| <!DOCTYPE html> |
| <meta name="viewport" content="width=device-width,initial-scale=1"> |
| <script src="/resources/testharness.js"></script> |
| <script src="/resources/testharnessreport.js"></script> |
| <script src="./resources/intersection-observer-test-utils.js"></script> |
| |
| <style> |
| pre, #log { |
| position: absolute; |
| top: 0; |
| left: 200px; |
| } |
| .spacer { |
| height: calc(100vh + 100px); |
| } |
| |
| </style> |
| <div id="leading-space" class="spacer"></div> |
| <div id="trailing-space" class="spacer"></div> |
| |
| <script> |
| // Pick this number to be comfortably greater than the length of two frames at 60Hz. |
| var timeSkew = 40; |
| |
| var topWindowEntries = []; |
| var iframeWindowEntries = []; |
| var targetIframe; |
| var topWindowTimeBeforeNotification; |
| var iframeWindowTimeBeforeNotification; |
| |
| async_test(function(t) { |
| t.step_timeout(function() { |
| targetIframe = document.createElement("iframe"); |
| assert_true(!!targetIframe, "iframe exists"); |
| targetIframe.src = "resources/timestamp-subframe.html"; |
| var trailingSpace = document.getElementById("trailing-space"); |
| assert_true(!!trailingSpace, "trailing-space exists"); |
| trailingSpace.parentNode.insertBefore(targetIframe, trailingSpace); |
| targetIframe.onload = function() { |
| var target = targetIframe.contentDocument.getElementById("target"); |
| var iframeScroller = targetIframe.contentDocument.scrollingElement; |
| |
| // Observer created here, callback created in iframe context. Timestamps should be |
| // from this window. |
| var observer = new IntersectionObserver( |
| targetIframe.contentDocument.createObserverCallback(topWindowEntries), {}); |
| assert_true(!!observer, "Observer exists"); |
| observer.observe(target); |
| |
| // Callback created here, observer created in iframe. Timestamps should be |
| // from iframe window. |
| observer = targetIframe.contentDocument.createObserver(function(newEntries) { |
| iframeWindowEntries = iframeWindowEntries.concat(newEntries); |
| }); |
| observer.observe(target); |
| runTestCycle(step1, "First rAF after iframe is loaded."); |
| t.done(); |
| }; |
| }, timeSkew); |
| }, "Check that timestamps correspond to the to execution context that created the observer."); |
| |
| function step1() { |
| document.scrollingElement.scrollTop = 200; |
| targetIframe.contentDocument.scrollingElement.scrollTop = 250; |
| topWindowTimeBeforeNotification = performance.now(); |
| iframeWindowTimeBeforeNotification = targetIframe.contentWindow.performance.now(); |
| runTestCycle(step2, "Generate notifications."); |
| assert_equals(topWindowEntries.length, 1, "One notification to top window observer."); |
| assert_equals(iframeWindowEntries.length, 1, "One notification to iframe observer."); |
| } |
| |
| function step2() { |
| document.scrollingElement.scrollTop = 0; |
| var topWindowTimeAfterNotification = performance.now(); |
| var iframeWindowTimeAfterNotification = targetIframe.contentWindow.performance.now(); |
| |
| assert_approx_equals( |
| topWindowEntries[1].time - topWindowTimeBeforeNotification, |
| iframeWindowEntries[1].time - iframeWindowTimeBeforeNotification, |
| // Since all intersections are computed in a tight loop between 2 frames, |
| // an epsilon of 16ms (the length of one frame at 60Hz) turned out to be |
| // reliable, even at slow frame rates. |
| 16, |
| "Notification times are relative to the expected time origins"); |
| |
| assert_equals(topWindowEntries.length, 2, "Top window observer has two notifications."); |
| assert_between_inclusive( |
| topWindowEntries[1].time, |
| topWindowTimeBeforeNotification, |
| topWindowTimeAfterNotification, |
| "Notification to top window observer is within the expected range."); |
| |
| assert_equals(iframeWindowEntries.length, 2, "Iframe observer has two notifications."); |
| assert_between_inclusive( |
| iframeWindowEntries[1].time, |
| iframeWindowTimeBeforeNotification, |
| iframeWindowTimeAfterNotification, |
| "Notification to iframe observer is within the expected range."); |
| } |
| </script> |
