Command to convert SETEXT headers to ATX

Default.sublime-commands

@@ -3,6 +3,10 @@
         "caption": "MarkdownEditing: Fix Underlined Headers",
         "command": "fix_all_underlined_headers"
     },
+    {
+        "caption": "MarkdownEditing: Convert Underlined Headers to ATX",
+        "command": "convert_to_atx"
+    },
     {
         "caption": "MarkdownEditing: Add Missing Link Labels",
         "command": "gather_missing_link_markers"

README.md

@@ -84,6 +84,10 @@ Strikethrough is supported:
 
 Adjusts every setext-style header to add or remove `=` or `-` characters as needed to match the lengths of their header text.
 
+### Convert Underlined Headers to ATX
+
+Converts every setext-style header into an ATX style header. If something is selected only the headers in the selections will be converted, otherwise the conversion will be applied to the whole view.
+
 ### Add Missing Link Labels
 
 Scans document for referenced link usages (`[some link][some_ref]` and `[some link][]`) and checks if they are all defined. If there are undefined link references, command will automatically create their definition snippet at the bottom of the file.

messages/2.0.7.md

@@ -4,4 +4,8 @@ Your _MarkdownEditing_ plugin is updated. Enjoy new version. For any type of fee
 
 * Fenced code blocks now supports Lisp. Fixes #156
 
+## New Features
+
+* Added command to convert underlined (SETEXT) headers to hashed (ATX) headers
+
 [issues]: https://github.com/SublimeText-Markdown/MarkdownEditing/issues

underlined_headers.py

@@ -25,6 +25,13 @@
 	$             # Must fill the while line. Don't match "- list items"
 	''', re.X )
 
+SETEXT_HEADER_RE = re.compile( r'''
+	^(.+)\n
+	( =+ | -+ ) # A run of ---- or ==== underline characters.
+	[ \t]*        # Optional trailing whitespace.
+	$             # Must fill the while line. Don't match "- list items"
+	''', re.X | re.M )
+
 def fix_dashes(view, edit, text_region, dash_region):
 	"""Replaces the underlined "dash" region of a setext header with a run of
 	dashes or equal-signs that match the length of the header text."""
@@ -105,3 +112,25 @@ def run(self, edit):
 
 	def is_enabled(self):
 		return bool(self.view.score_selector(self.view.sel()[0].a, "text.html.markdown"))
+
+class ConvertToAtxCommand(sublime_plugin.TextCommand):
+
+	def run(self, edit, closed=False):
+		regions =  list(self.view.sel())
+		if len(regions) == 1 and regions[0].size() == 0:
+			regions = [sublime.Region(0, self.view.size())]
+		regions.reverse()
+		for region in regions:
+			txt = self.view.substr(region)
+			matches = list(SETEXT_HEADER_RE.finditer(txt))
+			matches.reverse()
+			for m in matches:
+				mreg = sublime.Region(region.begin()+m.start(), region.begin()+m.end())
+				atx = "# "
+				if '-' in m.group(2):
+					atx = "#" + atx
+				closing = atx[::-1] if closed else ""
+				self.view.replace(edit, mreg, atx + m.group(1) + closing)
+
+	def is_enabled(self):
+		return bool(self.view.score_selector(self.view.sel()[0].a, "text.html.markdown"))