Completed markdown plugin; pre-work on snippits; renamed sourceview file to align with other names

plugins/autopairs/plugin.py

@@ -72,39 +72,14 @@ class Plugin(PluginBase):
         self._buffer          = self._active_src_view.get_buffer()
         self._tag_table       = self._buffer.get_tag_table()
 
-    def _buffer_changed_first_load(self, buffer):
-        self._do_colorize(buffer)
-
-
-    def _buffer_changed(self, buffer):
-        tag_table = buffer.get_tag_table()
-        mark      = buffer.get_insert()
-        iter      = buffer.get_iter_at_mark(mark)
-        tags      = iter.get_tags()
-
     def _autopairs(self, keyval_name, ctrl, alt, shift):
         if keyval_name in self.chars:
             return self.text_insert(self._buffer, keyval_name)
-        elif ctrl and keyval_name == "Return":
-            self.move_to_next_line(self._buffer)
 
     # NOTE: All of below to EOF, lovingly taken from Hamad Al Marri's Gamma
     #       text editor. I did do some cleanup of comments but otherwise pretty
     #       much the same code just fitted to my plugin architecture.
     # Link: https://gitlab.com/hamadmarri/gamma-text-editor
-    def move_to_next_line(self, buffer):
-        selection = buffer.get_selection_bounds()
-        if selection != (): return False
-
-        position = buffer.get_iter_at_mark(buffer.get_insert())
-
-        if position.ends_line(): return False
-
-        position.forward_to_line_end()
-        buffer.place_cursor(position)
-
-        return False
-
     def text_insert(self, buffer, text):
         selection = buffer.get_selection_bounds()
         if selection == ():
@@ -116,7 +91,7 @@ class Plugin(PluginBase):
         text = self.chars[text]
         text += self.close[text]
 
-        position = buffer.get_iter_at_mark(buffer.get_insert())
+        position = buffer.get_iter_at_mark( buffer.get_insert() )
 
         c = position.get_char()
         if not c in (" ", "", ";", ":", "\t", ",", ".", "\n", "\r") \

plugins/markdown_preview/markdown/__init__.py

@@ -0,0 +1,48 @@
+# Python Markdown
+
+# A Python implementation of John Gruber's Markdown.
+
+# - Documentation: https://python-markdown.github.io/
+# - GitHub: https://github.com/Python-Markdown/markdown/
+# - PyPI: https://pypi.org/project/Markdown/
+
+# Started by Manfred Stienstra (http://www.dwerg.net/).
+# Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
+# Currently maintained by Waylan Limberg (https://github.com/waylan),
+# Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
+
+# - Copyright 2007-2023 The Python Markdown Project (v. 1.7 and later)
+# - Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
+# - Copyright 2004 Manfred Stienstra (the original version)
+
+# License: BSD (see LICENSE.md for details).
+
+"""
+Python-Markdown provides two public functions ([`markdown.markdown`][] and [`markdown.markdownFromFile`][])
+both of which wrap the public class [`markdown.Markdown`][]. All submodules support these public functions
+and class and/or provide extension support.
+
+Modules:
+    core: Core functionality.
+    preprocessors: Pre-processors.
+    blockparser: Core Markdown block parser.
+    blockprocessors: Block processors.
+    treeprocessors: Tree processors.
+    inlinepatterns: Inline patterns.
+    postprocessors: Post-processors.
+    serializers: Serializers.
+    util: Utility functions.
+    htmlparser: HTML parser.
+    test_tools: Testing utilities.
+    extensions: Markdown extensions.
+"""
+
+from __future__ import annotations
+
+from .core import Markdown, markdown, markdownFromFile
+from .__meta__ import __version__, __version_info__  # noqa
+
+# For backward compatibility as some extensions expect it...
+from .extensions import Extension  # noqa
+
+__all__ = ['Markdown', 'markdown', 'markdownFromFile']

plugins/markdown_preview/markdown/__main__.py

@@ -0,0 +1,151 @@
+# Python Markdown
+
+# A Python implementation of John Gruber's Markdown.
+
+# Documentation: https://python-markdown.github.io/
+# GitHub: https://github.com/Python-Markdown/markdown/
+# PyPI: https://pypi.org/project/Markdown/
+
+# Started by Manfred Stienstra (http://www.dwerg.net/).
+# Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
+# Currently maintained by Waylan Limberg (https://github.com/waylan),
+# Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
+
+# Copyright 2007-2023 The Python Markdown Project (v. 1.7 and later)
+# Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
+# Copyright 2004 Manfred Stienstra (the original version)
+
+# License: BSD (see LICENSE.md for details).
+
+from __future__ import annotations
+
+import sys
+import optparse
+import codecs
+import warnings
+import markdown
+try:
+    # We use `unsafe_load` because users may need to pass in actual Python
+    # objects. As this is only available from the CLI, the user has much
+    # worse problems if an attacker can use this as an attach vector.
+    from yaml import unsafe_load as yaml_load
+except ImportError:  # pragma: no cover
+    try:
+        # Fall back to PyYAML <5.1
+        from yaml import load as yaml_load
+    except ImportError:
+        # Fall back to JSON
+        from json import load as yaml_load
+
+import logging
+from logging import DEBUG, WARNING, CRITICAL
+
+logger = logging.getLogger('MARKDOWN')
+
+
+def parse_options(args=None, values=None):
+    """
+    Define and parse `optparse` options for command-line usage.
+    """
+    usage = """%prog [options] [INPUTFILE]
+       (STDIN is assumed if no INPUTFILE is given)"""
+    desc = "A Python implementation of John Gruber's Markdown. " \
+           "https://Python-Markdown.github.io/"
+    ver = "%%prog %s" % markdown.__version__
+
+    parser = optparse.OptionParser(usage=usage, description=desc, version=ver)
+    parser.add_option("-f", "--file", dest="filename", default=None,
+                      help="Write output to OUTPUT_FILE. Defaults to STDOUT.",
+                      metavar="OUTPUT_FILE")
+    parser.add_option("-e", "--encoding", dest="encoding",
+                      help="Encoding for input and output files.",)
+    parser.add_option("-o", "--output_format", dest="output_format",
+                      default='xhtml', metavar="OUTPUT_FORMAT",
+                      help="Use output format 'xhtml' (default) or 'html'.")
+    parser.add_option("-n", "--no_lazy_ol", dest="lazy_ol",
+                      action='store_false', default=True,
+                      help="Observe number of first item of ordered lists.")
+    parser.add_option("-x", "--extension", action="append", dest="extensions",
+                      help="Load extension EXTENSION.", metavar="EXTENSION")
+    parser.add_option("-c", "--extension_configs",
+                      dest="configfile", default=None,
+                      help="Read extension configurations from CONFIG_FILE. "
+                      "CONFIG_FILE must be of JSON or YAML format. YAML "
+                      "format requires that a python YAML library be "
+                      "installed. The parsed JSON or YAML must result in a "
+                      "python dictionary which would be accepted by the "
+                      "'extension_configs' keyword on the markdown.Markdown "
+                      "class. The extensions must also be loaded with the "
+                      "`--extension` option.",
+                      metavar="CONFIG_FILE")
+    parser.add_option("-q", "--quiet", default=CRITICAL,
+                      action="store_const", const=CRITICAL+10, dest="verbose",
+                      help="Suppress all warnings.")
+    parser.add_option("-v", "--verbose",
+                      action="store_const", const=WARNING, dest="verbose",
+                      help="Print all warnings.")
+    parser.add_option("--noisy",
+                      action="store_const", const=DEBUG, dest="verbose",
+                      help="Print debug messages.")
+
+    (options, args) = parser.parse_args(args, values)
+
+    if len(args) == 0:
+        input_file = None
+    else:
+        input_file = args[0]
+
+    if not options.extensions:
+        options.extensions = []
+
+    extension_configs = {}
+    if options.configfile:
+        with codecs.open(
+            options.configfile, mode="r", encoding=options.encoding
+        ) as fp:
+            try:
+                extension_configs = yaml_load(fp)
+            except Exception as e:
+                message = "Failed parsing extension config file: %s" % \
+                          options.configfile
+                e.args = (message,) + e.args[1:]
+                raise
+
+    opts = {
+        'input': input_file,
+        'output': options.filename,
+        'extensions': options.extensions,
+        'extension_configs': extension_configs,
+        'encoding': options.encoding,
+        'output_format': options.output_format,
+        'lazy_ol': options.lazy_ol
+    }
+
+    return opts, options.verbose
+
+
+def run():  # pragma: no cover
+    """Run Markdown from the command line."""
+
+    # Parse options and adjust logging level if necessary
+    options, logging_level = parse_options()
+    if not options:
+        sys.exit(2)
+    logger.setLevel(logging_level)
+    console_handler = logging.StreamHandler()
+    logger.addHandler(console_handler)
+    if logging_level <= WARNING:
+        # Ensure deprecation warnings get displayed
+        warnings.filterwarnings('default')
+        logging.captureWarnings(True)
+        warn_logger = logging.getLogger('py.warnings')
+        warn_logger.addHandler(console_handler)
+
+    # Run
+    markdown.markdownFromFile(**options)
+
+
+if __name__ == '__main__':  # pragma: no cover
+    # Support running module as a command line command.
+    #     python -m markdown [options] [args]
+    run()

plugins/markdown_preview/markdown/__meta__.py

@@ -0,0 +1,51 @@
+# Python Markdown
+
+# A Python implementation of John Gruber's Markdown.
+
+# Documentation: https://python-markdown.github.io/
+# GitHub: https://github.com/Python-Markdown/markdown/
+# PyPI: https://pypi.org/project/Markdown/
+
+# Started by Manfred Stienstra (http://www.dwerg.net/).
+# Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
+# Currently maintained by Waylan Limberg (https://github.com/waylan),
+# Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
+
+# Copyright 2007-2023 The Python Markdown Project (v. 1.7 and later)
+# Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
+# Copyright 2004 Manfred Stienstra (the original version)
+
+# License: BSD (see LICENSE.md for details).
+
+# __version_info__ format:
+#     (major, minor, patch, dev/alpha/beta/rc/final, #)
+#     (1, 1, 2, 'dev', 0) => "1.1.2.dev0"
+#     (1, 1, 2, 'alpha', 1) => "1.1.2a1"
+#     (1, 2, 0, 'beta', 2) => "1.2b2"
+#     (1, 2, 0, 'rc', 4) => "1.2rc4"
+#     (1, 2, 0, 'final', 0) => "1.2"
+
+from __future__ import annotations
+
+
+__version_info__ = (3, 5, 1, 'final', 0)
+
+
+def _get_version(version_info):
+    " Returns a PEP 440-compliant version number from `version_info`. "
+    assert len(version_info) == 5
+    assert version_info[3] in ('dev', 'alpha', 'beta', 'rc', 'final')
+
+    parts = 2 if version_info[2] == 0 else 3
+    v = '.'.join(map(str, version_info[:parts]))
+
+    if version_info[3] == 'dev':
+        v += '.dev' + str(version_info[4])
+    elif version_info[3] != 'final':
+        mapping = {'alpha': 'a', 'beta': 'b', 'rc': 'rc'}
+        v += mapping[version_info[3]] + str(version_info[4])
+
+    return v
+
+
+__version__ = _get_version(__version_info__)

plugins/markdown_preview/markdown/blockparser.py

@@ -0,0 +1,160 @@
+# Python Markdown
+
+# A Python implementation of John Gruber's Markdown.
+
+# Documentation: https://python-markdown.github.io/
+# GitHub: https://github.com/Python-Markdown/markdown/
+# PyPI: https://pypi.org/project/Markdown/
+
+# Started by Manfred Stienstra (http://www.dwerg.net/).
+# Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
+# Currently maintained by Waylan Limberg (https://github.com/waylan),
+# Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
+
+# Copyright 2007-2023 The Python Markdown Project (v. 1.7 and later)
+# Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
+# Copyright 2004 Manfred Stienstra (the original version)
+
+# License: BSD (see LICENSE.md for details).
+
+"""
+The block parser handles basic parsing of Markdown blocks.  It doesn't concern
+itself with inline elements such as `**bold**` or `*italics*`, but rather just
+catches blocks, lists, quotes, etc.
+
+The `BlockParser` is made up of a bunch of `BlockProcessors`, each handling a
+different type of block. Extensions may add/replace/remove `BlockProcessors`
+as they need to alter how Markdown blocks are parsed.
+"""
+
+from __future__ import annotations
+
+import xml.etree.ElementTree as etree
+from typing import TYPE_CHECKING, Iterable, Any
+from . import util
+
+if TYPE_CHECKING:  # pragma: no cover
+    from markdown import Markdown
+    from .blockprocessors import BlockProcessor
+
+
+class State(list):
+    """ Track the current and nested state of the parser.
+
+    This utility class is used to track the state of the `BlockParser` and
+    support multiple levels if nesting. It's just a simple API wrapped around
+    a list. Each time a state is set, that state is appended to the end of the
+    list. Each time a state is reset, that state is removed from the end of
+    the list.
+
+    Therefore, each time a state is set for a nested block, that state must be
+    reset when we back out of that level of nesting or the state could be
+    corrupted.
+
+    While all the methods of a list object are available, only the three
+    defined below need be used.
+
+    """
+
+    def set(self, state: Any):
+        """ Set a new state. """
+        self.append(state)
+
+    def reset(self) -> None:
+        """ Step back one step in nested state. """
+        self.pop()
+
+    def isstate(self, state: Any) -> bool:
+        """ Test that top (current) level is of given state. """
+        if len(self):
+            return self[-1] == state
+        else:
+            return False
+
+
+class BlockParser:
+    """ Parse Markdown blocks into an `ElementTree` object.
+
+    A wrapper class that stitches the various `BlockProcessors` together,
+    looping through them and creating an `ElementTree` object.
+
+    """
+
+    def __init__(self, md: Markdown):
+        """ Initialize the block parser.
+
+        Arguments:
+            md: A Markdown instance.
+
+        Attributes:
+            BlockParser.md (Markdown): A Markdown instance.
+            BlockParser.state (State): Tracks the nesting level of current location in document being parsed.
+            BlockParser.blockprocessors (util.Registry): A collection of
+                [`blockprocessors`][markdown.blockprocessors].
+
+        """
+        self.blockprocessors: util.Registry[BlockProcessor] = util.Registry()
+        self.state = State()
+        self.md = md
+
+    def parseDocument(self, lines: Iterable[str]) -> etree.ElementTree:
+        """ Parse a Markdown document into an `ElementTree`.
+
+        Given a list of lines, an `ElementTree` object (not just a parent
+        `Element`) is created and the root element is passed to the parser
+        as the parent. The `ElementTree` object is returned.
+
+        This should only be called on an entire document, not pieces.
+
+        Arguments:
+            lines: A list of lines (strings).
+
+        Returns:
+            An element tree.
+        """
+        # Create an `ElementTree` from the lines
+        self.root = etree.Element(self.md.doc_tag)
+        self.parseChunk(self.root, '\n'.join(lines))
+        return etree.ElementTree(self.root)
+
+    def parseChunk(self, parent: etree.Element, text: str) -> None:
+        """ Parse a chunk of Markdown text and attach to given `etree` node.
+
+        While the `text` argument is generally assumed to contain multiple
+        blocks which will be split on blank lines, it could contain only one
+        block. Generally, this method would be called by extensions when
+        block parsing is required.
+
+        The `parent` `etree` Element passed in is altered in place.
+        Nothing is returned.
+
+        Arguments:
+            parent: The parent element.
+            text: The text to parse.
+
+        """
+        self.parseBlocks(parent, text.split('\n\n'))
+
+    def parseBlocks(self, parent: etree.Element, blocks: list[str]) -> None:
+        """ Process blocks of Markdown text and attach to given `etree` node.
+
+        Given a list of `blocks`, each `blockprocessor` is stepped through
+        until there are no blocks left. While an extension could potentially
+        call this method directly, it's generally expected to be used
+        internally.
+
+        This is a public method as an extension may need to add/alter
+        additional `BlockProcessors` which call this method to recursively
+        parse a nested block.
+
+        Arguments:
+            parent: The parent element.
+            blocks: The blocks of text to parse.
+
+        """
+        while blocks:
+            for processor in self.blockprocessors:
+                if processor.test(parent, blocks[0]):
+                    if processor.run(parent, blocks) is not False:
+                        # run returns True or None
+                        break

plugins/markdown_preview/markdown/blockprocessors.py

@@ -0,0 +1,636 @@
+# Python Markdown
+
+# A Python implementation of John Gruber's Markdown.
+
+# Documentation: https://python-markdown.github.io/
+# GitHub: https://github.com/Python-Markdown/markdown/
+# PyPI: https://pypi.org/project/Markdown/
+
+# Started by Manfred Stienstra (http://www.dwerg.net/).
+# Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
+# Currently maintained by Waylan Limberg (https://github.com/waylan),
+# Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
+
+# Copyright 2007-2023 The Python Markdown Project (v. 1.7 and later)
+# Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
+# Copyright 2004 Manfred Stienstra (the original version)
+
+# License: BSD (see LICENSE.md for details).
+
+"""
+A block processor parses blocks of text and adds new elements to the ElementTree. Blocks of text,
+separated from other text by blank lines, may have a different syntax and produce a differently
+structured tree than other Markdown. Block processors excel at handling code formatting, equation
+layouts, tables, etc.
+"""
+
+from __future__ import annotations
+
+import logging
+import re
+import xml.etree.ElementTree as etree
+from typing import TYPE_CHECKING, Any
+from . import util
+from .blockparser import BlockParser
+
+if TYPE_CHECKING:  # pragma: no cover
+    from markdown import Markdown
+
+logger = logging.getLogger('MARKDOWN')
+
+
+def build_block_parser(md: Markdown, **kwargs: Any) -> BlockParser:
+    """ Build the default block parser used by Markdown. """
+    parser = BlockParser(md)
+    parser.blockprocessors.register(EmptyBlockProcessor(parser), 'empty', 100)
+    parser.blockprocessors.register(ListIndentProcessor(parser), 'indent', 90)
+    parser.blockprocessors.register(CodeBlockProcessor(parser), 'code', 80)
+    parser.blockprocessors.register(HashHeaderProcessor(parser), 'hashheader', 70)
+    parser.blockprocessors.register(SetextHeaderProcessor(parser), 'setextheader', 60)
+    parser.blockprocessors.register(HRProcessor(parser), 'hr', 50)
+    parser.blockprocessors.register(OListProcessor(parser), 'olist', 40)
+    parser.blockprocessors.register(UListProcessor(parser), 'ulist', 30)
+    parser.blockprocessors.register(BlockQuoteProcessor(parser), 'quote', 20)
+    parser.blockprocessors.register(ReferenceProcessor(parser), 'reference', 15)
+    parser.blockprocessors.register(ParagraphProcessor(parser), 'paragraph', 10)
+    return parser
+
+
+class BlockProcessor:
+    """ Base class for block processors.
+
+    Each subclass will provide the methods below to work with the source and
+    tree. Each processor will need to define it's own `test` and `run`
+    methods. The `test` method should return True or False, to indicate
+    whether the current block should be processed by this processor. If the
+    test passes, the parser will call the processors `run` method.
+
+    Attributes:
+        BlockProcessor.parser (BlockParser): The `BlockParser` instance this is attached to.
+        BlockProcessor.tab_length (int): The tab length set on the `Markdown` instance.
+
+    """
+
+    def __init__(self, parser: BlockParser):
+        self.parser = parser
+        self.tab_length = parser.md.tab_length
+
+    def lastChild(self, parent: etree.Element) -> etree.Element | None:
+        """ Return the last child of an `etree` element. """
+        if len(parent):
+            return parent[-1]
+        else:
+            return None
+
+    def detab(self, text: str, length: int | None = None) -> tuple[str, str]:
+        """ Remove a tab from the front of each line of the given text. """
+        if length is None:
+            length = self.tab_length
+        newtext = []
+        lines = text.split('\n')
+        for line in lines:
+            if line.startswith(' ' * length):
+                newtext.append(line[length:])
+            elif not line.strip():
+                newtext.append('')
+            else:
+                break
+        return '\n'.join(newtext), '\n'.join(lines[len(newtext):])
+
+    def looseDetab(self, text: str, level: int = 1) -> str:
+        """ Remove a tab from front of lines but allowing dedented lines. """
+        lines = text.split('\n')
+        for i in range(len(lines)):
+            if lines[i].startswith(' '*self.tab_length*level):
+                lines[i] = lines[i][self.tab_length*level:]
+        return '\n'.join(lines)
+
+    def test(self, parent: etree.Element, block: str) -> bool:
+        """ Test for block type. Must be overridden by subclasses.
+
+        As the parser loops through processors, it will call the `test`
+        method on each to determine if the given block of text is of that
+        type. This method must return a boolean `True` or `False`. The
+        actual method of testing is left to the needs of that particular
+        block type. It could be as simple as `block.startswith(some_string)`
+        or a complex regular expression. As the block type may be different
+        depending on the parent of the block (i.e. inside a list), the parent
+        `etree` element is also provided and may be used as part of the test.
+
+        Keyword arguments:
+            parent: An `etree` element which will be the parent of the block.
+            block: A block of text from the source which has been split at blank lines.
+        """
+        pass  # pragma: no cover
+
+    def run(self, parent: etree.Element, blocks: list[str]) -> bool | None:
+        """ Run processor. Must be overridden by subclasses.
+
+        When the parser determines the appropriate type of a block, the parser
+        will call the corresponding processor's `run` method. This method
+        should parse the individual lines of the block and append them to
+        the `etree`.
+
+        Note that both the `parent` and `etree` keywords are pointers
+        to instances of the objects which should be edited in place. Each
+        processor must make changes to the existing objects as there is no
+        mechanism to return new/different objects to replace them.
+
+        This means that this method should be adding `SubElements` or adding text
+        to the parent, and should remove (`pop`) or add (`insert`) items to
+        the list of blocks.
+
+        If `False` is returned, this will have the same effect as returning `False`
+        from the `test` method.
+
+        Keyword arguments:
+            parent: An `etree` element which is the parent of the current block.
+            blocks: A list of all remaining blocks of the document.
+        """
+        pass  # pragma: no cover
+
+
+class ListIndentProcessor(BlockProcessor):
+    """ Process children of list items.
+
+    Example
+
+        * a list item
+            process this part
+
+            or this part
+
+    """
+
+    ITEM_TYPES = ['li']
+    """ List of tags used for list items. """
+    LIST_TYPES = ['ul', 'ol']
+    """ Types of lists this processor can operate on. """
+
+    def __init__(self, *args):
+        super().__init__(*args)
+        self.INDENT_RE = re.compile(r'^(([ ]{%s})+)' % self.tab_length)
+
+    def test(self, parent, block):
+        return block.startswith(' '*self.tab_length) and \
+            not self.parser.state.isstate('detabbed') and \
+            (parent.tag in self.ITEM_TYPES or
+                (len(parent) and parent[-1] is not None and
+                    (parent[-1].tag in self.LIST_TYPES)))
+
+    def run(self, parent, blocks):
+        block = blocks.pop(0)
+        level, sibling = self.get_level(parent, block)
+        block = self.looseDetab(block, level)
+
+        self.parser.state.set('detabbed')
+        if parent.tag in self.ITEM_TYPES:
+            # It's possible that this parent has a `ul` or `ol` child list
+            # with a member.  If that is the case, then that should be the
+            # parent.  This is intended to catch the edge case of an indented
+            # list whose first member was parsed previous to this point
+            # see `OListProcessor`
+            if len(parent) and parent[-1].tag in self.LIST_TYPES:
+                self.parser.parseBlocks(parent[-1], [block])
+            else:
+                # The parent is already a `li`. Just parse the child block.
+                self.parser.parseBlocks(parent, [block])
+        elif sibling.tag in self.ITEM_TYPES:
+            # The sibling is a `li`. Use it as parent.
+            self.parser.parseBlocks(sibling, [block])
+        elif len(sibling) and sibling[-1].tag in self.ITEM_TYPES:
+            # The parent is a list (`ol` or `ul`) which has children.
+            # Assume the last child `li` is the parent of this block.
+            if sibling[-1].text:
+                # If the parent `li` has text, that text needs to be moved to a `p`
+                # The `p` must be 'inserted' at beginning of list in the event
+                # that other children already exist i.e.; a nested sub-list.
+                p = etree.Element('p')
+                p.text = sibling[-1].text
+                sibling[-1].text = ''
+                sibling[-1].insert(0, p)
+            self.parser.parseChunk(sibling[-1], block)
+        else:
+            self.create_item(sibling, block)
+        self.parser.state.reset()
+
+    def create_item(self, parent: etree.Element, block: str) -> None:
+        """ Create a new `li` and parse the block with it as the parent. """
+        li = etree.SubElement(parent, 'li')
+        self.parser.parseBlocks(li, [block])
+
+    def get_level(self, parent: etree.Element, block: str) -> tuple[int, etree.Element]:
+        """ Get level of indentation based on list level. """
+        # Get indent level
+        m = self.INDENT_RE.match(block)
+        if m:
+            indent_level = len(m.group(1))/self.tab_length
+        else:
+            indent_level = 0
+        if self.parser.state.isstate('list'):
+            # We're in a tight-list - so we already are at correct parent.
+            level = 1
+        else:
+            # We're in a loose-list - so we need to find parent.
+            level = 0
+        # Step through children of tree to find matching indent level.
+        while indent_level > level:
+            child = self.lastChild(parent)
+            if (child is not None and
+               (child.tag in self.LIST_TYPES or child.tag in self.ITEM_TYPES)):
+                if child.tag in self.LIST_TYPES:
+                    level += 1
+                parent = child
+            else:
+                # No more child levels. If we're short of `indent_level`,
+                # we have a code block. So we stop here.
+                break
+        return level, parent
+
+
+class CodeBlockProcessor(BlockProcessor):
+    """ Process code blocks. """
+
+    def test(self, parent, block):
+        return block.startswith(' '*self.tab_length)
+
+    def run(self, parent, blocks):
+        sibling = self.lastChild(parent)
+        block = blocks.pop(0)
+        theRest = ''
+        if (sibling is not None and sibling.tag == "pre" and
+           len(sibling) and sibling[0].tag == "code"):
+            # The previous block was a code block. As blank lines do not start
+            # new code blocks, append this block to the previous, adding back
+            # line breaks removed from the split into a list.
+            code = sibling[0]
+            block, theRest = self.detab(block)
+            code.text = util.AtomicString(
+                '{}\n{}\n'.format(code.text, util.code_escape(block.rstrip()))
+            )
+        else:
+            # This is a new code block. Create the elements and insert text.
+            pre = etree.SubElement(parent, 'pre')
+            code = etree.SubElement(pre, 'code')
+            block, theRest = self.detab(block)
+            code.text = util.AtomicString('%s\n' % util.code_escape(block.rstrip()))
+        if theRest:
+            # This block contained unindented line(s) after the first indented
+            # line. Insert these lines as the first block of the master blocks
+            # list for future processing.
+            blocks.insert(0, theRest)
+
+
+class BlockQuoteProcessor(BlockProcessor):
+    """ Process blockquotes. """
+
+    RE = re.compile(r'(^|\n)[ ]{0,3}>[ ]?(.*)')
+
+    def test(self, parent, block):
+        return bool(self.RE.search(block)) and not util.nearing_recursion_limit()
+
+    def run(self, parent, blocks):
+        block = blocks.pop(0)
+        m = self.RE.search(block)
+        if m:
+            before = block[:m.start()]  # Lines before blockquote
+            # Pass lines before blockquote in recursively for parsing first.
+            self.parser.parseBlocks(parent, [before])
+            # Remove `> ` from beginning of each line.
+            block = '\n'.join(
+                [self.clean(line) for line in block[m.start():].split('\n')]
+            )
+        sibling = self.lastChild(parent)
+        if sibling is not None and sibling.tag == "blockquote":
+            # Previous block was a blockquote so set that as this blocks parent
+            quote = sibling
+        else:
+            # This is a new blockquote. Create a new parent element.
+            quote = etree.SubElement(parent, 'blockquote')
+        # Recursively parse block with blockquote as parent.
+        # change parser state so blockquotes embedded in lists use `p` tags
+        self.parser.state.set('blockquote')
+        self.parser.parseChunk(quote, block)
+        self.parser.state.reset()
+
+    def clean(self, line: str) -> str:
+        """ Remove `>` from beginning of a line. """
+        m = self.RE.match(line)
+        if line.strip() == ">":
+            return ""
+        elif m:
+            return m.group(2)
+        else:
+            return line
+
+
+class OListProcessor(BlockProcessor):
+    """ Process ordered list blocks. """
+
+    TAG: str = 'ol'
+    """ The tag used for the the wrapping element. """
+    STARTSWITH: str = '1'
+    """
+    The integer (as a string ) with which the list starts. For example, if a list is initialized as
+    `3. Item`, then the `ol` tag will be assigned an HTML attribute of `starts="3"`. Default: `"1"`.
+    """
+    LAZY_OL: bool = True
+    """ Ignore `STARTSWITH` if `True`. """
+    SIBLING_TAGS: list[str] = ['ol', 'ul']
+    """
+    Markdown does not require the type of a new list item match the previous list item type.
+    This is the list of types which can be mixed.
+    """
+
+    def __init__(self, parser: BlockParser):
+        super().__init__(parser)
+        # Detect an item (`1. item`). `group(1)` contains contents of item.
+        self.RE = re.compile(r'^[ ]{0,%d}\d+\.[ ]+(.*)' % (self.tab_length - 1))
+        # Detect items on secondary lines. they can be of either list type.
+        self.CHILD_RE = re.compile(r'^[ ]{0,%d}((\d+\.)|[*+-])[ ]+(.*)' %
+                                   (self.tab_length - 1))
+        # Detect indented (nested) items of either type
+        self.INDENT_RE = re.compile(r'^[ ]{%d,%d}((\d+\.)|[*+-])[ ]+.*' %
+                                    (self.tab_length, self.tab_length * 2 - 1))
+
+    def test(self, parent, block):
+        return bool(self.RE.match(block))
+
+    def run(self, parent, blocks):
+        # Check for multiple items in one block.
+        items = self.get_items(blocks.pop(0))
+        sibling = self.lastChild(parent)
+
+        if sibling is not None and sibling.tag in self.SIBLING_TAGS:
+            # Previous block was a list item, so set that as parent
+            lst = sibling
+            # make sure previous item is in a `p` - if the item has text,
+            # then it isn't in a `p`
+            if lst[-1].text:
+                # since it's possible there are other children for this
+                # sibling, we can't just `SubElement` the `p`, we need to
+                # insert it as the first item.
+                p = etree.Element('p')
+                p.text = lst[-1].text
+                lst[-1].text = ''
+                lst[-1].insert(0, p)
+            # if the last item has a tail, then the tail needs to be put in a `p`
+            # likely only when a header is not followed by a blank line
+            lch = self.lastChild(lst[-1])
+            if lch is not None and lch.tail:
+                p = etree.SubElement(lst[-1], 'p')
+                p.text = lch.tail.lstrip()
+                lch.tail = ''
+
+            # parse first block differently as it gets wrapped in a `p`.
+            li = etree.SubElement(lst, 'li')
+            self.parser.state.set('looselist')
+            firstitem = items.pop(0)
+            self.parser.parseBlocks(li, [firstitem])
+            self.parser.state.reset()
+        elif parent.tag in ['ol', 'ul']:
+            # this catches the edge case of a multi-item indented list whose
+            # first item is in a blank parent-list item:
+            #     * * subitem1
+            #         * subitem2
+            # see also `ListIndentProcessor`
+            lst = parent
+        else:
+            # This is a new list so create parent with appropriate tag.
+            lst = etree.SubElement(parent, self.TAG)
+            # Check if a custom start integer is set
+            if not self.LAZY_OL and self.STARTSWITH != '1':
+                lst.attrib['start'] = self.STARTSWITH
+
+        self.parser.state.set('list')
+        # Loop through items in block, recursively parsing each with the
+        # appropriate parent.
+        for item in items:
+            if item.startswith(' '*self.tab_length):
+                # Item is indented. Parse with last item as parent
+                self.parser.parseBlocks(lst[-1], [item])
+            else:
+                # New item. Create `li` and parse with it as parent
+                li = etree.SubElement(lst, 'li')
+                self.parser.parseBlocks(li, [item])
+        self.parser.state.reset()
+
+    def get_items(self, block: str) -> list[str]:
+        """ Break a block into list items. """
+        items = []
+        for line in block.split('\n'):
+            m = self.CHILD_RE.match(line)
+            if m:
+                # This is a new list item
+                # Check first item for the start index
+                if not items and self.TAG == 'ol':
+                    # Detect the integer value of first list item
+                    INTEGER_RE = re.compile(r'(\d+)')
+                    self.STARTSWITH = INTEGER_RE.match(m.group(1)).group()
+                # Append to the list
+                items.append(m.group(3))
+            elif self.INDENT_RE.match(line):
+                # This is an indented (possibly nested) item.
+                if items[-1].startswith(' '*self.tab_length):
+                    # Previous item was indented. Append to that item.
+                    items[-1] = '{}\n{}'.format(items[-1], line)
+                else:
+                    items.append(line)
+            else:
+                # This is another line of previous item. Append to that item.
+                items[-1] = '{}\n{}'.format(items[-1], line)
+        return items
+
+
+class UListProcessor(OListProcessor):
+    """ Process unordered list blocks. """
+
+    TAG: str = 'ul'
+    """ The tag used for the the wrapping element. """
+
+    def __init__(self, parser: BlockParser):
+        super().__init__(parser)
+        # Detect an item (`1. item`). `group(1)` contains contents of item.
+        self.RE = re.compile(r'^[ ]{0,%d}[*+-][ ]+(.*)' % (self.tab_length - 1))
+
+
+class HashHeaderProcessor(BlockProcessor):
+    """ Process Hash Headers. """
+
+    # Detect a header at start of any line in block
+    RE = re.compile(r'(?:^|\n)(?P<level>#{1,6})(?P<header>(?:\\.|[^\\])*?)#*(?:\n|$)')
+
+    def test(self, parent, block):
+        return bool(self.RE.search(block))
+
+    def run(self, parent, blocks):
+        block = blocks.pop(0)
+        m = self.RE.search(block)
+        if m:
+            before = block[:m.start()]  # All lines before header
+            after = block[m.end():]     # All lines after header
+            if before:
+                # As the header was not the first line of the block and the
+                # lines before the header must be parsed first,
+                # recursively parse this lines as a block.
+                self.parser.parseBlocks(parent, [before])
+            # Create header using named groups from RE
+            h = etree.SubElement(parent, 'h%d' % len(m.group('level')))
+            h.text = m.group('header').strip()
+            if after:
+                # Insert remaining lines as first block for future parsing.
+                blocks.insert(0, after)
+        else:  # pragma: no cover
+            # This should never happen, but just in case...
+            logger.warn("We've got a problem header: %r" % block)
+
+
+class SetextHeaderProcessor(BlockProcessor):
+    """ Process Setext-style Headers. """
+
+    # Detect Setext-style header. Must be first 2 lines of block.
+    RE = re.compile(r'^.*?\n[=-]+[ ]*(\n|$)', re.MULTILINE)
+
+    def test(self, parent, block):
+        return bool(self.RE.match(block))
+
+    def run(self, parent, blocks):
+        lines = blocks.pop(0).split('\n')
+        # Determine level. `=` is 1 and `-` is 2.
+        if lines[1].startswith('='):
+            level = 1
+        else:
+            level = 2
+        h = etree.SubElement(parent, 'h%d' % level)
+        h.text = lines[0].strip()
+        if len(lines) > 2:
+            # Block contains additional lines. Add to  master blocks for later.
+            blocks.insert(0, '\n'.join(lines[2:]))
+
+
+class HRProcessor(BlockProcessor):
+    """ Process Horizontal Rules. """
+
+    # Python's `re` module doesn't officially support atomic grouping. However you can fake it.
+    # See https://stackoverflow.com/a/13577411/866026
+    RE = r'^[ ]{0,3}(?=(?P<atomicgroup>(-+[ ]{0,2}){3,}|(_+[ ]{0,2}){3,}|(\*+[ ]{0,2}){3,}))(?P=atomicgroup)[ ]*$'
+    # Detect hr on any line of a block.
+    SEARCH_RE = re.compile(RE, re.MULTILINE)
+
+    def test(self, parent, block):
+        m = self.SEARCH_RE.search(block)
+        if m:
+            # Save match object on class instance so we can use it later.
+            self.match = m
+            return True
+        return False
+
+    def run(self, parent, blocks):
+        block = blocks.pop(0)
+        match = self.match
+        # Check for lines in block before `hr`.
+        prelines = block[:match.start()].rstrip('\n')
+        if prelines:
+            # Recursively parse lines before `hr` so they get parsed first.
+            self.parser.parseBlocks(parent, [prelines])
+        # create hr
+        etree.SubElement(parent, 'hr')
+        # check for lines in block after `hr`.
+        postlines = block[match.end():].lstrip('\n')
+        if postlines:
+            # Add lines after `hr` to master blocks for later parsing.
+            blocks.insert(0, postlines)
+
+
+class EmptyBlockProcessor(BlockProcessor):
+    """ Process blocks that are empty or start with an empty line. """
+
+    def test(self, parent, block):
+        return not block or block.startswith('\n')
+
+    def run(self, parent, blocks):
+        block = blocks.pop(0)
+        filler = '\n\n'
+        if block:
+            # Starts with empty line
+            # Only replace a single line.
+            filler = '\n'
+            # Save the rest for later.
+            theRest = block[1:]
+            if theRest:
+                # Add remaining lines to master blocks for later.
+                blocks.insert(0, theRest)
+        sibling = self.lastChild(parent)
+        if (sibling is not None and sibling.tag == 'pre' and
+           len(sibling) and sibling[0].tag == 'code'):
+            # Last block is a code block. Append to preserve whitespace.
+            sibling[0].text = util.AtomicString(
+                '{}{}'.format(sibling[0].text, filler)
+            )
+
+
+class ReferenceProcessor(BlockProcessor):
+    """ Process link references. """
+    RE = re.compile(
+        r'^[ ]{0,3}\[([^\[\]]*)\]:[ ]*\n?[ ]*([^\s]+)[ ]*(?:\n[ ]*)?((["\'])(.*)\4[ ]*|\((.*)\)[ ]*)?$', re.MULTILINE
+    )
+
+    def test(self, parent, block):
+        return True
+
+    def run(self, parent, blocks):
+        block = blocks.pop(0)
+        m = self.RE.search(block)
+        if m:
+            id = m.group(1).strip().lower()
+            link = m.group(2).lstrip('<').rstrip('>')
+            title = m.group(5) or m.group(6)
+            self.parser.md.references[id] = (link, title)
+            if block[m.end():].strip():
+                # Add any content after match back to blocks as separate block
+                blocks.insert(0, block[m.end():].lstrip('\n'))
+            if block[:m.start()].strip():
+                # Add any content before match back to blocks as separate block
+                blocks.insert(0, block[:m.start()].rstrip('\n'))
+            return True
+        # No match. Restore block.
+        blocks.insert(0, block)
+        return False
+
+
+class ParagraphProcessor(BlockProcessor):
+    """ Process Paragraph blocks. """
+
+    def test(self, parent, block):
+        return True
+
+    def run(self, parent, blocks):
+        block = blocks.pop(0)
+        if block.strip():
+            # Not a blank block. Add to parent, otherwise throw it away.
+            if self.parser.state.isstate('list'):
+                # The parent is a tight-list.
+                #
+                # Check for any children. This will likely only happen in a
+                # tight-list when a header isn't followed by a blank line.
+                # For example:
+                #
+                #     * # Header
+                #     Line 2 of list item - not part of header.
+                sibling = self.lastChild(parent)
+                if sibling is not None:
+                    # Insert after sibling.
+                    if sibling.tail:
+                        sibling.tail = '{}\n{}'.format(sibling.tail, block)
+                    else:
+                        sibling.tail = '\n%s' % block
+                else:
+                    # Append to parent.text
+                    if parent.text:
+                        parent.text = '{}\n{}'.format(parent.text, block)
+                    else:
+                        parent.text = block.lstrip()
+            else:
+                # Create a regular paragraph
+                p = etree.SubElement(parent, 'p')
+                p.text = block.lstrip()

