Class: PDF::Writer::TagAlink

Inherits:
Object
  • Object
show all
Defined in:
lib/pdf/writer.rb

Overview

A callback to support the formation of clickable links to external locations.

Constant Summary collapse

DEFAULT_STYLE =

The default anchored link style.

{
  :color      => Color::RGB::Blue,
  :text_color => Color::RGB::Blue,
  :draw_line  => true,
  :line_style => { :dash => PDF::Writer::StrokeStyle::SOLID_LINE },
  :factor     => 0.05
}

Class Attribute Summary collapse

Class Method Summary collapse

Class Attribute Details

.style ⇒ Object

Sets the style for <c:alink> callback underlines that follow. This is expected to be a hash with the following keys:

:color

The colour to be applied to the link underline. Default is Color::RGB::Blue.

:text_color

The colour to be applied to the link text. Default is Color::RGB::Blue.

:factor

The size of the line, as a multiple of the text height. Default is 0.05.

:draw_line

Whether to draw the underline as part of the link or not. Default is true.

:line_style

The style modification hash supplied to PDF::Writer::StrokeStyle.new. The default is a solid line with normal cap, join, and miter limit values.

Set this to nil to get the default style.



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# File 'lib/pdf/writer.rb', line 2527

def style
  @style
end

Class Method Details

.[](pdf, info) ⇒ Object 



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# File 'lib/pdf/writer.rb', line 2529

def [](pdf, info)
  @style ||= DEFAULT_STYLE.dup

  case info[:status]
  when :start, :start_line
      # The beginning of the link. This should contain the URI for the
      # link as the :params entry, and will also contain the value of
      # :cbid.
    @links ||= {}

    @links[info[:cbid]] = {
      :x         => info[:x],
      :y         => info[:y],
      :angle     => info[:angle],
      :descender => info[:descender],
      :height    => info[:height],
      :uri       => info[:params]["uri"]
    }

    pdf.save_state
    pdf.fill_color @style[:text_color] if @style[:text_color]
    if @style[:draw_line]
      pdf.stroke_color  @style[:color] if @style[:color]
      sz = info[:height] * @style[:factor]
      pdf.stroke_style! StrokeStyle.new(sz, @style[:line_style])
    end
  when :end, :end_line
      # The end of the link. Assume that it is the most recent opening
      # which has closed.
    start = @links[info[:cbid]]
      # Add underlining.
    theta = PDF::Math.deg2rad(start[:angle] - 90.0)
    if @style[:draw_line]
      drop  = start[:height] * @style[:factor] * 1.5
      drop_x = Math.cos(theta) * drop
      drop_y = -Math.sin(theta) * drop
      pdf.move_to(start[:x] - drop_x, start[:y] - drop_y)
      pdf.line_to(info[:x] - drop_x, info[:y] - drop_y).stroke
    end
    pdf.add_link(start[:uri], start[:x], start[:y] +
                 start[:descender], info[:x], start[:y] +
                 start[:descender] + start[:height])
    pdf.restore_state
  end
end