transform-containing-block-and-scrolling-area-for-fixed.html

<!DOCTYPE html>
<meta charset="utf-8">
<title>CSS transforms: Transformed elements with overflow: hidden create scrolling areas for fixed descendants</title>
<link rel="author" title="Martin Robinson" href="mailto:[email protected]">
<link rel="help" href="https://drafts.csswg.org/css-transforms-1/#transform-rendering">
<link rel="help" href="https://drafts.csswg.org/css-transforms-1/#transform-property">
<link rel="match" href="transform-containing-block-and-scrolling-area-for-fixed-ref.html">
<meta name="assert" content="For elements whose layout is governed by the CSS box model, any value other than none for the transform results in the creation of both a stacking context and a containing block. The object acts as a containing block for fixed positioned descendants.">
<meta name="assert" content="The object acts as a containing block for fixed positioned descendants, but also creates scrolling areas for them."
<meta name="flags" content="dom">
<style>
  html, body { margin: 0; padding: 0 }
  #transformed {
    transform: translateX(10px) translateY(10px);
    width: 200px;
    height: 200px;
    background: grey;
    overflow: hidden;
  }

  #fixed {
    position: fixed;
    width: 50px;
    height: 50px;
    top: 50px;
    left: 50px;
    background: green;
  }

  #spacer {
    height: 10000px;
    width: 10000px;
  }
</style>
<body>
  <div id="transformed">
    <div id="fixed"></div>
    <div id="spacer"></div>
  </div>
  <script>
    document.getElementById('transformed').scrollTo(50, 50);
  </script>
</body>

chromium/third_party/blink/web_tests/external/wpt/css/css-transforms/transform-containing-block-and-scrolling-area-for-fixed.html