summaryrefslogtreecommitdiffstats
path: root/Lib/idlelib/undo.py
blob: 85ecffecb4cbcbf98004ca24a38ebe7052f5756f (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
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)