fcp-opacity.html (1021B)
1 <!DOCTYPE html> 2 <head> 3 <title>Performance Paint Timing Test: FCP due to opacity</title> 4 <style> 5 #main { 6 width: 100px; 7 height: 100px; 8 left: 0px; 9 position: relative; 10 top: 0; 11 background-image: url(../resources/circles.png); 12 opacity: 0; 13 } 14 15 /* contentful class is defined in test_fcp script. */ 16 #main.contentful { 17 opacity: 0.1; 18 } 19 </style> 20 </head> 21 <body> 22 <script src="/resources/testharness.js"></script> 23 <script src="/resources/testharnessreport.js"></script> 24 <script src="../resources/utils.js"></script> 25 <div id="main"></div> 26 <script> 27 // Load the image into memory first to make sure it's decoded. 28 function load_image() { 29 const img = document.createElement("img"); 30 img.src = "../resources/circles.png"; 31 32 return new Promise(resolve => { 33 img.onload = async () => resolve(); 34 }); 35 } 36 37 test_fcp("First contentful paint fires due to opacity-revealed element.", load_image); 38 </script> 39 </body> 40 </html>