<!DOCTYPE html>
<title>Layout Instability: no shift in pointerdown becoming dragging</title>
<link rel="help" href="https://wicg.github.io/layout-instability/" />
<style>
body { margin: 0; }
#draggable {
top:50px;
left:50px;
width:50px;
height:50px;
background-color:blue;
position:absolute
}
</style>
<div id="draggable" ></div>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<script src="/resources/testdriver.js"></script>
<script src="/resources/testdriver-actions.js"></script>
<script src="/resources/testdriver-vendor.js"></script>
<script src="resources/util.js"></script>
<script>
const draggable = document.getElementById("draggable");
draggable.addEventListener('touchmove', function(event) {
let touch = event.targetTouches[0];
// Move the element when the finger moves.
draggable.style.top = touch.pageY - 25 + 'px';
event.preventDefault();
}, false);
generateTouchDragSequence = () => new test_driver.Actions()
.addPointer("touch1", "touch")
.pointerMove(0, 0, {origin: draggable})
.pointerDown()
.pointerMove(0, 15, {origin: draggable})
.pause(100)
.pointerMove(0, 30, {origin: draggable})
.pause(100)
.pointerMove(0, 45, {origin: draggable})
.pause(100)
.pointerUp()
.pause(100);
promise_test(async(test) => {
const watcher = new ScoreWatcher;
let eventWatcher = new EventWatcher(test, draggable, ["pointerup"]);
let donePromise = eventWatcher.wait_for(["pointerup"], { record: 'all' });
// Wait for the initial render to complete.
await waitForAnimationFrames(2);
// Send pointer events for a touch drag.
await generateTouchDragSequence().send();
// wait for pointerUp before running the test
await donePromise;
// Touch moves which drag the objects should be counted as the excluding inputs
// for the layout shift.
assert_greater_than(watcher.score, 0);
assert_equals(watcher.scoreWithInputExclusion, 0);
}, "No Shift in pointerdown reported when it becomes a touch drag.");
</script>