track-cues-cuechange.html | Explore in Territory

<!DOCTYPE html>
<title>TextTrack's cues are indexed and updated in order during video playback</title>
<meta name="timeout" content="long">
<script src="/common/media.js"></script>
<script src="/resources/testharness.js"></script>
<script src="/resources/testharnessreport.js"></script>
<video>
    <track src="resources/cues-chrono-order.vtt" kind="captions" default>
    <script>
    // Use the cuechange event on TextTrack.
    async_test(function(t) {
        var video = document.querySelector("video");
        var testTrack = document.querySelector("track");

        video.src = getVideoURI("/media/test");
        video.oncanplaythrough = t.step_func(attemptTests);

        function attemptTests() {
            assert_equals(testTrack.track.cues.length, 3);
            testTrack.oncuechange = t.step_func(cueChangedFromTrackElement);
            video.play();
        }

        var currentCueIndex;
        var cueChangeCount = 0;
        function cueChangedFromTrackElement() {
            currentCueIndex = Math.floor(cueChangeCount / 2);
            currentCue = event.target.track.cues[currentCueIndex];
            if (cueChangeCount % 2 == 0) {
                // Cue entered.
                assert_equals(currentCue, testTrack.track.activeCues[0]);
                assert_equals(currentCue.id, (currentCueIndex + 1).toString());
            }

            ++cueChangeCount;
            if (cueChangeCount == testTrack.track.cues.length * 2)
                t.done();
        }
    });
    </script>
</video>

chromium/third_party/blink/web_tests/external/wpt/html/semantics/embedded-content/media-elements/track/track-element/track-cues-cuechange.html