Scroll position is lost after hide/show element
https://bugs.webkit.org/show_bug.cgi?id=72852
Source/WebCore:
Maintain the scroll position of an overflowing element in the ElementRareData when the scrollable
RenderLayer is destroyed, which can be used to restore the scroll position if the same element gets
back a RenderLayer.
WebKit behaviour will be the same as Firefox and IE. It differs from Opera as it does not reset the
scroll position when an element is moved to another location in the same document. However Opera resets
the scroll position for elements moved to another document, which matches other browsers.
Patch by Rakesh KN <rakesh.kn@motorola.com> on 2012-04-02
Reviewed by Julien Chaffraix.
Test: fast/overflow/scroll-div-hide-show.html
* dom/Element.cpp:
(WebCore::Element::removedFromDocument):
Reset the saved scroll offset if the node is moved to another location in the same document or another one.
(WebCore::Element::savedLayerScrollOffset):
(WebCore::Element::setSavedLayerScrollOffset):
* dom/Element.h:
Add helper functions to access the layer scroll offset from the element's rare data.
* dom/ElementRareData.h:
(ElementRareData):
Add the scroll offset book-keeping.
* rendering/RenderLayer.cpp:
(WebCore::RenderLayer::RenderLayer):
Restore the scroll offset.
(WebCore::RenderLayer::~RenderLayer):
Store the scroll offset if document is not being destroyed.
LayoutTests:
Patch by Rakesh KN <rakesh.kn@motorola.com> on 2012-04-02
Reviewed by Julien Chaffraix.
* fast/overflow/scroll-div-hide-show-expected.txt: Added.
* fast/overflow/scroll-div-hide-show.html: Added.
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@112919 268f45cc-cd09-0410-ab3c-d52691b4dbfc
8 files changed
