class Prawn::Font
Provides font information and helper functions.
Attributes
The current font family
The current font name
The options hash used to initialize the font
Public Class Methods
# File lib/prawn/font.rb, line 297 def self.font_format(src, options) return options.fetch(:format, 'ttf') if src.respond_to? :read case src.to_s when /\.ttf$/i then return 'ttf' when /\.dfont$/i then return 'dfont' else return 'afm' end end
Shortcut interface for constructing a font object. Filenames of the form *.ttf will call Prawn::Font::TTF.new, *.dfont Font::DFont.new, and anything else will be passed through to Font::AFM.new()
# File lib/prawn/font.rb, line 289 def self.load(document, src, options={}) case font_format(src, options) when 'ttf' then TTF.new(document, src, options) when 'dfont' then DFont.new(document, src, options) else AFM.new(document, src, options) end end
Public Instance Methods
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 369 def add_to_current_page(subset) @references[subset] ||= register(subset) @document.state.page.fonts.merge!(identifier_for(subset) => @references[subset]) end
The size of the font ascender in PDF points
# File lib/prawn/font.rb, line 321 def ascender @ascender / 1000.0 * size end
The size of the font descender in PDF points
# File lib/prawn/font.rb, line 327 def descender -@descender / 1000.0 * size end
Gets height of current font in PDF points at current font size
# File lib/prawn/font.rb, line 361 def height height_at(size) end
Gets height of current font in PDF points at the given font size
# File lib/prawn/font.rb, line 354 def height_at(size) @normalized_height ||= (@ascender - @descender + @line_gap) / 1000.0 @normalized_height * size end
The size of the recommended gap between lines of text in PDF points
# File lib/prawn/font.rb, line 333 def line_gap @line_gap / 1000.0 * size end
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 341 def normalize_encoding(string) raise NotImplementedError, "subclasses of Prawn::Font must implement #normalize_encoding" end
Destructive version of #normalize_encoding; normalizes the encoding of a string in place.
# File lib/prawn/font.rb, line 348 def normalize_encoding!(str) str.replace(normalize_encoding(str)) end
Private Instance Methods
generate a font identifier that hasn't been used on the current page yet
# File lib/prawn/font.rb, line 402 def generate_unique_id :"F#{@document.font_registry.size + 1}" end
# File lib/prawn/font.rb, line 406 def size @document.font_size end