| from idlelib.WidgetRedirector import WidgetRedirector |
| from idlelib.Delegator import Delegator |
| |
| class Percolator: |
| |
| def __init__(self, text): |
| # XXX would be nice to inherit from Delegator |
| self.text = text |
| self.redir = WidgetRedirector(text) |
| self.top = self.bottom = Delegator(text) |
| self.bottom.insert = self.redir.register("insert", self.insert) |
| self.bottom.delete = self.redir.register("delete", self.delete) |
| self.filters = [] |
| |
| def close(self): |
| while self.top is not self.bottom: |
| self.removefilter(self.top) |
| self.top = None |
| self.bottom.setdelegate(None); self.bottom = None |
| self.redir.close(); self.redir = None |
| self.text = None |
| |
| def insert(self, index, chars, tags=None): |
| # Could go away if inheriting from Delegator |
| self.top.insert(index, chars, tags) |
| |
| def delete(self, index1, index2=None): |
| # Could go away if inheriting from Delegator |
| self.top.delete(index1, index2) |
| |
| def insertfilter(self, filter): |
| # Perhaps rename to pushfilter()? |
| assert isinstance(filter, Delegator) |
| assert filter.delegate is None |
| filter.setdelegate(self.top) |
| self.top = filter |
| |
| def removefilter(self, filter): |
| # XXX Perhaps should only support popfilter()? |
| assert isinstance(filter, Delegator) |
| assert filter.delegate is not None |
| f = self.top |
| if f is filter: |
| self.top = filter.delegate |
| filter.setdelegate(None) |
| else: |
| while f.delegate is not filter: |
| assert f is not self.bottom |
| f.resetcache() |
| f = f.delegate |
| f.setdelegate(filter.delegate) |
| filter.setdelegate(None) |
| |
| |
| def main(): |
| class Tracer(Delegator): |
| def __init__(self, name): |
| self.name = name |
| Delegator.__init__(self, None) |
| def insert(self, *args): |
| print self.name, ": insert", args |
| self.delegate.insert(*args) |
| def delete(self, *args): |
| print self.name, ": delete", args |
| self.delegate.delete(*args) |
| root = Tk() |
| root.wm_protocol("WM_DELETE_WINDOW", root.quit) |
| text = Text() |
| text.pack() |
| text.focus_set() |
| p = Percolator(text) |
| t1 = Tracer("t1") |
| t2 = Tracer("t2") |
| p.insertfilter(t1) |
| p.insertfilter(t2) |
| root.mainloop() |
| p.removefilter(t2) |
| root.mainloop() |
| p.insertfilter(t2) |
| p.removefilter(t1) |
| root.mainloop() |
| |
| if __name__ == "__main__": |
| from Tkinter import * |
| main() |