plugins/markdown_preview/markdown/core.py

@@ -0,0 +1,510 @@
+# Python Markdown
+
+# A Python implementation of John Gruber's Markdown.
+
+# Documentation: https://python-markdown.github.io/
+# GitHub: https://github.com/Python-Markdown/markdown/
+# PyPI: https://pypi.org/project/Markdown/
+
+# Started by Manfred Stienstra (http://www.dwerg.net/).
+# Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
+# Currently maintained by Waylan Limberg (https://github.com/waylan),
+# Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
+
+# Copyright 2007-2023 The Python Markdown Project (v. 1.7 and later)
+# Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
+# Copyright 2004 Manfred Stienstra (the original version)
+
+# License: BSD (see LICENSE.md for details).
+
+from __future__ import annotations
+
+import codecs
+import sys
+import logging
+import importlib
+from typing import TYPE_CHECKING, Any, Callable, ClassVar, Mapping, Sequence, TextIO
+from . import util
+from .preprocessors import build_preprocessors
+from .blockprocessors import build_block_parser
+from .treeprocessors import build_treeprocessors
+from .inlinepatterns import build_inlinepatterns
+from .postprocessors import build_postprocessors
+from .extensions import Extension
+from .serializers import to_html_string, to_xhtml_string
+from .util import BLOCK_LEVEL_ELEMENTS
+
+if TYPE_CHECKING:  # pragma: no cover
+    from xml.etree.ElementTree import Element
+
+__all__ = ['Markdown', 'markdown', 'markdownFromFile']
+
+
+logger = logging.getLogger('MARKDOWN')
+
+
+class Markdown:
+    """
+    A parser which converts Markdown to HTML.
+
+    Attributes:
+        Markdown.tab_length (int): The number of spaces which correspond to a single tab. Default: `4`.
+        Markdown.ESCAPED_CHARS (list[str]): List of characters which get the backslash escape treatment.
+        Markdown.block_level_elements (list[str]): List of HTML tags which get treated as block-level elements.
+            See [`markdown.util.BLOCK_LEVEL_ELEMENTS`][] for the full list of elements.
+        Markdown.registeredExtensions (list[Extension]): List of extensions which have called
+            [`registerExtension`][markdown.Markdown.registerExtension] during setup.
+        Markdown.doc_tag (str): Element used to wrap document. Default: `div`.
+        Markdown.stripTopLevelTags (bool): Indicates whether the `doc_tag` should be removed. Default: 'True'.
+        Markdown.references (dict[str, tuple[str, str]]): A mapping of link references found in a parsed document
+             where the key is the reference name and the value is a tuple of the URL and title.
+        Markdown.htmlStash (util.HtmlStash): The instance of the `HtmlStash` used by an instance of this class.
+        Markdown.output_formats (dict[str, Callable[xml.etree.ElementTree.Element]]): A mapping of known output
+             formats by name and their respective serializers. Each serializer must be a callable which accepts an
+            [`Element`][xml.etree.ElementTree.Element] and returns a `str`.
+        Markdown.output_format (str): The output format set by
+            [`set_output_format`][markdown.Markdown.set_output_format].
+        Markdown.serializer (Callable[xml.etree.ElementTree.Element]): The serializer set by
+            [`set_output_format`][markdown.Markdown.set_output_format].
+        Markdown.preprocessors (util.Registry): A collection of [`preprocessors`][markdown.preprocessors].
+        Markdown.parser (blockparser.BlockParser): A collection of [`blockprocessors`][markdown.blockprocessors].
+        Markdown.inlinePatterns (util.Registry): A collection of [`inlinepatterns`][markdown.inlinepatterns].
+        Markdown.treeprocessors (util.Registry): A collection of [`treeprocessors`][markdown.treeprocessors].
+        Markdown.postprocessors (util.Registry): A collection of [`postprocessors`][markdown.postprocessors].
+
+    """
+
+    doc_tag = "div"     # Element used to wrap document - later removed
+
+    output_formats: ClassVar[dict[str, Callable[[Element], str]]] = {
+        'html':   to_html_string,
+        'xhtml':  to_xhtml_string,
+    }
+    """
+    A mapping of known output formats by name and their respective serializers. Each serializer must be a
+    callable which accepts an [`Element`][xml.etree.ElementTree.Element] and returns a `str`.
+    """
+
+    def __init__(self, **kwargs):
+        """
+        Creates a new Markdown instance.
+
+        Keyword Arguments:
+            extensions (list[Extension | str]): A list of extensions.
+
+                If an item is an instance of a subclass of [`markdown.extensions.Extension`][],
+                the instance will be used as-is. If an item is of type `str`, it is passed
+                to [`build_extension`][markdown.Markdown.build_extension] with its corresponding
+                `extension_configs` and the returned instance  of [`markdown.extensions.Extension`][]
+                is used.
+            extension_configs (dict[str, dict[str, Any]]): Configuration settings for extensions.
+            output_format (str): Format of output. Supported formats are:
+
+                * `xhtml`: Outputs XHTML style tags. Default.
+                * `html`: Outputs HTML style tags.
+            tab_length (int): Length of tabs in the source. Default: `4`
+
+        """
+
+        self.tab_length: int = kwargs.get('tab_length', 4)
+
+        self.ESCAPED_CHARS: list[str] = [
+            '\\', '`', '*', '_', '{', '}', '[', ']', '(', ')', '>', '#', '+', '-', '.', '!'
+        ]
+        """ List of characters which get the backslash escape treatment. """
+
+        self.block_level_elements: list[str] = BLOCK_LEVEL_ELEMENTS.copy()
+
+        self.registeredExtensions: list[Extension] = []
+        self.docType = ""  # TODO: Maybe delete this. It does not appear to be used anymore.
+        self.stripTopLevelTags: bool = True
+
+        self.build_parser()
+
+        self.references: dict[str, tuple[str, str]] = {}
+        self.htmlStash: util.HtmlStash = util.HtmlStash()
+        self.registerExtensions(extensions=kwargs.get('extensions', []),
+                                configs=kwargs.get('extension_configs', {}))
+        self.set_output_format(kwargs.get('output_format', 'xhtml'))
+        self.reset()
+
+    def build_parser(self) -> Markdown:
+        """
+        Build the parser from the various parts.
+
+        Assigns a value to each of the following attributes on the class instance:
+
+        * **`Markdown.preprocessors`** ([`Registry`][markdown.util.Registry]) -- A collection of
+          [`preprocessors`][markdown.preprocessors].
+        * **`Markdown.parser`** ([`BlockParser`][markdown.blockparser.BlockParser]) -- A collection of
+          [`blockprocessors`][markdown.blockprocessors].
+        * **`Markdown.inlinePatterns`** ([`Registry`][markdown.util.Registry]) -- A collection of
+          [`inlinepatterns`][markdown.inlinepatterns].
+        * **`Markdown.treeprocessors`** ([`Registry`][markdown.util.Registry]) -- A collection of
+          [`treeprocessors`][markdown.treeprocessors].
+        * **`Markdown.postprocessors`** ([`Registry`][markdown.util.Registry]) -- A collection of
+          [`postprocessors`][markdown.postprocessors].
+
+        This method could be redefined in a subclass to build a custom parser which is made up of a different
+        combination of processors and patterns.
+
+        """
+        self.preprocessors = build_preprocessors(self)
+        self.parser = build_block_parser(self)
+        self.inlinePatterns = build_inlinepatterns(self)
+        self.treeprocessors = build_treeprocessors(self)
+        self.postprocessors = build_postprocessors(self)
+        return self
+
+    def registerExtensions(
+        self,
+        extensions: Sequence[Extension | str],
+        configs: Mapping[str, Mapping[str, Any]]
+    ) -> Markdown:
+        """
+        Load a list of extensions into an instance of the `Markdown` class.
+
+        Arguments:
+            extensions (list[Extension | str]): A list of extensions.
+
+                If an item is an instance of a subclass of [`markdown.extensions.Extension`][],
+                the instance will be used as-is. If an item is of type `str`, it is passed
+                to [`build_extension`][markdown.Markdown.build_extension] with its corresponding `configs` and the
+                returned instance  of [`markdown.extensions.Extension`][] is used.
+            configs (dict[str, dict[str, Any]]): Configuration settings for extensions.
+
+        """
+        for ext in extensions:
+            if isinstance(ext, str):
+                ext = self.build_extension(ext, configs.get(ext, {}))
+            if isinstance(ext, Extension):
+                ext.extendMarkdown(self)
+                logger.debug(
+                    'Successfully loaded extension "%s.%s".'
+                    % (ext.__class__.__module__, ext.__class__.__name__)
+                )
+            elif ext is not None:
+                raise TypeError(
+                    'Extension "{}.{}" must be of type: "{}.{}"'.format(
+                        ext.__class__.__module__, ext.__class__.__name__,
+                        Extension.__module__, Extension.__name__
+                    )
+                )
+        return self
+
+    def build_extension(self, ext_name: str, configs: Mapping[str, Any]) -> Extension:
+        """
+        Build extension from a string name, then return an instance using the given `configs`.
+
+        Arguments:
+            ext_name: Name of extension as a string.
+            configs: Configuration settings for extension.
+
+        Returns:
+            An instance of the extension with the given configuration settings.
+
+        First attempt to load an entry point. The string name must be registered as an entry point in the
+        `markdown.extensions` group which points to a subclass of the [`markdown.extensions.Extension`][] class.
+        If multiple distributions have registered the same name, the first one found is returned.
+
+        If no entry point is found, assume dot notation (`path.to.module:ClassName`). Load the specified class and
+        return an instance. If no class is specified, import the module and call a `makeExtension` function and return
+        the [`markdown.extensions.Extension`][] instance returned by that function.
+        """
+        configs = dict(configs)
+
+        entry_points = [ep for ep in util.get_installed_extensions() if ep.name == ext_name]
+        if entry_points:
+            ext = entry_points[0].load()
+            return ext(**configs)
+
+        # Get class name (if provided): `path.to.module:ClassName`
+        ext_name, class_name = ext_name.split(':', 1) if ':' in ext_name else (ext_name, '')
+
+        try:
+            module = importlib.import_module(ext_name)
+            logger.debug(
+                'Successfully imported extension module "%s".' % ext_name
+            )
+        except ImportError as e:
+            message = 'Failed loading extension "%s".' % ext_name
+            e.args = (message,) + e.args[1:]
+            raise
+
+        if class_name:
+            # Load given class name from module.
+            return getattr(module, class_name)(**configs)
+        else:
+            # Expect  `makeExtension()` function to return a class.
+            try:
+                return module.makeExtension(**configs)
+            except AttributeError as e:
+                message = e.args[0]
+                message = "Failed to initiate extension " \
+                          "'%s': %s" % (ext_name, message)
+                e.args = (message,) + e.args[1:]
+                raise
+
+    def registerExtension(self, extension: Extension) -> Markdown:
+        """
+        Register an extension as having a resettable state.
+
+        Arguments:
+            extension: An instance of the extension to register.
+
+        This should get called once by an extension during setup. A "registered" extension's
+        `reset` method is called by [`Markdown.reset()`][markdown.Markdown.reset]. Not all extensions have or need a
+        resettable state, and so it should not be assumed that all extensions are "registered."
+
+        """
+        self.registeredExtensions.append(extension)
+        return self
+
+    def reset(self) -> Markdown:
+        """
+        Resets all state variables to prepare the parser instance for new input.
+
+        Called once upon creation of a class instance. Should be called manually between calls
+        to [`Markdown.convert`][markdown.Markdown.convert].
+        """
+        self.htmlStash.reset()
+        self.references.clear()
+
+        for extension in self.registeredExtensions:
+            if hasattr(extension, 'reset'):
+                extension.reset()
+
+        return self
+
+    def set_output_format(self, format: str) -> Markdown:
+        """
+        Set the output format for the class instance.
+
+        Arguments:
+            format: Must be a known value in `Markdown.output_formats`.
+
+        """
+        self.output_format = format.lower().rstrip('145')  # ignore number
+        try:
+            self.serializer = self.output_formats[self.output_format]
+        except KeyError as e:
+            valid_formats = list(self.output_formats.keys())
+            valid_formats.sort()
+            message = 'Invalid Output Format: "%s". Use one of %s.' \
+                % (self.output_format,
+                   '"' + '", "'.join(valid_formats) + '"')
+            e.args = (message,) + e.args[1:]
+            raise
+        return self
+
+    # Note: the `tag` argument is type annotated `Any` as ElementTree uses many various objects as tags.
+    # As there is no standardization in ElementTree, the type of a given tag is unpredictable.
+    def is_block_level(self, tag: Any) -> bool:
+        """
+        Check if the given `tag` is a block level HTML tag.
+
+        Returns `True` for any string listed in `Markdown.block_level_elements`. A `tag` which is
+        not a string always returns `False`.
+
+        """
+        if isinstance(tag, str):
+            return tag.lower().rstrip('/') in self.block_level_elements
+        # Some ElementTree tags are not strings, so return False.
+        return False
+
+    def convert(self, source: str) -> str:
+        """
+        Convert a Markdown string to a string in the specified output format.
+
+        Arguments:
+            source: Markdown formatted text as Unicode or ASCII string.
+
+        Returns:
+            A string in the specified output format.
+
+        Markdown parsing takes place in five steps:
+
+        1. A bunch of [`preprocessors`][markdown.preprocessors] munge the input text.
+        2. A [`BlockParser`][markdown.blockparser.BlockParser] parses the high-level structural elements of the
+           pre-processed text into an [`ElementTree`][xml.etree.ElementTree.ElementTree] object.
+        3. A bunch of [`treeprocessors`][markdown.treeprocessors] are run against the
+           [`ElementTree`][xml.etree.ElementTree.ElementTree] object. One such `treeprocessor`
+           ([`markdown.treeprocessors.InlineProcessor`][]) runs [`inlinepatterns`][markdown.inlinepatterns]
+           against the [`ElementTree`][xml.etree.ElementTree.ElementTree] object, parsing inline markup.
+        4. Some [`postprocessors`][markdown.postprocessors] are run against the text after the
+           [`ElementTree`][xml.etree.ElementTree.ElementTree] object has been serialized into text.
+        5. The output is returned as a string.
+
+        """
+
+        # Fix up the source text
+        if not source.strip():
+            return ''  # a blank Unicode string
+
+        try:
+            source = str(source)
+        except UnicodeDecodeError as e:  # pragma: no cover
+            # Customize error message while maintaining original traceback
+            e.reason += '. -- Note: Markdown only accepts Unicode input!'
+            raise
+
+        # Split into lines and run the line preprocessors.
+        self.lines = source.split("\n")
+        for prep in self.preprocessors:
+            self.lines = prep.run(self.lines)
+
+        # Parse the high-level elements.
+        root = self.parser.parseDocument(self.lines).getroot()
+
+        # Run the tree-processors
+        for treeprocessor in self.treeprocessors:
+            newRoot = treeprocessor.run(root)
+            if newRoot is not None:
+                root = newRoot
+
+        # Serialize _properly_.  Strip top-level tags.
+        output = self.serializer(root)
+        if self.stripTopLevelTags:
+            try:
+                start = output.index(
+                    '<%s>' % self.doc_tag) + len(self.doc_tag) + 2
+                end = output.rindex('</%s>' % self.doc_tag)
+                output = output[start:end].strip()
+            except ValueError as e:  # pragma: no cover
+                if output.strip().endswith('<%s />' % self.doc_tag):
+                    # We have an empty document
+                    output = ''
+                else:
+                    # We have a serious problem
+                    raise ValueError('Markdown failed to strip top-level '
+                                     'tags. Document=%r' % output.strip()) from e
+
+        # Run the text post-processors
+        for pp in self.postprocessors:
+            output = pp.run(output)
+
+        return output.strip()
+
+    def convertFile(
+        self,
+        input: str | TextIO | None = None,
+        output: str | TextIO | None = None,
+        encoding: str | None = None,
+    ) -> Markdown:
+        """
+        Converts a Markdown file and returns the HTML as a Unicode string.
+
+        Decodes the file using the provided encoding (defaults to `utf-8`),
+        passes the file content to markdown, and outputs the HTML to either
+        the provided stream or the file with provided name, using the same
+        encoding as the source file. The
+        [`xmlcharrefreplace`](https://docs.python.org/3/library/codecs.html#error-handlers)
+        error handler is used when encoding the output.
+
+        **Note:** This is the only place that decoding and encoding of Unicode
+        takes place in Python-Markdown.  (All other code is Unicode-in /
+        Unicode-out.)
+
+        Arguments:
+            input: File object or path. Reads from `stdin` if `None`.
+            output: File object or path. Writes to `stdout` if `None`.
+            encoding: Encoding of input and output files. Defaults to `utf-8`.
+
+        """
+
+        encoding = encoding or "utf-8"
+
+        # Read the source
+        if input:
+            if isinstance(input, str):
+                input_file = codecs.open(input, mode="r", encoding=encoding)
+            else:
+                input_file = codecs.getreader(encoding)(input)
+            text = input_file.read()
+            input_file.close()
+        else:
+            text = sys.stdin.read()
+            if not isinstance(text, str):  # pragma: no cover
+                text = text.decode(encoding)
+
+        text = text.lstrip('\ufeff')  # remove the byte-order mark
+
+        # Convert
+        html = self.convert(text)
+
+        # Write to file or stdout
+        if output:
+            if isinstance(output, str):
+                output_file = codecs.open(output, "w",
+                                          encoding=encoding,
+                                          errors="xmlcharrefreplace")
+                output_file.write(html)
+                output_file.close()
+            else:
+                writer = codecs.getwriter(encoding)
+                output_file = writer(output, errors="xmlcharrefreplace")
+                output_file.write(html)
+                # Don't close here. User may want to write more.
+        else:
+            # Encode manually and write bytes to stdout.
+            html = html.encode(encoding, "xmlcharrefreplace")
+            try:
+                # Write bytes directly to buffer (Python 3).
+                sys.stdout.buffer.write(html)
+            except AttributeError:  # pragma: no cover
+                # Probably Python 2, which works with bytes by default.
+                sys.stdout.write(html)
+
+        return self
+
+
+"""
+EXPORTED FUNCTIONS
+=============================================================================
+
+Those are the two functions we really mean to export: `markdown()` and
+`markdownFromFile()`.
+"""
+
+
+def markdown(text: str, **kwargs: Any) -> str:
+    """
+    Convert a markdown string to HTML and return HTML as a Unicode string.
+
+    This is a shortcut function for [`Markdown`][markdown.Markdown] class to cover the most
+    basic use case.  It initializes an instance of [`Markdown`][markdown.Markdown], loads the
+    necessary extensions and runs the parser on the given text.
+
+    Arguments:
+        text: Markdown formatted text as Unicode or ASCII string.
+
+    Keyword arguments:
+        **kwargs: Any arguments accepted by the Markdown class.
+
+    Returns:
+        A string in the specified output format.
+
+    """
+    md = Markdown(**kwargs)
+    return md.convert(text)
+
+
+def markdownFromFile(**kwargs: Any):
+    """
+    Read Markdown text from a file and write output to a file or a stream.
+
+    This is a shortcut function which initializes an instance of [`Markdown`][markdown.Markdown],
+    and calls the [`convertFile`][markdown.Markdown.convertFile] method rather than
+    [`convert`][markdown.Markdown.convert].
+
+    Keyword arguments:
+        input (str | TextIO): A file name or readable object.
+        output (str | TextIO): A file name or writable object.
+        encoding (str): Encoding of input and output.
+        **kwargs: Any arguments accepted by the `Markdown` class.
+
+    """
+    md = Markdown(**kwargs)
+    md.convertFile(kwargs.get('input', None),
+                   kwargs.get('output', None),
+                   kwargs.get('encoding', None))

plugins/markdown_preview/markdown/extensions/__init__.py

@@ -0,0 +1,145 @@
+# Python Markdown
+
+# A Python implementation of John Gruber's Markdown.
+
+# Documentation: https://python-markdown.github.io/
+# GitHub: https://github.com/Python-Markdown/markdown/
+# PyPI: https://pypi.org/project/Markdown/
+
+# Started by Manfred Stienstra (http://www.dwerg.net/).
+# Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
+# Currently maintained by Waylan Limberg (https://github.com/waylan),
+# Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
+
+# Copyright 2007-2023 The Python Markdown Project (v. 1.7 and later)
+# Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
+# Copyright 2004 Manfred Stienstra (the original version)
+
+# License: BSD (see LICENSE.md for details).
+
+"""
+Markdown accepts an [`Extension`][markdown.extensions.Extension] instance for each extension. Therefore, each extension
+must to define a class that extends [`Extension`][markdown.extensions.Extension] and over-rides the
+[`extendMarkdown`][markdown.extensions.Extension.extendMarkdown] method. Within this class one can manage configuration
+options for their extension and attach the various processors and patterns which make up an extension to the
+[`Markdown`][markdown.Markdown] instance.
+"""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Any, Mapping, Sequence
+from ..util import parseBoolValue
+
+if TYPE_CHECKING:  # pragma: no cover
+    from markdown import Markdown
+
+
+class Extension:
+    """ Base class for extensions to subclass. """
+
+    config: Mapping[str, list] = {}
+    """
+    Default configuration for an extension.
+
+    This attribute is to be defined in a subclass and must be of the following format:
+
+    ``` python
+    config = {
+        'key': ['value', 'description']
+    }
+    ```
+
+    Note that [`setConfig`][markdown.extensions.Extension.setConfig] will raise a [`KeyError`][]
+    if a default is not set for each option.
+    """
+
+    def __init__(self, **kwargs):
+        """ Initiate Extension and set up configs. """
+        self.setConfigs(kwargs)
+
+    def getConfig(self, key: str, default: Any = '') -> Any:
+        """
+        Return a single configuration option value.
+
+        Arguments:
+            key: The configuration option name.
+            default: Default value to return if key is not set.
+
+        Returns:
+            Value of stored configuration option.
+        """
+        if key in self.config:
+            return self.config[key][0]
+        else:
+            return default
+
+    def getConfigs(self) -> dict[str, Any]:
+        """
+        Return all configuration options.
+
+        Returns:
+            All configuration options.
+        """
+        return {key: self.getConfig(key) for key in self.config.keys()}
+
+    def getConfigInfo(self) -> list[tuple[str, str]]:
+        """
+        Return descriptions of all configuration options.
+
+        Returns:
+            All descriptions of configuration options.
+        """
+        return [(key, self.config[key][1]) for key in self.config.keys()]
+
+    def setConfig(self, key: str, value: Any) -> None:
+        """
+        Set a configuration option.
+
+        If the corresponding default value set in [`config`][markdown.extensions.Extension.config]
+        is a `bool` value or `None`, then `value` is passed through
+        [`parseBoolValue`][markdown.util.parseBoolValue] before being stored.
+
+        Arguments:
+            key: Name of configuration option to set.
+            value: Value to assign to option.
+
+        Raises:
+            KeyError: If `key` is not known.
+        """
+        if isinstance(self.config[key][0], bool):
+            value = parseBoolValue(value)
+        if self.config[key][0] is None:
+            value = parseBoolValue(value, preserve_none=True)
+        self.config[key][0] = value
+
+    def setConfigs(self, items: Mapping[str, Any] | Sequence[tuple[str, Any]]):
+        """
+        Loop through a collection of configuration options, passing each to
+        [`setConfig`][markdown.extensions.Extension.setConfig].
+
+        Arguments:
+            items: Collection of configuration options.
+
+        Raises:
+            KeyError: for any unknown key.
+        """
+        if hasattr(items, 'items'):
+            # it's a dict
+            items = items.items()
+        for key, value in items:
+            self.setConfig(key, value)
+
+    def extendMarkdown(self, md: Markdown) -> None:
+        """
+        Add the various processors and patterns to the Markdown Instance.
+
+        This method must be overridden by every extension.
+
+        Arguments:
+            md: The Markdown instance.
+
+        """
+        raise NotImplementedError(
+            'Extension "%s.%s" must define an "extendMarkdown"'
+            'method.' % (self.__class__.__module__, self.__class__.__name__)
+        )

plugins/markdown_preview/markdown/extensions/abbr.py

@@ -0,0 +1,105 @@
+# Abbreviation Extension for Python-Markdown
+# ==========================================
+
+# This extension adds abbreviation handling to Python-Markdown.
+
+# See https://Python-Markdown.github.io/extensions/abbreviations
+# for documentation.
+
+# Original code Copyright 2007-2008 [Waylan Limberg](http://achinghead.com/)
+# and [Seemant Kulleen](http://www.kulleen.org/)
+
+# All changes Copyright 2008-2014 The Python Markdown Project
+
+# License: [BSD](https://opensource.org/licenses/bsd-license.php)
+
+"""
+This extension adds abbreviation handling to Python-Markdown.
+
+See the [documentation](https://Python-Markdown.github.io/extensions/abbreviations)
+for details.
+"""
+
+from __future__ import annotations
+
+from . import Extension
+from ..blockprocessors import BlockProcessor
+from ..inlinepatterns import InlineProcessor
+from ..util import AtomicString
+import re
+import xml.etree.ElementTree as etree
+
+
+class AbbrExtension(Extension):
+    """ Abbreviation Extension for Python-Markdown. """
+
+    def extendMarkdown(self, md):
+        """ Insert `AbbrPreprocessor` before `ReferencePreprocessor`. """
+        md.parser.blockprocessors.register(AbbrPreprocessor(md.parser), 'abbr', 16)
+
+
+class AbbrPreprocessor(BlockProcessor):
+    """ Abbreviation Preprocessor - parse text for abbr references. """
+
+    RE = re.compile(r'^[*]\[(?P<abbr>[^\]]*)\][ ]?:[ ]*\n?[ ]*(?P<title>.*)$', re.MULTILINE)
+
+    def test(self, parent, block):
+        return True
+
+    def run(self, parent, blocks):
+        """
+        Find and remove all Abbreviation references from the text.
+        Each reference is set as a new `AbbrPattern` in the markdown instance.
+
+        """
+        block = blocks.pop(0)
+        m = self.RE.search(block)
+        if m:
+            abbr = m.group('abbr').strip()
+            title = m.group('title').strip()
+            self.parser.md.inlinePatterns.register(
+                AbbrInlineProcessor(self._generate_pattern(abbr), title), 'abbr-%s' % abbr, 2
+            )
+            if block[m.end():].strip():
+                # Add any content after match back to blocks as separate block
+                blocks.insert(0, block[m.end():].lstrip('\n'))
+            if block[:m.start()].strip():
+                # Add any content before match back to blocks as separate block
+                blocks.insert(0, block[:m.start()].rstrip('\n'))
+            return True
+        # No match. Restore block.
+        blocks.insert(0, block)
+        return False
+
+    def _generate_pattern(self, text):
+        """
+        Given a string, returns an regex pattern to match that string.
+
+        'HTML' -> r'(?P<abbr>[H][T][M][L])'
+
+        Note: we force each char as a literal match (in brackets) as we don't
+        know what they will be beforehand.
+
+        """
+        chars = list(text)
+        for i in range(len(chars)):
+            chars[i] = r'[%s]' % chars[i]
+        return r'(?P<abbr>\b%s\b)' % (r''.join(chars))
+
+
+class AbbrInlineProcessor(InlineProcessor):
+    """ Abbreviation inline pattern. """
+
+    def __init__(self, pattern, title):
+        super().__init__(pattern)
+        self.title = title
+
+    def handleMatch(self, m, data):
+        abbr = etree.Element('abbr')
+        abbr.text = AtomicString(m.group('abbr'))
+        abbr.set('title', self.title)
+        return abbr, m.start(0), m.end(0)
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    return AbbrExtension(**kwargs)

plugins/markdown_preview/markdown/extensions/admonition.py

@@ -0,0 +1,179 @@
+# Admonition extension for Python-Markdown
+# ========================================
+
+# Adds rST-style admonitions. Inspired by [rST][] feature with the same name.
+
+# [rST]: http://docutils.sourceforge.net/docs/ref/rst/directives.html#specific-admonitions
+
+# See https://Python-Markdown.github.io/extensions/admonition
+# for documentation.
+
+# Original code Copyright [Tiago Serafim](https://www.tiagoserafim.com/).
+
+# All changes Copyright The Python Markdown Project
+
+# License: [BSD](https://opensource.org/licenses/bsd-license.php)
+
+
+"""
+Adds rST-style admonitions. Inspired by [rST][] feature with the same name.
+
+[rST]: http://docutils.sourceforge.net/docs/ref/rst/directives.html#specific-admonitions
+
+See the [documentation](https://Python-Markdown.github.io/extensions/admonition)
+for details.
+"""
+
+from __future__ import annotations
+
+from . import Extension
+from ..blockprocessors import BlockProcessor
+import xml.etree.ElementTree as etree
+import re
+
+
+class AdmonitionExtension(Extension):
+    """ Admonition extension for Python-Markdown. """
+
+    def extendMarkdown(self, md):
+        """ Add Admonition to Markdown instance. """
+        md.registerExtension(self)
+
+        md.parser.blockprocessors.register(AdmonitionProcessor(md.parser), 'admonition', 105)
+
+
+class AdmonitionProcessor(BlockProcessor):
+
+    CLASSNAME = 'admonition'
+    CLASSNAME_TITLE = 'admonition-title'
+    RE = re.compile(r'(?:^|\n)!!! ?([\w\-]+(?: +[\w\-]+)*)(?: +"(.*?)")? *(?:\n|$)')
+    RE_SPACES = re.compile('  +')
+
+    def __init__(self, parser):
+        """Initialization."""
+
+        super().__init__(parser)
+
+        self.current_sibling = None
+        self.content_indention = 0
+
+    def parse_content(self, parent, block):
+        """Get sibling admonition.
+
+        Retrieve the appropriate sibling element. This can get tricky when
+        dealing with lists.
+
+        """
+
+        old_block = block
+        the_rest = ''
+
+        # We already acquired the block via test
+        if self.current_sibling is not None:
+            sibling = self.current_sibling
+            block, the_rest = self.detab(block, self.content_indent)
+            self.current_sibling = None
+            self.content_indent = 0
+            return sibling, block, the_rest
+
+        sibling = self.lastChild(parent)
+
+        if sibling is None or sibling.tag != 'div' or sibling.get('class', '').find(self.CLASSNAME) == -1:
+            sibling = None
+        else:
+            # If the last child is a list and the content is sufficiently indented
+            # to be under it, then the content's sibling is in the list.
+            last_child = self.lastChild(sibling)
+            indent = 0
+            while last_child is not None:
+                if (
+                    sibling is not None and block.startswith(' ' * self.tab_length * 2) and
+                    last_child is not None and last_child.tag in ('ul', 'ol', 'dl')
+                ):
+
+                    # The expectation is that we'll find an `<li>` or `<dt>`.
+                    # We should get its last child as well.
+                    sibling = self.lastChild(last_child)
+                    last_child = self.lastChild(sibling) if sibling is not None else None
+
+                    # Context has been lost at this point, so we must adjust the
+                    # text's indentation level so it will be evaluated correctly
+                    # under the list.
+                    block = block[self.tab_length:]
+                    indent += self.tab_length
+                else:
+                    last_child = None
+
+            if not block.startswith(' ' * self.tab_length):
+                sibling = None
+
+            if sibling is not None:
+                indent += self.tab_length
+                block, the_rest = self.detab(old_block, indent)
+                self.current_sibling = sibling
+                self.content_indent = indent
+
+        return sibling, block, the_rest
+
+    def test(self, parent, block):
+
+        if self.RE.search(block):
+            return True
+        else:
+            return self.parse_content(parent, block)[0] is not None
+
+    def run(self, parent, blocks):
+        block = blocks.pop(0)
+        m = self.RE.search(block)
+
+        if m:
+            if m.start() > 0:
+                self.parser.parseBlocks(parent, [block[:m.start()]])
+            block = block[m.end():]  # removes the first line
+            block, theRest = self.detab(block)
+        else:
+            sibling, block, theRest = self.parse_content(parent, block)
+
+        if m:
+            klass, title = self.get_class_and_title(m)
+            div = etree.SubElement(parent, 'div')
+            div.set('class', '{} {}'.format(self.CLASSNAME, klass))
+            if title:
+                p = etree.SubElement(div, 'p')
+                p.text = title
+                p.set('class', self.CLASSNAME_TITLE)
+        else:
+            # Sibling is a list item, but we need to wrap it's content should be wrapped in <p>
+            if sibling.tag in ('li', 'dd') and sibling.text:
+                text = sibling.text
+                sibling.text = ''
+                p = etree.SubElement(sibling, 'p')
+                p.text = text
+
+            div = sibling
+
+        self.parser.parseChunk(div, block)
+
+        if theRest:
+            # This block contained unindented line(s) after the first indented
+            # line. Insert these lines as the first block of the master blocks
+            # list for future processing.
+            blocks.insert(0, theRest)
+
+    def get_class_and_title(self, match):
+        klass, title = match.group(1).lower(), match.group(2)
+        klass = self.RE_SPACES.sub(' ', klass)
+        if title is None:
+            # no title was provided, use the capitalized class name as title
+            # e.g.: `!!! note` will render
+            # `<p class="admonition-title">Note</p>`
+            title = klass.split(' ', 1)[0].capitalize()
+        elif title == '':
+            # an explicit blank title should not be rendered
+            # e.g.: `!!! warning ""` will *not* render `p` with a title
+            title = None
+        return klass, title
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    return AdmonitionExtension(**kwargs)

plugins/markdown_preview/markdown/extensions/attr_list.py

@@ -0,0 +1,179 @@
+# Attribute List Extension for Python-Markdown
+# ============================================
+
+# Adds attribute list syntax. Inspired by
+# [Maruku](http://maruku.rubyforge.org/proposal.html#attribute_lists)'s
+# feature of the same name.
+
+# See https://Python-Markdown.github.io/extensions/attr_list
+# for documentation.
+
+# Original code Copyright 2011 [Waylan Limberg](http://achinghead.com/).
+
+# All changes Copyright 2011-2014 The Python Markdown Project
+
+# License: [BSD](https://opensource.org/licenses/bsd-license.php)
+
+"""
+ Adds attribute list syntax. Inspired by
+[Maruku](http://maruku.rubyforge.org/proposal.html#attribute_lists)'s
+feature of the same name.
+
+See the [documentation](https://Python-Markdown.github.io/extensions/attr_list)
+for details.
+"""
+
+from __future__ import annotations
+from typing import TYPE_CHECKING
+
+from . import Extension
+from ..treeprocessors import Treeprocessor
+import re
+
+if TYPE_CHECKING:  # pragma: no cover
+    from xml.etree.ElementTree import Element
+
+
+def _handle_double_quote(s, t):
+    k, v = t.split('=', 1)
+    return k, v.strip('"')
+
+
+def _handle_single_quote(s, t):
+    k, v = t.split('=', 1)
+    return k, v.strip("'")
+
+
+def _handle_key_value(s, t):
+    return t.split('=', 1)
+
+
+def _handle_word(s, t):
+    if t.startswith('.'):
+        return '.', t[1:]
+    if t.startswith('#'):
+        return 'id', t[1:]
+    return t, t
+
+
+_scanner = re.Scanner([
+    (r'[^ =]+=".*?"', _handle_double_quote),
+    (r"[^ =]+='.*?'", _handle_single_quote),
+    (r'[^ =]+=[^ =]+', _handle_key_value),
+    (r'[^ =]+', _handle_word),
+    (r' ', None)
+])
+
+
+def get_attrs(str: str) -> list[tuple[str, str]]:
+    """ Parse attribute list and return a list of attribute tuples. """
+    return _scanner.scan(str)[0]
+
+
+def isheader(elem: Element) -> bool:
+    return elem.tag in ['h1', 'h2', 'h3', 'h4', 'h5', 'h6']
+
+
+class AttrListTreeprocessor(Treeprocessor):
+
+    BASE_RE = r'\{\:?[ ]*([^\}\n ][^\}\n]*)[ ]*\}'
+    HEADER_RE = re.compile(r'[ ]+{}[ ]*$'.format(BASE_RE))
+    BLOCK_RE = re.compile(r'\n[ ]*{}[ ]*$'.format(BASE_RE))
+    INLINE_RE = re.compile(r'^{}'.format(BASE_RE))
+    NAME_RE = re.compile(r'[^A-Z_a-z\u00c0-\u00d6\u00d8-\u00f6\u00f8-\u02ff'
+                         r'\u0370-\u037d\u037f-\u1fff\u200c-\u200d'
+                         r'\u2070-\u218f\u2c00-\u2fef\u3001-\ud7ff'
+                         r'\uf900-\ufdcf\ufdf0-\ufffd'
+                         r'\:\-\.0-9\u00b7\u0300-\u036f\u203f-\u2040]+')
+
+    def run(self, doc: Element):
+        for elem in doc.iter():
+            if self.md.is_block_level(elem.tag):
+                # Block level: check for `attrs` on last line of text
+                RE = self.BLOCK_RE
+                if isheader(elem) or elem.tag in ['dt', 'td', 'th']:
+                    # header, def-term, or table cell: check for attributes at end of element
+                    RE = self.HEADER_RE
+                if len(elem) and elem.tag == 'li':
+                    # special case list items. children may include a `ul` or `ol`.
+                    pos = None
+                    # find the `ul` or `ol` position
+                    for i, child in enumerate(elem):
+                        if child.tag in ['ul', 'ol']:
+                            pos = i
+                            break
+                    if pos is None and elem[-1].tail:
+                        # use tail of last child. no `ul` or `ol`.
+                        m = RE.search(elem[-1].tail)
+                        if m:
+                            self.assign_attrs(elem, m.group(1))
+                            elem[-1].tail = elem[-1].tail[:m.start()]
+                    elif pos is not None and pos > 0 and elem[pos-1].tail:
+                        # use tail of last child before `ul` or `ol`
+                        m = RE.search(elem[pos-1].tail)
+                        if m:
+                            self.assign_attrs(elem, m.group(1))
+                            elem[pos-1].tail = elem[pos-1].tail[:m.start()]
+                    elif elem.text:
+                        # use text. `ul` is first child.
+                        m = RE.search(elem.text)
+                        if m:
+                            self.assign_attrs(elem, m.group(1))
+                            elem.text = elem.text[:m.start()]
+                elif len(elem) and elem[-1].tail:
+                    # has children. Get from tail of last child
+                    m = RE.search(elem[-1].tail)
+                    if m:
+                        self.assign_attrs(elem, m.group(1))
+                        elem[-1].tail = elem[-1].tail[:m.start()]
+                        if isheader(elem):
+                            # clean up trailing #s
+                            elem[-1].tail = elem[-1].tail.rstrip('#').rstrip()
+                elif elem.text:
+                    # no children. Get from text.
+                    m = RE.search(elem.text)
+                    if m:
+                        self.assign_attrs(elem, m.group(1))
+                        elem.text = elem.text[:m.start()]
+                        if isheader(elem):
+                            # clean up trailing #s
+                            elem.text = elem.text.rstrip('#').rstrip()
+            else:
+                # inline: check for `attrs` at start of tail
+                if elem.tail:
+                    m = self.INLINE_RE.match(elem.tail)
+                    if m:
+                        self.assign_attrs(elem, m.group(1))
+                        elem.tail = elem.tail[m.end():]
+
+    def assign_attrs(self, elem: Element, attrs: str) -> None:
+        """ Assign `attrs` to element. """
+        for k, v in get_attrs(attrs):
+            if k == '.':
+                # add to class
+                cls = elem.get('class')
+                if cls:
+                    elem.set('class', '{} {}'.format(cls, v))
+                else:
+                    elem.set('class', v)
+            else:
+                # assign attribute `k` with `v`
+                elem.set(self.sanitize_name(k), v)
+
+    def sanitize_name(self, name: str) -> str:
+        """
+        Sanitize name as 'an XML Name, minus the ":"'.
+        See https://www.w3.org/TR/REC-xml-names/#NT-NCName
+        """
+        return self.NAME_RE.sub('_', name)
+
+
+class AttrListExtension(Extension):
+    """ Attribute List extension for Python-Markdown """
+    def extendMarkdown(self, md):
+        md.treeprocessors.register(AttrListTreeprocessor(md), 'attr_list', 8)
+        md.registerExtension(self)
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    return AttrListExtension(**kwargs)

