class Prawn::Font

Provides font information and helper functions.

Attributes

family[R]

The current font family

name[R]

The current font name

options[R]

The options hash used to initialize the font

Public Class Methods

load(document,name,options={}) click to toggle source

Shortcut interface for constructing a font object. Filenames of the form *.ttf will call Font::TTF.new, *.dfont Font::DFont.new, and anything else will be passed through to Font::AFM.new()

# File lib/prawn/font.rb, line 238
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

Public Instance Methods

add_to_current_page(subset) click to toggle source

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.

# File lib/prawn/font.rb, line 310
def add_to_current_page(subset)
  @references[subset] ||= register(subset)
  @document.page.fonts.merge!(identifier_for(subset) => @references[subset])
end
ascender() click to toggle source

The size of the font ascender in PDF points

# File lib/prawn/font.rb, line 261
def ascender
  @ascender / 1000.0 * size
end
descender() click to toggle source

The size of the font descender in PDF points

# File lib/prawn/font.rb, line 267
def descender
  -@descender / 1000.0 * size
end
height() click to toggle source

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

# File lib/prawn/font.rb, line 302
def height
  height_at(size)
end
height_at(size) click to toggle source

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

# File lib/prawn/font.rb, line 295
def height_at(size)
  @normalized_height ||= (@ascender - @descender + @line_gap) / 1000.0
  @normalized_height * size
end
line_gap() click to toggle source

The size of the recommended gap between lines of text in PDF points

# File lib/prawn/font.rb, line 273
def line_gap
  @line_gap / 1000.0 * size
end
normalize_encoding(string) click to toggle source

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!.

# File lib/prawn/font.rb, line 282
def normalize_encoding(string)
  raise NotImplementedError, "subclasses of Prawn::Font must implement #normalize_encoding"
end
normalize_encoding!(str) click to toggle source

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

# File lib/prawn/font.rb, line 289
def normalize_encoding!(str)
  str.replace(normalize_encoding(str))
end

Private Instance Methods

size() click to toggle source
# File lib/prawn/font.rb, line 325
def size
  @document.font_size
end