Class: ReportBuilder::Image

Inherits:
Object
  • Object
show all
Defined in:
lib/reportbuilder/image.rb

Overview

Abstract class for an image

Direct Known Subclasses

ImageBlob, ImageFilename

Constant Summary collapse

@@n = 
1

Instance Attribute Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(options = Hash.new) ⇒ Image

Returns a new instance of Image.



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# File 'lib/reportbuilder/image.rb', line 18

def initialize(options=Hash.new)
  @id=Digest::MD5.hexdigest(Time.new.to_f.to_s)      
  @type=nil
  if !options.has_key? :name
    @name="Image #{@@n}"
    @@n+=1
  else
    @name=options[:name]
  end
  
  default_options={
    :alt=>@name,
    :chars => [ 'W', 'M', '$', '@', '#', '%', '^', 'x', '*', 'o', '=', '+',
    ':', '~', '.', ' ' ],
    :font_rows => 8,
    :font_cols => 4,
    :width=>400,
    :height=>300
  }
  @options=default_options.merge(options)
  @options.each {|k,v|
    self.send("#{k}=",v) if self.respond_to? k
  }
end

Instance Attribute Details

#alt ⇒ Object

Returns the value of attribute alt.



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# File 'lib/reportbuilder/image.rb', line 7

def alt
  @alt
end

#chars ⇒ Object

Returns the value of attribute chars.



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# File 'lib/reportbuilder/image.rb', line 8

def chars
  @chars
end

#filename ⇒ Object (readonly)

Returns the value of attribute filename.



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# File 'lib/reportbuilder/image.rb', line 14

def filename
  @filename
end

#font_cols ⇒ Object

Returns the value of attribute font_cols.



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# File 'lib/reportbuilder/image.rb', line 10

def font_cols
  @font_cols
end

#font_rows ⇒ Object

Returns the value of attribute font_rows.



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# File 'lib/reportbuilder/image.rb', line 9

def font_rows
  @font_rows
end

#height ⇒ Object

Returns the value of attribute height.



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# File 'lib/reportbuilder/image.rb', line 12

def height
  @height
end

#id ⇒ Object (readonly)

Returns the value of attribute id.



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# File 'lib/reportbuilder/image.rb', line 16

def id
  @id
end

#name ⇒ Object

Returns the value of attribute name.



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# File 'lib/reportbuilder/image.rb', line 6

def name
  @name
end

#type ⇒ Object

Returns the value of attribute type.



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# File 'lib/reportbuilder/image.rb', line 13

def type
  @type
end

#url ⇒ Object (readonly)

Returns the value of attribute url.



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# File 'lib/reportbuilder/image.rb', line 15

def url
  @url
end

#width ⇒ Object

Returns the value of attribute width.



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# File 'lib/reportbuilder/image.rb', line 11

def width
  @width
end

Instance Method Details

#create_file(directory) ⇒ Object 



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# File 'lib/reportbuilder/image.rb', line 112

def create_file(directory)
  raise "Must be implemented" 
end

#generate_raster_from_svg(dir) ⇒ Object

return filename



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# File 'lib/reportbuilder/image.rb', line 120

def generate_raster_from_svg(dir)
  
  out_file="#{dir}/#{@id}.png"
  `rsvg '#{filename}' #{out_file}`
  out_file
end

#generate_tag_html(builder) ⇒ Object

Generate the code for images on html



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# File 'lib/reportbuilder/image.rb', line 99

def generate_tag_html(builder)
  if @type=='svg'
    builder.html("
      <div class='image'>
      <!--[if IE]>
      <embed class='svg' height='#{@options[:height]}' src='#{@url}' width='#{@options[:width]}'></embed>
      <![endif]-->
        <object class='svg' data='#{@url}' height='#{@options[:height]}' type='image/svg+xml' width='#{@options[:width]}'></object>
    </div>")
  else
    builder.html("<img src='#{@url}' alt='#{@options[:alt]}' />")
  end
end

#image_magick ⇒ Object

Get image_magick version of the image



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# File 'lib/reportbuilder/image.rb', line 43

def image_magick
  raise "Must be implemented"
end

#report_building_html(builder) ⇒ Object 



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# File 'lib/reportbuilder/image.rb', line 115

def report_building_html(builder)
  create_file(builder.directory)
  generate_tag_html(builder)
end

#report_building_rtf(builder) ⇒ Object 



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# File 'lib/reportbuilder/image.rb', line 126

def report_building_rtf(builder)
  require 'tmpdir'
  directory=Dir::mktmpdir
  create_file(directory)
  raise "Not implemented on RTF::Document. Use gem install clbustos-rtf for support" unless builder.rtf.respond_to? :image
  if @type=='svg'
    builder.rtf.image(generate_raster_from_svg(directory))
  else
    builder.rtf.image(filename)
  end
end

#report_building_text(builder) ⇒ Object

Based on rubyquiz.com/quiz50.html



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# File 'lib/reportbuilder/image.rb', line 47

def report_building_text(builder)
  if ReportBuilder.has_rmagick?
    # get image_magick version of image
    img = image_magick
    # Resize too-large images. The resulting image is going to be
    # about twice the size of the input, so if the original image is too
    # large we need to make it smaller so the ASCII version won't be too
    # big. The `change_geometry' method computes new dimensions for an
    # image based on the geometry argument. The '320x320>' argument says
    # "If the image is too big to fit in a 320x320 square, compute the
    # dimensions of an image that will fit, but retain the original aspect
    # ratio. If the image is already smaller than 320x320, keep the same
    # dimensions."
    img.change_geometry('320x320>') do |cols, rows|
      img.resize!(cols, rows) if cols != img.columns || rows != img.rows
    end

    # Compute the image size in ASCII "pixels" and resize the image to have
    # those dimensions. The resulting image does not have the same aspect
    # ratio as the original, but since our "pixels" are twice as tall as
    # they are wide we'll get our proportions back (roughly) when we render.
    pr = img.rows / font_rows
    pc = img.columns / font_cols
    img.resize!(pc, pr)

    img = img.quantize(chars.size, Magick::GRAYColorspace)
    img = img.normalize

    out=""
    # Draw the image surrounded by a border. The `view' method is slow but
    # it makes it easy to address individual pixels. In grayscale images,
    # all three RGB channels have the same value so the red channel is as
    # good as any for choosing which character to represent the intensity of
    # this particular pixel.
    border = '+' + ('-' * pc) + '+'
    out += border+"\n"
    img.view(0, 0, pc, pr) do |view|
      pr.times do |i|
        out+= '|'
        pc.times do |j|
          out+= chars[view[i][j].red / (2**16 / chars.size)]
        end
        out+= '|'+"\n"
      end
    end
    out+= border
    builder.preformatted(out)
  else
    raise "Requires RMagick"
  end
end