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
|
/* <copyright>
This file contains proprietary software owned by Motorola Mobility, Inc.<br/>
No rights, expressed or implied, whatsoever to this software are provided by Motorola Mobility, Inc. hereunder.<br/>
(c) Copyright 2011 Motorola Mobility, Inc. All Rights Reserved.
</copyright> */
// Consider proposal at https://rniwa.com/editing/undomanager.html
var Montage = require("montage").Montage;
exports.UndoManager = Montage.create(Montage, {
enabled: {
value: true
},
_maxUndoCount: {
enumerable: false,
value: null
},
maxUndoCount: {
get: function() {
return this._maxUndoCount;
},
set: function(value) {
if (value === this._maxUndoCount) {
return;
}
this._maxUndoCount = value;
if (this._maxUndoCount != null) {
this._trimStacks();
}
}
},
_trimStacks: {
enumerable: false,
value: function() {
var undoRemoveCount = this._maxUndoCount - this.undoStack.length,
redoRemoveCount = this._maxUndoCount - this.redoStack.length;
if (undoRemoveCount > 0) {
this.undoStack.splice(0, undoRemoveCount);
}
if (redoRemoveCount > 0) {
this.redoStack.splice(0, redoRemoveCount);
}
}
},
_undoStack: {
enumerable: false,
value: null
},
undoStack: {
get: function() {
if (!this._undoStack) {
this._undoStack = [];
}
return this._undoStack
}
},
redoStack: {
value: [],
distinct: true
},
add: {
value: function(label, undoFunction, context) {
if (0 === this._maxUndoCount) {
return;
}
var undoEntry = {
label: label,
undoFunction: undoFunction,
context: context,
args: Array.prototype.slice.call(arguments, 3)
};
// seeing as you can only ever add one entry at a time to either stack, we should never need to make room
// for more than a single entry at this point; there's no need for an expensive trim
if (this.isUndoing) {
// preserve the label of the current action being undone to be the name of the redo
undoEntry.label = this.undoEntry.label;
if (this.redoStack.length === this._maxUndoCount) {
this.redoStack.shift();
}
this.redoStack.push(undoEntry);
} else {
if (this.undoStack.length === this._maxUndoCount) {
this.undoStack.shift();
}
this.undoStack.push(undoEntry);
if (!this.isRedoing && this.redoStack.length > 0) {
this.clearRedo();
}
}
}
},
clearUndo: {
value: function() {
this.undoStack.splice(0, this.undoStack.length);
}
},
clearRedo: {
value: function() {
this.redoStack.splice(0, this.redoStack.length);
}
},
isUndoing: {
dependencies: ["undoEntry"],
get: function() {
return !!this.undoEntry;
}
},
isRedoing: {
dependencies: ["redoEntry"],
get: function() {
return !!this.redoEntry;
}
},
undoEntry: {
enumerable: false,
value: null
},
redoEntry: {
enumerable: false,
value: null
},
undo: {
value: function() {
if (this.isUndoing || this.isRedoing) {
throw "UndoManager cannot initiate an undo or redo while undoing.";
}
if (this.undoStack.length === 0) {
return;
}
var entry = this.undoEntry = this.undoStack.pop();
entry.undoFunction.apply(entry.context, entry.args);
this.undoEntry = null;
}
},
redo: {
value: function() {
if (this.isUndoing || this.isRedoing) {
throw "UndoManager cannot initiate an undo or redo while redoing.";
}
if (this.redoStack.length === 0) {
return;
}
var entry = this.redoEntry = this.redoStack.pop();
entry.undoFunction.apply(entry.context, entry.args);
this.redoEntry = null;
}
},
canUndo: {
dependencies: ["undoStack.count()"],
get: function() {
return !!this.undoStack.length;
}
},
canRedo: {
dependencies: ["redoStack.count()"],
get: function() {
return !!this.redoStack.length;
}
},
undoLabel: {
dependencies: ["undoStack.count()"],
get: function() {
var undoCount = this.undoStack.length,
label;
if (undoCount) {
label = this.undoStack[undoCount - 1].label;
}
return label ? "Undo " + label : "Undo";
},
set: function(value) {
var undoCount = this.redoStack.length;
if (undoCount) {
this.undoStack[undoCount - 1].label = value;
}
}
},
redoLabel: {
dependencies: ["redoStack.count()"],
get: function() {
var redoCount = this.redoStack.length,
label;
if (redoCount) {
label = this.redoStack[redoCount - 1].label
}
return label ? "Redo " + label : "Redo";
},
set: function(value) {
var redoCount = this.redoStack.length;
if (redoCount) {
this.redoStack[redoCount - 1].label = value;
}
}
}
});
|