.rb', line 204

def bounds=(bounding_box)
  @bounding_box = bounding_box
end

#canvas(&block) ⇒ Object

A shortcut to produce a bounding box which is mapped to the document’s absolute coordinates, regardless of how things are nested or margin sizes.

pdf.canvas do
  pdf.line pdf.bounds.bottom_left, pdf.bounds.top_right
end



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# File 'lib/prawn/document/bounding_box.rb', line 105

def canvas(&block)     
  init_bounding_box(block, :hold_position => true) do |_|
    @bounding_box = BoundingBox.new(self, [0,page_dimensions[3]], 
      :width => page_dimensions[2], 
      :height => page_dimensions[3] 
    ) 
  end
end

#compression_enabled? ⇒ Boolean

Returns true if content streams will be compressed before rendering, false otherwise

Returns:

  • (Boolean) 


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# File 'lib/prawn/document.rb', line 274

def compression_enabled?
  !!@compress
end

#cursor ⇒ Object

The current y drawing position relative to the innermost bounding box, or to the page margins at the top level.



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# File 'lib/prawn/document.rb', line 164

def cursor
  y - bounds.absolute_bottom
end

#find_font(name, options = {}) ⇒ Object

Looks up the given font using the given criteria. Once a font has been found by that matches the criteria, it will be cached to subsequent lookups for that font will return the same object. – Challenges involved: the name alone is not sufficient to uniquely identify a font (think dfont suitcases that can hold multiple different fonts in a single file). Thus, the :name key is included in the cache key.

It is further complicated, however, since fonts in some formats (like the dfont suitcases) can be identified either by numeric index, OR by their name within the suitcase, and both should hash to the same font object (to avoid the font being embedded multiple times). This is not yet implemented, which means if someone selects a font both by name, and by index, the font will be embedded twice. Since we do font subsetting, this double embedding won’t be catastrophic, just annoying. ++



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# File 'lib/prawn/font.rb', line 115

def find_font(name, options={}) #:nodoc:
  if font_families.key?(name)
    family, name = name, font_families[name][options[:style] || :normal]

    if name.is_a?(Hash)
      options = options.merge(name)
      name = options[:file]
    end
  end

  key = "#{name}:#{options[:font] || 0}"
  font_registry[key] ||= Font.load(self, name, options.merge(:family => family))
end

#font(name = nil, options = {}) ⇒ Object

Without arguments, this returns the currently selected font. Otherwise, it sets the current font.

The single parameter must be a string. It can be one of the 14 built-in fonts supported by PDF, or the location of a TTF file. The Font::AFM::BUILT_INS array specifies the valid built in font values.

pdf.font "Times-Roman"
pdf.font "Chalkboard.ttf"

If a ttf font is specified, the glyphs necessary to render your document will be embedded in the rendered PDF. This should be your preferred option in most cases. It will increase the size of the resulting file, but also make it more portable.

Raises:



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# File 'lib/prawn/font.rb', line 30

def font(name=nil, options={})
  return @font || font("Helvetica") if name.nil?

  raise Errors::NotOnPage unless @current_page
  new_font = find_font(name, options)

  if block_given?
    save_font do
      set_font(new_font, options[:size])
      yield
    end
  else
    set_font(new_font, options[:size])
  end

  @font
end

#font_families ⇒ Object

Hash that maps font family names to their styled individual font names

To add support for another font family, append to this hash, e.g:

pdf.font_families.update(
 "MyTrueTypeFamily" => { :bold        => "foo-bold.ttf",
                         :italic      => "foo-italic.ttf",
                         :bold_italic => "foo-bold-italic.ttf",
                         :normal      => "foo.ttf" })

This will then allow you to use the fonts like so:

pdf.font("MyTrueTypeFamily", :style => :bold)
pdf.text "Some bold text"
pdf.font("MyTrueTypeFamily")
pdf.text "Some normal text"

This assumes that you have appropriate TTF fonts for each style you wish to support.



