1
// Copyright 2008 The Closure Library Authors. All Rights Reserved.
2
//
3
// Licensed under the Apache License, Version 2.0 (the "License");
4
// you may not use this file except in compliance with the License.
5
// You may obtain a copy of the License at
6
//
7
//      http://www.apache.org/licenses/LICENSE-2.0
8
//
9
// Unless required by applicable law or agreed to in writing, software
10
// distributed under the License is distributed on an "AS-IS" BASIS,
11
// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
12
// See the License for the specific language governing permissions and
13
// limitations under the License.
14

15
/**
16
 * @fileoverview Code for an UndoRedoState interface representing an undo and
17
 * redo action for a particular state change. To be used by
18
 * {@link goog.editor.plugins.UndoRedoManager}.
19
 *
20
 */
21

22

23
goog.provide('goog.editor.plugins.UndoRedoState');
24

25
goog.require('goog.events.EventTarget');
26

27

28

29
/**
30
 * Represents an undo and redo action for a particular state transition.
31
 *
32
 * @param {boolean} asynchronous Whether the undo or redo actions for this
33
 *     state complete asynchronously. If true, then this state must fire
34
 *     an ACTION_COMPLETED event when undo or redo is complete.
35
 * @constructor
36
 * @extends {goog.events.EventTarget}
37
 */
38
goog.editor.plugins.UndoRedoState = function(asynchronous) {
39
  goog.editor.plugins.UndoRedoState.base(this, 'constructor');
40

41
  /**
42
   * Indicates if the undo or redo actions for this state complete
43
   * asynchronously.
44
   * @type {boolean}
45
   * @private
46
   */
47
  this.asynchronous_ = asynchronous;
48
};
49
goog.inherits(goog.editor.plugins.UndoRedoState, goog.events.EventTarget);
50

51

52
/**
53
 * Event type for events indicating that this state has completed an undo or
54
 * redo operation.
55
 */
56
goog.editor.plugins.UndoRedoState.ACTION_COMPLETED = 'action_completed';
57

58

59
/**
60
 * @return {boolean} Whether or not the undo and redo actions of this state
61
 *     complete asynchronously. If true, the state will fire an ACTION_COMPLETED
62
 *     event when an undo or redo action is complete.
63
 */
64
goog.editor.plugins.UndoRedoState.prototype.isAsynchronous = function() {
65
  return this.asynchronous_;
66
};
67

68

69
/**
70
 * Undoes the action represented by this state.
71
 */
72
goog.editor.plugins.UndoRedoState.prototype.undo = goog.abstractMethod;
73

74

75
/**
76
 * Redoes the action represented by this state.
77
 */
78
goog.editor.plugins.UndoRedoState.prototype.redo = goog.abstractMethod;
79

80

81
/**
82
 * Checks if two undo-redo states are the same.
83
 * @param {goog.editor.plugins.UndoRedoState} state The state to compare.
84
 * @return {boolean} Wether the two states are equal.
85
 */
86
goog.editor.plugins.UndoRedoState.prototype.equals = goog.abstractMethod;
87

88