pull-background-animated-position-3.html

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<!DOCTYPE html>

<html lang="en" class="reftest-wait">

<meta charset="utf-8">

<title>This test fails - Layerization should respect overflow:hidden clips around things with animated position</title>

<style>

div {

  min-height: 50px;

  box-model: border-box;

.first, .second {

  border: 1px solid blue;

  margin: 50px 0;

  position: relative;

.border {

  border: 1px solid black;

.underlap {

  border: 1px solid #088;

  margin-left: 120px;

  width: 80px;

  margin-bottom: -30px;

.clip {

  height: auto;

  overflow: hidden;

  padding: 10px 0 20px;

.animated-position {

  position: relative;

  left: 20px;

  margin-left: 220px;

  width: 100px;

  height: 100px;

  border-color: red;

body {

  margin: 0;

  padding: 0 100px;

  height: 3000px;

</style>

<div class="first" reftest-assigned-layer="page-background">

  <!--

    This is just a regular box, it should end up in the page background layer.

-->

</div>

<div class="underlap">

  <!--

    This item intersects with the scrollable box and is positioned below

    .scrollable, in z-order.

-->

</div>

<div class="clip border">

  <div class="border animated-position reftest-no-paint">

    <!--

      This box starts out above solid white background, but it will move so

      that it intersects .underlap, so it shouldn't pull up a background

      color to begin with so that it doesn't need to invalidate.

-->

  </div>

</div>

<div class="second" reftest-assigned-layer="page-background">

  <!--

    This should share a layer with .first and the page background.

    However, we don't take .animated-position's clip into account when

    layerizing, so .second will be pulled up into its own layer above

    .animated-position. So this test will fail.

-->

</div>

<script>

var animatedLeft = document.querySelector(".animated-position");

function doTest() {

  animatedLeft.style.left = "-40px";

  document.documentElement.removeAttribute("class");

// Layerize #animatedLeft

animatedLeft.offsetLeft;

animatedLeft.style.left = "40px";

animatedLeft.offsetLeft;

animatedLeft.style.left = "60px";

animatedLeft.offsetLeft;

document.addEventListener("MozReftestInvalidate", doTest);

setTimeout(doTest, 200);

</script>