Class: Flickrcaptionr::Processor

Inherits:
Object
  • Object
show all
Defined in:
lib/flickrcaptionr/processor.rb

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize ⇒ Processor

Returns a new instance of Processor.



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# File 'lib/flickrcaptionr/processor.rb', line 4

def initialize
  Flickrcaptionr::Processor.has_dependencies?
end

Class Method Details

.has_dependencies? ⇒ Boolean

Checks for presence of required tools

Returns:

  • (Boolean) 


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# File 'lib/flickrcaptionr/processor.rb', line 49

def self.has_dependencies?
  unless self.which('convert')
    raise SystemCallError, "ImageMagick is required to use this library.\nYou can install it on Ubuntu/Debian with 'sudo apt-get install imagemagick', or on OSX with 'port install ImageMagick'.\nSpecifically I need 'convert' in my PATH."
  end
  unless self.which('composite')
    raise SystemCallError, "ImageMagick is required to use this library.\nYou can install it on Ubuntu/Debian with 'sudo apt-get install imagemagick', or on OSX with 'port install ImageMagick'.\nSpecifically I need 'composite' in my PATH."
  end
end

Instance Method Details

#add_text!(path, text, opts = {}) ⇒ Object

Add some funky macro text to an image. Takes an optional hash of :font_path, :font_size and :font_stroke (defaults: bundled Coda Heavy font, 36, 2)



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# File 'lib/flickrcaptionr/processor.rb', line 25

def add_text!(path, text, opts={})
  out_filename = File.expand_path(path)
  # Now pull the basename out and add our size string
  out_filename = File.join(File.dirname(out_filename), File.basename(out_filename).gsub(/(.+)\.([A-Za-z0-9]{3,4})$/,'\1-'+Digest::SHA1.hexdigest(text+opts.to_s)+'.\2'))
  # Generate our text layer
  if File.exists?(out_filename)
    puts "Already added text to this image, not doing it again"
  else
    escaped_text = text.gsub('"',"''").gsub(/[^A-Za-z0-9 '\-\.,\?\!]/,"")
    puts "Adding text '#{escaped_text}' to #{path} (original text '#{text}')"

    `convert -background none -fill white -font "#{opts[:font_path] ? opts[:font_path] : (File.join(File.dirname(__FILE__), '..', '..', 'fonts', 'Coda-Heavy.ttf' ))}" -stroke black -strokewidth #{opts[:font_stroke] ? opts[:font_stroke].to_s : 2.to_s} -pointsize #{opts[:font_size] ? opts[:font_size].to_s : 36.to_s} -size #{((Dimensions.width(path)-10).to_s)}  -gravity Center caption:"#{escaped_text}" /tmp/caption-tmp.png`
    if !File.exists?('/tmp/caption-tmp.png')
      raise Flickrcaptionr::TextGenerationFailedException, "Couldn't generate text to overlay! Check your ImageMagick installation and that /tmp is writeable."
    end
    `composite /tmp/caption-tmp.png '#{path}' -compose atop -gravity South '#{out_filename}'`
    if !File.exists?(out_filename)
      raise Flickrcaptionr::CompositionFailedException, "Failed to write output composite file, check your ImageMagick installation and output path setting"
    end
    `rm -rf /tmp/caption-tmp.png`
  end
  return out_filename
end

#resize!(path, width, height) ⇒ Object

Resize an image, fitting the space provided as best as possible with a centre-weighted crop



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# File 'lib/flickrcaptionr/processor.rb', line 8

def resize!(path, width, height)
  out_filename = File.expand_path(path)
  # Now pull the basename out and add our size string
  out_filename = File.join(File.dirname(out_filename), File.basename(out_filename).gsub(/(.+)\.([A-Za-z0-9]{3,4})$/,'\1-'+"#{width.to_i.to_s}x#{height.to_i.to_s}"+'.\2'))
  if File.exists?(out_filename)
    puts "Not resizing, #{out_filename} already exists"
  else
    puts "Resizing #{path} to #{width.to_i.to_s}x#{height.to_i.to_s} at #{out_filename}"
    res = `convert '#{path}' -resize #{width.to_i.to_s}x#{height.to_i.to_s}^ -gravity center -extent #{width.to_i.to_s}x#{height.to_i.to_s} '#{out_filename}'`
    if !File.exists?(out_filename)
      raise Flickrcaptionr::ResizeFailedException, "Failed to write output file, check your ImageMagick installation and output path setting"
    end
  end
  return out_filename
end