convert.rb

# encoding: Shift_JIS
# for Windows
require 'green_shoes'

Sf = %w(png PNG jpg jpeg JPG JPEG gif GIF bmp BMP)

class String
  def imgfile?
    return false unless m = /\.(.+)$/.match(self)
    return m[1] if Sf.include?(m[1])
    false
  end

  def imgsuffix
    Sf.each do |sf|
      a = "." + sf
      return a if include?(a)
    end
    ""
  end
end

Shoes.app width: 500, height: 480 do
  background lavender
  title "画像変換".encode("utf-8")
  
  fname1 = fname2 = ""
  stack height: 120 do
    background azure
    b = button "変換されるファイルを選択".encode("utf-8") do
      fname1 = ask_open_file
    end
    a = para ""
    b.click {a.clear; a = para fname1}
  end
  para "変換先のファイル名".encode("utf-8")
  edit_line(width: 300) {|e| fname2 = e.text}
  button "変換".encode("utf-8") do
    if fname1.imgfile? and fname2.imgfile?
      Dir.chdir(File.dirname(fname1))
      `convert ./#{File.basename(fname1)} ./#{fname2}`
      puts "converted"
      exit
    end
  end
  
  fname3 = ""
  sf1 = sf2 = ""
  para "\n"
  stack height: 120 do
    background moccasin
    para "一括変換するフォルダ".encode("utf-8")
    b1 = button "選択".encode("utf-8") do
      fname3 = ask_open_folder
    end
    a2 = para ""
    b1.click {a2.clear; a2 = para fname3}
  end
  para "画像形式を選択して下さい（変換前/変換後）".encode("utf-8")
  list_box items: ["jpg", "png", "bmp", "gif"] {|t| sf1 = t.text}
  list_box items: ["jpg", "png", "bmp", "gif"] {|t| sf2 = t.text}
  button "変換" do
    if sf1 != sf2
      Dir.chdir(fname3)
      unless File.exist?("converted") and File.directory?("converted")
        Dir.mkdir("converted")
      end
      Dir.chdir(fname3)
      Dir.glob("*").each do |fn1|
        a = fn1.imgsuffix.downcase
        a = ".jpg" if a == ".jpeg"
        if File.file?(fn1) and a == "." + sf1
          fn2 = /(.+)\..+$/.match(fn1)[1] + "." + sf2
          `convert #{fn1} ./converted/#{fn2}`
        end
      end
      puts "converted"
      exit
    end
  end
end