|  | import string | 
|  |  | 
|  | from idlelib.delegator import Delegator | 
|  |  | 
|  | # tkinter import not needed because module does not create widgets, | 
|  | # although many methods operate on text widget arguments. | 
|  |  | 
|  | #$ event <<redo>> | 
|  | #$ win <Control-y> | 
|  | #$ unix <Alt-z> | 
|  |  | 
|  | #$ event <<undo>> | 
|  | #$ win <Control-z> | 
|  | #$ unix <Control-z> | 
|  |  | 
|  | #$ event <<dump-undo-state>> | 
|  | #$ win <Control-backslash> | 
|  | #$ unix <Control-backslash> | 
|  |  | 
|  |  | 
|  | class UndoDelegator(Delegator): | 
|  |  | 
|  | max_undo = 1000 | 
|  |  | 
|  | def __init__(self): | 
|  | Delegator.__init__(self) | 
|  | self.reset_undo() | 
|  |  | 
|  | def setdelegate(self, delegate): | 
|  | if self.delegate is not None: | 
|  | self.unbind("<<undo>>") | 
|  | self.unbind("<<redo>>") | 
|  | self.unbind("<<dump-undo-state>>") | 
|  | Delegator.setdelegate(self, delegate) | 
|  | if delegate is not None: | 
|  | self.bind("<<undo>>", self.undo_event) | 
|  | self.bind("<<redo>>", self.redo_event) | 
|  | self.bind("<<dump-undo-state>>", self.dump_event) | 
|  |  | 
|  | def dump_event(self, event): | 
|  | from pprint import pprint | 
|  | pprint(self.undolist[:self.pointer]) | 
|  | print("pointer:", self.pointer, end=' ') | 
|  | print("saved:", self.saved, end=' ') | 
|  | print("can_merge:", self.can_merge, end=' ') | 
|  | print("get_saved():", self.get_saved()) | 
|  | pprint(self.undolist[self.pointer:]) | 
|  | return "break" | 
|  |  | 
|  | def reset_undo(self): | 
|  | self.was_saved = -1 | 
|  | self.pointer = 0 | 
|  | self.undolist = [] | 
|  | self.undoblock = 0  # or a CommandSequence instance | 
|  | self.set_saved(1) | 
|  |  | 
|  | def set_saved(self, flag): | 
|  | if flag: | 
|  | self.saved = self.pointer | 
|  | else: | 
|  | self.saved = -1 | 
|  | self.can_merge = False | 
|  | self.check_saved() | 
|  |  | 
|  | def get_saved(self): | 
|  | return self.saved == self.pointer | 
|  |  | 
|  | saved_change_hook = None | 
|  |  | 
|  | def set_saved_change_hook(self, hook): | 
|  | self.saved_change_hook = hook | 
|  |  | 
|  | was_saved = -1 | 
|  |  | 
|  | def check_saved(self): | 
|  | is_saved = self.get_saved() | 
|  | if is_saved != self.was_saved: | 
|  | self.was_saved = is_saved | 
|  | if self.saved_change_hook: | 
|  | self.saved_change_hook() | 
|  |  | 
|  | def insert(self, index, chars, tags=None): | 
|  | self.addcmd(InsertCommand(index, chars, tags)) | 
|  |  | 
|  | def delete(self, index1, index2=None): | 
|  | self.addcmd(DeleteCommand(index1, index2)) | 
|  |  | 
|  | # Clients should call undo_block_start() and undo_block_stop() | 
|  | # around a sequence of editing cmds to be treated as a unit by | 
|  | # undo & redo.  Nested matching calls are OK, and the inner calls | 
|  | # then act like nops.  OK too if no editing cmds, or only one | 
|  | # editing cmd, is issued in between:  if no cmds, the whole | 
|  | # sequence has no effect; and if only one cmd, that cmd is entered | 
|  | # directly into the undo list, as if undo_block_xxx hadn't been | 
|  | # called.  The intent of all that is to make this scheme easy | 
|  | # to use:  all the client has to worry about is making sure each | 
|  | # _start() call is matched by a _stop() call. | 
|  |  | 
|  | def undo_block_start(self): | 
|  | if self.undoblock == 0: | 
|  | self.undoblock = CommandSequence() | 
|  | self.undoblock.bump_depth() | 
|  |  | 
|  | def undo_block_stop(self): | 
|  | if self.undoblock.bump_depth(-1) == 0: | 
|  | cmd = self.undoblock | 
|  | self.undoblock = 0 | 
|  | if len(cmd) > 0: | 
|  | if len(cmd) == 1: | 
|  | # no need to wrap a single cmd | 
|  | cmd = cmd.getcmd(0) | 
|  | # this blk of cmds, or single cmd, has already | 
|  | # been done, so don't execute it again | 
|  | self.addcmd(cmd, 0) | 
|  |  | 
|  | def addcmd(self, cmd, execute=True): | 
|  | if execute: | 
