import string
import re

###$ event <<expand-word>>
###$ win <Alt-slash>
###$ unix <Alt-slash>

class AutoExpand:

menudefs = [
('edit', [
('E_xpand Word', '<<expand-word>>'),
]),
]

wordchars = string.ascii_letters + string.digits + "_"

def __init__(self, editwin):
self.text = editwin.text
self.state = None

def expand_word_event(self, event):
curinsert = self.text.index("insert")
curline = self.text.get("insert linestart", "insert lineend")
if not self.state:
words = self.getwords()
index = 0
else:
words, index, insert, line = self.state
if insert != curinsert or line != curline:
words = self.getwords()
index = 0
if not words:
self.text.bell()
return "break"
word = self.getprevword()
self.text.delete("insert - %d chars" % len(word), "insert")
newword = words[index]
index = (index + 1) % len(words)
if index == 0:
self.text.bell() # Warn we cycled around
self.text.insert("insert", newword)
curinsert = self.text.index("insert")
curline = self.text.get("insert linestart", "insert lineend")
self.state = words, index, curinsert, curline
return "break"

def getwords(self):
word = self.getprevword()
if not word:
return []
before = self.text.get("1.0", "insert wordstart")
wbefore = re.findall(r"\b" + word + r"\w+\b", before)
del before
after = self.text.get("insert wordend", "end")
wafter = re.findall(r"\b" + word + r"\w+\b", after)
del after
if not wbefore and not wafter:
return []
words = []
dict = {}
# search backwards through words before
wbefore.reverse()
for w in wbefore:
if dict.get(w):
continue
words.append(w)
dict[w] = w
# search onwards through words after
for w in wafter:
if dict.get(w):
continue
words.append(w)
dict[w] = w
words.append(word)
return words

def getprevword(self):
line = self.text.get("insert linestart", "insert")
i = len(line)
while i > 0 and line[i-1] in self.wordchars:
i = i-1
return line[i:]