Class: Prawn::SVG::Elements::TextNode

Inherits:
Object
  • Object
show all
Defined in:
lib/prawn/svg/elements/text_node.rb

Defined Under Namespace

Classes: Chunk

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(component, text, leading_space, trailing_space) ⇒ TextNode

Returns a new instance of TextNode.



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# File 'lib/prawn/svg/elements/text_node.rb', line 8

def initialize(component, text, leading_space, trailing_space)
  @component = component
  @text = text
  @leading_space = leading_space
  @trailing_space = trailing_space
end

Instance Attribute Details

#chunks ⇒ Object (readonly)

Returns the value of attribute chunks.



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# File 'lib/prawn/svg/elements/text_node.rb', line 5

def chunks
  @chunks
end

#component ⇒ Object (readonly)

Returns the value of attribute component.



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# File 'lib/prawn/svg/elements/text_node.rb', line 5

def component
  @component
end

#text ⇒ Object

Returns the value of attribute text.



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# File 'lib/prawn/svg/elements/text_node.rb', line 6

def text
  @text
end

Instance Method Details

#calculate_text_rendering_mode ⇒ Object 



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# File 'lib/prawn/svg/elements/text_node.rb', line 291

def calculate_text_rendering_mode
  return :fill if component.inside_clip_path

  fill = !component.computed_properties.fill.none? # rubocop:disable Style/InverseMethods
  stroke = !component.computed_properties.stroke.none? # rubocop:disable Style/InverseMethods

  if fill && stroke
    :fill_stroke
  elsif fill
    :fill
  elsif stroke
    :stroke
  else
    :invisible
  end
end

#calculated_width ⇒ Object 



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# File 'lib/prawn/svg/elements/text_node.rb', line 23

def calculated_width
  @chunks.reduce(0) do |total, chunk|
    total + (chunk.fixed_width || chunk.base_width) + chunk.offset
  end
end

#combined_kerning_and_letter_spacing ⇒ Object 



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# File 'lib/prawn/svg/elements/text_node.rb', line 280

def combined_kerning_and_letter_spacing
  kerning = component.kerning_pixels
  letter = component.letter_spacing_pixels

  if kerning && letter
    kerning + letter
  else
    kerning || letter
  end
end

#font_for_glyph(prawn, char, primary_font, fallback_fonts) ⇒ Object 



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# File 'lib/prawn/svg/elements/text_node.rb', line 237

def font_for_glyph(prawn, char, primary_font, fallback_fonts)
  return nil if primary_font.glyph_present?(char)

  fallback_fonts.each do |fb|
    prawn.font(fb)
    return fb if prawn.font.glyph_present?(char)
  end

  nil
end

#lay_out(prawn) ⇒ Object 



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# File 'lib/prawn/svg/elements/text_node.rb', line 42

def lay_out(prawn)
  remaining_text = @text
  @chunks = []

  while remaining_text != ''
    x = y = dx = dy = rotate = nil
    remaining = rotation_remaining = false

    comp = component
    while comp
      shifted = comp.x_values.shift
      x ||= shifted
      shifted = comp.y_values.shift
      y ||= shifted
      shifted = comp.dx.shift
      dx ||= shifted
      shifted = comp.dy.shift
      dy ||= shifted

      shifted = comp.rotation.length > 1 ? comp.rotation.shift : comp.rotation.first
      if shifted && rotate.nil?
        rotate = shifted
        remaining ||= comp.rotation != [0]
      end

      remaining ||= comp.x_values.any? || comp.y_values.any? || comp.dx.any? || comp.dy.any? || (rotate && rotate != 0)
      rotation_remaining ||= comp.rotation.length > 1
      comp = comp.parent_component
    end

    rotate = (-rotate if rotate && rotate != 0)

    text_to_draw = remaining ? remaining_text[0..0] : remaining_text

    kerning = component.kerning_enabled?
    opts = { size: component.computed_properties.numeric_font_size, kerning: kerning }

    fallback_fonts = component.fallback_fonts
    font_runs = fallback_fonts&.any? ? split_into_font_runs(prawn, text_to_draw, fallback_fonts) : nil

