Class: Plugin::Thumbnailer::InputImage

Inherits:
Object
  • Object
show all
Extended by:
Forwardable
Includes:
ClassLogging, MetaData
Defined in:
lib/httpthumbnailer/plugin/thumbnailer.rb

Instance Method Summary collapse

Methods included from MetaData

#mime_type

Constructor Details

#initialize(image, processing_methods, options = {}) ⇒ InputImage

Returns a new instance of InputImage.



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# File 'lib/httpthumbnailer/plugin/thumbnailer.rb', line 90

def initialize(image, processing_methods, options = {})
  @image = image
  @processing_methods = processing_methods
end

Instance Method Details

#equal?(image) ⇒ Boolean

needs to be seen as @image when returned in replace block

Returns:

  • (Boolean) 


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# File 'lib/httpthumbnailer/plugin/thumbnailer.rb', line 151

def equal?(image)
  super image or @image.equal? image
end

#height ⇒ Object 



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# File 'lib/httpthumbnailer/plugin/thumbnailer.rb', line 146

def height
  @image.base_rows
end

#process_image(method, width, height, options) ⇒ Object 



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# File 'lib/httpthumbnailer/plugin/thumbnailer.rb', line 123

def process_image(method, width, height, options)
  @image.replace do |image|
    impl = @processing_methods[method] or raise UnsupportedMethodError, method
    impl.call(image, width, height, options)
  end
end

#thumbnail(spec) ⇒ Object

Raises:



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# File 'lib/httpthumbnailer/plugin/thumbnailer.rb', line 95

def thumbnail(spec)
  spec = spec.dup
  # default backgraud is white
  spec.options['background-color'] = spec.options.fetch('background-color', 'white').sub(/^0x/, '#')

  width = spec.width == :input ? @image.columns : spec.width
  height = spec.height == :input ? @image.rows : spec.height

  raise ZeroSizedImageError.new(width, height) if width == 0 or height == 0

  begin
    process_image(spec.method, width, height, spec.options).replace do |image|
      if image.alpha?
        log.info 'thumbnail has alpha, rendering on background'
        image.render_on_background(spec.options['background-color'])
      end
    end.use do |image|
      Service.stats.incr_total_thumbnails_created
      image_format = spec.format == :input ? @image.format : spec.format

      yield Thumbnail.new(image, image_format, spec.options)
    end
  rescue Magick::ImageMagickError => error
    raise ImageTooLargeError, error.message if error.message =~ /cache resources exhausted/
    raise
  end
end

#use ⇒ Object

behave as @image in processing



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# File 'lib/httpthumbnailer/plugin/thumbnailer.rb', line 131

def use
  @image.use do |image|
    yield self
  end
end

#width ⇒ Object

We use base values since it might have been loaded with size hint and prescaled



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# File 'lib/httpthumbnailer/plugin/thumbnailer.rb', line 142

def width
  @image.base_columns
end