1<!DOCTYPE HTML>
2<script src="/resources/testharness.js"></script>
3<script src="/resources/testharnessreport.js"></script>
4<script src="/resources/testdriver.js"></script>
5<script src="/resources/testdriver-actions.js"></script>
6<script src="/resources/testdriver-vendor.js"></script>
7<script src="scroll_support.js"></script>
8<style>
9#overscrollXDiv {
10  width: 600px;
11  height: 600px;
12  overflow: scroll;
13  overscroll-behavior-x: contain;
14}
15#overscrollYDiv {
16  width: 500px;
17  height: 500px;
18  overflow: scroll;
19  overscroll-behavior-y: none;
20}
21#targetDiv {
22  width: 400px;
23  height: 400px;
24  overflow: scroll;
25}
26.content {
27  width:800px;
28  height:800px;
29}
30</style>
31
32<body style="margin:0" onload=runTest()>
33<div id="overscrollXDiv">
34  <div class=content>
35    <div id="overscrollYDiv">
36      <div class=content>
37        <div id="targetDiv">
38          <div class="content">
39          </div>
40        </div>
41      </div>
42    </div>
43  </div>
44</div>
45</body>
46
47<script>
48var target_div = document.getElementById('targetDiv');
49var overscrolled_x_delta = 0;
50var overscrolled_y_delta = 0;
51function onOverscrollX(event) {
52  assert_false(event.cancelable);
53  assert_false(event.bubbles);
54  overscrolled_x_delta = event.deltaX;
55}
56function onOverscrollY(event) {
57  assert_false(event.cancelable);
58  assert_false(event.bubbles);
59  overscrolled_y_delta = event.deltaY;
60}
61// Test that both "onoverscroll" and addEventListener("overscroll"... work.
62document.getElementById('overscrollXDiv').onoverscroll = onOverscrollX;
63document.getElementById('overscrollYDiv').
64    addEventListener("overscroll", onOverscrollY);
65
66function runTest() {
67  promise_test (async (t) => {
68    // Make sure that no overscroll event is sent to document or target_div.
69    document.addEventListener("overscroll",
70        t.unreached_func("Document got unexpected overscroll event."));
71    target_div.addEventListener("overscroll",
72        t.unreached_func("target_div got unexpected overscroll event."));
73    await waitForCompositorCommit();
74    // Scroll up on target div and wait for the element with overscroll-y to get
75    // overscroll event.
76    await touchScrollInTarget(300, target_div, 'up');
77    await waitFor(() => { return overscrolled_y_delta < 0; },
78        'Expected element did not receive overscroll event after scroll up on ' +
79        'target.');
80    assert_equals(target_div.scrollTop, 0);
81
82    // Scroll left on target div and wait for the element with overscroll-x to
83    // get overscroll event.
84    await touchScrollInTarget(300, target_div, 'left');
85    await waitFor(() => { return overscrolled_x_delta < 0; },
86        'Expected element did not receive overscroll event after scroll left ' +
87        'on target.');
88    assert_equals(target_div.scrollLeft, 0);
89  }, 'Tests that the last element in the cut scroll chain gets overscroll ' +
90     'event when no element scrolls by touch.');
91}
92</script>
93