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
|
# UndoManager.py
# This file is part of Labyrinth
#
# Copyright (C) 2006 - Don Scorgie <Don@Scorgie.org>
#
# Labyrinth is free software; you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation; either version 2 of the License, or
# (at your option) any later version.
#
# Labyrinth is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Labyrinth; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor,
# Boston, MA 02110-1301 USA
#
import gtk
# Different modes of operation - redo, undo
UNDO = 0
REDO = 1
# Some general actions we should always expect.
# Some require special handling within ourselves
# (taking care of letter insertion / word insertion)
INSERT_LETTER = 100
INSERT_WORD = 101
DELETE_LETTER = 102
DELETE_WORD = 103
TRANSFORM_CANVAS = 104
class UndoAction:
def __init__(self, owner, undo_type, callback, *args):
self.owner = owner
self.undo_type = undo_type
self.callback = callback
self.text = ""
if undo_type == INSERT_LETTER or undo_type == INSERT_WORD or undo_type == DELETE_LETTER or \
undo_type == DELETE_WORD:
for z in args:
if isinstance(z, basestring):
self.text = z
break
self.args = args
def add_arg (self, *args):
for t in args:
self.args += (t,)
class UndoManager:
''' A basic manager for undoing and redoing actions.\
Doesn't do anything itself, instead it marshals \
all the minion classes to do its bidding. Any class \
can add items to its lists and they're corresponding \
methods will be called if and when needed. The \
manager doesn't care what you give it, so long as
it has a method to call and an owner'''
def __init__(self, top_owner, undo_widget = None, redo_widget = None):
self.undo = undo_widget
self.redo = redo_widget
self.blocked = False
self.undo_list = []
self.redo_list = []
if self.undo:
self.undo.connect('activate', self.undo_action)
if self.redo:
self.redo.connect('activate', self.redo_action)
self.owner = top_owner
self.update_sensitive ()
def block (self):
''' Used as generally, when an undo is performed a \
signal will be emitted that causes an undo action \
to be added. Use this to block tht from happening \
To add actions again, call unblock'''
self.blocked = True
def unblock (self):
self.blocked = False
def set_widgets (self, undo, redo):
self.undo = undo
self.redo = redo
self.undo.connect('activate', self.undo_action)
self.redo.connect('activate', self.redo_action)
self.update_sensitive ()
def update_sensitive (self):
if not self.undo or not self.redo:
return
self.undo.set_sensitive(len(self.undo_list) > 0)
self.redo.set_sensitive(len(self.redo_list) > 0)
def undo_action (self, arg):
result = self.undo_list.pop()
self.redo_list.append (result)
self.update_sensitive ()
result.callback (result, mode=UNDO)
def forget_action (self):
result = self.undo_list.pop()
self.update_sensitive ()
result.callback (result, mode=UNDO)
def redo_action (self, arg):
result = self.redo_list.pop()
self.undo_list.append (result)
self.update_sensitive ()
result.callback (result, mode=REDO)
def combine_insertions (self, action):
final_text = action.text
start_iter = action.args[0]
length = action.args[2]
owner = action.owner
cb = action.callback
old_attrs = action.args[3]
new_attrs = action.args[4]
if len (self.undo_list) > 0:
back = self.undo_list.pop ()
else:
self.undo_list.append (action)
return
add_back = True
while back and back.owner == owner \
and (back.undo_type == INSERT_LETTER or back.undo_type == INSERT_WORD):
if back.text.rfind(' ') != -1:
break
old_attrs = back.args[3]
if back.args[0] <= start_iter:
start_iter = back.args[0]
final_text = back.text+final_text
else:
final_text += back.text
length += back.args[2]
if len (self.undo_list) == 0:
add_back = False
break
back = self.undo_list.pop ()
if add_back:
self.undo_list.append (back)
combi = UndoAction (owner, INSERT_WORD, cb, start_iter, final_text, length, old_attrs, new_attrs)
self.undo_list.append (combi)
def combine_deletions (self, action):
bytes = True
byte_collection = action.args[3]
final_text = action.text
start_iter = action.args[0]
length = action.args[2]
owner = action.owner
cb = action.callback
old_attrs = action.args[4]
new_attrs = action.args[5]
if len (self.undo_list) > 0:
back = self.undo_list.pop ()
else:
self.undo_list.append (action)
return
add_back = True
while back and back.owner == owner \
and (back.undo_type == DELETE_LETTER or back.undo_type == DELETE_WORD):
if back.text.rfind(' ') != -1:
break
old_attrs = back.args[4]
if back.args[0] <= start_iter:
start_iter = back.args[0]
final_text = back.text+final_text
if bytes:
byte_collection = back.args[3] + byte_collection
else:
final_text += back.text
if bytes:
byte_collection += back.args[3]
length += back.args[2]
if len (self.undo_list) == 0:
add_back = False
break
back = self.undo_list.pop ()
if add_back:
self.undo_list.append (back)
if bytes:
combi = UndoAction (owner, DELETE_WORD, cb, start_iter, final_text, length, byte_collection, old_attrs, new_attrs)
else:
combi = UndoAction (owner, DELETE_WORD, cb, start_iter, final_text, length, -1, old_attrs, new_attrs)
self.undo_list.append (combi)
def combine_transforms (self, action):
if len (self.undo_list) > 0:
back = self.undo_list.pop ()
else:
self.undo_list.append (action)
return
add_back = True
final_zoom = action.args[1]
final_trans = action.args[3]
orig_zoom = action.args[0]
orig_trans = action.args[2]
owner = action.owner
cb = action.callback
while back and back.owner == owner and \
back.undo_type == TRANSFORM_CANVAS:
orig_zoom = back.args[0]
orig_trans = back.args[2]
if len (self.undo_list) == 0:
add_back = False
break
back = self.undo_list.pop ()
if add_back:
self.undo_list.append (back)
self.undo_list.append (UndoAction (owner, TRANSFORM_CANVAS, cb, orig_zoom,
final_zoom, orig_trans, final_trans))
def peak (self):
if len (self.undo_list) > 0:
return self.undo_list[-1]
else:
return UndoAction (None, None, None)
def pop (self):
if len (self.undo_list) > 0:
return self.undo_list.pop ()
else:
return None
def exists_undo_action (self):
return len(self.undo_list) > 0
def exists_redo_action (self):
return len(self.redo_list) > 0
def add_undo (self, action):
if self.blocked:
return
if not isinstance(action, UndoAction):
print "Error: Not a valid undo action. Ignoring."
return
del self.redo_list[:]
if action.undo_type == INSERT_LETTER:
self.combine_insertions (action)
elif action.undo_type == DELETE_LETTER:
self.combine_deletions (action)
elif action.undo_type == TRANSFORM_CANVAS:
self.combine_transforms (action)
else:
self.undo_list.append (action)
self.update_sensitive ()
|
