containertiming-observe-after-paint-with-buffering.html (1607B)
1 <!DOCTYPE HTML> 2 <meta charset=utf-8> 3 <title>Container Timing: starting observation after image paint, with buffering, reports paint.</title> 4 <body> 5 <style> 6 body { 7 margin: 0; 8 } 9 </style> 10 <script src="/resources/testharness.js"></script> 11 <script src="/resources/testharnessreport.js"></script> 12 <script src="/container-timing/resources/container-timing-helpers.js"></script> 13 <script src="/element-timing/resources/element-timing-helpers.js"></script> 14 <script> 15 let beforeRender; 16 async_test(function (t) { 17 assert_implements(window.PerformanceContainerTiming, "PerformanceContainerTiming is not implemented"); 18 onElementTimingEvent(() => { 19 const observer = new PerformanceObserver( 20 t.step_func_done((entryList) => { 21 assert_equals(entryList.getEntries().length, 1); 22 const entry = entryList.getEntries()[0]; 23 checkContainerEntry(entry, 'image_ct', 'my_id', beforeRender); 24 checkRect(entry, [0, 100, 0, 100]) 25 checkContainerSize(entry, 10000); 26 }) 27 ); 28 observer.observe({type: 'container', buffered: true }); 29 }); 30 31 // Add image of width equal to 100 and height equal to 100. 32 const img = document.createElement('img'); 33 img.src = '/container-timing/resources/square100.png'; 34 img.setAttribute('containertiming', 'image_ct'); 35 img.setAttribute('id', 'my_id'); 36 document.body.appendChild(img); 37 38 beforeRender = performance.now(); 39 40 addPaintingElementTimingAfterDoubleRAF(document.body); 41 }, 'Paint is reported when observation starts after image paint if buffering is enabled.'); 42 </script> 43 44 </body>