Class: Zena::Use::ImageBuilder

Inherits:
Object
  • Object
show all
Defined in:
lib/zena/use/image_builder.rb

Constant Summary collapse

DEFAULT_FORMATS = 
{
  'tiny'  => { :name=>'tiny', :size=>:force, :width=>16,  :height=>16 , :gravity=>Magick::CenterGravity   },
  'tipop' => { :name=>'tipop', :size=>:force, :width=>16,  :height=>16 , :gravity=>Magick::CenterGravity,
    :popup => {
        :name    => 'std',
        :options => {'title' => 'link'},
        :show    => ['navigation','title','summary']
      }
  },
  'mini' =>   { :name=>'mini', :size=>:force, :width=>32,  :height=>32 , :gravity=>Magick::CenterGravity   },
  'square' => { :name=>'square', :size=>:limit, :width=>180, :height=>180, :gravity=>Magick::CenterGravity },
  'med'  =>   { :name=>'med',  :size=>:limit, :width=>280, :height=>186, :gravity=>Magick::CenterGravity   },
  'top'  =>   { :name=>'top',  :size=>:force, :width=>280, :height=>186, :gravity => Magick::NorthGravity  },
  'low'  =>   { :name=>'low',  :size=>:force, :width=>280, :height=>186, :gravity => Magick::SouthGravity  },
  'side' =>   { :name=>'side', :size=>:force, :width=>220, :height=>500, :gravity=>Magick::CenterGravity   },
  'std'  =>   { :name=>'std',  :size=>:limit, :width=>600, :height=>400, :gravity=>Magick::CenterGravity   },
  'pv'   =>   { :name=>'pv',   :size=>:force, :width=>70,  :height=>70 , :gravity=>Magick::CenterGravity   },
  'edit' =>   { :name=>'edit', :size=>:limit, :width=>400, :height=>400, :gravity=>Magick::CenterGravity   },
  'full' =>   { :name=>'full', :size=>:keep                            , :gravity=>Magick::CenterGravity   },
  nil    =>   { :name=>'full', :size=>:keep                            , :gravity=>Magick::CenterGravity   },
}.freeze

Class Method Summary collapse

Instance Method Summary collapse

Constructor Details

#initialize(h) ⇒ ImageBuilder

Returns a new instance of ImageBuilder.



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# File 'lib/zena/use/image_builder.rb', line 81

def initialize(h)
  params = {:height=>nil, :width=>nil, :path=>nil, :file=>nil, :actions=>[]}.merge(h)
  node = params.delete(:node)

  params.each do |k,v|
    case k
    when :height
      @height = v if v
    when :width
      @width = v if v
    when :path
      @path = v if v
    when :file
      @file = v if v
    when :actions
      if v.kind_of?(Array)
        @actions = v
      else
        raise StandardError, "Bad actions format"
      end
    else
      raise StandardError, "Bad parameter (#{k})"
    end
  end
  unless @width && @height || dummy?
    if @img = build_image_from_file_or_path
      @width  = @img.columns
      @height = @img.rows
      if node && node.respond_to?(:fix_sizes)
        # Fix property
        node.fix_sizes(@width, @height)
      end
    end
  end
end

Class Method Details

.dummy? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/zena/use/image_builder.rb', line 67

def dummy?
  Magick.const_defined?(:ZenaDummy)
end

.hash_id(format) ⇒ Object 



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# File 'lib/zena/use/image_builder.rb', line 71

def hash_id(format)
  Digest::SHA1.hexdigest("#{format[:name]}#{format[:size]}#{format[:width]}#{format[:height]}#{format[:gravity]}")[0..9].to_i(16)
end

.image_content_type?(content_type) ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/zena/use/image_builder.rb', line 63

def image_content_type?(content_type)
  content_type =~ /image/ && !(content_type =~ /svg/)
end

