Class: Prawn::Font Abstract

Inherits:
Object
  • Object
show all
Defined in:
lib/prawn/font.rb

Overview

This class is abstract.

Provides font information and helper functions.

Direct Known Subclasses

Prawn::Fonts::AFM, Prawn::Fonts::TTF

Experimental API collapse

AFM =
Deprecated. 
Prawn::Fonts::AFM
TTF =
Deprecated. 
Fonts::TTF
DFont =
Deprecated. 
Fonts::DFont
TTC =
Deprecated. 
Fonts::TTC

Experimental API collapse

Experimental API collapse

Instance Attribute Details

#family ⇒ String (readonly)

The font family.

Returns:

  • (String)
Source Code
lib/prawn/font.rb, line 359
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def family

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  @family

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end

#name ⇒ String (readonly)

The font name.

Returns:

  • (String)
Source Code
lib/prawn/font.rb, line 355
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def name

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  @name

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end

#options ⇒ Hash (readonly)

The options hash used to initialize the font.

Returns:

  • (Hash)
Source Code
lib/prawn/font.rb, line 363
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def options

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  @options

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end

Class Method Details

.load(document, src, options = {}) ⇒ Prawn::Fonts::Font

Shortcut interface for constructing a font object. Filenames of the form *.ttf will call TTF.new, *.otf calls OTF.new, *.dfont calls DFont.new, *.ttc goes to TTC.new, and anything else will be passed through to AFM.new.

Parameters:

  • document (Prawn::Document) —

    owning document

  • src (String) —

    font file path

  • options (Hash) (defaults to: {})

Options Hash (options):

  • :family (String)
  • :style (Symbol)

Returns:

  • (Prawn::Fonts::Font)
Source Code
lib/prawn/font.rb, line 377
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def self.load(document, src, options = {})

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  case font_format(src, options)

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  when 'ttf' then TTF.new(document, src, options)

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  when 'otf' then Fonts::OTF.new(document, src, options)

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  when 'dfont' then DFont.new(document, src, options)

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  when 'ttc' then TTC.new(document, src, options)

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  else AFM.new(document, src, options)

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  end

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end

Instance Method Details

#add_to_current_page(subset) ⇒ void

This method returns an undefined value.

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.

Parameters:

  • subset (Integer)
Source Code
lib/prawn/font.rb, line 496
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def add_to_current_page(subset)

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  @references[subset] ||= register(subset)

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  @document.state.page.fonts[identifier_for(subset)] = @references[subset]

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end

#ascender ⇒ Number

The size of the font ascender in PDF points.

Returns:

  • (Number)
Source Code
lib/prawn/font.rb, line 430
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def ascender

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  @ascender / 1000.0 * size

432
end

#descender ⇒ Number

The size of the font descender in PDF points.

Returns:

  • (Number)
Source Code
lib/prawn/font.rb, line 437
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def descender

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  -@descender / 1000.0 * size

439
end

#eql?(other) ⇒ Boolean

Compliments the #hash implementation.

Parameters:

  • other (Object)

Returns:

  • (Boolean)
Source Code
lib/prawn/font.rb, line 532
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def eql?(other)

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  self.class == other.class && name == other.name &&

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    family == other.family && size == other.size

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end

#hash ⇒ Integer

Return a hash (as in Object#hash) for the font. This is required since font objects are used as keys in hashes that cache certain values.

Returns:

  • (Integer)
Source Code
lib/prawn/font.rb, line 524
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def hash

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  [self.class, name, family].hash

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end

#height ⇒ Number

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

Returns:

  • (Number)
Source Code
lib/prawn/font.rb, line 486
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def height

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  height_at(size)

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end

#height_at(size) ⇒ Number

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

Parameters:

  • size (Number)

Returns:

  • (Number)
Source Code
lib/prawn/font.rb, line 478
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def height_at(size)

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  @normalized_height ||= (@ascender - @descender + @line_gap) / 1000.0

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  @normalized_height * size

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end

#inspect ⇒ String

Returns a string containing a human-readable representation of this font.

Returns:

  • (String)
Source Code
lib/prawn/font.rb, line 516
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def inspect

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

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end

#line_gap ⇒ Number

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

Returns:

  • (Number)
Source Code
lib/prawn/font.rb, line 444
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def line_gap

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  @line_gap / 1000.0 * size

446
end

#normalize_encoding(string) ⇒ String

This method is abstract.

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.

Parameters:

  • string (String)

Returns:

  • (String)

Raises:

  • (NotImplementedError)
Source Code
lib/prawn/font.rb, line 456
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def normalize_encoding(_string)

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  raise NotImplementedError,

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    'subclasses of Prawn::Font must implement #normalize_encoding'

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end

#normalize_encoding!(str) ⇒ String

Deprecated.
Note:

This method doesn’t mutate its argument any more.

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

Parameters:

  • str (String)

Returns:

  • (String)
Source Code
lib/prawn/font.rb, line 469
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def normalize_encoding!(str)

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  warn('Font#normalize_encoding! is deprecated. Please use non-mutating version Font#normalize_encoding instead.')

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  str.dup.replace(normalize_encoding(str))

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end