1 <!-- 2 Copyright 2014 The Chromium Authors. All rights reserved. 3 Use of this source code is governed by a BSD-style license that can be 4 found in the LICENSE file. 5 --> 6 7 <script> 8 // Schedule a repeated action with requestAnimationFrame to avoid doing work 9 // when the tab is hidden. 10 function CTScheduledUpdater(callback, interval) { 11 this.callback = callback; 12 this._isScheduled = false; 13 this._intervalId = setInterval(this._schedule.bind(this), interval); 14 } 15 16 CTScheduledUpdater.prototype._schedule = function() { 17 if (this._isScheduled) 18 return; 19 20 this._isScheduled = true; 21 requestAnimationFrame(this._do.bind(this)); 22 } 23 24 CTScheduledUpdater.prototype._do = function() { 25 this._isScheduled = false; 26 this.callback(); 27 } 28 </script> 29
