Clean up deprecated code and fix multiple issues

- Remove deprecated markdown_preview plugin and re-wrote
- Renamed alt_provider.py under words completer
- Fix words completion provider logic and cache handling
- Fix container orientations (VERTICAL -> HORIZONTAL) and add Separators
- Remove unused Gtk imports from search_replace plugin
- Fix event creation parameter order in source_file.py
- Fix typo in source_view.py (_load_pretify_json -> _load_prettify_json)
- Refactor webkit_ui with new load methods and enhanced settings

plugins/code/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)