|  | cmd.do(self.delegate) | 
|  | if self.undoblock != 0: | 
|  | self.undoblock.append(cmd) | 
|  | return | 
|  | if self.can_merge and self.pointer > 0: | 
|  | lastcmd = self.undolist[self.pointer-1] | 
|  | if lastcmd.merge(cmd): | 
|  | return | 
|  | self.undolist[self.pointer:] = [cmd] | 
|  | if self.saved > self.pointer: | 
|  | self.saved = -1 | 
|  | self.pointer = self.pointer + 1 | 
|  | if len(self.undolist) > self.max_undo: | 
|  | ##print "truncating undo list" | 
|  | del self.undolist[0] | 
|  | self.pointer = self.pointer - 1 | 
|  | if self.saved >= 0: | 
|  | self.saved = self.saved - 1 | 
|  | self.can_merge = True | 
|  | self.check_saved() | 
|  |  | 
|  | def undo_event(self, event): | 
|  | if self.pointer == 0: | 
|  | self.bell() | 
|  | return "break" | 
|  | cmd = self.undolist[self.pointer - 1] | 
|  | cmd.undo(self.delegate) | 
|  | self.pointer = self.pointer - 1 | 
|  | self.can_merge = False | 
|  | self.check_saved() | 
|  | return "break" | 
|  |  | 
|  | def redo_event(self, event): | 
|  | if self.pointer >= len(self.undolist): | 
|  | self.bell() | 
|  | return "break" | 
|  | cmd = self.undolist[self.pointer] | 
|  | cmd.redo(self.delegate) | 
|  | self.pointer = self.pointer + 1 | 
|  | self.can_merge = False | 
|  | self.check_saved() | 
|  | return "break" | 
|  |  | 
|  |  | 
|  | class Command: | 
|  | # Base class for Undoable commands | 
|  |  | 
|  | tags = None | 
|  |  | 
|  | def __init__(self, index1, index2, chars, tags=None): | 
|  | self.marks_before = {} | 
|  | self.marks_after = {} | 
|  | self.index1 = index1 | 
|  | self.index2 = index2 | 
|  | self.chars = chars | 
|  | if tags: | 
|  | self.tags = tags | 
|  |  | 
|  | def __repr__(self): | 
|  | s = self.__class__.__name__ | 
|  | t = (self.index1, self.index2, self.chars, self.tags) | 
|  | if self.tags is None: | 
|  | t = t[:-1] | 
|  | return s + repr(t) | 
|  |  | 
|  | def do(self, text): | 
|  | pass | 
|  |  | 
|  | def redo(self, text): | 
|  | pass | 
|  |  | 
|  | def undo(self, text): | 
|  | pass | 
|  |  | 
|  | def merge(self, cmd): | 
|  | return 0 | 
|  |  | 
|  | def save_marks(self, text): | 
|  | marks = {} | 
|  | for name in text.mark_names(): | 
|  | if name != "insert" and name != "current": | 
|  | marks[name] = text.index(name) | 
|  | return marks | 
|  |  | 
|  | def set_marks(self, text, marks): | 
|  | for name, index in marks.items(): | 
|  | text.mark_set(name, index) | 
|  |  | 
|  |  | 
|  | class InsertCommand(Command): | 
|  | # Undoable insert command | 
|  |  | 
|  | def __init__(self, index1, chars, tags=None): | 
|  | Command.__init__(self, index1, None, chars, tags) | 
|  |  | 
|  | def do(self, text): | 
|  | self.marks_before = self.save_marks(text) | 
|  | self.index1 = text.index(self.index1) | 
|  | if text.compare(self.index1, ">", "end-1c"): | 
|  | # Insert before the final newline | 
|  | self.index1 = text.index("end-1c") | 
|  | text.insert(self.index1, self.chars, self.tags) | 
|  | self.index2 = text.index("%s+%dc" % (self.index1, len(self.chars))) | 
|  | self.marks_after = self.save_marks(text) | 
|  | ##sys.__stderr__.write("do: %s\n" % self) | 
|  |  | 
|  | def redo(self, text): | 
|  | text.mark_set('insert', self.index1) | 
|  | text.insert(self.index1, self.chars, self.tags) | 
|  | self.set_marks(text, self.marks_after) | 
|  | text.see('insert') | 
|  | ##sys.__stderr__.write("redo: %s\n" % self) | 
|  |  | 
|  | def undo(self, text): | 
|  | text.mark_set('insert', self.index1) | 
|  | text.delete(self.index1, self.index2) | 
|  | self.set_marks(text, self.marks_before) | 
|  | text.see('insert') | 
|  | ##sys.__stderr__.write("undo: %s\n" % self) | 
|  |  | 
|  | def merge(self, cmd): | 
|  | if self.__class__ is not cmd.__class__: | 
|  | return False | 
|  | if self.index2 != cmd.index1: | 
|  | return False | 
|  | if self.tags != cmd.tags: | 
|  | return False | 
