author Markus Stange <>
Fri, 26 Feb 2016 01:29:41 +0100
changeset 323488 c690a0802e0007bb7e58bafeee672c816faa3cf5
parent 323481 e101e6c74b7dc47ed1506b6524b3e5c0bf322b42
permissions -rw-r--r--
Bug 1247854 - Apply the correct scroll clips to the nsDisplayTransform and nsDisplayPerspective of a scrolled perspective item. r=mattwoodrow a=ritu I've decided to fix this in a very explicit way. The only "magic" part that's left is how we decide that the AGR of the perspective item is outside the scrolled frame (and I'm not sure myself how that works). I didn't want to change what scroll clips we set on what items, because the scroll clip really belongs on the perspective item, because that's the item that needs to be clipped, and it should also be the item that should be scrolled if it weren't for the fact that APZ wouldn't know that it should apply the perspective transform before the APZ transform. MozReview-Commit-ID: BBw8VPohQI4

<!DOCTYPE html>
<html reftest-async-scroll>
<meta charset="utf-8">
<title>Active opacity should be rendered if it's inside the display port, even if it's currently offscreen</title>


.scrollbox {
  border: 1px solid black;
  width: 200px;
  height: 200px;
  overflow: hidden;

.scrolledContent {
  height: 1000px;

.opacity {
  will-change: opacity;
  opacity: 0.5;
  margin-top: 250px;
  width: 100px;
  height: 100px;
  box-sizing: border-box;
  border: 1px solid blue;


<div class="scrollbox"
     reftest-displayport-x="0" reftest-displayport-y="0"
     reftest-displayport-w="200" reftest-displayport-h="1000"
     reftest-async-scroll-x="0" reftest-async-scroll-y="150">
  <div class="scrolledContent">
    <div class="opacity"></div>