/*
* CommandZ v0.1.2
* https://github.com/EtienneLem/commandz
*
* Copyright 2013, Etienne Lemay http://heliom.ca
* Released under the MIT license
*
* Date: 2013-09-27 15:56:22 -0400
*/
(function(){var t,e=function(t,e){return function(){return t.apply(e,arguments)}};t=function(){function t(){this.handleKeypress=e(this.handleKeypress,this),this.VERSION="0.1.2",this.reset(),this.keyboardShortcuts(!0)}return t.prototype.reset=function(){return this.clear(),this.statusChangeCallback=null,this.storageChangeCallback=null,this.thresholdTimer=null,this.threshold=0},t.prototype.clear=function(){return this.history=[],this.index=-1},t.prototype.keyboardShortcuts=function(t){var e;return null==t&&(t=!0),e=t?"addEventListener":"removeEventListener",document[e]("keydown",this.handleKeypress)},t.prototype.handleKeypress=function(t){return"INPUT"!==document.activeElement.nodeName&&(90===t.which&&t.metaKey===!0||26===t.which&&t.ctrlKey===!0)?(t.preventDefault(),t.shiftKey?this.redo():this.undo()):void 0},t.prototype.execute=function(t){var e;return e={},e.command=t,this.up(t),this.addToHistory(e)},t.prototype.store=function(t){var e;return e={},e.data=t,this.addToHistory(e)},t.prototype.addToHistory=function(t){var e;return this.index<this.history.length-1&&(e=this.history.length-this.index-1,this.history.splice(-e)),this.history.push(t),this.index=this.history.length-1,this.handleStatusChange()},t.prototype.undo=function(t){var e,n,s,i,h;if(null==t&&(t=1),this.status().canUndo)for(i=h=1;t>=1?t>=h:h>=t;i=t>=1?++h:--h){if(!this.history[this.index])return;s=this.history[this.index],(e=s.command)&&this.down(e),this.index--,(s=this.history[this.index])&&(n=s.data)&&this.handleData(n),this.handleStatusChange()}},t.prototype.redo=function(t){var e,n,s,i,h;if(null==t&&(t=1),this.status().canRedo)for(i=h=1;t>=1?t>=h:h>=t;i=t>=1?++h:--h){if(!this.history[this.index+1])return;this.index++,s=this.history[this.index],(e=s.command)&&this.up(e),(n=s.data)&&this.handleData(n),this.handleStatusChange()}},t.prototype.exec=function(t,e){var n,s,i,h;if(!(e instanceof Array))return e[t]();for(h=[],s=0,i=e.length;i>s;s++)n=e[s],h.push(n[t]());return h},t.prototype.up=function(t){return this.exec("up",t)},t.prototype.down=function(t){return this.exec("down",t)},t.prototype.handleData=function(t){var e=this;return this.threshold>0?(clearTimeout(this.thresholdTimer),this.thresholdTimer=setTimeout(function(){return e.sendData(t)},this.threshold)):this.sendData(t)},t.prototype.sendData=function(t){return this.storageChangeCallback?this.storageChangeCallback(t):void 0},t.prototype.onStorageChange=function(t){return this.storageChangeCallback=t},t.prototype.setThreshold=function(t){return this.threshold=t},t.prototype.onStatusChange=function(t){return this.statusChangeCallback=t,this.handleStatusChange()},t.prototype.handleStatusChange=function(){return this.statusChangeCallback?this.statusChangeCallback(this.status()):void 0},t.prototype.status=function(){return{canUndo:this.index>-1,canRedo:this.index<this.history.length-1}},t}(),this.CommandZ=new t}).call(this);