Class: Prawn::Text::Formatted::Box

Inherits:
Object
  • Object
show all
Defined in:
lib/prawn/text/formatted/box.rb

Overview

Generally, one would use the Prawn::Text::Formatted#formatted_text_box convenience method. However, using Text::Formatted::Box.new in conjunction with #render(:dry_run => true) enables one to do look-ahead calculations prior to placing text on the page, or to determine how much vertical space was consumed by the printed text

Direct Known Subclasses

Box

Experimental API collapse

Experimental API collapse

Extension API collapse

Constructor Details

#initialize(formatted_text, options = {}) ⇒ Box

See Prawn::Text#text_box for valid options



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# File 'lib/prawn/text/formatted/box.rb', line 140

def initialize(formatted_text, options = {})
  @inked = false
  Prawn.verify_options(valid_options, options)
  options = options.dup

  self.class.extensions.reverse_each { |e| extend e }

  @overflow = options[:overflow] || :truncate
  @disable_wrap_by_char = options[:disable_wrap_by_char]

  self.original_text = formatted_text
  @text = nil

  @document = options[:document]
  @direction = options[:direction] || @document.text_direction
  @fallback_fonts = options[:fallback_fonts] ||
    @document.fallback_fonts
  @at = (
    options[:at] || [@document.bounds.left, @document.bounds.top]
  ).dup
  @width = options[:width] ||
    @document.bounds.right - @at[0]
  @height = options[:height] || default_height
  @align = options[:align] ||
    (@direction == :rtl ? :right : :left)
  @vertical_align = options[:valign] || :top
  @leading = options[:leading] || @document.default_leading
  @character_spacing = options[:character_spacing] ||
    @document.character_spacing
  @mode = options[:mode] || @document.text_rendering_mode
  @rotate = options[:rotate] || 0
  @rotate_around = options[:rotate_around] || :upper_left
  @single_line = options[:single_line]
  @draw_text_callback = options[:draw_text_callback]

  # if the text rendering mode is :unknown, force it back to :fill
  if @mode == :unknown
    @mode = :fill
  end

  if @overflow == :expand
    # if set to expand, then we simply set the bottom
    # as the bottom of the document bounds, since that
    # is the maximum we should expand to
    @height = default_height
    @overflow = :truncate
  end
  @min_font_size = options[:min_font_size] || 5
  if options[:kerning].nil?
    options[:kerning] = @document.default_kerning?
  end
  @options = {
    kerning: options[:kerning],
    size: options[:size],
    style: options[:style]
  }

  super(formatted_text, options)
end

Instance Attribute Details

#ascender ⇒ Object (readonly)

The height of the ascender of the last line printed



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# File 'lib/prawn/text/formatted/box.rb', line 128

def ascender
  @ascender
end

#at ⇒ Object (readonly)

The upper left corner of the text box



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# File 'lib/prawn/text/formatted/box.rb', line 124

def at
  @at
end

#descender ⇒ Object (readonly)

The height of the descender of the last line printed



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# File 'lib/prawn/text/formatted/box.rb', line 130

def descender
  @descender
end

#leading ⇒ Object (readonly)

The leading used during printing



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# File 'lib/prawn/text/formatted/box.rb', line 132

def leading
  @leading
end

#line_height ⇒ Object (readonly)

The line height of the last line printed



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# File 'lib/prawn/text/formatted/box.rb', line 126

def line_height
  @line_height
end

#text ⇒ Object (readonly)

The text that was successfully printed (or, if dry_run was used, the text that would have been successfully printed)



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# File 'lib/prawn/text/formatted/box.rb', line 109

def text
  @text
end

Class Method Details

.extensions ⇒ Object

Example (see Prawn::Text::Core::Formatted::Wrap for what is required of the wrap method if you want to override the default wrapping algorithm):

module MyWrap

  def wrap(array)
    initialize_wrap([{ :text => 'all your base are belong to us' }])
    @line_wrap.wrap_line(:document => @document,
                         :kerning => @kerning,
                         :width => 10000,
                         :arranger => @arranger)
    fragment = @arranger.retrieve_fragment
    format_and_draw_fragment(fragment, 0, @line_wrap.width, 0)
    []
  end

end

Prawn::Text::Formatted::Box.extensions << MyWrap

box = Prawn::Text::Formatted::Box.new('hello world')
box.render('why can't I print anything other than' +
           '"all your base are belong to us"?')



