1.1 --- /dev/null Thu Jan 01 00:00:00 1970 +0000
1.2 +++ b/layout/base/tests/chrome/test_scrolling_repaints.html Wed Dec 31 06:09:35 2014 +0100
1.3 @@ -0,0 +1,49 @@
1.4 +<!DOCTYPE HTML>
1.5 +<html>
1.6 +<head>
1.7 + <title>Test that we don't get unnecessary repaints due to subpixel shifts</title>
1.8 + <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
1.9 + <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/paint_listener.js"></script>
1.10 + <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
1.11 +</head>
1.12 +<!-- Need a timeout here to allow paint unsuppression before we start the test -->
1.13 +<body onload="setTimeout(startTest,0)">
1.14 +<div id="t" style="width:400px; height:100px; background:yellow; overflow:hidden">
1.15 + <div style="height:40px;"></div>
1.16 + <div id="e" style="height:30px; background:lime"></div>
1.17 + <div style="height:60.4px; background:pink"></div>
1.18 +</div>
1.19 +<pre id="test">
1.20 +<script type="application/javascript">
1.21 +SimpleTest.waitForExplicitFinish();
1.22 +
1.23 +var t = document.getElementById("t");
1.24 +var e = document.getElementById("e");
1.25 +var utils = window.QueryInterface(Components.interfaces.nsIInterfaceRequestor).
1.26 + getInterface(Components.interfaces.nsIDOMWindowUtils);
1.27 +
1.28 +function startTest() {
1.29 + // Do a scroll to ensure we trigger activity heuristics.
1.30 + waitForAllPaintsFlushed(function () {
1.31 + t.scrollTop = 5;
1.32 + // Scroll down as far as we can, to put our rendering layer at a subpixel offset within the layer
1.33 + waitForAllPaintsFlushed(function () {
1.34 + t.scrollTop = 1000;
1.35 + waitForAllPaintsFlushed(function () {
1.36 + // Clear paint state now and scroll again.
1.37 + utils.checkAndClearPaintedState(e);
1.38 + // scroll up a little bit. This should not cause anything to be repainted.
1.39 + t.scrollTop = t.scrollTop - 10;
1.40 + waitForAllPaintsFlushed(function () {
1.41 + var painted = utils.checkAndClearPaintedState(e);
1.42 + is(painted, false, "Fully-visible scrolled element should not have been painted");
1.43 + SimpleTest.finish();
1.44 + });
1.45 + });
1.46 + });
1.47 + });
1.48 +}
1.49 +</script>
1.50 +</pre>
1.51 +</body>
1.52 +</html>