    kerning_spacing = text_to_draw.length > 1 ? (component.kerning_pixels || 0) * (text_to_draw.length - 1) : 0
    letter_spacing = text_to_draw.length > 1 ? (component.letter_spacing_pixels || 0) * (text_to_draw.length - 1) : 0
    word_spacing = (component.word_spacing_pixels || 0) * text_to_draw.count(' ')
    base_width = width_of_text(prawn, text_to_draw, font_runs, opts) + kerning_spacing + letter_spacing + word_spacing

    offset = dx ? [0, dx].max : 0

    @chunks << Chunk.new(text_to_draw, x, y, dx, dy, rotate, base_width, offset, nil, font_runs)

    if remaining
      remaining_text = remaining_text[1..]
    else
      # we can get to this path with rotations still pending
      # solve this by shifting them out by the number of
      # characters we've just drawn
      shift = remaining_text.length - 1
      if rotation_remaining && shift.positive?
        comp = component
        while comp
          count = [shift, comp.rotation.length - 1].min
          comp.rotation.shift(count) if count.positive?
          comp = comp.parent_component
        end
      end

      break
    end
  end
end

#leading_space? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/prawn/svg/elements/text_node.rb', line 15

def leading_space?
  @leading_space
end

#render(prawn, size, cursor, y_offset) ⇒ Object 



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# File 'lib/prawn/svg/elements/text_node.rb', line 112

def render(prawn, size, cursor, y_offset)
  chunks.each do |chunk|
    cursor.x = chunk.x if chunk.x
    cursor.x += chunk.dx if chunk.dx
    cursor.y = chunk.y if chunk.y
    cursor.y -= chunk.dy if chunk.dy

    width = chunk.fixed_width || chunk.base_width

    unless component.inside_clip_path
      decoration = component.computed_properties.text_decoration
      unless decoration == 'none'
        render_underline(prawn, size, cursor, y_offset, width) if decoration.include?('underline')
        render_overline(prawn, size, cursor, y_offset, width) if decoration.include?('overline')
        render_line_through(prawn, size, cursor, y_offset, width) if decoration.include?('line-through')
      end
      render_link_annotation(prawn, size, cursor, y_offset, width)
    end

    kerning = component.kerning_enabled?
    opts = { size: size, at: [cursor.x, cursor.y + (y_offset || 0)], kerning: kerning }
    opts[:rotate] = chunk.rotate if chunk.rotate

    scaling =
      if chunk.fixed_width && component.current_length_adjust_is_scaling?
        chunk.fixed_width * 100 / chunk.base_width
      else
        100
      end

    spacing_enabled = chunk.fixed_width && !component.current_length_adjust_is_scaling? && chunk.text.length > 1

    # This isn't perfect.  It assumes the parent component which started the textLength context
    # has a character at the end of its text nodes.  If it doesn't, the last character in its
    # children should not take the space.  This is possible but would involve a lot more work so
    # I will park it for now.
    parent_spacing = spacing_enabled && !component.text_length
    spacing =
      if spacing_enabled
        ((chunk.fixed_width - chunk.base_width) / (chunk.text.length - (parent_spacing ? 0 : 1))) + (component.kerning_pixels || 0) + (component.letter_spacing_pixels || 0)
      end

    # Inside clip paths, text renders white in a soft mask to define the
    # clipping region. Override any fill color from the SVG element.
    prawn.fill_color('ffffff') if component.inside_clip_path

    combined_spacing = spacing || combined_kerning_and_letter_spacing
    prawn.horizontal_text_scaling(scaling) do
      prawn.character_spacing(combined_spacing || prawn.character_spacing) do
        prawn.word_spacing(component.word_spacing_pixels || prawn.word_spacing) do
          prawn.text_rendering_mode(calculate_text_rendering_mode) do
            render_text_directly(prawn, chunk.text, chunk.font_runs, opts)
          end
        end
      end
    end

    cursor.x += chunk.fixed_width || chunk.base_width

    # If we're in a textLength context for one of our parents, we'll need to add spacing
    # to the end of our string.  See comment above for why this isn't quite right.
    cursor.x += spacing if parent_spacing
  end
end

#render_line_through(prawn, size, cursor, y_offset, width) ⇒ Object 



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# File 'lib/prawn/svg/elements/text_node.rb', line 260

def render_line_through(prawn, size, cursor, y_offset, width)
  offset, thickness = FontMetrics.strikethrough_metrics(prawn, size)

  prawn.fill_rectangle [cursor.x, cursor.y + (y_offset || 0) + offset + (thickness / 2.0)], width, thickness
end

