| <!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> | 
 | /* Cobalt does not implement HTML5 spec for body margin. */ | 
 | body { | 
 |   margin: 8px; | 
 | } | 
 | pre, #log { | 
 |   position: absolute; | 
 |   top: 0; | 
 |   left: 200px; | 
 | } | 
 | .spacer { | 
 |   /* Cobalt does not support calc */ | 
 |   height: 100vh; | 
 | } | 
 | #root { | 
 |   overflow: scroll; | 
 |   height: 200px; | 
 |   border: 3px solid black; | 
 | } | 
 | #target { | 
 |   width: 100px; | 
 |   height: 100px; | 
 |   background-color: green; | 
 | } | 
 | </style> | 
 |  | 
 | <div class="spacer"></div> | 
 | <div id="root"> | 
 |   <div style="height: 300px;"></div> | 
 |   <div id="target"></div> | 
 | </div> | 
 | <div class="spacer"></div> | 
 |  | 
 | <script> | 
 | var vh = window.innerHeight; | 
 |  | 
 | var entries = []; | 
 | var root, target; | 
 |  | 
 | runTestCycle(function() { | 
 |   target = document.getElementById("target"); | 
 |   assert_true(!!target, "target exists"); | 
 |   root = document.getElementById("root"); | 
 |   assert_true(!!root, "root exists"); | 
 |   var observer = new IntersectionObserver(function(changes) { | 
 |     entries = entries.concat(changes); | 
 |     window.testRunner.DoNonMeasuredLayout(); | 
 |   }, { root: root }); | 
 |   observer.observe(target); | 
 |   entries = entries.concat(observer.takeRecords()); | 
 |   assert_equals(entries.length, 0, "No initial notifications."); | 
 |   runTestCycle(step0, "First rAF"); | 
 | }, "IntersectionObserver in a single document with explicit root."); | 
 | window.testRunner.DoNonMeasuredLayout(); | 
 | window.testRunner.DoNonMeasuredLayout(); | 
 |  | 
 | function step0() { | 
 |   root.style.marginTop = "-200px"; | 
 |   //document.documentElement.scrollTop = vh; | 
 |   runTestCycle(step1, "document.scrollingElement.scrollTop = window.innerHeight."); | 
 |   checkLastEntry(entries, 0, [ 11, 111, vh + 311, vh + 411, 0, 0, 0, 0, 11, 111, vh + 111, vh + 311, false]); | 
 |   window.testRunner.DoNonMeasuredLayout(); | 
 | } | 
 |  | 
 | function step1() { | 
 |   target.style.marginTop = "-150px"; | 
 |   //root.scrollTop = 150; | 
 |   runTestCycle(step2, "root.scrollTop = 150 with root scrolled into view."); | 
 |   assert_equals(entries.length, 1, "No notifications after scrolling frame."); | 
 | } | 
 |  | 
 | function step2() { | 
 |   root.style.marginTop = "0px"; | 
 |   //document.documentElement.scrollTop = 0; | 
 |   runTestCycle(step3, "document.scrollingElement.scrollTop = 0."); | 
 |   const marginOffset = 200 + 150; | 
 |   const topOfTarget = vh + 311 - marginOffset; | 
 |   checkLastEntry(entries, 1, [11, 111, topOfTarget, topOfTarget + 100, 11, 111, topOfTarget, topOfTarget + 50, 11, 111, 111, 311, true]); | 
 |   window.testRunner.DoNonMeasuredLayout(); | 
 | } | 
 |  | 
 | function step3() { | 
 |   target.style.marginTop = "0px"; | 
 |   //root.scrollTop = 0; | 
 |   runTestCycle(step4, "root.scrollTop = 0"); | 
 |   checkLastEntry(entries, 1); | 
 | } | 
 |  | 
 | function step4() { | 
 |   target.style.marginTop = "-150px"; | 
 |   //root.scrollTop = 150; | 
 |   runTestCycle(step5, "root.scrollTop = 150 with root scrolled out of view."); | 
 |   checkLastEntry(entries, 2, [11, 111, vh + 311, vh + 411, 0, 0, 0, 0, 11, 111, vh + 111, vh + 311, false]); | 
 | } | 
 |  | 
 | // This tests that notifications are generated even when the root element is off screen. | 
 | function step5() { | 
 |   checkLastEntry(entries, 3, [11, 111, vh + 161, vh + 261, 11, 111, vh + 161, vh + 211, 11, 111, vh + 111, vh + 311, true]); | 
 | } | 
 | </script> |