wheel-event-transactions-target-elements.html

<!DOCTYPE HTML>
<html>
<head>
<meta charset="utf-8">
<meta name="viewport" content="width=device-width,initial-scale=1,minimum-scale=1">
<link rel="stylesheet" type="text/css" href="/fonts/ahem.css"/>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/testdriver.js"></script>
<script src="/resources/testdriver-actions.js"></script>
<script src="/resources/testdriver-vendor.js"></script>
<script src="scroll_support.js"></script>
<style>
body {
  margin: 0;
  padding: 0;
  height: 200vh;
}

.spacer {
  width: 100%;
  height: 25px;
  padding: 0;
  margin: 0;
  font: 25px/1 Ahem;
}

</style>
<head>
<body>
<div id="firstRootSpacer" class="spacer" style="background: green">X</div>
<div id="secondRootSpacer" class="spacer" style="background: blue"></div>
</body>

<script>

promise_test(async (t) => {
  // Wheel event transactions target elements, not nodes. A wheel event
  // transaction that begins over a text node should have an event target for
  // the containing element.
  await waitForCompositorReady();

  await waitForCompositorCommit();

  let wheelEventTargets = [];

  window.addEventListener("wheel", (e) => {
    wheelEventTargets.push(e.target);
  }, {passive: true});

  await waitForCompositorCommit();

  await new test_driver.Actions()
    .addWheel("wheel1")
    .scroll(12, 12, 0, 30, {origin: "viewport"})
    .pause(1)
    .scroll(12, 12, 0, 30, {origin: "viewport"})
    .send();

  // TODO(dlrobertson): Use the scrollend event here to wait for the
  // wheel scroll to finish instead of waitForAnimationEnd().
  await waitForAnimationEnd(() => { return document.scrollingElement.scrollTop; });
  await waitForCompositorCommit();

  // All of the wheel events should have the first div as their target.
  wheelEventTargets.forEach((wheelEventTarget, i) => {
    assert_equals(wheelEventTarget, firstRootSpacer,
                  "Wheel event at index `" + i + "` does not have the expected target");
  });

  assert_greater_than(document.scrollingElement.scrollTop, 0, "The document has scrolled");
}, "Wheel event transactions target elements");
</script>
</html>
chromium/third_party/blink/web_tests/external/wpt/dom/events/scrolling/wheel-event-transactions-target-elements.html