plugins/markdown_preview/markdown/extensions/codehilite.py

@@ -0,0 +1,338 @@
+# CodeHilite Extension for Python-Markdown
+# ========================================
+
+# Adds code/syntax highlighting to standard Python-Markdown code blocks.
+
+# See https://Python-Markdown.github.io/extensions/code_hilite
+# for documentation.
+
+# Original code Copyright 2006-2008 [Waylan Limberg](http://achinghead.com/).
+
+# All changes Copyright 2008-2014 The Python Markdown Project
+
+# License: [BSD](https://opensource.org/licenses/bsd-license.php)
+
+"""
+Adds code/syntax highlighting to standard Python-Markdown code blocks.
+
+See the [documentation](https://Python-Markdown.github.io/extensions/code_hilite)
+for details.
+"""
+
+from __future__ import annotations
+
+from . import Extension
+from ..treeprocessors import Treeprocessor
+from ..util import parseBoolValue
+
+try:  # pragma: no cover
+    from pygments import highlight
+    from pygments.lexers import get_lexer_by_name, guess_lexer
+    from pygments.formatters import get_formatter_by_name
+    from pygments.util import ClassNotFound
+    pygments = True
+except ImportError:  # pragma: no cover
+    pygments = False
+
+
+def parse_hl_lines(expr: str) -> list[int]:
+    """Support our syntax for emphasizing certain lines of code.
+
+    `expr` should be like '1 2' to emphasize lines 1 and 2 of a code block.
+    Returns a list of integers, the line numbers to emphasize.
+    """
+    if not expr:
+        return []
+
+    try:
+        return list(map(int, expr.split()))
+    except ValueError:  # pragma: no cover
+        return []
+
+
+# ------------------ The Main CodeHilite Class ----------------------
+class CodeHilite:
+    """
+    Determine language of source code, and pass it on to the Pygments highlighter.
+
+    Usage:
+
+    ```python
+    code = CodeHilite(src=some_code, lang='python')
+    html = code.hilite()
+    ```
+
+    Arguments:
+        src: Source string or any object with a `.readline` attribute.
+
+    Keyword arguments:
+        lang (str): String name of Pygments lexer to use for highlighting. Default: `None`.
+        guess_lang (bool): Auto-detect which lexer to use.
+            Ignored if `lang` is set to a valid value. Default: `True`.
+        use_pygments (bool): Pass code to Pygments for code highlighting. If `False`, the code is
+            instead wrapped for highlighting by a JavaScript library. Default: `True`.
+        pygments_formatter (str): The name of a Pygments formatter or a formatter class used for
+            highlighting the code blocks. Default: `html`.
+        linenums (bool): An alias to Pygments `linenos` formatter option. Default: `None`.
+        css_class (str): An alias to Pygments `cssclass` formatter option. Default: 'codehilite'.
+        lang_prefix (str): Prefix prepended to the language. Default: "language-".
+
+    Other Options:
+
+    Any other options are accepted and passed on to the lexer and formatter. Therefore,
+    valid options include any options which are accepted by the `html` formatter or
+    whichever lexer the code's language uses. Note that most lexers do not have any
+    options. However, a few have very useful options, such as PHP's `startinline` option.
+    Any invalid options are ignored without error.
+
+    * **Formatter options**: <https://pygments.org/docs/formatters/#HtmlFormatter>
+    * **Lexer Options**: <https://pygments.org/docs/lexers/>
+
+    Additionally, when Pygments is enabled, the code's language is passed to the
+    formatter as an extra option `lang_str`, whose value being `{lang_prefix}{lang}`.
+    This option has no effect to the Pygments' builtin formatters.
+
+    Advanced Usage:
+
+    ```python
+    code = CodeHilite(
+        src = some_code,
+        lang = 'php',
+        startinline = True,      # Lexer option. Snippet does not start with `<?php`.
+        linenostart = 42,        # Formatter option. Snippet starts on line 42.
+        hl_lines = [45, 49, 50], # Formatter option. Highlight lines 45, 49, and 50.
+        linenos = 'inline'       # Formatter option. Avoid alignment problems.
+    )
+    html = code.hilite()
+    ```
+
+    """
+
+    def __init__(self, src: str, **options):
+        self.src = src
+        self.lang = options.pop('lang', None)
+        self.guess_lang = options.pop('guess_lang', True)
+        self.use_pygments = options.pop('use_pygments', True)
+        self.lang_prefix = options.pop('lang_prefix', 'language-')
+        self.pygments_formatter = options.pop('pygments_formatter', 'html')
+
+        if 'linenos' not in options:
+            options['linenos'] = options.pop('linenums', None)
+        if 'cssclass' not in options:
+            options['cssclass'] = options.pop('css_class', 'codehilite')
+        if 'wrapcode' not in options:
+            # Override Pygments default
+            options['wrapcode'] = True
+        # Disallow use of `full` option
+        options['full'] = False
+
+        self.options = options
+
+    def hilite(self, shebang=True) -> str:
+        """
+        Pass code to the [Pygments](https://pygments.org/) highlighter with
+        optional line numbers. The output should then be styled with CSS to
+        your liking. No styles are applied by default - only styling hooks
+        (i.e.: `<span class="k">`).
+
+        returns : A string of html.
+
+        """
+
+        self.src = self.src.strip('\n')
+
+        if self.lang is None and shebang:
+            self._parseHeader()
+
+        if pygments and self.use_pygments:
+            try:
+                lexer = get_lexer_by_name(self.lang, **self.options)
+            except ValueError:
+                try:
+                    if self.guess_lang:
+                        lexer = guess_lexer(self.src, **self.options)
+                    else:
+                        lexer = get_lexer_by_name('text', **self.options)
+                except ValueError:  # pragma: no cover
+                    lexer = get_lexer_by_name('text', **self.options)
+            if not self.lang:
+                # Use the guessed lexer's language instead
+                self.lang = lexer.aliases[0]
+            lang_str = f'{self.lang_prefix}{self.lang}'
+            if isinstance(self.pygments_formatter, str):
+                try:
+                    formatter = get_formatter_by_name(self.pygments_formatter, **self.options)
+                except ClassNotFound:
+                    formatter = get_formatter_by_name('html', **self.options)
+            else:
+                formatter = self.pygments_formatter(lang_str=lang_str, **self.options)
+            return highlight(self.src, lexer, formatter)
+        else:
+            # just escape and build markup usable by JavaScript highlighting libraries
+            txt = self.src.replace('&', '&amp;')
+            txt = txt.replace('<', '&lt;')
+            txt = txt.replace('>', '&gt;')
+            txt = txt.replace('"', '&quot;')
+            classes = []
+            if self.lang:
+                classes.append('{}{}'.format(self.lang_prefix, self.lang))
+            if self.options['linenos']:
+                classes.append('linenums')
+            class_str = ''
+            if classes:
+                class_str = ' class="{}"'.format(' '.join(classes))
+            return '<pre class="{}"><code{}>{}\n</code></pre>\n'.format(
+                self.options['cssclass'],
+                class_str,
+                txt
+            )
+
+    def _parseHeader(self):
+        """
+        Determines language of a code block from shebang line and whether the
+        said line should be removed or left in place. If the shebang line
+        contains a path (even a single /) then it is assumed to be a real
+        shebang line and left alone. However, if no path is given
+        (e.i.: `#!python` or `:::python`) then it is assumed to be a mock shebang
+        for language identification of a code fragment and removed from the
+        code block prior to processing for code highlighting. When a mock
+        shebang (e.i: `#!python`) is found, line numbering is turned on. When
+        colons are found in place of a shebang (e.i.: `:::python`), line
+        numbering is left in the current state - off by default.
+
+        Also parses optional list of highlight lines, like:
+
+            :::python hl_lines="1 3"
+        """
+
+        import re
+
+        # split text into lines
+        lines = self.src.split("\n")
+        # pull first line to examine
+        fl = lines.pop(0)
+
+        c = re.compile(r'''
+            (?:(?:^::+)|(?P<shebang>^[#]!)) # Shebang or 2 or more colons
+            (?P<path>(?:/\w+)*[/ ])?        # Zero or 1 path
+            (?P<lang>[\w#.+-]*)             # The language
+            \s*                             # Arbitrary whitespace
+            # Optional highlight lines, single- or double-quote-delimited
+            (hl_lines=(?P<quot>"|')(?P<hl_lines>.*?)(?P=quot))?
+            ''',  re.VERBOSE)
+        # search first line for shebang
+        m = c.search(fl)
+        if m:
+            # we have a match
+            try:
+                self.lang = m.group('lang').lower()
+            except IndexError:  # pragma: no cover
+                self.lang = None
+            if m.group('path'):
+                # path exists - restore first line
+                lines.insert(0, fl)
+            if self.options['linenos'] is None and m.group('shebang'):
+                # Overridable and Shebang exists - use line numbers
+                self.options['linenos'] = True
+
+            self.options['hl_lines'] = parse_hl_lines(m.group('hl_lines'))
+        else:
+            # No match
+            lines.insert(0, fl)
+
+        self.src = "\n".join(lines).strip("\n")
+
+
+# ------------------ The Markdown Extension -------------------------------
+
+
+class HiliteTreeprocessor(Treeprocessor):
+    """ Highlight source code in code blocks. """
+
+    def code_unescape(self, text):
+        """Unescape code."""
+        text = text.replace("&lt;", "<")
+        text = text.replace("&gt;", ">")
+        # Escaped '&' should be replaced at the end to avoid
+        # conflicting with < and >.
+        text = text.replace("&amp;", "&")
+        return text
+
+    def run(self, root):
+        """ Find code blocks and store in `htmlStash`. """
+        blocks = root.iter('pre')
+        for block in blocks:
+            if len(block) == 1 and block[0].tag == 'code':
+                local_config = self.config.copy()
+                code = CodeHilite(
+                    self.code_unescape(block[0].text),
+                    tab_length=self.md.tab_length,
+                    style=local_config.pop('pygments_style', 'default'),
+                    **local_config
+                )
+                placeholder = self.md.htmlStash.store(code.hilite())
+                # Clear code block in `etree` instance
+                block.clear()
+                # Change to `p` element which will later
+                # be removed when inserting raw html
+                block.tag = 'p'
+                block.text = placeholder
+
+
+class CodeHiliteExtension(Extension):
+    """ Add source code highlighting to markdown code blocks. """
+
+    def __init__(self, **kwargs):
+        # define default configs
+        self.config = {
+            'linenums': [
+                None, "Use lines numbers. True|table|inline=yes, False=no, None=auto. Default: `None`."
+            ],
+            'guess_lang': [
+                True, "Automatic language detection - Default: `True`."
+            ],
+            'css_class': [
+                "codehilite", "Set class name for wrapper <div> - Default: `codehilite`."
+            ],
+            'pygments_style': [
+                'default', 'Pygments HTML Formatter Style (Colorscheme). Default: `default`.'
+            ],
+            'noclasses': [
+                False, 'Use inline styles instead of CSS classes - Default `False`.'
+            ],
+            'use_pygments': [
+                True, 'Highlight code blocks with pygments. Disable if using a JavaScript library. Default: `True`.'
+            ],
+            'lang_prefix': [
+                'language-', 'Prefix prepended to the language when `use_pygments` is false. Default: `language-`.'
+            ],
+            'pygments_formatter': [
+                'html', 'Use a specific formatter for Pygments highlighting. Default: `html`.'
+            ],
+        }
+        """ Default configuration options. """
+
+        for key, value in kwargs.items():
+            if key in self.config:
+                self.setConfig(key, value)
+            else:
+                # manually set unknown keywords.
+                if isinstance(value, str):
+                    try:
+                        # Attempt to parse `str` as a boolean value
+                        value = parseBoolValue(value, preserve_none=True)
+                    except ValueError:
+                        pass  # Assume it's not a boolean value. Use as-is.
+                self.config[key] = [value, '']
+
+    def extendMarkdown(self, md):
+        """ Add `HilitePostprocessor` to Markdown instance. """
+        hiliter = HiliteTreeprocessor(md)
+        hiliter.config = self.getConfigs()
+        md.treeprocessors.register(hiliter, 'hilite', 30)
+
+        md.registerExtension(self)
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    return CodeHiliteExtension(**kwargs)

plugins/markdown_preview/markdown/extensions/def_list.py

@@ -0,0 +1,119 @@
+# Definition List Extension for Python-Markdown
+# =============================================
+
+# Adds parsing of Definition Lists to Python-Markdown.
+
+# See https://Python-Markdown.github.io/extensions/definition_lists
+# for documentation.
+
+# Original code Copyright 2008 [Waylan Limberg](http://achinghead.com)
+
+# All changes Copyright 2008-2014 The Python Markdown Project
+
+# License: [BSD](https://opensource.org/licenses/bsd-license.php)
+
+"""
+Adds parsing of Definition Lists to Python-Markdown.
+
+See the [documentation](https://Python-Markdown.github.io/extensions/definition_lists)
+for details.
+"""
+
+from __future__ import annotations
+
+from . import Extension
+from ..blockprocessors import BlockProcessor, ListIndentProcessor
+import xml.etree.ElementTree as etree
+import re
+
+
+class DefListProcessor(BlockProcessor):
+    """ Process Definition Lists. """
+
+    RE = re.compile(r'(^|\n)[ ]{0,3}:[ ]{1,3}(.*?)(\n|$)')
+    NO_INDENT_RE = re.compile(r'^[ ]{0,3}[^ :]')
+
+    def test(self, parent, block):
+        return bool(self.RE.search(block))
+
+    def run(self, parent, blocks):
+
+        raw_block = blocks.pop(0)
+        m = self.RE.search(raw_block)
+        terms = [term.strip() for term in
+                 raw_block[:m.start()].split('\n') if term.strip()]
+        block = raw_block[m.end():]
+        no_indent = self.NO_INDENT_RE.match(block)
+        if no_indent:
+            d, theRest = (block, None)
+        else:
+            d, theRest = self.detab(block)
+        if d:
+            d = '{}\n{}'.format(m.group(2), d)
+        else:
+            d = m.group(2)
+        sibling = self.lastChild(parent)
+        if not terms and sibling is None:
+            # This is not a definition item. Most likely a paragraph that
+            # starts with a colon at the beginning of a document or list.
+            blocks.insert(0, raw_block)
+            return False
+        if not terms and sibling.tag == 'p':
+            # The previous paragraph contains the terms
+            state = 'looselist'
+            terms = sibling.text.split('\n')
+            parent.remove(sibling)
+            # Acquire new sibling
+            sibling = self.lastChild(parent)
+        else:
+            state = 'list'
+
+        if sibling is not None and sibling.tag == 'dl':
+            # This is another item on an existing list
+            dl = sibling
+            if not terms and len(dl) and dl[-1].tag == 'dd' and len(dl[-1]):
+                state = 'looselist'
+        else:
+            # This is a new list
+            dl = etree.SubElement(parent, 'dl')
+        # Add terms
+        for term in terms:
+            dt = etree.SubElement(dl, 'dt')
+            dt.text = term
+        # Add definition
+        self.parser.state.set(state)
+        dd = etree.SubElement(dl, 'dd')
+        self.parser.parseBlocks(dd, [d])
+        self.parser.state.reset()
+
+        if theRest:
+            blocks.insert(0, theRest)
+
+
+class DefListIndentProcessor(ListIndentProcessor):
+    """ Process indented children of definition list items. """
+
+    # Definition lists need to be aware of all list types
+    ITEM_TYPES = ['dd', 'li']
+    """ Include `dd` in list item types. """
+    LIST_TYPES = ['dl', 'ol', 'ul']
+    """ Include `dl` is list types. """
+
+    def create_item(self, parent, block):
+        """ Create a new `dd` or `li` (depending on parent) and parse the block with it as the parent. """
+
+        dd = etree.SubElement(parent, 'dd')
+        self.parser.parseBlocks(dd, [block])
+
+
+class DefListExtension(Extension):
+    """ Add definition lists to Markdown. """
+
+    def extendMarkdown(self, md):
+        """ Add an instance of `DefListProcessor` to `BlockParser`. """
+        md.parser.blockprocessors.register(DefListIndentProcessor(md.parser), 'defindent', 85)
+        md.parser.blockprocessors.register(DefListProcessor(md.parser), 'deflist', 25)
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    return DefListExtension(**kwargs)

plugins/markdown_preview/markdown/extensions/extra.py

@@ -0,0 +1,66 @@
+# Python-Markdown Extra Extension
+# ===============================
+
+# A compilation of various Python-Markdown extensions that imitates
+# [PHP Markdown Extra](http://michelf.com/projects/php-markdown/extra/).
+
+# See https://Python-Markdown.github.io/extensions/extra
+# for documentation.
+
+# Copyright The Python Markdown Project
+
+# License: [BSD](https://opensource.org/licenses/bsd-license.php)
+
+"""
+A compilation of various Python-Markdown extensions that imitates
+[PHP Markdown Extra](http://michelf.com/projects/php-markdown/extra/).
+
+Note that each of the individual extensions still need to be available
+on your `PYTHONPATH`. This extension simply wraps them all up as a
+convenience so that only one extension needs to be listed when
+initiating Markdown. See the documentation for each individual
+extension for specifics about that extension.
+
+There may be additional extensions that are distributed with
+Python-Markdown that are not included here in Extra. Those extensions
+are not part of PHP Markdown Extra, and therefore, not part of
+Python-Markdown Extra. If you really would like Extra to include
+additional extensions, we suggest creating your own clone of Extra
+under a different name. You could also edit the `extensions` global
+variable defined below, but be aware that such changes may be lost
+when you upgrade to any future version of Python-Markdown.
+
+See the [documentation](https://Python-Markdown.github.io/extensions/extra)
+for details.
+"""
+
+from __future__ import annotations
+
+from . import Extension
+
+extensions = [
+    'fenced_code',
+    'footnotes',
+    'attr_list',
+    'def_list',
+    'tables',
+    'abbr',
+    'md_in_html'
+]
+""" The list of included extensions. """
+
+
+class ExtraExtension(Extension):
+    """ Add various extensions to Markdown class."""
+
+    def __init__(self, **kwargs):
+        """ `config` is a dumb holder which gets passed to the actual extension later. """
+        self.config = kwargs
+
+    def extendMarkdown(self, md):
+        """ Register extension instances. """
+        md.registerExtensions(extensions, self.config)
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    return ExtraExtension(**kwargs)

plugins/markdown_preview/markdown/extensions/fenced_code.py

@@ -0,0 +1,182 @@
+# Fenced Code Extension for Python Markdown
+# =========================================
+
+# This extension adds Fenced Code Blocks to Python-Markdown.
+
+# See https://Python-Markdown.github.io/extensions/fenced_code_blocks
+# for documentation.
+
+# Original code Copyright 2007-2008 [Waylan Limberg](http://achinghead.com/).
+
+# All changes Copyright 2008-2014 The Python Markdown Project
+
+# License: [BSD](https://opensource.org/licenses/bsd-license.php)
+
+"""
+This extension adds Fenced Code Blocks to Python-Markdown.
+
+See the [documentation](https://Python-Markdown.github.io/extensions/fenced_code_blocks)
+for details.
+"""
+
+from __future__ import annotations
+
+from textwrap import dedent
+from . import Extension
+from ..preprocessors import Preprocessor
+from .codehilite import CodeHilite, CodeHiliteExtension, parse_hl_lines
+from .attr_list import get_attrs, AttrListExtension
+from ..util import parseBoolValue
+from ..serializers import _escape_attrib_html
+import re
+
+
+class FencedCodeExtension(Extension):
+    def __init__(self, **kwargs):
+        self.config = {
+            'lang_prefix': ['language-', 'Prefix prepended to the language. Default: "language-"']
+        }
+        """ Default configuration options. """
+        super().__init__(**kwargs)
+
+    def extendMarkdown(self, md):
+        """ Add `FencedBlockPreprocessor` to the Markdown instance. """
+        md.registerExtension(self)
+
+        md.preprocessors.register(FencedBlockPreprocessor(md, self.getConfigs()), 'fenced_code_block', 25)
+
+
+class FencedBlockPreprocessor(Preprocessor):
+    """ Find and extract fenced code blocks. """
+
+    FENCED_BLOCK_RE = re.compile(
+        dedent(r'''
+            (?P<fence>^(?:~{3,}|`{3,}))[ ]*                          # opening fence
+            ((\{(?P<attrs>[^\}\n]*)\})|                              # (optional {attrs} or
+            (\.?(?P<lang>[\w#.+-]*)[ ]*)?                            # optional (.)lang
+            (hl_lines=(?P<quot>"|')(?P<hl_lines>.*?)(?P=quot)[ ]*)?) # optional hl_lines)
+            \n                                                       # newline (end of opening fence)
+            (?P<code>.*?)(?<=\n)                                     # the code block
+            (?P=fence)[ ]*$                                          # closing fence
+        '''),
+        re.MULTILINE | re.DOTALL | re.VERBOSE
+    )
+
+    def __init__(self, md, config):
+        super().__init__(md)
+        self.config = config
+        self.checked_for_deps = False
+        self.codehilite_conf = {}
+        self.use_attr_list = False
+        # List of options to convert to boolean values
+        self.bool_options = [
+            'linenums',
+            'guess_lang',
+            'noclasses',
+            'use_pygments'
+        ]
+
+    def run(self, lines):
+        """ Match and store Fenced Code Blocks in the `HtmlStash`. """
+
+        # Check for dependent extensions
+        if not self.checked_for_deps:
+            for ext in self.md.registeredExtensions:
+                if isinstance(ext, CodeHiliteExtension):
+                    self.codehilite_conf = ext.getConfigs()
+                if isinstance(ext, AttrListExtension):
+                    self.use_attr_list = True
+
+            self.checked_for_deps = True
+
+        text = "\n".join(lines)
+        while 1:
+            m = self.FENCED_BLOCK_RE.search(text)
+            if m:
+                lang, id, classes, config = None, '', [], {}
+                if m.group('attrs'):
+                    id, classes, config = self.handle_attrs(get_attrs(m.group('attrs')))
+                    if len(classes):
+                        lang = classes.pop(0)
+                else:
+                    if m.group('lang'):
+                        lang = m.group('lang')
+                    if m.group('hl_lines'):
+                        # Support `hl_lines` outside of `attrs` for backward-compatibility
+                        config['hl_lines'] = parse_hl_lines(m.group('hl_lines'))
+
+                # If `config` is not empty, then the `codehighlite` extension
+                # is enabled, so we call it to highlight the code
+                if self.codehilite_conf and self.codehilite_conf['use_pygments'] and config.get('use_pygments', True):
+                    local_config = self.codehilite_conf.copy()
+                    local_config.update(config)
+                    # Combine classes with `cssclass`. Ensure `cssclass` is at end
+                    # as Pygments appends a suffix under certain circumstances.
+                    # Ignore ID as Pygments does not offer an option to set it.
+                    if classes:
+                        local_config['css_class'] = '{} {}'.format(
+                            ' '.join(classes),
+                            local_config['css_class']
+                        )
+                    highliter = CodeHilite(
+                        m.group('code'),
+                        lang=lang,
+                        style=local_config.pop('pygments_style', 'default'),
+                        **local_config
+                    )
+
+                    code = highliter.hilite(shebang=False)
+                else:
+                    id_attr = lang_attr = class_attr = kv_pairs = ''
+                    if lang:
+                        prefix = self.config.get('lang_prefix', 'language-')
+                        lang_attr = f' class="{prefix}{_escape_attrib_html(lang)}"'
+                    if classes:
+                        class_attr = f' class="{_escape_attrib_html(" ".join(classes))}"'
+                    if id:
+                        id_attr = f' id="{_escape_attrib_html(id)}"'
+                    if self.use_attr_list and config and not config.get('use_pygments', False):
+                        # Only assign key/value pairs to code element if `attr_list` extension is enabled, key/value
+                        # pairs were defined on the code block, and the `use_pygments` key was not set to `True`. The
+                        # `use_pygments` key could be either set to `False` or not defined. It is omitted from output.
+                        kv_pairs = ''.join(
+                            f' {k}="{_escape_attrib_html(v)}"' for k, v in config.items() if k != 'use_pygments'
+                        )
+                    code = self._escape(m.group('code'))
+                    code = f'<pre{id_attr}{class_attr}><code{lang_attr}{kv_pairs}>{code}</code></pre>'
+
+                placeholder = self.md.htmlStash.store(code)
+                text = f'{text[:m.start()]}\n{placeholder}\n{text[m.end():]}'
+            else:
+                break
+        return text.split("\n")
+
+    def handle_attrs(self, attrs):
+        """ Return tuple: `(id, [list, of, classes], {configs})` """
+        id = ''
+        classes = []
+        configs = {}
+        for k, v in attrs:
+            if k == 'id':
+                id = v
+            elif k == '.':
+                classes.append(v)
+            elif k == 'hl_lines':
+                configs[k] = parse_hl_lines(v)
+            elif k in self.bool_options:
+                configs[k] = parseBoolValue(v, fail_on_errors=False, preserve_none=True)
+            else:
+                configs[k] = v
+        return id, classes, configs
+
+    def _escape(self, txt):
+        """ basic html escaping """
+        txt = txt.replace('&', '&amp;')
+        txt = txt.replace('<', '&lt;')
+        txt = txt.replace('>', '&gt;')
+        txt = txt.replace('"', '&quot;')
+        return txt
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    return FencedCodeExtension(**kwargs)

plugins/markdown_preview/markdown/extensions/footnotes.py

@@ -0,0 +1,416 @@
+# Footnotes Extension for Python-Markdown
+# =======================================
+
+# Adds footnote handling to Python-Markdown.
+
+# See https://Python-Markdown.github.io/extensions/footnotes
+# for documentation.
+
+# Copyright The Python Markdown Project
+
+# License: [BSD](https://opensource.org/licenses/bsd-license.php)
+
+"""
+Adds footnote handling to Python-Markdown.
+
+See the [documentation](https://Python-Markdown.github.io/extensions/footnotes)
+for details.
+"""
+
+from __future__ import annotations
+
+from . import Extension
+from ..blockprocessors import BlockProcessor
+from ..inlinepatterns import InlineProcessor
+from ..treeprocessors import Treeprocessor
+from ..postprocessors import Postprocessor
+from .. import util
+from collections import OrderedDict
+import re
+import copy
+import xml.etree.ElementTree as etree
+
+FN_BACKLINK_TEXT = util.STX + "zz1337820767766393qq" + util.ETX
+NBSP_PLACEHOLDER = util.STX + "qq3936677670287331zz" + util.ETX
+RE_REF_ID = re.compile(r'(fnref)(\d+)')
+
+
+class FootnoteExtension(Extension):
+    """ Footnote Extension. """
+
+    def __init__(self, **kwargs):
+        """ Setup configs. """
+
+        self.config = {
+            'PLACE_MARKER': [
+                '///Footnotes Go Here///', 'The text string that marks where the footnotes go'
+            ],
+            'UNIQUE_IDS': [
+                False, 'Avoid name collisions across multiple calls to `reset()`.'
+            ],
+            'BACKLINK_TEXT': [
+                '↩', "The text string that links from the footnote to the reader's place."
+            ],
+            'SUPERSCRIPT_TEXT': [
+                '{}', "The text string that links from the reader's place to the footnote."
+            ],
+            'BACKLINK_TITLE': [
+                'Jump back to footnote %d in the text',
+                'The text string used for the title HTML attribute of the backlink. '
+                '%d will be replaced by the footnote number.'
+            ],
+            'SEPARATOR': [
+                ':', 'Footnote separator.'
+            ]
+        }
+        """ Default configuration options. """
+        super().__init__(**kwargs)
+
+        # In multiple invocations, emit links that don't get tangled.
+        self.unique_prefix = 0
+        self.found_refs = {}
+        self.used_refs = set()
+
+        self.reset()
+
+    def extendMarkdown(self, md):
+        """ Add pieces to Markdown. """
+        md.registerExtension(self)
+        self.parser = md.parser
+        self.md = md
+        # Insert a `blockprocessor` before `ReferencePreprocessor`
+        md.parser.blockprocessors.register(FootnoteBlockProcessor(self), 'footnote', 17)
+
+        # Insert an inline pattern before `ImageReferencePattern`
+        FOOTNOTE_RE = r'\[\^([^\]]*)\]'  # blah blah [^1] blah
+        md.inlinePatterns.register(FootnoteInlineProcessor(FOOTNOTE_RE, self), 'footnote', 175)
+        # Insert a tree-processor that would actually add the footnote div
+        # This must be before all other tree-processors (i.e., `inline` and
+        # `codehilite`) so they can run on the the contents of the div.
+        md.treeprocessors.register(FootnoteTreeprocessor(self), 'footnote', 50)
+
+        # Insert a tree-processor that will run after inline is done.
+        # In this tree-processor we want to check our duplicate footnote tracker
+        # And add additional `backrefs` to the footnote pointing back to the
+        # duplicated references.
+        md.treeprocessors.register(FootnotePostTreeprocessor(self), 'footnote-duplicate', 15)
+
+        # Insert a postprocessor after amp_substitute processor
+        md.postprocessors.register(FootnotePostprocessor(self), 'footnote', 25)
+
+    def reset(self) -> None:
+        """ Clear footnotes on reset, and prepare for distinct document. """
+        self.footnotes: OrderedDict[str, str] = OrderedDict()
+        self.unique_prefix += 1
+        self.found_refs = {}
+        self.used_refs = set()
+
+    def unique_ref(self, reference, found: bool = False):
+        """ Get a unique reference if there are duplicates. """
+        if not found:
+            return reference
+
+        original_ref = reference
+        while reference in self.used_refs:
+            ref, rest = reference.split(self.get_separator(), 1)
+            m = RE_REF_ID.match(ref)
+            if m:
+                reference = '%s%d%s%s' % (m.group(1), int(m.group(2))+1, self.get_separator(), rest)
+            else:
+                reference = '%s%d%s%s' % (ref, 2, self.get_separator(), rest)
+
+        self.used_refs.add(reference)
+        if original_ref in self.found_refs:
+            self.found_refs[original_ref] += 1
+        else:
+            self.found_refs[original_ref] = 1
+        return reference
+
+    def findFootnotesPlaceholder(self, root):
+        """ Return ElementTree Element that contains Footnote placeholder. """
+        def finder(element):
+            for child in element:
+                if child.text:
+                    if child.text.find(self.getConfig("PLACE_MARKER")) > -1:
+                        return child, element, True
+                if child.tail:
+                    if child.tail.find(self.getConfig("PLACE_MARKER")) > -1:
+                        return child, element, False
+                child_res = finder(child)
+                if child_res is not None:
+                    return child_res
+            return None
+
+        res = finder(root)
+        return res
+
+    def setFootnote(self, id, text) -> None:
+        """ Store a footnote for later retrieval. """
+        self.footnotes[id] = text
+
+    def get_separator(self):
+        """ Get the footnote separator. """
+        return self.getConfig("SEPARATOR")
+
+    def makeFootnoteId(self, id):
+        """ Return footnote link id. """
+        if self.getConfig("UNIQUE_IDS"):
+            return 'fn%s%d-%s' % (self.get_separator(), self.unique_prefix, id)
+        else:
+            return 'fn{}{}'.format(self.get_separator(), id)
+
+    def makeFootnoteRefId(self, id, found: bool = False):
+        """ Return footnote back-link id. """
+        if self.getConfig("UNIQUE_IDS"):
+            return self.unique_ref('fnref%s%d-%s' % (self.get_separator(), self.unique_prefix, id), found)
+        else:
+            return self.unique_ref('fnref{}{}'.format(self.get_separator(), id), found)
+
+    def makeFootnotesDiv(self, root):
+        """ Return `div` of footnotes as `etree` Element. """
+
+        if not list(self.footnotes.keys()):
+            return None
+
+        div = etree.Element("div")
+        div.set('class', 'footnote')
+        etree.SubElement(div, "hr")
+        ol = etree.SubElement(div, "ol")
+        surrogate_parent = etree.Element("div")
+
+        # Backward compatibility with old '%d' placeholder
+        backlink_title = self.getConfig("BACKLINK_TITLE").replace("%d", "{}")
+
+        for index, id in enumerate(self.footnotes.keys(), start=1):
+            li = etree.SubElement(ol, "li")
+            li.set("id", self.makeFootnoteId(id))
+            # Parse footnote with surrogate parent as `li` cannot be used.
+            # List block handlers have special logic to deal with `li`.
+            # When we are done parsing, we will copy everything over to `li`.
+            self.parser.parseChunk(surrogate_parent, self.footnotes[id])
+            for el in list(surrogate_parent):
+                li.append(el)
+                surrogate_parent.remove(el)
+            backlink = etree.Element("a")
+            backlink.set("href", "#" + self.makeFootnoteRefId(id))
+            backlink.set("class", "footnote-backref")
+            backlink.set(
+                "title",
+                backlink_title.format(index)
+            )
+            backlink.text = FN_BACKLINK_TEXT
+
+            if len(li):
+                node = li[-1]
+                if node.tag == "p":
+                    node.text = node.text + NBSP_PLACEHOLDER
+                    node.append(backlink)
+                else:
+                    p = etree.SubElement(li, "p")
+                    p.append(backlink)
+        return div
+
+
+class FootnoteBlockProcessor(BlockProcessor):
+    """ Find all footnote references and store for later use. """
+
+    RE = re.compile(r'^[ ]{0,3}\[\^([^\]]*)\]:[ ]*(.*)$', re.MULTILINE)
+
+    def __init__(self, footnotes):
+        super().__init__(footnotes.parser)
+        self.footnotes = footnotes
+
+    def test(self, parent, block):
+        return True
+
+    def run(self, parent, blocks):
+        """ Find, set, and remove footnote definitions. """
+        block = blocks.pop(0)
+        m = self.RE.search(block)
+        if m:
+            id = m.group(1)
+            fn_blocks = [m.group(2)]
+
+            # Handle rest of block
+            therest = block[m.end():].lstrip('\n')
+            m2 = self.RE.search(therest)
+            if m2:
+                # Another footnote exists in the rest of this block.
+                # Any content before match is continuation of this footnote, which may be lazily indented.
+                before = therest[:m2.start()].rstrip('\n')
+                fn_blocks[0] = '\n'.join([fn_blocks[0], self.detab(before)]).lstrip('\n')
+                # Add back to blocks everything from beginning of match forward for next iteration.
+                blocks.insert(0, therest[m2.start():])
+            else:
+                # All remaining lines of block are continuation of this footnote, which may be lazily indented.
+                fn_blocks[0] = '\n'.join([fn_blocks[0], self.detab(therest)]).strip('\n')
+
+                # Check for child elements in remaining blocks.
+                fn_blocks.extend(self.detectTabbed(blocks))
+
+            footnote = "\n\n".join(fn_blocks)
+            self.footnotes.setFootnote(id, footnote.rstrip())
+
+            if block[:m.start()].strip():
+                # Add any content before match back to blocks as separate block
+                blocks.insert(0, block[:m.start()].rstrip('\n'))
+            return True
+        # No match. Restore block.
+        blocks.insert(0, block)
+        return False
+
+    def detectTabbed(self, blocks) -> list[str]:
+        """ Find indented text and remove indent before further processing.
+
+        Returns:
+            A list of blocks with indentation removed.
+        """
+        fn_blocks = []
+        while blocks:
+            if blocks[0].startswith(' '*4):
+                block = blocks.pop(0)
+                # Check for new footnotes within this block and split at new footnote.
+                m = self.RE.search(block)
+                if m:
+                    # Another footnote exists in this block.
+                    # Any content before match is continuation of this footnote, which may be lazily indented.
+                    before = block[:m.start()].rstrip('\n')
+                    fn_blocks.append(self.detab(before))
+                    # Add back to blocks everything from beginning of match forward for next iteration.
+                    blocks.insert(0, block[m.start():])
+                    # End of this footnote.
+                    break
+                else:
+                    # Entire block is part of this footnote.
+                    fn_blocks.append(self.detab(block))
+            else:
+                # End of this footnote.
+                break
+        return fn_blocks
+
+    def detab(self, block):
+        """ Remove one level of indent from a block.
+
+        Preserve lazily indented blocks by only removing indent from indented lines.
+        """
+        lines = block.split('\n')
+        for i, line in enumerate(lines):
+            if line.startswith(' '*4):
+                lines[i] = line[4:]
+        return '\n'.join(lines)
+
+
+class FootnoteInlineProcessor(InlineProcessor):
+    """ `InlineProcessor` for footnote markers in a document's body text. """
+
+    def __init__(self, pattern, footnotes):
+        super().__init__(pattern)
+        self.footnotes = footnotes
+
+    def handleMatch(self, m, data):
+        id = m.group(1)
+        if id in self.footnotes.footnotes.keys():
+            sup = etree.Element("sup")
+            a = etree.SubElement(sup, "a")
+            sup.set('id', self.footnotes.makeFootnoteRefId(id, found=True))
+            a.set('href', '#' + self.footnotes.makeFootnoteId(id))
+            a.set('class', 'footnote-ref')
+            a.text = self.footnotes.getConfig("SUPERSCRIPT_TEXT").format(
+                list(self.footnotes.footnotes.keys()).index(id) + 1
+            )
+            return sup, m.start(0), m.end(0)
+        else:
+            return None, None, None
+
+
+class FootnotePostTreeprocessor(Treeprocessor):
+    """ Amend footnote div with duplicates. """
+
+    def __init__(self, footnotes):
+        self.footnotes = footnotes
+
+    def add_duplicates(self, li, duplicates) -> None:
+        """ Adjust current `li` and add the duplicates: `fnref2`, `fnref3`, etc. """
+        for link in li.iter('a'):
+            # Find the link that needs to be duplicated.
+            if link.attrib.get('class', '') == 'footnote-backref':
+                ref, rest = link.attrib['href'].split(self.footnotes.get_separator(), 1)
+                # Duplicate link the number of times we need to
+                # and point the to the appropriate references.
+                links = []
+                for index in range(2, duplicates + 1):
+                    sib_link = copy.deepcopy(link)
+                    sib_link.attrib['href'] = '%s%d%s%s' % (ref, index, self.footnotes.get_separator(), rest)
+                    links.append(sib_link)
+                    self.offset += 1
+                # Add all the new duplicate links.
+                el = list(li)[-1]
+                for link in links:
+                    el.append(link)
+                break
+
+    def get_num_duplicates(self, li):
+        """ Get the number of duplicate refs of the footnote. """
+        fn, rest = li.attrib.get('id', '').split(self.footnotes.get_separator(), 1)
+        link_id = '{}ref{}{}'.format(fn, self.footnotes.get_separator(), rest)
+        return self.footnotes.found_refs.get(link_id, 0)
+
+    def handle_duplicates(self, parent) -> None:
+        """ Find duplicate footnotes and format and add the duplicates. """
+        for li in list(parent):
+            # Check number of duplicates footnotes and insert
+            # additional links if needed.
+            count = self.get_num_duplicates(li)
+            if count > 1:
+                self.add_duplicates(li, count)
+
+    def run(self, root):
+        """ Crawl the footnote div and add missing duplicate footnotes. """
+        self.offset = 0
+        for div in root.iter('div'):
+            if div.attrib.get('class', '') == 'footnote':
+                # Footnotes should be under the first ordered list under
+                # the footnote div.  So once we find it, quit.
+                for ol in div.iter('ol'):
+                    self.handle_duplicates(ol)
+                    break
+
+
+class FootnoteTreeprocessor(Treeprocessor):
+    """ Build and append footnote div to end of document. """
+
+    def __init__(self, footnotes):
+        self.footnotes = footnotes
+
+    def run(self, root):
+        footnotesDiv = self.footnotes.makeFootnotesDiv(root)
+        if footnotesDiv is not None:
+            result = self.footnotes.findFootnotesPlaceholder(root)
+            if result:
+                child, parent, isText = result
+                ind = list(parent).index(child)
+                if isText:
+                    parent.remove(child)
+                    parent.insert(ind, footnotesDiv)
+                else:
+                    parent.insert(ind + 1, footnotesDiv)
+                    child.tail = None
+            else:
+                root.append(footnotesDiv)
+
+
+class FootnotePostprocessor(Postprocessor):
+    """ Replace placeholders with html entities. """
+    def __init__(self, footnotes):
+        self.footnotes = footnotes
+
+    def run(self, text):
+        text = text.replace(
+            FN_BACKLINK_TEXT, self.footnotes.getConfig("BACKLINK_TEXT")
+        )
+        return text.replace(NBSP_PLACEHOLDER, " ")
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    """ Return an instance of the `FootnoteExtension` """
+    return FootnoteExtension(**kwargs)

plugins/markdown_preview/markdown/extensions/legacy_attrs.py

@@ -0,0 +1,67 @@
+# Python Markdown
+
+# A Python implementation of John Gruber's Markdown.
+
+# Documentation: https://python-markdown.github.io/
+# GitHub: https://github.com/Python-Markdown/markdown/
+# PyPI: https://pypi.org/project/Markdown/
+
+# Started by Manfred Stienstra (http://www.dwerg.net/).
+# Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
+# Currently maintained by Waylan Limberg (https://github.com/waylan),
+# Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
+
+# Copyright 2007-2023 The Python Markdown Project (v. 1.7 and later)
+# Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
+# Copyright 2004 Manfred Stienstra (the original version)
+
+# License: BSD (see LICENSE.md for details).
+
+"""
+An extension to Python Markdown which implements legacy attributes.
+
+Prior to Python-Markdown version 3.0, the Markdown class had an `enable_attributes`
+keyword which was on by default and provided for attributes to be defined for elements
+using the format `{@key=value}`. This extension is provided as a replacement for
+backward compatibility. New documents should be authored using `attr_lists`. However,
+numerous documents exist which have been using the old attribute format for many
+years. This extension can be used to continue to render those documents correctly.
+"""
+
+from __future__ import annotations
+
+import re
+from markdown.treeprocessors import Treeprocessor, isString
+from markdown.extensions import Extension
+
+
+ATTR_RE = re.compile(r'\{@([^\}]*)=([^\}]*)}')  # {@id=123}
+
+
+class LegacyAttrs(Treeprocessor):
+    def run(self, doc):
+        """Find and set values of attributes ({@key=value}). """
+        for el in doc.iter():
+            alt = el.get('alt', None)
+            if alt is not None:
+                el.set('alt', self.handleAttributes(el, alt))
+            if el.text and isString(el.text):
+                el.text = self.handleAttributes(el, el.text)
+            if el.tail and isString(el.tail):
+                el.tail = self.handleAttributes(el, el.tail)
+
+    def handleAttributes(self, el, txt):
+        """ Set attributes and return text without definitions. """
+        def attributeCallback(match):
+            el.set(match.group(1), match.group(2).replace('\n', ' '))
+        return ATTR_RE.sub(attributeCallback, txt)
+
+
+class LegacyAttrExtension(Extension):
+    def extendMarkdown(self, md):
+        """ Add `LegacyAttrs` to Markdown instance. """
+        md.treeprocessors.register(LegacyAttrs(md), 'legacyattrs', 15)
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    return LegacyAttrExtension(**kwargs)

plugins/markdown_preview/markdown/extensions/legacy_em.py

@@ -0,0 +1,52 @@
+# Legacy Em Extension for Python-Markdown
+# =======================================
+
+# This extension provides legacy behavior for _connected_words_.
+
+# Copyright 2015-2018 The Python Markdown Project
+
+# License: [BSD](https://opensource.org/licenses/bsd-license.php)
+
+"""
+This extension provides legacy behavior for _connected_words_.
+"""
+
+from __future__ import annotations
+
+from . import Extension
+from ..inlinepatterns import UnderscoreProcessor, EmStrongItem, EM_STRONG2_RE, STRONG_EM2_RE
+import re
+
+# _emphasis_
+EMPHASIS_RE = r'(_)([^_]+)\1'
+
+# __strong__
+STRONG_RE = r'(_{2})(.+?)\1'
+
+# __strong_em___
+STRONG_EM_RE = r'(_)\1(?!\1)([^_]+?)\1(?!\1)(.+?)\1{3}'
+
+
+class LegacyUnderscoreProcessor(UnderscoreProcessor):
+    """Emphasis processor for handling strong and em matches inside underscores."""
+
+    PATTERNS = [
+        EmStrongItem(re.compile(EM_STRONG2_RE, re.DOTALL | re.UNICODE), 'double', 'strong,em'),
+        EmStrongItem(re.compile(STRONG_EM2_RE, re.DOTALL | re.UNICODE), 'double', 'em,strong'),
+        EmStrongItem(re.compile(STRONG_EM_RE, re.DOTALL | re.UNICODE), 'double2', 'strong,em'),
+        EmStrongItem(re.compile(STRONG_RE, re.DOTALL | re.UNICODE), 'single', 'strong'),
+        EmStrongItem(re.compile(EMPHASIS_RE, re.DOTALL | re.UNICODE), 'single', 'em')
+    ]
+
+
+class LegacyEmExtension(Extension):
+    """ Add legacy_em extension to Markdown class."""
+
+    def extendMarkdown(self, md):
+        """ Modify inline patterns. """
+        md.inlinePatterns.register(LegacyUnderscoreProcessor(r'_'), 'em_strong2', 50)
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    """ Return an instance of the `LegacyEmExtension` """
+    return LegacyEmExtension(**kwargs)

