David Scherer | 7aced17 | 2000-08-15 01:13:23 +0000 | [diff] [blame] | 1 | from WidgetRedirector import WidgetRedirector |
| 2 | from Delegator import Delegator |
| 3 | |
| 4 | class Percolator: |
| 5 | |
| 6 | def __init__(self, text): |
| 7 | # XXX would be nice to inherit from Delegator |
| 8 | self.text = text |
| 9 | self.redir = WidgetRedirector(text) |
| 10 | self.top = self.bottom = Delegator(text) |
| 11 | self.bottom.insert = self.redir.register("insert", self.insert) |
| 12 | self.bottom.delete = self.redir.register("delete", self.delete) |
| 13 | self.filters = [] |
| 14 | |
| 15 | def close(self): |
| 16 | while self.top is not self.bottom: |
| 17 | self.removefilter(self.top) |
| 18 | self.top = None |
| 19 | self.bottom.setdelegate(None); self.bottom = None |
| 20 | self.redir.close(); self.redir = None |
| 21 | self.text = None |
| 22 | |
| 23 | def insert(self, index, chars, tags=None): |
| 24 | # Could go away if inheriting from Delegator |
| 25 | self.top.insert(index, chars, tags) |
| 26 | |
| 27 | def delete(self, index1, index2=None): |
| 28 | # Could go away if inheriting from Delegator |
| 29 | self.top.delete(index1, index2) |
| 30 | |
| 31 | def insertfilter(self, filter): |
| 32 | # Perhaps rename to pushfilter()? |
| 33 | assert isinstance(filter, Delegator) |
| 34 | assert filter.delegate is None |
| 35 | filter.setdelegate(self.top) |
| 36 | self.top = filter |
| 37 | |
| 38 | def removefilter(self, filter): |
| 39 | # XXX Perhaps should only support popfilter()? |
| 40 | assert isinstance(filter, Delegator) |
| 41 | assert filter.delegate is not None |
| 42 | f = self.top |
| 43 | if f is filter: |
| 44 | self.top = filter.delegate |
| 45 | filter.setdelegate(None) |
| 46 | else: |
| 47 | while f.delegate is not filter: |
| 48 | assert f is not self.bottom |
| 49 | f.resetcache() |
| 50 | f = f.delegate |
| 51 | f.setdelegate(filter.delegate) |
| 52 | filter.setdelegate(None) |
| 53 | |
| 54 | |
| 55 | def main(): |
| 56 | class Tracer(Delegator): |
| 57 | def __init__(self, name): |
| 58 | self.name = name |
| 59 | Delegator.__init__(self, None) |
| 60 | def insert(self, *args): |
| 61 | print self.name, ": insert", args |
Raymond Hettinger | 931237e | 2003-07-09 18:48:24 +0000 | [diff] [blame] | 62 | self.delegate.insert(*args) |
David Scherer | 7aced17 | 2000-08-15 01:13:23 +0000 | [diff] [blame] | 63 | def delete(self, *args): |
| 64 | print self.name, ": delete", args |
Raymond Hettinger | 931237e | 2003-07-09 18:48:24 +0000 | [diff] [blame] | 65 | self.delegate.delete(*args) |
David Scherer | 7aced17 | 2000-08-15 01:13:23 +0000 | [diff] [blame] | 66 | root = Tk() |
| 67 | root.wm_protocol("WM_DELETE_WINDOW", root.quit) |
| 68 | text = Text() |
| 69 | text.pack() |
| 70 | text.focus_set() |
| 71 | p = Percolator(text) |
| 72 | t1 = Tracer("t1") |
| 73 | t2 = Tracer("t2") |
| 74 | p.insertfilter(t1) |
| 75 | p.insertfilter(t2) |
| 76 | root.mainloop() |
| 77 | p.removefilter(t2) |
| 78 | root.mainloop() |
| 79 | p.insertfilter(t2) |
| 80 | p.removefilter(t1) |
| 81 | root.mainloop() |
| 82 | |
| 83 | if __name__ == "__main__": |
Kurt B. Kaiser | 48b0314 | 2001-07-13 20:00:15 +0000 | [diff] [blame] | 84 | from Tkinter import * |
David Scherer | 7aced17 | 2000-08-15 01:13:23 +0000 | [diff] [blame] | 85 | main() |