| OLD | NEW |
|---|
| 1 <!DOCTYPE html> | 1 <!DOCTYPE html> |
| 2 | 2 |
| 3 <html> | 3 <html> |
| 4 <head> | 4 <head> |
| 5 <style> | 5 <style> |
| 6 .fixed { | 6 .fixed { |
| 7 position: fixed; | 7 position: fixed; |
| 8 width: 50px; | 8 z-index: 1; |
| 9 height: 50px; | |
| 10 } | 9 } |
| 11 | 10 |
| 12 .absolute { | 11 .absolute { |
| 13 position: absolute; | 12 position: absolute; |
| 14 top: 40px; | 13 } |
| 15 left: 40px; | 14 |
| 15 .unscrollable { |
| 16 overflow-x: hidden; |
| 17 overflow-y: hidden; |
| 18 } |
| 19 |
| 20 .box { |
| 21 top: 100px; |
| 22 left: 10px; |
| 23 width: 100px; |
| 16 height: 100px; | 24 height: 100px; |
| 17 width: 100px; | 25 } |
| 18 background-color: gray; | 26 |
| 27 .red { |
| 28 background-color: red; |
| 29 } |
| 30 |
| 31 .lime { |
| 32 background-color: lime; |
| 33 } |
| 34 |
| 35 .composited { |
| 36 -webkit-transform: translatez(0); |
| 19 } | 37 } |
| 20 </style> | 38 </style> |
| 21 | 39 |
| 22 <script type="text/javascript"> | 40 <script type="text/javascript"> |
| 23 if (window.internals) | 41 if (window.internals) |
| 24 window.internals.settings.setAcceleratedCompositingForFixedPositionEnabled
(true); | 42 window.internals.settings.setAcceleratedCompositingForFixedPositionEnabled
(true); |
| 25 | 43 |
| 26 if (window.testRunner) { | 44 if (window.testRunner) { |
| 27 testRunner.dumpAsText(); | 45 testRunner.dumpAsText(); |
| 28 | 46 |
| 29 window.addEventListener("load", function() { | 47 window.addEventListener("load", function() { |
| 30 document.getElementById("layertree").innerText = window.internals.layerT
reeAsText(document); | 48 document.getElementById("layertree").innerText = window.internals.layerT
reeAsText(document); |
| 31 }, false); | 49 }, false); |
| 32 } | 50 } |
| 33 </script> | 51 </script> |
| 34 </head> | 52 </head> |
| 35 | 53 |
| 36 <body> | 54 <body class="unscrollable"> |
| 37 <div style="height: 1000px"> | 55 <div style="height: 4000px"> |
| 38 <p>There should be no layers.</p> | 56 <p>There should be no layers, because the body is unscrollable and there is |
| 57 no need to composite the fixed-position layer.</p> |
| 39 <pre id="layertree"></pre> | 58 <pre id="layertree"></pre> |
| 40 </div> | 59 </div> |
| 41 | 60 |
| 42 <!-- This should not be composited --> | 61 <!-- This should not be composited --> |
| 43 <div class="fixed" style="top: 10px; left: 10px"></div> | 62 <div class="fixed lime box"></div> |
| 44 <!-- And this should not be promoted into a layer --> | |
| 45 <div class="absolute"></div> | |
| 46 </body> | 63 </body> |
| 47 </html> | 64 </html> |
| 48 | 65 |
| OLD | NEW |
|---|
Chromium Code Reviews
Issue 13828004:
Avoid compositing fixed-position elements if they cannot scroll (Closed)
Base URL: svn://svn.chromium.org/blink/trunk