Add a requestAnimationFrame polyfill

Author: rreusser

src/lib/index.js

@@ -13,6 +13,8 @@ var d3 = require('d3');
 
 var lib = module.exports = {};
 
+require('./request_animation_frame');
+
 lib.nestedProperty = require('./nested_property');
 lib.isPlainObject = require('./is_plain_object');
 lib.isArray = require('./is_array');

src/lib/request_animation_frame.js

@@ -0,0 +1,33 @@
+/**
+* Copyright 2012-2016, Plotly, Inc.
+* All rights reserved.
+*
+* This source code is licensed under the MIT license found in the
+* LICENSE file in the root directory of this source tree.
+*/
+
+
+'use strict';
+
+if(!Date.now) {
+    Date.now = function() { return new Date().getTime(); };
+}
+
+var vendors = ['webkit', 'moz'];
+for(var i = 0; i < vendors.length && !window.requestAnimationFrame; ++i) {
+    var vp = vendors[i];
+    window.requestAnimationFrame = window[vp + 'RequestAnimationFrame'];
+    window.cancelAnimationFrame = (window[vp + 'CancelAnimationFrame'] ||
+                                   window[vp + 'CancelRequestAnimationFrame']);
+}
+if(/iP(ad|hone|od).*OS 6/.test(window.navigator.userAgent) || // iOS6 is buggy
+    !window.requestAnimationFrame || !window.cancelAnimationFrame) {
+    var lastTime = 0;
+    window.requestAnimationFrame = function(callback) {
+        var now = Date.now();
+        var nextTime = Math.max(lastTime + 16, now);
+        return setTimeout(function() { callback(lastTime = nextTime); },
+                          nextTime - now);
+    };
+    window.cancelAnimationFrame = clearTimeout;
+}