;;;;;;;(function(exports){'use strict';var debug=false;function log(str){if(!debug){return;}
console.log('🎶 ',str);}
var naive=false;var naiveExec=function(block){block();return Promise.resolve();};var directProtectionWindow=360;var Scheduler=function(){this._directTracking=new Map();this._ongoingTransitions=0;this._queuedTransitions=[];this._flushing=false;this._pendingMutations=[];};Scheduler.prototype={attachDirect:function(elm,evtType,block){var tracking=this._directTracking;if(!tracking.get(elm)){tracking.set(elm,{});}
var tElm=tracking.get(elm);if(!(evtType in tElm)){tElm[evtType]={rafID:null,protectionTimeout:null,blocks:[]};}
var tEvt=tElm[evtType];if(!tEvt.blocks.length){elm.addEventListener(evtType,this);}
tEvt.blocks.push(block);},detachDirect:function(elm,evtType,block){var tEvt=this._trackingFor(elm,evtType);if(!tEvt){return;}
if(tEvt.rafID){window.cancelAnimationFrame(tEvt.rafID);}
if(tEvt.protectionTimeout){clearTimeout(tEvt.protectionTimeout);tEvt.protectionTimeout=null;this._stopProtectingDirect();}
var toRemove=tEvt.blocks.indexOf(block);if(toRemove===-1){log('wrong detach block');return;}
tEvt.blocks.splice(toRemove,1);if(!tEvt.blocks.length){elm.removeEventListener(evtType,this);var tElm=this._directTracking.get(elm);delete tElm[evtType];if(Object.keys(tElm).length===0){this._directTracking.delete(elm);}}},_trackingFor:function(elm,evtType){var tracking=this._directTracking;if(!tracking.get(elm)){log('wrong detach element');return;}
var tElm=tracking.get(elm);if(!(evtType in tElm)){log('wrong detach event');return;}
return tElm[evtType];},_shouldProtectDirect:function(){var tracking=this._directTracking;for(var elm of tracking.keys()){var tElm=tracking.get(elm);for(var evtType in tElm){var tEvt=tElm[evtType];if(tEvt.protectionTimeout!==null){return true;}}}
return false;},_stopProtectingDirect:function(){this._dequeueTransitions();this._flushMutations();if(debug){console.timeEnd('protecting');}},handleEvent:function(evt){var tEvt=this._trackingFor(evt.currentTarget,evt.type);if(!tEvt){return;}
if(naive){tEvt.blocks.forEach(function(block){block(evt);});return;}
if(tEvt.protectionTimeout){clearTimeout(tEvt.protectionTimeout);}else{if(debug){console.time('protecting');}}
tEvt.protectionTimeout=setTimeout((function(){tEvt.protectionTimeout=null;this._stopProtectingDirect();}).bind(this),directProtectionWindow);if(tEvt.rafID){window.cancelAnimationFrame(tEvt.rafID);}
tEvt.rafID=window.requestAnimationFrame(function(){tEvt.blocks.forEach(function(block){var startDate;if(debug){startDate=performance.now();}
block(evt);if(debug){var blockDuration=performance.now()-startDate;if(blockDuration>16){log('Direct block took more than a frame ('+
blockDuration.toString()+'ms)');}}});});},feedback:function(block,elm,evt,timeout){return this._transition(block,true,elm,evt,timeout);},transition:function(block,elm,evt,timeout){return this._transition(block,false,elm,evt,timeout);},_transition:function(block,feedback,elm,evt,timeout){if(naive){return naiveExec(block);}
timeout=timeout||500;return new Promise((function(resolve,reject){var content=(function(){this._ongoingTransitions++;block();if(!elm||!evt){this._ongoingTransitions--;resolve();return;}
if(debug){console.time('animating');}
var finishTimeout;var done=(function(){clearTimeout(finishTimeout);elm.removeEventListener(evt,done);this._ongoingTransitions--;if(debug){console.timeEnd('animating');}
if(this._ongoingTransitions===0){setTimeout(this._flushMutations.bind(this));}
resolve();}).bind(this);elm.addEventListener(evt,done);finishTimeout=setTimeout(function(){done();log('Transition block saved by a timeout of '+timeout+' ~ '+
elm.style.transition);},timeout);}).bind(this);if(this._flushing||(this._shouldProtectDirect()&&!feedback)){this._queuedTransitions.push(content);}else{content();}}).bind(this));},_dequeueTransitions:function(){if(this._queuedTransitions.length===0){return;}
if(this._flushing||this._shouldProtectDirect()){return;}
var transitions=this._queuedTransitions;transitions.forEach(function(transition){transition();});this._queuedTransitions=[];},mutation:function(block){if(naive){return naiveExec(block);}
return new Promise((function(resolve,reject){if(this._shouldProtectDirect()||this._ongoingTransitions>0){this._pendingMutations.push({block:block,resolve:resolve});}else{Promise.resolve().then(block).then(resolve);}}).bind(this));},_flushMutations:function(){if(this._pendingMutations.length===0){return;}
if(this._shouldProtectDirect()||this._ongoingTransitions>0){return;}
this._flushing=true;var fulfilments=this._pendingMutations.map(function(obj){return obj.resolve;});var mutations=this._pendingMutations;mutations.forEach(function(mutation){mutation.block();});this._pendingMutations=[];this._flushing=false;fulfilments.forEach(function(resolve){resolve();});this._dequeueTransitions();}};exports.DomScheduler=Scheduler;if(!exports.scheduler||typeof exports.scheduler.mutation!=='function')Object.defineProperty(exports,'scheduler',{value:new Scheduler(),configurable:true,writable:true});})(window);