css/css-view-transitions/dialog-in-top-layer-during-transition-new.html

<!DOCTYPE html>
<html class=reftest-wait>
<title>View transitions: element in top layer during transition</title>
<link rel="help" href="https://drafts.csswg.org/css-view-transitions-1/">
<link rel="author" href="mailto:khushalsagar@chromium.org">
<link rel="match" href="dialog-in-top-layer-during-transition-ref.html">

<script src="/common/reftest-wait.js"></script>
<style>
#target {
  width: 100px;
  height: 100px;
  background: lightblue;

  border: unset;
  margin: 0;
  padding: 0;

  view-transition-name: dialog;
  outline: none;
}

#target::backdrop {
  width: 100px;
  height: 100px;
  background: grey;

  view-transition-name: backdrop;
}

.hidden {
  contain: paint;
  width: 10px;
  height: 10px;
  background: grey;
  view-transition-name: hidden;
}

html::view-transition-group(hidden) { animation-duration: 300s; }
html::view-transition-image-pair(hidden) { animation: unset; opacity: 0; }

html::view-transition-group(backdrop) {
  position: fixed;
  top: 120px;
  left: 0;
}

html::view-transition-new(backdrop), html::view-transition-new(dialog) {
  opacity: 1;
  animation: unset;
}
</style>

<dialog id="target"></dialog>
<div id=hidden class=hidden></div>

<script>
failIfNot(document.startViewTransition, "Missing document.startViewTransition");

async function runTest() {
  const transition = document.startViewTransition(() => {
    target.showModal();
    target.style.background = "lightgreen";
  });
  await transition.ready;
  takeScreenshot();
}
onload = () => requestAnimationFrame(() => requestAnimationFrame(runTest));
</script>