Fresh start

1 files changed, 343 insertions, 0 deletions

diff --git a/jni/ruby/lib/rdoc/markup/attribute_manager.rb b/jni/ruby/lib/rdoc/markup/attribute_manager.rb
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+++ b/jni/ruby/lib/rdoc/markup/attribute_manager.rb
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+##
+# Manages changes of attributes in a block of text
+
+class RDoc::Markup::AttributeManager
+
+  ##
+  # The NUL character
+
+  NULL = "\000".freeze
+
+  #--
+  # We work by substituting non-printing characters in to the text. For now
+  # I'm assuming that I can substitute a character in the range 0..8 for a 7
+  # bit character without damaging the encoded string, but this might be
+  # optimistic
+  #++
+
+  A_PROTECT = 004 # :nodoc:
+
+  ##
+  # Special mask character to prevent inline markup handling
+
+  PROTECT_ATTR = A_PROTECT.chr # :nodoc:
+
+  ##
+  # The attributes enabled for this markup object.
+
+  attr_reader :attributes
+
+  ##
+  # This maps delimiters that occur around words (such as *bold* or +tt+)
+  # where the start and end delimiters and the same. This lets us optimize
+  # the regexp
+
+  attr_reader :matching_word_pairs
+
+  ##
+  # And this is used when the delimiters aren't the same. In this case the
+  # hash maps a pattern to the attribute character
+
+  attr_reader :word_pair_map
+
+  ##
+  # This maps HTML tags to the corresponding attribute char
+
+  attr_reader :html_tags
+
+  ##
+  # A \ in front of a character that would normally be processed turns off
+  # processing. We do this by turning \< into <#{PROTECT}
+
+  attr_reader :protectable
+
+  ##
+  # And this maps _special_ sequences to a name. A special sequence is
+  # something like a WikiWord
+
+  attr_reader :special
+
+  ##
+  # Creates a new attribute manager that understands bold, emphasized and
+  # teletype text.
+
+  def initialize
+    @html_tags = {}
+    @matching_word_pairs = {}
+    @protectable = %w[<]
+    @special = []
+    @word_pair_map = {}
+    @attributes = RDoc::Markup::Attributes.new
+
+    add_word_pair "*", "*", :BOLD
+    add_word_pair "_", "_", :EM
+    add_word_pair "+", "+", :TT
+
+    add_html "em", :EM
+    add_html "i",  :EM
+    add_html "b",  :BOLD
+    add_html "tt",   :TT
+    add_html "code", :TT
+  end
+
+  ##
+  # Return an attribute object with the given turn_on and turn_off bits set
+
+  def attribute(turn_on, turn_off)
+    RDoc::Markup::AttrChanger.new turn_on, turn_off
+  end
+
+  ##
+  # Changes the current attribute from +current+ to +new+
+
+  def change_attribute current, new
+    diff = current ^ new
+    attribute(new & diff, current & diff)
+  end
+
+  ##
+  # Used by the tests to change attributes by name from +current_set+ to
+  # +new_set+
+
+  def changed_attribute_by_name current_set, new_set
+    current = new = 0
+    current_set.each do |name|
+      current |= @attributes.bitmap_for(name)
+    end
+
+    new_set.each do |name|
+      new |= @attributes.bitmap_for(name)
+    end
+
+    change_attribute(current, new)
+  end
+
+  ##
+  # Copies +start_pos+ to +end_pos+ from the current string
+
+  def copy_string(start_pos, end_pos)
+    res = @str[start_pos...end_pos]
+    res.gsub!(/\000/, '')
+    res
+  end
+
+  ##
+  # Map attributes like <b>text</b>to the sequence
+  # \001\002<char>\001\003<char>, where <char> is a per-attribute specific
+  # character
+
+  def convert_attrs(str, attrs)
+    # first do matching ones
+    tags = @matching_word_pairs.keys.join("")
+
+    re = /(^|\W)([#{tags}])([#\\]?[\w:.\/-]+?\S?)\2(\W|$)/
+
+    1 while str.gsub!(re) do
+      attr = @matching_word_pairs[$2]
+      attrs.set_attrs($`.length + $1.length + $2.length, $3.length, attr)
+      $1 + NULL * $2.length + $3 + NULL * $2.length + $4
+    end
+
+    # then non-matching
+    unless @word_pair_map.empty? then
+      @word_pair_map.each do |regexp, attr|
+        str.gsub!(regexp) {
+          attrs.set_attrs($`.length + $1.length, $2.length, attr)
+          NULL * $1.length + $2 + NULL * $3.length
+        }
+      end
+    end
+  end
+
+  ##
+  # Converts HTML tags to RDoc attributes
+
+  def convert_html(str, attrs)
+    tags = @html_tags.keys.join '|'
+
+    1 while str.gsub!(/<(#{tags})>(.*?)<\/\1>/i) {
+      attr = @html_tags[$1.downcase]
+      html_length = $1.length + 2
+      seq = NULL * html_length
+      attrs.set_attrs($`.length + html_length, $2.length, attr)
+      seq + $2 + seq + NULL
+    }
+  end
+
+  ##
+  # Converts special sequences to RDoc attributes
+
+  def convert_specials str, attrs
+    @special.each do |regexp, attribute|
+      str.scan(regexp) do
+        capture = $~.size == 1 ? 0 : 1
+
+        s, e = $~.offset capture
+
+        attrs.set_attrs s, e - s, attribute | @attributes.special
+      end
+    end
+  end
+
+  ##
+  # Escapes special sequences of text to prevent conversion to RDoc
+
+  def mask_protected_sequences
+    # protect __send__, __FILE__, etc.
