vertical-scroll-touch-block.html | Explore in Territory

<!DOCTYPE html>
<style>
body, div, html {
  height: 100%;
  width: 100%;
  overflow: hidden;
}
p {
  margin-bottom: 1000px;
  margin-right: 1000px;
}
</style>
<body>
  <div id="blocker">
    <p>This page blocks 'touchstart' and 'touchmove'.</p>
  </div>
  <script>
    function doSomethingUnimportant(e) {
      return false !== e;
    }

    function preventDefault(e) {
      e.preventDefault();
    }

    document.addEventListener("touchstart", doSomethingUnimportant, {passive: false});
    document.addEventListener("touchmove", doSomethingUnimportant, {passive: false});

    function messageHandler(e) {
      let msg = e.data;
      let element = document.querySelector(msg.query);
      if (msg.prevent) {
        element.addEventListener(msg.event_type, preventDefault, {passive: false});
      } else {
        element.addEventListener(msg.event_type, doSomethingUnimportant);
      }
      e.source.postMessage(msg, "*");
    }

    window.addEventListener("message", messageHandler);
  </script>
</body>

chromium/third_party/blink/web_tests/external/wpt/feature-policy/experimental-features/resources/vertical-scroll-touch-block.html