<!DOCTYPE html>
<html>
<head>
<link rel="help" href="https://drafts.csswg.org/css-scroll-snap"/>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/dom/events/scrolling/scroll_support.js"></script>
<script src="/resources/testdriver.js"></script>
<script src="/resources/testdriver-actions.js"></script>
<script src="/resources/testdriver-vendor.js"></script>
<script src="resources/common.js" ></script>
</head>
<body>
<style>
.scroller {
overflow: scroll;
width: 450px;
height: 450px;
border: solid 1px black;
scroll-snap-type: both mandatory;
position: relative;
resize: both;
}
.large-space {
height: 300vh;
width: 300vw;
position: absolute;
}
.snap {
scroll-snap-align: start;
}
.box {
width: 200px;
height: 200px;
background-color: green;
position: absolute;
}
.inner {
width: 50px;
height: 50px;
background-color: yellow;
}
#box2 {
top: 0px;
left: 100px;
}
#box3 {
top: 100px;
left: 0px;
}
</style>
<div class="scroller" id="scroller">
<div class="large-space"><div>
<div id="box1" class="snap box">Box 1</div>
<div id="box2" class="inner snap box">Box 2</div>
<div id="box3" class="inner snap box">Box 3</div>
</div>
<script>
window.onload = () => {
const scroller = document.getElementById("scroller");
const boxes = document.querySelectorAll(".snap.box");
function box(n) {
return boxes[n - 1];
}
promise_test(async (t) => {
await waitForCompositorCommit();
// Box 2 should be selected as the target in the y axis despite Box 1's
// being a common target in both axes because Box 2 is nested within
// Box 1.
await runScrollSnapSelectionVerificationTest(t, scroller,
/*aligned_elements_x=*/[],
/*aligned_elements_y=*/[box(1), box(2)],
/*axis=*/ "y",
/*expected_target_x=*/null,
/*expected_target_y=*/box(2));
// Box 3 should be selected as the target in the x axis despite Box 1's
// being a common target in both axes because Box 3 is nested within
// Box 1.
await runScrollSnapSelectionVerificationTest(t, scroller,
/*aligned_elements_x=*/[box(1), box(3)],
/*aligned_elements_y=*/[],
/*axis=*/"x",
/*expected_target_x=*/box(3));
}, "scroller prefers nested area over area aligned in both axes.");
}
</script>
</body>
</html>
Codebase Browser
chromium