Add experimental progressive mode

lib/youplot/command.rb

@@ -32,9 +32,15 @@ module YouPlot
         plot = create_plot
         output_plot(plot)
       else
-        # Sometimes the input file does not end with a newline code.
-        while (input = Kernel.gets(nil))
-          main(input)
+        if options[:progressive]
+          while (input = Kernel.gets)
+            main_progress(input)
+          end
+        else
+          # Sometimes the input file does not end with a newline code.
+          while (input = Kernel.gets(nil))
+            main(input)
+          end
         end
       end
     end
@@ -52,6 +58,18 @@ module YouPlot
       output_plot(plot)
     end
 
+    def main_progress(input)
+      output_data(input)
+
+      @raw_data ||= String.new
+      @raw_data << input
+      
+      @data = read_dsv(@raw_data)
+
+      plot = create_plot
+      output_plot_progressive(plot)
+    end
+
     def read_dsv(input)
       input = input.dup.force_encoding(options[:encoding]).encode('utf-8') if options[:encoding]
       DSV.parse(input, options[:delimiter], options[:headers], options[:transpose])
@@ -106,5 +124,27 @@ module YouPlot
         end
       end
     end
+
+    def output_plot_progressive(plot)
+      case options[:output]
+      when IO
+        # RefactorMe
+        @output_stringio = StringIO.new(String.new)
+        def @output_stringio.tty?; true; end
+        out = @output_stringio.clone
+        plot.render(out)
+        lines = out.string.lines
+        lines.each do |line|
+          options[:output].print line.chomp
+          options[:output].print "\e[0K"
+          options[:output].puts
+        end
+        options[:output].flush
+        n = out.string.lines.size
+        options[:output].print "\e[#{n}F"
+      else
+        raise "In progressive mode, output to a file is not possible."
+      end
+    end
   end
 end

lib/youplot/command/options.rb

@@ -7,6 +7,7 @@ module YouPlot
       :transpose,
       :headers,
       :pass,
+      :progressive,
       :output,
       :fmt,
       :encoding,

lib/youplot/command/parser.rb

@@ -82,7 +82,7 @@ module YouPlot
           opt.on('--[no-]labels', TrueClass, 'hide the labels') do |v|
             params.labels = v
           end
-          opt.on('--progress', TrueClass, 'progressive') do |v|
+          opt.on('--progress', TrueClass, 'progressive mode [experimental]') do |v|
             @options[:progressive] = v
           end
           opt.on('--encoding VAL', String, 'Specify the input encoding') do |v|