|  | if len(cmd.chars) != 1: | 
|  | return False | 
|  | if self.chars and \ | 
|  | self.classify(self.chars[-1]) != self.classify(cmd.chars): | 
|  | return False | 
|  | self.index2 = cmd.index2 | 
|  | self.chars = self.chars + cmd.chars | 
|  | return True | 
|  |  | 
|  | alphanumeric = string.ascii_letters + string.digits + "_" | 
|  |  | 
|  | def classify(self, c): | 
|  | if c in self.alphanumeric: | 
|  | return "alphanumeric" | 
|  | if c == "\n": | 
|  | return "newline" | 
|  | return "punctuation" | 
|  |  | 
|  |  | 
|  | class DeleteCommand(Command): | 
|  | # Undoable delete command | 
|  |  | 
|  | def __init__(self, index1, index2=None): | 
|  | Command.__init__(self, index1, index2, None, None) | 
|  |  | 
|  | def do(self, text): | 
|  | self.marks_before = self.save_marks(text) | 
|  | self.index1 = text.index(self.index1) | 
|  | if self.index2: | 
|  | self.index2 = text.index(self.index2) | 
|  | else: | 
|  | self.index2 = text.index(self.index1 + " +1c") | 
|  | if text.compare(self.index2, ">", "end-1c"): | 
|  | # Don't delete the final newline | 
|  | self.index2 = text.index("end-1c") | 
|  | self.chars = text.get(self.index1, self.index2) | 
|  | text.delete(self.index1, self.index2) | 
|  | self.marks_after = self.save_marks(text) | 
|  | ##sys.__stderr__.write("do: %s\n" % self) | 
|  |  | 
|  | def redo(self, text): | 
|  | text.mark_set('insert', self.index1) | 
|  | text.delete(self.index1, self.index2) | 
|  | self.set_marks(text, self.marks_after) | 
|  | text.see('insert') | 
|  | ##sys.__stderr__.write("redo: %s\n" % self) | 
|  |  | 
|  | def undo(self, text): | 
|  | text.mark_set('insert', self.index1) | 
|  | text.insert(self.index1, self.chars) | 
|  | self.set_marks(text, self.marks_before) | 
|  | text.see('insert') | 
|  | ##sys.__stderr__.write("undo: %s\n" % self) | 
|  |  | 
|  |  | 
|  | class CommandSequence(Command): | 
|  | # Wrapper for a sequence of undoable cmds to be undone/redone | 
|  | # as a unit | 
|  |  | 
|  | def __init__(self): | 
|  | self.cmds = [] | 
|  | self.depth = 0 | 
|  |  | 
|  | def __repr__(self): | 
|  | s = self.__class__.__name__ | 
|  | strs = [] | 
|  | for cmd in self.cmds: | 
|  | strs.append("    %r" % (cmd,)) | 
|  | return s + "(\n" + ",\n".join(strs) + "\n)" | 
|  |  | 
|  | def __len__(self): | 
|  | return len(self.cmds) | 
|  |  | 
|  | def append(self, cmd): | 
|  | self.cmds.append(cmd) | 
|  |  | 
|  | def getcmd(self, i): | 
|  | return self.cmds[i] | 
|  |  | 
|  | def redo(self, text): | 
|  | for cmd in self.cmds: | 
|  | cmd.redo(text) | 
|  |  | 
|  | def undo(self, text): | 
|  | cmds = self.cmds[:] | 
|  | cmds.reverse() | 
|  | for cmd in cmds: | 
|  | cmd.undo(text) | 
|  |  | 
|  | def bump_depth(self, incr=1): | 
|  | self.depth = self.depth + incr | 
|  | return self.depth | 
|  |  | 
|  |  | 
|  | def _undo_delegator(parent):  # htest # | 
|  | from tkinter import Toplevel, Text, Button | 
|  | from idlelib.percolator import Percolator | 
|  | undowin = Toplevel(parent) | 
|  | undowin.title("Test UndoDelegator") | 
|  | x, y = map(int, parent.geometry().split('+')[1:]) | 
|  | undowin.geometry("+%d+%d" % (x, y + 175)) | 
|  |  | 
|  | text = Text(undowin, height=10) | 
|  | text.pack() | 
|  | text.focus_set() | 
|  | p = Percolator(text) | 
|  | d = UndoDelegator() | 
|  | p.insertfilter(d) | 
|  |  | 
|  | undo = Button(undowin, text="Undo", command=lambda:d.undo_event(None)) | 
|  | undo.pack(side='left') | 
|  | redo = Button(undowin, text="Redo", command=lambda:d.redo_event(None)) | 
|  | redo.pack(side='left') | 
|  | dump = Button(undowin, text="Dump", command=lambda:d.dump_event(None)) | 
|  | dump.pack(side='left') | 
|  |  | 
|  | if __name__ == "__main__": | 
|  | from unittest import main | 
|  | main('idlelib.idle_test.test_undo', verbosity=2, exit=False) | 
|  |  | 
|  | from idlelib.idle_test.htest import run | 
|  | run(_undo_delegator) |