text-with-display-style.html (1966B)
1 <!DOCTYPE HTML> 2 <meta charset=utf-8> 3 <title>Element Timing: observe text with display style.</title> 4 <body> 5 <script src="/resources/testharness.js"></script> 6 <script src="/resources/testharnessreport.js"></script> 7 <script src="resources/element-timing-helpers.js"></script> 8 <style> 9 h1 { 10 display: flex; 11 } 12 h2 { 13 display: grid; 14 } 15 h3 { 16 display: block; 17 } 18 </style> 19 <h1 id='title1' elementtiming='h1'>I am h1</h1> 20 <h2 id='title2' elementtiming='h2'>I am h2</h2> 21 <h3 id='title3' elementtiming='h3'>I am h3</h3> 22 <script> 23 async_test(function (t) { 24 assert_implements(window.PerformanceElementTiming, "PerformanceElementTiming is not implemented"); 25 const beforeRender = performance.now(); 26 let observedFlex = false; 27 let observedGrid = false; 28 let observedBlock = false; 29 const observer = new PerformanceObserver( 30 t.step_func(function(entryList) { 31 entryList.getEntries().forEach(entry => { 32 if (entry.id === 'title1') { 33 assert_false(observedFlex, 'Should observe flex once'); 34 observedFlex = true; 35 checkTextElement(entry, 'h1', 'title1', beforeRender, document.getElementById('title1')); 36 } else if (entry.id === 'title2') { 37 assert_false(observedGrid, 'Should observe grid once'); 38 observedGrid = true; 39 checkTextElement(entry, 'h2', 'title2', beforeRender, document.getElementById('title2')); 40 } else { 41 assert_equals(entry.id, 'title3', 'ID should be title1, title2, or title3'); 42 assert_false(observedBlock, 'Should observe block once'); 43 observedBlock = true; 44 checkTextElement(entry, 'h3', 'title3', beforeRender, document.getElementById('title3')); 45 } 46 }); 47 if (observedFlex && observedGrid && observedBlock) 48 t.done(); 49 }) 50 ); 51 observer.observe({type: 'element', buffered: true}); 52 }, 'Text with display style is observable.'); 53 </script> 54 </body>