| <!DOCTYPE HTML> |
| <meta charset=utf-8> |
| <title>Element Timing: src change triggers new entry</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> |
| <img elementtiming='my_image' id='my_id' /> |
| <script> |
| const getObservedEntry = async (pathname) => { |
| return await new Promise(resolve => { |
| new PerformanceObserver(entryList => { |
| if (entryList.getEntries()[0].url == pathname) { |
| resolve(entryList.getEntries()[0]); |
| } |
| }).observe({ type: 'element', buffered: true }); |
| }); |
| } |
| |
| promise_test(async (t) => { |
| assert_implements(window.PerformanceElementTiming, "PerformanceElementTiming is not implemented"); |
| |
| // Take beforeRender timestamp. |
| let beforeRender = performance.now(); |
| |
| //Load image |
| const img = document.getElementById('my_id'); |
| |
| const url1 = 'resources/square100.png'; |
| await new Promise(resolve => { |
| img.addEventListener('load', resolve); |
| img.src = url1; |
| }); |
| |
| // Get element entry. |
| let pathname = window.location.origin + '/element-timing/' + url1; |
| let entry = await getObservedEntry(pathname); |
| |
| // Check entry. |
| checkElement(entry, pathname, 'my_image', 'my_id', beforeRender, img); |
| checkRect(entry, [0, 100, 0, 100]); |
| checkNaturalSize(entry, 100, 100); |
| |
| // Take beforeRender timestamp before changing image src. |
| beforeRender = performance.now(); |
| |
| // Set the src to trigger another entry. |
| const url2 = '/images/black-rectangle.png'; |
| |
| //Load image with changed src. |
| await new Promise(resolve => { |
| img.addEventListener('load', resolve); |
| img.src = url2; |
| }); |
| |
| // Get the corresponding element entry. |
| pathname = window.location.origin + url2; |
| entry = await getObservedEntry(pathname); |
| |
| // Check entry. |
| checkElement(entry, pathname, 'my_image', 'my_id', beforeRender, img); |
| checkRect(entry, [0, 100, 0, 50]); |
| checkNaturalSize(entry, 100, 50); |
| }, 'Element Timing: changing src causes a new entry to be dispatched.') |
| </script> |
| |
| </body> |
