!function(a){function b(a){function b(b,c){a.handler(function(a,d){d.sketch.clear(),d.sketch.context.drawImage(b,0,0),d.strokes=c.slice()})}function c(a){if(a.ctrlKey)switch(a.which){case 26:a.shiftKey?f.redo():f.undo();break;case 25:f.redo()}}var d=[],e=-1,f=this;this.undo=function(){return e>0&&(e--,this.restore()),this},this.redo=function(){return e<d.length-1&&(e++,this.restore()),this},this.reset=function(){return d=[],e=-1,this.save()},this.save=function(b){return a.handler(function(a,c){b&&b.identifier>0?d[e].strokes=c.strokes.slice():(d.push({image:a.toDataURL(),strokes:c.strokes.slice()}),e++)}),this},this.state=function(){return JSON.parse(JSON.stringify(d[e]))},this.restore=function(a){a||(a=d[e]);var c=new Image;return c.src=a.image,c.onload=function(){b(this,a.strokes)},this},this.init=function(){return Event.remove(document,"keypress",c),Event.add(document,"keypress",c),this.save()},this.destroy=function(){return Event.remove(document,"keypress",c),this.reset()}}var c="sketchable";Sketchable.prototype.plugins.memento=function(a){function d(b){if(!e.options["_bound.memento$"+b])if(e.options["_bound.memento$"+b]=!0,e.options.events&&"function"==typeof e.options.events[b]){var c=e.options.events[b];e.options.events[b]=function(){c.apply(a,arguments),f[b].apply(a,arguments)}}else e.options.events[b]=f[b]}for(var e=a.config(),f={clear:function(a,b){b.memento.reset()},mouseup:function(a,b,c){b.memento.save(c)},destroy:function(a,b){b.memento.destroy()}},g="mouseup clear destroy".split(" "),h=0;h<g.length;h++)d(g[h]);deepExtend(a,{memento:{undo:function(){var b=dataBind(a.elem)[c];return b.memento.undo(),a},redo:function(){var b=dataBind(a.elem)[c];return b.memento.redo(),a},save:function(){var b=dataBind(a.elem)[c];return b.memento.save(),a},state:function(){var b=dataBind(a.elem)[c];return b.memento.state()},restore:function(b){var d=dataBind(a.elem)[c];return d.memento.restore(b),a}}}),e.memento=new b(a),e.memento.init()}}(this);