plugins/markdown_preview/markdown/extensions/md_in_html.py

@@ -0,0 +1,372 @@
+# Python-Markdown Markdown in HTML Extension
+# ===============================
+
+# An implementation of [PHP Markdown Extra](http://michelf.com/projects/php-markdown/extra/)'s
+# parsing of Markdown syntax in raw HTML.
+
+# See https://Python-Markdown.github.io/extensions/raw_html
+# for documentation.
+
+# Copyright The Python Markdown Project
+
+# License: [BSD](https://opensource.org/licenses/bsd-license.php)
+
+"""
+An implementation of [PHP Markdown Extra](http://michelf.com/projects/php-markdown/extra/)'s
+parsing of Markdown syntax in raw HTML.
+
+See the [documentation](https://Python-Markdown.github.io/extensions/raw_html)
+for details.
+"""
+
+from __future__ import annotations
+
+from . import Extension
+from ..blockprocessors import BlockProcessor
+from ..preprocessors import Preprocessor
+from ..postprocessors import RawHtmlPostprocessor
+from .. import util
+from ..htmlparser import HTMLExtractor, blank_line_re
+import xml.etree.ElementTree as etree
+
+
+class HTMLExtractorExtra(HTMLExtractor):
+    """
+    Override `HTMLExtractor` and create `etree` `Elements` for any elements which should have content parsed as
+    Markdown.
+    """
+
+    def __init__(self, md, *args, **kwargs):
+        # All block-level tags.
+        self.block_level_tags = set(md.block_level_elements.copy())
+        # Block-level tags in which the content only gets span level parsing
+        self.span_tags = set(
+            ['address', 'dd', 'dt', 'h1', 'h2', 'h3', 'h4', 'h5', 'h6', 'legend', 'li', 'p', 'summary', 'td', 'th']
+        )
+        # Block-level tags which never get their content parsed.
+        self.raw_tags = set(['canvas', 'math', 'option', 'pre', 'script', 'style', 'textarea'])
+
+        super().__init__(md, *args, **kwargs)
+
+        # Block-level tags in which the content gets parsed as blocks
+        self.block_tags = set(self.block_level_tags) - (self.span_tags | self.raw_tags | self.empty_tags)
+        self.span_and_blocks_tags = self.block_tags | self.span_tags
+
+    def reset(self):
+        """Reset this instance.  Loses all unprocessed data."""
+        self.mdstack = []  # When markdown=1, stack contains a list of tags
+        self.treebuilder = etree.TreeBuilder()
+        self.mdstate = []  # one of 'block', 'span', 'off', or None
+        super().reset()
+
+    def close(self):
+        """Handle any buffered data."""
+        super().close()
+        # Handle any unclosed tags.
+        if self.mdstack:
+            # Close the outermost parent. `handle_endtag` will close all unclosed children.
+            self.handle_endtag(self.mdstack[0])
+
+    def get_element(self):
+        """ Return element from `treebuilder` and reset `treebuilder` for later use. """
+        element = self.treebuilder.close()
+        self.treebuilder = etree.TreeBuilder()
+        return element
+
+    def get_state(self, tag, attrs):
+        """ Return state from tag and `markdown` attribute. One of 'block', 'span', or 'off'. """
+        md_attr = attrs.get('markdown', '0')
+        if md_attr == 'markdown':
+            # `<tag markdown>` is the same as `<tag markdown='1'>`.
+            md_attr = '1'
+        parent_state = self.mdstate[-1] if self.mdstate else None
+        if parent_state == 'off' or (parent_state == 'span' and md_attr != '0'):
+            # Only use the parent state if it is more restrictive than the markdown attribute.
+            md_attr = parent_state
+        if ((md_attr == '1' and tag in self.block_tags) or
+                (md_attr == 'block' and tag in self.span_and_blocks_tags)):
+            return 'block'
+        elif ((md_attr == '1' and tag in self.span_tags) or
+              (md_attr == 'span' and tag in self.span_and_blocks_tags)):
+            return 'span'
+        elif tag in self.block_level_tags:
+            return 'off'
+        else:  # pragma: no cover
+            return None
+
+    def handle_starttag(self, tag, attrs):
+        # Handle tags that should always be empty and do not specify a closing tag
+        if tag in self.empty_tags and (self.at_line_start() or self.intail):
+            attrs = {key: value if value is not None else key for key, value in attrs}
+            if "markdown" in attrs:
+                attrs.pop('markdown')
+                element = etree.Element(tag, attrs)
+                data = etree.tostring(element, encoding='unicode', method='html')
+            else:
+                data = self.get_starttag_text()
+            self.handle_empty_tag(data, True)
+            return
+
+        if tag in self.block_level_tags and (self.at_line_start() or self.intail):
+            # Valueless attribute (ex: `<tag checked>`) results in `[('checked', None)]`.
+            # Convert to `{'checked': 'checked'}`.
+            attrs = {key: value if value is not None else key for key, value in attrs}
+            state = self.get_state(tag, attrs)
+            if self.inraw or (state in [None, 'off'] and not self.mdstack):
+                # fall back to default behavior
+                attrs.pop('markdown', None)
+                super().handle_starttag(tag, attrs)
+            else:
+                if 'p' in self.mdstack and tag in self.block_level_tags:
+                    # Close unclosed 'p' tag
+                    self.handle_endtag('p')
+                self.mdstate.append(state)
+                self.mdstack.append(tag)
+                attrs['markdown'] = state
+                self.treebuilder.start(tag, attrs)
+        else:
+            # Span level tag
+            if self.inraw:
+                super().handle_starttag(tag, attrs)
+            else:
+                text = self.get_starttag_text()
+                if self.mdstate and self.mdstate[-1] == "off":
+                    self.handle_data(self.md.htmlStash.store(text))
+                else:
+                    self.handle_data(text)
+                if tag in self.CDATA_CONTENT_ELEMENTS:
+                    # This is presumably a standalone tag in a code span (see #1036).
+                    self.clear_cdata_mode()
+
+    def handle_endtag(self, tag):
+        if tag in self.block_level_tags:
+            if self.inraw:
+                super().handle_endtag(tag)
+            elif tag in self.mdstack:
+                # Close element and any unclosed children
+                while self.mdstack:
+                    item = self.mdstack.pop()
+                    self.mdstate.pop()
+                    self.treebuilder.end(item)
+                    if item == tag:
+                        break
+                if not self.mdstack:
+                    # Last item in stack is closed. Stash it
+                    element = self.get_element()
+                    # Get last entry to see if it ends in newlines
+                    # If it is an element, assume there is no newlines
+                    item = self.cleandoc[-1] if self.cleandoc else ''
+                    # If we only have one newline before block element, add another
+                    if not item.endswith('\n\n') and item.endswith('\n'):
+                        self.cleandoc.append('\n')
+                    self.cleandoc.append(self.md.htmlStash.store(element))
+                    self.cleandoc.append('\n\n')
+                    self.state = []
+                    # Check if element has a tail
+                    if not blank_line_re.match(
+                            self.rawdata[self.line_offset + self.offset + len(self.get_endtag_text(tag)):]):
+                        # More content exists after `endtag`.
+                        self.intail = True
+            else:
+                # Treat orphan closing tag as a span level tag.
+                text = self.get_endtag_text(tag)
+                if self.mdstate and self.mdstate[-1] == "off":
+                    self.handle_data(self.md.htmlStash.store(text))
+                else:
+                    self.handle_data(text)
+        else:
+            # Span level tag
+            if self.inraw:
+                super().handle_endtag(tag)
+            else:
+                text = self.get_endtag_text(tag)
+                if self.mdstate and self.mdstate[-1] == "off":
+                    self.handle_data(self.md.htmlStash.store(text))
+                else:
+                    self.handle_data(text)
+
+    def handle_startendtag(self, tag, attrs):
+        if tag in self.empty_tags:
+            attrs = {key: value if value is not None else key for key, value in attrs}
+            if "markdown" in attrs:
+                attrs.pop('markdown')
+                element = etree.Element(tag, attrs)
+                data = etree.tostring(element, encoding='unicode', method='html')
+            else:
+                data = self.get_starttag_text()
+        else:
+            data = self.get_starttag_text()
+        self.handle_empty_tag(data, is_block=self.md.is_block_level(tag))
+
+    def handle_data(self, data):
+        if self.intail and '\n' in data:
+            self.intail = False
+        if self.inraw or not self.mdstack:
+            super().handle_data(data)
+        else:
+            self.treebuilder.data(data)
+
+    def handle_empty_tag(self, data, is_block):
+        if self.inraw or not self.mdstack:
+            super().handle_empty_tag(data, is_block)
+        else:
+            if self.at_line_start() and is_block:
+                self.handle_data('\n' + self.md.htmlStash.store(data) + '\n\n')
+            else:
+                self.handle_data(self.md.htmlStash.store(data))
+
+    def parse_pi(self, i):
+        if self.at_line_start() or self.intail or self.mdstack:
+            # The same override exists in `HTMLExtractor` without the check
+            # for `mdstack`. Therefore, use parent of `HTMLExtractor` instead.
+            return super(HTMLExtractor, self).parse_pi(i)
+        # This is not the beginning of a raw block so treat as plain data
+        # and avoid consuming any tags which may follow (see #1066).
+        self.handle_data('<?')
+        return i + 2
+
+    def parse_html_declaration(self, i):
+        if self.at_line_start() or self.intail or self.mdstack:
+            # The same override exists in `HTMLExtractor` without the check
+            # for `mdstack`. Therefore, use parent of `HTMLExtractor` instead.
+            return super(HTMLExtractor, self).parse_html_declaration(i)
+        # This is not the beginning of a raw block so treat as plain data
+        # and avoid consuming any tags which may follow (see #1066).
+        self.handle_data('<!')
+        return i + 2
+
+
+class HtmlBlockPreprocessor(Preprocessor):
+    """Remove html blocks from the text and store them for later retrieval."""
+
+    def run(self, lines):
+        source = '\n'.join(lines)
+        parser = HTMLExtractorExtra(self.md)
+        parser.feed(source)
+        parser.close()
+        return ''.join(parser.cleandoc).split('\n')
+
+
+class MarkdownInHtmlProcessor(BlockProcessor):
+    """Process Markdown Inside HTML Blocks which have been stored in the `HtmlStash`."""
+
+    def test(self, parent, block):
+        # Always return True. `run` will return `False` it not a valid match.
+        return True
+
+    def parse_element_content(self, element):
+        """
+        Recursively parse the text content of an `etree` Element as Markdown.
+
+        Any block level elements generated from the Markdown will be inserted as children of the element in place
+        of the text content. All `markdown` attributes are removed. For any elements in which Markdown parsing has
+        been disabled, the text content of it and its children are wrapped in an `AtomicString`.
+        """
+
+        md_attr = element.attrib.pop('markdown', 'off')
+
+        if md_attr == 'block':
+            # Parse content as block level
+            # The order in which the different parts are parsed (text, children, tails) is important here as the
+            # order of elements needs to be preserved. We can't be inserting items at a later point in the current
+            # iteration as we don't want to do raw processing on elements created from parsing Markdown text (for
+            # example). Therefore, the order of operations is children, tails, text.
+
+            # Recursively parse existing children from raw HTML
+            for child in list(element):
+                self.parse_element_content(child)
+
+            # Parse Markdown text in tail of children. Do this separate to avoid raw HTML parsing.
+            # Save the position of each item to be inserted later in reverse.
+            tails = []
+            for pos, child in enumerate(element):
+                if child.tail:
+                    block = child.tail.rstrip('\n')
+                    child.tail = ''
+                    # Use a dummy placeholder element.
+                    dummy = etree.Element('div')
+                    self.parser.parseBlocks(dummy, block.split('\n\n'))
+                    children = list(dummy)
+                    children.reverse()
+                    tails.append((pos + 1, children))
+
+            # Insert the elements created from the tails in reverse.
+            tails.reverse()
+            for pos, tail in tails:
+                for item in tail:
+                    element.insert(pos, item)
+
+            # Parse Markdown text content. Do this last to avoid raw HTML parsing.
+            if element.text:
+                block = element.text.rstrip('\n')
+                element.text = ''
+                # Use a dummy placeholder element as the content needs to get inserted before existing children.
+                dummy = etree.Element('div')
+                self.parser.parseBlocks(dummy, block.split('\n\n'))
+                children = list(dummy)
+                children.reverse()
+                for child in children:
+                    element.insert(0, child)
+
+        elif md_attr == 'span':
+            # Span level parsing will be handled by inline processors.
+            # Walk children here to remove any `markdown` attributes.
+            for child in list(element):
+                self.parse_element_content(child)
+
+        else:
+            # Disable inline parsing for everything else
+            if element.text is None:
+                element.text = ''
+            element.text = util.AtomicString(element.text)
+            for child in list(element):
+                self.parse_element_content(child)
+                if child.tail:
+                    child.tail = util.AtomicString(child.tail)
+
+    def run(self, parent, blocks):
+        m = util.HTML_PLACEHOLDER_RE.match(blocks[0])
+        if m:
+            index = int(m.group(1))
+            element = self.parser.md.htmlStash.rawHtmlBlocks[index]
+            if isinstance(element, etree.Element):
+                # We have a matched element. Process it.
+                blocks.pop(0)
+                self.parse_element_content(element)
+                parent.append(element)
+                # Cleanup stash. Replace element with empty string to avoid confusing postprocessor.
+                self.parser.md.htmlStash.rawHtmlBlocks.pop(index)
+                self.parser.md.htmlStash.rawHtmlBlocks.insert(index, '')
+                # Confirm the match to the `blockparser`.
+                return True
+        # No match found.
+        return False
+
+
+class MarkdownInHTMLPostprocessor(RawHtmlPostprocessor):
+    def stash_to_string(self, text):
+        """ Override default to handle any `etree` elements still in the stash. """
+        if isinstance(text, etree.Element):
+            return self.md.serializer(text)
+        else:
+            return str(text)
+
+
+class MarkdownInHtmlExtension(Extension):
+    """Add Markdown parsing in HTML to Markdown class."""
+
+    def extendMarkdown(self, md):
+        """ Register extension instances. """
+
+        # Replace raw HTML preprocessor
+        md.preprocessors.register(HtmlBlockPreprocessor(md), 'html_block', 20)
+        # Add `blockprocessor` which handles the placeholders for `etree` elements
+        md.parser.blockprocessors.register(
+            MarkdownInHtmlProcessor(md.parser), 'markdown_block', 105
+        )
+        # Replace raw HTML postprocessor
+        md.postprocessors.register(MarkdownInHTMLPostprocessor(md), 'raw_html', 30)
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    return MarkdownInHtmlExtension(**kwargs)

plugins/markdown_preview/markdown/extensions/meta.py

@@ -0,0 +1,85 @@
+# Meta Data Extension for Python-Markdown
+# =======================================
+
+# This extension adds Meta Data handling to markdown.
+
+# See https://Python-Markdown.github.io/extensions/meta_data
+# for documentation.
+
+# Original code Copyright 2007-2008 [Waylan Limberg](http://achinghead.com).
+
+# All changes Copyright 2008-2014 The Python Markdown Project
+
+# License: [BSD](https://opensource.org/licenses/bsd-license.php)
+
+"""
+This extension adds Meta Data handling to markdown.
+
+See the [documentation](https://Python-Markdown.github.io/extensions/meta_data)
+for details.
+"""
+
+from __future__ import annotations
+
+from . import Extension
+from ..preprocessors import Preprocessor
+import re
+import logging
+
+log = logging.getLogger('MARKDOWN')
+
+# Global Vars
+META_RE = re.compile(r'^[ ]{0,3}(?P<key>[A-Za-z0-9_-]+):\s*(?P<value>.*)')
+META_MORE_RE = re.compile(r'^[ ]{4,}(?P<value>.*)')
+BEGIN_RE = re.compile(r'^-{3}(\s.*)?')
+END_RE = re.compile(r'^(-{3}|\.{3})(\s.*)?')
+
+
+class MetaExtension (Extension):
+    """ Meta-Data extension for Python-Markdown. """
+
+    def extendMarkdown(self, md):
+        """ Add `MetaPreprocessor` to Markdown instance. """
+        md.registerExtension(self)
+        self.md = md
+        md.preprocessors.register(MetaPreprocessor(md), 'meta', 27)
+
+    def reset(self) -> None:
+        self.md.Meta = {}
+
+
+class MetaPreprocessor(Preprocessor):
+    """ Get Meta-Data. """
+
+    def run(self, lines):
+        """ Parse Meta-Data and store in Markdown.Meta. """
+        meta = {}
+        key = None
+        if lines and BEGIN_RE.match(lines[0]):
+            lines.pop(0)
+        while lines:
+            line = lines.pop(0)
+            m1 = META_RE.match(line)
+            if line.strip() == '' or END_RE.match(line):
+                break  # blank line or end of YAML header - done
+            if m1:
+                key = m1.group('key').lower().strip()
+                value = m1.group('value').strip()
+                try:
+                    meta[key].append(value)
+                except KeyError:
+                    meta[key] = [value]
+            else:
+                m2 = META_MORE_RE.match(line)
+                if m2 and key:
+                    # Add another line to existing key
+                    meta[key].append(m2.group('value').strip())
+                else:
+                    lines.insert(0, line)
+                    break  # no meta data - done
+        self.md.Meta = meta
+        return lines
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    return MetaExtension(**kwargs)

plugins/markdown_preview/markdown/extensions/nl2br.py

@@ -0,0 +1,41 @@
+# `NL2BR` Extension
+# ===============
+
+# A Python-Markdown extension to treat newlines as hard breaks; like
+# GitHub-flavored Markdown does.
+
+# See https://Python-Markdown.github.io/extensions/nl2br
+# for documentation.
+
+# Original code Copyright 2011 [Brian Neal](https://deathofagremmie.com/)
+
+# All changes Copyright 2011-2014 The Python Markdown Project
+
+# License: [BSD](https://opensource.org/licenses/bsd-license.php)
+
+"""
+A Python-Markdown extension to treat newlines as hard breaks; like
+GitHub-flavored Markdown does.
+
+See the [documentation](https://Python-Markdown.github.io/extensions/nl2br)
+for details.
+"""
+
+from __future__ import annotations
+
+from . import Extension
+from ..inlinepatterns import SubstituteTagInlineProcessor
+
+BR_RE = r'\n'
+
+
+class Nl2BrExtension(Extension):
+
+    def extendMarkdown(self, md):
+        """ Add a `SubstituteTagInlineProcessor` to Markdown. """
+        br_tag = SubstituteTagInlineProcessor(BR_RE, 'br')
+        md.inlinePatterns.register(br_tag, 'nl', 5)
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    return Nl2BrExtension(**kwargs)

plugins/markdown_preview/markdown/extensions/sane_lists.py

@@ -0,0 +1,65 @@
+# Sane List Extension for Python-Markdown
+# =======================================
+
+# Modify the behavior of Lists in Python-Markdown to act in a sane manor.
+
+# See https://Python-Markdown.github.io/extensions/sane_lists
+# for documentation.
+
+# Original code Copyright 2011 [Waylan Limberg](http://achinghead.com)
+
+# All changes Copyright 2011-2014 The Python Markdown Project
+
+# License: [BSD](https://opensource.org/licenses/bsd-license.php)
+
+"""
+Modify the behavior of Lists in Python-Markdown to act in a sane manor.
+
+See [documentation](https://Python-Markdown.github.io/extensions/sane_lists)
+for details.
+"""
+
+from __future__ import annotations
+
+from . import Extension
+from ..blockprocessors import OListProcessor, UListProcessor
+import re
+
+
+class SaneOListProcessor(OListProcessor):
+    """ Override `SIBLING_TAGS` to not include `ul` and set `LAZY_OL` to `False`. """
+
+    SIBLING_TAGS = ['ol']
+    """ Exclude `ul` from list of siblings. """
+    LAZY_OL = False
+    """ Disable lazy list behavior. """
+
+    def __init__(self, parser):
+        super().__init__(parser)
+        self.CHILD_RE = re.compile(r'^[ ]{0,%d}((\d+\.))[ ]+(.*)' %
+                                   (self.tab_length - 1))
+
+
+class SaneUListProcessor(UListProcessor):
+    """ Override `SIBLING_TAGS` to not include `ol`. """
+
+    SIBLING_TAGS = ['ul']
+    """ Exclude `ol` from list of siblings. """
+
+    def __init__(self, parser):
+        super().__init__(parser)
+        self.CHILD_RE = re.compile(r'^[ ]{0,%d}(([*+-]))[ ]+(.*)' %
+                                   (self.tab_length - 1))
+
+
+class SaneListExtension(Extension):
+    """ Add sane lists to Markdown. """
+
+    def extendMarkdown(self, md):
+        """ Override existing Processors. """
+        md.parser.blockprocessors.register(SaneOListProcessor(md.parser), 'olist', 40)
+        md.parser.blockprocessors.register(SaneUListProcessor(md.parser), 'ulist', 30)
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    return SaneListExtension(**kwargs)

plugins/markdown_preview/markdown/extensions/smarty.py

@@ -0,0 +1,265 @@
+# Smarty extension for Python-Markdown
+# ====================================
+
+# Adds conversion of ASCII dashes, quotes and ellipses to their HTML
+# entity equivalents.
+
+# See https://Python-Markdown.github.io/extensions/smarty
+# for documentation.
+
+# Author: 2013, Dmitry Shachnev <mitya57@gmail.com>
+
+# All changes Copyright 2013-2014 The Python Markdown Project
+
+# License: [BSD](https://opensource.org/licenses/bsd-license.php)
+
+# SmartyPants license:
+
+#    Copyright (c) 2003 John Gruber <https://daringfireball.net/>
+#    All rights reserved.
+
+#    Redistribution and use in source and binary forms, with or without
+#    modification, are permitted provided that the following conditions are
+#    met:
+
+#    *  Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+
+#    *  Redistributions in binary form must reproduce the above copyright
+#       notice, this list of conditions and the following disclaimer in
+#       the documentation and/or other materials provided with the
+#       distribution.
+
+#    *  Neither the name "SmartyPants" nor the names of its contributors
+#       may be used to endorse or promote products derived from this
+#       software without specific prior written permission.
+
+#    This software is provided by the copyright holders and contributors "as
+#    is" and any express or implied warranties, including, but not limited
+#    to, the implied warranties of merchantability and fitness for a
+#    particular purpose are disclaimed. In no event shall the copyright
+#    owner or contributors be liable for any direct, indirect, incidental,
+#    special, exemplary, or consequential damages (including, but not
+#    limited to, procurement of substitute goods or services; loss of use,
+#    data, or profits; or business interruption) however caused and on any
+#    theory of liability, whether in contract, strict liability, or tort
+#    (including negligence or otherwise) arising in any way out of the use
+#    of this software, even if advised of the possibility of such damage.
+
+
+# `smartypants.py` license:
+
+#    `smartypants.py` is a derivative work of SmartyPants.
+#    Copyright (c) 2004, 2007 Chad Miller <http://web.chad.org/>
+
+#    Redistribution and use in source and binary forms, with or without
+#    modification, are permitted provided that the following conditions are
+#    met:
+
+#    *  Redistributions of source code must retain the above copyright
+#       notice, this list of conditions and the following disclaimer.
+
+#    *  Redistributions in binary form must reproduce the above copyright
+#       notice, this list of conditions and the following disclaimer in
+#       the documentation and/or other materials provided with the
+#       distribution.
+
+#    This software is provided by the copyright holders and contributors "as
+#    is" and any express or implied warranties, including, but not limited
+#    to, the implied warranties of merchantability and fitness for a
+#    particular purpose are disclaimed. In no event shall the copyright
+#    owner or contributors be liable for any direct, indirect, incidental,
+#    special, exemplary, or consequential damages (including, but not
+#    limited to, procurement of substitute goods or services; loss of use,
+#    data, or profits; or business interruption) however caused and on any
+#    theory of liability, whether in contract, strict liability, or tort
+#    (including negligence or otherwise) arising in any way out of the use
+#    of this software, even if advised of the possibility of such damage.
+
+"""
+Adds conversion of ASCII dashes, quotes and ellipses to their HTML
+entity equivalents.
+
+See the [documentation](https://Python-Markdown.github.io/extensions/smarty)
+for details.
+"""
+
+from __future__ import annotations
+
+from . import Extension
+from ..inlinepatterns import HtmlInlineProcessor, HTML_RE
+from ..treeprocessors import InlineProcessor
+from ..util import Registry
+
+
+# Constants for quote education.
+punctClass = r"""[!"#\$\%'()*+,-.\/:;<=>?\@\[\\\]\^_`{|}~]"""
+endOfWordClass = r"[\s.,;:!?)]"
+closeClass = r"[^\ \t\r\n\[\{\(\-\u0002\u0003]"
+
+openingQuotesBase = (
+    r'(\s'               # a  whitespace char
+    r'|&nbsp;'           # or a non-breaking space entity
+    r'|--'               # or dashes
+    r'|–|—'              # or Unicode
+    r'|&[mn]dash;'       # or named dash entities
+    r'|&#8211;|&#8212;'  # or decimal entities
+    r')'
+)
+
+substitutions = {
+    'mdash': '&mdash;',
+    'ndash': '&ndash;',
+    'ellipsis': '&hellip;',
+    'left-angle-quote': '&laquo;',
+    'right-angle-quote': '&raquo;',
+    'left-single-quote': '&lsquo;',
+    'right-single-quote': '&rsquo;',
+    'left-double-quote': '&ldquo;',
+    'right-double-quote': '&rdquo;',
+}
+
+
+# Special case if the very first character is a quote
+# followed by punctuation at a non-word-break. Close the quotes by brute force:
+singleQuoteStartRe = r"^'(?=%s\B)" % punctClass
+doubleQuoteStartRe = r'^"(?=%s\B)' % punctClass
+
+# Special case for double sets of quotes, e.g.:
+#   <p>He said, "'Quoted' words in a larger quote."</p>
+doubleQuoteSetsRe = r""""'(?=\w)"""
+singleQuoteSetsRe = r"""'"(?=\w)"""
+
+# Special case for decade abbreviations (the '80s):
+decadeAbbrRe = r"(?<!\w)'(?=\d{2}s)"
+
+# Get most opening double quotes:
+openingDoubleQuotesRegex = r'%s"(?=\w)' % openingQuotesBase
+
+# Double closing quotes:
+closingDoubleQuotesRegex = r'"(?=\s)'
+closingDoubleQuotesRegex2 = '(?<=%s)"' % closeClass
+
+# Get most opening single quotes:
+openingSingleQuotesRegex = r"%s'(?=\w)" % openingQuotesBase
+
+# Single closing quotes:
+closingSingleQuotesRegex = r"(?<=%s)'(?!\s|s\b|\d)" % closeClass
+closingSingleQuotesRegex2 = r"'(\s|s\b)"
+
+# All remaining quotes should be opening ones
+remainingSingleQuotesRegex = r"'"
+remainingDoubleQuotesRegex = r'"'
+
+HTML_STRICT_RE = HTML_RE + r'(?!\>)'
+
+
+class SubstituteTextPattern(HtmlInlineProcessor):
+    def __init__(self, pattern, replace, md):
+        """ Replaces matches with some text. """
+        HtmlInlineProcessor.__init__(self, pattern)
+        self.replace = replace
+        self.md = md
+
+    def handleMatch(self, m, data):
+        result = ''
+        for part in self.replace:
+            if isinstance(part, int):
+                result += m.group(part)
+            else:
+                result += self.md.htmlStash.store(part)
+        return result, m.start(0), m.end(0)
+
+
+class SmartyExtension(Extension):
+    """ Add Smarty to Markdown. """
+    def __init__(self, **kwargs):
+        self.config = {
+            'smart_quotes': [True, 'Educate quotes'],
+            'smart_angled_quotes': [False, 'Educate angled quotes'],
+            'smart_dashes': [True, 'Educate dashes'],
+            'smart_ellipses': [True, 'Educate ellipses'],
+            'substitutions': [{}, 'Overwrite default substitutions'],
+        }
+        """ Default configuration options. """
+        super().__init__(**kwargs)
+        self.substitutions = dict(substitutions)
+        self.substitutions.update(self.getConfig('substitutions', default={}))
+
+    def _addPatterns(self, md, patterns, serie, priority):
+        for ind, pattern in enumerate(patterns):
+            pattern += (md,)
+            pattern = SubstituteTextPattern(*pattern)
+            name = 'smarty-%s-%d' % (serie, ind)
+            self.inlinePatterns.register(pattern, name, priority-ind)
+
+    def educateDashes(self, md) -> None:
+        emDashesPattern = SubstituteTextPattern(
+            r'(?<!-)---(?!-)', (self.substitutions['mdash'],), md
+        )
+        enDashesPattern = SubstituteTextPattern(
+            r'(?<!-)--(?!-)', (self.substitutions['ndash'],), md
+        )
+        self.inlinePatterns.register(emDashesPattern, 'smarty-em-dashes', 50)
+        self.inlinePatterns.register(enDashesPattern, 'smarty-en-dashes', 45)
+
+    def educateEllipses(self, md) -> None:
+        ellipsesPattern = SubstituteTextPattern(
+            r'(?<!\.)\.{3}(?!\.)', (self.substitutions['ellipsis'],), md
+        )
+        self.inlinePatterns.register(ellipsesPattern, 'smarty-ellipses', 10)
+
+    def educateAngledQuotes(self, md) -> None:
+        leftAngledQuotePattern = SubstituteTextPattern(
+            r'\<\<', (self.substitutions['left-angle-quote'],), md
+        )
+        rightAngledQuotePattern = SubstituteTextPattern(
+            r'\>\>', (self.substitutions['right-angle-quote'],), md
+        )
+        self.inlinePatterns.register(leftAngledQuotePattern, 'smarty-left-angle-quotes', 40)
+        self.inlinePatterns.register(rightAngledQuotePattern, 'smarty-right-angle-quotes', 35)
+
+    def educateQuotes(self, md) -> None:
+        lsquo = self.substitutions['left-single-quote']
+        rsquo = self.substitutions['right-single-quote']
+        ldquo = self.substitutions['left-double-quote']
+        rdquo = self.substitutions['right-double-quote']
+        patterns = (
+            (singleQuoteStartRe, (rsquo,)),
+            (doubleQuoteStartRe, (rdquo,)),
+            (doubleQuoteSetsRe, (ldquo + lsquo,)),
+            (singleQuoteSetsRe, (lsquo + ldquo,)),
+            (decadeAbbrRe, (rsquo,)),
+            (openingSingleQuotesRegex, (1, lsquo)),
+            (closingSingleQuotesRegex, (rsquo,)),
+            (closingSingleQuotesRegex2, (rsquo, 1)),
+            (remainingSingleQuotesRegex, (lsquo,)),
+            (openingDoubleQuotesRegex, (1, ldquo)),
+            (closingDoubleQuotesRegex, (rdquo,)),
+            (closingDoubleQuotesRegex2, (rdquo,)),
+            (remainingDoubleQuotesRegex, (ldquo,))
+        )
+        self._addPatterns(md, patterns, 'quotes', 30)
+
+    def extendMarkdown(self, md):
+        configs = self.getConfigs()
+        self.inlinePatterns: Registry[HtmlInlineProcessor] = Registry()
+        if configs['smart_ellipses']:
+            self.educateEllipses(md)
+        if configs['smart_quotes']:
+            self.educateQuotes(md)
+        if configs['smart_angled_quotes']:
+            self.educateAngledQuotes(md)
+            # Override `HTML_RE` from `inlinepatterns.py` so that it does not
+            # process tags with duplicate closing quotes.
+            md.inlinePatterns.register(HtmlInlineProcessor(HTML_STRICT_RE, md), 'html', 90)
+        if configs['smart_dashes']:
+            self.educateDashes(md)
+        inlineProcessor = InlineProcessor(md)
+        inlineProcessor.inlinePatterns = self.inlinePatterns
+        md.treeprocessors.register(inlineProcessor, 'smarty', 2)
+        md.ESCAPED_CHARS.extend(['"', "'"])
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    return SmartyExtension(**kwargs)

plugins/markdown_preview/markdown/extensions/tables.py

@@ -0,0 +1,243 @@
+# Tables Extension for Python-Markdown
+# ====================================
+
+# Added parsing of tables to Python-Markdown.
+
+# See https://Python-Markdown.github.io/extensions/tables
+# for documentation.
+
+# Original code Copyright 2009 [Waylan Limberg](http://achinghead.com)
+
+# All changes Copyright 2008-2014 The Python Markdown Project
+
+# License: [BSD](https://opensource.org/licenses/bsd-license.php)
+
+"""
+Added parsing of tables to Python-Markdown.
+
+See the [documentation](https://Python-Markdown.github.io/extensions/tables)
+for details.
+"""
+
+from __future__ import annotations
+
+from . import Extension
+from ..blockprocessors import BlockProcessor
+import xml.etree.ElementTree as etree
+import re
+PIPE_NONE = 0
+PIPE_LEFT = 1
+PIPE_RIGHT = 2
+
+
+class TableProcessor(BlockProcessor):
+    """ Process Tables. """
+
+    RE_CODE_PIPES = re.compile(r'(?:(\\\\)|(\\`+)|(`+)|(\\\|)|(\|))')
+    RE_END_BORDER = re.compile(r'(?<!\\)(?:\\\\)*\|$')
+
+    def __init__(self, parser, config):
+        self.border = False
+        self.separator = ''
+        self.config = config
+
+        super().__init__(parser)
+
+    def test(self, parent, block):
+        """
+        Ensure first two rows (column header and separator row) are valid table rows.
+
+        Keep border check and separator row do avoid repeating the work.
+        """
+        is_table = False
+        rows = [row.strip(' ') for row in block.split('\n')]
+        if len(rows) > 1:
+            header0 = rows[0]
+            self.border = PIPE_NONE
+            if header0.startswith('|'):
+                self.border |= PIPE_LEFT
+            if self.RE_END_BORDER.search(header0) is not None:
+                self.border |= PIPE_RIGHT
+            row = self._split_row(header0)
+            row0_len = len(row)
+            is_table = row0_len > 1
+
+            # Each row in a single column table needs at least one pipe.
+            if not is_table and row0_len == 1 and self.border:
+                for index in range(1, len(rows)):
+                    is_table = rows[index].startswith('|')
+                    if not is_table:
+                        is_table = self.RE_END_BORDER.search(rows[index]) is not None
+                    if not is_table:
+                        break
+
+            if is_table:
+                row = self._split_row(rows[1])
+                is_table = (len(row) == row0_len) and set(''.join(row)) <= set('|:- ')
+                if is_table:
+                    self.separator = row
+
+        return is_table
+
+    def run(self, parent, blocks):
+        """ Parse a table block and build table. """
+        block = blocks.pop(0).split('\n')
+        header = block[0].strip(' ')
+        rows = [] if len(block) < 3 else block[2:]
+
+        # Get alignment of columns
+        align = []
+        for c in self.separator:
+            c = c.strip(' ')
+            if c.startswith(':') and c.endswith(':'):
+                align.append('center')
+            elif c.startswith(':'):
+                align.append('left')
+            elif c.endswith(':'):
+                align.append('right')
+            else:
+                align.append(None)
+
+        # Build table
+        table = etree.SubElement(parent, 'table')
+        thead = etree.SubElement(table, 'thead')
+        self._build_row(header, thead, align)
+        tbody = etree.SubElement(table, 'tbody')
+        if len(rows) == 0:
+            # Handle empty table
+            self._build_empty_row(tbody, align)
+        else:
+            for row in rows:
+                self._build_row(row.strip(' '), tbody, align)
+
+    def _build_empty_row(self, parent, align):
+        """Build an empty row."""
+        tr = etree.SubElement(parent, 'tr')
+        count = len(align)
+        while count:
+            etree.SubElement(tr, 'td')
+            count -= 1
+
+    def _build_row(self, row, parent, align):
+        """ Given a row of text, build table cells. """
+        tr = etree.SubElement(parent, 'tr')
+        tag = 'td'
+        if parent.tag == 'thead':
+            tag = 'th'
+        cells = self._split_row(row)
+        # We use align here rather than cells to ensure every row
+        # contains the same number of columns.
+        for i, a in enumerate(align):
+            c = etree.SubElement(tr, tag)
+            try:
+                c.text = cells[i].strip(' ')
+            except IndexError:  # pragma: no cover
+                c.text = ""
+            if a:
+                if self.config['use_align_attribute']:
+                    c.set('align', a)
+                else:
+                    c.set('style', f'text-align: {a};')
+
+    def _split_row(self, row):
+        """ split a row of text into list of cells. """
+        if self.border:
+            if row.startswith('|'):
+                row = row[1:]
+            row = self.RE_END_BORDER.sub('', row)
+        return self._split(row)
+
+    def _split(self, row):
+        """ split a row of text with some code into a list of cells. """
+        elements = []
+        pipes = []
+        tics = []
+        tic_points = []
+        tic_region = []
+        good_pipes = []
+
+        # Parse row
+        # Throw out \\, and \|
+        for m in self.RE_CODE_PIPES.finditer(row):
+            # Store ` data (len, start_pos, end_pos)
+            if m.group(2):
+                # \`+
+                # Store length of each tic group: subtract \
+                tics.append(len(m.group(2)) - 1)
+                # Store start of group, end of group, and escape length
+                tic_points.append((m.start(2), m.end(2) - 1, 1))
+            elif m.group(3):
+                # `+
+                # Store length of each tic group
+                tics.append(len(m.group(3)))
+                # Store start of group, end of group, and escape length
+                tic_points.append((m.start(3), m.end(3) - 1, 0))
+            # Store pipe location
+            elif m.group(5):
+                pipes.append(m.start(5))
+
+        # Pair up tics according to size if possible
+        # Subtract the escape length *only* from the opening.
+        # Walk through tic list and see if tic has a close.
+        # Store the tic region (start of region, end of region).
+        pos = 0
+        tic_len = len(tics)
+        while pos < tic_len:
+            try:
+                tic_size = tics[pos] - tic_points[pos][2]
+                if tic_size == 0:
+                    raise ValueError
+                index = tics[pos + 1:].index(tic_size) + 1
+                tic_region.append((tic_points[pos][0], tic_points[pos + index][1]))
+                pos += index + 1
+            except ValueError:
+                pos += 1
+
+        # Resolve pipes.  Check if they are within a tic pair region.
+        # Walk through pipes comparing them to each region.
+        #     - If pipe position is less that a region, it isn't in a region
+        #     - If it is within a region, we don't want it, so throw it out
+        #     - If we didn't throw it out, it must be a table pipe
+        for pipe in pipes:
+            throw_out = False
+            for region in tic_region:
+                if pipe < region[0]:
+                    # Pipe is not in a region
+                    break
+                elif region[0] <= pipe <= region[1]:
+                    # Pipe is within a code region.  Throw it out.
+                    throw_out = True
+                    break
+            if not throw_out:
+                good_pipes.append(pipe)
+
+        # Split row according to table delimiters.
+        pos = 0
+        for pipe in good_pipes:
+            elements.append(row[pos:pipe])
+            pos = pipe + 1
+        elements.append(row[pos:])
+        return elements
+
+
+class TableExtension(Extension):
+    """ Add tables to Markdown. """
+
+    def __init__(self, **kwargs):
+        self.config = {
+            'use_align_attribute': [False, 'True to use align attribute instead of style.'],
+        }
+        """ Default configuration options. """
+
+        super().__init__(**kwargs)
+
+    def extendMarkdown(self, md):
+        """ Add an instance of `TableProcessor` to `BlockParser`. """
+        if '|' not in md.ESCAPED_CHARS:
+            md.ESCAPED_CHARS.append('|')
+        processor = TableProcessor(md.parser, self.getConfigs())
+        md.parser.blockprocessors.register(processor, 'table', 75)
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    return TableExtension(**kwargs)

