diff options
Diffstat (limited to 'lib/gitlab/string_range_marker.rb')
-rw-r--r-- | lib/gitlab/string_range_marker.rb | 102 |
1 files changed, 102 insertions, 0 deletions
diff --git a/lib/gitlab/string_range_marker.rb b/lib/gitlab/string_range_marker.rb new file mode 100644 index 00000000000..94fba0a221a --- /dev/null +++ b/lib/gitlab/string_range_marker.rb @@ -0,0 +1,102 @@ +module Gitlab + class StringRangeMarker + attr_accessor :raw_line, :rich_line + + def initialize(raw_line, rich_line = raw_line) + @raw_line = raw_line + @rich_line = ERB::Util.html_escape(rich_line) + end + + def mark(marker_ranges) + return rich_line unless marker_ranges + + rich_marker_ranges = [] + marker_ranges.each do |range| + # Map the inline-diff range based on the raw line to character positions in the rich line + rich_positions = position_mapping[range].flatten + # Turn the array of character positions into ranges + rich_marker_ranges.concat(collapse_ranges(rich_positions)) + end + + offset = 0 + # Mark each range + rich_marker_ranges.each_with_index do |range, i| + offset_range = (range.begin + offset)..(range.end + offset) + original_text = rich_line[offset_range] + + text = yield(original_text, left: i == 0, right: i == rich_marker_ranges.length - 1) + + rich_line[offset_range] = text + + offset += text.length - original_text.length + end + + rich_line.html_safe + end + + private + + # Mapping of character positions in the raw line, to the rich (highlighted) line + def position_mapping + @position_mapping ||= begin + mapping = [] + rich_pos = 0 + (0..raw_line.length).each do |raw_pos| + rich_char = rich_line[rich_pos] + + # The raw and rich lines are the same except for HTML tags, + # so skip over any `<...>` segment + while rich_char == '<' + until rich_char == '>' + rich_pos += 1 + rich_char = rich_line[rich_pos] + end + + rich_pos += 1 + rich_char = rich_line[rich_pos] + end + + # multi-char HTML entities in the rich line correspond to a single character in the raw line + if rich_char == '&' + multichar_mapping = [rich_pos] + until rich_char == ';' + rich_pos += 1 + multichar_mapping << rich_pos + rich_char = rich_line[rich_pos] + end + + mapping[raw_pos] = multichar_mapping + else + mapping[raw_pos] = rich_pos + end + + rich_pos += 1 + end + + mapping + end + end + + # Takes an array of integers, and returns an array of ranges covering the same integers + def collapse_ranges(positions) + return [] if positions.empty? + ranges = [] + + start = prev = positions[0] + range = start..prev + positions[1..-1].each do |pos| + if pos == prev + 1 + range = start..pos + prev = pos + else + ranges << range + start = prev = pos + range = start..prev + end + end + ranges << range + + ranges + end + end +end |