<!DOCTYPE html>
<script src='../../resources/gesture-util.js'></script>
<script src="../../resources/testharness.js"></script>
<script src="../../resources/testharnessreport.js"></script>
<div style="height:900px;width:2400px">
<div style="background-color:red;height:900px;width:1200px;position:relative;left:0px;top:0px"></div>
<div style="background-color:green;height:900px;width:1200px;position:relative;left:1200px;top:-900px"></div>
</div>
<div style="height:900px;width:2400px">
<div style="background-color:blue;height:900px;width:1200px;position:relative;left:0px;top:0px"></div>
<div style="background-color:yellow;height:900px;width:1200px;position:relative;left:1200px;top:-900px"></div>
</div>
<script>
var givenScrollDelta = 2;
// Page scrolls 87.5% of window size (excluding scrollbars).
var expectedScrollTop = (
document.documentElement.clientHeight * MIN_FRACTION_TO_STEP_WHEN_PAGING
);
var expectedScrollLeft = (
document.documentElement.clientWidth * MIN_FRACTION_TO_STEP_WHEN_PAGING
);
var last_event = null;
var source = GestureSourceType.MOUSE_INPUT;
const numTicks = givenScrollDelta / pixelsPerTick();
const expectedWheelDelta = numTicks * LEGACY_MOUSE_WHEEL_TICK_MULTIPLIER;
function mousewheelHandler(e) {
assert_equals(last_event, null);
last_event = e;
}
promise_test(async () => {
document.body.addEventListener("mousewheel", mousewheelHandler, false);
const scrollend_promise = waitForScrollendEvent(document);
// Wheel event will scroll by one page
await smoothScrollWithXY(
givenScrollDelta, givenScrollDelta, 100, 110, source,
SPEED_INSTANT, false, true
);
await scrollend_promise;
// There is some minor inconsistency between main and compositor threads in
// which direction they round so allow up to one pixel of slack.
assert_approx_equals(
document.scrollingElement.scrollLeft, expectedScrollLeft, 1
);
assert_approx_equals(
document.scrollingElement.scrollTop, expectedScrollTop, 1
);
// When a user operates the device for scrolling to down, wheelDeltaX is negative, otherwise positive.
// https://developer.mozilla.org/en-US/docs/Web/API/Element/mousewheel_event.
assert_equals(last_event.wheelDeltaX, -Math.floor(expectedWheelDelta));
assert_equals(last_event.wheelDeltaY, -Math.floor(expectedWheelDelta));
assert_equals(last_event.wheelDelta, -Math.floor(expectedWheelDelta));
}, 'This test checks one page of scroll on both x and y on document moves the content by 87.5% of window size.');
</script>
Codebase Browser
chromium