https://infengi.ru/js/undone.js

1/*!
2 * undone.js 0.0.1 - https://github.com/yckart/undone.js
3 * The undo/redo manager for well formed javascript applications.
4 *
5 * Inspired by: http://blog.asgaard.co.uk/2012/11/21/undo-redo-in-javascript
6 *
7 * Copyright (c) 2012 Yannick Albert (http://yckart.com)
8 * Licensed under the MIT license (http://www.opensource.org/licenses/mit-license.php).
9 * 2013/03/16
10 **/
11;(function(window){
12
13    /**
14      * @constructor
15      */
16    var Undone = function(options) {
17
18        // define the defaults
19        this.options = {
20            buffer: 1000
21        };
22
23        // extend the defaults
24        for(var i in options) this.options[i] = options[i];
25
26        this.history = {
27            undo: [],
28            redo: []
29        };
30    };
31
32    /**
33      * Executes an action and adds it to the undo stack.
34      * @param {Function} action - Action function.
35      * @param {Function} reverse - Reverse function.
36      * @param {Object} ctx - The 'this' argument for the action/reverse functions.
37      */
38    Undone.prototype.register = function(action, reverse, ctx) {
39        if(this.history.undo.length >= this.options.buffer) this.history.undo.unshift();
40        this.history.undo.push( {action: action, reverse: reverse, ctx: ctx} );
41        action.call(ctx);
42        this.history.redo.length = 0;
43        this.change("register", this.history.undo.length, this.history.redo.length);
44    };
45
46    Undone.prototype.undo = function(n) {
47        var len = this.history.undo.length;
48
49        n = n || 1;
50        if(n > len) n = len;
51        if(len < this.options.buffer) {
52            while(n--) {
53                var c = this.history.undo.pop();
54                if (!c) return;
55
56                c.reverse.call(c.ctx);
57                this.history.redo.push(c);
58            }
59            if( len !== this.history.undo.length ) this.change("undo", this.history.undo.length, this.history.redo.length);
60        }
61    };
62
63    Undone.prototype.redo = function(n) {
64
65        var len = this.history.redo.length;
66
67        n = n || 1;
68        if(n > len) n = len;
69        if(len < this.options.buffer) {
70            while(n--) {
71                var c = this.history.redo.pop();
72                if (!c) return;
73                c.action.call(c.ctx);
74                this.history.undo.push(c);
75            }
76            if( len !== this.history.redo.length ) this.change("redo", this.history.undo.length, this.history.redo.length);
77        }
78    };
79
80    Undone.prototype.onChange = function(){};
81    Undone.prototype.change = function(event, undoLen, redoLen){
82        if (this.onChange) this.onChange(event, undoLen, redoLen);
83        if(window.jQuery) $(window).trigger("undone:change", [event, undoLen, redoLen]);
84    };
85
86    Undone.prototype.clear = function(){
87        this.history = {
88            undo: [],
89            redo: []
90        };
91        this.change("clear", 0, 0);
92    };
93
94    window.Undone = Undone;
95}(window));