run gifsicle two times: one with interlace off and one with on for be…

…st result, resolves #70

README.markdown

@@ -273,7 +273,7 @@ Worker can be disabled by passing `false` instead of options hash.
 * `:level` — Compression level: `0` - don't compress, `1` - fast, `2` - normal, `3` - extra, `4` - extreme *(defaults to `4`)*
 
 ### :gifsicle =>
-* `:interlace` — Interlace: `true` - interlace on, `false` - interlace off, `nil` - as is in original image *(defaults to `false`)*
+* `:interlace` — Interlace: `true` - interlace on, `false` - interlace off, `nil` - as is in original image (defaults to running two instances, one with interlace off and one with on) *(defaults to `false`)*
 * `:level` — Compression level: `1` - light and fast, `2` - normal, `3` - heavy (slower) *(defaults to `3`)*
 * `:careful` — Avoid bugs with some software *(defaults to `false`)*
 

lib/image_optim/runner/option_parser.rb

@@ -180,12 +180,12 @@ def wrap_regex(width)
         fail "Unknown type #{type}"
       end
 
-      description_lines = %W[
-        #{option_definition.description.gsub(' - ', ' - ')}
-        (defaults to #{default})
-      ].join(' ')
+      description = option_definition.description.gsub(' - ', ' - ')
+      unless description['(defaults']
+        description << " (defaults to #{default})"
+      end
 
-      op.on("--#{bin}-#{name} #{marking}", type, *description_lines) do |value|
+      op.on("--#{bin}-#{name} #{marking}", type, description) do |value|
         options[bin] = {} unless options[bin].is_a?(Hash)
         options[bin][option_definition.name.to_sym] = value
       end

lib/image_optim/worker.rb

@@ -15,6 +15,7 @@ class Worker
 
     class << self
       # Default init for worker is new
+      # Check example of override in gifsicle worker
       alias_method :init, :new
 
       # List of available workers

lib/image_optim/worker/gifsicle.rb

@@ -4,11 +4,23 @@ class ImageOptim
   class Worker
     # http://www.lcdf.org/gifsicle/
     class Gifsicle < Worker
+      # If interlace specified initialize one instance
+      # Otherwise initialize two, one with interlace off and one with on
+      def self.init(image_optim, options)
+        return super if options.key?(:interlace)
+
+        [false, true].map do |interlace|
+          new(image_optim, options.merge(:interlace => interlace))
+        end
+      end
+
       INTERLACE_OPTION =
       option(:interlace, false, TrueFalseNil, 'Interlace: '\
           '`true` - interlace on, '\
           '`false` - interlace off, '\
-          '`nil` - as is in original image') do |v|
+          '`nil` - as is in original image '\
+          '(defaults to running two instances, one with interlace off and '\
+          'one with on)') do |v|
         TrueFalseNil.convert(v)
       end
 

script/update_worker_options_in_readme

@@ -17,12 +17,11 @@ def write_worker_options(io, klass)
     io.puts 'Worker has no options'
   else
     klass.option_definitions.each do |option_definition|
-      io.puts %W[
-        *
-        `:#{option_definition.name}`
-        — #{option_definition.description}
-        *(defaults to `#{option_definition.default.inspect}`)*
-      ].join(' ')
+      line = "* `:#{option_definition.name}` — #{option_definition.description}"
+      unless line['(defaults']
+        line << " *(defaults to `#{option_definition.default.inspect}`)*"
+      end
+      io.puts line
     end
   end
   io.puts