plugins/markdown_preview/markdown/extensions/toc.py

@@ -0,0 +1,408 @@
+# Table of Contents Extension for Python-Markdown
+# ===============================================
+
+# See https://Python-Markdown.github.io/extensions/toc
+# for documentation.
+
+# Original code Copyright 2008 [Jack Miller](https://codezen.org/)
+
+# All changes Copyright 2008-2014 The Python Markdown Project
+
+# License: [BSD](https://opensource.org/licenses/bsd-license.php)
+
+"""
+Add table of contents support to Python-Markdown.
+
+See the [documentation](https://Python-Markdown.github.io/extensions/toc)
+for details.
+"""
+
+from __future__ import annotations
+
+from . import Extension
+from ..treeprocessors import Treeprocessor
+from ..util import code_escape, parseBoolValue, AMP_SUBSTITUTE, HTML_PLACEHOLDER_RE, AtomicString
+from ..treeprocessors import UnescapeTreeprocessor
+import re
+import html
+import unicodedata
+import xml.etree.ElementTree as etree
+
+
+def slugify(value, separator, unicode=False):
+    """ Slugify a string, to make it URL friendly. """
+    if not unicode:
+        # Replace Extended Latin characters with ASCII, i.e. `žlutý` => `zluty`
+        value = unicodedata.normalize('NFKD', value)
+        value = value.encode('ascii', 'ignore').decode('ascii')
+    value = re.sub(r'[^\w\s-]', '', value).strip().lower()
+    return re.sub(r'[{}\s]+'.format(separator), separator, value)
+
+
+def slugify_unicode(value, separator):
+    """ Slugify a string, to make it URL friendly while preserving Unicode characters. """
+    return slugify(value, separator, unicode=True)
+
+
+IDCOUNT_RE = re.compile(r'^(.*)_([0-9]+)$')
+
+
+def unique(id, ids):
+    """ Ensure id is unique in set of ids. Append '_1', '_2'... if not """
+    while id in ids or not id:
+        m = IDCOUNT_RE.match(id)
+        if m:
+            id = '%s_%d' % (m.group(1), int(m.group(2))+1)
+        else:
+            id = '%s_%d' % (id, 1)
+    ids.add(id)
+    return id
+
+
+def get_name(el):
+    """Get title name."""
+
+    text = []
+    for c in el.itertext():
+        if isinstance(c, AtomicString):
+            text.append(html.unescape(c))
+        else:
+            text.append(c)
+    return ''.join(text).strip()
+
+
+def stashedHTML2text(text, md, strip_entities: bool = True):
+    """ Extract raw HTML from stash, reduce to plain text and swap with placeholder. """
+    def _html_sub(m):
+        """ Substitute raw html with plain text. """
+        try:
+            raw = md.htmlStash.rawHtmlBlocks[int(m.group(1))]
+        except (IndexError, TypeError):  # pragma: no cover
+            return m.group(0)
+        # Strip out tags and/or entities - leaving text
+        res = re.sub(r'(<[^>]+>)', '', raw)
+        if strip_entities:
+            res = re.sub(r'(&[\#a-zA-Z0-9]+;)', '', res)
+        return res
+
+    return HTML_PLACEHOLDER_RE.sub(_html_sub, text)
+
+
+def unescape(text):
+    """ Unescape escaped text. """
+    c = UnescapeTreeprocessor()
+    return c.unescape(text)
+
+
+def nest_toc_tokens(toc_list):
+    """Given an unsorted list with errors and skips, return a nested one.
+
+        [{'level': 1}, {'level': 2}]
+        =>
+        [{'level': 1, 'children': [{'level': 2, 'children': []}]}]
+
+    A wrong list is also converted:
+
+        [{'level': 2}, {'level': 1}]
+        =>
+        [{'level': 2, 'children': []}, {'level': 1, 'children': []}]
+    """
+
+    ordered_list = []
+    if len(toc_list):
+        # Initialize everything by processing the first entry
+        last = toc_list.pop(0)
+        last['children'] = []
+        levels = [last['level']]
+        ordered_list.append(last)
+        parents = []
+
+        # Walk the rest nesting the entries properly
+        while toc_list:
+            t = toc_list.pop(0)
+            current_level = t['level']
+            t['children'] = []
+
+            # Reduce depth if current level < last item's level
+            if current_level < levels[-1]:
+                # Pop last level since we know we are less than it
+                levels.pop()
+
+                # Pop parents and levels we are less than or equal to
+                to_pop = 0
+                for p in reversed(parents):
+                    if current_level <= p['level']:
+                        to_pop += 1
+                    else:  # pragma: no cover
+                        break
+                if to_pop:
+                    levels = levels[:-to_pop]
+                    parents = parents[:-to_pop]
+
+                # Note current level as last
+                levels.append(current_level)
+
+            # Level is the same, so append to
+            # the current parent (if available)
+            if current_level == levels[-1]:
+                (parents[-1]['children'] if parents
+                 else ordered_list).append(t)
+
+            # Current level is > last item's level,
+            # So make last item a parent and append current as child
+            else:
+                last['children'].append(t)
+                parents.append(last)
+                levels.append(current_level)
+            last = t
+
+    return ordered_list
+
+
+class TocTreeprocessor(Treeprocessor):
+    """ Step through document and build TOC. """
+
+    def __init__(self, md, config):
+        super().__init__(md)
+
+        self.marker = config["marker"]
+        self.title = config["title"]
+        self.base_level = int(config["baselevel"]) - 1
+        self.slugify = config["slugify"]
+        self.sep = config["separator"]
+        self.toc_class = config["toc_class"]
+        self.title_class = config["title_class"]
+        self.use_anchors = parseBoolValue(config["anchorlink"])
+        self.anchorlink_class = config["anchorlink_class"]
+        self.use_permalinks = parseBoolValue(config["permalink"], False)
+        if self.use_permalinks is None:
+            self.use_permalinks = config["permalink"]
+        self.permalink_class = config["permalink_class"]
+        self.permalink_title = config["permalink_title"]
+        self.permalink_leading = parseBoolValue(config["permalink_leading"], False)
+        self.header_rgx = re.compile("[Hh][123456]")
+        if isinstance(config["toc_depth"], str) and '-' in config["toc_depth"]:
+            self.toc_top, self.toc_bottom = [int(x) for x in config["toc_depth"].split('-')]
+        else:
+            self.toc_top = 1
+            self.toc_bottom = int(config["toc_depth"])
+
+    def iterparent(self, node):
+        """ Iterator wrapper to get allowed parent and child all at once. """
+
+        # We do not allow the marker inside a header as that
+        # would causes an endless loop of placing a new TOC
+        # inside previously generated TOC.
+        for child in node:
+            if not self.header_rgx.match(child.tag) and child.tag not in ['pre', 'code']:
+                yield node, child
+                yield from self.iterparent(child)
+
+    def replace_marker(self, root, elem) -> None:
+        """ Replace marker with elem. """
+        for (p, c) in self.iterparent(root):
+            text = ''.join(c.itertext()).strip()
+            if not text:
+                continue
+
+            # To keep the output from screwing up the
+            # validation by putting a `<div>` inside of a `<p>`
+            # we actually replace the `<p>` in its entirety.
+
+            # The `<p>` element may contain more than a single text content
+            # (`nl2br` can introduce a `<br>`). In this situation, `c.text` returns
+            # the very first content, ignore children contents or tail content.
+            # `len(c) == 0` is here to ensure there is only text in the `<p>`.
+            if c.text and c.text.strip() == self.marker and len(c) == 0:
+                for i in range(len(p)):
+                    if p[i] == c:
+                        p[i] = elem
+                        break
+
+    def set_level(self, elem) -> None:
+        """ Adjust header level according to base level. """
+        level = int(elem.tag[-1]) + self.base_level
+        if level > 6:
+            level = 6
+        elem.tag = 'h%d' % level
+
+    def add_anchor(self, c, elem_id) -> None:
+        anchor = etree.Element("a")
+        anchor.text = c.text
+        anchor.attrib["href"] = "#" + elem_id
+        anchor.attrib["class"] = self.anchorlink_class
+        c.text = ""
+        for elem in c:
+            anchor.append(elem)
+        while len(c):
+            c.remove(c[0])
+        c.append(anchor)
+
+    def add_permalink(self, c, elem_id) -> None:
+        permalink = etree.Element("a")
+        permalink.text = ("%spara;" % AMP_SUBSTITUTE
+                          if self.use_permalinks is True
+                          else self.use_permalinks)
+        permalink.attrib["href"] = "#" + elem_id
+        permalink.attrib["class"] = self.permalink_class
+        if self.permalink_title:
+            permalink.attrib["title"] = self.permalink_title
+        if self.permalink_leading:
+            permalink.tail = c.text
+            c.text = ""
+            c.insert(0, permalink)
+        else:
+            c.append(permalink)
+
+    def build_toc_div(self, toc_list):
+        """ Return a string div given a toc list. """
+        div = etree.Element("div")
+        div.attrib["class"] = self.toc_class
+
+        # Add title to the div
+        if self.title:
+            header = etree.SubElement(div, "span")
+            if self.title_class:
+                header.attrib["class"] = self.title_class
+            header.text = self.title
+
+        def build_etree_ul(toc_list, parent):
+            ul = etree.SubElement(parent, "ul")
+            for item in toc_list:
+                # List item link, to be inserted into the toc div
+                li = etree.SubElement(ul, "li")
+                link = etree.SubElement(li, "a")
+                link.text = item.get('name', '')
+                link.attrib["href"] = '#' + item.get('id', '')
+                if item['children']:
+                    build_etree_ul(item['children'], li)
+            return ul
+
+        build_etree_ul(toc_list, div)
+
+        if 'prettify' in self.md.treeprocessors:
+            self.md.treeprocessors['prettify'].run(div)
+
+        return div
+
+    def run(self, doc):
+        # Get a list of id attributes
+        used_ids = set()
+        for el in doc.iter():
+            if "id" in el.attrib:
+                used_ids.add(el.attrib["id"])
+
+        toc_tokens = []
+        for el in doc.iter():
+            if isinstance(el.tag, str) and self.header_rgx.match(el.tag):
+                self.set_level(el)
+                text = get_name(el)
+
+                # Do not override pre-existing ids
+                if "id" not in el.attrib:
+                    innertext = unescape(stashedHTML2text(text, self.md))
+                    el.attrib["id"] = unique(self.slugify(innertext, self.sep), used_ids)
+
+                if int(el.tag[-1]) >= self.toc_top and int(el.tag[-1]) <= self.toc_bottom:
+                    toc_tokens.append({
+                        'level': int(el.tag[-1]),
+                        'id': el.attrib["id"],
+                        'name': unescape(stashedHTML2text(
+                            code_escape(el.attrib.get('data-toc-label', text)),
+                            self.md, strip_entities=False
+                        ))
+                    })
+
+                # Remove the data-toc-label attribute as it is no longer needed
+                if 'data-toc-label' in el.attrib:
+                    del el.attrib['data-toc-label']
+
+                if self.use_anchors:
+                    self.add_anchor(el, el.attrib["id"])
+                if self.use_permalinks not in [False, None]:
+                    self.add_permalink(el, el.attrib["id"])
+
+        toc_tokens = nest_toc_tokens(toc_tokens)
+        div = self.build_toc_div(toc_tokens)
+        if self.marker:
+            self.replace_marker(doc, div)
+
+        # serialize and attach to markdown instance.
+        toc = self.md.serializer(div)
+        for pp in self.md.postprocessors:
+            toc = pp.run(toc)
+        self.md.toc_tokens = toc_tokens
+        self.md.toc = toc
+
+
+class TocExtension(Extension):
+
+    TreeProcessorClass = TocTreeprocessor
+
+    def __init__(self, **kwargs):
+        self.config = {
+            'marker': [
+                '[TOC]',
+                'Text to find and replace with Table of Contents. Set to an empty string to disable. '
+                'Default: `[TOC]`.'
+            ],
+            'title': [
+                '', 'Title to insert into TOC `<div>`. Default: an empty string.'
+            ],
+            'title_class': [
+                'toctitle', 'CSS class used for the title. Default: `toctitle`.'
+            ],
+            'toc_class': [
+                'toc', 'CSS class(es) used for the link. Default: `toclink`.'
+            ],
+            'anchorlink': [
+                False, 'True if header should be a self link. Default: `False`.'
+            ],
+            'anchorlink_class': [
+                'toclink', 'CSS class(es) used for the link. Defaults: `toclink`.'
+            ],
+            'permalink': [
+                0, 'True or link text if a Sphinx-style permalink should be added. Default: `False`.'
+            ],
+            'permalink_class': [
+                'headerlink', 'CSS class(es) used for the link. Default: `headerlink`.'
+            ],
+            'permalink_title': [
+                'Permanent link', 'Title attribute of the permalink. Default: `Permanent link`.'
+            ],
+            'permalink_leading': [
+                False,
+                'True if permalinks should be placed at start of the header, rather than end. Default: False.'
+            ],
+            'baselevel': ['1', 'Base level for headers. Default: `1`.'],
+            'slugify': [
+                slugify, 'Function to generate anchors based on header text. Default: `slugify`.'
+            ],
+            'separator': ['-', 'Word separator. Default: `-`.'],
+            'toc_depth': [
+                6,
+                'Define the range of section levels to include in the Table of Contents. A single integer '
+                '(b) defines the bottom section level (<h1>..<hb>) only. A string consisting of two digits '
+                'separated by a hyphen in between (`2-5`) defines the top (t) and the bottom (b) (<ht>..<hb>). '
+                'Default: `6` (bottom).'
+            ],
+        }
+        """ Default configuration options. """
+
+        super().__init__(**kwargs)
+
+    def extendMarkdown(self, md):
+        """ Add TOC tree processor to Markdown. """
+        md.registerExtension(self)
+        self.md = md
+        self.reset()
+        tocext = self.TreeProcessorClass(md, self.getConfigs())
+        md.treeprocessors.register(tocext, 'toc', 5)
+
+    def reset(self) -> None:
+        self.md.toc = ''
+        self.md.toc_tokens = []
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    return TocExtension(**kwargs)

plugins/markdown_preview/markdown/extensions/wikilinks.py

@@ -0,0 +1,96 @@
+# WikiLinks Extension for Python-Markdown
+# ======================================
+
+# Converts [[WikiLinks]] to relative links.
+
+# See https://Python-Markdown.github.io/extensions/wikilinks
+# for documentation.
+
+# Original code Copyright [Waylan Limberg](http://achinghead.com/).
+
+# All changes Copyright The Python Markdown Project
+
+# License: [BSD](https://opensource.org/licenses/bsd-license.php)
+
+"""
+Converts `[[WikiLinks]]` to relative links.
+
+See the [documentation](https://Python-Markdown.github.io/extensions/wikilinks)
+for details.
+"""
+
+from __future__ import annotations
+
+from . import Extension
+from ..inlinepatterns import InlineProcessor
+import xml.etree.ElementTree as etree
+import re
+
+
+def build_url(label, base, end):
+    """ Build a URL from the label, a base, and an end. """
+    clean_label = re.sub(r'([ ]+_)|(_[ ]+)|([ ]+)', '_', label)
+    return '{}{}{}'.format(base, clean_label, end)
+
+
+class WikiLinkExtension(Extension):
+    """ Add inline processor to Markdown. """
+
+    def __init__(self, **kwargs):
+        self.config = {
+            'base_url': ['/', 'String to append to beginning or URL.'],
+            'end_url': ['/', 'String to append to end of URL.'],
+            'html_class': ['wikilink', 'CSS hook. Leave blank for none.'],
+            'build_url': [build_url, 'Callable formats URL from label.'],
+        }
+        """ Default configuration options. """
+        super().__init__(**kwargs)
+
+    def extendMarkdown(self, md):
+        self.md = md
+
+        # append to end of inline patterns
+        WIKILINK_RE = r'\[\[([\w0-9_ -]+)\]\]'
+        wikilinkPattern = WikiLinksInlineProcessor(WIKILINK_RE, self.getConfigs())
+        wikilinkPattern.md = md
+        md.inlinePatterns.register(wikilinkPattern, 'wikilink', 75)
+
+
+class WikiLinksInlineProcessor(InlineProcessor):
+    """ Build link from `wikilink`. """
+
+    def __init__(self, pattern, config):
+        super().__init__(pattern)
+        self.config = config
+
+    def handleMatch(self, m, data):
+        if m.group(1).strip():
+            base_url, end_url, html_class = self._getMeta()
+            label = m.group(1).strip()
+            url = self.config['build_url'](label, base_url, end_url)
+            a = etree.Element('a')
+            a.text = label
+            a.set('href', url)
+            if html_class:
+                a.set('class', html_class)
+        else:
+            a = ''
+        return a, m.start(0), m.end(0)
+
+    def _getMeta(self):
+        """ Return meta data or `config` data. """
+        base_url = self.config['base_url']
+        end_url = self.config['end_url']
+        html_class = self.config['html_class']
+        if hasattr(self.md, 'Meta'):
+            if 'wiki_base_url' in self.md.Meta:
+                base_url = self.md.Meta['wiki_base_url'][0]
+            if 'wiki_end_url' in self.md.Meta:
+                end_url = self.md.Meta['wiki_end_url'][0]
+            if 'wiki_html_class' in self.md.Meta:
+                html_class = self.md.Meta['wiki_html_class'][0]
+        return base_url, end_url, html_class
+
+
+def makeExtension(**kwargs):  # pragma: no cover
+    return WikiLinkExtension(**kwargs)

plugins/markdown_preview/markdown/htmlparser.py

@@ -0,0 +1,334 @@
+# Python Markdown
+
+# A Python implementation of John Gruber's Markdown.
+
+# Documentation: https://python-markdown.github.io/
+# GitHub: https://github.com/Python-Markdown/markdown/
+# PyPI: https://pypi.org/project/Markdown/
+
+# Started by Manfred Stienstra (http://www.dwerg.net/).
+# Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
+# Currently maintained by Waylan Limberg (https://github.com/waylan),
+# Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
+
+# Copyright 2007-2023 The Python Markdown Project (v. 1.7 and later)
+# Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
+# Copyright 2004 Manfred Stienstra (the original version)
+
+# License: BSD (see LICENSE.md for details).
+
+"""
+This module imports a copy of [`html.parser.HTMLParser`][] and modifies it heavily through monkey-patches.
+A copy is imported rather than the module being directly imported as this ensures that the user can import
+and  use the unmodified library for their own needs.
+"""
+
+from __future__ import annotations
+
+import re
+import importlib.util
+import sys
+
+
+# Import a copy of the html.parser lib as `htmlparser` so we can monkeypatch it.
+# Users can still do `from html import parser` and get the default behavior.
+spec = importlib.util.find_spec('html.parser')
+htmlparser = importlib.util.module_from_spec(spec)
+spec.loader.exec_module(htmlparser)
+sys.modules['htmlparser'] = htmlparser
+
+# Monkeypatch `HTMLParser` to only accept `?>` to close Processing Instructions.
+htmlparser.piclose = re.compile(r'\?>')
+# Monkeypatch `HTMLParser` to only recognize entity references with a closing semicolon.
+htmlparser.entityref = re.compile(r'&([a-zA-Z][-.a-zA-Z0-9]*);')
+# Monkeypatch `HTMLParser` to no longer support partial entities. We are always feeding a complete block,
+# so the 'incomplete' functionality is unnecessary. As the `entityref` regex is run right before incomplete,
+# and the two regex are the same, then incomplete will simply never match and we avoid the logic within.
+htmlparser.incomplete = htmlparser.entityref
+# Monkeypatch `HTMLParser` to not accept a backtick in a tag name, attribute name, or bare value.
+htmlparser.locatestarttagend_tolerant = re.compile(r"""
+  <[a-zA-Z][^`\t\n\r\f />\x00]*       # tag name <= added backtick here
+  (?:[\s/]*                           # optional whitespace before attribute name
+    (?:(?<=['"\s/])[^`\s/>][^\s/=>]*  # attribute name <= added backtick here
+      (?:\s*=+\s*                     # value indicator
+        (?:'[^']*'                    # LITA-enclosed value
+          |"[^"]*"                    # LIT-enclosed value
+          |(?!['"])[^`>\s]*           # bare value <= added backtick here
+         )
+         (?:\s*,)*                    # possibly followed by a comma
+       )?(?:\s|/(?!>))*
+     )*
+   )?
+  \s*                                 # trailing whitespace
+""", re.VERBOSE)
+
+# Match a blank line at the start of a block of text (two newlines).
+# The newlines may be preceded by additional whitespace.
+blank_line_re = re.compile(r'^([ ]*\n){2}')
+
+
+class HTMLExtractor(htmlparser.HTMLParser):
+    """
+    Extract raw HTML from text.
+
+    The raw HTML is stored in the [`htmlStash`][markdown.util.HtmlStash] of the
+    [`Markdown`][markdown.Markdown] instance passed to `md` and the remaining text
+    is stored in `cleandoc` as a list of strings.
+    """
+
+    def __init__(self, md, *args, **kwargs):
+        if 'convert_charrefs' not in kwargs:
+            kwargs['convert_charrefs'] = False
+
+        # Block tags that should contain no content (self closing)
+        self.empty_tags = set(['hr'])
+
+        self.lineno_start_cache = [0]
+
+        # This calls self.reset
+        super().__init__(*args, **kwargs)
+        self.md = md
+
+    def reset(self):
+        """Reset this instance.  Loses all unprocessed data."""
+        self.inraw = False
+        self.intail = False
+        self.stack = []  # When `inraw==True`, stack contains a list of tags
+        self._cache = []
+        self.cleandoc = []
+        self.lineno_start_cache = [0]
+
+        super().reset()
+
+    def close(self):
+        """Handle any buffered data."""
+        super().close()
+        if len(self.rawdata):
+            # Temp fix for https://bugs.python.org/issue41989
+            # TODO: remove this when the bug is fixed in all supported Python versions.
+            if self.convert_charrefs and not self.cdata_elem:  # pragma: no cover
+                self.handle_data(htmlparser.unescape(self.rawdata))
+            else:
+                self.handle_data(self.rawdata)
+        # Handle any unclosed tags.
+        if len(self._cache):
+            self.cleandoc.append(self.md.htmlStash.store(''.join(self._cache)))
+            self._cache = []
+
+    @property
+    def line_offset(self) -> int:
+        """Returns char index in `self.rawdata` for the start of the current line. """
+        for ii in range(len(self.lineno_start_cache)-1, self.lineno-1):
+            last_line_start_pos = self.lineno_start_cache[ii]
+            lf_pos = self.rawdata.find('\n', last_line_start_pos)
+            if lf_pos == -1:
+                # No more newlines found. Use end of raw data as start of line beyond end.
+                lf_pos = len(self.rawdata)
+            self.lineno_start_cache.append(lf_pos+1)
+
+        return self.lineno_start_cache[self.lineno-1]
+
+    def at_line_start(self) -> bool:
+        """
+        Returns True if current position is at start of line.
+
+        Allows for up to three blank spaces at start of line.
+        """
+        if self.offset == 0:
+            return True
+        if self.offset > 3:
+            return False
+        # Confirm up to first 3 chars are whitespace
+        return self.rawdata[self.line_offset:self.line_offset + self.offset].strip() == ''
+
+    def get_endtag_text(self, tag: str) -> str:
+        """
+        Returns the text of the end tag.
+
+        If it fails to extract the actual text from the raw data, it builds a closing tag with `tag`.
+        """
+        # Attempt to extract actual tag from raw source text
+        start = self.line_offset + self.offset
+        m = htmlparser.endendtag.search(self.rawdata, start)
+        if m:
+            return self.rawdata[start:m.end()]
+        else:  # pragma: no cover
+            # Failed to extract from raw data. Assume well formed and lowercase.
+            return '</{}>'.format(tag)
+
+    def handle_starttag(self, tag: str, attrs: list[tuple[str, str]]):
+        # Handle tags that should always be empty and do not specify a closing tag
+        if tag in self.empty_tags:
+            self.handle_startendtag(tag, attrs)
+            return
+
+        if self.md.is_block_level(tag) and (self.intail or (self.at_line_start() and not self.inraw)):
+            # Started a new raw block. Prepare stack.
+            self.inraw = True
+            self.cleandoc.append('\n')
+
+        text = self.get_starttag_text()
+        if self.inraw:
+            self.stack.append(tag)
+            self._cache.append(text)
+        else:
+            self.cleandoc.append(text)
+            if tag in self.CDATA_CONTENT_ELEMENTS:
+                # This is presumably a standalone tag in a code span (see #1036).
+                self.clear_cdata_mode()
+
+    def handle_endtag(self, tag: str):
+        text = self.get_endtag_text(tag)
+
+        if self.inraw:
+            self._cache.append(text)
+            if tag in self.stack:
+                # Remove tag from stack
+                while self.stack:
+                    if self.stack.pop() == tag:
+                        break
+            if len(self.stack) == 0:
+                # End of raw block.
+                if blank_line_re.match(self.rawdata[self.line_offset + self.offset + len(text):]):
+                    # Preserve blank line and end of raw block.
+                    self._cache.append('\n')
+                else:
+                    # More content exists after `endtag`.
+                    self.intail = True
+                # Reset stack.
+                self.inraw = False
+                self.cleandoc.append(self.md.htmlStash.store(''.join(self._cache)))
+                # Insert blank line between this and next line.
+                self.cleandoc.append('\n\n')
+                self._cache = []
+        else:
+            self.cleandoc.append(text)
+
+    def handle_data(self, data: str):
+        if self.intail and '\n' in data:
+            self.intail = False
+        if self.inraw:
+            self._cache.append(data)
+        else:
+            self.cleandoc.append(data)
+
+    def handle_empty_tag(self, data: str, is_block: bool):
+        """ Handle empty tags (`<data>`). """
+        if self.inraw or self.intail:
+            # Append this to the existing raw block
+            self._cache.append(data)
+        elif self.at_line_start() and is_block:
+            # Handle this as a standalone raw block
+            if blank_line_re.match(self.rawdata[self.line_offset + self.offset + len(data):]):
+                # Preserve blank line after tag in raw block.
+                data += '\n'
+            else:
+                # More content exists after tag.
+                self.intail = True
+            item = self.cleandoc[-1] if self.cleandoc else ''
+            # If we only have one newline before block element, add another
+            if not item.endswith('\n\n') and item.endswith('\n'):
+                self.cleandoc.append('\n')
+            self.cleandoc.append(self.md.htmlStash.store(data))
+            # Insert blank line between this and next line.
+            self.cleandoc.append('\n\n')
+        else:
+            self.cleandoc.append(data)
+
+    def handle_startendtag(self, tag: str, attrs: list[tuple[str, str]]):
+        self.handle_empty_tag(self.get_starttag_text(), is_block=self.md.is_block_level(tag))
+
+    def handle_charref(self, name: str):
+        self.handle_empty_tag('&#{};'.format(name), is_block=False)
+
+    def handle_entityref(self, name: str):
+        self.handle_empty_tag('&{};'.format(name), is_block=False)
+
+    def handle_comment(self, data: str):
+        self.handle_empty_tag('<!--{}-->'.format(data), is_block=True)
+
+    def handle_decl(self, data: str):
+        self.handle_empty_tag('<!{}>'.format(data), is_block=True)
+
+    def handle_pi(self, data: str):
+        self.handle_empty_tag('<?{}?>'.format(data), is_block=True)
+
+    def unknown_decl(self, data: str):
+        end = ']]>' if data.startswith('CDATA[') else ']>'
+        self.handle_empty_tag('<![{}{}'.format(data, end), is_block=True)
+
+    def parse_pi(self, i: int) -> int:
+        if self.at_line_start() or self.intail:
+            return super().parse_pi(i)
+        # This is not the beginning of a raw block so treat as plain data
+        # and avoid consuming any tags which may follow (see #1066).
+        self.handle_data('<?')
+        return i + 2
+
+    def parse_html_declaration(self, i: int) -> int:
+        if self.at_line_start() or self.intail:
+            return super().parse_html_declaration(i)
+        # This is not the beginning of a raw block so treat as plain data
+        # and avoid consuming any tags which may follow (see #1066).
+        self.handle_data('<!')
+        return i + 2
+
+    # The rest has been copied from base class in standard lib to address #1036.
+    # As `__startag_text` is private, all references to it must be in this subclass.
+    # The last few lines of `parse_starttag` are reversed so that `handle_starttag`
+    # can override `cdata_mode` in certain situations (in a code span).
+    __starttag_text: str | None = None
+
+    def get_starttag_text(self) -> str:
+        """Return full source of start tag: `<...>`."""
+        return self.__starttag_text
+
+    def parse_starttag(self, i: int) -> int:  # pragma: no cover
+        self.__starttag_text = None
+        endpos = self.check_for_whole_start_tag(i)
+        if endpos < 0:
+            return endpos
+        rawdata = self.rawdata
+        self.__starttag_text = rawdata[i:endpos]
+
+        # Now parse the data between `i+1` and `j` into a tag and `attrs`
+        attrs = []
+        match = htmlparser.tagfind_tolerant.match(rawdata, i+1)
+        assert match, 'unexpected call to parse_starttag()'
+        k = match.end()
+        self.lasttag = tag = match.group(1).lower()
+        while k < endpos:
+            m = htmlparser.attrfind_tolerant.match(rawdata, k)
+            if not m:
+                break
+            attrname, rest, attrvalue = m.group(1, 2, 3)
+            if not rest:
+                attrvalue = None
+            elif attrvalue[:1] == '\'' == attrvalue[-1:] or \
+                 attrvalue[:1] == '"' == attrvalue[-1:]:  # noqa: E127
+                attrvalue = attrvalue[1:-1]
+            if attrvalue:
+                attrvalue = htmlparser.unescape(attrvalue)
+            attrs.append((attrname.lower(), attrvalue))
+            k = m.end()
+
+        end = rawdata[k:endpos].strip()
+        if end not in (">", "/>"):
+            lineno, offset = self.getpos()
+            if "\n" in self.__starttag_text:
+                lineno = lineno + self.__starttag_text.count("\n")
+                offset = len(self.__starttag_text) \
+                         - self.__starttag_text.rfind("\n")  # noqa: E127
+            else:
+                offset = offset + len(self.__starttag_text)
+            self.handle_data(rawdata[i:endpos])
+            return endpos
+        if end.endswith('/>'):
+            # XHTML-style empty tag: `<span attr="value" />`
+            self.handle_startendtag(tag, attrs)
+        else:
+            # *** set `cdata_mode` first so we can override it in `handle_starttag` (see #1036) ***
+            if tag in self.CDATA_CONTENT_ELEMENTS:
+                self.set_cdata_mode(tag)
+            self.handle_starttag(tag, attrs)
+        return endpos

