testing/web-platform/tests/element-timing/observe-video-poster.html

   1 <!DOCTYPE HTML>
   2 <meta charset=utf-8>
   3 <title>Element Timing: observe video poster image</title>
   4 <script src="/resources/testharness.js"></script>
   5 <script src="/resources/testharnessreport.js"></script>
   6 <script src="resources/element-timing-helpers.js"></script>
   7 <script>
   8 let beforeRender;
   9 async_test(function (t) {
  10   assert_precondition(window.PerformanceElementTiming, "PerformanceElementTiming is not implemented");
  11   const observer = new PerformanceObserver(
  12     t.step_func_done(function(entryList) {
  13       assert_equals(entryList.getEntries().length, 1);
  14       const entry = entryList.getEntries()[0];
  15       const pathname = window.location.origin + '/element-timing/resources/circle.svg';
  16       checkElement(entry, pathname, 'my_poster', 'the_poster', beforeRender,
  17           document.getElementById('the_poster'));
  18       // Assume viewport has size at least 200, so the element is fully visible.
  19       checkRect(entry, [0, 200, 0, 200]);
  20       checkNaturalSize(entry, 200, 200);
  21     })
  22   );
  23   observer.observe({entryTypes: ['element']});
  24   beforeRender = performance.now();
  25 }, "Able to observe a video's poster image.");
  26 </script>
  27 <style>
  28 body {
  29   margin: 0;
  30 }
  31 </style>
  32 <video elementtiming='my_poster' id='the_poster' src='/media/test.mp4' poster='resources/circle.svg'/>