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Test Info: Warnings

  • This test gets skipped with pattern: OR toolkit == 'android' OR toolkit == 'cocoa'
<title>Test for Bug 1203140</title>
<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>
<link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
<p id="display"></p>
<div id="content" style="overflow-y:scroll; height: 400px">
<p>The box below has a touch listener and a passive wheel listener. With touch events disabled, APZ shouldn't wait for any listeners.</p>
<div id="box" style="width: 200px; height: 200px; background-color: blue"></div>
<div style="height: 1000px; width: 10px">Div to make 'content' scrollable</div>
<pre id="test">
<script type="application/javascript">
const kResponseTimeoutMs = 2 * 60 * 1000; // 2 minutes
function takeSnapshots(e) {
// Grab some snapshots, and make sure some of them are different (i.e. check
// the page is scrolling in the compositor, concurrently with this wheel
// listener running).
// Note that we want this function to take less time than the content response
// timeout, otherwise the scrolling will start even if we haven't returned,
// and that would invalidate purpose of the test.
var start =;
var lastSnapshot = null;
var success = false;
// Get the position of the 'content' div relative to the screen
var rect = rectRelativeToScreen(document.getElementById("content"));
for (var i = 0; i < 10; i++) {
var snapshot = getSnapshot(rect);
// dump("Took snapshot " + snapshot + "\n"); // this might help with debugging
if (lastSnapshot && lastSnapshot != snapshot) {
ok(true, "Found some different pixels in snapshot " + i + " compared to previous");
success = true;
lastSnapshot = snapshot;
ok(success, "Found some snapshots that were different");
ok(( - start) < kResponseTimeoutMs, "Snapshotting ran quickly enough");
// Until now, no scroll events will have been dispatched to content. That's
// because scroll events are dispatched on the main thread, which we've been
// hogging with the code above. At this point we restore the normal refresh
// behaviour and let the main thread go back to C++ code, so the scroll events
// fire and we unwind from the main test continuation.
async function test() {
var box = document.getElementById("box");
// Ensure the div is layerized by scrolling it
await promiseMoveMouseAndScrollWheelOver(box, 10, 10);
box.addEventListener("touchstart", function(e) {
ok(false, "This should never be run");
box.addEventListener("wheel", takeSnapshots, { capture: false, passive: true });
// Let the event regions and layerization propagate to the APZ
await promiseAllPaintsDone();
await promiseOnlyApzControllerFlushed();
await promiseNativeMouseEventWithAPZAndWaitForEvent({
type: "mousemove",
target: box,
offsetX: 10,
offsetY: 10,
// Take over control of the refresh driver and compositor
var utils = SpecialPowers.DOMWindowUtils;
// Trigger an APZ scroll using a wheel event. If APZ is waiting for a
// content response, it will wait for takeSnapshots to finish running before
// it starts scrolling, which will cause the checks in takeSnapshots to fail.
await promiseNativeWheelAndWaitForScrollEvent(box, 10, 10, 0, -50);
if (isApzEnabled()) {
// Disable touch events, so that APZ knows not to wait for touch listeners.
// Also explicitly set the content response timeout, so we know how long it
// is (see comment in takeSnapshots).
// Finally, enable smooth scrolling, so that the wheel-scroll we do as part
// of the test triggers an APZ animation rather than doing an instant scroll.
// Note that this pref doesn't work for the synthesized wheel events on OS X,
// those are hard-coded to be instant scrolls.
pushPrefs([["dom.w3c_touch_events.enabled", 0],
["apz.content_response_timeout", kResponseTimeoutMs],
["general.smoothscroll", true]])
.then(SimpleTest.finish, SimpleTest.finishWithFailure);