fcp-bg-image-two-steps.html (1102B)
1 <!DOCTYPE html> 2 <head> 3 <title>Performance Paint Timing Test: FCP should fire for background image only when visible</title> 4 <style> 5 #main { 6 width: 100px; 7 height: 100px; 8 } 9 10 /* contentful and preFCP classes are defined in test_fcp script. */ 11 #main.preFCP { 12 visibility: hidden; 13 } 14 15 #main.contentful, #main.preFCP { 16 background-image: url(../resources/circles.png); 17 } 18 19 #main.contentful { 20 visibility: visible; 21 } 22 </style> 23 </head> 24 <body> 25 <script src="/resources/testharness.js"></script> 26 <script src="/resources/testharnessreport.js"></script> 27 <script src="../resources/utils.js"></script> 28 <div id="main"></div> 29 <script> 30 // Load the image into memory first to make sure it's decoded. 31 function load_image() { 32 const img = document.createElement("img"); 33 img.src = "../resources/circles.png"; 34 35 return new Promise(resolve => { 36 img.onload = async () => resolve(); 37 }); 38 } 39 40 test_fcp("First contentful paint fires for background image only when visible.", load_image); 41 </script> 42 </body> 43 44 </html>