plugins/markdown_preview/markdown/inlinepatterns.py

@@ -0,0 +1,992 @@
+# Python Markdown
+
+# A Python implementation of John Gruber's Markdown.
+
+# Documentation: https://python-markdown.github.io/
+# GitHub: https://github.com/Python-Markdown/markdown/
+# PyPI: https://pypi.org/project/Markdown/
+
+# Started by Manfred Stienstra (http://www.dwerg.net/).
+# Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
+# Currently maintained by Waylan Limberg (https://github.com/waylan),
+# Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
+
+# Copyright 2007-2023 The Python Markdown Project (v. 1.7 and later)
+# Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
+# Copyright 2004 Manfred Stienstra (the original version)
+
+# License: BSD (see LICENSE.md for details).
+
+"""
+In version 3.0, a new, more flexible inline processor was added, [`markdown.inlinepatterns.InlineProcessor`][].   The
+original inline patterns, which inherit from [`markdown.inlinepatterns.Pattern`][] or one of its children are still
+supported, though users are encouraged to migrate.
+
+The new `InlineProcessor` provides two major enhancements to `Patterns`:
+
+1. Inline Processors no longer need to match the entire block, so regular expressions no longer need to start with
+  `r'^(.*?)'` and end with `r'(.*?)%'`. This runs faster. The returned [`Match`][re.Match] object will only contain
+   what is explicitly matched in the pattern, and extension pattern groups now start with `m.group(1)`.
+
+2.  The `handleMatch` method now takes an additional input called `data`, which is the entire block under analysis,
+    not just what is matched with the specified pattern. The method now returns the element *and* the indexes relative
+    to `data` that the return element is replacing (usually `m.start(0)` and `m.end(0)`).  If the boundaries are
+    returned as `None`, it is assumed that the match did not take place, and nothing will be altered in `data`.
+
+    This allows handling of more complex constructs than regular expressions can handle, e.g., matching nested
+    brackets, and explicit control of the span "consumed" by the processor.
+
+"""
+
+from __future__ import annotations
+
+from . import util
+from typing import TYPE_CHECKING, Any, Collection, NamedTuple
+import re
+import xml.etree.ElementTree as etree
+try:  # pragma: no cover
+    from html import entities
+except ImportError:  # pragma: no cover
+    import htmlentitydefs as entities
+
+if TYPE_CHECKING:  # pragma: no cover
+    from markdown import Markdown
+
+
+def build_inlinepatterns(md: Markdown, **kwargs: Any) -> util.Registry[InlineProcessor]:
+    """
+    Build the default set of inline patterns for Markdown.
+
+    The order in which processors and/or patterns are applied is very important - e.g. if we first replace
+    `http://.../` links with `<a>` tags and _then_ try to replace inline HTML, we would end up with a mess. So, we
+    apply the expressions in the following order:
+
+    * backticks and escaped characters have to be handled before everything else so that we can preempt any markdown
+      patterns by escaping them;
+
+    * then we handle the various types of links (auto-links must be handled before inline HTML);
+
+    * then we handle inline HTML.  At this point we will simply replace all inline HTML strings with a placeholder
+      and add the actual HTML to a stash;
+
+    * finally we apply strong, emphasis, etc.
+
+    """
+    inlinePatterns = util.Registry()
+    inlinePatterns.register(BacktickInlineProcessor(BACKTICK_RE), 'backtick', 190)
+    inlinePatterns.register(EscapeInlineProcessor(ESCAPE_RE, md), 'escape', 180)
+    inlinePatterns.register(ReferenceInlineProcessor(REFERENCE_RE, md), 'reference', 170)
+    inlinePatterns.register(LinkInlineProcessor(LINK_RE, md), 'link', 160)
+    inlinePatterns.register(ImageInlineProcessor(IMAGE_LINK_RE, md), 'image_link', 150)
+    inlinePatterns.register(
+        ImageReferenceInlineProcessor(IMAGE_REFERENCE_RE, md), 'image_reference', 140
+    )
+    inlinePatterns.register(
+        ShortReferenceInlineProcessor(REFERENCE_RE, md), 'short_reference', 130
+    )
+    inlinePatterns.register(
+        ShortImageReferenceInlineProcessor(IMAGE_REFERENCE_RE, md), 'short_image_ref', 125
+    )
+    inlinePatterns.register(AutolinkInlineProcessor(AUTOLINK_RE, md), 'autolink', 120)
+    inlinePatterns.register(AutomailInlineProcessor(AUTOMAIL_RE, md), 'automail', 110)
+    inlinePatterns.register(SubstituteTagInlineProcessor(LINE_BREAK_RE, 'br'), 'linebreak', 100)
+    inlinePatterns.register(HtmlInlineProcessor(HTML_RE, md), 'html', 90)
+    inlinePatterns.register(HtmlInlineProcessor(ENTITY_RE, md), 'entity', 80)
+    inlinePatterns.register(SimpleTextInlineProcessor(NOT_STRONG_RE), 'not_strong', 70)
+    inlinePatterns.register(AsteriskProcessor(r'\*'), 'em_strong', 60)
+    inlinePatterns.register(UnderscoreProcessor(r'_'), 'em_strong2', 50)
+    return inlinePatterns
+
+
+# The actual regular expressions for patterns
+# -----------------------------------------------------------------------------
+
+NOIMG = r'(?<!\!)'
+""" Match not an image. Partial regular expression which matches if not preceded by `!`. """
+
+BACKTICK_RE = r'(?:(?<!\\)((?:\\{2})+)(?=`+)|(?<!\\)(`+)(.+?)(?<!`)\2(?!`))'
+""" Match backtick quoted string (`` `e=f()` `` or ``` ``e=f("`")`` ```). """
+
+ESCAPE_RE = r'\\(.)'
+""" Match a backslash escaped character (`\\<` or `\\*`). """
+
+EMPHASIS_RE = r'(\*)([^\*]+)\1'
+""" Match emphasis with an asterisk (`*emphasis*`). """
+
+STRONG_RE = r'(\*{2})(.+?)\1'
+""" Match strong with an asterisk (`**strong**`). """
+
+SMART_STRONG_RE = r'(?<!\w)(_{2})(?!_)(.+?)(?<!_)\1(?!\w)'
+""" Match strong with underscore while ignoring middle word underscores (`__smart__strong__`). """
+
+SMART_EMPHASIS_RE = r'(?<!\w)(_)(?!_)(.+?)(?<!_)\1(?!\w)'
+""" Match emphasis with underscore while ignoring middle word underscores (`_smart_emphasis_`). """
+
+SMART_STRONG_EM_RE = r'(?<!\w)(\_)\1(?!\1)(.+?)(?<!\w)\1(?!\1)(.+?)\1{3}(?!\w)'
+""" Match strong emphasis with underscores (`__strong _em__`). """
+
+EM_STRONG_RE = r'(\*)\1{2}(.+?)\1(.*?)\1{2}'
+""" Match emphasis strong with asterisk (`***strongem***` or `***em*strong**`). """
+
+EM_STRONG2_RE = r'(_)\1{2}(.+?)\1(.*?)\1{2}'
+""" Match emphasis strong with underscores (`___emstrong___` or `___em_strong__`). """
+
+STRONG_EM_RE = r'(\*)\1{2}(.+?)\1{2}(.*?)\1'
+""" Match strong emphasis with asterisk (`***strong**em*`). """
+
+STRONG_EM2_RE = r'(_)\1{2}(.+?)\1{2}(.*?)\1'
+""" Match strong emphasis with underscores (`___strong__em_`). """
+
+STRONG_EM3_RE = r'(\*)\1(?!\1)([^*]+?)\1(?!\1)(.+?)\1{3}'
+""" Match strong emphasis with asterisk (`**strong*em***`). """
+
+LINK_RE = NOIMG + r'\['
+""" Match start of in-line link (`[text](url)` or `[text](<url>)` or `[text](url "title")`). """
+
+IMAGE_LINK_RE = r'\!\['
+""" Match start of in-line image link (`![alttxt](url)` or `![alttxt](<url>)`). """
+
+REFERENCE_RE = LINK_RE
+""" Match start of reference link (`[Label][3]`). """
+
+IMAGE_REFERENCE_RE = IMAGE_LINK_RE
+""" Match start of image reference (`![alt text][2]`). """
+
+NOT_STRONG_RE = r'((^|(?<=\s))(\*{1,3}|_{1,3})(?=\s|$))'
+""" Match a stand-alone `*` or `_`. """
+
+AUTOLINK_RE = r'<((?:[Ff]|[Hh][Tt])[Tt][Pp][Ss]?://[^<>]*)>'
+""" Match an automatic link (`<http://www.example.com>`). """
+
+AUTOMAIL_RE = r'<([^<> !]+@[^@<> ]+)>'
+""" Match an automatic email link (`<me@example.com>`). """
+
+HTML_RE = r'(<(\/?[a-zA-Z][^<>@ ]*( [^<>]*)?|!--(?:(?!<!--|-->).)*--)>)'
+""" Match an HTML tag (`<...>`). """
+
+ENTITY_RE = r'(&(?:\#[0-9]+|\#x[0-9a-fA-F]+|[a-zA-Z0-9]+);)'
+""" Match an HTML entity (`&#38;` (decimal) or `&#x26;` (hex) or `&amp;` (named)). """
+
+LINE_BREAK_RE = r'  \n'
+""" Match two spaces at end of line. """
+
+
+def dequote(string: str) -> str:
+    """Remove quotes from around a string."""
+    if ((string.startswith('"') and string.endswith('"')) or
+       (string.startswith("'") and string.endswith("'"))):
+        return string[1:-1]
+    else:
+        return string
+
+
+class EmStrongItem(NamedTuple):
+    """Emphasis/strong pattern item."""
+    pattern: re.Pattern[str]
+    builder: str
+    tags: str
+
+
+# The pattern classes
+# -----------------------------------------------------------------------------
+
+
+class Pattern:  # pragma: no cover
+    """
+    Base class that inline patterns subclass.
+
+    Inline patterns are handled by means of `Pattern` subclasses, one per regular expression.
+    Each pattern object uses a single regular expression and must support the following methods:
+    [`getCompiledRegExp`][markdown.inlinepatterns.Pattern.getCompiledRegExp] and
+    [`handleMatch`][markdown.inlinepatterns.Pattern.handleMatch].
+
+    All the regular expressions used by `Pattern` subclasses must capture the whole block.  For this
+    reason, they all start with `^(.*)` and end with `(.*)!`.  When passing a regular expression on
+    class initialization, the `^(.*)` and `(.*)!` are added automatically and the regular expression
+    is pre-compiled.
+
+    It is strongly suggested that the newer style [`markdown.inlinepatterns.InlineProcessor`][] that
+    use a more efficient and flexible search approach be used instead. However, the older style
+    `Pattern` remains for backward compatibility with many existing third-party extensions.
+
+    """
+
+    ANCESTOR_EXCLUDES: Collection[str] = tuple()
+    """
+    A collection of elements which are undesirable ancestors. The processor will be skipped if it
+    would cause the content to be a descendant of one of the listed tag names.
+    """
+
+    def __init__(self, pattern: str, md: Markdown | None = None):
+        """
+        Create an instant of an inline pattern.
+
+        Arguments:
+            pattern: A regular expression that matches a pattern.
+            md: An optional pointer to the instance of `markdown.Markdown` and is available as
+                `self.md` on the class instance.
+
+
+        """
+        self.pattern = pattern
+        self.compiled_re = re.compile(r"^(.*?)%s(.*)$" % pattern,
+                                      re.DOTALL | re.UNICODE)
+
+        self.md = md
+
+    def getCompiledRegExp(self) -> re.Pattern:
+        """ Return a compiled regular expression. """
+        return self.compiled_re
+
+    def handleMatch(self, m: re.Match[str]) -> etree.Element | str:
+        """Return a ElementTree element from the given match.
+
+        Subclasses should override this method.
+
+        Arguments:
+            m: A match object containing a match of the pattern.
+
+        Returns: An ElementTree Element object.
+
+        """
+        pass  # pragma: no cover
+
+    def type(self) -> str:
+        """ Return class name, to define pattern type """
+        return self.__class__.__name__
+
+    def unescape(self, text: str) -> str:
+        """ Return unescaped text given text with an inline placeholder. """
+        try:
+            stash = self.md.treeprocessors['inline'].stashed_nodes
+        except KeyError:  # pragma: no cover
+            return text
+
+        def get_stash(m):
+            id = m.group(1)
+            if id in stash:
+                value = stash.get(id)
+                if isinstance(value, str):
+                    return value
+                else:
+                    # An `etree` Element - return text content only
+                    return ''.join(value.itertext())
+        return util.INLINE_PLACEHOLDER_RE.sub(get_stash, text)
+
+
+class InlineProcessor(Pattern):
+    """
+    Base class that inline processors subclass.
+
+    This is the newer style inline processor that uses a more
+    efficient and flexible search approach.
+
+    """
+
+    def __init__(self, pattern: str, md: Markdown | None = None):
+        """
+        Create an instant of an inline processor.
+
+        Arguments:
+            pattern: A regular expression that matches a pattern.
+            md: An optional pointer to the instance of `markdown.Markdown` and is available as
+                `self.md` on the class instance.
+
+        """
+        self.pattern = pattern
+        self.compiled_re = re.compile(pattern, re.DOTALL | re.UNICODE)
+
+        # API for Markdown to pass `safe_mode` into instance
+        self.safe_mode = False
+        self.md = md
+
+    def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element | str | None, int | None, int | None]:
+        """Return a ElementTree element from the given match and the
+        start and end index of the matched text.
+
+        If `start` and/or `end` are returned as `None`, it will be
+        assumed that the processor did not find a valid region of text.
+
+        Subclasses should override this method.
+
+        Arguments:
+            m: A re match object containing a match of the pattern.
+            data: The buffer currently under analysis.
+
+        Returns:
+            el: The ElementTree element, text or None.
+            start: The start of the region that has been matched or None.
+            end: The end of the region that has been matched or None.
+
+        """
+        pass  # pragma: no cover
+
+
+class SimpleTextPattern(Pattern):  # pragma: no cover
+    """ Return a simple text of `group(2)` of a Pattern. """
+    def handleMatch(self, m: re.Match[str]) -> str:
+        """ Return string content of `group(2)` of a matching pattern. """
+        return m.group(2)
+
+
+class SimpleTextInlineProcessor(InlineProcessor):
+    """ Return a simple text of `group(1)` of a Pattern. """
+    def handleMatch(self, m: re.Match[str], data: str) -> tuple[str, int, int]:
+        """ Return string content of `group(1)` of a matching pattern. """
+        return m.group(1), m.start(0), m.end(0)
+
+
+class EscapeInlineProcessor(InlineProcessor):
+    """ Return an escaped character. """
+
+    def handleMatch(self, m: re.Match[str], data: str) -> tuple[str | None, int, int]:
+        """
+        If the character matched by `group(1)` of a pattern is in [`ESCAPED_CHARS`][markdown.Markdown.ESCAPED_CHARS]
+        then return the integer representing the character's Unicode code point (as returned by [`ord`][]) wrapped
+        in [`util.STX`][markdown.util.STX] and [`util.ETX`][markdown.util.ETX].
+
+        If the matched character is not in [`ESCAPED_CHARS`][markdown.Markdown.ESCAPED_CHARS], then return `None`.
+        """
+
+        char = m.group(1)
+        if char in self.md.ESCAPED_CHARS:
+            return '{}{}{}'.format(util.STX, ord(char), util.ETX), m.start(0), m.end(0)
+        else:
+            return None, m.start(0), m.end(0)
+
+
+class SimpleTagPattern(Pattern):  # pragma: no cover
+    """
+    Return element of type `tag` with a text attribute of `group(3)`
+    of a Pattern.
+
+    """
+    def __init__(self, pattern: str, tag: str):
+        """
+        Create an instant of an simple tag pattern.
+
+        Arguments:
+            pattern: A regular expression that matches a pattern.
+            tag: Tag of element.
+
+        """
+        Pattern.__init__(self, pattern)
+        self.tag = tag
+        """ The tag of the rendered element. """
+
+    def handleMatch(self, m: re.Match[str]) -> etree.Element:
+        """
+        Return [`Element`][xml.etree.ElementTree.Element] of type `tag` with the string in `group(3)` of a
+        matching pattern as the Element's text.
+        """
+        el = etree.Element(self.tag)
+        el.text = m.group(3)
+        return el
+
+
+class SimpleTagInlineProcessor(InlineProcessor):
+    """
+    Return element of type `tag` with a text attribute of `group(2)`
+    of a Pattern.
+
+    """
+    def __init__(self, pattern: str, tag: str):
+        """
+        Create an instant of an simple tag processor.
+
+        Arguments:
+            pattern: A regular expression that matches a pattern.
+            tag: Tag of element.
+
+        """
+        InlineProcessor.__init__(self, pattern)
+        self.tag = tag
+        """ The tag of the rendered element. """
+
+    def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element, int, int]:  # pragma: no cover
+        """
+        Return [`Element`][xml.etree.ElementTree.Element] of type `tag` with the string in `group(2)` of a
+        matching pattern as the Element's text.
+        """
+        el = etree.Element(self.tag)
+        el.text = m.group(2)
+        return el, m.start(0), m.end(0)
+
+
+class SubstituteTagPattern(SimpleTagPattern):  # pragma: no cover
+    """ Return an element of type `tag` with no children. """
+    def handleMatch(self, m: re.Match[str]) -> etree.Element:
+        """ Return empty [`Element`][xml.etree.ElementTree.Element] of type `tag`. """
+        return etree.Element(self.tag)
+
+
+class SubstituteTagInlineProcessor(SimpleTagInlineProcessor):
+    """ Return an element of type `tag` with no children. """
+    def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element, int, int]:
+        """ Return empty [`Element`][xml.etree.ElementTree.Element] of type `tag`. """
+        return etree.Element(self.tag), m.start(0), m.end(0)
+
+
+class BacktickInlineProcessor(InlineProcessor):
+    """ Return a `<code>` element containing the escaped matching text. """
+    def __init__(self, pattern):
+        InlineProcessor.__init__(self, pattern)
+        self.ESCAPED_BSLASH = '{}{}{}'.format(util.STX, ord('\\'), util.ETX)
+        self.tag = 'code'
+        """ The tag of the rendered element. """
+
+    def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element | str, int, int]:
+        """
+        If the match contains `group(3)` of a pattern, then return a `code`
+        [`Element`][xml.etree.ElementTree.Element] which contains HTML escaped text (with
+        [`code_escape`][markdown.util.code_escape]) as an [`AtomicString`][markdown.util.AtomicString].
+
+        If the match does not contain `group(3)` then return the text of `group(1)` backslash escaped.
+
+        """
+        if m.group(3):
+            el = etree.Element(self.tag)
+            el.text = util.AtomicString(util.code_escape(m.group(3).strip()))
+            return el, m.start(0), m.end(0)
+        else:
+            return m.group(1).replace('\\\\', self.ESCAPED_BSLASH), m.start(0), m.end(0)
+
+
+class DoubleTagPattern(SimpleTagPattern):  # pragma: no cover
+    """Return a ElementTree element nested in tag2 nested in tag1.
+
+    Useful for strong emphasis etc.
+
+    """
+    def handleMatch(self, m: re.Match[str]) -> etree.Element:
+        """
+        Return [`Element`][xml.etree.ElementTree.Element] in following format:
+        `<tag1><tag2>group(3)</tag2>group(4)</tag2>` where `group(4)` is optional.
+
+        """
+        tag1, tag2 = self.tag.split(",")
+        el1 = etree.Element(tag1)
+        el2 = etree.SubElement(el1, tag2)
+        el2.text = m.group(3)
+        if len(m.groups()) == 5:
+            el2.tail = m.group(4)
+        return el1
+
+
+class DoubleTagInlineProcessor(SimpleTagInlineProcessor):
+    """Return a ElementTree element nested in tag2 nested in tag1.
+
+    Useful for strong emphasis etc.
+
+    """
+    def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element, int, int]:  # pragma: no cover
+        """
+        Return [`Element`][xml.etree.ElementTree.Element] in following format:
+        `<tag1><tag2>group(2)</tag2>group(3)</tag2>` where `group(3)` is optional.
+
+        """
+        tag1, tag2 = self.tag.split(",")
+        el1 = etree.Element(tag1)
+        el2 = etree.SubElement(el1, tag2)
+        el2.text = m.group(2)
+        if len(m.groups()) == 3:
+            el2.tail = m.group(3)
+        return el1, m.start(0), m.end(0)
+
+
+class HtmlInlineProcessor(InlineProcessor):
+    """ Store raw inline html and return a placeholder. """
+    def handleMatch(self, m: re.Match[str], data: str) -> tuple[str, int, int]:
+        """ Store the text of `group(1)` of a pattern and return a placeholder string. """
+        rawhtml = self.backslash_unescape(self.unescape(m.group(1)))
+        place_holder = self.md.htmlStash.store(rawhtml)
+        return place_holder, m.start(0), m.end(0)
+
+    def unescape(self, text):
+        """ Return unescaped text given text with an inline placeholder. """
+        try:
+            stash = self.md.treeprocessors['inline'].stashed_nodes
+        except KeyError:  # pragma: no cover
+            return text
+
+        def get_stash(m):
+            id = m.group(1)
+            value = stash.get(id)
+            if value is not None:
+                try:
+                    return self.md.serializer(value)
+                except Exception:
+                    return r'\%s' % value
+
+        return util.INLINE_PLACEHOLDER_RE.sub(get_stash, text)
+
+    def backslash_unescape(self, text):
+        """ Return text with backslash escapes undone (backslashes are restored). """
+        try:
+            RE = self.md.treeprocessors['unescape'].RE
+        except KeyError:  # pragma: no cover
+            return text
+
+        def _unescape(m):
+            return chr(int(m.group(1)))
+
+        return RE.sub(_unescape, text)
+
+
+class AsteriskProcessor(InlineProcessor):
+    """Emphasis processor for handling strong and em matches inside asterisks."""
+
+    PATTERNS = [
+        EmStrongItem(re.compile(EM_STRONG_RE, re.DOTALL | re.UNICODE), 'double', 'strong,em'),
+        EmStrongItem(re.compile(STRONG_EM_RE, re.DOTALL | re.UNICODE), 'double', 'em,strong'),
+        EmStrongItem(re.compile(STRONG_EM3_RE, re.DOTALL | re.UNICODE), 'double2', 'strong,em'),
+        EmStrongItem(re.compile(STRONG_RE, re.DOTALL | re.UNICODE), 'single', 'strong'),
+        EmStrongItem(re.compile(EMPHASIS_RE, re.DOTALL | re.UNICODE), 'single', 'em')
+    ]
+    """ The various strong and emphasis patterns handled by this processor. """
+
+    def build_single(self, m, tag, idx):
+        """Return single tag."""
+        el1 = etree.Element(tag)
+        text = m.group(2)
+        self.parse_sub_patterns(text, el1, None, idx)
+        return el1
+
+    def build_double(self, m, tags, idx):
+        """Return double tag."""
+
+        tag1, tag2 = tags.split(",")
+        el1 = etree.Element(tag1)
+        el2 = etree.Element(tag2)
+        text = m.group(2)
+        self.parse_sub_patterns(text, el2, None, idx)
+        el1.append(el2)
+        if len(m.groups()) == 3:
+            text = m.group(3)
+            self.parse_sub_patterns(text, el1, el2, idx)
+        return el1
+
+    def build_double2(self, m, tags, idx):
+        """Return double tags (variant 2): `<strong>text <em>text</em></strong>`."""
+
+        tag1, tag2 = tags.split(",")
+        el1 = etree.Element(tag1)
+        el2 = etree.Element(tag2)
+        text = m.group(2)
+        self.parse_sub_patterns(text, el1, None, idx)
+        text = m.group(3)
+        el1.append(el2)
+        self.parse_sub_patterns(text, el2, None, idx)
+        return el1
+
+    def parse_sub_patterns(self, data, parent, last, idx) -> None:
+        """
+        Parses sub patterns.
+
+        `data` (`str`):
+            text to evaluate.
+
+        `parent` (`etree.Element`):
+            Parent to attach text and sub elements to.
+
+        `last` (`etree.Element`):
+            Last appended child to parent. Can also be None if parent has no children.
+
+        `idx` (`int`):
+            Current pattern index that was used to evaluate the parent.
+
+        """
+
+        offset = 0
+        pos = 0
+
+        length = len(data)
+        while pos < length:
+            # Find the start of potential emphasis or strong tokens
+            if self.compiled_re.match(data, pos):
+                matched = False
+                # See if the we can match an emphasis/strong pattern
+                for index, item in enumerate(self.PATTERNS):
+                    # Only evaluate patterns that are after what was used on the parent
+                    if index <= idx:
+                        continue
+                    m = item.pattern.match(data, pos)
+                    if m:
+                        # Append child nodes to parent
+                        # Text nodes should be appended to the last
+                        # child if present, and if not, it should
+                        # be added as the parent's text node.
+                        text = data[offset:m.start(0)]
+                        if text:
+                            if last is not None:
+                                last.tail = text
+                            else:
+                                parent.text = text
+                        el = self.build_element(m, item.builder, item.tags, index)
+                        parent.append(el)
+                        last = el
+                        # Move our position past the matched hunk
+                        offset = pos = m.end(0)
+                        matched = True
+                if not matched:
+                    # We matched nothing, move on to the next character
+                    pos += 1
+            else:
+                # Increment position as no potential emphasis start was found.
+                pos += 1
+
+        # Append any leftover text as a text node.
+        text = data[offset:]
+        if text:
+            if last is not None:
+                last.tail = text
+            else:
+                parent.text = text
+
+    def build_element(self, m, builder, tags, index):
+        """Element builder."""
+
+        if builder == 'double2':
+            return self.build_double2(m, tags, index)
+        elif builder == 'double':
+            return self.build_double(m, tags, index)
+        else:
+            return self.build_single(m, tags, index)
+
+    def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element | None, int | None, int | None]:
+        """Parse patterns."""
+
+        el = None
+        start = None
+        end = None
+
+        for index, item in enumerate(self.PATTERNS):
+            m1 = item.pattern.match(data, m.start(0))
+            if m1:
+                start = m1.start(0)
+                end = m1.end(0)
+                el = self.build_element(m1, item.builder, item.tags, index)
+                break
+        return el, start, end
+
+
+class UnderscoreProcessor(AsteriskProcessor):
+    """Emphasis processor for handling strong and em matches inside underscores."""
+
+    PATTERNS = [
+        EmStrongItem(re.compile(EM_STRONG2_RE, re.DOTALL | re.UNICODE), 'double', 'strong,em'),
+        EmStrongItem(re.compile(STRONG_EM2_RE, re.DOTALL | re.UNICODE), 'double', 'em,strong'),
+        EmStrongItem(re.compile(SMART_STRONG_EM_RE, re.DOTALL | re.UNICODE), 'double2', 'strong,em'),
+        EmStrongItem(re.compile(SMART_STRONG_RE, re.DOTALL | re.UNICODE), 'single', 'strong'),
+        EmStrongItem(re.compile(SMART_EMPHASIS_RE, re.DOTALL | re.UNICODE), 'single', 'em')
+    ]
+    """ The various strong and emphasis patterns handled by this processor. """
+
+
+class LinkInlineProcessor(InlineProcessor):
+    """ Return a link element from the given match. """
+    RE_LINK = re.compile(r'''\(\s*(?:(<[^<>]*>)\s*(?:('[^']*'|"[^"]*")\s*)?\))?''', re.DOTALL | re.UNICODE)
+    RE_TITLE_CLEAN = re.compile(r'\s')
+
+    def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element | None, int | None, int | None]:
+        """ Return an `a` [`Element`][xml.etree.ElementTree.Element] or `(None, None, None)`. """
+        text, index, handled = self.getText(data, m.end(0))
+
+        if not handled:
+            return None, None, None
+
+        href, title, index, handled = self.getLink(data, index)
+        if not handled:
+            return None, None, None
+
+        el = etree.Element("a")
+        el.text = text
+
+        el.set("href", href)
+
+        if title is not None:
+            el.set("title", title)
+
+        return el, m.start(0), index
+
+    def getLink(self, data, index):
+        """Parse data between `()` of `[Text]()` allowing recursive `()`. """
+
+        href = ''
+        title = None
+        handled = False
+
+        m = self.RE_LINK.match(data, pos=index)
+        if m and m.group(1):
+            # Matches [Text](<link> "title")
+            href = m.group(1)[1:-1].strip()
+            if m.group(2):
+                title = m.group(2)[1:-1]
+            index = m.end(0)
+            handled = True
+        elif m:
+            # Track bracket nesting and index in string
+            bracket_count = 1
+            backtrack_count = 1
+            start_index = m.end()
+            index = start_index
+            last_bracket = -1
+
+            # Primary (first found) quote tracking.
+            quote = None
+            start_quote = -1
+            exit_quote = -1
+            ignore_matches = False
+
+            # Secondary (second found) quote tracking.
+            alt_quote = None
+            start_alt_quote = -1
+            exit_alt_quote = -1
+
+            # Track last character
+            last = ''
+
+            for pos in range(index, len(data)):
+                c = data[pos]
+                if c == '(':
+                    # Count nested (
+                    # Don't increment the bracket count if we are sure we're in a title.
+                    if not ignore_matches:
+                        bracket_count += 1
+                    elif backtrack_count > 0:
+                        backtrack_count -= 1
+                elif c == ')':
+                    # Match nested ) to (
+                    # Don't decrement if we are sure we are in a title that is unclosed.
+                    if ((exit_quote != -1 and quote == last) or (exit_alt_quote != -1 and alt_quote == last)):
+                        bracket_count = 0
+                    elif not ignore_matches:
+                        bracket_count -= 1
+                    elif backtrack_count > 0:
+                        backtrack_count -= 1
+                        # We've found our backup end location if the title doesn't resolve.
+                        if backtrack_count == 0:
+                            last_bracket = index + 1
+
+                elif c in ("'", '"'):
+                    # Quote has started
+                    if not quote:
+                        # We'll assume we are now in a title.
+                        # Brackets are quoted, so no need to match them (except for the final one).
+                        ignore_matches = True
+                        backtrack_count = bracket_count
+                        bracket_count = 1
+                        start_quote = index + 1
+                        quote = c
+                    # Secondary quote (in case the first doesn't resolve): [text](link'"title")
+                    elif c != quote and not alt_quote:
+                        start_alt_quote = index + 1
+                        alt_quote = c
+                    # Update primary quote match
+                    elif c == quote:
+                        exit_quote = index + 1
+                    # Update secondary quote match
+                    elif alt_quote and c == alt_quote:
+                        exit_alt_quote = index + 1
+
+                index += 1
+
+                # Link is closed, so let's break out of the loop
+                if bracket_count == 0:
+                    # Get the title if we closed a title string right before link closed
+                    if exit_quote >= 0 and quote == last:
+                        href = data[start_index:start_quote - 1]
+                        title = ''.join(data[start_quote:exit_quote - 1])
+                    elif exit_alt_quote >= 0 and alt_quote == last:
+                        href = data[start_index:start_alt_quote - 1]
+                        title = ''.join(data[start_alt_quote:exit_alt_quote - 1])
+                    else:
+                        href = data[start_index:index - 1]
+                    break
+
+                if c != ' ':
+                    last = c
+
+            # We have a scenario: `[test](link"notitle)`
+            # When we enter a string, we stop tracking bracket resolution in the main counter,
+            # but we do keep a backup counter up until we discover where we might resolve all brackets
+            # if the title string fails to resolve.
+            if bracket_count != 0 and backtrack_count == 0:
+                href = data[start_index:last_bracket - 1]
+                index = last_bracket
+                bracket_count = 0
+
+            handled = bracket_count == 0
+
+        if title is not None:
+            title = self.RE_TITLE_CLEAN.sub(' ', dequote(self.unescape(title.strip())))
+
+        href = self.unescape(href).strip()
+
+        return href, title, index, handled
+
+    def getText(self, data, index):
+        """Parse the content between `[]` of the start of an image or link
+        resolving nested square brackets.
+
+        """
+        bracket_count = 1
+        text = []
+        for pos in range(index, len(data)):
+            c = data[pos]
+            if c == ']':
+                bracket_count -= 1
+            elif c == '[':
+                bracket_count += 1
+            index += 1
+            if bracket_count == 0:
+                break
+            text.append(c)
+        return ''.join(text), index, bracket_count == 0
+
+
+class ImageInlineProcessor(LinkInlineProcessor):
+    """ Return a `img` element from the given match. """
+
+    def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element | None, int | None, int | None]:
+        """ Return an `img` [`Element`][xml.etree.ElementTree.Element] or `(None, None, None)`. """
+        text, index, handled = self.getText(data, m.end(0))
+        if not handled:
+            return None, None, None
+
+        src, title, index, handled = self.getLink(data, index)
+        if not handled:
+            return None, None, None
+
+        el = etree.Element("img")
+
+        el.set("src", src)
+
+        if title is not None:
+            el.set("title", title)
+
+        el.set('alt', self.unescape(text))
+        return el, m.start(0), index
+
+
+class ReferenceInlineProcessor(LinkInlineProcessor):
+    """ Match to a stored reference and return link element. """
+    NEWLINE_CLEANUP_RE = re.compile(r'\s+', re.MULTILINE)
+
+    RE_LINK = re.compile(r'\s?\[([^\]]*)\]', re.DOTALL | re.UNICODE)
+
+    def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element | None, int | None, int | None]:
+        """
+        Return [`Element`][xml.etree.ElementTree.Element] returned by `makeTag` method or `(None, None, None)`.
+
+        """
+        text, index, handled = self.getText(data, m.end(0))
+        if not handled:
+            return None, None, None
+
+        id, end, handled = self.evalId(data, index, text)
+        if not handled:
+            return None, None, None
+
+        # Clean up line breaks in id
+        id = self.NEWLINE_CLEANUP_RE.sub(' ', id)
+        if id not in self.md.references:  # ignore undefined refs
+            return None, m.start(0), end
+
+        href, title = self.md.references[id]
+
+        return self.makeTag(href, title, text), m.start(0), end
+
+    def evalId(self, data, index, text):
+        """
+        Evaluate the id portion of `[ref][id]`.
+
+        If `[ref][]` use `[ref]`.
+        """
+        m = self.RE_LINK.match(data, pos=index)
+        if not m:
+            return None, index, False
+        else:
+            id = m.group(1).lower()
+            end = m.end(0)
+            if not id:
+                id = text.lower()
+        return id, end, True
+
+    def makeTag(self, href: str, title: str, text: str) -> etree.Element:
+        """ Return an `a` [`Element`][xml.etree.ElementTree.Element]. """
+        el = etree.Element('a')
+
+        el.set('href', href)
+        if title:
+            el.set('title', title)
+
+        el.text = text
+        return el
+
+
+class ShortReferenceInlineProcessor(ReferenceInlineProcessor):
+    """Short form of reference: `[google]`. """
+    def evalId(self, data, index, text):
+        """Evaluate the id of `[ref]`.  """
+
+        return text.lower(), index, True
+
+
+class ImageReferenceInlineProcessor(ReferenceInlineProcessor):
+    """ Match to a stored reference and return `img` element. """
+    def makeTag(self, href: str, title: str, text: str) -> etree.Element:
+        """ Return an `img` [`Element`][xml.etree.ElementTree.Element]. """
+        el = etree.Element("img")
+        el.set("src", href)
+        if title:
+            el.set("title", title)
+        el.set("alt", self.unescape(text))
+        return el
+
+
+class ShortImageReferenceInlineProcessor(ImageReferenceInlineProcessor):
+    """ Short form of image reference: `![ref]`. """
+    def evalId(self, data, index, text):
+        """Evaluate the id of `[ref]`.  """
+
+        return text.lower(), index, True
+
+
+class AutolinkInlineProcessor(InlineProcessor):
+    """ Return a link Element given an auto-link (`<http://example/com>`). """
+    def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element, int, int]:
+        """ Return an `a` [`Element`][xml.etree.ElementTree.Element] of `group(1)`. """
+        el = etree.Element("a")
+        el.set('href', self.unescape(m.group(1)))
+        el.text = util.AtomicString(m.group(1))
+        return el, m.start(0), m.end(0)
+
+
+class AutomailInlineProcessor(InlineProcessor):
+    """
+    Return a `mailto` link Element given an auto-mail link (`<foo@example.com>`).
+    """
+    def handleMatch(self, m: re.Match[str], data: str) -> tuple[etree.Element, int, int]:
+        """ Return an [`Element`][xml.etree.ElementTree.Element] containing a `mailto` link  of `group(1)`. """
+        el = etree.Element('a')
+        email = self.unescape(m.group(1))
+        if email.startswith("mailto:"):
+            email = email[len("mailto:"):]
+
+        def codepoint2name(code):
+            """Return entity definition by code, or the code if not defined."""
+            entity = entities.codepoint2name.get(code)
+            if entity:
+                return "{}{};".format(util.AMP_SUBSTITUTE, entity)
+            else:
+                return "%s#%d;" % (util.AMP_SUBSTITUTE, code)
+
+        letters = [codepoint2name(ord(letter)) for letter in email]
+        el.text = util.AtomicString(''.join(letters))
+
+        mailto = "mailto:" + email
+        mailto = "".join([util.AMP_SUBSTITUTE + '#%d;' %
+                          ord(letter) for letter in mailto])
+        el.set('href', mailto)
+        return el, m.start(0), m.end(0)

plugins/markdown_preview/markdown/postprocessors.py

@@ -0,0 +1,143 @@
+# Python Markdown
+
+# A Python implementation of John Gruber's Markdown.
+
+# Documentation: https://python-markdown.github.io/
+# GitHub: https://github.com/Python-Markdown/markdown/
+# PyPI: https://pypi.org/project/Markdown/
+
+# Started by Manfred Stienstra (http://www.dwerg.net/).
+# Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
+# Currently maintained by Waylan Limberg (https://github.com/waylan),
+# Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
+
+# Copyright 2007-2023 The Python Markdown Project (v. 1.7 and later)
+# Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
+# Copyright 2004 Manfred Stienstra (the original version)
+
+# License: BSD (see LICENSE.md for details).
+
+"""
+
+Post-processors run on the text of the entire document after is has been serialized into a string.
+Postprocessors should be used to work with the text just before output. Usually, they are used add
+back sections that were extracted in a preprocessor, fix up outgoing encodings, or wrap the whole
+document.
+
+"""
+
+from __future__ import annotations
+
+from collections import OrderedDict
+from typing import TYPE_CHECKING, Any
+from . import util
+import re
+
+if TYPE_CHECKING:  # pragma: no cover
+    from markdown import Markdown
+
+
+def build_postprocessors(md: Markdown, **kwargs: Any) -> util.Registry[Postprocessor]:
+    """ Build the default postprocessors for Markdown. """
+    postprocessors = util.Registry()
+    postprocessors.register(RawHtmlPostprocessor(md), 'raw_html', 30)
+    postprocessors.register(AndSubstitutePostprocessor(), 'amp_substitute', 20)
+    return postprocessors
+
+
+class Postprocessor(util.Processor):
+    """
+    Postprocessors are run after the ElementTree it converted back into text.
+
+    Each Postprocessor implements a `run` method that takes a pointer to a
+    text string, modifies it as necessary and returns a text string.
+
+    Postprocessors must extend `Postprocessor`.
+
+    """
+
+    def run(self, text: str) -> str:
+        """
+        Subclasses of `Postprocessor` should implement a `run` method, which
+        takes the html document as a single text string and returns a
+        (possibly modified) string.
+
+        """
+        pass  # pragma: no cover
+
+
+class RawHtmlPostprocessor(Postprocessor):
+    """ Restore raw html to the document. """
+
+    BLOCK_LEVEL_REGEX = re.compile(r'^\<\/?([^ >]+)')
+
+    def run(self, text: str):
+        """ Iterate over html stash and restore html. """
+        replacements = OrderedDict()
+        for i in range(self.md.htmlStash.html_counter):
+            html = self.stash_to_string(self.md.htmlStash.rawHtmlBlocks[i])
+            if self.isblocklevel(html):
+                replacements["<p>{}</p>".format(
+                    self.md.htmlStash.get_placeholder(i))] = html
+            replacements[self.md.htmlStash.get_placeholder(i)] = html
+
+        def substitute_match(m):
+            key = m.group(0)
+
+            if key not in replacements:
+                if key[3:-4] in replacements:
+                    return f'<p>{ replacements[key[3:-4]] }</p>'
+                else:
+                    return key
+
+            return replacements[key]
+
+        if replacements:
+            base_placeholder = util.HTML_PLACEHOLDER % r'([0-9]+)'
+            pattern = re.compile(f'<p>{ base_placeholder }</p>|{ base_placeholder }')
+            processed_text = pattern.sub(substitute_match, text)
+        else:
+            return text
+
+        if processed_text == text:
+            return processed_text
+        else:
+            return self.run(processed_text)
+
+    def isblocklevel(self, html: str) -> bool:
+        """ Check is block of HTML is block-level. """
+        m = self.BLOCK_LEVEL_REGEX.match(html)
+        if m:
+            if m.group(1)[0] in ('!', '?', '@', '%'):
+                # Comment, PHP etc...
+                return True
+            return self.md.is_block_level(m.group(1))
+        return False
+
+    def stash_to_string(self, text: str) -> str:
+        """ Convert a stashed object to a string. """
+        return str(text)
+
+
+class AndSubstitutePostprocessor(Postprocessor):
+    """ Restore valid entities """
+
+    def run(self, text):
+        text = text.replace(util.AMP_SUBSTITUTE, "&")
+        return text
+
+
+@util.deprecated(
+    "This class is deprecated and will be removed in the future; "
+    "use [`UnescapeTreeprocessor`][markdown.treeprocessors.UnescapeTreeprocessor] instead."
+)
+class UnescapePostprocessor(Postprocessor):
+    """ Restore escaped chars. """
+
+    RE = re.compile(r'{}(\d+){}'.format(util.STX, util.ETX))
+
+    def unescape(self, m):
+        return chr(int(m.group(1)))
+
+    def run(self, text):
+        return self.RE.sub(self.unescape, text)

plugins/markdown_preview/markdown/preprocessors.py

@@ -0,0 +1,91 @@
+# Python Markdown
+
+# A Python implementation of John Gruber's Markdown.
+
+# Documentation: https://python-markdown.github.io/
+# GitHub: https://github.com/Python-Markdown/markdown/
+# PyPI: https://pypi.org/project/Markdown/
+
+# Started by Manfred Stienstra (http://www.dwerg.net/).
+# Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
+# Currently maintained by Waylan Limberg (https://github.com/waylan),
+# Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
+
+# Copyright 2007-2023 The Python Markdown Project (v. 1.7 and later)
+# Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
+# Copyright 2004 Manfred Stienstra (the original version)
+
+# License: BSD (see LICENSE.md for details).
+
+"""
+Preprocessors work on source text before it is broken down into its individual parts.
+This is an excellent place to clean up bad characters or to extract portions for later
+processing that the parser may otherwise choke on.
+"""
+
+from __future__ import annotations
+
+from typing import TYPE_CHECKING, Any
+from . import util
+from .htmlparser import HTMLExtractor
+import re
+
+if TYPE_CHECKING:  # pragma: no cover
+    from markdown import Markdown
+
+
+def build_preprocessors(md: Markdown, **kwargs: Any) -> util.Registry[Preprocessor]:
+    """ Build and return the default set of preprocessors used by Markdown. """
+    preprocessors = util.Registry()
+    preprocessors.register(NormalizeWhitespace(md), 'normalize_whitespace', 30)
+    preprocessors.register(HtmlBlockPreprocessor(md), 'html_block', 20)
+    return preprocessors
+
+
+class Preprocessor(util.Processor):
+    """
+    Preprocessors are run after the text is broken into lines.
+
+    Each preprocessor implements a `run` method that takes a pointer to a
+    list of lines of the document, modifies it as necessary and returns
+    either the same pointer or a pointer to a new list.
+
+    Preprocessors must extend `Preprocessor`.
+
+    """
+    def run(self, lines: list[str]) -> list[str]:
+        """
+        Each subclass of `Preprocessor` should override the `run` method, which
+        takes the document as a list of strings split by newlines and returns
+        the (possibly modified) list of lines.
+
+        """
+        pass  # pragma: no cover
+
+
+class NormalizeWhitespace(Preprocessor):
+    """ Normalize whitespace for consistent parsing. """
+
+    def run(self, lines: list[str]) -> list[str]:
+        source = '\n'.join(lines)
+        source = source.replace(util.STX, "").replace(util.ETX, "")
+        source = source.replace("\r\n", "\n").replace("\r", "\n") + "\n\n"
+        source = source.expandtabs(self.md.tab_length)
+        source = re.sub(r'(?<=\n) +\n', '\n', source)
+        return source.split('\n')
+
+
+class HtmlBlockPreprocessor(Preprocessor):
+    """
+    Remove html blocks from the text and store them for later retrieval.
+
+    The raw HTML is stored in the [`htmlStash`][markdown.util.HtmlStash] of the
+    [`Markdown`][markdown.Markdown] instance.
+    """
+
+    def run(self, lines: list[str]) -> list[str]:
+        source = '\n'.join(lines)
+        parser = HTMLExtractor(self.md)
+        parser.feed(source)
+        parser.close()
+        return ''.join(parser.cleandoc).split('\n')

plugins/markdown_preview/markdown/serializers.py

@@ -0,0 +1,193 @@
+# Add x/html serialization to `Elementree`
+# Taken from ElementTree 1.3 preview with slight modifications
+#
+# Copyright (c) 1999-2007 by Fredrik Lundh.  All rights reserved.
+#
+# fredrik@pythonware.com
+# https://www.pythonware.com/
+#
+# --------------------------------------------------------------------
+# The ElementTree toolkit is
+#
+# Copyright (c) 1999-2007 by Fredrik Lundh
+#
+# By obtaining, using, and/or copying this software and/or its
+# associated documentation, you agree that you have read, understood,
+# and will comply with the following terms and conditions:
+#
+# Permission to use, copy, modify, and distribute this software and
+# its associated documentation for any purpose and without fee is
+# hereby granted, provided that the above copyright notice appears in
+# all copies, and that both that copyright notice and this permission
+# notice appear in supporting documentation, and that the name of
+# Secret Labs AB or the author not be used in advertising or publicity
+# pertaining to distribution of the software without specific, written
+# prior permission.
+#
+# SECRET LABS AB AND THE AUTHOR DISCLAIMS ALL WARRANTIES WITH REGARD
+# TO THIS SOFTWARE, INCLUDING ALL IMPLIED WARRANTIES OF MERCHANT-
+# ABILITY AND FITNESS.  IN NO EVENT SHALL SECRET LABS AB OR THE AUTHOR
+# BE LIABLE FOR ANY SPECIAL, INDIRECT OR CONSEQUENTIAL DAMAGES OR ANY
+# DAMAGES WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS,
+# WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS
+# ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
+# OF THIS SOFTWARE.
+# --------------------------------------------------------------------
+
+"""
+Python-Markdown provides two serializers which render [`ElementTree.Element`][xml.etree.ElementTree.Element]
+objects to a string of HTML. Both functions wrap the same underlying code with only a few minor
+differences as outlined below:
+
+1. Empty (self-closing) tags are rendered as `<tag>` for HTML and as `<tag />` for XHTML.
+2. Boolean attributes are rendered as `attrname` for HTML and as `attrname="attrname"` for XHTML.
+"""
+
+from __future__ import annotations
+
+from xml.etree.ElementTree import ProcessingInstruction
+from xml.etree.ElementTree import Comment, ElementTree, Element, QName, HTML_EMPTY
+import re
+
+__all__ = ['to_html_string', 'to_xhtml_string']
+
+RE_AMP = re.compile(r'&(?!(?:\#[0-9]+|\#x[0-9a-f]+|[0-9a-z]+);)', re.I)
+
+
+def _raise_serialization_error(text):  # pragma: no cover
+    raise TypeError(
+        "cannot serialize {!r} (type {})".format(text, type(text).__name__)
+        )
+
+
+def _escape_cdata(text):
+    # escape character data
+    try:
+        # it's worth avoiding do-nothing calls for strings that are
+        # shorter than 500 character, or so.  assume that's, by far,
+        # the most common case in most applications.
+        if "&" in text:
+            # Only replace & when not part of an entity
+            text = RE_AMP.sub('&amp;', text)
+        if "<" in text:
+            text = text.replace("<", "&lt;")
+        if ">" in text:
+            text = text.replace(">", "&gt;")
+        return text
+    except (TypeError, AttributeError):  # pragma: no cover
+        _raise_serialization_error(text)
+
+
+def _escape_attrib(text):
+    # escape attribute value
+    try:
+        if "&" in text:
+            # Only replace & when not part of an entity
+            text = RE_AMP.sub('&amp;', text)
+        if "<" in text:
+            text = text.replace("<", "&lt;")
+        if ">" in text:
+            text = text.replace(">", "&gt;")
+        if "\"" in text:
+            text = text.replace("\"", "&quot;")
+        if "\n" in text:
+            text = text.replace("\n", "&#10;")
+        return text
+    except (TypeError, AttributeError):  # pragma: no cover
+        _raise_serialization_error(text)
+
+
+def _escape_attrib_html(text):
+    # escape attribute value
+    try:
+        if "&" in text:
+            # Only replace & when not part of an entity
+            text = RE_AMP.sub('&amp;', text)
+        if "<" in text:
+            text = text.replace("<", "&lt;")
+        if ">" in text:
+            text = text.replace(">", "&gt;")
+        if "\"" in text:
+            text = text.replace("\"", "&quot;")
+        return text
+    except (TypeError, AttributeError):  # pragma: no cover
+        _raise_serialization_error(text)
+
+
+def _serialize_html(write, elem, format):
+    tag = elem.tag
+    text = elem.text
+    if tag is Comment:
+        write("<!--%s-->" % _escape_cdata(text))
+    elif tag is ProcessingInstruction:
+        write("<?%s?>" % _escape_cdata(text))
+    elif tag is None:
+        if text:
+            write(_escape_cdata(text))
+        for e in elem:
+            _serialize_html(write, e, format)
+    else:
+        namespace_uri = None
+        if isinstance(tag, QName):
+            # `QNAME` objects store their data as a string: `{uri}tag`
+            if tag.text[:1] == "{":
+                namespace_uri, tag = tag.text[1:].split("}", 1)
+            else:
+                raise ValueError('QName objects must define a tag.')
+        write("<" + tag)
+        items = elem.items()
+        if items:
+            items = sorted(items)  # lexical order
+            for k, v in items:
+                if isinstance(k, QName):
+                    # Assume a text only `QName`
+                    k = k.text
+                if isinstance(v, QName):
+                    # Assume a text only `QName`
+                    v = v.text
+                else:
+                    v = _escape_attrib_html(v)
+                if k == v and format == 'html':
+                    # handle boolean attributes
+                    write(" %s" % v)
+                else:
+                    write(' {}="{}"'.format(k, v))
+        if namespace_uri:
+            write(' xmlns="%s"' % (_escape_attrib(namespace_uri)))
+        if format == "xhtml" and tag.lower() in HTML_EMPTY:
+            write(" />")
+        else:
+            write(">")
+            if text:
+                if tag.lower() in ["script", "style"]:
+                    write(text)
+                else:
+                    write(_escape_cdata(text))
+            for e in elem:
+                _serialize_html(write, e, format)
+            if tag.lower() not in HTML_EMPTY:
+                write("</" + tag + ">")
+    if elem.tail:
+        write(_escape_cdata(elem.tail))
+
+
+def _write_html(root, format="html"):
+    assert root is not None
+    data = []
+    write = data.append
+    _serialize_html(write, root, format)
+    return "".join(data)
+
+
+# --------------------------------------------------------------------
+# public functions
+
+
+def to_html_string(element: Element) -> str:
+    """ Serialize element and its children to a string of HTML5. """
+    return _write_html(ElementTree(element).getroot(), format="html")
+
+
+def to_xhtml_string(element: Element) -> str:
+    """ Serialize element and its children to a string of XHTML. """
+    return _write_html(ElementTree(element).getroot(), format="xhtml")

plugins/markdown_preview/markdown/test_tools.py

@@ -0,0 +1,224 @@
+# Python Markdown
+
+# A Python implementation of John Gruber's Markdown.
+
+# Documentation: https://python-markdown.github.io/
+# GitHub: https://github.com/Python-Markdown/markdown/
+# PyPI: https://pypi.org/project/Markdown/
+
+# Started by Manfred Stienstra (http://www.dwerg.net/).
+# Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
+# Currently maintained by Waylan Limberg (https://github.com/waylan),
+# Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
+
+# Copyright 2007-2023 The Python Markdown Project (v. 1.7 and later)
+# Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
+# Copyright 2004 Manfred Stienstra (the original version)
+
+# License: BSD (see LICENSE.md for details).
+
+""" A collection of tools for testing the Markdown code base and extensions. """
+
+from __future__ import annotations
+
+import os
+import sys
+import unittest
+import textwrap
+from typing import Any
+from . import markdown, Markdown, util
+
+try:
+    import tidylib
+except ImportError:
+    tidylib = None
+
+__all__ = ['TestCase', 'LegacyTestCase', 'Kwargs']
+
+
+class TestCase(unittest.TestCase):
+    """
+    A [`unittest.TestCase`][] subclass with helpers for testing Markdown output.
+
+    Define `default_kwargs` as a `dict` of keywords to pass to Markdown for each
+    test. The defaults can be overridden on individual tests.
+
+    The `assertMarkdownRenders` method accepts the source text, the expected
+    output, and any keywords to pass to Markdown. The `default_kwargs` are used
+    except where overridden by `kwargs`. The output and expected output are passed
+    to `TestCase.assertMultiLineEqual`. An `AssertionError` is raised with a diff
+    if the actual output does not equal the expected output.
+
+    The `dedent` method is available to dedent triple-quoted strings if
+    necessary.
+
+    In all other respects, behaves as `unittest.TestCase`.
+    """
+
+    default_kwargs: dict[str, Any] = {}
+    """ Default options to pass to Markdown for each test. """
+
+    def assertMarkdownRenders(self, source, expected, expected_attrs=None, **kwargs):
+        """
+        Test that source Markdown text renders to expected output with given keywords.
+
+        `expected_attrs` accepts a `dict`. Each key should be the name of an attribute
+        on the `Markdown` instance and the value should be the expected value after
+        the source text is parsed by Markdown. After the expected output is tested,
+        the expected value for each attribute is compared against the actual
+        attribute of the `Markdown` instance using `TestCase.assertEqual`.
+        """
+
+        expected_attrs = expected_attrs or {}
+        kws = self.default_kwargs.copy()
+        kws.update(kwargs)
+        md = Markdown(**kws)
+        output = md.convert(source)
+        self.assertMultiLineEqual(output, expected)
+        for key, value in expected_attrs.items():
+            self.assertEqual(getattr(md, key), value)
+
+    def dedent(self, text):
+        """
+        Dedent text.
+        """
+
+        # TODO: If/when actual output ends with a newline, then use:
+        #     return textwrap.dedent(text.strip('/n'))
+        return textwrap.dedent(text).strip()
+
+
+class recursionlimit:
+    """
+    A context manager which temporarily modifies the Python recursion limit.
+
+    The testing framework, coverage, etc. may add an arbitrary number of levels to the depth. To maintain consistency
+    in the tests, the current stack depth is determined when called, then added to the provided limit.
+
+    Example usage:
+
+    ``` python
+    with recursionlimit(20):
+        # test code here
+    ```
+
+    See <https://stackoverflow.com/a/50120316/866026>.
+    """
+
+    def __init__(self, limit):
+        self.limit = util._get_stack_depth() + limit
+        self.old_limit = sys.getrecursionlimit()
+
+    def __enter__(self):
+        sys.setrecursionlimit(self.limit)
+
+    def __exit__(self, type, value, tb):
+        sys.setrecursionlimit(self.old_limit)
+
+
+#########################
+# Legacy Test Framework #
+#########################
+
+
+class Kwargs(dict):
+    """ A `dict` like class for holding keyword arguments. """
+    pass
+
+
+def _normalize_whitespace(text):
+    """ Normalize whitespace for a string of HTML using `tidylib`. """
+    output, errors = tidylib.tidy_fragment(text, options={
+        'drop_empty_paras': 0,
+        'fix_backslash': 0,
+        'fix_bad_comments': 0,
+        'fix_uri': 0,
+        'join_styles': 0,
+        'lower_literals': 0,
+        'merge_divs': 0,
+        'output_xhtml': 1,
+        'quote_ampersand': 0,
+        'newline': 'LF'
+    })
+    return output
+
+
+class LegacyTestMeta(type):
+    def __new__(cls, name, bases, dct):
+
+        def generate_test(infile, outfile, normalize, kwargs):
+            def test(self):
+                with open(infile, encoding="utf-8") as f:
+                    input = f.read()
+                with open(outfile, encoding="utf-8") as f:
+                    # Normalize line endings
+                    # (on Windows, git may have altered line endings).
+                    expected = f.read().replace("\r\n", "\n")
+                output = markdown(input, **kwargs)
+                if tidylib and normalize:
+                    try:
+                        expected = _normalize_whitespace(expected)
+                        output = _normalize_whitespace(output)
+                    except OSError:
+                        self.skipTest("Tidylib's c library not available.")
+                elif normalize:
+                    self.skipTest('Tidylib not available.')
+                self.assertMultiLineEqual(output, expected)
+            return test
+
+        location = dct.get('location', '')
+        exclude = dct.get('exclude', [])
+        normalize = dct.get('normalize', False)
+        input_ext = dct.get('input_ext', '.txt')
+        output_ext = dct.get('output_ext', '.html')
+        kwargs = dct.get('default_kwargs', Kwargs())
+
+        if os.path.isdir(location):
+            for file in os.listdir(location):
+                infile = os.path.join(location, file)
+                if os.path.isfile(infile):
+                    tname, ext = os.path.splitext(file)
+                    if ext == input_ext:
+                        outfile = os.path.join(location, tname + output_ext)
+                        tname = tname.replace(' ', '_').replace('-', '_')
+                        kws = kwargs.copy()
+                        if tname in dct:
+                            kws.update(dct[tname])
+                        test_name = 'test_%s' % tname
+                        if tname not in exclude:
+                            dct[test_name] = generate_test(infile, outfile, normalize, kws)
+                        else:
+                            dct[test_name] = unittest.skip('Excluded')(lambda: None)
+
+        return type.__new__(cls, name, bases, dct)
+
+
+class LegacyTestCase(unittest.TestCase, metaclass=LegacyTestMeta):
+    """
+    A [`unittest.TestCase`][] subclass for running Markdown's legacy file-based tests.
+
+    A subclass should define various properties which point to a directory of
+    text-based test files and define various behaviors/defaults for those tests.
+    The following properties are supported:
+
+    Attributes:
+        location (str): A path to the directory of test files. An absolute path is preferred.
+        exclude (list[str]): A list of tests to exclude. Each test name should comprise the filename
+            without an extension.
+        normalize (bool): A boolean value indicating if the HTML should be normalized. Default: `False`.
+        input_ext (str): A string containing the file extension of input files. Default: `.txt`.
+        output_ext (str): A string containing the file extension of expected output files. Default: `html`.
+        default_kwargs (Kwargs[str, Any]): The default set of keyword arguments for all test files in the directory.
+
+    In addition, properties can be defined for each individual set of test files within
+    the directory. The property should be given the name of the file without the file
+    extension. Any spaces and dashes in the filename should be replaced with
+    underscores. The value of the property should be a `Kwargs` instance which
+    contains the keyword arguments that should be passed to `Markdown` for that
+    test file. The keyword arguments will "update" the `default_kwargs`.
+
+    When the class instance is created, it will walk the given directory and create
+    a separate `Unitttest` for each set of test files using the naming scheme:
+    `test_filename`. One `Unittest` will be run for each set of input and output files.
+    """
+    pass

