| // Copyright 2016 Google Inc. All rights reserved. |
| // |
| // Licensed under the Apache License, Version 2.0 (the "License"); |
| // you may not use this file except in compliance with the License. |
| // You may obtain a copy of the License at |
| // |
| // http://www.apache.org/licenses/LICENSE-2.0 |
| // |
| // Unless required by applicable law or agreed to in writing, software |
| // distributed under the License is distributed on an "AS IS" BASIS, |
| // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. |
| // See the License for the specific language governing permissions and |
| // limitations under the License. |
| |
| (function(shared) { |
| // If the polyfill is being loaded in a context where Element.animate is |
| // supported but object-form syntax is not, then creating an animation |
| // using the new syntax will either have no effect or will throw an exception. |
| // In either case, we want to proceed to load this part of the polyfill. |
| // |
| // The test animation uses an opacity other than the one the element already |
| // has, and doesn't need to change during the animation for the test to work. |
| // After the test, the element's opacity will be left how we found it: |
| // - If the animation is not created, the test will leave the element's |
| // opacity untouched at originalOpacity. |
| // - If the animation is created, it will be cancelled, and leave the |
| // element's opacity at originalOpacity. |
| // - If the animation is somehow created and runs without being cancelled, |
| // when it finishes after 1ms, it will cease to have any effect (because |
| // fill is not specified), and opacity will again be left at originalOpacity. |
| var element = document.documentElement; |
| var animation = null; |
| var animated = false; |
| try { |
| var originalOpacity = getComputedStyle(element).getPropertyValue('opacity'); |
| var testOpacity = originalOpacity == '0' ? '1' : '0'; |
| animation = element.animate({'opacity': [testOpacity, testOpacity]}, |
| {duration: 1}); |
| animation.currentTime = 0; |
| animated = getComputedStyle(element).getPropertyValue('opacity') == testOpacity; |
| } catch (error) { |
| } finally { |
| if (animation) |
| animation.cancel(); |
| } |
| if (animated) { |
| return; |
| } |
| |
| var originalElementAnimate = window.Element.prototype.animate; |
| window.Element.prototype.animate = function(effectInput, options) { |
| if (window.Symbol && Symbol.iterator && Array.prototype.from && effectInput[Symbol.iterator]) { |
| // Handle custom iterables in most browsers by converting to an array |
| effectInput = Array.from(effectInput); |
| } |
| |
| if (!Array.isArray(effectInput) && effectInput !== null) { |
| effectInput = shared.convertToArrayForm(effectInput); |
| } |
| |
| return originalElementAnimate.call(this, effectInput, options); |
| }; |
| })(webAnimationsShared); |