<!DOCTYPE HTML>
<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>
#scrollableDiv {
  width: 200px;
  height: 200px;
  overflow: scroll;
}

#innerDiv {
  width: 400px;
  height: 400px;
}
</style>

<body style="margin:0" onload=runTest()>
<div id="scrollableDiv">
  <div id="innerDiv">
  </div>
</div>
</body>

<script>
var scrolling_div = document.getElementById('scrollableDiv');
var overscrolled_x_delta = 0;
var overscrolled_y_delta = 0;
function onOverscroll(event) {
  assert_false(event.cancelable);
  assert_false(event.bubbles);
  overscrolled_x_delta = event.deltaX;
  overscrolled_y_delta = event.deltaY;
}
scrolling_div.addEventListener("overscroll", onOverscroll);

function runTest() {
  promise_test (async (t) => {
    // Make sure that no overscroll event is sent to document.
    document.addEventListener("overscroll",
        t.unreached_func("Document got unexpected overscroll event."));
    await waitForCompositorCommit();

    // Do a horizontal scroll and wait for overscroll event.
    await touchScrollInTarget(300, scrolling_div , 'right');
    await waitFor(() => { return overscrolled_x_delta > 0; },
        'Scroller did not receive overscroll event after horizontal scroll.');
    assert_equals(scrolling_div.scrollWidth - scrolling_div.scrollLeft,
                scrolling_div.clientWidth);

    overscrolled_x_delta = 0;
    overscrolled_y_delta = 0;

    // Do a vertical scroll and wait for overscroll event.
    await touchScrollInTarget(300, scrolling_div, 'down');
    await waitFor(() => { return overscrolled_y_delta > 0; },
        'Scroller did not receive overscroll event after vertical scroll.');
    assert_equals(scrolling_div.scrollHeight - scrolling_div.scrollTop,
                scrolling_div.clientHeight);
  }, 'Tests that the scrolled element gets overscroll event after fully scrolling by touch.');
}
</script>
