Blitz - WPT: object-view-box-auto-size-relayout.html

wpt / css / css-images / object-view-box-auto-size-relayout.html

/css/css-images/object-view-box-auto-size-relayout.html

<!DOCTYPE html>
<html class="reftest-wait">
<title>Changing object-view-box on an auto-sized element triggers relayout</title>
<link rel="match" href="object-view-box-auto-size-relayout-ref.html">
<link rel="help" href="https://drafts.csswg.org/css-images-4/#the-object-view-box">

<style>
  canvas {
    display: block;
    width: 100px;
    height: auto;
  }
</style>
<body>
<canvas id="canvas" width="100" height="100"></canvas>
<script>
  var ctx = document.getElementById("canvas").getContext("2d");
  ctx.fillStyle = "red";
  ctx.fillRect(0, 0, 100, 100);

  function afterFrame(callback)
  {
    requestAnimationFrame(() => requestAnimationFrame(callback));
  }

  // Let the canvas lay out and paint at its natural 100x100 (1:1) size first,
  // then crop away the bottom half. Since height is auto and there's no
  // explicit aspect-ratio, the used height is derived from the cropped
  // (2:1) intrinsic ratio, so this must trigger a relayout, not just a repaint.
  window.onload = () => {
    afterFrame(() => {
      canvas.style.objectViewBox = "inset(0px 0px 50px 0px)";
      afterFrame(() => {
        document.documentElement.classList.remove("reftest-wait");
      });
    });
  };
</script>
</body>
</html>

/css/css-images/object-view-box-auto-size-relayout-ref.html

<!DOCTYPE html>
<html>
<style>
  div {
    display: block;
    width: 100px;
    height: 50px;
    background-color: red;
  }
</style>
<div></div>