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<!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;
}
#root {
position: absolute;
top: 0;
left: 0;
width: 150px;
height: 200px;
overflow-y: scroll;
}
#target1, #target2, #target3, #target4 {
width: 100px;
height: 100px;
}
#target1 {
background-color: green;
}
#target2 {
background-color: red;
}
#target3 {
background-color: blue;
}
#target4 {
background-color: yellow;
}
</style>
<div id="root">
<div id="target1"></div>
<div id="target2"></div>
<div id="target3"></div>
</div>
<script>
var entries = [];
var observer;
runTestCycle(function() {
var root = document.getElementById('root');
var target1 = document.getElementById('target1');
var target2 = document.getElementById('target2');
var target3 = document.getElementById('target3');
assert_true(!!root, "root element exists.");
assert_true(!!target1, "target1 element exists.");
assert_true(!!target2, "target2 element exists.");
assert_true(!!target3, "target3 element exists.");
observer = new IntersectionObserver(function(changes) {
entries = entries.concat(changes);
}, { root: root });
observer.observe(target1);
observer.observe(target2);
observer.observe(target3);
entries = entries.concat(observer.takeRecords());
assert_equals(entries.length, 0, "No initial notifications.");
runTestCycle(step0, "Rects in initial notifications should report initial positions.");
}, "isIntersecting changes should trigger notifications.");
function step0() {
assert_equals(entries.length, 3, "Has 3 initial notifications.");
checkRect(entries[0].boundingClientRect, [0, 100, 0, 100], "Check 1st entry rect");
assert_equals(entries[0].target.id, 'target1', "Check 1st entry target id.");
checkIsIntersecting(entries, 0, true);
checkRect(entries[1].boundingClientRect, [0, 100, 100, 200], "Check 2nd entry rect");
assert_equals(entries[1].target.id, 'target2', "Check 2nd entry target id.");
checkIsIntersecting(entries, 1, true);
checkRect(entries[2].boundingClientRect, [0, 100, 200, 300], "Check 3rd entry rect");
assert_equals(entries[2].target.id, 'target3', "Check 3rd entry target id.");
checkIsIntersecting(entries, 2, true);
runTestCycle(step1, "Set scrollTop=100 and check for no new notifications.");
root.scrollTop = 100;
}
function step1() {
assert_equals(entries.length, 3, "Has 3 total notifications because isIntersecting did not change.");
runTestCycle(step2, "Add 4th target.");
root.scrollTop = 0;
var target4 = document.createElement('div');
target4.setAttribute('id', 'target4');
root.appendChild(target4);
observer.observe(target4);
}
function step2() {
assert_equals(entries.length, 4, "Has 4 total notifications because 4th element was added.");
checkRect(entries[3].boundingClientRect, [0, 100, 300, 400], "Check 4th entry rect");
assert_equals(entries[3].target.id, 'target4', "Check 4th entry target id.");
checkIsIntersecting(entries, 3, false);
assert_equals(entries[3].intersectionRatio, 0, 'target4 initially has intersectionRatio of 0.');
runTestCycle(step3, "Set scrollTop=100 and check for one new notification.");
root.scrollTop = 100;
}
function step3() {
assert_equals(entries.length, 5, "Has 5 total notifications.");
checkRect(entries[4].boundingClientRect, [0, 100, 200, 300], "Check 5th entry rect");
assert_equals(entries[4].target.id, 'target4', "Check 5th entry target id.");
checkIsIntersecting(entries, 4, true);
assert_equals(entries[4].intersectionRatio, 0, 'target4 still has intersectionRatio of 0.');
root.scrollTop = 0; // reset to make it easier to refresh and run the test
}
</script>
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