comparison vendor/gems/coderay-0.9.7/lib/coderay/.svn/text-base/encoder.rb.svn-base @ 210:0579821a129a

Update to Redmine trunk rev 4802

+module CodeRay
+
+  # This module holds the Encoder class and its subclasses.
+  # For example, the HTML encoder is named CodeRay::Encoders::HTML
+  # can be found in coderay/encoders/html.
+  #
+  # Encoders also provides methods and constants for the register
+  # mechanism and the [] method that returns the Encoder class
+  # belonging to the given format.
+  module Encoders
+    extend PluginHost
+    plugin_path File.dirname(__FILE__), 'encoders'
+
+    # = Encoder
+    #
+    # The Encoder base class. Together with Scanner and
+    # Tokens, it forms the highlighting triad.
+    #
+    # Encoder instances take a Tokens object and do something with it.
+    #
+    # The most common Encoder is surely the HTML encoder
+    # (CodeRay::Encoders::HTML). It highlights the code in a colorful
+    # html page.
+    # If you want the highlighted code in a div or a span instead,
+    # use its subclasses Div and Span.
+    class Encoder
+      extend Plugin
+      plugin_host Encoders
+
+      attr_reader :token_stream
+
+      class << self
+
+        # Returns if the Encoder can be used in streaming mode.
+        def streamable?
+          is_a? Streamable
+        end
+
+        # If FILE_EXTENSION isn't defined, this method returns the
+        # downcase class name instead.
+        def const_missing sym
+          if sym == :FILE_EXTENSION
+            plugin_id
+          else
+            super
+          end
+        end
+
+      end
+
+      # Subclasses are to store their default options in this constant.
+      DEFAULT_OPTIONS = { :stream => false }
+
+      # The options you gave the Encoder at creating.
+      attr_accessor :options
+
+      # Creates a new Encoder.
+      # +options+ is saved and used for all encode operations, as long
+      # as you don't overwrite it there by passing additional options.
+      #
+      # Encoder objects provide three encode methods:
+      # - encode simply takes a +code+ string and a +lang+
+      # - encode_tokens expects a +tokens+ object instead
+      # - encode_stream is like encode, but uses streaming mode.
+      #
+      # Each method has an optional +options+ parameter. These are
+      # added to the options you passed at creation.
+      def initialize options = {}
+        @options = self.class::DEFAULT_OPTIONS.merge options
+        raise "I am only the basic Encoder class. I can't encode "\
+          "anything. :( Use my subclasses." if self.class == Encoder
+      end
+
+      # Encode a Tokens object.
+      def encode_tokens tokens, options = {}
+        options = @options.merge options
+        setup options
+        compile tokens, options
+        finish options
+      end
+
+      # Encode the given +code+ after tokenizing it using the Scanner
+      # for +lang+.
+      def encode code, lang, options = {}
+        options = @options.merge options
+        scanner_options = CodeRay.get_scanner_options(options)
+        tokens = CodeRay.scan code, lang, scanner_options
+        encode_tokens tokens, options
+      end
+
+      # You can use highlight instead of encode, if that seems
+      # more clear to you.
+      alias highlight encode
+
+      # Encode the given +code+ using the Scanner for +lang+ in
+      # streaming mode.
+      def encode_stream code, lang, options = {}
+        raise NotStreamableError, self unless kind_of? Streamable
+        options = @options.merge options
+        setup options
+        scanner_options = CodeRay.get_scanner_options options
+        @token_stream =
+          CodeRay.scan_stream code, lang, scanner_options, &self
+        finish options
+      end
+
+      # Behave like a proc. The token method is converted to a proc.
+      def to_proc
+        method(:token).to_proc
+      end
+
+      # Return the default file extension for outputs of this encoder.
+      def file_extension
+        self.class::FILE_EXTENSION
+      end
+
+    protected
+
+      # Called with merged options before encoding starts.
+      # Sets @out to an empty string.
+      #
+      # See the HTML Encoder for an example of option caching.
+      def setup options
+        @out = ''
+      end
+
+      # Called with +content+ and +kind+ of the currently scanned token.
+      # For simple scanners, it's enougth to implement this method.
+      #
+      # By default, it calls text_token or block_token, depending on
+      # whether +content+ is a String.
+      def token content, kind
+        encoded_token =
+          if content.is_a? ::String
+            text_token content, kind
+          elsif content.is_a? ::Symbol
+            block_token content, kind
+          else
+            raise 'Unknown token content type: %p' % [content]
+          end
+        append_encoded_token_to_output encoded_token
+      end
+      
+      def append_encoded_token_to_output encoded_token
+        @out << encoded_token if encoded_token && defined?(@out) && @out
+      end
+      
+      # Called for each text token ([text, kind]), where text is a String.
+      def text_token text, kind
+      end
+      
+      # Called for each block (non-text) token ([action, kind]),
+      # where +action+ is a Symbol.
+      # 
+      # Calls open_token, close_token, begin_line, and end_line according to
+      # the value of +action+.
+      def block_token action, kind
+        case action
+        when :open
+          open_token kind
+        when :close
+          close_token kind
+        when :begin_line
+          begin_line kind
+        when :end_line
+          end_line kind
+        else
+          raise 'unknown block action: %p' % action
+        end
+      end
+      
+      # Called for each block token at the start of the block ([:open, kind]).
+      def open_token kind
+      end
+      
+      # Called for each block token end of the block ([:close, kind]).
+      def close_token kind
+      end
+      
+      # Called for each line token block at the start of the line ([:begin_line, kind]).
+      def begin_line kind
+      end
+      
+      # Called for each line token block at the end of the line ([:end_line, kind]).
+      def end_line kind
+      end
+
+      # Called with merged options after encoding starts.
+      # The return value is the result of encoding, typically @out.
+      def finish options
+        @out
+      end
+
+      # Do the encoding.
+      #
+      # The already created +tokens+ object must be used; it can be a
+      # TokenStream or a Tokens object.
+      if RUBY_VERSION >= '1.9'
+        def compile tokens, options
+          for text, kind in tokens
+            token text, kind
+          end
+        end
+      else
+        def compile tokens, options
+          tokens.each(&self)
+        end
+      end
+
+    end
+
+  end
+end