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// Assert that the user agent under test supports AnimationTrigger.
// AnimationTrigger tests should do this sanity check before proceeding.
function assertAnimationTriggerSupport() {
assert_true(document.documentElement.style.animationTrigger !== undefined);
}
const setScrollTop = (scroller, y) => {
const scrollend_promise =
waitForScrollEndFallbackToDelayWithoutScrollEvent(scroller);
scroller.scrollTop = y;
return scrollend_promise;
}
function getRangeBoundariesForTest(trigger_start, trigger_end,
exit_start, exit_end, scroller) {
let rangeBoundaries = {
scroller: scroller,
offsetWithinTriggerRange: (trigger_start + trigger_end) / 2,
offsetAboveTriggerRange: trigger_start - 10,
offsetBelowTriggerRange: trigger_end + 10,
offsetAboveExitRange: exit_start - 10,
offsetBelowExitRange: exit_end + 10,
};
rangeBoundaries.enterTriggerRange = async () => {
return setScrollTop(rangeBoundaries.scroller,
rangeBoundaries.offsetWithinTriggerRange);
};
rangeBoundaries.exitTriggerRangeAbove = async () => {
return setScrollTop(rangeBoundaries.scroller,
rangeBoundaries.offsetAboveTriggerRange);
};
rangeBoundaries.exitTriggerRangeBelow = async () => {
return setScrollTop(rangeBoundaries.scroller,
rangeBoundaries.offsetBelowTriggerRange);
};
rangeBoundaries.exitExitRangeAbove = async () => {
return setScrollTop(rangeBoundaries.scroller,
rangeBoundaries.offsetAboveExitRange);
};
rangeBoundaries.exitExitRangeBelow = async () => {
return setScrollTop(rangeBoundaries.scroller,
rangeBoundaries.offsetBelowExitRange);
};
return rangeBoundaries;
}
// Helper function for animation-trigger tests. Aims to perform a scroll and
// observe the animation events indicated by |events_of_interest| and
// |events_should_fire|
async function testAnimationTrigger(test, scroll_fn, target,
events_of_interest, events_should_fire) {
assertAnimationTriggerSupport();
let evt_promises = [];
for (let idx = 0; idx < events_of_interest.length; idx++) {
const evt = events_of_interest[idx];
const animationevent_promise = new Promise((resolve) => {
const watcher_func = () => {
if (!events_should_fire[idx]) {
test.unreached_func(`received unexpected event: ${evt}.`)();
}
resolve();
}
target.addEventListener(evt, watcher_func,
{ once: true });
// If we are not expecting the event, just wait for 3 frames before
// continuing the test.
if (!events_should_fire[idx]) {
waitForAnimationFrames(3).then(() => {
target.removeEventListener(evt, watcher_func);
resolve();
});
}
});
evt_promises.push(animationevent_promise);
}
await scroll_fn();
await Promise.all(evt_promises);
}
function computeContainOffset(scroller, subject, pct) {
const contain_start = subject.offsetTop + subject.offsetHeight
- scroller.offsetTop - scroller.clientHeight;
const contain_end = subject.offsetTop - scroller.offsetTop;
return contain_start + (pct / 100) * (contain_end - contain_start);
}
function setupAnimationAndTrigger(target, subject, duration) {
const animation = new Animation(
new KeyframeEffect(
target,
[
{ transform: "scale(1)", backgroundColor: "yellow" },
{ transform: "scale(2)", backgroundColor: "yellow" },
],
{ duration: duration, fill: "both" }
));
let trigger = new AnimationTrigger({
behavior: "alternate",
timeline: new ViewTimeline({ subject: subject, axis: "y" }),
rangeStart: "contain 0%",
rangeEnd: "contain 100%"
});
trigger.addAnimation(animation);
}
async function waitForAnimation(targetCurrentTime, animation) {
return new Promise(resolve => {
function waitForCurrentTime() {
if ((targetCurrentTime - animation.currentTime) * animation.playbackRate <= 0) {
resolve();
return;
}
requestAnimationFrame(waitForCurrentTime);
}
waitForCurrentTime();
});
}