| <!DOCTYPE HTML> |
| <meta charset=utf-8> |
| <title>Element Timing: observe text</title> |
| <body> |
| <style> |
| body { |
| margin: 20px; |
| } |
| p { |
| font-size: 12px; |
| } |
| </style> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="resources/element-timing-helpers.js"></script> |
| <script> |
| async_test((t) => { |
| if (!window.PerformanceElementTiming) { |
| assert_unreached("PerformanceElementTiming is not implemented"); |
| } |
| let paragraph; |
| let beforeRender; |
| const observer = new PerformanceObserver( |
| t.step_func_done((entryList) => { |
| assert_equals(entryList.getEntries().length, 1); |
| const entry = entryList.getEntries()[0]; |
| checkTextElement(entry, 'my_text', 'text_id', beforeRender, paragraph); |
| assert_equals(entry.intersectionRect.left, 20, 'left should be 20.'); |
| // Text box size will vary from device to device, so try lower bounding height by 12, width by 100. |
| assert_greater_than_equal(entry.intersectionRect.right, 120); |
| |
| assert_equals(entry.intersectionRect.top, 20, 'top should be 20.'); |
| assert_greater_than_equal(entry.intersectionRect.bottom, 32); |
| }) |
| ); |
| observer.observe({entryTypes: ['element']}); |
| // We add the iframe during onload to be sure that the observer is registered |
| // in time for it to observe the element timing. |
| window.onload = () => { |
| paragraph = document.createElement('p'); |
| paragraph.innerHTML = 'This is text I care about'; |
| paragraph.setAttribute('elementtiming', 'my_text'); |
| paragraph.setAttribute('id', 'text_id'); |
| document.body.appendChild(paragraph); |
| beforeRender = performance.now(); |
| }; |
| }, 'Paragraph with elementtiming attribute is observed.'); |
| </script> |
| |
| </body> |