+    @str.gsub!(/__([a-z]+)__/i,
+      "_#{PROTECT_ATTR}_#{PROTECT_ATTR}\\1_#{PROTECT_ATTR}_#{PROTECT_ATTR}")
+    @str.gsub!(/(\A|[^\\])\\([#{Regexp.escape @protectable.join}])/m,
+               "\\1\\2#{PROTECT_ATTR}")
+    @str.gsub!(/\\(\\[#{Regexp.escape @protectable.join}])/m, "\\1")
+  end
+
+  ##
+  # Unescapes special sequences of text
+
+  def unmask_protected_sequences
+    @str.gsub!(/(.)#{PROTECT_ATTR}/, "\\1\000")
+  end
+
+  ##
+  # Adds a markup class with +name+ for words wrapped in the +start+ and
+  # +stop+ character.  To make words wrapped with "*" bold:
+  #
+  #   am.add_word_pair '*', '*', :BOLD
+
+  def add_word_pair(start, stop, name)
+    raise ArgumentError, "Word flags may not start with '<'" if
+      start[0,1] == '<'
+
+    bitmap = @attributes.bitmap_for name
+
+    if start == stop then
+      @matching_word_pairs[start] = bitmap
+    else
+      pattern = /(#{Regexp.escape start})(\S+)(#{Regexp.escape stop})/
+      @word_pair_map[pattern] = bitmap
+    end
+
+    @protectable << start[0,1]
+    @protectable.uniq!
+  end
+
+  ##
+  # Adds a markup class with +name+ for words surrounded by HTML tag +tag+.
+  # To process emphasis tags:
+  #
+  #   am.add_html 'em', :EM
+
+  def add_html(tag, name)
+    @html_tags[tag.downcase] = @attributes.bitmap_for name
+  end
+
+  ##
+  # Adds a special handler for +pattern+ with +name+.  A simple URL handler
+  # would be:
+  #
+  #   @am.add_special(/((https?:)\S+\w)/, :HYPERLINK)
+
+  def add_special pattern, name
+    @special << [pattern, @attributes.bitmap_for(name)]
+  end
+
+  ##
+  # Processes +str+ converting attributes, HTML and specials
+
+  def flow str
+    @str = str
+
+    mask_protected_sequences
+
+    @attrs = RDoc::Markup::AttrSpan.new @str.length
+
+    convert_attrs    @str, @attrs
+    convert_html     @str, @attrs
+    convert_specials @str, @attrs
+
+    unmask_protected_sequences
+
+    split_into_flow
+  end
+
+  ##
+  # Debug method that prints a string along with its attributes
+
+  def display_attributes
+    puts
+    puts @str.tr(NULL, "!")
+    bit = 1
+    16.times do |bno|
+      line = ""
+      @str.length.times do |i|
+        if (@attrs[i] & bit) == 0
+          line << " "
+        else
+          if bno.zero?
+            line << "S"
+          else
+            line << ("%d" % (bno+1))
+          end
+        end
+      end
+      puts(line) unless line =~ /^ *$/
+      bit <<= 1
+    end
+  end
+
+  ##
+  # Splits the string into chunks by attribute change
+
+  def split_into_flow
+    res = []
+    current_attr = 0
+
+    str_len = @str.length
+
+    # skip leading invisible text
+    i = 0
+    i += 1 while i < str_len and @str[i].chr == "\0"
+    start_pos = i
+
+    # then scan the string, chunking it on attribute changes
+    while i < str_len
+      new_attr = @attrs[i]
+      if new_attr != current_attr
+        if i > start_pos
+          res << copy_string(start_pos, i)
+          start_pos = i
+        end
+
+        res << change_attribute(current_attr, new_attr)
+        current_attr = new_attr
+
+        if (current_attr & @attributes.special) != 0 then
+          i += 1 while
+            i < str_len and (@attrs[i] & @attributes.special) != 0
+
+          res << RDoc::Markup::Special.new(current_attr,
+                                           copy_string(start_pos, i))
+          start_pos = i
+          next
+        end
+      end
+
+      # move on, skipping any invisible characters
+      begin
+        i += 1
+      end while i < str_len and @str[i].chr == "\0"
+    end
+
+    # tidy up trailing text
+    if start_pos < str_len
+      res << copy_string(start_pos, str_len)
+    end
+
+    # and reset to all attributes off
+    res << change_attribute(current_attr, 0) if current_attr != 0
+
+    res
+  end
+
+end
+