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| (Empty) |
| 1 <!DOCTYPE html> | |
| 2 <html> | |
| 3 | |
| 4 <head> | |
| 5 <script src="../../fast/repaint/resources/text-based-repaint.js"></script> | |
| 6 <style> | |
| 7 | |
| 8 .fixedContainer { | |
| 9 position: fixed; | |
| 10 overflow:hidden; | |
| 11 background-color: #a0a0a0; | |
| 12 bottom: 0px; | |
| 13 left: 0px; | |
| 14 width:400px; | |
| 15 height: 100px; | |
| 16 } | |
| 17 | |
| 18 #foo { | |
| 19 width:200px; | |
| 20 height: 100px; | |
| 21 background-color: #00a0a0; | |
| 22 transform:translateZ(0); | |
| 23 } | |
| 24 </style> | |
| 25 | |
| 26 <script> | |
| 27 if (window.internals) { | |
| 28 /* Note carefully, compositing for fixed position is _disabled_ here */ | |
| 29 internals.settings.setPreferCompositingToLCDTextEnabled(false); | |
| 30 } | |
| 31 | |
| 32 function repaintTest() | |
| 33 { | |
| 34 window.scrollTo(0, 100); | |
| 35 } | |
| 36 </script> | |
| 37 </head> | |
| 38 | |
| 39 <body style="height:4000px;" onload="runRepaintTest()"> | |
| 40 <!-- | |
| 41 Among other duplicate bugs: https://code.google.com/p/chromium/issues/det
ail?id=151734 | |
| 42 | |
| 43 In the current code, a layer may actually be composited, but not have its
own backing store. | |
| 44 In these cases, the layer paints into its composited ancestor with a back
ing store. | |
| 45 For fixed-position elements, however, this goes wrong because no other co
de | |
| 46 realizes that there is a software-painted fixed-position element. As a r
esult, | |
| 47 the composited parent does not receive repaint invalidations, and the fix
ed-position | |
| 48 element incorrectly appears to be fixed to the composited element rather
than the viewport. | |
| 49 | |
| 50 The scenario that reproduces this: A fixed position element that has an
overflow-clip with | |
| 51 a composited child. In this case, the fixed-position element needs to be
composited. | |
| 52 However, this is one of the few reasons that does not require that the co
mposited layer needs | |
| 53 its own backing store. | |
| 54 --> | |
| 55 | |
| 56 <!-- Scrolling should not cause either div to move around on the viewport. --> | |
| 57 <div class="fixedContainer"> | |
| 58 <div id="foo"></div> | |
| 59 </div> | |
| 60 </body> | |
| 61 | |
| 62 </html> | |
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Chromium Code Reviews
Issue 708213002:
Remove the HasOwnBackingButPaintsIntoAncestor compositing state. (Closed)
Base URL: svn://svn.chromium.org/blink/trunk