Source code

Revision control

Copy as Markdown

Other Tools

Test Info: Warnings

<title>Test that scaled elements with scrolled contents don't repaint unnecessarily when we scroll inside them (1.1 scale)</title>
<script src="/tests/SimpleTest/SimpleTest.js"></script>
<script src="/tests/SimpleTest/paint_listener.js"></script>
<link rel="stylesheet" type="text/css" href="/tests/SimpleTest/test.css"/>
<body onload="setPrefAndStartTest()">
<div id="t" style="transform: scale(1.1, 1.1); transform-origin:top left; width:200px; height:100px; background:yellow; overflow:hidden">
<div style="height:40px;"></div>
<div id="e" style="height:30px; background:lime"></div>
<div style="height:300px; background:yellow"></div>
<pre id="test">
<script type="application/javascript">
var t = document.getElementById("t");
var e = document.getElementById("e");
var utils = SpecialPowers.getDOMWindowUtils(window);
function startTest() {
// Do a couple of scrolls to ensure we've triggered activity heuristics
waitForAllPaintsFlushed(function () {
t.scrollTop = 5;
waitForAllPaintsFlushed(function () {
t.scrollTop = 10;
waitForAllPaintsFlushed(function () {
// Clear paint state now and scroll again.
t.scrollTop = 20;
waitForAllPaintsFlushed(function () {
var painted = utils.checkAndClearPaintedState(e);
is(painted, false, "Fully-visible scrolled element should not have been painted");
function setPrefAndStartTest() {
{"set": [["layers.single-tile.enabled", false]]},
// Need a timeout here to allow paint unsuppression before we start the test
function() {
setTimeout(startTest, 0);