def __init__(self, maxsize=sys.maxint):
"""maxsize -- maximum size of undo list"""
# stacks maintaining (undo,redo) pairs
self._undo_actions = LinkedList()
self._redo_actions = []
# grouping several actions into one
self._group_counter = 0
self._pending_actions = []
# suppress undo/redo while counter > 0
self._suppress_counter = 0
# maximum size undo stack
self._maxsize = maxsize
self._in_progress = False
def normalize_tags(contents, is_stable_tag=lambda tag: False):
"""Normalize open and close tags to ensure proper nesting
This is especially useful for saving to HTML
is_stable_tag -- a function that returns True iff a tag should not
be touched (``stable'').
NOTE: All iterators will be turned to None's. Since were are changing
tag order, iterators no longer make sense
NOTE: assumes we do not have any 'beginstr' and 'endstr' items
"""
open_stack = []
contents = PushIter(contents)
for item in contents:
kind, it, param = item
if kind == "begin":
if is_stable_tag(param):
# if stable tag, skim ahead to see its closing tag
stable_span = LinkedList()
within_closes = set()
for item2 in contents:
stable_span.append(item2)
if item2[0] == "end":
# look at closing tags
if item2[2] == param:
# found matching stable close
break
else:
# record tags that close within the stable_span
within_closes.add(item2[2])
# push items back on contents stream
for item2 in reversed(stable_span):
contents.push(item2)
# define tag classes
# preopen = open_stack
# preopen_inside = preopen's with a close in stable_span
preopen_inside = []
for tag in open_stack:
if tag in within_closes:
preopen_inside.append(tag)
# close preopen_inside
for item2 in _normalize_close(open_stack, preopen_inside):
yield item2
# yield stable open
open_stack.append(param)
yield ("begin", None, param)
# reopen preopen_inside
for tag in preopen_inside:
open_stack.append(tag)
yield ("begin", None, tag)
else:
# yield item unchanged
open_stack.append(param)
yield ("begin", None, param)
elif kind == "end":
for item2 in _normalize_close(open_stack, [param]):
yield item2
else:
yield (kind, None, param)
