| <!DOCTYPE html> |
| <body> |
| <div id="image"></div> |
| <script> |
| const img = document.createElement('IMG'); |
| img.src = 'circles.png'; |
| |
| var observer = new PerformanceObserver(function(list, obj) { |
| var paintEntries = list.getEntries(); |
| for (let i = 0; i < paintEntries.length; i++) { |
| // postMessage doesn't allow sending the entry object over directly |
| var dataToSend = { |
| "entryType": paintEntries[i]["entryType"], |
| "name": paintEntries[i]["name"] |
| }; |
| parent.postMessage(dataToSend, '*'); |
| } |
| }); |
| |
| observer.observe({"type": "paint"}); |
| document.getElementById('image').appendChild(img); |
| </script> |
| </body> |
| </html> |