| <!DOCTYPE HTML> |
| <meta charset=utf-8> |
| <title>Element Timing: observe elements with the same resource</title> |
| <body> |
| <style> |
| body { |
| margin: 0; |
| } |
| </style> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="resources/element-timing-helpers.js"></script> |
| <script> |
| let beforeRender; |
| let numEntries = 0; |
| let responseEnd1; |
| let responseEnd2; |
| const index = window.location.href.lastIndexOf('/'); |
| const pathname = window.location.href.substring(0, index) + |
| '/resources/square100.png'; |
| async_test(function (t) { |
| const observer = new PerformanceObserver( |
| t.step_func(function(entryList) { |
| entryList.getEntries().forEach(entry => { |
| checkElement(entry, pathname, entry.identifier, beforeRender); |
| if (entry.identifier === 'my_image') { |
| ++numEntries; |
| responseEnd1 = entry.responseEnd; |
| } |
| else if (entry.identifier === 'my_image2') { |
| ++numEntries; |
| responseEnd2 = entry.responseEnd; |
| } |
| }); |
| if (numEntries == 2) { |
| assert_equals(responseEnd1, responseEnd2); |
| t.done(); |
| } |
| }) |
| ); |
| observer.observe({entryTypes: ['element']}); |
| // We add the images during onload to be sure that the observer is registered |
| // in time for it to observe the element timing. |
| window.onload = () => { |
| // Add image of width and height equal to 100. |
| const img = document.createElement('img'); |
| img.src = 'resources/square100.png'; |
| img.setAttribute('elementtiming', 'my_image'); |
| document.body.appendChild(img); |
| |
| const img2 = document.createElement('img'); |
| img2.src = 'resources/square100.png'; |
| img2.setAttribute('elementtiming', 'my_image2'); |
| document.body.appendChild(img2); |
| |
| beforeRender = performance.now(); |
| }; |
| }, 'Element with elementtiming attribute is observable.'); |
| </script> |
| |
| </body> |
