<!DOCTYPE html>
<script src="../resources/js-test.js"></script>
<script src="helper-functions.js"></script>
<div style="width:100%; height:700px;"></div>
<iframe id="target-iframe" src="../resources/intersection-observer-subframe.html" style="height: 100px; overflow-y: scroll"></iframe>
<div style="width:100%; height:700px;"></div>

<script>
description("Simple intersection observer test with no explicit root and target in an iframe.");
var entries = [];
var observer = new IntersectionObserver(changes => { entries = entries.concat(changes) }, {});
var targetIframe = document.getElementById("target-iframe");
var target;
var iframeScroller;

targetIframe.onload = function() {
  target = targetIframe.contentDocument.getElementById("target");
  iframeScroller = targetIframe.contentDocument.scrollingElement;
  observer.observe(target);
  entries = entries.concat(observer.takeRecords());
  shouldBeEqualToNumber("entries.length", 0);
  // See README for explanation of double RAF.
  requestAnimationFrame(() => { requestAnimationFrame(step0) });
}

function step0() {
  entries = entries.concat(observer.takeRecords());
  shouldBeEqualToNumber("entries.length", 0);
  document.scrollingElement.scrollTop = 200;
  requestAnimationFrame(step1);
}

function step1() {
  entries = entries.concat(observer.takeRecords());
  shouldBeEqualToNumber("entries.length", 0);
  iframeScroller.scrollTop = 250;
  requestAnimationFrame(step2);
}

function step2() {
  entries = entries.concat(observer.takeRecords());
  shouldBeEqualToNumber("entries.length", 1);
  if (entries.length > 0) {
    shouldBeEqualToNumber("entries[0].boundingClientRect.left", 8);
    shouldBeEqualToNumber("entries[0].boundingClientRect.right", 108);
    shouldBeEqualToNumber("entries[0].boundingClientRect.top", -42);
    shouldBeEqualToNumber("entries[0].boundingClientRect.bottom", 58);
    shouldBeEqualToNumber("entries[0].intersectionRect.left", 8);
    shouldBeEqualToNumber("entries[0].intersectionRect.right", 108);
    shouldBeEqualToNumber("entries[0].intersectionRect.top", 0);
    shouldBeEqualToNumber("entries[0].intersectionRect.bottom", 58);
    shouldBeEqualToNumber("entries[0].rootBounds.left", 0);
    shouldBeEqualToNumber("entries[0].rootBounds.right", 785);
    shouldBeEqualToNumber("entries[0].rootBounds.top", 0);
    shouldBeEqualToNumber("entries[0].rootBounds.bottom", 600);
    shouldEvaluateToSameObject("entries[0].target", target);
  }
  document.scrollingElement.scrollTop = 100;
  requestAnimationFrame(step3);
}

function step3() {
  entries = entries.concat(observer.takeRecords());
  shouldBeEqualToNumber("entries.length", 2);
  if (entries.length > 1) {
    shouldBeEqualToNumber("entries[1].boundingClientRect.left", 8);
    shouldBeEqualToNumber("entries[1].boundingClientRect.right", 108);
    shouldBeEqualToNumber("entries[1].boundingClientRect.top", -42);
    shouldBeEqualToNumber("entries[1].boundingClientRect.bottom", 58);
    shouldBeEqualToNumber("entries[1].intersectionRect.left", 0);
    shouldBeEqualToNumber("entries[1].intersectionRect.right", 0);
    shouldBeEqualToNumber("entries[1].intersectionRect.top", 0);
    shouldBeEqualToNumber("entries[1].intersectionRect.bottom", 0);
    shouldBeEqualToNumber("entries[1].rootBounds.left", 0);
    shouldBeEqualToNumber("entries[1].rootBounds.right", 785);
    shouldBeEqualToNumber("entries[1].rootBounds.top", 0);
    shouldBeEqualToNumber("entries[1].rootBounds.bottom", 600);
    shouldEvaluateToSameObject("entries[1].target", target);
  }
  finishJSTest();
  document.scrollingElement.scrollTop = 0;
}
</script>