Vulkan-Docs/config/extension-highlighter/extension.rb

314 lines
12 KiB
Ruby

# Copyright (c) 2016-2018 The Khronos Group Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
require 'asciidoctor/extensions' unless RUBY_ENGINE == 'opal'
include ::Asciidoctor
module Asciidoctor
# Duplicate of "AnyListRx" defined by asciidoctor
# Detects the start of any list item.
#
# NOTE we only have to check as far as the blank character because we know it means non-whitespace follows.
HighlighterAnyListRx = /^(?:#{CG_BLANK}*(?:-|([*.\u2022])\1{0,4}|\d+\.|[a-zA-Z]\.|[IVXivx]+\))#{CG_BLANK}|#{CG_BLANK}*.*?(?::{2,4}|;;)(?:$|#{CG_BLANK})|<?\d+>#{CG_BLANK})/
class ExtensionHighlighterPreprocessorReader < PreprocessorReader
def initialize document, diff_extensions, data = nil, cursor = nil
super(document, data, cursor)
@status_stack = []
@diff_extensions = diff_extensions
@tracking_target = nil
end
# This overrides the default preprocessor reader conditional logic such
# that any extensions which need highlighting and are enabled have their
# ifdefs left intact.
def preprocess_conditional_directive directive, target, delimiter, text
# If we're tracking a target for highlighting already, don't need to do
# additional processing unless we hit the end of that conditional
# section
# NOTE: This will break if for some absurd reason someone nests the same
# conditional inside itself.
if @tracking_target != nil && directive == 'endif' && @tracking_target == target.downcase
@tracking_target = nil
elsif @tracking_target
return super(directive, target, delimiter, text)
end
# If it's an ifdef or ifndef, push the directive onto a stack
# If it's an endif, pop the last one off.
# This is done to apply the next bit of logic to both the start and end
# of an conditional block correctly
status = directive
if directive == 'endif'
status = @status_stack.pop
else
@status_stack.push status
end
# If the status is negative, we need to still include the conditional
# text for the highlighter, so we replace the requirement for the
# extension attribute in question to be not defined with an
# always-undefined attribute, so that it evaluates to true when it needs
# to.
# Undefined attribute is currently just the extension with "_undefined"
# appended to it.
modified_target = target.downcase
if status == 'ifndef'
@diff_extensions.each do | extension |
modified_target.gsub!(extension, extension + '_undefined')
end
end
# Call the original preprocessor
result = super(directive, modified_target, delimiter, text)
# If any of the extensions are in the target, and the conditional text
# isn't flagged to be skipped, return false to prevent the preprocessor
# from removing the line from the processed source.
unless @skipping
@diff_extensions.each do | extension |
if target.downcase.include?(extension)
if directive != 'endif'
@tracking_target = target.downcase
end
return false
end
end
end
return result
end
# Identical to preprocess_conditional_directive, but older versions of
# Asciidoctor used a different name, so this is there to override the same
# method in older versions.
# This is a pure c+p job for awkward inheritance reasons (see use of
# the super() keyword :|)
# At some point, will rewrite to avoid this mess, but this fixes things
# for now without breaking things for anyone.
def preprocess_conditional_inclusion directive, target, delimiter, text
# If we're tracking a target for highlighting already, don't need to do
# additional processing unless we hit the end of that conditional
# section
# NOTE: This will break if for some absurd reason someone nests the same
# conditional inside itself.
if @tracking_target != nil && directive == 'endif' && @tracking_target == target.downcase
@tracking_target = nil
elsif @tracking_target
return super(directive, target, delimiter, text)
end
# If it's an ifdef or ifndef, push the directive onto a stack
# If it's an endif, pop the last one off.
# This is done to apply the next bit of logic to both the start and end
# of an conditional block correctly
status = directive
if directive == 'endif'
status = @status_stack.pop
else
@status_stack.push status
end
# If the status is negative, we need to still include the conditional
# text for the highlighter, so we replace the requirement for the
# extension attribute in question to be not defined with an
# always-undefined attribute, so that it evaluates to true when it needs
# to.
# Undefined attribute is currently just the extension with "_undefined"
# appended to it.
modified_target = target.downcase
if status == 'ifndef'
@diff_extensions.each do | extension |
modified_target.gsub!(extension, extension + '_undefined')
end
end
# Call the original preprocessor
result = super(directive, modified_target, delimiter, text)
# If any of the extensions are in the target, and the conditional text
# isn't flagged to be skipped, return false to prevent the preprocessor
# from removing the line from the processed source.
unless @skipping
@diff_extensions.each do | extension |
if target.downcase.include?(extension)
if directive != 'endif'
@tracking_target = target.downcase
end
return false
end
end
end
return result
end
end
class Highlighter
def initialize
@delimiter_stack = []
@current_anchor = 1
end
def highlight_marks line, previous_line, next_line
if !(line.start_with? 'endif')