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# File 'lib/prawn/font.rb', line 155

def font_families
  @font_families ||= Hash.new { |h,k| h[k] = {} }.merge!(
    { "Courier"     => { :bold        => "Courier-Bold",
                         :italic      => "Courier-Oblique",
                         :bold_italic => "Courier-BoldOblique",
                         :normal      => "Courier" },

      "Times-Roman" => { :bold         => "Times-Bold",
                         :italic       => "Times-Italic",
                         :bold_italic  => "Times-BoldItalic",
                         :normal       => "Times-Roman" },

      "Helvetica"   => { :bold         => "Helvetica-Bold",
                         :italic       => "Helvetica-Oblique",
                         :bold_italic  => "Helvetica-BoldOblique",
                         :normal       => "Helvetica" }
    })
end

#font_registry ⇒ Object

Hash of Font objects keyed by names



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# File 'lib/prawn/font.rb', line 131

def font_registry #:nodoc:
  @font_registry ||= {}
end

#mask(*fields) ⇒ Object

:nodoc:



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# File 'lib/prawn/document.rb', line 261

def mask(*fields) # :nodoc:
 # Stores the current state of the named attributes, executes the block, and
 # then restores the original values after the block has executed.
 # -- I will remove the nodoc if/when this feature is a little less hacky
  stored = {}
  fields.each { |f| stored[f] = send(f) }
  yield
  fields.each { |f| send("#{f}=", stored[f]) }
end

#move_down(n) ⇒ Object

Moves down the document by n point



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# File 'lib/prawn/document.rb', line 216

def move_down(n)
  self.y -= n
end

#move_up(n) ⇒ Object

Moves up the document by n points



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# File 'lib/prawn/document.rb', line 210

def move_up(n)
  self.y += n
end

#pad(y) ⇒ Object

Moves down the document by y, executes a block, then moves down the document by y again.

pdf.text "some text"
pdf.pad(100) do
  pdf.text "This is 100 points below the previous line of text"  
end
pdf.text "This is 100 points below the previous line of text"



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# File 'lib/prawn/document.rb', line 255

def pad(y)
  move_down(y)
  yield
  move_down(y)
end

#pad_bottom(y) ⇒ Object

Executes a block then moves down the document

pdf.text "some text"
pdf.pad_bottom(100) do
  pdf.text "This text appears right below the previous line of text"
end
pdf.text "This is 100 points below the previous line of text"



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# File 'lib/prawn/document.rb', line 241

def pad_bottom(y)
  yield
  move_down(y)
end

#pad_top(y) ⇒ Object

Moves down the document and then executes a block.

pdf.text "some text"
pdf.pad_top(100) do
  pdf.text "This is 100 points below the previous line of text"
end
pdf.text "This text appears right below the previous line of text"



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# File 'lib/prawn/document.rb', line 228

def pad_top(y)
  move_down(y)
  yield
end

#page_count ⇒ Object

Returns the number of pages in the document

pdf = Prawn::Document.new
pdf.page_count #=> 1
3.times { pdf.start_new_page }
pdf.page_count #=> 4



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# File 'lib/prawn/document.rb', line 157

def page_count
  @pages.data[:Count]
end

#render ⇒ Object

Renders the PDF document to string



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# File 'lib/prawn/document.rb', line 170

def render
  output = StringIO.new
  finish_page_content

  render_header(output)
  render_body(output)
  render_xref(output)
  render_trailer(output)
  str = output.string 
  str.force_encoding("ASCII-8BIT") if str.respond_to?(:force_encoding)
  str
end

#render_file(filename) ⇒ Object

Renders the PDF document to file.

pdf.render_file "foo.pdf"



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# File 'lib/prawn/document.rb', line 187

def render_file(filename)
  Kernel.const_defined?("Encoding") ? mode = "wb:ASCII-8BIT" : mode = "wb"
  File.open(filename,mode) { |f| f << render }
end

#save_font ⇒ Object

Saves the current font, and then yields. When the block finishes, the original font is restored.



