gitlab-org--gitlab-foss/lib/gitlab/diff/inline_diff_marker.rb

115 lines
3.3 KiB
Ruby

module Gitlab
module Diff
class InlineDiffMarker
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(line_inline_diffs)
return rich_line unless line_inline_diffs
marker_ranges = []
line_inline_diffs.each do |inline_diff_range|
# Map the inline-diff range based on the raw line to character positions in the rich line
inline_diff_positions = position_mapping[inline_diff_range].flatten
# Turn the array of character positions into ranges
marker_ranges.concat(collapse_ranges(inline_diff_positions))
end
offset = 0
# Mark each range
marker_ranges.each_with_index do |range, i|
class_names = ["idiff"]
class_names << "left" if i == 0
class_names << "right" if i == marker_ranges.length - 1
offset = insert_around_range(rich_line, range, "<span class='#{class_names.join(" ")}'>", "</span>", offset)
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
# Inserts tags around the characters identified by the given range
def insert_around_range(text, range, before, after, offset = 0)
# Just to be sure
return offset if offset + range.end + 1 > text.length
text.insert(offset + range.begin, before)
offset += before.length
text.insert(offset + range.end + 1, after)
offset += after.length
offset
end
end
end
end