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Issue 2320463002:
[SPV2] Implement the blink-side scroll property tree (Closed)
| Index: third_party/WebKit/Source/platform/graphics/paint/README.md |
| diff --git a/third_party/WebKit/Source/platform/graphics/paint/README.md b/third_party/WebKit/Source/platform/graphics/paint/README.md |
| index 1bcf259d6677ba22ffef32e4a2ea023b91a939c3..46f4a0c7867cb473a25d908c62db7a7ab7e7b194 100644 |
| --- a/third_party/WebKit/Source/platform/graphics/paint/README.md |
| +++ b/third_party/WebKit/Source/platform/graphics/paint/README.md |
| @@ -93,6 +93,22 @@ The raster region defined by a node is the rounded rect transformed to the |
| root space, intersects with the raster region defined by its parent clip node |
| (if not root). |
| +### Scrolling |
| + |
| +Each paint chunk is associated with a [scroll node](ScrollPaintPropertyNode.h) |
|
chrishtr
2016/09/08 20:43:59
Always? Even for a page that has no scrolling?
pdr.
2016/09/08 23:16:26
This is due to the no-op scroll node we add at the
|
| +which defines information about how a subtree scrolls so threads other than the |
| +main thread can perform scrolling. Scroll information includes: |
| + |
| +* Which directions, if any, are scrollable by the user. |
| +* A reference to a [transform node](TransformPaintPropertyNode.h) which contains |
| +a 2d scroll offset. |
| +* The extent that can be scrolled. For example, an overflow clip of size 7x9 |
| +with scrolling contents of size 7x13 can scroll 4px vertically and none |
| +horizontally. |
| + |
| +To ensure geometry operations are simple and only deal with transforms, the |
| +scroll offset is stored as a 2d transform in the transform tree. |
| + |
| ### Effects |
| Each paint chunk is associated with an [effect node](EffectPaintPropertyNode.h), |
