<!doctype html>
<title>Event coalescing under load</title>
<!--
This test is optional because event coalescing under load is an optional
spec requirement: https://w3c.github.io/pointerevents/#coalesced-events
-->
<meta name="variant" content="?mouse">
<meta name="variant" content="?pen">
<meta name="variant" content="?touch">
<meta name="viewport" content="width=device-width">
<meta name="timeout" content="long">
<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="pointerevent_support.js"></script>
<style>
#target {
width: 100px;
height: 100px;
touch-action: none;
}
</style>
<div id="target"></div>
<script>
"use strict";
const pointer_type = location.search.substring(1);
const target = document.getElementById("target");
// Busy-loop load parameters:
const load_initial_ms = 5;
const load_multiplier = 4;
const load_max_ms = 500;
// Max total delay = 5+20+80+320 = 425ms
// https://w3c.github.io/pointerevents/#coalesced-events
function checkCoalescedMoveEventAttributes(event) {
let coalesced_events = event.getCoalescedEvents();
assert_greater_than_equal(coalesced_events.length, 1,
"pointermove.getCoalescedEvents() has at least 1 entry");
for (let i = 0; i < coalesced_events.length; i++) {
let coalesced_event = coalesced_events[i];
assert_equals(coalesced_event.isTrusted, true,
"coalesced_event.isTrusted is true");
assert_equals(coalesced_event.bubbles, false,
"coalesced_event.bubbles is false");
assert_equals(coalesced_event.cancelable, false,
"coalesced_event.cancelable is false");
assert_equals(coalesced_event.pointerId, event.pointerId,
"coalesced_event.pointerId matches the same in the container event");
assert_equals(coalesced_event.pointerType, event.pointerType,
"coalesced_event.pointerType matches the same in the container event");
assert_equals(coalesced_event.isPrimary, event.isPrimary,
"coalesced_event.isPrimary matches the same in the container event");
assert_equals(coalesced_event.target, event.target,
"coalesced_event.target matches the same in the container event");
if (i > 0) {
assert_greater_than_equal(coalesced_event.timeStamp,
coalesced_events[i-1].timeStamp,
"coalesced_event.timeStamp must be ascending");
}
}
}
let coalesced_event_received = false;
promise_test(async t => {
let current_busyloop_ms = load_initial_ms;
target.addEventListener("pointerdown", event => {
// Every pointerdown blocks the main thread for a certain time limit,
// and then increases the time limit for next round in case the
// current limit fails to cause event coalescing.
let start = performance.now();
while (performance.now() < start + current_busyloop_ms)
continue;
current_busyloop_ms *= load_multiplier;
});
target.addEventListener("pointermove", t.step_func(event => {
checkCoalescedMoveEventAttributes(event);
if (event.getCoalescedEvents().length > 1)
coalesced_event_received = true;
}));
// Repeatedly send a long action sequence until either a coalesced event is
// encountered or the busyloop becomes too long.
while (!coalesced_event_received && current_busyloop_ms < load_max_ms) {
let pointerup_promise = getEvent("pointerup", target);
let actions = new test_driver.Actions()
.addPointer("TestPointer", pointer_type)
.pointerMove(0, 0, { origin: target })
.pointerDown();
for (let i = 0; i < 5; i++) {
actions = actions.pointerMove(20, 20, { origin: target })
.pointerMove(0, 0, { origin: target });
}
actions = actions.pointerUp();
await actions.send();
await pointerup_promise;
}
assert_true(coalesced_event_received, "Coalesed pointermoves received");
}, "Coalesced pointermoves under load");
</script>
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