plugins/markdown_preview/markdown/treeprocessors.py

@@ -0,0 +1,476 @@
+# Python Markdown
+
+# A Python implementation of John Gruber's Markdown.
+
+# Documentation: https://python-markdown.github.io/
+# GitHub: https://github.com/Python-Markdown/markdown/
+# PyPI: https://pypi.org/project/Markdown/
+
+# Started by Manfred Stienstra (http://www.dwerg.net/).
+# Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
+# Currently maintained by Waylan Limberg (https://github.com/waylan),
+# Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
+
+# Copyright 2007-2023 The Python Markdown Project (v. 1.7 and later)
+# Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
+# Copyright 2004 Manfred Stienstra (the original version)
+
+# License: BSD (see LICENSE.md for details).
+
+"""
+Tree processors manipulate the tree created by block processors. They can even create an entirely
+new `ElementTree` object. This is an excellent place for creating summaries, adding collected
+references, or last minute adjustments.
+
+"""
+
+from __future__ import annotations
+
+import re
+import xml.etree.ElementTree as etree
+from typing import TYPE_CHECKING, Any
+from . import util
+from . import inlinepatterns
+
+if TYPE_CHECKING:  # pragma: no cover
+    from markdown import Markdown
+
+
+def build_treeprocessors(md: Markdown, **kwargs: Any) -> util.Registry[Treeprocessor]:
+    """ Build the default  `treeprocessors` for Markdown. """
+    treeprocessors = util.Registry()
+    treeprocessors.register(InlineProcessor(md), 'inline', 20)
+    treeprocessors.register(PrettifyTreeprocessor(md), 'prettify', 10)
+    treeprocessors.register(UnescapeTreeprocessor(md), 'unescape', 0)
+    return treeprocessors
+
+
+def isString(s: Any) -> bool:
+    """ Return `True` if object is a string but not an  [`AtomicString`][markdown.util.AtomicString]. """
+    if not isinstance(s, util.AtomicString):
+        return isinstance(s, str)
+    return False
+
+
+class Treeprocessor(util.Processor):
+    """
+    `Treeprocessor`s are run on the `ElementTree` object before serialization.
+
+    Each `Treeprocessor` implements a `run` method that takes a pointer to an
+    `Element` and modifies it as necessary.
+
+    `Treeprocessors` must extend `markdown.Treeprocessor`.
+
+    """
+    def run(self, root: etree.Element) -> etree.Element | None:
+        """
+        Subclasses of `Treeprocessor` should implement a `run` method, which
+        takes a root `Element`. This method can return another `Element`
+        object, and the existing root `Element` will be replaced, or it can
+        modify the current tree and return `None`.
+        """
+        pass  # pragma: no cover
+
+
+class InlineProcessor(Treeprocessor):
+    """
+    A `Treeprocessor` that traverses a tree, applying inline patterns.
+    """
+
+    def __init__(self, md):
+        self.__placeholder_prefix = util.INLINE_PLACEHOLDER_PREFIX
+        self.__placeholder_suffix = util.ETX
+        self.__placeholder_length = 4 + len(self.__placeholder_prefix) \
+                                      + len(self.__placeholder_suffix)
+        self.__placeholder_re = util.INLINE_PLACEHOLDER_RE
+        self.md = md
+        self.inlinePatterns = md.inlinePatterns
+        self.ancestors = []
+
+    def __makePlaceholder(self, type) -> tuple[str, str]:
+        """ Generate a placeholder """
+        id = "%04d" % len(self.stashed_nodes)
+        hash = util.INLINE_PLACEHOLDER % id
+        return hash, id
+
+    def __findPlaceholder(self, data: str, index: int) -> tuple[str | None, int]:
+        """
+        Extract id from data string, start from index.
+
+        Arguments:
+            data: String.
+            index: Index, from which we start search.
+
+        Returns:
+            Placeholder id and string index, after the found placeholder.
+
+        """
+        m = self.__placeholder_re.search(data, index)
+        if m:
+            return m.group(1), m.end()
+        else:
+            return None, index + 1
+
+    def __stashNode(self, node, type) -> str:
+        """ Add node to stash. """
+        placeholder, id = self.__makePlaceholder(type)
+        self.stashed_nodes[id] = node
+        return placeholder
+
+    def __handleInline(self, data: str, patternIndex: int = 0) -> str:
+        """
+        Process string with inline patterns and replace it with placeholders.
+
+        Arguments:
+            data: A line of Markdown text.
+            patternIndex: The index of the `inlinePattern` to start with.
+
+        Returns:
+            String with placeholders.
+
+        """
+        if not isinstance(data, util.AtomicString):
+            startIndex = 0
+            count = len(self.inlinePatterns)
+            while patternIndex < count:
+                data, matched, startIndex = self.__applyPattern(
+                    self.inlinePatterns[patternIndex], data, patternIndex, startIndex
+                )
+                if not matched:
+                    patternIndex += 1
+        return data
+
+    def __processElementText(self, node: etree.Element, subnode: etree.Element, isText: bool = True):
+        """
+        Process placeholders in `Element.text` or `Element.tail`
+        of Elements popped from `self.stashed_nodes`.
+
+        Arguments:
+            node: Parent node.
+            subnode: Processing node.
+            isText: Boolean variable, True - it's text, False - it's a tail.
+
+        """
+        if isText:
+            text = subnode.text
+            subnode.text = None
+        else:
+            text = subnode.tail
+            subnode.tail = None
+
+        childResult = self.__processPlaceholders(text, subnode, isText)
+
+        if not isText and node is not subnode:
+            pos = list(node).index(subnode) + 1
+        else:
+            pos = 0
+
+        childResult.reverse()
+        for newChild in childResult:
+            node.insert(pos, newChild[0])
+
+    def __processPlaceholders(
+        self,
+        data: str,
+        parent: etree.Element,
+        isText: bool = True
+    ) -> list[tuple[etree.Element, Any]]:
+        """
+        Process string with placeholders and generate `ElementTree` tree.
+
+        Arguments:
+            data: String with placeholders instead of `ElementTree` elements.
+            parent: Element, which contains processing inline data.
+            isText: Boolean variable, True - it's text, False - it's a tail.
+
+        Returns:
+            List with `ElementTree` elements with applied inline patterns.
+
+        """
+        def linkText(text):
+            if text:
+                if result:
+                    if result[-1][0].tail:
+                        result[-1][0].tail += text
+                    else:
+                        result[-1][0].tail = text
+                elif not isText:
+                    if parent.tail:
+                        parent.tail += text
+                    else:
+                        parent.tail = text
+                else:
+                    if parent.text:
+                        parent.text += text
+                    else:
+                        parent.text = text
+        result = []
+        strartIndex = 0
+        while data:
+            index = data.find(self.__placeholder_prefix, strartIndex)
+            if index != -1:
+                id, phEndIndex = self.__findPlaceholder(data, index)
+
+                if id in self.stashed_nodes:
+                    node = self.stashed_nodes.get(id)
+
+                    if index > 0:
+                        text = data[strartIndex:index]
+                        linkText(text)
+
+                    if not isString(node):  # it's Element
+                        for child in [node] + list(node):
+                            if child.tail:
+                                if child.tail.strip():
+                                    self.__processElementText(
+                                        node, child, False
+                                    )
+                            if child.text:
+                                if child.text.strip():
+                                    self.__processElementText(child, child)
+                    else:  # it's just a string
+                        linkText(node)
+                        strartIndex = phEndIndex
+                        continue
+
+                    strartIndex = phEndIndex
+                    result.append((node, self.ancestors[:]))
+
+                else:  # wrong placeholder
+                    end = index + len(self.__placeholder_prefix)
+                    linkText(data[strartIndex:end])
+                    strartIndex = end
+            else:
+                text = data[strartIndex:]
+                if isinstance(data, util.AtomicString):
+                    # We don't want to loose the `AtomicString`
+                    text = util.AtomicString(text)
+                linkText(text)
+                data = ""
+
+        return result
+
+    def __applyPattern(
+        self,
+        pattern: inlinepatterns.Pattern,
+        data: str,
+        patternIndex: int,
+        startIndex: int = 0
+    ) -> tuple[str, bool, int]:
+        """
+        Check if the line fits the pattern, create the necessary
+        elements, add it to `stashed_nodes`.
+
+        Arguments:
+            data: The text to be processed.
+            pattern: The pattern to be checked.
+            patternIndex: Index of current pattern.
+            startIndex: String index, from which we start searching.
+
+        Returns:
+            String with placeholders instead of `ElementTree` elements.
+
+        """
+        new_style = isinstance(pattern, inlinepatterns.InlineProcessor)
+
+        for exclude in pattern.ANCESTOR_EXCLUDES:
+            if exclude.lower() in self.ancestors:
+                return data, False, 0
+
+        if new_style:
+            match = None
+            # Since `handleMatch` may reject our first match,
+            # we iterate over the buffer looking for matches
+            # until we can't find any more.
+            for match in pattern.getCompiledRegExp().finditer(data, startIndex):
+                node, start, end = pattern.handleMatch(match, data)
+                if start is None or end is None:
+                    startIndex += match.end(0)
+                    match = None
+                    continue
+                break
+        else:  # pragma: no cover
+            match = pattern.getCompiledRegExp().match(data[startIndex:])
+            leftData = data[:startIndex]
+
+        if not match:
+            return data, False, 0
+
+        if not new_style:  # pragma: no cover
+            node = pattern.handleMatch(match)
+            start = match.start(0)
+            end = match.end(0)
+
+        if node is None:
+            return data, True, end
+
+        if not isString(node):
+            if not isinstance(node.text, util.AtomicString):
+                # We need to process current node too
+                for child in [node] + list(node):
+                    if not isString(node):
+                        if child.text:
+                            self.ancestors.append(child.tag.lower())
+                            child.text = self.__handleInline(
+                                child.text, patternIndex + 1
+                            )
+                            self.ancestors.pop()
+                        if child.tail:
+                            child.tail = self.__handleInline(
+                                child.tail, patternIndex
+                            )
+
+        placeholder = self.__stashNode(node, pattern.type())
+
+        if new_style:
+            return "{}{}{}".format(data[:start],
+                                   placeholder, data[end:]), True, 0
+        else:  # pragma: no cover
+            return "{}{}{}{}".format(leftData,
+                                     match.group(1),
+                                     placeholder, match.groups()[-1]), True, 0
+
+    def __build_ancestors(self, parent, parents):
+        """Build the ancestor list."""
+        ancestors = []
+        while parent is not None:
+            if parent is not None:
+                ancestors.append(parent.tag.lower())
+            parent = self.parent_map.get(parent)
+        ancestors.reverse()
+        parents.extend(ancestors)
+
+    def run(self, tree: etree.Element, ancestors: list[str] | None = None) -> etree.Element:
+        """Apply inline patterns to a parsed Markdown tree.
+
+        Iterate over `Element`, find elements with inline tag, apply inline
+        patterns and append newly created Elements to tree.  To avoid further
+        processing of string with inline patterns, instead of normal string,
+        use subclass [`AtomicString`][markdown.util.AtomicString]:
+
+            node.text = markdown.util.AtomicString("This will not be processed.")
+
+        Arguments:
+            tree: `Element` object, representing Markdown tree.
+            ancestors: List of parent tag names that precede the tree node (if needed).
+
+        Returns:
+            An element tree object with applied inline patterns.
+
+        """
+        self.stashed_nodes: dict[str, etree.Element] = {}
+
+        # Ensure a valid parent list, but copy passed in lists
+        # to ensure we don't have the user accidentally change it on us.
+        tree_parents = [] if ancestors is None else ancestors[:]
+
+        self.parent_map = {c: p for p in tree.iter() for c in p}
+        stack = [(tree, tree_parents)]
+
+        while stack:
+            currElement, parents = stack.pop()
+
+            self.ancestors = parents
+            self.__build_ancestors(currElement, self.ancestors)
+
+            insertQueue = []
+            for child in currElement:
+                if child.text and not isinstance(
+                    child.text, util.AtomicString
+                ):
+                    self.ancestors.append(child.tag.lower())
+                    text = child.text
+                    child.text = None
+                    lst = self.__processPlaceholders(
+                        self.__handleInline(text), child
+                    )
+                    for item in lst:
+                        self.parent_map[item[0]] = child
+                    stack += lst
+                    insertQueue.append((child, lst))
+                    self.ancestors.pop()
+                if child.tail:
+                    tail = self.__handleInline(child.tail)
+                    dumby = etree.Element('d')
+                    child.tail = None
+                    tailResult = self.__processPlaceholders(tail, dumby, False)
+                    if dumby.tail:
+                        child.tail = dumby.tail
+                    pos = list(currElement).index(child) + 1
+                    tailResult.reverse()
+                    for newChild in tailResult:
+                        self.parent_map[newChild[0]] = currElement
+                        currElement.insert(pos, newChild[0])
+                if len(child):
+                    self.parent_map[child] = currElement
+                    stack.append((child, self.ancestors[:]))
+
+            for element, lst in insertQueue:
+                for i, obj in enumerate(lst):
+                    newChild = obj[0]
+                    element.insert(i, newChild)
+        return tree
+
+
+class PrettifyTreeprocessor(Treeprocessor):
+    """ Add line breaks to the html document. """
+
+    def _prettifyETree(self, elem):
+        """ Recursively add line breaks to `ElementTree` children. """
+
+        i = "\n"
+        if self.md.is_block_level(elem.tag) and elem.tag not in ['code', 'pre']:
+            if (not elem.text or not elem.text.strip()) \
+                    and len(elem) and self.md.is_block_level(elem[0].tag):
+                elem.text = i
+            for e in elem:
+                if self.md.is_block_level(e.tag):
+                    self._prettifyETree(e)
+        if not elem.tail or not elem.tail.strip():
+            elem.tail = i
+
+    def run(self, root: etree.Element) -> None:
+        """ Add line breaks to `Element` object and its children. """
+
+        self._prettifyETree(root)
+        # Do `<br />`'s separately as they are often in the middle of
+        # inline content and missed by `_prettifyETree`.
+        brs = root.iter('br')
+        for br in brs:
+            if not br.tail or not br.tail.strip():
+                br.tail = '\n'
+            else:
+                br.tail = '\n%s' % br.tail
+        # Clean up extra empty lines at end of code blocks.
+        pres = root.iter('pre')
+        for pre in pres:
+            if len(pre) and pre[0].tag == 'code':
+                code = pre[0]
+                # Only prettify code containing text only
+                if not len(code) and code.text is not None:
+                    code.text = util.AtomicString(code.text.rstrip() + '\n')
+
+
+class UnescapeTreeprocessor(Treeprocessor):
+    """ Restore escaped chars """
+
+    RE = re.compile(r'{}(\d+){}'.format(util.STX, util.ETX))
+
+    def _unescape(self, m):
+        return chr(int(m.group(1)))
+
+    def unescape(self, text: str) -> str:
+        return self.RE.sub(self._unescape, text)
+
+    def run(self, root):
+        """ Loop over all elements and unescape all text. """
+        for elem in root.iter():
+            # Unescape text content
+            if elem.text and not elem.tag == 'code':
+                elem.text = self.unescape(elem.text)
+            # Unescape tail content
+            if elem.tail:
+                elem.tail = self.unescape(elem.tail)
+            # Unescape attribute values
+            for key, value in elem.items():
+                elem.set(key, self.unescape(value))

plugins/markdown_preview/markdown/util.py

@@ -0,0 +1,399 @@
+# Python Markdown
+
+# A Python implementation of John Gruber's Markdown.
+
+# Documentation: https://python-markdown.github.io/
+# GitHub: https://github.com/Python-Markdown/markdown/
+# PyPI: https://pypi.org/project/Markdown/
+
+# Started by Manfred Stienstra (http://www.dwerg.net/).
+# Maintained for a few years by Yuri Takhteyev (http://www.freewisdom.org).
+# Currently maintained by Waylan Limberg (https://github.com/waylan),
+# Dmitry Shachnev (https://github.com/mitya57) and Isaac Muse (https://github.com/facelessuser).
+
+# Copyright 2007-2023 The Python Markdown Project (v. 1.7 and later)
+# Copyright 2004, 2005, 2006 Yuri Takhteyev (v. 0.2-1.6b)
+# Copyright 2004 Manfred Stienstra (the original version)
+
+# License: BSD (see LICENSE.md for details).
+
+"""
+This module contains various contacts, classes and functions which get referenced and used
+throughout the code base.
+"""
+
+from __future__ import annotations
+
+import re
+import sys
+import warnings
+from functools import wraps, lru_cache
+from itertools import count
+from typing import TYPE_CHECKING, Generic, Iterator, NamedTuple, TypeVar, overload
+
+if TYPE_CHECKING:  # pragma: no cover
+    from markdown import Markdown
+
+_T = TypeVar('_T')
+
+
+"""
+Constants you might want to modify
+-----------------------------------------------------------------------------
+"""
+
+
+BLOCK_LEVEL_ELEMENTS: list[str] = [
+    # Elements which are invalid to wrap in a `<p>` tag.
+    # See https://w3c.github.io/html/grouping-content.html#the-p-element
+    'address', 'article', 'aside', 'blockquote', 'details', 'div', 'dl',
+    'fieldset', 'figcaption', 'figure', 'footer', 'form', 'h1', 'h2', 'h3',
+    'h4', 'h5', 'h6', 'header', 'hgroup', 'hr', 'main', 'menu', 'nav', 'ol',
+    'p', 'pre', 'section', 'table', 'ul',
+    # Other elements which Markdown should not be mucking up the contents of.
+    'canvas', 'colgroup', 'dd', 'body', 'dt', 'group', 'html', 'iframe', 'li', 'legend',
+    'math', 'map', 'noscript', 'output', 'object', 'option', 'progress', 'script',
+    'style', 'summary', 'tbody', 'td', 'textarea', 'tfoot', 'th', 'thead', 'tr', 'video'
+]
+"""
+List of HTML tags which get treated as block-level elements. Same as the `block_level_elements`
+attribute of the [`Markdown`][markdown.Markdown] class. Generally one should use the
+attribute on the class. This remains for compatibility with older extensions.
+"""
+
+# Placeholders
+STX = '\u0002'
+""" "Start of Text" marker for placeholder templates. """
+ETX = '\u0003'
+""" "End of Text" marker for placeholder templates. """
+INLINE_PLACEHOLDER_PREFIX = STX+"klzzwxh:"
+""" Prefix for inline placeholder template. """
+INLINE_PLACEHOLDER = INLINE_PLACEHOLDER_PREFIX + "%s" + ETX
+""" Placeholder template for stashed inline text. """
+INLINE_PLACEHOLDER_RE = re.compile(INLINE_PLACEHOLDER % r'([0-9]+)')
+""" Regular Expression which matches inline placeholders. """
+AMP_SUBSTITUTE = STX+"amp"+ETX
+""" Placeholder template for HTML entities. """
+HTML_PLACEHOLDER = STX + "wzxhzdk:%s" + ETX
+""" Placeholder template for raw HTML. """
+HTML_PLACEHOLDER_RE = re.compile(HTML_PLACEHOLDER % r'([0-9]+)')
+""" Regular expression which matches HTML placeholders. """
+TAG_PLACEHOLDER = STX + "hzzhzkh:%s" + ETX
+""" Placeholder template for tags. """
+
+
+# Constants you probably do not need to change
+# -----------------------------------------------------------------------------
+
+RTL_BIDI_RANGES = (
+    ('\u0590', '\u07FF'),
+    # Hebrew (0590-05FF), Arabic (0600-06FF),
+    # Syriac (0700-074F), Arabic supplement (0750-077F),
+    # Thaana (0780-07BF), Nko (07C0-07FF).
+    ('\u2D30', '\u2D7F')  # Tifinagh
+)
+
+
+# AUXILIARY GLOBAL FUNCTIONS
+# =============================================================================
+
+
+@lru_cache(maxsize=None)
+def get_installed_extensions():
+    """ Return all entry_points in the `markdown.extensions` group. """
+    if sys.version_info >= (3, 10):
+        from importlib import metadata
+    else:  # `<PY310` use backport
+        import importlib_metadata as metadata
+    # Only load extension entry_points once.
+    return metadata.entry_points(group='markdown.extensions')
+
+
+def deprecated(message: str, stacklevel: int = 2):
+    """
+    Raise a [`DeprecationWarning`][] when wrapped function/method is called.
+
+    Usage:
+
+    ```python
+    @deprecated("This method will be removed in version X; use Y instead.")
+    def some_method():
+        pass
+    ```
+    """
+    def wrapper(func):
+        @wraps(func)
+        def deprecated_func(*args, **kwargs):
+            warnings.warn(
+                f"'{func.__name__}' is deprecated. {message}",
+                category=DeprecationWarning,
+                stacklevel=stacklevel
+            )
+            return func(*args, **kwargs)
+        return deprecated_func
+    return wrapper
+
+
+def parseBoolValue(value: str | None, fail_on_errors: bool = True, preserve_none: bool = False) -> bool | None:
+    """Parses a string representing a boolean value. If parsing was successful,
+       returns `True` or `False`. If `preserve_none=True`, returns `True`, `False`,
+       or `None`. If parsing was not successful, raises `ValueError`, or, if
+       `fail_on_errors=False`, returns `None`."""
+    if not isinstance(value, str):
+        if preserve_none and value is None:
+            return value
+        return bool(value)
+    elif preserve_none and value.lower() == 'none':
+        return None
+    elif value.lower() in ('true', 'yes', 'y', 'on', '1'):
+        return True
+    elif value.lower() in ('false', 'no', 'n', 'off', '0', 'none'):
+        return False
+    elif fail_on_errors:
+        raise ValueError('Cannot parse bool value: %r' % value)
+
+
+def code_escape(text: str) -> str:
+    """HTML escape a string of code."""
+    if "&" in text:
+        text = text.replace("&", "&amp;")
+    if "<" in text:
+        text = text.replace("<", "&lt;")
+    if ">" in text:
+        text = text.replace(">", "&gt;")
+    return text
+
+
+def _get_stack_depth(size=2):
+    """Get current stack depth, performantly.
+    """
+    frame = sys._getframe(size)
+
+    for size in count(size):
+        frame = frame.f_back
+        if not frame:
+            return size
+
+
+def nearing_recursion_limit() -> bool:
+    """Return true if current stack depth is within 100 of maximum limit."""
+    return sys.getrecursionlimit() - _get_stack_depth() < 100
+
+
+# MISC AUXILIARY CLASSES
+# =============================================================================
+
+
+class AtomicString(str):
+    """A string which should not be further processed."""
+    pass
+
+
+class Processor:
+    """ The base class for all processors.
+
+    Attributes:
+        Processor.md: The `Markdown` instance passed in an initialization.
+
+    Arguments:
+        md: The `Markdown` instance this processor is a part of.
+
+    """
+    def __init__(self, md: Markdown | None = None):
+        self.md = md
+
+
+class HtmlStash:
+    """
+    This class is used for stashing HTML objects that we extract
+    in the beginning and replace with place-holders.
+    """
+
+    def __init__(self):
+        """ Create an `HtmlStash`. """
+        self.html_counter = 0  # for counting inline html segments
+        self.rawHtmlBlocks = []
+        self.tag_counter = 0
+        self.tag_data = []  # list of dictionaries in the order tags appear
+
+    def store(self, html: str) -> str:
+        """
+        Saves an HTML segment for later reinsertion.  Returns a
+        placeholder string that needs to be inserted into the
+        document.
+
+        Keyword arguments:
+            html: An html segment.
+
+        Returns:
+            A placeholder string.
+
+        """
+        self.rawHtmlBlocks.append(html)
+        placeholder = self.get_placeholder(self.html_counter)
+        self.html_counter += 1
+        return placeholder
+
+    def reset(self) -> None:
+        """ Clear the stash. """
+        self.html_counter = 0
+        self.rawHtmlBlocks = []
+
+    def get_placeholder(self, key: int) -> str:
+        return HTML_PLACEHOLDER % key
+
+    def store_tag(self, tag: str, attrs: list, left_index: int, right_index: int) -> str:
+        """Store tag data and return a placeholder."""
+        self.tag_data.append({'tag': tag, 'attrs': attrs,
+                              'left_index': left_index,
+                              'right_index': right_index})
+        placeholder = TAG_PLACEHOLDER % str(self.tag_counter)
+        self.tag_counter += 1  # equal to the tag's index in `self.tag_data`
+        return placeholder
+
+
+# Used internally by `Registry` for each item in its sorted list.
+# Provides an easier to read API when editing the code later.
+# For example, `item.name` is more clear than `item[0]`.
+class _PriorityItem(NamedTuple):
+    name: str
+    priority: float
+
+
+class Registry(Generic[_T]):
+    """
+    A priority sorted registry.
+
+    A `Registry` instance provides two public methods to alter the data of the
+    registry: `register` and `deregister`. Use `register` to add items and
+    `deregister` to remove items. See each method for specifics.
+
+    When registering an item, a "name" and a "priority" must be provided. All
+    items are automatically sorted by "priority" from highest to lowest. The
+    "name" is used to remove ("deregister") and get items.
+
+    A `Registry` instance it like a list (which maintains order) when reading
+    data. You may iterate over the items, get an item and get a count (length)
+    of all items. You may also check that the registry contains an item.
+
+    When getting an item you may use either the index of the item or the
+    string-based "name". For example:
+
+        registry = Registry()
+        registry.register(SomeItem(), 'itemname', 20)
+        # Get the item by index
+        item = registry[0]
+        # Get the item by name
+        item = registry['itemname']
+
+    When checking that the registry contains an item, you may use either the
+    string-based "name", or a reference to the actual item. For example:
+
+        someitem = SomeItem()
+        registry.register(someitem, 'itemname', 20)
+        # Contains the name
+        assert 'itemname' in registry
+        # Contains the item instance
+        assert someitem in registry
+
+    The method `get_index_for_name` is also available to obtain the index of
+    an item using that item's assigned "name".
+    """
+
+    def __init__(self):
+        self._data: dict[str, _T] = {}
+        self._priority = []
+        self._is_sorted = False
+
+    def __contains__(self, item: str | _T) -> bool:
+        if isinstance(item, str):
+            # Check if an item exists by this name.
+            return item in self._data.keys()
+        # Check if this instance exists.
+        return item in self._data.values()
+
+    def __iter__(self) -> Iterator[_T]:
+        self._sort()
+        return iter([self._data[k] for k, p in self._priority])
+
+    @overload
+    def __getitem__(self, key: str | int) -> _T:  # pragma: no cover
+        ...
+
+    @overload
+    def __getitem__(self, key: slice) -> Registry[_T]:  # pragma: no cover
+        ...
+
+    def __getitem__(self, key: str | int | slice) -> _T | Registry[_T]:
+        self._sort()
+        if isinstance(key, slice):
+            data: Registry[_T] = Registry()
+            for k, p in self._priority[key]:
+                data.register(self._data[k], k, p)
+            return data
+        if isinstance(key, int):
+            return self._data[self._priority[key].name]
+        return self._data[key]
+
+    def __len__(self) -> int:
+        return len(self._priority)
+
+    def __repr__(self):
+        return '<{}({})>'.format(self.__class__.__name__, list(self))
+
+    def get_index_for_name(self, name: str) -> int:
+        """
+        Return the index of the given name.
+        """
+        if name in self:
+            self._sort()
+            return self._priority.index(
+                [x for x in self._priority if x.name == name][0]
+            )
+        raise ValueError('No item named "{}" exists.'.format(name))
+
+    def register(self, item: _T, name: str, priority: float) -> None:
+        """
+        Add an item to the registry with the given name and priority.
+
+        Arguments:
+            item: The item being registered.
+            name: A string used to reference the item.
+            priority: An integer or float used to sort against all items.
+
+        If an item is registered with a "name" which already exists, the
+        existing item is replaced with the new item. Treat carefully as the
+        old item is lost with no way to recover it. The new item will be
+        sorted according to its priority and will **not** retain the position
+        of the old item.
+        """
+        if name in self:
+            # Remove existing item of same name first
+            self.deregister(name)
+        self._is_sorted = False
+        self._data[name] = item
+        self._priority.append(_PriorityItem(name, priority))
+
+    def deregister(self, name: str, strict: bool = True) -> None:
+        """
+        Remove an item from the registry.
+
+        Set `strict=False` to fail silently. Otherwise a [`ValueError`][] is raised for an unknown `name`.
+        """
+        try:
+            index = self.get_index_for_name(name)
+            del self._priority[index]
+            del self._data[name]
+        except ValueError:
+            if strict:
+                raise
+
+    def _sort(self):
+        """
+        Sort the registry by priority from highest to lowest.
+
+        This method is called internally and should never be explicitly called.
+        """
+        if not self._is_sorted:
+            self._priority.sort(key=lambda item: item.priority, reverse=True)
+            self._is_sorted = True

plugins/markdown_preview/markdown_preview.glade

@@ -26,7 +26,11 @@
     <property name="enable-webrtc">True</property>
   </object>
   <object class="GtkPopover" id="markdown_preview_dialog">
+    <property name="width-request">620</property>
+    <property name="height-request">480</property>
     <property name="can-focus">False</property>
+    <property name="vexpand">True</property>
+    <property name="position">left</property>
     <property name="modal">False</property>
     <property name="transitions-enabled">False</property>
     <property name="constrain-to">none</property>
@@ -34,21 +38,23 @@
       <object class="GtkBox">
         <property name="visible">True</property>
         <property name="can-focus">False</property>
+        <property name="hexpand">True</property>
+        <property name="vexpand">True</property>
         <property name="orientation">vertical</property>
         <child>
           <object class="GtkButtonBox">
             <property name="visible">True</property>
             <property name="can-focus">False</property>
-            <property name="layout-style">start</property>
+            <property name="layout-style">end</property>
             <child>
-              <object class="GtkButton">
+              <object class="GtkToggleButton">
-                <property name="label">gtk-media-play</property>
+                <property name="label">gtk-media-pause</property>
                 <property name="visible">True</property>
                 <property name="can-focus">True</property>
                 <property name="receives-default">True</property>
                 <property name="use-stock">True</property>
                 <property name="always-show-image">True</property>
-                <signal name="clicked" handler="_resume_preview_updates" swapped="no"/>
+                <signal name="toggled" handler="_tggle_preview_updates" swapped="no"/>
               </object>
               <packing>
                 <property name="expand">True</property>
@@ -58,34 +64,17 @@
             </child>
             <child>
               <object class="GtkButton">
-                <property name="label">gtk-media-pause</property>
-                <property name="visible">True</property>
-                <property name="can-focus">True</property>
-                <property name="receives-default">True</property>
-                <property name="use-stock">True</property>
-                <property name="always-show-image">True</property>
-                <signal name="clicked" handler="_pause_preview_updates" swapped="no"/>
-              </object>
-              <packing>
-                <property name="expand">True</property>
-                <property name="fill">True</property>
-                <property name="position">1</property>
-              </packing>
-            </child>
-            <child>
-              <object class="GtkButton">
-                <property name="label" translatable="yes">Settings</property>
                 <property name="visible">True</property>
                 <property name="sensitive">False</property>
                 <property name="can-focus">True</property>
                 <property name="receives-default">True</property>
                 <property name="image">settings_img</property>
-                <signal name="clicked" handler="_handle_ettings" swapped="no"/>
+                <signal name="clicked" handler="_handle_settings" swapped="no"/>
               </object>
               <packing>
                 <property name="expand">True</property>
                 <property name="fill">True</property>
-                <property name="position">2</property>
+                <property name="position">1</property>
               </packing>
             </child>
           </object>
@@ -96,17 +85,30 @@
           </packing>
         </child>
         <child>
-          <object class="WebKitWebView" type-func="webkit_web_view_get_type" id="markdown_view">
+          <object class="GtkScrolledWindow">
-            <property name="width-request">200</property>
-            <property name="height-request">400</property>
             <property name="visible">True</property>
             <property name="can-focus">True</property>
+            <property name="shadow-type">in</property>
+            <child>
+              <object class="GtkViewport">
+                <property name="visible">True</property>
+                <property name="can-focus">False</property>
+                <child>
+                  <object class="WebKitWebView" type-func="webkit_web_view_get_type" id="markdown_view">
+                    <property name="visible">True</property>
+                    <property name="can-focus">False</property>
                     <property name="settings">web_view_settings</property>
                     <property name="is-ephemeral">True</property>
+                    <property name="is-muted">True</property>
+                    <property name="default-content-security-policy">*</property>
                     <child>
                       <placeholder/>
                     </child>
                   </object>
+                </child>
+              </object>
+            </child>
+          </object>
           <packing>
             <property name="expand">True</property>
             <property name="fill">True</property>

plugins/markdown_preview/markdown_template_mixin.py

@@ -0,0 +1,42 @@
+# Python imports
+
+# Lib imports
+
+# Application imports
+
+
+
+class MarkdownTemplateMixin:
+    def wrap_html_to_body(self, html):
+        return f"""\
+<!DOCTYPE html>
+<html lang="en" dir="ltr">
+<head>
+    <meta charset="utf-8">
+    <title>Markdown View</title>
+    <style media="screen">
+        html, body {{
+            display: block;
+            background-color: #32383e00;
+            color: #ffffff;
+            text-wrap: wrap;
+        }}
+        
+        img {{
+            width: 100%;
+            height: auto;
+        }}
+        
+        code {{
+            border: 1px solid #32383e;
+            background-color: #32383e;
+            padding: 4px;
+        }}
+    </style>
+</head>
+<body>
+    {html}
+</body>
+</html>
+
+"""

plugins/markdown_preview/plugin.py

@@ -4,16 +4,20 @@ import os
 # Lib imports
 import gi
 gi.require_version('Gtk', '3.0')
+gi.require_version('Gdk', '3.0')
 gi.require_version('WebKit2', '4.0')
 from gi.repository import Gtk
+from gi.repository import Gdk
 from gi.repository import WebKit2
 
 # Application imports
+import markdown
+from .markdown_template_mixin import MarkdownTemplateMixin
 from plugins.plugin_base import PluginBase
 
 
 
-class Plugin(PluginBase):
+class Plugin(MarkdownTemplateMixin, PluginBase):
     def __init__(self):
         super().__init__()
 
@@ -22,44 +26,77 @@ class Plugin(PluginBase):
         self.path               = os.path.dirname(os.path.realpath(__file__))
         self._GLADE_FILE        = f"{self.path}/markdown_preview.glade"
         
-        WebKit2.WebView()       # Need one initialized for webview to work from glade file
+        self.is_preview_paused  = False
 
 
     def run(self):
+        WebKit2.WebView()       # Need one initialized for webview to work from glade file
+
         self._builder = Gtk.Builder()
         self._builder.add_from_file(self._GLADE_FILE)
         self._connect_builder_signals(self, self._builder)
 
         separator_right         = self._ui_objects[0]
         self._markdown_dialog   = self._builder.get_object("markdown_preview_dialog")
+        self._markdown_view     = self._builder.get_object("markdown_view")
         self._web_view_settings = self._builder.get_object("web_view_settings")
 
+        self._markdown_dialog.set_relative_to(separator_right)
+        self._markdown_view.set_settings(self._web_view_settings)
+        self._markdown_view.set_background_color(Gdk.RGBA(0, 0, 0, 0.0))
+
 
     def generate_reference_ui_element(self):
         ...
 
     def subscribe_to_events(self):
         self._event_system.subscribe("tggle_markdown_preview", self._tggle_markdown_preview)
+        self._event_system.subscribe("set_active_src_view", self._set_active_src_view)
+        self._event_system.subscribe("buffer_changed", self._do_markdown_translate)
 
     def _set_active_src_view(self, source_view):
         self._active_src_view = source_view
         self._buffer          = self._active_src_view.get_buffer()
     
-    def _pause_preview_updates(self):
+    def _handle_settings(self, widget = None, eve = None):
         ...
 
-    def _resume_preview_updates(self):
-        ...
 
-    def _handle_ettings(self):
+    def _buffer_changed_first_load(self, buffer):
-        ...
+        self._buffer = buffer
+        self._do_markdown_translate(buffer)
+
+    def _tggle_preview_updates(self, widget = None, eve = None):
+        self.is_preview_paused = not self.is_preview_paused
+        widget.set_active(self.is_preview_paused)
+
+        if notself.is_preview_paused:
+            self._do_markdown_translate(self._buffer)
 
     def _tggle_markdown_preview(self, widget = None, eve = None):
+        if not self._active_src_view: return
+
         is_visible = self._markdown_dialog.is_visible()
         buffer     = self._active_src_view.get_buffer()
         data       = None
 
         if not is_visible:
             self._markdown_dialog.popup();
+            self._do_markdown_translate(buffer)
         elif not data and is_visible:
             self._markdown_dialog.popdown()
+
+    def _do_markdown_translate(self, buffer):
+        if self.is_preview_paused: return
+
+        is_visible = self._markdown_dialog.is_visible()
+        if not is_visible: return
+
+        start_iter = buffer.get_start_iter()
+        end_iter   = buffer.get_end_iter()
+        text       = buffer.get_text(start_iter, end_iter, include_hidden_chars = False)
+        html       = markdown.markdown(text)
+
+        path       = self._active_src_view.get_current_filepath().get_parent().get_path()
+        data       = self.wrap_html_to_body(html)
+        self._markdown_view.load_html(content = data, base_uri = f"file://{path}/")

plugins/search_replace/plugin.py

@@ -98,6 +98,8 @@ class Plugin(StylingMixin, ReplaceMixin, PluginBase):
         elif not data and is_visible:
             self._search_replace_dialog.popdown()
             self._find_entry.set_text("")
+        else:
+            self._find_entry.grab_focus()
 
 
     def get_search_tag(self, buffer):

plugins/snippets/cson/__init__.py

@@ -0,0 +1,8 @@
+"""
+A Coffescript Object Notation (CSON) parser for Python 2 and Python 3.
+See documentation at https://github.com/avaka/pycson
+"""
+
+from .parser import load, loads
+from .writer import dump, dumps
+from .speg import ParseError

plugins/snippets/cson/parser.py

@@ -0,0 +1,295 @@
+from .speg import peg
+import re, sys
+
+if sys.version_info[0] == 2:
+    _chr = unichr
+else:
+    _chr = chr
+
+def load(fin):
+    return loads(fin.read())
+
+def loads(s):
+    if isinstance(s, bytes):
+        s = s.decode('utf-8')
+    if s.startswith(u'\ufeff'):
+        s = s[1:]
+    return peg(s.replace('\r\n', '\n'), _p_root)
+
+def _p_ws(p):
+    p('[ \t]*')
+
+def _p_nl(p):
+    p(r'([ \t]*(?:#[^\n]*)?\r?\n)+')
+
+def _p_ews(p):
+    with p:
+        p(_p_nl)
+    p(_p_ws)
+
+def _p_id(p):
+    return p(r'[$a-zA-Z_][$0-9a-zA-Z_]*')
+
+_escape_table = {
+    'r': '\r',
+    'n': '\n',
+    't': '\t',
+    'f': '\f',
+    'b': '\b',
+}
+def _p_unescape(p):
+    esc = p('\\\\(?:u[0-9a-fA-F]{4}|[^\n])')
+    if esc[1] == 'u':
+        return _chr(int(esc[2:], 16))
+    return _escape_table.get(esc[1:], esc[1:])
+
+_re_indent = re.compile(r'[ \t]*')
+def _p_block_str(p, c):
+    p(r'{c}{c}{c}'.format(c=c))
+    lines = [['']]
+    with p:
+        while True:
+            s = p(r'(?:{c}(?!{c}{c})|[^{c}\\])*'.format(c=c))
+            l = s.split('\n')
+            lines[-1].append(l[0])
+            lines.extend([x] for x in l[1:])
+            if p(r'(?:\\\n[ \t]*)*'):
+                continue
+            p.commit()
+            lines[-1].append(p(_p_unescape))
+    p(r'{c}{c}{c}'.format(c=c))
+
+    lines = [''.join(l) for l in lines]
+    strip_ws = len(lines) > 1
+    if strip_ws and all(c in ' \t' for c in lines[-1]):
+        lines.pop()
+
+    indent = None
+    for line in lines[1:]:
+        if not line:
+            continue
+        if indent is None:
+            indent = _re_indent.match(line).group(0)
+            continue
+        for i, (c1, c2) in enumerate(zip(indent, line)):
+            if c1 != c2:
+                indent = indent[:i]
+                break
+
+    ind_len = len(indent or '')
+    if strip_ws and all(c in ' \t' for c in lines[0]):
+        lines = [line[ind_len:] for line in lines[1:]]
+    else:
+        lines[1:] = [line[ind_len:] for line in lines[1:]]
+
+    return '\n'.join(lines)
+
+_re_mstr_nl = re.compile(r'(?:[ \t]*\n)+[ \t]*')
+_re_mstr_trailing_nl = re.compile(_re_mstr_nl.pattern + r'\Z')
+def _p_multiline_str(p, c):
+    p('{c}(?!{c}{c})(?:[ \t]*\n[ \t]*)?'.format(c=c))
+    string_parts = []
+    with p:
+        while True:
+            string_parts.append(p(r'[^{c}\\]*'.format(c=c)))
+            if p(r'(?:\\\n[ \t]*)*'):
+                string_parts.append('')
+                continue
+            p.commit()
+            string_parts.append(p(_p_unescape))
+    p(c)
+    string_parts[-1] = _re_mstr_trailing_nl.sub('', string_parts[-1])
+    string_parts[::2] = [_re_mstr_nl.sub(' ', part) for part in string_parts[::2]]
+    return ''.join(string_parts)
+
+def _p_string(p):
+    with p:
+        return p(_p_block_str, '"')
+    with p:
+        return p(_p_block_str, "'")
+    with p:
+        return p(_p_multiline_str, '"')
+    return p(_p_multiline_str, "'")
+
+def _p_array_value(p):
+    with p:
+        p(_p_nl)
+        return p(_p_object)
+    with p:
+        p(_p_ws)
+        return p(_p_line_object)
+    p(_p_ews)
+    return p(_p_simple_value)
+
+def _p_key(p):
+    with p:
+        return p(_p_id)
+    return p(_p_string)
+
+def _p_flow_kv(p):
+    k = p(_p_key)
+    p(_p_ews)
+    p(':')
+    with p:
+        p(_p_nl)
+        return k, p(_p_object)
+    with p:
+        p(_p_ws)
+        return k, p(_p_line_object)
+    p(_p_ews)
+    return k, p(_p_simple_value)
+
+def _p_flow_obj_sep(p):
+    with p:
+        p(_p_ews)
+        p(',')
+        p(_p_ews)
+        return
+
+    p(_p_nl)
+    p(_p_ws)
+
+def _p_simple_value(p):
+    with p:
+        p('null')
+        return None
+
+    with p:
+        p('false')
+        return False
+    with p:
+        p('true')
+        return True
+
+    with p:
+        return int(p('0b[01]+')[2:], 2)
+    with p:
+        return int(p('0o[0-7]+')[2:], 8)
+    with p:
+        return int(p('0x[0-9a-fA-F]+')[2:], 16)
+    with p:
+        return float(p(r'-?(?:[1-9][0-9]*|0)?\.[0-9]+(?:[Ee][\+-]?[0-9]+)?|(?:[1-9][0-9]*|0)(?:\.[0-9]+)?[Ee][\+-]?[0-9]+'))
+    with p:
+        return int(p('-?[1-9][0-9]*|0'), 10)
+
+    with p:
+        return p(_p_string)
+
+    with p:
+        p(r'\[')
+        r = []
+        with p:
+            p.set('I', '')
+            r.append(p(_p_array_value))
+            with p:
+                while True:
+                    with p:
+                        p(_p_ews)
+                        p(',')
+                        rr = p(_p_array_value)
+                    if not p:
+                        p(_p_nl)
+                        with p:
+                            rr = p(_p_object)
+                        if not p:
+                            p(_p_ews)
+                            rr = p(_p_simple_value)
+                    r.append(rr)
+                    p.commit()
+            with p:
+                p(_p_ews)
+                p(',')
+        p(_p_ews)
+        p(r'\]')
+        return r
+
+    p(r'\{')
+
+    r = {}
+    p(_p_ews)
+    with p:
+        p.set('I', '')
+        k, v = p(_p_flow_kv)
+        r[k] = v
+        with p:
+            while True:
+                p(_p_flow_obj_sep)
+                k, v = p(_p_flow_kv)
+                r[k] = v
+                p.commit()
+        p(_p_ews)
+        with p:
+            p(',')
+            p(_p_ews)
+    p(r'\}')
+    return r
+
+def _p_line_kv(p):
+    k = p(_p_key)
+    p(_p_ws)
+    p(':')
+    p(_p_ws)
+    with p:
+        p(_p_nl)
+        p(p.get('I'))
+        return k, p(_p_indented_object)
+    with p:
+        return k, p(_p_line_object)
+    with p:
+        return k, p(_p_simple_value)
+    p(_p_nl)
+    p(p.get('I'))
+    p('[ \t]')
+    p(_p_ws)
+    return k, p(_p_simple_value)
+
+def _p_line_object(p):
+    k, v = p(_p_line_kv)
+    r = { k: v }
+    with p:
+        while True:
+            p(_p_ws)
+            p(',')
+            p(_p_ws)
+            k, v = p(_p_line_kv)
+            r[k] = v # uniqueness
+            p.commit()
+    return r
+
+def _p_object(p):
+    p.set('I', p.get('I') + p('[ \t]*'))
+    r = p(_p_line_object)
+    with p:
+        while True:
+            p(_p_ws)
+            with p:
+                p(',')
+            p(_p_nl)
+            p(p.get('I'))
+            rr = p(_p_line_object)
+            r.update(rr) # unqueness
+            p.commit()
+    return r
+
+def _p_indented_object(p):
+    p.set('I', p.get('I') + p('[ \t]'))
+    return p(_p_object)
+
+def _p_root(p):
+    with p:
+        p(_p_nl)
+
+    with p:
+        p.set('I', '')
+        r = p(_p_object)
+        p(_p_ws)
+        with p:
+            p(',')
+
+    if not p:
+        p(_p_ws)
+        r = p(_p_simple_value)
+
+    p(_p_ews)
+    p(p.eof)
+    return r

