overscroll/es/utils/requestAnimationFrame.js

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import is from 'whatitis';
import invariant from 'invariant';
import now from 'performance-now';

var root = typeof window === 'undefined' ? global : window;
var vendors = ['moz', 'webkit'];
var suffix = 'AnimationFrame';
var raf = root['request' + suffix];
var caf = root['cancel' + suffix] || root['cancelRequest' + suffix];

for (var i = 0; !raf && i < vendors.length; i++) {
  var prefix = vendors[i];
  raf = root[prefix + 'Request' + suffix];
  caf = root[prefix + 'Cancel' + suffix] || root[prefix + 'CancelRequest' + suffix];
}

// Some versions of FF have rAF but not cAF
if (!raf || !caf) {

  var chain = void 0;
  var id = 0;
  var lastTime = 0;
  var handles = {};
  var frameDuration = 1000 / 60;
  var throwError = function throwError(err) {
    return function () {
      throw err;
    };
  };
  var compose = function compose(callback1, callback2) {
    return function (lastTime) {
      return callback1(callback2(lastTime));
    };
  };
  var handler = function handler(handle, next) {
    return function (lastTime) {
      if (handles[handle] !== false) {
        next(lastTime);
      } else {
        handles[handle] = null;
      }
      return lastTime;
    };
  };
  var next = function next(handled) {
    chain = chain ? compose(handled, chain) : handled;
  };
  var toCall = function toCall() {
    var cp = chain;
    // Clear chain here to prevent
    // callbacks from appending listeners
    // to the current frame's chain
    chain = null;
    try {
      cp(lastTime);
    } catch (e) {
      setTimeout(throwError(e), 0);
    }
  };

  raf = function raf(callback) {
    if (!chain) {
      var currTime = now();
      var timeToCall = Math.max(0, frameDuration - (currTime - lastTime));
      lastTime = timeToCall + currTime;
      root.setTimeout(toCall, Math.round(timeToCall));
    }
    next(handler(++id, callback));
    return id;
  };

  caf = function caf(arg) {
    handles[arg] = false;
  };
}

export default function polyfill() {
  root.requestAnimationFrame = raf;
  root.cancelAnimationFrame = caf;
  return {
    requestAnimationFrame: root.requestAnimationFrame,
    cancelAnimationFrame: root.cancelAnimationFrame
  };
}

var _polyfill = polyfill(),
    requestAnimationFrame = _polyfill.requestAnimationFrame,
    cancelAnimationFrame = _polyfill.cancelAnimationFrame;

export function requestAnimFrame(callback) {

  invariant(is.Function(callback), 'Expecting callback of requestAnimFrame is a function.');

  var id = void 0;
  var getFrameHandler = function getFrameHandler() {
    return id;
  };
  var cancel = function cancel() {
    return cancelAnimationFrame(id);
  };
  id = requestAnimationFrame(function frameCallback(time) {
    callback(Math.round(time * 10) / 10, cancel);
    id = requestAnimationFrame(frameCallback);
  });

  return { cancel: cancel, getFrameHandler: getFrameHandler };
}