<!DOCTYPE html>
<html>
<head>
<style>
.scrollable_region {
    width: 680px;
}

.contents {
    height: 1036px;
    width: 100%;
    background-image: repeating-linear-gradient(silver, white 200px);
}
</style>
<script src="../../../resources/ui-helper.js"></script>
<script src="../../../resources/js-test-pre.js"></script>
<script>
    jsTestIsAsync = true;

    var divTarget;
    var pageScrollPositionBefore;
    var divScrollPositionBefore;

    function checkForScroll()
    {
        // The div should not have scrolled at all.
        var pageScrollPositionAfter = document.scrollingElement.scrollTop;
        var divScrollPositionAfter = divTarget.scrollTop;

        if (divScrollPositionBefore != divScrollPositionAfter)
            testFailed("Scrollable div consumed wheel events.");
        else
            testPassed("Scrollable div did not receive wheel events.");

        finishJSTest();
    }

    async function scrollTest()
    {
        pageScrollPositionBefore = document.scrollingElement.scrollTop;

        divTarget = document.getElementById('target');

        divScrollPositionBefore = divTarget.scrollTop;

        // Scroll the #source until we reach the #target.
        var startPosX = Math.round(divTarget.offsetLeft) + 20;
        var startPosY = Math.round(divTarget.offsetTop) - 42; // Slightly more than one wheel scroll away from the iframe

        await UIHelper.startMonitoringWheelEvents();
        eventSender.mouseMoveTo(startPosX, startPosY); // Make sure we are just outside the iframe
        debug("Mouse moved to (" + startPosX + ", " + startPosY + ")");
        eventSender.mouseScrollByWithWheelAndMomentumPhases(0, -1, 'began', 'none');
        eventSender.mouseScrollByWithWheelAndMomentumPhases(0, -1, 'changed', 'none');
        eventSender.mouseScrollByWithWheelAndMomentumPhases(0, -1, 'changed', 'none');
        eventSender.mouseScrollByWithWheelAndMomentumPhases(0, 0, 'ended', 'none');
        eventSender.mouseScrollByWithWheelAndMomentumPhases(0, -1, 'none', 'begin');
        eventSender.mouseScrollByWithWheelAndMomentumPhases(0, -1, 'none', 'continue');
        eventSender.mouseScrollByWithWheelAndMomentumPhases(0, 0, 'none', 'end');
        await UIHelper.waitForScrollCompletion();
        checkForScroll();
    }

    function setupTopLevel()
    {
        description("Tests that a scrollable div doesn't consume wheel events when scroll is latched to main frame.");
        if (window.eventSender) {
            setTimeout(scrollTest, 0);
            return;
        }

        var messageLocation = document.getElementById('parent');
        var message = document.createElement('div');
        message.innerHTML = "<p>To manually run this test, place the mouse pointer "
            + "at the top of the page, and then use the mouse wheel or a two-finger swipe to scroll the "
            + "down past the div.<p>"
            + "<p>The scrollable div should not scroll.</p>";
        messageLocation.appendChild(message);
        finishJSTest();
    }

    window.addEventListener('load', () => {
        setupTopLevel();
    }, false);
</script>
</head>
<body>
<div id="parent" style="height: 2000px; width: 2000px;">
    <div id="source" style="height: 100px; width: 500px;">
        Put mouse here and flick downwards
    </div>
    <div class="scrollable_region">
        <h3>Scrollable Region</h3>
        <div id="target" style='overflow-y: auto; overflow-x: hidden; max-height: 485px;'>
            <div class="contents">
                Scrolled contents
            </div>
        </div>
    </div>
</div>
<div id="console"></div>
<script src="../../../resources/js-test-post.js"></script>
</body>
</html>