#render_link_annotation(prawn, size, cursor, y_offset, width) ⇒ Object 



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# File 'lib/prawn/svg/elements/text_node.rb', line 266

def render_link_annotation(prawn, size, cursor, y_offset, width)
  href = component.state.anchor_href
  return unless href

  text_bottom = cursor.y + (y_offset || 0) - scaled_font_size(prawn, :descender, size)
  font_height = scaled_font_size(prawn, :height, size)

  LinkRenderer.new(href, [cursor.x, text_bottom + font_height, cursor.x + width, text_bottom]).render(prawn)
end

#render_overline(prawn, size, cursor, y_offset, width) ⇒ Object 



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# File 'lib/prawn/svg/elements/text_node.rb', line 254

def render_overline(prawn, size, cursor, y_offset, width)
  offset, thickness = FontMetrics.overline_metrics(prawn, size)

  prawn.fill_rectangle [cursor.x, cursor.y + (y_offset || 0) + offset + (thickness / 2.0)], width, thickness
end

#render_text_directly(prawn, text, font_runs, opts) ⇒ Object 



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# File 'lib/prawn/svg/elements/text_node.rb', line 193

def render_text_directly(prawn, text, font_runs, opts)
  if font_runs.nil?
    prawn.draw_text(text, **opts)
  else
    kerning = opts[:kerning]
    x = opts[:at][0]
    font_runs.each do |font_name, run_text|
      run_opts = opts.merge(at: [x, opts[:at][1]])
      if font_name
        prawn.font(font_name) do
          prawn.draw_text(run_text, **run_opts)
          x += prawn.width_of(run_text, size: opts[:size], kerning: kerning)
        end
      else
        prawn.draw_text(run_text, **run_opts)
        x += prawn.width_of(run_text, size: opts[:size], kerning: kerning)
      end
    end
  end
end

#render_underline(prawn, size, cursor, y_offset, width) ⇒ Object 



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# File 'lib/prawn/svg/elements/text_node.rb', line 248

def render_underline(prawn, size, cursor, y_offset, width)
  offset, thickness = FontMetrics.underline_metrics(prawn, size)

  prawn.fill_rectangle [cursor.x, cursor.y + (y_offset || 0) + offset + (thickness / 2.0)], width, thickness
end

#scaled_font_size(prawn, method_name, size) ⇒ Object 



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# File 'lib/prawn/svg/elements/text_node.rb', line 276

def scaled_font_size(prawn, method_name, size)
  (prawn.font.public_send(method_name) / prawn.font_size) * size
end

#split_into_font_runs(prawn, text, fallback_fonts) ⇒ Object 



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# File 'lib/prawn/svg/elements/text_node.rb', line 214

def split_into_font_runs(prawn, text, fallback_fonts)
  primary_font = prawn.font
  runs = []
  current_font = nil
  current_text = +''

  prawn.save_font do
    text.each_char do |char|
      font_for_char = font_for_glyph(prawn, char, primary_font, fallback_fonts)

      if font_for_char != current_font && !current_text.empty?
        runs << [current_font, current_text]
        current_text = +''
      end
      current_font = font_for_char
      current_text << char
    end
  end

  runs << [current_font, current_text] unless current_text.empty?
  runs
end

#total_flexible_and_fixed_width ⇒ Object 



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# File 'lib/prawn/svg/elements/text_node.rb', line 29

def total_flexible_and_fixed_width
  flexible = fixed = 0
  chunks.each do |chunk|
    if chunk.fixed_width.nil?
      flexible += chunk.base_width
      fixed += chunk.offset
    else
      fixed += chunk.offset + chunk.fixed_width
    end
  end
  [flexible, fixed]
end

#trailing_space? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/prawn/svg/elements/text_node.rb', line 19

def trailing_space?
  @trailing_space
end

#width_of_text(prawn, text, font_runs, opts) ⇒ Object 



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# File 'lib/prawn/svg/elements/text_node.rb', line 177

def width_of_text(prawn, text, font_runs, opts)
  if font_runs.nil?
    prawn.width_of(text, **opts)
  else
    font_runs.sum(0.0) do |font_name, run_text|
      if font_name
        width = nil
        prawn.font(font_name) { width = prawn.width_of(run_text, **opts) }
        width
      else
        prawn.width_of(run_text, **opts)
      end
    end
  end
end