def _get_positions_to_highlight(self, document: Document) -> List[Tuple[int, int]]:
"""
Return a list of (row, col) tuples that need to be highlighted.
"""
pos: Optional[int]
# Try for the character under the cursor.
if document.current_char and document.current_char in self.chars:
pos = document.find_matching_bracket_position(
start_pos=document.cursor_position - self.max_cursor_distance,
end_pos=document.cursor_position + self.max_cursor_distance)
# Try for the character before the cursor.
elif (document.char_before_cursor and document.char_before_cursor in
self._closing_braces and document.char_before_cursor in self.chars):
document = Document(document.text, document.cursor_position - 1)
pos = document.find_matching_bracket_position(
start_pos=document.cursor_position - self.max_cursor_distance,
end_pos=document.cursor_position + self.max_cursor_distance)
else:
pos = None
# Return a list of (row, col) tuples that need to be highlighted.
if pos:
pos += document.cursor_position # pos is relative.
row, col = document.translate_index_to_position(pos)
return [(row, col), (document.cursor_position_row, document.cursor_position_col)]
else:
return []
