
<!DOCTYPE html>
<html class="reftest-wait">
<meta charset="UTF-8">
<title>reverse running animation</title>
<link rel="match" href="reverse-running-animation-ref.html">
<script src="/common/reftest-wait.js"></script>
<script src="../../testcommon.js"></script>
<style>
  #box {
    background: green;
    height: 40px;
    width: 40px;
  }
</style>
<body>
  <div id="box"></div>
  <p id="notes">
    This test animates the box color from green to red and reverses the play
    direction shortly after the midpoint. If the box remains red, the test
    failed.
  </p>
</body>
<script>
  onload = async function() {
    const box = document.getElementById('box');
    const duration = 10000;
    const anim =
        box.animate({ bacground: [ 'green', 'red' ] },
                    { duration: duration, easing: 'steps(2, jump-none)' });
    anim.currentTime = duration / 2;
    anim.ready.then(() => {
      const startTime = anim.timeline.currentTime;
      waitForAnimationFrames(2).then(() => {
        anim.reverse();
        anim.ready.then(() => {
          const reversalTime = anim.timeline.currentTime;
          const forwardPlayingTime = reversalTime - startTime;
          const checkIfDone = () => {
            if (anim.timeline.currentTime - reversalTime > forwardPlayingTime)
              takeScreenshot();
            else
              requestAnimationFrame(checkIfDone);
          };
          requestAnimationFrame(checkIfDone);
        });
      });
    });
  };
</script>
