Class: Prawn::Font

Inherits:
Object
  • Object
show all
Defined in:
lib/prawn/font.rb,
lib/prawn/font/afm.rb,
lib/prawn/font/ttf.rb,
lib/prawn/font/dfont.rb

Overview

Provides font information and helper functions.

Direct Known Subclasses

AFM, TTF

Defined Under Namespace

Classes: AFM, DFont, TTF

Instance Attribute Summary collapse

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(document, name, options = {}) ⇒ Font

:nodoc:


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# File 'lib/prawn/font.rb', line 222

def initialize(document,name,options={}) #:nodoc:
  @document   = document
  @name       = name
  @options    = options

  @family     = options[:family]

  @document.proc_set :PDF, :Text
  @identifier = :"F#{@document.font_registry.size + 1}"

  @references = {}
end

Instance Attribute Details

#familyObject (readonly)

The current font family


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# File 'lib/prawn/font.rb', line 208

def family
  @family
end

#nameObject (readonly)

The current font name


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# File 'lib/prawn/font.rb', line 205

def name
  @name
end

#optionsObject (readonly)

The options hash used to initialize the font


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# File 'lib/prawn/font.rb', line 211

def options
  @options
end

Class Method Details

.load(document, name, options = {}) ⇒ Object


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# File 'lib/prawn/font.rb', line 213

def self.load(document,name,options={})
  case name
  when /\.ttf$/   then TTF.new(document, name, options)
  when /\.dfont$/ then DFont.new(document, name, options)
  when /\.afm$/   then AFM.new(document, name, options)
  else                 AFM.new(document, name, options)
  end
end

Instance Method Details

#add_to_current_page(subset) ⇒ Object

Registers the given subset of the current font with the current PDF page. This is safe to call multiple times for a given font and subset, as it will only add the font the first time it is called.


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# File 'lib/prawn/font.rb', line 284

def add_to_current_page(subset)
  @references[subset] ||= register(subset)
  @document.page_fonts.merge!(identifier_for(subset) => @references[subset])
end

#ascenderObject


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# File 'lib/prawn/font.rb', line 235

def ascender
  @ascender / 1000.0 * size
end

#descenderObject


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# File 'lib/prawn/font.rb', line 239

def descender
  @descender / 1000.0 * size
end

#heightObject

Gets height of current font in PDF points at current font size


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# File 'lib/prawn/font.rb', line 276

def height
  height_at(size)
end

#height_at(size) ⇒ Object


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# File 'lib/prawn/font.rb', line 269

def height_at(size)
  @normalized_height ||= (@ascender - @descender + @line_gap) / 1000.0
  @normalized_height * size
end

#identifier_for(subset) ⇒ Object


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# File 'lib/prawn/font.rb', line 247

def identifier_for(subset)
  "#{@identifier}.#{subset}"
end

#inspectObject


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# File 'lib/prawn/font.rb', line 251

def inspect
  "#{self.class.name}< #{name}: #{size} >"
end

#line_gapObject


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# File 'lib/prawn/font.rb', line 243

def line_gap
  @line_gap / 1000.0 * size
end

#normalize_encoding(string) ⇒ Object

Normalizes the encoding of the string to an encoding supported by the font. The string is expected to be UTF-8 going in. It will be re-encoded and the new string will be returned. For an in-place (destructive) version, see normalize_encoding!.

Raises:

  • (NotImplementedError)

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# File 'lib/prawn/font.rb', line 259

def normalize_encoding(string)
  raise NotImplementedError, "subclasses of Prawn::Font must implement #normalize_encoding"
end

#normalize_encoding!(str) ⇒ Object

Destructive version of normalize_encoding; normalizes the encoding of a string in place.


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# File 'lib/prawn/font.rb', line 265

def normalize_encoding!(str)
  str.replace(normalize_encoding(str))
end