<!DOCTYPE HTML>
<html>
    <head>
        <style>
            .verticalGallery {
                width: 100vw;
                height: 600vh;
                margin: 0;
                padding: 0;
                scroll-snap-type: y mandatory;
            }
            .colorBox {
                height: 100vh;
                width: 100vw;
                float: left;
                scroll-snap-align: start;
            }
            #item0 { background-color: red; background-image: url('../../resources/green-blue.png'); background-attachment: fixed;}
            #item1 { background-color: green; }
            #item2 { background-color: blue; }
            #item3 { background-color: aqua; }
            #item4 { background-color: yellow; }
            #item5 { background-color: fuchsia; }
        </style>
        <script src="../../../resources/js-test.js"></script>
        <script>
        window.jsTestIsAsync = true;

        var targetScroller;
        var scrollPositionBeforeGlide;
        var scrollPositionBeforeSnap;

        function checkForScrollSnap()
        {
            // The div should have snapped back to the previous position
            if (targetScroller.scrollTop != scrollPositionBeforeSnap)
                testFailed(`div did not snap back to proper location. (${targetScroller.scrollTop} vs. ${scrollPositionBeforeSnap})`);
            else
                testPassed("div honored snap points.");

            finishJSTest();
        }

        function scrollSnapTest()
        {
            // See where our div lives:
            scrollPositionBeforeSnap = targetScroller.scrollTop;

            var startPosX = targetScroller.offsetLeft + 20;
            var startPosY = targetScroller.offsetTop + 20;
            eventSender.monitorWheelEvents();
            eventSender.mouseMoveTo(startPosX, startPosY); // Make sure we are just outside the iFrame
            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.callAfterScrollingCompletes(checkForScrollSnap);
        }

        function checkForScrollGlide()
        {
            // The div should have scrolled (glided) to the next snap point.
            if (targetScroller.scrollTop == window.innerHeight)
                testPassed("div scrolled to next window.");
            else
                testFailed(`div did not honor snap points. (${targetScroller.scrollTop} vs. ${window.innerHeight})`);

            setTimeout(scrollSnapTest, 0);
        }

        function scrollGlideTest()
        {
            scrollPositionBeforeGlide = targetScroller.scrollTop;

            var startPosX = targetScroller.offsetLeft + 20;
            var startPosY = targetScroller.offsetTop + 20;
            eventSender.monitorWheelEvents();
            eventSender.mouseMoveTo(startPosX, startPosY); // Make sure we are just outside the iFrame
            eventSender.mouseScrollByWithWheelAndMomentumPhases(0, -1, 'began', 'none');
            eventSender.mouseScrollByWithWheelAndMomentumPhases(0, -1, 'changed', '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, -4, 'none', 'continue');
            eventSender.mouseScrollByWithWheelAndMomentumPhases(0, 0, 'none', 'end');
            eventSender.callAfterScrollingCompletes(checkForScrollGlide);
        }

        function onLoad()
        {
            targetScroller = document.scrollingElement;
            if (window.eventSender) {
                internals.setPlatformMomentumScrollingPredictionEnabled(false);
                setTimeout(scrollGlideTest, 0);
            } else {
                var messageLocation = document.getElementById('item0');
                var message = document.createElement('div');
                message.innerHTML = "<p>This test is better run under DumpRenderTree. To manually test it, place the mouse pointer<br/>"
                    + "inside the red region at the top of the page, and then use the mouse wheel or a two-finger swipe to make a<br/>"
                    + "small swipe gesture with some momentum.<br/><br/>"
                    + "The region should scroll to show a green region.<br/><br/>"
                    + "Next, perform a small scroll gesture that does not involve momentum. You should begin to see one of the colors<br/>"
                    + "to the left (or right) of the current green box. When you release the wheel, the region should scroll back so<br/>"
                    + "that the region is a single color.<br/><br/>"
                    + "You should also be able to repeat these test steps for the vertical region below.</p>";
                messageLocation.appendChild(message);
            }
        }
        </script>
    </head>
    <body onload="onLoad();" class="verticalGallery">
        <div id="item0" class="colorBox"><div id="console"></div></div>
        <div id="item1" class="colorBox"></div>
        <div id="item2" class="colorBox"></div>
        <div id="item3" class="colorBox"></div>
        <div id="item4" class="colorBox"></div>
        <div id="item5" class="colorBox"></div>
    </body>
</html>