# Any intact "ifdefs" are sections added by an extension, and
# "ifndefs" are sections removed.
# Currently don't track *which* extension(s) is/are responsible for
# the addition or removal - though it would be possible to add it.
if line.start_with? 'ifdef'
role = 'added'
else # if line.start_with? 'ifndef'
role = 'removed'
end
# Create an anchor with the current anchor number
anchor = '[[difference' + @current_anchor.to_s + ']]'
# Figure out which markup to use based on the surrounding text
# This is robust enough as far as I can tell, though we may want to do
# something more generic later since currently it relies on the fact
# that if you start inside a list or paragraph, you'll end in the same
# list or paragraph and not cross to other blocks.
# In practice it *might just work* but it also might not.
# May need to consider what to do about this in future - maybe just
# use open blocks for everything?
highlight_delimiter = :inline
if (HighlighterAnyListRx.match(next_line) != nil)
# NOTE: There's a corner case here that should never be hit (famous last words)
# If a line in the middle of a paragraph begins with an asterisk and
# then whitespace, this will think it's a list item and use the
# wrong delimiter.
# That shouldn't be a problem in practice though, it just might look
# a little weird.
highlight_delimiter = :list
elsif previous_line.strip.empty?
highlight_delimiter = :block
end
# Add the delimiter to the stack for the matching 'endif' to consume
@delimiter_stack.push highlight_delimiter
# Add an appropriate method of delimiting the highlighted areas based
# on the surrounding text determined above.
if highlight_delimiter == :block
return ['', anchor, ":role: #{role}", '']
elsif highlight_delimiter == :list
return ['', anchor, "[.#{role}]", '~~~~~~~~~~~~~~~~~~~~', '']
else #if highlight_delimiter == :inline
return [anchor + ' [.' + role + ']##']
end
else # if !(line.start_with? 'endif')
# Increment the anchor when we see a matching endif, and generate a
# link to the next diff section
@current_anchor = @current_anchor + 1
anchor_link = '<<difference' + @current_anchor.to_s + ', =>>>'
# Close the delimited area according to the previously determined
# delimiter
highlight_delimiter = @delimiter_stack.pop
if highlight_delimiter == :block
return [anchor_link, '', ':role:', '']
elsif highlight_delimiter == :list
return [anchor_link, '~~~~~~~~~~~~~~~~~~~~', '']
else #if highlight_delimiter == :inline
return [anchor_link + '##']
end
end
end
end
# Preprocessor hook to iterate over ifdefs to prevent them from affecting asciidoctor's processing.
class ExtensionHighlighterPreprocessor < Extensions::Preprocessor
def process document, reader
# Only attempt to highlight extensions that are also enabled - if one
# isn't, warn about it and skip highlighting that extension.
diff_extensions = document.attributes['diff_extensions'].downcase.split(' ')
actual_diff_extensions = []
diff_extensions.each do | extension |
if document.attributes.has_key?(extension)
actual_diff_extensions << extension
else
puts 'The ' + extension + ' extension is not enabled - changes will not be highlighted.'
end
end
# Create a new reader to return, which leaves extension ifdefs that need highlighting intact beyond the preprocess step.
extension_preprocessor_reader = ExtensionHighlighterPreprocessorReader.new(document, actual_diff_extensions, reader.lines)
highlighter = Highlighter.new
new_lines = []
# Store the old lines so we can reference them in a non-trivial fashion
old_lines = extension_preprocessor_reader.read_lines()
old_lines.each_index do | index |
# Grab the previously processed line
# This is used by the highlighter to figure out if the highlight will
# be inline, or part of a block.
if index > 0
previous_line = old_lines[index - 1]
else
previous_line = ''
end
# Current line to process
line = old_lines[index]
# Grab the next line to process
# This is used by the highlighter to figure out if the highlight is
# between list elements or not - which need special handling.
if index < (old_lines.length - 1)
next_line = old_lines[index + 1]
else
next_line = ''
end
# Highlight any preprocessor directives that were left intact by the
# custom preprocessor reader.
if line.start_with?( 'ifdef::', 'ifndef::', 'endif::')
new_lines += highlighter.highlight_marks(line, previous_line, next_line)
else
new_lines << line
end
end
# Return a new reader after preprocessing - this takes care of creating
# the AST from the new source.
Reader.new(new_lines)
end
end
class AddHighlighterCSS < Extensions::Postprocessor
HighlighterStyleCSS = [
'.added {',
' background-color: lime;',
' border-color: green;',
' padding:1px;',
'}',
'.removed {',
' background-color: pink;',
' border-color: red;',
' padding:1px;',
'}',
'</style>']
def process document, output
output.sub! '</style>', HighlighterStyleCSS.join("\n")
end
end
end