Instance Method Details

#build_image_from_file_or_path ⇒ Object 



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# File 'lib/zena/use/image_builder.rb', line 324

def build_image_from_file_or_path
  if @file || @path
    if @file.kind_of?(StringIO)
      img = Magick::ImageList.new
      @file.rewind
      img.from_blob(@file.read)
      @file.rewind
      @filesize = @file.size
      img
    else
      img = Magick::ImageList.new(@file ? @file.path : @path)
      @filesize = img.filesize
      img
    end
  end
rescue
  nil
end

#columns ⇒ Object Also known as: width 



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# File 'lib/zena/use/image_builder.rb', line 138

def columns
  return nil unless @width || !dummy?
  (@width ||= render_img.columns).round
end

#crop!(x, y, w, h) ⇒ Object 



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# File 'lib/zena/use/image_builder.rb', line 155

def crop!(x,y,w,h)
  @img = nil # reset current rendered image
  @width  = [@width -x, w].min
  @height = [@height-y, h].min
  @actions << Proc.new {|img| img.crop!(x,y,[@img.columns-x, w].min,[@img.rows-y, h].min, true) }
end

#crop_min!(w, h, gravity = Magick::CenterGravity) ⇒ Object 



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# File 'lib/zena/use/image_builder.rb', line 207

def crop_min!(w,h,gravity=Magick::CenterGravity)
  @img = nil # reset current rendered image
  @width  = [@width ,w].min
  @height = [@height,h].min
  @actions << Proc.new {|img| img.crop!(gravity,[@img.columns,w].min,[@img.rows,h].min, true) }
end

#do_limit!(size) ⇒ Object 



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# File 'lib/zena/use/image_builder.rb', line 179

def do_limit!(size)
  return @img if @filesize <= size

  # Check real size
  tmp_path = Tempfile.new('tmp_img').path
  @img.write('jpeg:' + tmp_path)

  return @img if File.stat(tmp_path).size <= size

  # Change type to JPG and quality to 80
  if (@img.format == 'JPG' || @img.format == 'JPEG') && @img.quality > 80
    @img.write('jpeg:' + tmp_path) { self.quality = 80 }
  else
    @img.format = 'JPG'
    @img.write('jpeg:' + tmp_path) { self.quality = 80 }
  end
  ratio = File.stat(tmp_path).size.to_f / size

  return @img = Magick::ImageList.new(tmp_path) if ratio <= 1.0

  # Not enough ? Resize.
  ratio   = 1.0 / Math.sqrt(ratio)
  @width  *= ratio
  @height *= ratio
  @img.resize!(ratio)
  @img
end

#dummy? ⇒ Boolean

Returns:

  • (Boolean) 


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# File 'lib/zena/use/image_builder.rb', line 117

def dummy?
  Zena::Use::ImageBuilder.dummy? || (!@path && !@img && !@file)
end

#exif ⇒ Object 



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# File 'lib/zena/use/image_builder.rb', line 171

def exif
  @exif ||= ExifData.new(render_img.get_exif_by_entry)
end

#format ⇒ Object 



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# File 'lib/zena/use/image_builder.rb', line 167

def format
  render_img.format
end

#format=(fmt) ⇒ Object 



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# File 'lib/zena/use/image_builder.rb', line 162

def format=(fmt)
  return if dummy? || !Magick.formats[fmt.upcase] =~ /w/
  @actions << Proc.new {|img| img.format = fmt.upcase; img }
end

#max_filesize=(size) ⇒ Object 



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# File 'lib/zena/use/image_builder.rb', line 175

def max_filesize=(size)
  @actions << Proc.new {|img| do_limit!(size) }
end

#read ⇒ Object 



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# File 'lib/zena/use/image_builder.rb', line 121

def read
  return nil if dummy?
  render_img
  @img.to_blob
end

#render_img ⇒ Object

Raises:

  • (IOError) 


