Class: ZPNG::CLI

Inherits:
Object
  • Object
show all
Defined in:
lib/zpng/cli.rb

Constant Summary collapse

ACTIONS = 
{
  'chunks'    => 'Show file chunks (default)',
  %w'i info'      => 'General image info (default)',
  'ascii'     => 'Try to display image as ASCII (works best with monochrome images)',
  'scanlines' => 'Show scanlines info',
  'palette'   => 'Show palette'
}
DEFAULT_ACTIONS = 
%w'info chunks'

Instance Method Summary collapse

Constructor Details

#initialize(argv = ARGV) ⇒ CLI

Returns a new instance of CLI.



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# File 'lib/zpng/cli.rb', line 17

def initialize argv = ARGV
  @argv = argv
end

Instance Method Details

#ascii ⇒ Object 



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# File 'lib/zpng/cli.rb', line 122

def ascii
  puts @img.to_s
end

#chunks ⇒ Object 



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# File 'lib/zpng/cli.rb', line 118

def chunks
  @img.dump
end

#crop(geometry) ⇒ Object 



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# File 'lib/zpng/cli.rb', line 99

def crop geometry
  unless geometry =~ /\A(\d+)x(\d+)\+(\d+)\+(\d+)\Z/i
    STDERR.puts "[!] invalid geometry #{geometry.inspect}, must be WxH+X+Y, like 100x100+10+10"
    exit 1
  end
  @img.crop! :width => $1.to_i, :height => $2.to_i, :x => $3.to_i, :y => $4.to_i
  print @img.export unless @actions.include?(:ascii)
end

#extract_chunk(id) ⇒ Object 



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# File 'lib/zpng/cli.rb', line 82

def extract_chunk id
  @img.chunks.each do |chunk|
    if chunk.idx == id
      case chunk
      when ZPNG::Chunk::ZTXT
        print chunk.text
      else
        print chunk.data
      end
    end
  end
end

#info ⇒ Object 



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# File 'lib/zpng/cli.rb', line 112

def info
  puts "[.] image size #{@img.width || '?'}x#{@img.height || '?'}"
  puts "[.] uncompressed imagedata size = #{@img.imagedata.size} bytes"
  puts "[.] palette = #{@img.palette}" if @img.palette
end

#load_file(fname) ⇒ Object 



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# File 'lib/zpng/cli.rb', line 108

def load_file fname
  @img = ZPNG::Image.new fname
end

#palette ⇒ Object 



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# File 'lib/zpng/cli.rb', line 130

def palette
  if @img.palette
    pp @img.palette
    Hexdump.dump @img.palette.data, :width => 6*3
  end
end

#run ⇒ Object 



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# File 'lib/zpng/cli.rb', line 21

def run
  @actions = []
  @options = { :verbose => 0 }
  optparser = OptionParser.new do |opts|
    opts.banner = "Usage: zpng [options] filename.png"

    opts.on "-v", "--verbose", "Run verbosely (can be used multiple times)" do |v|
      @options[:verbose] += 1
    end
    opts.on "-q", "--quiet", "Silent any warnings (can be used multiple times)" do |v|
      @options[:verbose] -= 1
    end

    ACTIONS.each do |t,desc|
      if t.is_a?(Array)
        opts.on *[ "-#{t[0]}", "--#{t[1]}", desc, eval("lambda{ |_| @actions << :#{t[1]} }") ]
      else
        opts.on *[ "-#{t[0].upcase}", "--#{t}", desc, eval("lambda{ |_| @actions << :#{t} }") ]
      end
    end

    opts.on "-E", "--extract-chunk ID", "extract a single chunk" do |id|
      @actions << [:extract_chunk, id.to_i]
    end
    opts.on "-U", "--unpack-imagedata", "unpack Image Data (IDAT) chunk(s), output to stdout" do
      @actions << :unpack_imagedata
    end

    opts.on "-c", "--crop GEOMETRY", "crop image, {WIDTH}x{HEIGHT}+{X}+{Y},",
    "puts results on stdout unless --ascii given" do |x|
      @actions << [:crop, x]
    end
  end

  if (argv = optparser.parse(@argv)).empty?
    puts optparser.help
    return
  end

  @actions = DEFAULT_ACTIONS if @actions.empty?

  argv.each_with_index do |fname,idx|
    @need_fname_header = (argv.size > 1)
    @file_idx  = idx
    @file_name = fname

    @zpng = load_file fname

    @actions.each do |action|
      if action.is_a?(Array)
        self.send(*action) if self.respond_to?(action.first)
      else
        self.send(action) if self.respond_to?(action)
      end
    end
  end
rescue Errno::EPIPE
  # output interrupt, f.ex. when piping output to a 'head' command
  # prevents a 'Broken pipe - <STDOUT> (Errno::EPIPE)' message
end

#scanlines ⇒ Object 



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# File 'lib/zpng/cli.rb', line 126

def scanlines
  pp @img.scanlines
end

#unpack_imagedata ⇒ Object 



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# File 'lib/zpng/cli.rb', line 95

def unpack_imagedata
  print @img.imagedata
end