layout/base/tests/chrome/test_scrolling_repaints.html@6474c204b198
layout/base/tests/chrome/test_scrolling_repaints.html
Wed, 31 Dec 2014 06:09:35 +0100
- author
- Michael Schloh von Bennewitz <michael@schloh.com>
- date
- Wed, 31 Dec 2014 06:09:35 +0100
- changeset 0
- 6474c204b198
- permissions
- -rw-r--r--
Cloned upstream origin tor-browser at tor-browser-31.3.0esr-4.5-1-build1
revision ID fc1c9ff7c1b2defdbc039f12214767608f46423f for hacking purpose.
1 <!DOCTYPE HTML>
2 <html>
3 <head>
4 <title>Test that we don't get unnecessary repaints due to subpixel shifts</title>
5 <script type="application/javascript" src="chrome://mochikit/content/tests/SimpleTest/SimpleTest.js"></script>
6 <script type="text/javascript" src="chrome://mochikit/content/tests/SimpleTest/paint_listener.js"></script>
7 <link rel="stylesheet" type="text/css" href="chrome://mochikit/content/tests/SimpleTest/test.css"/>
8 </head>
9 <!-- Need a timeout here to allow paint unsuppression before we start the test -->
10 <body onload="setTimeout(startTest,0)">
11 <div id="t" style="width:400px; height:100px; background:yellow; overflow:hidden">
12 <div style="height:40px;"></div>
13 <div id="e" style="height:30px; background:lime"></div>
14 <div style="height:60.4px; background:pink"></div>
15 </div>
16 <pre id="test">
17 <script type="application/javascript">
18 SimpleTest.waitForExplicitFinish();
20 var t = document.getElementById("t");
21 var e = document.getElementById("e");
22 var utils = window.QueryInterface(Components.interfaces.nsIInterfaceRequestor).
23 getInterface(Components.interfaces.nsIDOMWindowUtils);
25 function startTest() {
26 // Do a scroll to ensure we trigger activity heuristics.
27 waitForAllPaintsFlushed(function () {
28 t.scrollTop = 5;
29 // Scroll down as far as we can, to put our rendering layer at a subpixel offset within the layer
30 waitForAllPaintsFlushed(function () {
31 t.scrollTop = 1000;
32 waitForAllPaintsFlushed(function () {
33 // Clear paint state now and scroll again.
34 utils.checkAndClearPaintedState(e);
35 // scroll up a little bit. This should not cause anything to be repainted.
36 t.scrollTop = t.scrollTop - 10;
37 waitForAllPaintsFlushed(function () {
38 var painted = utils.checkAndClearPaintedState(e);
39 is(painted, false, "Fully-visible scrolled element should not have been painted");
40 SimpleTest.finish();
41 });
42 });
43 });
44 });
45 }
46 </script>
47 </pre>
48 </body>
49 </html>