plugins/snippets/cson/speg/__init__.py

@@ -0,0 +1,15 @@
+from .errors import ParseError, ExpectedExpr, UnexpectedExpr, SemanticFailure
+from .peg import Parser
+from .rules import eof
+
+def peg(text, root_rule):
+    p = Parser(text)
+    return p(root_rule)
+
+def parse(text, root_rule):
+    p = Parser(text)
+    return p.parse(root_rule)
+
+def hidden(fn):
+    fn._speg_hidden = True
+    return fn

plugins/snippets/cson/speg/errors.py

@@ -0,0 +1,66 @@
+from .rules import rule_to_str
+
+class ExpectedExpr:
+    def __init__(self, expr, callstack):
+        self.expr = expr
+        self.callstack = callstack
+
+class UnexpectedExpr:
+    def __init__(self, end_pos, rule, callstack):
+        self.end_pos = end_pos
+        self.rule = rule
+        self.callstack = callstack
+
+class SemanticFailure:
+    def __init__(self, args, kw, callstack):
+        self.args = args
+        self.kw = kw
+        self.callstack = callstack
+
+class ParseError(RuntimeError):
+    def __init__(self, message, text, start_pos, end_pos, failures):
+        self.message = message
+        self.text = text
+        self.start_pos = start_pos
+        self.end_pos = end_pos
+        self.failures = failures
+
+    def __str__(self):
+        return 'at {}:{}: {}'.format(
+            self.start_pos.line, self.start_pos.col, self.message)
+
+def _first(iterable):
+    return next(iterable, None)
+
+def raise_parsing_error(text, position, failures):
+    end_pos = position
+    msg = []
+
+    sema = _first(f for f in failures if isinstance(f, SemanticFailure))
+    if sema is not None:
+        msg.append(sema.args[0])
+    else:
+        unexps = [f for f in failures if isinstance(f, UnexpectedExpr)]
+        if unexps:
+            unexp = min(unexps,
+                key=lambda f: f.end_pos.offset - position.offset)
+            end_pos = unexp.end_pos
+            msg.append('unexpected {}'.format(rule_to_str(unexp.rule)))
+
+        exps = [f for f in failures if isinstance(f, ExpectedExpr)]
+        if exps:
+            exp_syms = set()
+            for f in exps:
+                r = _first(se.fn for se in f.callstack
+                    if se.position == position and not getattr(se.fn, '_speg_hidden', False))
+                if r is None:
+                    r = f.expr
+                exp_syms.add(rule_to_str(r))
+            exp_strs = sorted(exp_syms)
+
+            if len(exp_strs) == 1:
+                msg.append('expected {}'.format(exp_strs[0]))
+            else:
+                msg.append('expected one of {}'.format(', '.join(exp_strs)))
+
+    raise ParseError('; '.join(msg), text, position, end_pos, failures)

plugins/snippets/cson/speg/peg.py

@@ -0,0 +1,195 @@
+import re
+import sys
+
+import six
+
+from .errors import ExpectedExpr, UnexpectedExpr, SemanticFailure, raise_parsing_error
+from .position import Position, get_line_at_position
+from .rules import eof
+
+class _ParseBacktrackError(BaseException):
+    pass
+
+class _PegState:
+    def __init__(self, position):
+        self.position = position
+        self.vars = {}
+        self.committed = False
+        self.failure_pos = None
+        self.failures = None
+
+class Node:
+    def __init__(self, value, start_pos, end_pos):
+        self.value = value
+        self.start_pos = start_pos
+        self.end_pos = end_pos
+
+class Parser:
+    def __init__(self, text):
+        self._text = text
+
+    def __call__(self, r, *args, **kw):
+        return self._parse(lambda p: p(r, *args, **kw))
+
+    def parse(self, r, *args, **kw):
+        return self._parse(lambda p: p.consume(r, *args, **kw))
+
+    def _parse(self, fn):
+        p = ParsingState(self._text)
+        try:
+            return fn(p)
+        except _ParseBacktrackError:
+            assert len(p._states) == 1
+            assert p._states[0].failure_pos is not None
+            raise_parsing_error(self._text, p._states[0].failure_pos, p._states[0].failures)
+
+class CallstackEntry:
+    def __init__(self, position, fn, args, kw):
+        self.position = position
+        self.fn = fn
+        self.args = args
+        self.kw = kw
+
+    def __repr__(self):
+        return '{} at {}:{}'.format(self.fn.__name__, self.position.line, self.position.col)
+
+class ParsingState(object):
+    def __init__(self, s):
+        self._s = s
+        self._states = [_PegState(Position())]
+        self._re_cache = {}
+        self._callstack = []
+
+    def __call__(self, r, *args, **kw):
+        st = self._states[-1]
+        if r is eof:
+            if st.position.offset != len(self._s):
+                self._raise(ExpectedExpr, eof)
+            return ''
+        elif isinstance(r, six.string_types):
+            flags = args[0] if args else 0
+            compiled = self._re_cache.get((r, flags))
+            if not compiled:
+                compiled = re.compile(r, flags)
+                self._re_cache[r, flags] = compiled
+            m = compiled.match(self._s[st.position.offset:])
+            if not m:
+                self._raise(ExpectedExpr, r)
+
+            ms = m.group(0)
+            st.position = st.position.advanced_by(ms)
+            return ms
+        else:
+            kw.pop('err', None)
+            self._callstack.append(CallstackEntry(st.position, r, args, kw))
+            try:
+                return r(self, *args, **kw)
+            finally:
+                self._callstack.pop()
+
+    def consume(self, r, *args, **kw):
+        start_pos = self.position()
+        value = self(r, *args, **kw)
+        end_pos = self.position()
+        return Node(value, start_pos, end_pos)
+
+    def position(self):
+        return self._states[-1].position
+
+    def __repr__(self):
+        line, line_offs = get_line_at_position(self._s, self._states[-1].position)
+        return '<speg.ParsingState at {!r}>'.format('{}*{}'.format(line[:line_offs], line[line_offs:]))
+
+    @staticmethod
+    def eof(p):
+        return p(eof)
+
+    def error(self, *args, **kw):
+        if not args:
+            args = ['semantic error']
+        self._raise(SemanticFailure, args, kw)
+
+    def _raise(self, failure_type, *args):
+        st = self._states[-1]
+        if st.failure_pos is None or st.failure_pos <= st.position:
+            failure = failure_type(*args, callstack=tuple(self._callstack))
+            if st.failure_pos != st.position:
+                st.failure_pos = st.position
+                st.failures = set([failure])
+            else:
+                st.failures.add(failure)
+        raise _ParseBacktrackError()
+
+    def get(self, key, default=None):
+        for state in self._states[::-1]:
+            if key in state.vars:
+                return state.vars[key][0]
+        return default
+
+    def set(self, key, value):
+        self._states[-1].vars[key] = value, False
+
+    def set_global(self, key, value):
+        self._states[-1].vars[key] = value, True
+
+    def opt(self, *args, **kw):
+        with self:
+            return self(*args, **kw)
+
+    def not_(self, r, *args, **kw):
+        self._states.append(_PegState(self._states[-1].position))
+        try:
+            n = self.consume(r)
+        except _ParseBacktrackError:
+            consumed = False
+        else:
+            consumed = True
+        finally:
+            self._states.pop()
+
+        if consumed:
+            self._raise(UnexpectedExpr, n.end_pos, r)
+
+    def __enter__(self):
+        self._states[-1].committed = False
+        self._states.append(_PegState(self._states[-1].position))
+
+    def __exit__(self, type, value, traceback):
+        if type is None:
+            self.commit()
+        else:
+            cur = self._states[-1]
+            prev = self._states[-2]
+            assert cur.failure_pos is not None
+
+            if prev.failure_pos is None or prev.failure_pos < cur.failure_pos:
+                prev.failure_pos = cur.failure_pos
+                prev.failures = cur.failures
+            elif prev.failure_pos == cur.failure_pos:
+                prev.failures.update(cur.failures)
+
+        self._states.pop()
+        return type is _ParseBacktrackError
+
+    def commit(self):
+        cur = self._states[-1]
+        prev = self._states[-2]
+
+        for key in cur.vars:
+            val, g = cur.vars[key]
+            if not g:
+                continue
+            if key in prev.vars:
+                prev.vars[key] = val, prev.vars[key][1]
+            else:
+                prev.vars[key] = val, True
+
+        cur.failure_pos = None
+
+        prev.position = cur.position
+        prev.committed = True
+
+    def __nonzero__(self):
+        return self._states[-1].committed
+
+    __bool__ = __nonzero__

plugins/snippets/cson/speg/position.py

@@ -0,0 +1,48 @@
+from functools import total_ordering
+
+@total_ordering
+class Position(object):
+    def __init__(self, offset=0, line=1, col=1):
+        self.offset = offset
+        self.line = line
+        self.col = col
+
+    def advanced_by(self, text):
+        text_len = len(text)
+        offset = self.offset + text_len
+        nl_pos = text.rfind('\n')
+        if nl_pos < 0:
+            line = self.line
+            col = self.col + text_len
+        else:
+            line = self.line + text[:nl_pos].count('\n') + 1
+            col = text_len - nl_pos
+        return Position(offset, line, col)
+
+    def __eq__(self, other):
+        if not isinstance(other, Position):
+            return NotImplemented
+        return self.offset == other.offset
+
+    def __ne__(self, other):
+        return not self == other
+
+    def __hash__(self):
+        return hash(self.offset)
+
+    def __lt__(self, other):
+        if not isinstance(other, Position):
+            return NotImplemented
+        return self.offset < other.offset
+
+    def __repr__(self):
+        return '{}({!r}, {!r}, {!r})'.format(Position.__name__,
+            self.offset, self.line, self.col)
+
+def get_line_at_position(text, pos):
+    suffix = text[pos.offset - pos.col + 1:]
+    stop = suffix.find('\n')
+    if stop == -1:
+        return suffix, pos.col - 1
+    else:
+        return suffix[:stop], pos.col - 1

plugins/snippets/cson/speg/rules.py

@@ -0,0 +1,14 @@
+from six import string_types
+
+class Eof: pass
+eof = Eof()
+
+def rule_to_str(rule):
+    if rule is eof:
+        return 'eof'
+    if isinstance(rule, string_types):
+        return repr(rule)
+    fn_name = rule.__name__
+    if fn_name.startswith('_'):
+        fn_name = fn_name[1:]
+    return '<{}>'.format(fn_name.replace('_', ' '))

plugins/snippets/cson/writer.py

@@ -0,0 +1,191 @@
+import re, json, sys
+
+if sys.version_info[0] == 2:
+    def _is_num(o):
+        return isinstance(o, int) or isinstance(o, long) or isinstance(o, float)
+    def _stringify(o):
+        if isinstance(o, str):
+            return unicode(o)
+        if isinstance(o, unicode):
+            return o
+        return None
+else:
+    def _is_num(o):
+        return isinstance(o, int) or isinstance(o, float)
+    def _stringify(o):
+        if isinstance(o, bytes):
+            return o.decode()
+        if isinstance(o, str):
+            return o
+        return None
+
+_id_re = re.compile(r'[$a-zA-Z_][$0-9a-zA-Z_]*\Z')
+
+class CSONEncoder:
+    def __init__(self, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, sort_keys=False,
+            indent=None, default=None):
+        self._skipkeys = skipkeys
+        self._ensure_ascii = ensure_ascii
+        self._allow_nan = allow_nan
+        self._sort_keys = sort_keys
+        self._indent = ' ' * (indent or 4)
+        self._default = default
+        if check_circular:
+            self._obj_stack = set()
+        else:
+            self._obj_stack = None
+
+    def _format_simple_val(self, o):
+        if o is None:
+            return 'null'
+        if isinstance(o, bool):
+            return 'true' if o else 'false'
+        if _is_num(o):
+            return str(o)
+        s = _stringify(o)
+        if s is not None:
+            return self._escape_string(s)
+        return None
+
+    def _escape_string(self, s):
+        r = json.dumps(s, ensure_ascii=self._ensure_ascii)
+        return u"'{}'".format(r[1:-1].replace("'", r"\'"))
+
+    def _escape_key(self, s):
+        if s is None or isinstance(s, bool) or _is_num(s):
+            s = str(s)
+        s = _stringify(s)
+        if s is None:
+            if self._skipkeys:
+                return None
+            raise TypeError('keys must be a string')
+        if not _id_re.match(s):
+            return self._escape_string(s)
+        return s
+
+    def _push_obj(self, o):
+        if self._obj_stack is not None:
+            if id(o) in self._obj_stack:
+                raise ValueError('Circular reference detected')
+            self._obj_stack.add(id(o))
+
+    def _pop_obj(self, o):
+        if self._obj_stack is not None:
+            self._obj_stack.remove(id(o))
+
+    def _encode(self, o, obj_val=False, indent='', force_flow=False):
+        if isinstance(o, list):
+            if not o:
+                if obj_val:
+                    yield ' []\n'
+                else:
+                    yield indent
+                    yield '[]\n'
+            else:
+                if obj_val:
+                    yield ' [\n'
+                else:
+                    yield indent
+                    yield '[\n'
+                    indent = indent + self._indent
+                self._push_obj(o)
+                for v in o:
+                    for chunk in self._encode(v, obj_val=False, indent=indent, force_flow=True):
+                        yield chunk
+                self._pop_obj(o)
+                yield indent[:-len(self._indent)]
+                yield ']\n'
+        elif isinstance(o, dict):
+            items = [(self._escape_key(k), v) for k, v in o.items()]
+            if self._skipkeys:
+                items = [(k, v) for k, v in items if k is not None]
+            if self._sort_keys:
+                items.sort()
+            if force_flow or not items:
+                if not items:
+                    if obj_val:
+                        yield ' {}\n'
+                    else:
+                        yield indent
+                        yield '{}\n'
+                else:
+                    if obj_val:
+                        yield ' {\n'
+                    else:
+                        yield indent
+                        yield '{\n'
+                        indent = indent + self._indent
+                    self._push_obj(o)
+                    for k, v in items:
+                        yield indent
+                        yield k
+                        yield ':'
+                        for chunk in self._encode(v, obj_val=True, indent=indent + self._indent, force_flow=False):
+                            yield chunk
+                    self._pop_obj(o)
+                    yield indent[:-len(self._indent)]
+                    yield '}\n'
+            else:
+                if obj_val:
+                    yield '\n'
+                self._push_obj(o)
+                for k, v in items:
+                    yield indent
+                    yield k
+                    yield ':'
+                    for chunk in self._encode(v, obj_val=True, indent=indent + self._indent, force_flow=False):
+                        yield chunk
+                self._pop_obj(o)
+        else:
+            v = self._format_simple_val(o)
+            if v is None:
+                self._push_obj(o)
+                v = self.default(o)
+                for chunk in self._encode(v, obj_val=obj_val, indent=indent, force_flow=force_flow):
+                    yield chunk
+                self._pop_obj(o)
+            else:
+                if obj_val:
+                    yield ' '
+                else:
+                    yield indent
+                yield v
+                yield '\n'
+
+    def iterencode(self, o):
+        return self._encode(o)
+
+    def encode(self, o):
+        return ''.join(self.iterencode(o))
+
+    def default(self, o):
+        if self._default is None:
+            raise TypeError('Cannot serialize an object of type {}'.format(type(o).__name__))
+        return self._default(o)
+
+def dump(obj, fp, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, cls=None,
+        indent=None, default=None, sort_keys=False, **kw):
+    if indent is None and cls is None:
+        return json.dump(obj, fp, skipkeys=skipkeys, ensure_ascii=ensure_ascii, check_circular=check_circular,
+            allow_nan=allow_nan, default=default, sort_keys=sort_keys, separators=(',', ':'))
+
+    if cls is None:
+        cls = CSONEncoder
+    encoder = cls(skipkeys=skipkeys, ensure_ascii=ensure_ascii, check_circular=check_circular,
+        allow_nan=allow_nan, sort_keys=sort_keys, indent=indent, default=default, **kw)
+
+    for chunk in encoder.iterencode(obj):
+        fp.write(chunk)
+
+def dumps(obj, skipkeys=False, ensure_ascii=True, check_circular=True, allow_nan=True, cls=None, indent=None,
+        default=None, sort_keys=False, **kw):
+    if indent is None and cls is None:
+        return json.dumps(obj, skipkeys=skipkeys, ensure_ascii=ensure_ascii, check_circular=check_circular,
+            allow_nan=allow_nan, default=default, sort_keys=sort_keys, separators=(',', ':'))
+
+    if cls is None:
+        cls = CSONEncoder
+    encoder = cls(skipkeys=skipkeys, ensure_ascii=ensure_ascii, check_circular=check_circular,
+        allow_nan=allow_nan, sort_keys=sort_keys, indent=indent, default=default, **kw)
+
+    return encoder.encode(obj)

plugins/snippets/manifest.json

@@ -6,7 +6,7 @@
         "support": "",
         "requests": {
             "pass_events": "true",
-            "bind_keys": ["Snippets||show_snippets_ui:<Control>f"]
+            "bind_keys": ["Snippets||show_snippets_ui:<Control>i"]
         }
     }
 }

plugins/snippets/plugin.py

@@ -7,6 +7,7 @@ from gi.repository import Gtk
 
 # Application imports
 from plugins.plugin_base import PluginBase
+from . import cson
 
 
 
@@ -16,16 +17,86 @@ class Plugin(PluginBase):
 
         self.name                 = "Snippets"  # NOTE: Need to remove after establishing private bidirectional 1-1 message bus
                                                 #       where self.name should not be needed for message comms
+        self.snippet_data         = None
+        self.file_type            = None
+        self.active_snippit_group = None
+        self.snippit_groups       = []
+        self.snippit_prefixes     = []
+        self.snippit_group_keys   = []
 
 
     def generate_reference_ui_element(self):
-        button = Gtk.Button(label=self.name)
-        button.connect("button-release-event", self.send_message)
-        return button
-
-    def run(self):
         ...
 
-    def send_message(self, widget=None, eve=None):
+    def run(self):
-        message = "Hello, World!"
+        with open('snippets.cson', 'rb') as f:
-        event_system.emit("display_message", ("warning", message, None))
+            self.snippet_data   = cson.load(f)
+            self.snippit_groups = self.snippet_data.keys()
+
+    def subscribe_to_events(self):
+        self._event_system.subscribe("set_active_src_view", self._set_active_src_view)
+        self._event_system.subscribe("show_snippets_ui", self._show_snippets_ui)
+        self._event_system.subscribe("buffer_changed_first_load", self._buffer_changed_first_load)
+        self._event_system.subscribe("buffer_changed", self._buffer_changed)
+
+
+    def _set_active_src_view(self, source_view):
+        self._active_src_view = source_view
+        self._buffer          = self._active_src_view.get_buffer()
+        self._tag_table       = self._buffer.get_tag_table()
+        self.file_type        = source_view.get_filetype()
+
+        self.load_target_snippt_group()
+
+    def load_target_snippt_group(self):
+        self.active_snippit_group = None
+        for group in self.snippit_groups:
+            if group in self.file_type:
+                self.active_snippit_group = group
+                break
+
+        if self.active_snippit_group:
+            self.snippit_prefixes.clear()
+            keys = self.snippet_data[self.active_snippit_group].keys()
+            
+            self.snippit_group_keys.clear()
+            for key in keys:
+                self.snippit_group_keys.append(key)
+                prefix = self.snippet_data[self.active_snippit_group][key]["prefix"]
+                self.snippit_prefixes.append(prefix)
+
+    def _buffer_changed_first_load(self, buffer):
+        self._buffer = buffer
+        self._handle_update(buffer)
+
+    def _buffer_changed(self, buffer):
+        self._event_system.emit("pause_event_processing")
+        self._handle_update(buffer)
+        self._event_system.emit("resume_event_processing")
+
+
+    def _show_snippets_ui(self):
+        print(f"Data:  {self.snippit_groups}")
+
+    def _handle_update(self, buffer):
+        if not self.active_snippit_group: return
+
+        end_iter   = buffer.get_iter_at_mark( buffer.get_insert() )
+        start_iter = end_iter.copy()
+        start_iter.backward_word_start()
+
+        matches = []
+        text    = buffer.get_text(start_iter, end_iter, include_hidden_chars = False)
+        for prefix in self.snippit_prefixes:
+            if text in prefix:
+                matches.append(prefix)
+
+        snippits = []
+        for _match in matches:
+            for key in self.snippit_group_keys:
+                prefix = self.snippet_data[self.active_snippit_group][key]["prefix"]
+                if prefix == _match: 
+                    body = self.snippet_data[self.active_snippit_group][key]["body"]
+                    snippits.append(body)
+
+        print(snippits)

plugins/snippets/snippets.cson

@@ -0,0 +1,614 @@
+# Your snippets
+#
+# Atom snippets allow you to enter a simple prefix in the editor and hit tab to
+# expand the prefix into a larger code block with templated values.
+#
+# You can create a new snippet in this file by typing "snip" and then hitting
+# tab.
+#
+# An example CoffeeScript snippet to expand log to console.log:
+#
+# '.source.coffee':
+#   'Console log':
+#     'prefix': 'log'
+#     'body': 'console.log $1'
+#
+# Each scope (e.g. '.source.coffee' above) can only be declared once.
+#
+# This file uses CoffeeScript Object Notation (CSON).
+# If you are unfamiliar with CSON, you can read more about it in the
+# Atom Flight Manual:
+# http://flight-manual.atom.io/using-atom/sections/basic-customization/#_cson
+
+
+###    HTML SNIPPETS    ###
+'html':
+
+  'HTML Template':
+    'prefix': 'html'
+    'body': """<!DOCTYPE html>
+<html lang="en" dir="ltr">
+<head>
+    <meta charset="utf-8">
+    <title></title>
+    <link rel="shortcut icon" href="fave_icon.png">
+    <link rel="stylesheet" href="resources/css/base.css">
+    <link rel="stylesheet" href="resources/css/main.css">
+</head>
+<body>
+
+
+
+
+
+
+    <script src="resources/js/.js" charset="utf-8"></script>
+    <script src="resources/js/.js" charset="utf-8"></script>
+</body>
+</html>
+"""
+
+  'Canvas Tag':
+    'prefix': 'canvas'
+    'body': """<canvas id="canvas" width="800" height="600" style="border:1px solid #c3c3c3;"></canvas>"""
+
+  'Img Tag':
+    'prefix': 'img'
+    'body': """<img class="" src="" alt="" />"""
+
+  'Br Tag':
+    'prefix': 'br'
+    'body': """<br/>"""
+
+  'Hr Tag':
+    'prefix': 'hr'
+    'body': """<hr/>"""
+
+  'Server Side Events':
+    'prefix': 'sse'
+    'body': """// SSE events if supported
+if(typeof(EventSource) !== "undefined") {
+    let source = new EventSource("resources/php/sse.php");
+    source.onmessage = (event) => {
+        if (event.data === "<yourDataStringToLookFor>") {
+            // code here
+        }
+    };
+} else {
+    console.log("SSE Not Supported In Browser...");
+}
+"""
+
+  'AJAX Template Function':
+    'prefix': 'ajax template'
+    'body': """const doAjax = async (actionPath, data) => {
+    let xhttp = new XMLHttpRequest();
+
+    xhttp.onreadystatechange = function() {
+        if (this.readyState === 4 && this.status === 200) {
+            if (this.responseText != null) {  // this.responseXML if getting XML fata
+                handleReturnData(JSON.parse(this.responseText));
+            } else {
+                console.log("No content returned. Check the file path.");
+            }
+        }
+    };
+
+    xhttp.open("POST", actionPath, true);
+    xhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
+    // Force return to be JSON NOTE: Use application/xml to force XML
+    xhttp.overrideMimeType('application/json');
+    xhttp.send(data);
+}
+"""
+
+  'CSS Message Colors':
+    'prefix': 'css colors'
+    'body': """.error { color: rgb(255, 0, 0); }
+    .warning { color: rgb(255, 168, 0); }
+    .success { color: rgb(136, 204, 39); }
+    """
+
+
+###    JS SNIPPETS    ###
+'js':
+
+  'Server Side Events':
+    'prefix': 'sse'
+    'body': """// SSE events if supported
+if(typeof(EventSource) !== "undefined") {
+    let source = new EventSource("resources/php/sse.php");
+    source.onmessage = (event) => {
+        if (event.data === "<yourDataStringToLookFor>") {
+            // code here
+        }
+    };
+} else {
+    console.log("SSE Not Supported In Browser...");
+}
+"""
+
+  'AJAX Template Function':
+    'prefix': 'ajax template'
+    'body': """const doAjax = async (actionPath, data) => {
+    let xhttp = new XMLHttpRequest();
+
+    xhttp.onreadystatechange = function() {
+        if (this.readyState === 4 && this.status === 200) {
+            if (this.responseText != null) {  // this.responseXML if getting XML fata
+                handleReturnData(JSON.parse(this.responseText));
+            } else {
+                console.log("No content returned. Check the file path.");
+            }
+        }
+    };
+
+    xhttp.open("POST", actionPath, true);
+    xhttp.setRequestHeader("Content-type", "application/x-www-form-urlencoded");
+    // Force return to be JSON NOTE: Use application/xml to force XML
+    xhttp.overrideMimeType('application/json');
+    xhttp.send(data);
+}
+"""
+
+  'SE6 Function':
+    'prefix': 'function se6'
+    'body': """const funcName = (arg = "") => {
+
+    }
+"""
+
+###    CSS SNIPPETS    ###
+'css':
+
+  'CSS Message Colors':
+    'prefix': 'css colors'
+    'body': """.error { color: rgb(255, 0, 0); }
+    .warning { color: rgb(255, 168, 0); }
+    .success { color: rgb(136, 204, 39); }
+    """
+
+###    PHP SNIPPETS    ###
+'php':
+
+  'SSE PHP':
+    'prefix': 'sse php'
+    'body': """<?php
+    // Start the session
+    session_start();
+
+    header('Content-Type: text/event-stream');
+    header('Cache-Control: no-cache');
+
+    echo "data:dataToReturn\\\\n\\\\n";
+
+    flush();
+    ?>
+    """
+
+  'PHP Template':
+    'prefix': 'php'
+    'body': """<?php
+// Start the session
+session_start();
+
+
+// Determin action
+chdir("../../");  // Note: If in resources/php/
+if (isset($_POST['yourPostID'])) {
+    // code here
+} else {
+    $message = "Server: [Error] --> Illegal Access Method!";
+    serverMessage("error", $message);
+}
+?>
+"""
+  'HTML Template':
+    'prefix': 'html'
+    'body': """<!DOCTYPE html>
+<html lang="en" dir="ltr">
+<head>
+    <meta charset="utf-8">
+    <title></title>
+    <link rel="shortcut icon" href="fave_icon.png">
+    <link rel="stylesheet" href="resources/css/base.css">
+    <link rel="stylesheet" href="resources/css/main.css">
+</head>
+<body>
+
+
+
+
+
+
+    <script src="resources/js/.js" charset="utf-8"></script>
+    <script src="resources/js/.js" charset="utf-8"></script>
+</body>
+</html>
+"""
+
+
+###    BASH SNIPPETS    ###
+'bash':
+
+  'Bash or Shell Template':
+    'prefix': 'bash template'
+    'body': """#!/bin/bash
+
+# . CONFIG.sh
+
+# set -o xtrace       ## To debug scripts
+# set -o errexit      ## To exit on error
+# set -o errunset     ## To exit if a variable is referenced but not set
+
+
+function main() {
+    cd "$(dirname "$0")"
+    echo "Working Dir: " $(pwd)
+
+    file="$1"
+    if [ -z "${file}" ]; then
+        echo "ERROR: No file argument supplied..."
+        exit
+    fi
+
+    if [[ -f "${file}" ]]; then
+        echo "SUCCESS: The path and file exists!"
+    else
+        echo "ERROR: The path or file '${file}' does NOT exist..."
+    fi
+}
+main "$@";
+    """
+
+
+  'Bash or Shell Config':
+    'prefix': 'bash config'
+    'body': """#!/bin/bash
+
+    shopt -s expand_aliases
+
+    alias echo="echo -e"
+    """
+
+
+###    PYTHON SNIPPETS    ###
+'python':
+
+  'Glade __main__ Class Template':
+    'prefix': 'glade __main__ class'
+    'body': """#!/usr/bin/python3
+
+
+# Python imports
+import argparse
+import faulthandler
+import traceback
+import signal
+from setproctitle import setproctitle
+
+# Lib imports
+import gi
+gi.require_version('Gtk', '3.0')
+from gi.repository import Gtk
+from gi.repository import GLib
+
+# Application imports
+from app import Application
+
+
+def run():
+    try:
+        setproctitle('<replace this>')
+        faulthandler.enable()  # For better debug info
+
+        GLib.unix_signal_add(GLib.PRIORITY_DEFAULT, signal.SIGINT, Gtk.main_quit)
+
+        parser = argparse.ArgumentParser()
+        # Add long and short arguments
+        parser.add_argument("--debug", "-d", default="false", help="Do extra console messaging.")
+        parser.add_argument("--trace-debug", "-td", default="false", help="Disable saves, ignore IPC lock, do extra console messaging.")
+        parser.add_argument("--no-plugins", "-np", default="false", help="Do not load plugins.")
+
+        parser.add_argument("--new-tab", "-t", default="", help="Open a file into new tab.")
+        parser.add_argument("--new-window", "-w", default="", help="Open a file into a new window.")
+
+        # Read arguments (If any...)
+        args, unknownargs = parser.parse_known_args()
+
+        main = Application(args, unknownargs)
+        Gtk.main()
+    except Exception as e:
+        traceback.print_exc()
+        quit()
+
+
+if __name__ == "__main__":
+    ''' Set process title, get arguments, and create GTK main thread. '''
+    run()
+
+
+    """
+
+
+  'Glade __main__ Testing Template':
+    'prefix': 'glade testing class'
+    'body': """#!/usr/bin/python3
+
+
+# Python imports
+import traceback
+import faulthandler
+import signal
+
+# Lib imports
+import gi
+gi.require_version('Gtk', '3.0')
+from gi.repository import Gtk
+from gi.repository import GLib
+
+# Application imports
+
+
+app_name = "Gtk Quick Test"
+
+
+class Application(Gtk.ApplicationWindow):
+    def __init__(self):
+        super(Application, self).__init__()
+        self._setup_styling()
+        self._setup_signals()
+        self._load_widgets()
+
+        self.add(Gtk.Box())
+
+        self.show_all()
+
+
+    def _setup_styling(self):
+        self.set_default_size(1670, 830)
+        self.set_title(f"{app_name}")
+        # self.set_icon_from_file( settings.get_window_icon() )
+        self.set_gravity(5)  # 5 = CENTER
+        self.set_position(1) # 1 = CENTER, 4 = CENTER_ALWAYS
+
+    def _setup_signals(self):
+        self.connect("delete-event", Gtk.main_quit)
+
+
+    def _load_widgets(self):
+        ...
+
+
+
+
+def run():
+    try:
+        faulthandler.enable()  # For better debug info
+        GLib.unix_signal_add(GLib.PRIORITY_DEFAULT, signal.SIGINT, Gtk.main_quit)
+
+        main = Application()
+        Gtk.main()
+    except Exception as e:
+        traceback.print_exc()
+        quit()
+
+
+if __name__ == "__main__":
+    ''' Set process title, get arguments, and create GTK main thread. '''
+    run()
+
+
+    """
+
+
+  'Glade _init_ Class Template':
+    'prefix': 'glade __init__ class'
+    'body': """# Python imports
+import inspect
+
+
+# Lib imports
+
+
+# Application imports
+from utils import Settings
+from signal_classes import CrossClassSignals
+
+
+class Main:
+    def __init__(self, args):
+        settings = Settings()
+        builder  = settings.returnBuilder()
+
+        # Gets the methods from the classes and sets to handler.
+        # Then, builder connects to any signals it needs.
+        classes  = [CrossClassSignals(settings)]
+
+        handlers = {}
+        for c in classes:
+            methods = inspect.getmembers(c, predicate=inspect.ismethod)
+            handlers.update(methods)
+
+        builder.connect_signals(handlers)
+        window = settings.createWindow()
+        window.show()
+
+    """
+
+  'Class Method':
+    'prefix': 'def1'
+    'body': """
+    def fname(self):
+        ...
+        """
+
+  'Gtk Class Method':
+    'prefix': 'def2'
+    'body': """
+    def fname(self, widget, eve):
+        ...
+        """
+
+
+  'Python Glade Settings Template':
+    'prefix': 'glade settings class'
+    'body': """# Python imports
+    import os
+
+    # Lib imports
+    import gi, cairo
+    gi.require_version('Gtk', '3.0')
+    gi.require_version('Gdk', '3.0')
+
+    from gi.repository import Gtk
+    from gi.repository import Gdk
+
+
+    # Application imports
+
+
+    class Settings:
+        def __init__(self):
+            self.SCRIPT_PTH = os.path.dirname(os.path.realpath(__file__)) + "/"
+            self.builder = Gtk.Builder()
+            self.builder.add_from_file(self.SCRIPT_PTH + "../resources/Main_Window.glade")
+
+            # 'Filters'
+            self.office = ('.doc', '.docx', '.xls', '.xlsx', '.xlt', '.xltx', '.xlm',
+                                    '.ppt', 'pptx', '.pps', '.ppsx', '.odt', '.rtf')
+            self.vids   = ('.mkv', '.avi', '.flv', '.mov', '.m4v', '.mpg', '.wmv',
+                                                        '.mpeg', '.mp4', '.webm')
+            self.txt    = ('.txt', '.text', '.sh', '.cfg', '.conf')
+            self.music  = ('.psf', '.mp3', '.ogg' , '.flac')
+            self.images = ('.png', '.jpg', '.jpeg', '.gif')
+            self.pdf    = ('.pdf')
+
+
+        def createWindow(self):
+            # Get window and connect signals
+            window = self.builder.get_object("Main_Window")
+            window.connect("delete-event", gtk.main_quit)
+            self.setWindowData(window, False)
+            return window
+
+        def setWindowData(self, window, paintable):
+            screen = window.get_screen()
+            visual = screen.get_rgba_visual()
+
+            if visual != None and screen.is_composited():
+                window.set_visual(visual)
+
+            # bind css file
+            cssProvider  = gtk.CssProvider()
+            cssProvider.load_from_path(self.SCRIPT_PTH + '../resources/stylesheet.css')
+            screen       = Gdk.Screen.get_default()
+            styleContext = Gtk.StyleContext()
+            styleContext.add_provider_for_screen(screen, cssProvider, gtk.STYLE_PROVIDER_PRIORITY_USER)
+
+            window.set_app_paintable(paintable)
+            if paintable:
+                window.connect("draw", self.area_draw)
+
+        def getMonitorData(self):
+            screen = self.builder.get_object("Main_Window").get_screen()
+            monitors = []
+            for m in range(screen.get_n_monitors()):
+                monitors.append(screen.get_monitor_geometry(m))
+
+            for monitor in monitors:
+                print(str(monitor.width) + "x" + str(monitor.height) + "+" + str(monitor.x) + "+" + str(monitor.y))
+
+            return monitors
+
+        def area_draw(self, widget, cr):
+            cr.set_source_rgba(0, 0, 0, 0.54)
+            cr.set_operator(cairo.OPERATOR_SOURCE)
+            cr.paint()
+            cr.set_operator(cairo.OPERATOR_OVER)
+
+
+        def returnBuilder(self):             return self.builder
+
+        # Filter returns
+        def returnOfficeFilter(self):        return self.office
+        def returnVidsFilter(self):          return self.vids
+        def returnTextFilter(self):          return self.txt
+        def returnMusicFilter(self):         return self.music
+        def returnImagesFilter(self):        return self.images
+        def returnPdfFilter(self):           return self.pdf
+
+    """
+
+  'Python Glade CrossClassSignals Template':
+    'prefix': 'glade crossClassSignals class'
+    'body': """# Python imports
+    import threading
+    import subprocess
+    import os
+
+    # Lib imports
+
+    # Application imports
+
+
+    def threaded(fn):
+        def wrapper(*args, **kwargs):
+            threading.Thread(target=fn, args=args, kwargs=kwargs).start()
+
+        return wrapper
+
+
+    class CrossClassSignals:
+        def __init__(self, settings):
+            self.settings       = settings
+            self.builder        = self.settings.returnBuilder()
+
+
+        def getClipboardData(self):
+            proc    = subprocess.Popen(['xclip','-selection', 'clipboard', '-o'], stdout=subprocess.PIPE)
+            retcode = proc.wait()
+            data    = proc.stdout.read()
+            return data.decode("utf-8").strip()
+
+        def setClipboardData(self, data):
+            proc = subprocess.Popen(['xclip','-selection','clipboard'], stdin=subprocess.PIPE)
+            proc.stdin.write(data)
+            proc.stdin.close()
+            retcode = proc.wait()
+
+    """
+
+
+  'Python Glade Generic Template':
+    'prefix': 'glade generic class'
+    'body': """# Python imports
+
+    # Lib imports
+
+    # Application imports
+
+
+    class GenericClass:
+        def __init__(self):
+            super(GenericClass, self).__init__()
+
+            self._setup_styling()
+            self._setup_signals()
+            self._subscribe_to_events()
+            self._load_widgets()
+
+
+        def _setup_styling(self):
+            ...
+
+        def _setup_signals(self):
+            ...
+
+        def _subscribe_to_events(self):
+            event_system.subscribe("handle_file_from_ipc", self.handle_file_from_ipc)
+
+        def _load_widgets(self):
+            ...
+
+    """

src/core/widgets/base/sourceview/source_mark_events_mixin.py

@@ -95,19 +95,14 @@ class MarkEventsMixin:
     
     def _new_line_on_multi_line_markers(self, buffer):
         iter = buffer.get_iter_at_mark( buffer.get_insert() )
-
         self._base_indent(buffer, iter)
         self.insert_indent_handler(buffer, iter)
 
         for mark in self._multi_insert_marks:
             iter = buffer.get_iter_at_mark(mark)
-            iter_copy = iter.copy()
-
             self._base_indent(buffer, iter)
             self.insert_indent_handler(buffer, iter)
 
-        self.end_user_action(buffer)
-
     def insert_indent_handler(self, buffer, iter = None):
         if not iter:
             iter   = buffer.get_iter_at_mark( buffer.get_insert() )

src/core/widgets/base/sourceview/source_view.py

@@ -105,13 +105,14 @@ class SourceView(SourceViewEventsMixin, GtkSource.View):
         for provider in self._completion.get_providers():
             self._completion.remove_provider(provider)
 
-        # TODO: actually load a meaningful provider based on file type...
         file   = self._current_file.get_path()
         buffer = self.get_buffer()
+
         word_completion = GtkSource.CompletionWords.new("word_completion")
         word_completion.register(buffer)
         self._completion.add_provider(word_completion)
 
+        # TODO: actually load a meaningful provider based on file type...
         # example_completion_provider = ExampleCompletionProvider()
         # self._completion.add_provider(example_completion_provider)
 
@@ -180,9 +181,12 @@ class SourceView(SourceViewEventsMixin, GtkSource.View):
         if len(self._multi_insert_marks) > 0:
             if keyname == "BackSpace":
                 self.begin_user_action(buffer)
+
                 with buffer.freeze_notify():
                     GLib.idle_add(self._delete_on_multi_line_markers, *(buffer,))
 
+                self.end_user_action(buffer)
+
             return True
         
         # NOTE: if a plugin recieves the call and handles, it will be the final decider for propigation

src/core/widgets/base/sourceview/source_view_events.py

@@ -7,11 +7,13 @@ from gi.repository import Gtk
 
 # Application imports
 from .source_file_events_mixin import FileEventsMixin
-from .source_marks_events_mixin import MarkEventsMixin
+from .source_mark_events_mixin import MarkEventsMixin
 
 
 
 class SourceViewEventsMixin(MarkEventsMixin, FileEventsMixin):
+    def get_current_filepath(self):
+        return self._current_file
 
     def set_buffer_language(self, buffer, language = "python3"):
         buffer.set_language( self._language_manager.get_language(language) )