Make IFRAME_SEAMLESS child documents inherit styles from their parent iframe element
https://bugs.webkit.org/show_bug.cgi?id=85940
Reviewed by Ojan Vafai.
Source/WebCore:
The HTML5 <iframe seamless> spec says:
In a CSS-supporting user agent: the user agent must, for the purpose of CSS property
inheritance only, treat the root element of the active document of the iframe
element's nested browsing context as being a child of the iframe element.
(Thus inherited properties on the root element of the document in the
iframe will inherit the computed values of those properties on the iframe
element instead of taking their initial values.)
Initially I implemented this support to the letter of the spec. However, doing so I learned
that WebKit has a RenderStyle for the Document Node, not just the root element of the document.
In this RenderStyle on the Document, we add a bunch of per-document styles from settings
including designMode.
This change makes StyleResolver::styleForDocument inherit style from the parent iframe's
style, before applying any of these per-document styles. This may or may not be correct
depending on what behavior we want for rtl-ordering, page-zoom, locale, design mode, etc.
For now, we continue to treat the iframe's document as independent in these regards, and
the settings on that document override those inherited from the iframe.
Also, intially when making this work, I added redirects in recalcStyle and scheduleStyleRecalc
from the child document to the parent document in the case of seamless (since the parent
document effectively manages the style resolve and layout of the child in seamless mode).
However, I was not able to find a test which depended on this code change, so in this final patch
I have removed both of these modifications and replaced them with FIXMEs. Based on discussions
with Ojan and James Robinson, I believe both of those changes may eventually be wanted.
This change basically does 3 things:
1. Makes StyleResolver::styleForDocument inherit from the parent iframe.
2. Makes any recalcStyle calls on the iframe propogate down into the child document (HTMLIFrameElement::didRecalcStyle).
3. Makes Document::recalcStyle aware of the fact that the Document's style *can* change
for reasons other than recalcStyle(Force).
I'm open to more testing suggestions, if reviewers have settings on the Document's style
that you want to make sure we inherit from the parent iframe, or don't inherit, etc.
I view this as a complete solution to this aspect of the current <iframe seamless> spec,
but likely not the last code we will write for this aspect of the seamless feature. :)
Tested by fast/frames/seamlesss/seamless-css-cascade.html and seamless-designMode.html
* css/StyleResolver.cpp:
(WebCore::StyleResolver::collectMatchingRulesForList):
* dom/Document.cpp:
(WebCore::Document::scheduleStyleRecalc):
(WebCore::Document::recalcStyle):
* html/HTMLIFrameElement.cpp:
(WebCore::HTMLIFrameElement::HTMLIFrameElement):
(WebCore::HTMLIFrameElement::didRecalcStyle):
(WebCore):
* html/HTMLIFrameElement.h:
(HTMLIFrameElement):
LayoutTests:
This single pass is deceptive. seamless-designMode exists
to make sure that we do not regress application of Document-level
styles in the child document.
* fast/frames/seamless/seamless-css-cascade-expected.txt:
git-svn-id: http://svn.webkit.org/repository/webkit/trunk@116694 268f45cc-cd09-0410-ab3c-d52691b4dbfc
9 files changed