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# File 'lib/prawn/text/formatted/box.rb', line 341

def self.extensions
  @extensions ||= []
end

Instance Method Details

#available_width ⇒ Object

The width available at this point in the box



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# File 'lib/prawn/text/formatted/box.rb', line 244

def available_width
  @width
end

#draw_fragment(fragment, accumulated_width = 0, line_width = 0, word_spacing = 0) ⇒ Object

fragment is a Prawn::Text::Formatted::Fragment object



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# File 'lib/prawn/text/formatted/box.rb', line 258

def draw_fragment(
  fragment, accumulated_width = 0, line_width = 0, word_spacing = 0
) #:nodoc:
  case @align
  when :left
    x = @at[0]
  when :center
    x = @at[0] + @width * 0.5 - line_width * 0.5
  when :right
    x = @at[0] + @width - line_width
  when :justify
    x =
      if @direction == :ltr
        @at[0]
      else
        @at[0] + @width - line_width
      end
  else
    raise ArgumentError,
      'align must be one of :left, :right, :center or :justify symbols'
  end

  x += accumulated_width

  y = @at[1] + @baseline_y

  y += fragment.y_offset

  fragment.left = x
  fragment.baseline = y

  if @inked
    draw_fragment_underlays(fragment)

    @document.word_spacing(word_spacing) do
      if @draw_text_callback
        @draw_text_callback.call(
          fragment.text,
          at: [x, y],
          kerning: @kerning
        )
      else
        @document.draw_text!(
          fragment.text,
          at: [x, y],
          kerning: @kerning
        )
      end
    end

    draw_fragment_overlays(fragment)
  end
end

#everything_printed? ⇒ Boolean

True if everything printed (or, if dry_run was used, everything would have been successfully printed)

Returns:

  • (Boolean) 


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# File 'lib/prawn/text/formatted/box.rb', line 119

def everything_printed?
  @everything_printed
end

#height ⇒ Object

The height actually used during the previous render



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# File 'lib/prawn/text/formatted/box.rb', line 250

def height
  return 0 if @baseline_y.nil? || @descender.nil?

  (@baseline_y - @descender).abs
end

#line_gap ⇒ Object 



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# File 'lib/prawn/text/formatted/box.rb', line 134

def line_gap
  line_height - (ascender + descender)
end

#nothing_printed? ⇒ Boolean

True if nothing printed (or, if dry_run was used, nothing would have been successfully printed)

Returns:

  • (Boolean) 


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# File 'lib/prawn/text/formatted/box.rb', line 113

def nothing_printed?
  @nothing_printed
end

#render(flags = {}) ⇒ Object

Render text to the document based on the settings defined in initialize.

In order to facilitate look-ahead calculations, render accepts a :dry_run => true option. If provided, then everything is executed as if rendering, with the exception that nothing is drawn on the page. Useful for look-ahead computations of height, unprinted text, etc.

Returns any text that did not print under the current settings.



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# File 'lib/prawn/text/formatted/box.rb', line 211

def render(flags = {})
  unprinted_text = []

  @document.save_font do
    @document.character_spacing(@character_spacing) do
      @document.text_rendering_mode(@mode) do
        process_options

        text = normalized_text(flags)

        @document.font_size(@font_size) do
          shrink_to_fit(text) if @overflow == :shrink_to_fit
          process_vertical_alignment(text)
          @inked = true unless flags[:dry_run]
          unprinted_text =
            if @rotate != 0 && @inked
              render_rotated(text)
            else
              wrap(text)
            end
          @inked = false
        end
      end
    end
  end

  unprinted_text.map do |e|
    e.merge(text: @document.font.to_utf8(e[:text]))
  end
end

#valid_options ⇒ Object 



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# File 'lib/prawn/text/formatted/box.rb', line 351

def valid_options
  PDF::Core::Text::VALID_OPTIONS + %i[
    at
    height width
    align valign
    rotate rotate_around
    overflow min_font_size
    disable_wrap_by_char
    leading character_spacing
    mode single_line
    document
    direction
    fallback_fonts
    draw_text_callback
  ]
end