<!
DOCTYPE HTML>
<!--
https://bugzilla.mozilla.org/show_bug.cgi?id=1453425
-->
<
html>
<
head>
<
title>Test for relative scroll offset updates (Bug 1453425)</
title>
<
meta charset=
"utf-8">
<
script src=
"/tests/SimpleTest/SimpleTest.js"></
script>
<
script src=
"/tests/SimpleTest/EventUtils.js"></
script>
<
script src=
"/tests/SimpleTest/paint_listener.js"></
script>
<
script type=
"application/javascript" src=
"apz_test_utils.js"></
script>
<
script type=
"application/javascript" src=
"apz_test_native_event_utils.js"></
script>
<
style type=
"text/css">
#
frame {
width: 200px;
height: 400px;
overflow: scroll;
border: 1px solid black;
}
#first {
width: 200px;
height: 108px;
background-color: red;
}
#second {
width: 200px;
height: 692px;
background-color: green;
}
</
style>
</
head>
<
body>
<
div id=
"frame">
<
div id=
"first"></
div>
<
div id=
"second"></
div>
</
div>
<
script type=
"application/javascript">
async function test() {
var utils = SpecialPowers.DOMWindowUtils;
var elm = document.querySelector(
"#frame");
// Set a zero-margin displayport to ensure that the element is async-scrollable
utils.setDisplayPortMarginsForElement(0, 0, 0, 0, elm, 0);
elm.scrollTop = 0;
// Take over control of the refresh driver and don
't allow a layer
// transaction until the main thread and APZ have processed two different
// scrolls.
await promiseApzFlushedRepaints();
utils.advanceTimeAndRefresh(0);
// Scroll instantly on the main thread by (0, 100).
elm.scrollBy(0, 100);
// We are not using `scroll-behavior`
is(elm.scrollTop, 100,
"the main thread scroll should be instant");
// Dispatch a wheel event to have APZ scroll by (0, 8). Wait for the wheel
// event to ensure that the APZ has processed the scroll.
await promiseNativeWheelAndWaitForWheelEvent(elm, 40, 40, 0, -8);
// APZ should be handling the wheel scroll
is(elm.scrollTop, 100,
"the wheel scroll should be handled by APZ");
// Restore control of the refresh driver, allowing the main thread to send a
// layer transaction containing the (0, 100) scroll.
utils.restoreNormalRefresh();
// Wait for all paints to finish and for the main thread to receive pending
// repaint requests with the scroll offset from the wheel event.
await promiseApzFlushedRepaints();
// The main thread scroll should not have overidden the APZ scroll, and we
// should see the effects of both scrolls.
ok(elm.scrollTop > 100, `expected element.scrollTop > 100. got element.scrollTop = ${elm.scr
ollTop}`);
}
if (isApzEnabled()) {
SimpleTest.waitForExplicitFinish();
// Receiving a relative scroll offset update can cause scroll animations to
// be cancelled. This should be fixed, but for now we can still test this
// by disabling smooth scrolling.
pushPrefs([["general.smoothScroll", false]])
.then(waitUntilApzStable)
.then(test)
.then(SimpleTest.finish, SimpleTest.finishWithFailure);
}
</script>
</body>
</html>
