iframe-and-main-frame-transition-old-main-new-iframe.html

<!DOCTYPE html>
<html class=reftest-wait>
<title>View transitions: iframe and main frame transition at the same time</title>
<link rel="help" href="https://drafts.csswg.org/css-view-transitions-1/">
<link rel="author" href="mailto:[email protected]">
<link rel="match" href="iframe-and-main-frame-transition-old-main-new-iframe-ref.html">
<script src="/common/reftest-wait.js"></script>
<style>
iframe {
  position: fixed;
  top: 0;
  left: 0;
  width: 50vw;
  height: 50vh;
}

/* Keep showing the screenshot for the main frame */
::view-transition-group(root) {
  animation-duration: 300s;
}
::view-transition-old(root) {
  animation: unset;
  opacity: 1;
}
::view-transition-new(root) {
  animation: unset;
  opacity: 0;
}
</style>

<iframe srcdoc="
<style>
  /* The iframe is showing live DOM */
  ::view-transition-group(root) {
    animation-duration: 300s;
  }
  ::view-transition-new(root) {
    animation: unset;
    opacity: 1;
  }
  ::view-transition-old(root) {
    animation: unset;
    opacity: 0;
  }
</style>
<body></body>
"></iframe>
<script>
  onload = runTest;

  async function startTransition(document, oldColor, newColor) {
    document.documentElement.style.background = oldColor;
    await document.startViewTransition(() => {
      document.documentElement.style.background = newColor;
    }).ready;
  }

  async function runTest() {
    const iframeDocument = document.querySelector("iframe").contentDocument;
    await startTransition(iframeDocument, "blue", "lightblue");

    await startTransition(document, "green", "lightgreen");

    takeScreenshot();
  }
</script>

chromium/third_party/blink/web_tests/external/wpt/css/css-view-transitions/iframe-and-main-frame-transition-old-main-new-iframe.html