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# File 'lib/prawn/font.rb', line 88

def save_font
  @font ||= find_font("Helvetica")
  original_font = @font
  original_size = @font_size

  yield
ensure
  set_font(original_font, original_size) if original_font
end

#set_font(font, size = nil) ⇒ Object

Sets the font directly, given an actual Font object and size.



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# File 'lib/prawn/font.rb', line 81

def set_font(font, size=nil) # :nodoc:
  @font = font
  @font_size = size if size
end

#span(width, options = {}) ⇒ Object

A span is a special purpose bounding box that allows a column of elements to be positioned relative to the margin_box.

Arguments:

width

The width of the column in PDF points

Options:

:position

One of :left, :center, :right or an x offset

This method is typically used for flowing a column of text from one page to the next.

span(350, :position => :center) do
  text "Here's some centered text in a 350 point column. " * 100
end



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# File 'lib/prawn/document/span.rb', line 27

def span(width, options={})
  Prawn.verify_options [:position], options
  original_position = self.y      
  
  # FIXME: How many effing times do I want to write this same code?
  left_boundary = case(options[:position] || :left)
  when :left
    margin_box.absolute_left
  when :center
    margin_box.absolute_left + margin_box.width / 2.0 - width /2.0
  when :right
    margin_box.absolute_right - width
  when Numeric
    margin_box.absolute_left + options[:position]
  else
    raise ArgumentError, "Invalid option for :position"
  end
  
  # we need to bust out of whatever nested bounding boxes we're in.
  canvas do
    bounding_box([left_boundary, 
                  margin_box.absolute_top], :width => width) do
      self.y = original_position
      yield
    end
  end          
end

#start_new_page(options = {}) ⇒ Object

Creates and advances to a new page in the document.

Page size, margins, and layout can also be set when generating a new page. These values will become the new defaults for page creation

pdf.start_new_page(:size => "LEGAL", :layout => :landscape)    
pdf.start_new_page(:left_margin => 50, :right_margin => 50)



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# File 'lib/prawn/document.rb', line 127

def start_new_page(options = {})      
   @page_size   = options[:size] if options[:size]
   @page_layout = options[:layout] if options[:layout]
                                         
   [:left,:right,:top,:bottom].each do |side|  
     if options[:"#{side}_margin"] 
       @margins[side] = options[:"#{side}_margin"]   
     end
   end
   
   finish_page_content if @page_content  
   build_new_page_content

   @pages.data[:Kids] << @current_page
   @pages.data[:Count] += 1 
 
   add_content "q"   
   
   @y = @bounding_box.absolute_top
   
   image(@background, :at => [0,@y]) if @background
end

#text_box(text, options) ⇒ Object

Defines an invisible rectangle which you can flow text in. When the text overflows the box, you can either display :ellipses, :truncate the text, or allow it to :overflow the bottom boundary.

text_box "Oh hai text box. " * 200, 
  :width    => 300, :height => font.height * 5,
  :overflow => :ellipses, 
  :at       => [100,bounds.top]



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# File 'lib/prawn/document/text/box.rb', line 21

def text_box(text,options)
  Text::Box.new(text, options.merge(:for => self)).render
end

#width_of(string, options = {}) ⇒ Object

Returns the width of the given string using the given font. If :size is not specified as one of the options, the string is measured using the current font size. You can also pass :kerning as an option to indicate whether kerning should be used when measuring the width (defaults to false).

Note that the string must be encoded properly for the font being used. For AFM fonts, this is WinAnsi. For TTF, make sure the font is encoded as UTF-8. You can use the Font#normalize_encoding method to make sure strings are in an encoding appropriate for the current font. – For the record, this method used to be a method of Font (and still delegates to width computations on Font). However, having the primary interface for calculating string widths exist on Font made it tricky to write extensions for Prawn in which widths are computed differently (e.g., taking formatting tags into account, or the like).

By putting width_of here, on Document itself, extensions may easily override it and redefine the width calculation behavior. ++



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# File 'lib/prawn/font.rb', line 193

def width_of(string, options={})
  font.compute_width_of(string, options)
end