1  '''Complete the current word before the cursor with words in the editor.
       2  
       3  Each menu selection or shortcut key selection replaces the word with a
       4  different word with the same prefix. The search for matches begins
       5  before the target and moves toward the top of the editor. It then starts
       6  after the cursor and moves down. It then returns to the original word and
       7  the cycle starts again.
       8  
       9  Changing the current text line or leaving the cursor in a different
      10  place before requesting the next selection causes AutoExpand to reset
      11  its state.
      12  
      13  There is only one instance of Autoexpand.
      14  '''
      15  import re
      16  import string
      17  
      18  
      19  class ESC[4;38;5;81mAutoExpand:
      20      wordchars = string.ascii_letters + string.digits + "_"
      21  
      22      def __init__(self, editwin):
      23          self.text = editwin.text
      24          self.bell = self.text.bell
      25          self.state = None
      26  
      27      def expand_word_event(self, event):
      28          "Replace the current word with the next expansion."
      29          curinsert = self.text.index("insert")
      30          curline = self.text.get("insert linestart", "insert lineend")
      31          if not self.state:
      32              words = self.getwords()
      33              index = 0
      34          else:
      35              words, index, insert, line = self.state
      36              if insert != curinsert or line != curline:
      37                  words = self.getwords()
      38                  index = 0
      39          if not words:
      40              self.bell()
      41              return "break"
      42          word = self.getprevword()
      43          self.text.delete("insert - %d chars" % len(word), "insert")
      44          newword = words[index]
      45          index = (index + 1) % len(words)
      46          if index == 0:
      47              self.bell()            # Warn we cycled around
      48          self.text.insert("insert", newword)
      49          curinsert = self.text.index("insert")
      50          curline = self.text.get("insert linestart", "insert lineend")
      51          self.state = words, index, curinsert, curline
      52          return "break"
      53  
      54      def getwords(self):
      55          "Return a list of words that match the prefix before the cursor."
      56          word = self.getprevword()
      57          if not word:
      58              return []
      59          before = self.text.get("1.0", "insert wordstart")
      60          wbefore = re.findall(r"\b" + word + r"\w+\b", before)
      61          del before
      62          after = self.text.get("insert wordend", "end")
      63          wafter = re.findall(r"\b" + word + r"\w+\b", after)
      64          del after
      65          if not wbefore and not wafter:
      66              return []
      67          words = []
      68          dict = {}
      69          # search backwards through words before
      70          wbefore.reverse()
      71          for w in wbefore:
      72              if dict.get(w):
      73                  continue
      74              words.append(w)
      75              dict[w] = w
      76          # search onwards through words after
      77          for w in wafter:
      78              if dict.get(w):
      79                  continue
      80              words.append(w)
      81              dict[w] = w
      82          words.append(word)
      83          return words
      84  
      85      def getprevword(self):
      86          "Return the word prefix before the cursor."
      87          line = self.text.get("insert linestart", "insert")
      88          i = len(line)
      89          while i > 0 and line[i-1] in self.wordchars:
      90              i = i-1
      91          return line[i:]
      92  
      93  
      94  if __name__ == '__main__':
      95      from unittest import main
      96      main('idlelib.idle_test.test_autoexpand', verbosity=2)