test_fixed_bg_scrolling_repaints.html

mozilla-central/layout/base/tests/chrome/test_fixed_bg_scrolling_repaints.html

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Test Info: Warnings

This test gets skipped with pattern: os == 'android'
Manifest: layout/base/tests/chrome/chrome.toml

<!DOCTYPE HTML>

<html>

<head>

  <title>Test that we don't get unnecessary repaints with fixed backgrounds</title>

  <script src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>

  <script src="chrome://mochikit/content/tests/SimpleTest/paint_listener.js"></script>

  <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>

</head>

<!-- Need a timeout here to allow paint unsuppression before we start the test -->

<body onload="setTimeout(startTest,0)" style="background:url(blue-32x32.png) top left no-repeat fixed; background-size: 100px 2000px; overflow:hidden;">

<div style="height: 2048px"></div>

<pre id="test">

<script type="application/javascript">

SimpleTest.waitForExplicitFinish();

var utils = window.windowUtils;

function startTest() {

  // Do a scroll to ensure we trigger activity heuristics.

  document.documentElement.scrollTop = 1;

  waitForAllPaintsFlushed(function () {

    document.documentElement.scrollTop = 0;

    waitForAllPaintsFlushed(function () {

      // Clear paint state and scroll down

      utils.checkAndClearPaintedState(document.documentElement);

      document.documentElement.scrollTop = 100;

      waitForAllPaintsFlushed(function () {

        // Make sure nothing painted

        var painted = utils.checkAndClearPaintedState(document.documentElement);

        is(painted, false, "Fixed background should not have been painted when scrolled");

        SimpleTest.finish();

});

});

});

</script>

</pre>

</body>

</html>