chromium/third_party/blink/web_tests/external/wpt/css/css-view-transitions/shared-transition-shapes.manual.html

<!DOCTYPE html>
<html>
<title>View transitions of different elements and shapes</title>
<link rel="help" href="https://github.com/vmpstr/view-transitions">
<link rel="author" href="mailto:[email protected]">

<style>
body {
  background: lightpink;
}

#container {
  width: max-content;
  position: relative;
}

.left {
  left: 50px;
}
.right {
  left: 550px;
}

div {
  margin: 10px;
  contain: paint;
}

.square {
  width: 100px;
  height: 100px;
  background: green;
}
.rounded {
  width: 100px;
  height: 100px;
  background: green;
  border-radius: 20%;
}
.translucent {
  opacity: 0.5;
}
.text {
  width: 100px;
  height: 100px;
}
</style>

<input id=toggle type=button value="Toggle!"></input>
<span>Same shape should move right and left</span>
<div id=container class=left>
  <div id=e1 class=square></div>
  <div id=e2 class=rounded></div>
  <div id=e3 class="square translucent"></div>
  <div id=e4 class="rounded translucent"></div>
  <div id=e5 class=text>Lorem Ipsum</div>
</div>

<script>
let classes = ["left", "right"]
let i = 0;
async function runAnimation() {
  e1.style.viewTransitionName = "e1";
  e2.style.viewTransitionName = "e2";
  e3.style.viewTransitionName = "e3";
  e4.style.viewTransitionName = "e4";
  e5.style.viewTransitionName = "e5";
  let t = document.startViewTransition(() => {
    container.classList.remove(classes[i]);
    i = (i + 1) % classes.length;
    container.classList.add(classes[i]);
  });
  await t.finished;
}

function init() {
  toggle.addEventListener("click", runAnimation);
}
onload = init;
</script>