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# File 'lib/zena/use/image_builder.rb', line 295

def render_img
  raise IOError, 'MagickDummy cannot render image' if Zena::Use::ImageBuilder.dummy?
  unless @img
    unless @img = build_image_from_file_or_path
      raise IOError, 'Cannot render image without path or file'
    end
    if @pre
      @pre = [@pre].flatten
      @pre.each do |a|
        @img = a.call(@img)
      end
    end

    if @actions
      @actions.each do |a|
        @img = a.call(@img)
      end
    end

    if @post
      @post = [@post].flatten
      @post.each do |a|
        @img = a.call(@img)
      end
    end
  end
  @img
end

#resize!(s) ⇒ Object 



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# File 'lib/zena/use/image_builder.rb', line 146

def resize!(s)
  # we do not zoom pixels
  return unless s < 1.0
  @img = nil # reset current rendered image
  @width  *= s
  @height *= s
  @actions << Proc.new {|img| img.resize!(s) }
end

#rows ⇒ Object Also known as: height 



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# File 'lib/zena/use/image_builder.rb', line 133

def rows
  return nil unless @height || !dummy?
  (@height ||= render_img.rows).round
end

#set_background!(opacity, w, h) ⇒ Object 



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# File 'lib/zena/use/image_builder.rb', line 214

def set_background!(opacity,w,h)
  @img = nil # reset current rendered image
  @width  = [@width ,w].max
  @height = [@height,h].max
  @actions << Proc.new do |img|
    bg = Magick::Image.new(w,h)
    bg.opacity = opacity
    bg.format = img.format
    img = bg.composite(img, Magick::CenterGravity, Magick::OverCompositeOp)
  end
end

#transform!(tformat = nil) ⇒ Object

Transform into another format. If nil : do nothing.



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# File 'lib/zena/use/image_builder.rb', line 227

def transform!(tformat=nil)
  return self unless tformat
  @img = nil
  format = { :size=>:limit, :gravity=>Magick::CenterGravity }.merge(tformat)
  @pre, @post = format[:pre], format[:post]

  if format[:size] == :keep
    h,w = @height, @width
  else
    h,w = format[:height], format[:width]
  end
  if format[:scale]
    if h || w
      # scale is a pre-zoom before crop
      scale = format[:scale]
    else
      # we resize to scale
      h,w = @height*format[:scale], @width*format[:scale]
      # but we do not zoom
      scale = 1.0
      # ignore ':size' format if not height nor width was given
      format[:size] = :force
    end
  else
    scale = 1.0
  end
  if format[:ratio] && h && !w
    w = h / format[:ratio]
  elsif format[:ratio] && w && !h
    h = w * format[:ratio]
  end

  pw,ph = @width, @height
  if [w,h,pw,ph].include?(nil) || [w,h,pw,ph].min <= 0
    # image size or thumb size is null (no image processing tool used, no idea on image size)
    if format[:size] == :keep
      @height, @width = nil, nil
    else
      @height, @width = h, w
    end
    return self
  end

  case format[:size]
  when :force
    crop_scale = [w.to_f/pw, h.to_f/ph].max
    if crop_scale > 1.0
      # we do not zoom. Fill with transparent background.
      crop_min!(w,h,format[:gravity])
      set_background!(Magick::MaxRGB, w, h)
    else
      resize!(crop_scale * scale)
      crop_min!(w, h,format[:gravity])
    end
  when :force_no_crop
    crop_scale = [w.to_f/pw, h.to_f/ph].min
    resize!(crop_scale * scale)
    crop_min!(w, h,format[:gravity])
    set_background!(Magick::MaxRGB, w, h)
  when :limit
    crop_scale = [w.to_f/pw, h.to_f/ph].min
    resize!(crop_scale * scale)
    crop_min!(w, h,format[:gravity])
  when :keep
  end
  self
end

#write(path) ⇒ Object 



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# File 'lib/zena/use/image_builder.rb', line 127

def write(path)
  return false if dummy?
  render_img
  @img.write(path)
end